[Federal Register Volume 87, Number 77 (Thursday, April 21, 2022)]
[Proposed Rules]
[Pages 23920-24023]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-06423]
[[Page 23919]]
Vol. 87
Thursday,
No. 77
April 21, 2022
Part II
Department of Energy
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10 CFR Parts 429 and 431
Energy Conservation Program: Test Procedures for Walk-In Coolers and
Walk-In Freezers; Proposed Rule
Federal Register / Vol. 87 , No. 77 / Thursday, April 21, 2022 /
Proposed Rules
[[Page 23920]]
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DEPARTMENT OF ENERGY
10 CFR Parts 429 and 431
[EERE-2017-BT-TP-0010]
RIN 1904-AD78
Energy Conservation Program: Test Procedures for Walk-In Coolers
and Walk-In Freezers
AGENCY: Office of Energy Efficiency and Renewable Energy, Department of
Energy.
ACTION: Notice of proposed rulemaking and announcement of public
webinar.
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SUMMARY: The U.S. Department of Energy (``DOE'') proposes to amend the
test procedures for walk-in coolers and walk-in freezers to harmonize
with updated industry standards, revise the test methods to more fully
represent field energy use, and better account for the range of walk-in
cooler and walk-in freezer component equipment designs. DOE also
proposes to revise certain definitions applicable to walk-ins. DOE is
seeking comment from interested parties on the proposal and announcing
a public meeting to collect comments and data on its proposal.
DATES: DOE will accept comments, data, and information regarding this
proposal no later than June 21, 2022. See section V, ``Public
Participation,'' for details. DOE will hold a webinar on Monday, May 9,
from 1:00 p.m. to 5:00 p.m. See section V, ``Public Participation,''
for webinar registration information, participant instructions, and
information about the capabilities available to webinar participants.
ADDRESSES: Interested persons are encouraged to submit comments using
the Federal eRulemaking Portal at www.regulations.gov, under docket
number EERE-2017-BT-TP-0010. Follow the instructions for submitting
comments. Alternatively, interested persons may submit comments by
email to [email protected]. Include docket number EERE-2017-BT-
TP-0010 in the subject line of the message.
No telefacsimiles (``faxes'') will be accepted. For detailed
instructions on submitting comments and additional information on this
process, See section V of this document.
Although DOE has routinely accepted public comment submissions
through a variety of mechanisms, including postal mail and hand
delivery/courier, the Department has found it necessary to make
temporary modifications to the comment submission process in light of
the ongoing coronavirus 2019 (``COVID-19 pandemic''). DOE is currently
suspending receipt of public comments via postal mail and hand
delivery/courier. If a commenter finds that this change poses an undue
hardship, please contact Appliance Standards Program staff at (202)
586-1445 to discuss the need for alternative arrangements. Once the
COVID-19 pandemic health emergency is resolved, DOE anticipates
resuming all of its regular options for public comment submission,
including postal mail and hand delivery/courier.
Docket: The docket, which includes Federal Register notices, public
meeting attendee lists and transcripts (if a public meeting is held),
comments, and other supporting documents/materials, is available for
review at www.regulations.gov. All documents in the docket are listed
in the www.regulations.gov index. However, some documents listed in the
index, such as those containing information that is exempt from public
disclosure, may not be publicly available.
The docket web page can be found at www.regulations.gov/docket/EERE-2017-BT-TP-0010. The docket web page contains instructions on how
to access all documents, including public comments, in the docket. See
section V for information on how to submit comments through
www.regulations.gov.
FOR FURTHER INFORMATION CONTACT:
Dr. Stephanie Johnson, U.S. Department of Energy, Office of Energy
Efficiency and Renewable Energy, Building Technologies Office, EE-2J,
1000 Independence Avenue SW, Washington, DC 20585-0121. Telephone:
(202) 287-1943. Email [email protected].
Mr. Michael Kido, U.S. Department of Energy, Office of the General
Counsel, GC-33, 1000 Independence Avenue SW, Washington, DC 20585-0121.
Telephone: (202) 586-8145. Email: [email protected].
For further information on how to submit a comment, review other
public comments and the docket, or participate in a public meeting (if
one is held), contact the Appliance and Equipment Standards Program
staff at (202) 287-1445 or by email:
[email protected].
SUPPLEMENTARY INFORMATION: DOE proposes to maintain previously approved
incorporations by reference and to incorporate by reference the
following industry standards into part 431:
ANSI/AHRI Standard 420-2008, ``Performance Rating of Forced-
Circulation Free-Delivery Unit Coolers for Refrigeration,'' copyright
2008.
AHRI Standard 1250 (I-P)-2009, ``Standard for Performance Rating of
Walk-in Coolers and Freezers,'' (including Errata sheet dated December
2015), copyright 2009, except Table 15 and Table 16.
AHRI Standard 1250-2020, ``Standard for Performane Rating of Walk-
in Coolers and Freezers,'' copyright 2020.
Copies of AHRI 420-2008, AHRI 1250-2009, and AHRI 1250-2020 can be
obtained from the Air-Conditioning, Heating, and Refrigeration
Institute, 2111 Wilson Boulevard, Suite 500, Arlington, VA 22201, or by
going to www.ahrinet.org.
ANSI/ASHRAE Standard 16-2016, ``Method of Testing for Rating Room
Air Conditioners, Packaged Terminal Air Conditioners, and Packaged
Terminal Heat Pumps for Cooling and Heating Capacity,'' approved
October 31, 2016.
ANSI/ASHRAE Standard 23.1-2010, ``Methods of Testing for Rating the
Performance of Positive Displacement Refrigerant Compressors and
Condensing Units that Operate at Subcritical Temperatures of the
Refrigerant,'' ANSI approved January 28, 2010.
ANSI/ASHRAE Standard 37-2009, ``Methods of Testing for Rating
Electrically Driven Unitary Air-Conditioning and Heat Pump Equipment,''
approved June 24, 2009.
Copies of ANSI/ASHRAE 16, ASHRAE 23.1-2010, and ANSI/ASHRAE 37 can
be obtained from the American Society of Heating, Refrigerating and
Air-Conditioning Engineers, 180 Technology Parkway, Peachtree Corners,
GA 30092, or by going to: www.ashrae.org.
ASTM C518-17, ``Standard Test Method for Steady state Thermal
Transmission Properties by Means of the Heat Flow Meter Apparatus,''
ASTM approved May 1, 2017.
ASTM C1199-14, ``Standard Test Method for Measuring the Steady
state Thermal Transmittance of Fenestration Systems Using Hot Box
Methods,'' ASTM approved February 1, 2014.
Copies of ASTM C518-17 and ASTM C1199-14 can be obtained from the
American Society for Testing and Materials, 100 Barr Harbor Drive, West
Conshohocken, PA 19428-2959, or by going to www.astm.org.
NFRC 102-2020 [E0A0], ``Procedure for Measuring the Stready-State
Thermal Transmittance of Fenestration Systems.''
Copies of NFRC 102-2020 can be obtained from the National
Fenestration Rating Council, 6305 Ivy Lane, Ste. 140, Greenbelt, MD
20770, or by going to www.nfrc.org/.
[[Page 23921]]
See section IV.M of this document for a further discussion of these
standards.
Table of Contents
I. Authority and Background
A. Authority
B. Background
II. Synopsis of the Notice of Proposed Rulemaking
III. Discussion
A. Scope and Definitions
1. Scope
a. Liquid-Cooled Refrigeration Systems
b. Carbon Dioxide Systems
c. Multi-Circuit Single-Packaged Refrigeration Systems
d. Ducted Units
2. Definitions
a. Walk-In Cooler and Walk-in Freezer
b. Doors
c. High-Temperature Refrigeration Systems
d. Ducted Fan Coil Units
e. Multi-Circuit Single-Packaged Refrigeration Systems
f. Attached Split Systems
g. Detachable Single-Packaged System
h. CO2 Unit Coolers
i. Hot Gas Defrost
B. Industry Standards
1. Standards for Determining Thermal Transmittance (U-factor)
2. Standard for Determining R-Value
3. Standards for Determining AWEF
a. Changes Consistent With Subpart R, Appendix C
b. CFR Language Not Adopted in AHRI 1250-2020
c. Changes That May Impact the Determination of AWEF
d. Additional Amendments
C. Proposed Amendments to the Test Procedure in Appendix A for
Measuring the Energy Consumption of Walk-In Doors
1. Procedure for Determining Thermal Transmittance (U-Factor)
a. Reference to NFRC 102 in Place of NFRC 100
b. Exceptions to Industry Test Method for Determining U-Factor
c. Calibration of Hot Box for Measuring U-Factor
2. Additional Definitions
a. Surface Area for Determining Compliance With Standards
b. Surface Area for Determining U-Factor
3. Electrical Door Components
4. Percent Time Off Values
5. EER Values
6. Air Infiltration Reduction
D. Proposed Amendments to the Test Procedure in Appendix A for
Display Panels
E. Proposed Amendments to the Test Procedure in Appendix B for
Panels and Non-Display Doors
1. Specimen Conditioning
2. Total Insulation and Test Specimen Thickness
3. Parallelism and Flatness
4. Insulation Aging
5. Determining Energy Consumption of Panels That Are Not Display
Panels
F. Proposed Amendments to Subpart R, Appendix C, To Determine
Compliance With the Current Energy Conservation Standards
1. Refrigeration Test Room Conditioning
2. Temperature Measurement Requirements
3. Hierarchy of Installation Instructions and Specified
Refrigerant Conditions for Refrigerant Charging and Setting
Refrigerant Conditions
a. Dedicated Condensing Unit Charging Instructions
b. Unit Cooler Charging Instructions
c. Single-Packaged Dedicated System Setup and Charging
Instructions
d. Hierarchy of Setup Conditions if Manufacturer-Specified Setup
Conditions Cannot Be Met
4. Subcooling Requirement for Mass Flow Meters
5. Instrument Accuracy and Test Tolerances
6. CO2 Unit Coolers
7. High-Temperature Unit Coolers
G. Proposal To Establish Appendix C1
1. Off-Cycle Power Consumption
a. Off-Cycle Test Duration and Repetition
b. Off-Cycle Operating Tolerances and Data Collection Rates
c. Off-Cycle Load Points
d. Modification to AWEF Calculations
2. Single-Packaged Dedicated Systems
a. AHRI 1250-2020 Methods for Testing
b. Waivers
c. Suitability of the Single-Packaged Test Methods in AHRI 1250-
2020
d. Single-Packaged Refrigerant Enthalpy Method
e. Multi-Circuit Single-Packaged Dedicated Systems
f. CO2 Single-Packaged Dedicated Systems
3. Detachable Single-Packaged Dedicated Systems
4. Attached Split Systems
5. Systems for High-Temperature Freezer Applications
6. Systems for High-Temperature Applications
7. Variable-, Two-, and Multiple-Capacity Systems
a. Dedicated Condensing Units
b. Indoor Matched Pair and Single-Packaged Units
c. Revision to EER Calculation for Outdoor Variable-Capacity and
Multiple-Capacity Refrigeration Systems
d. Digital Compressors
8. Defrost
a. Adaptive Defrost
b. Hot Gas Defrost
9. Refrigerant Glide
10. Refrigerant Temperature and Pressure Instrumentation
Locations
11. Updates to Default Values for Unit Cooler Parameters
12. Calculations and Rounding
H. Alternative Efficiency Determination Methods
1. Doors
2. Refrigeration Systems
I. Sampling Plan for Enforcement Testing
J. Test Procedure Costs and Impact
1. Doors
2. Panels
3. Refrigeration Systems
K. Compliance Date and Waivers
L. Organizational Changes
IV. Procedural Issues and Regulatory Review
A. Review Under Executive Order 12866 and 13563
B. Review Under the Regulatory Flexibility Act
1. Description of Why Action Is Being Considered
2. Objective of, and Legal Basis for, Rule
3. Description and Estimate of Small Entities Regulated
4. Description and Estimate of Compliance Requirements
a. Doors
b. Panels
c. Refrigeration Systems
5. Duplication, Overlap, and Conflict With Other Rules and
Regulations
6. Significant Alternatives to the Rule
C. Review Under the Paperwork Reduction Act of 1995
D. Review Under the National Environmental Policy Act of 1969
E. Review Under Executive Order 13132
F. Review Under Executive Order 12988
G. Review Under the Unfunded Mandates Reform Act of 1995
H. Review Under the Treasury and General Government
Appropriations Act, 1999
I. Review Under Executive Order 12630
J. Review Under Treasury and General Government Appropriations
Act, 2001
K. Review Under Executive Order 13211
L. Review Under Section 32 of the Federal Energy Administration
Act of 1974
M. Description of Materials Incorporated by Reference
V. Public Participation
A. Participation in the Webinar
B. Procedure for Submitting Prepared General Statements for
Distribution
C. Conduct of the Webinar
D. Submission of Comments
E. Issues on Which DOE Seeks Comment
VI. Approval of the Office of the Secretary
I. Authority and Background
Walk-in coolers and freezers (collectively, ``WICFs'' or ``walk-
ins'') are included in the list of ``covered equipment'' for which DOE
is authorized to establish and amend energy conservation standards and
test procedures. (42 U.S.C. 6311(1)(G)) DOE's energy conservation
standards and test procedures for WICFs are currently prescribed at
subpart R of part 431 of title 10 of the Code of Federal Regulations
(``CFR''). The following sections discuss DOE's authority to establish
test procedures for WICFs and relevant background information regarding
DOE's consideration of test procedures for this equipment.
A. Authority
The Energy Policy and Conservation Act, as amended (``EPCA''),\1\
authorizes DOE to regulate the energy efficiency of a number of
consumer products and certain industrial equipment. (42 U.S.C.
[[Page 23922]]
6291-6317) Title III, Part C \2\ of EPCA, added by Public Law 95-619,
Title IV, section 441(a), established the Energy Conservation Program
for Certain Industrial Equipment, which sets forth a variety of
provisions designed to improve energy efficiency. This covered
equipment includes walk-in coolers and walk-in freezers, the subject of
this document. (42 U.S.C. 6311(1)(G))
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\1\ All references to EPCA in this document refer to the statute
as amended through the Energy Act of 2020, Public Law 116-260 (Dec.
27, 2020).
\2\ For editorial reasons, upon codification in the U.S. Code,
Part C was redesignated Part A-1.
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Under EPCA, the energy conservation program consists essentially of
four parts: (1) Testing, (2) labeling, (3) Federal energy conservation
standards (``ECS''), and (4) certification and enforcement procedures.
Relevant provisions of EPCA include definitions (42 U.S.C. 6311), test
procedures (42 U.S.C. 6314), labeling provisions (42 U.S.C. 6315),
energy conservation standards (42 U.S.C. 6313), and the authority to
require information and reports from manufacturers (42 U.S.C. 6316).
The Federal testing requirements consist of test procedures that
manufacturers of covered equipment must use as the basis for: (1)
Certifying to DOE that their equipment complies with the applicable
energy conservation standards adopted pursuant to EPCA (42 U.S.C.
6316(a); 42 U.S.C. 6295(s)), and (2) making representations about the
efficiency of that equipment (42 U.S.C. 6314(d)). Similarly, DOE must
use these test procedures to determine whether the equipment complies
with relevant standards promulgated under EPCA. (42 U.S.C. 6316(a); 42
U.S.C. 6295(s))
Federal energy efficiency requirements for covered equipment
established under EPCA generally supersede State laws and regulations
concerning energy conservation testing, labeling, and standards. (42
U.S.C. 6316(a) and 42 U.S.C. 6316(b); 42 U.S.C. 6297) DOE may, however,
grant waivers of Federal pre-emption for particular State laws or
regulations, in accordance with the procedures and other provisions of
EPCA. (42 U.S.C. 6316(a))
Under 42 U.S.C. 6314, EPCA sets forth the criteria and procedures
DOE must follow when prescribing or amending test procedures for
covered equipment. EPCA requires that any test procedures prescribed or
amended under this section must be reasonably designed to produce test
results that reflect the energy efficiency, energy use or estimated
annual operating cost of a given type of covered equipment during a
representative average use cycle and requires that test procedures not
be unduly burdensome to conduct. (42 U.S.C. 6314(a)(2))
EPCA also requires that, at least once every 7 years, DOE evaluate
test procedures for each type of covered equipment, including walk-ins,
to determine whether amended test procedures would more accurately or
fully comply with the requirements for the test procedures to not be
unduly burdensome to conduct and be reasonably designed to produce test
results that reflect the energy efficiency, energy use, and estimated
operating costs during a representative average use cycle. (42 U.S.C.
6314(a)(1))
In addition, if the Secretary determines that a test procedure
amendment is warranted, the Secretary must publish proposed test
procedures in the Federal Register and afford interested persons an
opportunity (of not less than 45 days' duration) to present oral and
written data, views, and arguments on the proposed test procedures. (42
U.S.C. 6314(b)) If DOE determines that test procedure revisions are not
appropriate, DOE must publish its determination not to amend the test
procedures. (42 U.S.C. 6314(a)(1)(A)(ii)) DOE is publishing this notice
of proposed rulemaking (``NOPR'') in satisfaction of the 7-year review
requirement specified in EPCA.
B. Background
For measuring walk-in energy use, DOE has established separate test
procedures for the principal components that make up a walk-in (i.e.,
doors, panels, and refrigeration systems), with separate test metrics
for each component. 10 CFR 431.304(b). For walk-in doors and display
panels, the efficiency metric is daily energy consumption, measured in
kilowatt-hours per day (``kWh/day''), which accounts for the thermal
conduction through the door or display panel and the direct and
indirect electricity use of any electrical components associated with
the door. 10 CFR 431.304(b)(1)-(2) and 10 CFR part 431, subpart R,
appendix A, ``Uniform Test Method for the Measurement of Energy
Consumption of the Components of Envelopes of Walk-In Coolers and Walk-
In Freezers'' (``appendix A''). The thermal transmittance through the
door, which inputs into the calculation of thermal conduction, is
determined using National Fenestration Rating Council (``NFRC'') 100-
2010, ``Procedure for Determining Fenestration U-factors'' (``NFRC
100'').
For walk-in non-display panels and non-display doors, DOE codified
in the CFR standards established in EPCA based on the R-value
metric,\3\ expressed in units of (h-ft\2\-[deg]F/Btu),\4\ which is
calculated as the thickness of the panel in inches (``in.'') divided by
the K-factor.\5\ See 10 CFR 431.304(b)(3) and 10 CFR part 431, subpart
R, appendix B, titled ``Uniform Test Method for the Measurement of R-
Value for Envelope Components of Walk-In Coolers and Walk-In Freezers''
(``appendix B''). (See also, 42 U.S.C. 6314(a)(9)(A)) The K-factor is
calculated based on American Society for Testing and Materials
(``ASTM'') C518, ``Standard Test Method for Steady-State Thermal
Transmission Properties by Means of the Heat Flow Meter Apparatus''
(``ASTM C518''), which is incorporated by reference at 10 CFR 431.303.
Id.
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\3\ The R-value is the thermal resistance, or the capacity of an
insulated material to resist heat-flow. See Section 3.3.3 of ASTM
C518. See 42 U.S.C. 6313(f)(1)(C) for the EPCA R-value requirements
for non-display panels and doors.
\4\ These symbols represent the following units of measurement--
h: hour; ft\2\: square foot; [deg]F: degrees Fahrenheit; Btu:
British thermal unit.
\5\ The K-factor represents the thermal conductivity of a
material, or its ability to conduct heat, in units of Btu-in/(h-
ft\2\-[deg]F). See Section 3.3.1 of ASTM C518.
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For walk-in refrigeration systems, the efficiency metric is Annual
Walk-in Energy Factor (``AWEF''), which is the ratio of the total heat,
not including the heat generated by the operation of refrigeration
systems, removed, in Btu, from a walk-in box during one-year period of
usage for refrigeration to the total energy input of refrigeration
systems, in watt-hours, during the same period. AWEF is determined by
conducting the test procedure set forth in American National Standards
Institute (``ANSI'')/Air-Conditioning, Heating, and Refrigeration
Institute (``AHRI'') Standard 1250P (I-P), ``2009 Standard for
Performance Rating of Walk-In Coolers and Freezers,'' (``AHRI 1250-
2009''), with certain adjustments specified in the CFR. See 10 CFR
431.304(b)(4) and 10 CFR part 431 subpart R, appendix C, ``Uniform Test
Method for the Measurement of Net Capacity and AWEF of Walk-In Cooler
and Walk-In Freezer Refrigeration Systems'' (``subpart R, appendix
C''). A manufacturer may also determine AWEF using an alternative
efficiency determination method (``AEDM''). 10 CFR 429.53(a)(2)(iii).
An AEDM enables a manufacturer to utilize computer-based or
mathematical models for purposes of determining an equipment's energy
use or energy efficiency performance in lieu of testing, provided
certain prerequisites have been met. 10 CFR 429.70(f).
On August 5, 2015, DOE published its intention to establish a
working group
[[Page 23923]]
under the Appliance Standards and Rulemaking Federal Advisory Committee
(``ASRAC'') to negotiate energy conservation standards to replace the
standards established in the final rule published on June 3, 2014 (79
FR 32050; ``June 2014 ECS final rule''). 80 FR 46521. The established
working group (``ASRAC Working Group'') assembled its recommendations
into a Term Sheet \6\ (Docket EERE-2015-BT-STD-0016, No. 56) that was
presented to, and approved by, ASRAC on December 18, 2015 (``ASRAC Term
Sheet'').
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\6\ Appliance Standards and Rulemaking Federal Advisory
Committee Refrigeration Systems Walk-in Coolers and Freezers Term
Sheet, available at https://www.regulations.gov/document/EERE-2015-BT-STD-0016-0056.
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The ASRAC Term Sheet provided recommendations for energy
conservation standards to replace standards that had been vacated by
the United States Court of Appeals for the Fifth Circuit in a
controlling order issued August 10, 2015. It also included
recommendations regarding definitions for a number of terms related to
the WICF regulations, as well as recommendations to amend the test
procedure that the ASRAC Working Group viewed as necessary to properly
implement the energy conservation standards recommendations.
Consequently, DOE initiated both an energy conservation standards
rulemaking and a test procedure rulemaking in 2016 to implement these
recommendations. The ASRAC Term Sheet also included recommendations for
future amendments to the test procedures intended to make DOE's test
procedure more fully representative of walk-in energy use.
On December 28, 2016, DOE published a final rule amending the WICF
test procedures (``December 2016 final rule''), consistent with the
ASRAC Term Sheet recommendations and including provisions to facilitate
implementation of energy conservation standards for walk-in components.
81 FR 95758. Subsequently, on July 10, 2017, DOE published a final rule
amending the energy conservation standards for WICF refrigeration
systems (``July 2017 ECS final rule''). 82 FR 31808.
AHRI published an updated industry test standard for walk-in
refrigeration systems in 2020, ``2020 Standard for Performance Rating
of Walk-in Coolers and Freezers,'' (``AHRI 1250-2020''). This test
procedure included updated calculations for the determination of
default values for equipment with electric defrost and hot gas defrost.
DOE published a final rule for hot gas defrost unit coolers on March
26, 2021 (``March 2021 final rule'') that amended the test procedure to
rate hot gas defrost unit coolers using the modified default values for
energy use and heat load contributions in AHRI 1250-2020. These
amendments ensure that ratings for hot gas defrost unit coolers are
consistent with those of electric defrost unit coolers. 86 FR 16027.
Under 10 CFR 431.401, any interested person may submit a petition
for waiver from DOE's test procedure requirements. DOE will grant a
waiver from the test procedure requirements if DOE determines either
that the basic model for which the waiver was requested contains a
design characteristic that prevents testing of the basic model
according to the prescribed test procedures, or that the prescribed
test procedures evaluate the basic model in a manner so
unrepresentative of its true energy consumption characteristics as to
provide materially inaccurate comparative data. 10 CFR 431.401(f)(2).
DOE may grant the waiver subject to conditions, including adherence to
alternate test procedures specified by DOE. Id. DOE has granted interim
waivers and/or waivers to the manufacturers listed in Table I.1 from
either appendix A or subpart R, appendix C.
Table I.1: Manufacturers Who Received a Test Procedure Waiver/Interim Waiver From DOE
----------------------------------------------------------------------------------------------------------------
Waiver from
Manufacturer Subject Case No. appendix
----------------------------------------------------------------------------------------------------------------
Jamison Door Company......................... PTO for Door Motors............. 2017-009 A
HH Technologies.............................. PTO for Door Motors............. 2018-001 A
Senneca Holdings............................. PTO for Door Motors............. 2020-002 A
Hercules..................................... PTO for Door Motors............. 2020-013 A
HTPG......................................... CO2 Unit Coolers................ 2020-009 C
Hussmann..................................... CO2 Unit Coolers................ 2020-010 C
Keeprite..................................... CO2 Unit Coolers................ 2020-014 C
RefPlus, Inc................................. CO2 Unit Coolers................ 2021-006 C
RSG.......................................... Multi-Circuit Single-Package 2022-004 C
Dedicated Systems.
Store It Cold................................ Single-Package Dedicated Systems 2018-002 C
CellarPro.................................... Wine Cellar Refrigeration 2019-009 C
Systems.
Air Innovations.............................. Wine Cellar Refrigeration 2019-010 C
Systems.
Vinotheque................................... Wine Cellar Refrigeration 2019-011 C
Systems.
Vinotemp..................................... Wine Cellar Refrigeration 2020-005 C
Systems.
LRC Coil..................................... Wine Cellar Refrigeration 2020-024 C
Systems.
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On June 17, 2021, DOE published a request for information (``RFI'')
to collect information and data to consider amendments to DOE's test
procedures for walk-ins (``June 2021 RFI''). 86 FR 32332. DOE received
comments in response to the June 2021 RFI from the interested parties
listed in Table I.2.
Table I.2 List of Commenters With Written Submissions in Response to the
June 2021 RFI
------------------------------------------------------------------------
Reference in this
Commenter(s) NOPR Commenter type
------------------------------------------------------------------------
Air-Conditioning, Heating, & AHRI.............. Industry
Refrigeration Institute. Association
Anthony International........... Anthony........... Manufacturer
Appliance Standards Awareness ASAP.............. Efficiency
Project. Organization
[[Page 23924]]
Pacific Gas and Electric CA IOUs........... Utility
Company, San Diego Gas and Association
Electric, and Southern
California Edison;
collectively, the California
Investor-Owned Utilities.
Daikin US Corporation........... Daikin............ Manufacturer
Hussmann Corporation............ Hussmann.......... Manufacturer
Imperial Brown, Inc............. Imperial Brown.... Manufacturer
Keeprite Refrigeration, Inc..... Keeprite.......... Manufacturer
Lennox International............ Lennox............ Manufacturer
National Refrigeration & Air National Manufacturer
Conditioning Canada Corp.. Refrigeration.
Northwest Energy Efficiency NEEA.............. Efficiency
Alliance. Organization
National Fenestration Rating NFRC.............. Industry
Council. Association
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In response to the June 2021 RFI, DOE also received comments
specific to energy conservation standards (``ECS''), which it will
address in a future walk-in ECS rulemaking notice.
A parenthetical reference at the end of a comment quotation or
paraphrase provides the location of the item in the public record.\7\
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\7\ The parenthetical reference provides a reference for
information located in the docket of DOE's rulemaking to develop
test procedures for walk-ins. (Docket No. EERE-2017-BT-TP-0010,
which is maintained at www.regulations.gov). The references are
arranged as follows: Commenter name, comment docket ID number, page
of that document.
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II. Synopsis of the Notice of Proposed Rulemaking
In this NOPR, DOE is proposing to expand the scope of its walk-in
coolers and freezers test procedure to include carbon dioxide
(``CO2'') unit coolers, multi-circuit single-packaged
dedicated systems, and ducted fan coil units. DOE has also tentatively
determined that liquid-cooled refrigeration systems are within the
scope of DOE coverage authority for walk-ins but is not proposing to
add an applicable test procedure at this time.
In this NOPR, DOE is proposing to alter the definitions of walk-in
cooler and walk-in freezer, door, door surface area, and single-
packaged dedicated systems. DOE is also proposing new definitions for
door leaf, hinged vertical door, non-display door, roll-up door,
sliding door, high-temperature refrigeration systems, ducted fan coil
units, multi-circuit single-packaged dedicated systems, attached split
systems, detachable single-packaged dedicated systems, CO2
unit coolers, and hot gas defrost.
In this NOPR, DOE is proposing to make the following revisions to
appendix A: (1) Reference NFRC 102-2020 as the applicable test
procedure to determine door ``U-factor'' in place of NFRC 100 (DOE
proposes to adopt AEDM provisions for doors in 10 CFR 429.53 to allow
calculation of door energy use representations); (2) provide further
detail on and distinguish the area to be used for determining
compliance with standards and the area used to calculate a thermal load
from U-factor; (3) establish a percent time off (``PTO'') specific to
door motors; and (4) reorganize appendix A so that it is easier to
follow.
Additionally, DOE is proposing to modify appendix B to improve test
representativeness and repeatability. Specifically, DOE is proposing to
make the following revisions to appendix B: (1) Reference the updated
industry standard ASTM C518-17; (2) include more detailed provisions
for determining measuring insulation thickness and test specimen
thickness; (3) provide additional guidance on determining parallelism
and flatness of a test specimen; and (4) reorganize appendix B as a
step-by-step procedure so it is easier to follow.
DOE is also proposing to include walk-in doors and walk-in panels
in the list of covered equipment in the same sampling plan for
enforcement testing that is used for walk-in refrigeration systems. See
10 CFR 429.110(e)(2).
DOE is proposing two sets of changes for the refrigeration system
test procedure. One set of changes would be grouped into proposed
revisions to subpart R, appendix C, and the other set of changes is
being proposed through the establishment of a new appendix C1 to
subpart R of part 431 (``appendix C1''). DOE has tentatively determined
that the changes to subpart R, appendix C, would not affect AWEF
ratings and therefore would not require any retesting or
recertification. These proposed changes, if adopted, would be required
starting 180 days after the test procedure final rule is published. DOE
has tentatively determined, however, that the proposed appendix C1
would affect the measurement of energy use; therefore, DOE is proposing
to establish a new metric, AWEF2, in appendix C1 which would require
retesting and recertification. The requirements proposed in appendix
C1, if adopted, would take place on the compliance date of amended
energy conservation standards that DOE may ultimately decide to adopt
as part of a separate rulemaking assessing the technological
feasibility and economic justification for such standards.
DOE is proposing to make the following revisions to subpart R,
appendix C:
(1) Specify refrigeration test room conditions;
(2) provide for a temperature probe exception for small diameter
refrigerant lines;
(3) incorporate a test setup hierarchy for installation
instructions for laboratories to follow when setting up a unit for
test;
(4) allow active cooling of the liquid line in order to achieve the
required 3 [ordm]F subcooling at a refrigerant mass flow meter;
(5) modify instrument accuracy and test tolerances; and
(6) address current test procedure waivers for CO2 unit
coolers tested alone and high-temperature unit coolers tested alone by
incorporating amendments appropriate for this equipment.
Additionally, DOE is proposing a new metric, AWEF2, associated with
a new appendix C1, which would include the proposed changes to subpart
R, appendix C. DOE is proposing the following provisions be included in
appendix C1, which would be required to demonstrate compliance
coincident with the compliance date of any amended energy conservation
standards, should such standards be established:
(1) Adoption of AHRI 1250-2020;
(2) provide for testing single-packaged dedicated systems,
detachable single-packaged dedicated systems, attached split systems,
CO2, variable-, two-, and multiple-capacity dedicated
condensing units, indoor variable-, two- and multiple-capacity matched
pairs,
[[Page 23925]]
matched refrigeration systems for high-temperature applications, and
multi-circuit single-packaged dedicated systems;
(3) add a single-packaged dedicated system refrigerant enthalpy
test procedure; and
(4) add a new energy metric, AWEF2, to reflect the proposed changes
in the test procedure that would result in a significant change to
energy use values.
Table II.1 summarizes the current DOE test procedure, DOE's
proposed changes to the test procedure, the attribution for each
proposed change, and the location of the proposed test procedure.
Table II.1--Summary of Changes in Proposed Test Procedure Relative to Current Test Procedure
----------------------------------------------------------------------------------------------------------------
Current DOE test Proposed test Proposed in
WICF component(s) procedure procedure(s) Attribution appendix
----------------------------------------------------------------------------------------------------------------
Doors and Display Panels........ Incorporates by Incorporates by Reduce test burden. A
reference NFRC 100- reference NFRC 102-
2010 for 2020 for
determining U- determining U-
factor as part of factor and allows
determining energy for AEDMs to be
consumption. used for
determining energy
consumption.
Doors and Display Panels........ Uses surface area Requires that area Improve A
of the door or of the aperture or representative
display panel surface area used values.
external to the to determine the U-
walk-in to convert factor be used to
U-factor into a convert U-factor
conduction load. into a conduction
load.
Doors........................... Uses a percent time Establishes a Improve A
off value of 25 percent time off representative
percent for door value of 97 values and
motors (as they percent specific addresses
are considered to door motors. inconsistent
``other values across
electricity- waivers granted.
consuming
devices'').
Non-display Doors and Panels.... Incorporates by Incorporates by Updates to the B
reference ASTM reference ASTM applicable
C518-04. C518-17. industry test
procedures.
Non-display Doors and Panels.... Does not include Includes detailed Ensure test B
detailed provisions for repeatability.
provisions for determining and
determining and measuring total
measuring total insulation
insulation thickness and test
thickness and test specimen thickness.
specimen thickness.
Non-display Doors and Panels.... Requires that the Provides guidance Ensure test B
test specimen meet on determining repeatability.
a parallelism and parallelism and
flatness tolerance flatness of the
of 0.03 inches
but provides no
guidance on
measurement.
Refrigeration Systems........... Does not include Includes guidance Ensure test C
guidance on test on test room repeatability.
room conditioning. conditioning.
Refrigeration Systems........... Does not include an Includes an Reduce test burden. C
allowance for allowance for
measuring measuring
refrigerant refrigerant
temperatures with temperatures with
surface-mounted surface-mounted
measuring measuring
instruments. instruments for
small diameter
tubes.
Refrigeration Systems........... Does not include Includes guidance Ensure test C
guidance for unit for unit charging repeatability.
charging or a and a setup
setup condition condition
hierarchy. hierarchy.
Refrigeration Systems........... Does not include Includes provisions Improve C
provisions for for testing CO2 representative
testing CO2 unit unit coolers. values.
coolers.
Refrigeration Systems........... Does not include Includes provisions Improve C
provisions for for testing high- representative
testing high- temperature unit values.
temperature unit coolers alone.
coolers alone.
Refrigeration Systems........... Incorporates by Incorporates by Updates to the C1
reference AHRI reference AHRI applicable
1250-2009, ASHRAE 1250-2020, ASHRAE industry test
23.1-2010, and 37, and ASHRAE 16. procedures.
AHRI 420-2008.
Refrigeration Systems........... Single-packaged Includes multiple Improve C1
dedicated systems methods for representative
are tested using testing single- values.
the refrigerant packaged dedicated
enthalpy method systems.
for matched pairs.
Refrigeration Systems........... Does not include Includes provisions Improve C1
provisions for for testing representative
testing attached attached split values.
split systems or systems or
detachable single- detachable single-
packaged dedicated packaged dedicated
systems. systems.
Refrigeration Systems........... Does not include Includes provisions Improve C1
provisions for for testing multi- representative
testing multi- circuit single- values.
circuit single- packaged dedicated
packaged dedicated systems.
systems.
Refrigeration Systems........... Does not include Includes provisions Improve C1
provisions for for testing ducted representative
testing ducted fan fan coil units. values.
coil units.
Refrigeration Systems........... Does not include Includes provisions Improve C1
provisions for for testing high- representative
testing high- temperature values.
temperature matched-pair and
matched-pair and single-packaged
single-packaged dedicated systems.
dedicated systems.
[[Page 23926]]
Refrigeration Systems........... Does not include Includes provisions Improve C1
provisions for for testing of representative
testing of variable, two-, values.
variable- and and multiple-
multiple-capacity capacity dedicated
dedicated condensing units
condensing units and variable, two-
nor variable- and , and multiple-
multiple-capacity capacity outdoor
outdoor matched matched pairs.
pairs.
----------------------------------------------------------------------------------------------------------------
DOE has tentatively determined that the proposed amendments
described in section III of this NOPR would not alter the measured
energy consumption of walk-in doors without motors or the R-value of
walk-in non-display doors and non-display panels or require retesting
or recertification solely as a result of DOE's adoption of the proposed
amendments to the test procedures, if made final. Additionally, DOE has
tentatively determined that the proposed amendments, if made final,
would not increase the cost of testing.
Further, DOE has tentatively determined that the proposed
amendments described in section III of this NOPR would alter the
measured energy consumption or efficiency of walk-in doors with motors
and would only require retesting or recertification because of DOE's
adoption of the proposed amendments to the test procedures, if made
final. Additionally, DOE has tentatively determined that the proposed
amendments, if made final, would not increase the cost of testing for
doors with motors.
DOE has also tentatively determined that the proposed amendments to
subpart R, appendix C, described in section III.F of this NOPR would
not alter the measured efficiency of walk-in refrigeration systems and
would not require retesting or recertification as a result of DOE's
adoption of the proposed amendments to the test procedures, if made
final. Additionally, DOE has tentatively determined that the proposed
amendments, if made final, would not increase the cost of testing.
Finally, DOE has tentatively determined that the proposed
provisions of appendix C1 described in section III.G of this NOPR would
alter the measured efficiency of walk-in refrigeration systems.
However, the proposed procedure in appendix C1 would only require
retesting or recertification when a future energy conservation standard
would take effect. Additionally, DOE has tentatively determined that
the proposed provisions in appendix C1, if made final, would increase
the cost of testing. Tentative cost estimates are discussed in section
III.J of this document.
Discussion of DOE's proposed actions are addressed in detail in
section III of this NOPR.
III. Discussion
In the following sections, DOE proposes certain amendments to its
test procedures for walk-in doors, panels, and refrigeration systems.
For each proposed amendment, DOE provides relevant background
information, explains why the amendment merits consideration, discusses
relevant public comments, and proposes a potential approach.
Many of the refrigeration system test procedure proposals under
consideration in this NOPR stem from recommendations made by the ASRAC
Working Group (see ASRAC Term Sheet Recommendation #6, EERE-2015-BT-
STD-0016, No. 56). The remainder of the refrigeration system, door, and
panel test procedure amendments proposed in this NOPR are in response
to issues identified by DOE and stakeholders in the time since the
publication of the December 2016 final rule, including through
petitions for test procedure waivers.
A. Scope and Definitions
This NOPR applies to the test procedures for ``walk-in coolers and
walk-in freezers.'' DOE defines ``walk-in cooler and walk-in freezer''
as: An enclosed storage space refrigerated to temperatures (1) above 32
[deg]F for walk-in coolers and (2) at or below 32 [deg]F for walk-in
freezers, that can be walked into, and has a total chilled storage area
of less than 3,000 square feet, but excluding equipment designed and
marketed exclusively for medical, scientific, or research purposes. 10
CFR 431.302. (See also 42 U.S.C. 6311(20))
1. Scope
The following sections discuss considerations and proposals
regarding the scope of equipment covered by DOE's test procedures for
walk-ins. As discussed, the DOE test procedures and standards apply to
walk-in refrigeration systems, doors, and panels.
a. Liquid-Cooled Refrigeration Systems
A -liquid-cooled refrigeration system rejects heat during the
condensing process to a liquid that transports the heat to a remote
location. This is in contrast to an air-cooled system, which rejects
heat to ambient air during the condensing process. DOE understands that
liquid-cooled refrigeration systems are typically used in facilities
where either cooling water or glycol is plumbed throughout the building
prior to installation of the refrigeration unit, although it is
possible that some such systems use potable water for condenser cooling
and dispose the water in a drain after it passes through the condenser.
As discussed in the June 2021 RFI, liquid-cooled dedicated condensing
units for walk-ins are readily available for a wide range of capacities
and refrigerants from major walk-in refrigeration system manufacturers
(see for example, Airdyne W-series indoor units (water-cooled), and
Russell (water-cooled, glycol-cooled) \8\ 86 FR 32332, 32334.
---------------------------------------------------------------------------
\8\ See Docket No. EERE-2017-BT-TP-0010-0001, Docket No. EERE-
2017-BT-TP-0010-0002, and Docket No. EERE-2017-BT-TP-0010-0003.
---------------------------------------------------------------------------
DOE notes that the EPCA definition for walk-ins makes no
distinction on how the condenser is cooled. (42 U.S.C. 6311(20)(A))
However, the current DOE test procedure for walk-in refrigeration
systems, which incorporates by reference AHRI 1250-2009, does not
address how to test liquid-cooled systems. Additionally, liquid-cooled
dedicated condensing units are outside the scope of AHRI 1250-2020,
being specifically excluded in section 2.2.4.
In the June 2021 RFI, DOE requested comment on whether it should
consider establishing a test procedure for liquid-cooled walk-in
equipment. 86 FR 32332, 32334. Lennox, AHRI, Keeprite, National
Refrigeration, and Hussmann recommended against establishing a separate
test procedure for liquid-cooled refrigeration systems due to the small
market size for such systems. (Lennox, No. 9 at p. 2; AHRI, No. 11 at
p. 2; Keeprite, No. 12 at p. 1; National
[[Page 23927]]
Refrigeration, No 17 at p. 1; Hussmann, No. 18 at p. 2) Lennox, AHRI,
Keeprite, and Hussmann also explained that the type of coolant used has
the most impact on efficiency for liquid-cooled systems; however,
coolants are not specified by the WICF system manufacturer. These
stakeholders asserted that liquid-cooled systems do not have a large
potential for energy savings since purchasers, rather than WICF
manufacturers, specify the coolant system. (Lennox, No. 9 at p. 2;
AHRI, No. 11 at p. 2; Keeprite, No. 12 at p. 1; Hussmann, No. 18 at p.
2) Keeprite also stated that liquid-cooled systems are generally more
efficient than air cooled models. (Keeprite, No. 12 at p. 1)
ASAP recommended developing a test procedure for liquid-cooled
systems since the systems are currently available in the market and
there are no applicable test procedures. (ASAP, No. 13 at p. 1) ASAP
stated that adopting test methods for liquid-cooled systems would
provide purchasers with comparable ratings regardless of cooling type.
Id. Daikin recommended considering EN 17432, ``Packaged refrigerating
units for walk-in cold rooms--Classification, performance and energy
consumption testing'' (``EN 17432''), which addresses water-cooled and
liquid-cooled refrigeration systems. (Daikin, No. 17 at p. 1)
DOE reiterates that the scope of the walk-in definition includes
liquid-cooled equipment. DOE recognizes the potential benefit of a test
procedure for liquid-cooled walk-ins and the value that a reliable test
procedure can provide to facilitate comparable representations of
energy use for consumers. DOE has tentatively determined that liquid-
cooled refrigeration systems may represent a small portion of the walk-
in market and the potential for energy savings is likely limited.
Therefore, although liquid-cooled refrigeration systems are considered
to be covered equipment, DOE is not proposing to amend its procedures
to include liquid-cooled refrigeration systems at this time.
b. Carbon Dioxide Systems
Currently, the DOE test procedure for walk-in refrigeration systems
does not explicitly define scope based on refrigerant. See 10 CFR
431.301, 10 CFR 431.304, and appendix A. DOE understands that the
current test procedure, which is based on AHRI 1250-2009 (incorporated
by reference, 10 CFR 431.303(b)), specifies test conditions that may
not be consistent with the design and operation of carbon dioxide
(``CO2'') refrigeration systems; i.e., although AHRI 1250-
2009 does not specifically exclude CO2 systems, the test
method is not designed to accommodate such systems.
The DOE test procedure for unit coolers requires testing with a
liquid inlet saturation temperature of 105 [deg]F and a liquid inlet
subcooling temperature of 9 [deg]F, as specified by Tables 15 and 16 of
AHRI 1250-2009. However, CO2 has a critical temperature of
87.8 [deg]F; therefore, it does not coexist as saturated liquid and gas
above this temperature. The liquid inlet saturation temperature of 105
[deg]F and the liquid inlet subcooling temperature of 9 [deg]F
specified in subpart R, appendix C, are not achievable by
CO2 unit coolers. DOE has granted waivers or interim waivers
from subpart R, appendix C, for specific basic models of CO2
unit coolers to the manufacturers listed in Table III.1 of this
document. The alternate test procedure specified in these waivers
modified the liquid inlet saturation temperature to 38 [deg]F and the
liquid inlet subcooling temperature to 5 [deg]F. Pursuant to its waiver
regulations, as soon as practicable after the granting of any waiver,
DOE will publish in the Federal Register a notice of proposed
rulemaking to amend its regulations so as to eliminate any need for the
continuation of such waiver. 10 CFR 431.401(l). As soon thereafter as
practicable, DOE will publish in the Federal Register a final rule to
that effect. Id.
Table III.1--Waivers Granted to Manufacturers of CO2 Walk-In
Refrigeration Systems
------------------------------------------------------------------------
Interim waiver Waiver decision
Manufacturer Federal Register and order Federal
citation Register citation
------------------------------------------------------------------------
Heat Transfer Products Group 85 FR 83927 (Dec. 86 FR 14887 (Mar.
(``HTPG''). 23, 2020). 19, 2021).
Hussmann Corporation 86 FR 10046 (Feb. 86 FR 24606 (May
(``Hussmann''). 18, 2021). 7, 2021).
Keeprite Refrigeration 86 FR 12433 (Mar. 86 FR 24603 (May
(``Keeprite''). 3, 2021). 7, 2021).
RefPlus Inc. (``RefPlus'')...... 86 FR 43633 (Aug.
10, 2021).
------------------------------------------------------------------------
The alternate test procedure granted in the CO2 waivers
and DOE's proposal with respect to refrigeration systems utilizing
CO2 as a refrigerant are further discussed in section
III.F.6 of this document.
As discussed in the June 2021 RFI, all CO2 refrigerant
waiver petitions DOE has thus far received address unit coolers. 86 FR
32332, 32346. However, it is possible that other CO2
refrigeration system configurations may be relevant in the future, e.g.
dedicated condensing units, matched pairs, or single-packaged dedicated
systems. DOE reviewed product literature and other information for
CO2 systems having some of these alternative configurations.
Most of the information identified by DOE pertains to manufacturers
operating in Europe.
In the June 2021 RFI, DOE requested comment on the future expected
use of walk-in refrigeration systems using CO2. 86 FR 32332,
32346. Lennox, AHRI, National Refrigeration, and Hussmann stated that
they are not aware of any transcritical \9\ CO2 dedicated
condensing units available in North America. (Lennox, No. 9 at p. 7;
AHRI, No. 11 at p. 12; National Refrigeration, No 17 at p. 1; Hussmann,
No. 18 at p. 14) National Refrigeration asserted that CO2
tends to be used in large, complex multi-compressor systems and
therefore, would not be used in smaller systems with just one dedicated
condensing unit (National Refrigeration, No. 17 at p. 1) The CA IOUs
stated that CO2 unit coolers cannot be tested and rated at
the temperatures and pressures used in the current test procedure for
more traditional hydrofluorocarbon (``HFC'') refrigerants; however,
single-packaged dedicated CO2 refrigeration systems should
be able to use the test methods established in AHRI 1250-2020 for
single-packaged dedicated systems, because these test methods do not
use refrigerant flow or refrigerant conditions for energy calculations.
(CA IOUs, No. 14 at p. 4) Additionally, the CA IOUs urged DOE to ensure
that the WICF test procedures and metrics continue to provide consumers
with the information necessary to easily compare the
[[Page 23928]]
performance of products with the same utility. Id.
---------------------------------------------------------------------------
\9\ CO2 refrigeration systems are transcritical
because the high-temperature refrigerant that is cooled by ambient
air is in a supercritical state, above the 87.8 [deg]F critical
point temperature, above which the refrigerant cannot exist as
separate vapor and liquid phases.
---------------------------------------------------------------------------
DOE preliminarily finds that, in the North American market,
CO2 is primarily used in large rack systems, and that there
do not appear to be any CO2 dedicated condensing units
available. Hence, DOE tentatively finds that adopting a test procedure
for CO2 dedicated condensing units is currently not
warranted. However, DOE has also tentatively determined that the test
methods in AHRI 1250-2020 for single-packaged dedicated systems do not
need to be modified for CO2 refrigerant as long as these
units are tested using air enthalpy or calorimeter test methods, rather
than a refrigerant enthalpy method. DOE further discusses its proposals
for testing single-packaged dedicated systems in section III.G.2 of
this document.
In this NOPR, DOE is proposing that walk-in refrigeration equipment
utilizing CO2 as a refrigerant meet the definition of a
walk-in refrigeration system, but that the DOE test procedure, as
proposed in this document, would apply only to (1) single-packaged
dedicated systems and (2) unit cooler variants of CO2
refrigeration systems. This proposal would exclude CO2
dedicated condensing units from the proposed test procedure. The test
procedures for CO2 unit coolers and single-packaged
refrigeration systems which use CO2 as a refrigerant are
outlined in more detail in sections III.F.6 and III.G.2.f of this
document, respectively.
c. Multi-Circuit Single-Packaged Refrigeration Systems
DOE has received a request for waiver and interim waiver from
Refrigerated Solutions Group (``RSG'') from the test procedure in
subpart R, appendix C, for basic models of single-packaged dedicated
systems having multiple refrigerant circuits within a single unit that
share a single evaporator and a single condenser. (Docket EERE-2022-BT-
WAV-0010, No. 1) In its petition, RSG stated that the current walk-in
test procedure does not address multiple refrigeration circuits that
are enclosed in a single unit. Id. Therefore, in this test procedure
NOPR, DOE has initially determined that refrigeration systems with
multiple refrigeration circuits that share a single evaporator and a
single condenser and are used in walk-in applications meet the
definition of ``walk-in cooler and walk-in freezer.'' Thus, DOE
proposes to define ``multi-circuit single-packaged dedicated system''
in section III.A.2.e of this document. Additionally, DOE is proposing a
test procedure for such systems.
d. Ducted Units
DOE is aware that some walk-in evaporators and/or dedicated
condensing units are sold with provisions to be installed with duct(s)
to circulate air between the walk-in and the refrigeration system. The
current definition of ``single-packaged dedicated system'' specifies
that such systems do not have ``any element external to the system
imposing resistance to flow of the refrigerated air;'' and the
definition of ``unit cooler'' specifies that such equipment does not
have ``any element external to the cooler imposing air resistance.''
(10 CFR 431.302) As such, unit coolers and single-packaged dedicated
systems sold for ducted installation are not addressed by either
definition--also, the current test procedure does not include
provisions for setup of ductwork. While the definition for condensing
unit does not exclude systems intended for ducted installation, the
current test procedure does not include provisions for setup of
ductwork for these components either.
DOE has granted waivers from the test procedure in subpart R,
appendix C, to Air Innovations, Vinotheque, Cellar Pro, and Vinotemp,
and an interim waiver to LRC Coil, for walk-ins marketed for use as
wine cellar refrigeration systems (see Table III.2). The waivers are
discussed in more detail in sections III.A.2.c and III.G.6 of this
document. Relevant to the present discussion of scope, the specific
basic models for which waivers have been granted include equipment sold
as ducted units. As a result of the test procedure waivers granted by
DOE, DOE proposes to revise the single-packaged dedicated system
definition to clarify that such systems may have provisions for ducted
installation. DOE proposes to add a definition for ``ducted fan coil
unit,'' the ducted equivalent of a unit cooler. In doing so, DOE
preserves the standard industry definition of a unit cooler while
expanding the scope of the test procedure to ducted units. DOE also
proposes to add provisions in the test procedures to address setup of
ductwork and the external static pressure that it imposes on
refrigeration system fans--all in order to improve representativeness
of the test procedure. These test procedure revisions are addressed in
section III.G.6 of this document.
Table III.2--Interim Waivers and Waivers Granted to Manufacturers of
Walk-ins Marketed as Wine Cellar Refrigeration Systems
------------------------------------------------------------------------
Waiver decision
Interim waiver and order Federal
Manufacturer Federal Register Register
citation citation
------------------------------------------------------------------------
Air Innovations................. 86 FR 2403 (Jan. 86 FR 23702 (May
12, 2021). 4, 2021).
Vinotheque...................... 86 FR 11961 (Mar. 86 FR 26504 (May
1, 2021). 14, 2021).
CellarPro....................... 86 FR 11972 (Mar. 86 FR 26496 (May
1, 2021). 14, 2021).
Vinotemp........................ 86 FR 23692 (May 86 FR 36732 (July
4, 2021). 13,2021).
LRC Coil........................ 86 FR 47631 (Aug.
26, 2021).
------------------------------------------------------------------------
2. Definitions
a. Walk-in Cooler and Walk-in Freezer
The term ``walk-in cooler and walk-in freezer'' means an enclosed
storage space refrigerated to temperatures, respectively, above, and at
or below 32 [deg]F, that can be walked into, and has a total chilled
storage area of less than 3,000 square feet; however, the term does not
include products designed and marketed exclusively for medical,
scientific, or research purposes. 10 CFR 431.302. (See also 42 U.S.C.
6311(20))
In this notice, DOE proposes to amend the definition of walk-in
cooler and freezer to specify that a walk-in may be comprised of doors,
panels, and refrigeration systems. As explained in section I.B of this
document, DOE established separate test procedures and energy
conservation standards for the principal components that make up a
walk-in: panels, doors, and refrigeration systems. 76 FR 21580, 21582
and 79 FR 32050, 32051-32052. DOE noted in a final rule published March
7, 2011 (``March 2011 Compliance, Certification, and Enforcement
(``CCE'') final rule'') that the legislative design standards set forth
in EPCA provide the framework for a component-based approach since each
design standard is based on the performance of a given component of the
walk-in. 76 FR 12422, 12444. In order to align the definition with the
regulatory scheme adopted by DOE, DOE proposes to revise the definition
to mean an enclosed storage space, including but not limited to panels,
doors, and refrigeration systems, refrigerated to temperatures,
respectively, above, and at or below 32
[[Page 23929]]
degrees Fahrenheit that can be walked into, and has a total chilled
storage area of less than 3,000 square feet; however, the terms do not
include products designed and marketed exclusively for medical,
scientific, or research purposes. DOE does not intend for this amended
definition to expand the scope of the definition for walk-in coolers
and freezers nor does it intend for this amended definition to expand
the certification and compliance responsibilities of entities involved
in manufacturing or assembling walk-ins or walk-in components. Instead,
DOE's proposed revision to the definition of walk-in cooler and walk-in
freezer clarifies that DOE has the authority to separately regulate
walk-in components as well as a full walk-in system (including but not
limited to panels, doors, and refrigeration systems). The March 2011
CCE final rule adopted a definition for a walk-in manufacturer to
specify the entities responsible for certification and/or compliance of
walk-ins or walk-in components. 76 FR 12422, 12442-12444. DOE
emphasizes that both the component manufacturer and the assembler bear
the responsibility of standards compliance, even though the component
manufacturer is the entity responsible for certification. An assembler
may rely on the certification from the component manufacturer regarding
whether the component being used is certified as compliant with DOE
standards.
Issue 1: DOE requests comment on its proposed changes to the
definition for walk-in cooler and walk-in freezer.
b. Doors
With respect to walk-ins, DOE defines a ``door'' as an assembly
installed in an opening on an interior or exterior wall that is used to
allow access or close off the opening and that is movable in a sliding,
pivoting, hinged, or revolving manner of movement. For walk-in coolers
and walk-in freezers, a door includes the door panel, glass, framing
materials, door plug, mullion, and any other elements that form the
door or part of its connection to the wall. 10 CFR 431.302. In the June
2021 RFI, DOE requested feedback on the current definition of ``door.''
86 FR 32332, 32335.
Hussmann stated that the current definition of door is sufficient.
(Hussmann, No. 18 at p. 3) Anthony and AHRI stated that ``door'' is
unclear and inadequately defined. (Anthony, No. 8 at p. 1; AHRI, No. 11
at p. 2) AHRI commented that the current definition seems to describe
an individual ``door'' opening, but that the requirement for testing
uses the opening space in the walk-in regardless of whether it contains
more than one ``door'' opening. AHRI suggested that the definition of
``door'' should contain the door frame and all door components, and
that DOE should differentiate between the number of openings for a
specific door assembly inserted into the opening space, especially for
display doors. (AHRI, No. 11 at pp. 2-3) Anthony asserted that any
component that is part of the door assembly (e.g., door, frame, wiring)
is within the definition of a WICF door. (Anthony, No. 8 at pp. 1-2)
In the June 2021 RFI, DOE also requested comment specifically on
the use of the term ``door plug'' within the definition of ``door.'' 86
FR 32332, 32335. Anthony and AHRI stated that they were unfamiliar with
the term ``door plug.'' (Anthony, No. 8 at pp. 1-2; AHRI, No. 11 at pp.
2-3) Imperial Brown stated that the door plug is the moving part of the
door that can swing or slide and comes attached to the frame. (Imperial
Brown, No. 15 at p. 1) Hussmann stated that the term ``door plug'' is
in reference to a regular door plug (i.e., plugging heaters from a door
to a frame system), and that Hussmann does not use the term ``door
plug'' interchangeably with a ``door.'' (Hussmann, No. 18 at p. 3)
DOE recognizes that the current definition of ``door'' does not
explicitly address that walk-in door assemblies may contain multiple
door openings within one frame. DOE also notes that NFRC 100 includes
several defined terms relating to door components (e.g., door leaf),
which differ from the terms used in DOE's definition of ``door.''
Additionally, certain stakeholders commented that they are unfamiliar
with the term ``door plug,'' whereas others use it to describe
different components of the door assembly.
DOE proposes to amend the definition of ``door'' to address doors
with multiple openings within one frame; to include terminology that
generally aligns with terminology used by the industry; and to remove
use of the term ``door plug,'' which is being interpreted
inconsistently by stakeholders. Specifically, DOE proposes to amend the
definition of ``door'' to mean an assembly installed in an opening of
an interior or exterior wall that is used to allow access or close off
the opening and that is movable in a sliding, pivoting, hinged or
revolving manner of movement. For walk-in coolers and walk-in freezers,
a door includes the frame (including mullions), the door leaf or
multiple door leaves (including glass) within the frame, and any other
elements that form the assembly or part of its connection to the wall.
DOE also proposes to define the term ``door leaf'' to mean the
pivoting, rolling, sliding, or swinging portion of a door. DOE
tentatively concludes that the proposed revision of ``door'' and
proposed definition of ``door leaf'' better align with industry
terminology and address doors with multiple openings within one frame.
DOE does not intend for the proposed changes to the definition of
``door'' and the newly defined term for ``door leaf'' to change the
scope of applicability of the DOE test procedures or the applicability
of standards for walk-in doors.
As discussed in the June 2021 RFI, DOE differentiates WICF doors by
whether such doors are ``display doors'' or not display doors (i.e.,
``passage doors'' or ``freight doors''). 86 FR 32332, 32335. A
``freight door'' is a door that is not a display door and is equal to
or larger than 4 feet wide and 8 feet tall. 10 CFR 431.302. A ``passage
door'' is a door that is not a freight or display door. Id. The use of
dimensions in the definition of freight door conveys that these doors
typically allow large machines (e.g., forklifts) to pass through
carrying freight. However, the definition does not address instances
where one dimension exceeds the height or width requirement per the
definition, but the other dimension is smaller than the other dimension
requirement per the definition. In some cases, the surface area for
such doors could be larger than 32 square feet, the area of a 4-foot by
8-foot door provided in the definition (e.g., a door 5 feet wide and 7
feet tall, with a surface area of 35 square feet); in other cases, the
surface area could be smaller than 32 square feet (e.g., a door 5 feet
wide and 6 feet tall, with a surface area of 30 square feet). As part
of the June 2021 RFI, DOE reviewed the certified surface areas of
freight and passage doors in DOE's Compliance Certification Management
System (``CCMS'') Database. DOE found that many models certified as
passage doors had rated surface areas greater than or equal to 32
square feet while some models certified as freight doors had rated
surface areas less than 32 square feet. 86 FR 32332, 32335.
In the June 2021 RFI, DOE requested comment on whether height and
width or surface area effectively distinguish between passage and
freight doors and whether there are any building codes, standards, or
industry practices to support or refute maintaining dimensions of a
door as the defining characteristics separating freight and passage
doors. Additionally, DOE sought comment on any other attributes other
than size which would
[[Page 23930]]
appropriately distinguish passage and freight doors. Lastly, DOE sought
comment on how to classify non-display doors with multiple openings
where the individual door openings do not meet the definition of
freight door, but the overall door assembly would meet the definition
of a freight door per the dimension requirements in the freight door
definition. Id.
The CA IOUs generally supported DOE updating its definitions
related to walk-in doors to prevent mis-categorization. Specifically,
the CA IOUs suggested that DOE align with industry definitions for
freight doors, such as vertical or sectional overhead doors, and
consider differentiating doors based on opening characteristics (e.g.,
swing, horizontal slide, vertical slide, rollup) rather than size. (CA
IOUs, No. 14 at p. 5)
Imperial Brown stated that the door width-in-clear \10\ (or
``WIC'') should be the determining factor for distinguishing passage
and freight doors. Imperial Brown recommended that a freight door be
identified as a door with a WIC of 48 inches or more and a height-in-
clear \11\ (``HIC'') of 78 inches or more, allowing for pallet and
forklift traffic. (Imperial Brown, No. 15 at p. 1)
---------------------------------------------------------------------------
\10\ Imperial Brown defined WIC as the clear opening width,
typically from left frame jamb to right frame jamb. (Imperial Brown,
No. 15 at p. 1)
\11\ Imperial Brown defined HIC as the clear opening height,
typically from door sill to frame header. (Imperial Brown, No. 15 at
p. 1)
---------------------------------------------------------------------------
AHRI stated that the current area cut-off of 4 feet by 8 feet is
sufficient for distinguishing between passage and freight doors. AHRI
stated that there are no specific dimensions that distinguish freight
from passage doors and that the dimensions tend to be application
specific. AHRI also commented that generally the height of passage and
freight doors are similar, but that the width varies. (AHRI, No. 11 at
p. 3)
Regarding other characteristics that may distinguish passage and
freight doors, both Anthony and Hussmann stated that they define
passage doors and freight doors by whether the door is provided for
personnel access to the WICF (i.e., passage doors) or provided for
stocking of product with the use of equipment (i.e., freight doors).
(Anthony, No. 8 at p. 2; Hussmann, No. 18 at pp. 3-4) Hussmann stated
that passage doors must be large enough for individuals to pass through
and meet requirements established by the Americans with Disabilities
Act (``ADA''). (Hussmann, No. 18 at pp. 3-4)
Regarding non-display doors that contain multiple openings, AHRI
and Hussmann commented that it is not necessary to change how non-
display doors with multiple openings are classified. (AHRI, No. 11 at
p. 3; Hussmann, No. 10 at p. 4) Imperial Brown stated that non-display
doors with multiple openings should be considered freight doors only if
they have an unobstructed WIC by HIC (i.e., there are no mullions in
the opening) that meets the freight door dimensional requirements.
(Imperial Brown, No. 15 at p. 1)
Considering the comments received, DOE is not proposing to revise
the definition of ``freight door'' at this time.
DOE is proposing to define the term ``non-display door.'' Although
the test procedures outlined in 10 CFR 431.304 and appendices A and B
use the term ``non-display door,'' it is not currently defined. The
proposed definition would provide that a ``non-display door'' would
mean a door that is not a display door.
Based on the input it has received, DOE has tentatively determined
that differentiating walk-in doors based on opening characteristics
would better align with industry terminology. Therefore, DOE is
proposing to define three terms, which include some industry
terminology identified in NFRC 100, to further differentiate among both
display and non-display doors: ``Hinged vertical door,'' ``roll-up
door,'' and ``sliding door'' (see proposed definitions set out in the
regulatory text at the end of the document, proposed Sec. 431.302).
Issue 2: DOE requests feedback on the proposed changes to the
definition of ``door'' and the newly proposed definition for ``door
leaf.'' DOE also seeks comment on the newly proposed definitions for
certain door opening characteristics: ``Hinged vertical door,'' ``roll-
up door,'' and ``sliding door.''
c. High-Temperature Refrigeration Systems
As discussed previously, DOE has granted several manufacturers
waivers and interim waivers from the test procedure in subpart R,
appendix C, for basic models of refrigeration systems marketed as wine
cellar refrigeration systems (see section III.A.1.d). These
manufacturers stated that walk-ins used for wine storage are intended
to operate at a temperature range of 45 to 65 [deg]F and 50-70 percent
relative humidity, rather than the 35 [deg]F and less than 50 percent
relative humidity test condition prescribed in subpart R, appendix C.
In the June 2021 RFI, DOE requested comment on how refrigeration
systems marketed as wine cellar refrigeration systems should be defined
to best represent the conditions under which these systems are designed
to operate. 86 FR 32332, 32334-32335. AHRI, Lennox, and the CA IOUs
recommended that DOE adequately define refrigeration systems marketed
as wine cellar refrigeration systems and evaluate them as a separate
efficiency class. (Lennox, No. 9 at p. 6; AHRI, No. 11 at p. 11; CA
IOUs, No. 14 at pp. 3-4) AHRI and Hussmann suggested that refrigeration
systems marketed as wine cellar refrigeration systems be defined as an
enclosed storage space designed to be cooled to between 45 [deg]F and
65 [deg]F with a relative humidity range of 50 percent to 70 percent,
and typically kept at 55 [deg]F and 55% RH. (AHRI, No. 11 at p. 2;
Hussmann, No. 18 at p. 3) Daikin stated that refrigeration systems
marketed as wine cellar refrigeration systems operate between 37.4
[deg]F and 68 [deg]F, and between 70% and 85% relative humidity.
(Daikin, No. 17 at p. 2)
In the June 2021 RFI, DOE also requested feedback on walk-in
applications other than wine cellar cooling that may have a target room
temperature of 35 [deg]F and higher. 86 FR 32332, 32334-32335. Lennox,
AHRI and Hussmann each stated that wine cellars are the only walk-in
applications with a temperature range between 45 [deg]F and 65 [deg]F
and with a relative humidity between 50 percent and 70 percent.
(Lennox, No. 9 at p. 2; AHRI, No. 11 at p. 2; Hussmann, No. 18 at pp.
2-3) Daikin stated by way of example that florist coolers operate at 68
[deg]F and between 90% to 95% humidity. (Daikin, No. 17 at p. 2)
DOE understands from these comments that there are walk-in
applications other than wine cellars that require cooling to
temperatures higher than 35 [deg]F. To provide for testing of such
walk-ins using test conditions that result in measurements of energy
use in a representative average-use cycle DOE proposes to define walk-
ins designed to operate at cooling temperatures above 45 [deg]F as
employing a ``high-temperature refrigeration system''--which would mean
a walk-in refrigeration system which is not designed to operate below
45 [deg]F.'' The proposed definition would provide for the testing of
such units using specified conditions representative of their average
use, i.e., cooling the refrigerated space to a temperature above 45
[deg]F. See the corresponding test procedure provisions proposed in
section III.G.6 for further details.
d. Ducted Fan Coil Units
DOE has granted waivers to Air Innovations, Vinotheque, Cellar Pro,
and Vinotemp, and an interim waiver to LRC Coil for walk-ins that are
marketed
[[Page 23931]]
as wine cellar refrigeration systems that are designed and marketed as
ducted units. (See Table III.2) The definitions for single-packaged
units and unit coolers currently exclude ducted units, resulting in the
lack of a test procedure for such units. 10 CFR 431.302. Specifically,
the current single-packaged unit definition excludes units with ``any
element external to the system imposing resistance to flow of the
refrigerated air.'' Similarly, the current unit cooler definition
specifically excludes units with ``element[s] external to the cooler
imposing air resistance.'' Id.
In the June 2021 RFI, DOE requested comment on changing the
``single-packaged dedicated system'' and ``unit cooler'' definitions to
address units that are designed to be installed with ducts. 86 FR
32332, 32346. Lennox and AHRI both stated that the ASHRAE 210P
committee \12\ is working to define a ``ducted unit cooler'' and is
currently considering defining it as ``an assembly, including means for
forced air circulation, capable of moving air against both internal and
non-zero external flow resistance, and elements by which heat is
transferred from air to refrigerant to cool the air, with provision for
ducted installation.'' (Lennox, No. 9 at p. 6; AHRI, No. 11 at p. 11)
Lennox and AHRI both urged DOE to work with the ASHRAE 210P committee
to find an appropriate solution. (Lennox, No. 9 at p. 7; AHRI, No. 11
at p. 12)
---------------------------------------------------------------------------
\12\ The American Society of Heating, Refrigerating and Air-
Conditioning Engineers (``ASHRAE'') has formed the ASHRAE Standard
Project Committee 210 (``ASHRAE 210P'') to evaluate and revise its
``Method of Testing and Rating Commercial Walk-in Refrigerators and
Freezers.'' See spc210.ashraepcs.org/.
---------------------------------------------------------------------------
To clarify that refrigeration systems that have provision for
ducted installation are indeed included in the DOE test procedure, DOE
is proposing an appropriate term and a definition for the term ``ducted
unit cooler'' mentioned by commenters and is also proposing to revise
the definition for single-packaged dedicated system to clarify that
such a system can have provision for ducted installation. DOE proposes
to adopt the new term, ``ducted fan-coil unit,'' which would be defined
as an assembly including means for forced air circulation capable of
moving air against both internal and non-zero external flow resistance,
and elements by which heat is transferred from air to refrigerant to
cool the air, with provision for ducted installation. DOE is also
proposing to revise the current single-packaged dedicated system
definition to mean a refrigeration system (as defined in 10 CFR
431.302) that is a single-packaged assembly that includes one or more
compressors, a condenser, a means for forced circulation of
refrigerated air, and elements by which heat is transferred from air to
refrigerant.
Issue 3: DOE requests comment on the proposed definition of
``ducted fan coil unit'' and on the proposed modification to the
``single-packaged dedicated system'' definition.
e. Multi-Circuit Single-Packaged Refrigeration Systems
As discussed in section III.A.1.c, DOE is proposing to include a
test procedure for evaluating the energy consumption of single-packaged
units that contain multiple refrigeration circuits. As discussed, these
units differ from larger multi-circuit refrigeration systems in that
the refrigeration circuits are housed within an assembly and share a
single condenser and a single evaporator. DOE proposes to define a
``multi-circuit single-packaged refrigeration system'' as a single-
packaged dedicated system (as defined in 10 CFR 431.302) that contains
two or more refrigeration circuits that refrigerate a single stream of
circulated air.
Issue 4: DOE requests comment on the proposed definition for multi-
circuit single-packaged dedicated refrigeration systems.
f. Attached Split Systems
DOE is aware of some refrigeration systems that are sold as matched
pairs in which the dedicated condensing unit and unit cooler are
permanently attached to each other with structural beams. When these
units are mounted to the refrigerated box, these beams extend through
the wall of the walk-in, connecting the unit cooler inside the
refrigerated box with the dedicated condensing unit outside the
refrigerated box. The functionality of an attached split system may be
similar to that of a matched pair system but may also have similarities
to a single-packaged dedicated system, since they are single
assemblies. The DOE test procedure does not currently define such
systems, nor does it provide any unique test provisions for them--
thereby affecting the ability of manufacturers to provide test results
reflecting the energy efficiency of this equipment during a
representative average use cycle. DOE discusses its proposal for
testing such units in section III.G.4 of this document. DOE has
initially determined that attached split systems are a type of matched
pair system and proposes to define these systems as matched pair
refrigeration systems designed to be installed with the evaporator
entirely inside the walk-in enclosure and the condenser entirely
outside the walk-in enclosure, and the evaporator and condenser are
permanently connected with structural members extending through the
walk-in wall.
Issue 5: DOE requests comment on the proposed definition for
attached split system.
g. Detachable Single-Packaged System
DOE is aware of some refrigeration systems that are designed to be
installed with the evaporator unit exchanging air through the wall or
ceiling of the walk-in as would be the case in a single-packaged
system, but with the condensing unit installed either next to the
evaporator unit or installed remotely and connected to the evaporator
with refrigerant lines as is done in split systems. The current DOE
test procedure does not define such systems or provide testing
provisions specific to this configuration. DOE discusses its proposal
for testing such units in section III.G.3 of this document. DOE has
initially determined that these units are a type of single-packaged
dedicated system, and proposes to define a detachable single-packaged
system as a system consisting of a dedicated condensing unit and an
insulated evaporator section in which the evaporator section is
designed to be installed external to the walk-in enclosure and
circulating air through the enclosure wall, and the condensing unit is
designed to be installed either attached to the evaporator section or
mounted remotely with a set of refrigerant lines connecting the two
components.
Issue 6: DOE requests comment on the proposed definition for
detachable single-packaged dedicated system.
h. CO2 Unit Coolers
As discussed in section III.A.1.b, DOE is proposing to adopt test
procedures for unit coolers designed for use in CO2
refrigeration systems, these proposals are discussed in detail in
section III.F.6 of this document. CO2 systems are designed
and built to operate using CO2 as a refrigerant, which has
the potential to reach pressures much higher than conventional
refrigerants. With the air enthalpy test method, CO2 single-
packaged refrigeration systems would use the same test methods as
conventional-refrigerant single-packaged dedicated systems (see DOE's
proposal discussed in section III.G.2.f). However, the proposed test
procedure for CO2 unit coolers would alter the inlet
refrigerant test conditions as compared to conventional refrigerants
(see section III.F.6). To clarify the scope
[[Page 23932]]
of the proposed unit cooler test procedure, DOE is proposing to define
a CO2 unit cooler as one that includes a nameplate listing
only CO2 as an approved refrigerant.
Issue 7: DOE requests comment on the proposed definition of
CO2 unit coolers. DOE also requests comment on whether any
distinguishing features of CO2 unit coolers exist that could
reliably be used as an alternative approach that can differentiate them
from those unit coolers intended for use with conventional
refrigerants.
i. Hot Gas Defrost
As discussed previously, DOE published a final rule that amended
the test procedure to rate hot gas defrost unit coolers using the
modified default values for energy use and heat load contributions in
AHRI 1250-2020. 86 FR 16027. At that time, DOE did not adopt a
definition for ``hot gas defrost.'' However, as discussed in more
detail in section III.G.8.b, DOE is proposing that equipment with hot
gas defrost installed at the factory may be marketed using
representations of performance with hot gas defrost activated. This
would be a voluntary representation by the manufacturer. To ensure that
the scope of this voluntary representation is clear, DOE is proposing
to define ``hot gas defrost'' as a factory-installed system where
refrigerant is used to transfer heat from ambient outside air, the
compressor, and/or a thermal storage component that stores heat when
the compressor is running and uses this stored heat to defrost the
evaporator coils.
Issue 8: DOE requests comment on the proposed definition for hot
gas defrost. Specifically, DOE requests comment on if this proposed
definition is sufficient to identify which equipment is sold with hot
gas defrost capability installed and which is not.
B. Industry Standards
The current DOE test procedure for walk-in coolers and freezers
incorporates the following industry test standards: NFRC 100-2010 into
appendix A; ASTM C518 into appendix B; and AHRI 1250-2009, AHRI 420-
2008,\13\ and ASHRAE 23.1-2010 \14\ into subpart R, appendix C. The
following sections detail the industry standards DOE is proposing to
incorporate by reference in the NOPR and the relevant provisions of
those industry standards that DOE is proposing to adopt.
---------------------------------------------------------------------------
\13\ AHRI 420-2008, ``Performance Rating of Forced-Circulation
Free-Delivery Unit Coolers for Refrigeration'' (``AHRI 420-2008'').
\14\ ANSI/ASHRAE 23.1-2010, ``Methods of Testing for Rating the
Performance of Positive Displacement Refrigerant Compressors and
Condensing Units that Operate at Subcritical Temperatures of the
Refrigerant'' (``ASHRAE 23.1-2010'').
---------------------------------------------------------------------------
1. Standards for Determining Thermal Transmittance (U-Factor)
Appendix A references NFRC 100 as the method for determining the U-
factor of doors and display panels. NFRC 100 allows for computational
determination of U-factor by simulating U-factor using Lawrence
Berkeley National Lab's (``LBNL'') WINDOW and THERM software, provided
that the simulated value for the baseline product in a product line is
validated with a physical test of that baseline product and the
simulated value is within the accepted agreement with the physical test
value as specified in section 4.7.1 of NFRC 100.\15\ Section 4.3.2.1 of
NFRC 100 references NFRC 102-2010, ``Procedure for Measuring the Steady
state Thermal Transmittance of Fenestration Systems'' (``NFRC 102-
2010''), as the physical test procedure for determining U-factor. NFRC
102-2010 is based on ASTM C1199-09, ``Standard Test Method for
Measuring the Steady state Thermal Transmittance of Fenestration
Systems Using Hot Box Methods'' (``ASTM C1199-09'') with some
modifications.
---------------------------------------------------------------------------
\15\ Section 4.7.1 of NFRC 100 requires that the accepted
difference between the tested U-factor and the simulated U-factor be
(a) 0.03 Btu/(h-ft\2\-[deg]F) for simulated U-factors that are 0.3
Btu/(h-ft\2\-[deg]F) or less, or (b) 10 percent of the simulated U-
factor for simulated U-factors greater than 0.3 Btu/(h-ft\2\-
[deg]F). This agreement must match for the baseline product in a
product line. Per NFRC 100, the baseline product is the individual
product selected for validation; it is not synonymous with ``basic
model'' as defined in 10 CFR 431.302.
---------------------------------------------------------------------------
Since DOE adopted this test procedure for determining U-factor of
doors and display panels in 2011, NFRC has published updates to NFRC
102, the most recent being NFRC 102-2020, which supersedes all previous
versions of NFRC 102. The following are the identified substantive
changes and additions in NFRC 102-2020 as compared to NFRC 102-2010,
which is referenced in the current Federal test procedure via NFRC 100-
2010:
1. Added a list of required calibrations for primary measurement
equipment, including metering box wall transducer and surround panel
flanking loss characterization and annual verification procedure, and
incorporated a calibration transfer standard (``CTS'') calibration
continuous characterization procedure; and
2. The provisions regarding air velocity distribution were revised
to be more specific to the type of fans used.
Additionally, NFRC 102-2020 references the updated version of ASTM
C1199 (ASTM C1199-14) instead of ASTM C1199-09. Based on a review of
ASTM C1199-14, DOE has tentatively determined that the differences
between editions are editorial.
DOE is proposing to adopt by reference in appendix A, the following
sections of NFRC 102-2020 for determining U-factor:
2. Referenced Documents,
3. Terminology,
5. Apparatus,
6. Calibration,
7. Experimental Procedure (excluding 7.3. Test
Conditions),
8. Calculation of Thermal Transmittance,
9. Calculation of Standardized Thermal Transmittance,
Annex A1. Calibration Transfer Standard Design,
Annex A2. Radiation Heat Transfer Calculation Procedure,
and
Annex A4. Garage Panel and Rolling Door Installation.
DOE is also proposing to incorporate by reference ASTM C1199-14, as
it is referenced in NFRC 102-2020. Specifically, in the proposed test
procedure in appendix A, DOE is proposing to reference the following
sections of ASTM C1199-14 as referenced through NFRC 102-2020: Sections
2, 3, 5, 6, 7 (excluding 7.3), 8, 9, and Annexes A1 and A2. DOE is not
proposing to reference any other sections of NFRC 102-2020 or ASTM
C1199-14 as they either do not apply or they are in direct conflict
with other test procedure provisions included in the subpart R.
2. Standard for Determining R-Value
As mentioned previously, section 4.2 of appendix B references ASTM
C518 to determine the thermal conductivity, or K-factor, of panel
insulation. EPCA requires that the measurement of the K-factor used to
calculate the R-value be based on ASTM C518-2004 (``ASTM C518-04'').
(42 U.S.C. 6314(a)(9)(A)(ii)) In December 2015, ASTM published a
revision of this standard (``ASTM C518-15''). ASTM C518-15 removed
references to ASTM Standard C1363, ``Test Method for Thermal
Performance of Building Materials and Envelope Assemblies by Means of a
Hot Box Apparatus'' (``ASTM C1363''), and added references to ASTM
Standard E456, ``Terminology Relating to Quality and Statistics.''
Additionally, ASTM C518-15 relies solely on the International System of
Units (``SI units''), with paragraph 1.13 clarifying that these SI unit
values are to be regarded as standard. In July 2017, ASTM published
another revision of ASTM C518 (``ASTM C518-17''). ASTM
[[Page 23933]]
C518-17 added a summary of precision statistics from an interlaboratory
study from 2002-2004 in section 10 ``Precision and Bias.''
As part of the June 2021 RFI, DOE requested comment on what issues,
if any, would be present if DOE were to adopt the most current version
of the standard, ASTM C518-17, for measuring panel K-factor. 86 FR
32332, 32336. NFRC stated that the updates to ASTM C518-17 as compared
to what is in ASTM C518-04 would have no substantial impact on the
results of testing and no impact on test burden. NFRC also stated that
adopting ASTM C518-17 would bring DOE test procedures in line with
current industry methods and practice. (NFRC, No. 10 at p. 2) DOE did
not receive any additional comments on potentially adopting ASTM C518-
17 for measuring panel K-factor.
DOE has tentatively determined that the updates to ASTM C518-2004
(the version of the industry test procedure specified by EPCA as the
basis for calculating the K-factor) made in 2015 and 2017 do not
substantively change the test method nor would adoption of the latest
version in the DOE test procedure increase test burden. Therefore, DOE
is proposing to amend its test procedure for determining R-value of
insulation for non-display doors and panels by incorporating by
reference ASTM C518-17. Specifically, in the proposed test procedure in
appendix B, DOE is proposing to reference the following sections of
ASTM C518-17:
2. Referenced Documents,
3. Terminology,
5. Apparatus,
6. Calibration,
7. Test Procedures (excluding 7.3. Specimen Conditioning),
8. Calculation, and
Annex A1. Equipment Design.
DOE is not proposing to reference any other sections of ASTM C518-
17 as they either do not apply or they are in direct conflict with
other test procedure provisions included in subpart R. As ASTM C518-17
is an updated version of ASTM C518-2004, the DOE test procedure for
determining the K-value remains based on ASTM C518-2004.
3. Standards for Determining AWEF
DOE's current test procedure for WICF refrigeration systems is
codified in appendix C to subpart R of part 431 and incorporates by
reference AHRI 1250-2009, AHRI 420-2008, and ASHRAE 23.1-2010. AHRI
1250-2009 is the industry test standard for refrigeration systems for
walk-in coolers and freezers, including unit coolers and dedicated
condensing units sold separately, as well as matched pairs. 81 FR
95758, 95798.\16\ The procedure describes the method for measuring the
refrigeration capacity and the electrical energy consumption for a
condensing unit and a unit cooler, including off-cycle fan and defrost
subsystem contributions. Using the refrigeration capacity and
electrical energy consumption, AHRI 1250-2009 provides a calculation
methodology to compute AWEF, the applicable energy-performance metric
for refrigeration systems.
---------------------------------------------------------------------------
\16\ Available at www.ahrinet.org. AHRI 1250-2009 incorporates
by reference AHRI 420-2008 for testing of unit coolers and ASHRAE
23-2005 for testing of dedicated condensing units. DOE has updated
the reference for the latter test standard to ASHRAE 23.1-2010.
---------------------------------------------------------------------------
The DOE test procedure for walk-in refrigeration systems adopts by
reference the test procedure in AHRI 1250-2009 (excluding Tables 15 and
16), with certain enumerated modifications. Generally, DOE's
modifications to AHRI 1250-2009 address specific test conditions,
tolerances, and instrumentation requirements, as well as specific
instructions for how to address defrost energy use, unit coolers tested
alone, and dedicated condensing units tested alone. See appendix C to
subpart R of part 431.
In 2014, AHRI published an update to AHRI Standard 1250 (``AHRI
1250-2014'') which supersedes AHRI 1250-2009. After publication of AHRI
1250-2014, DOE and other stakeholders supported the AHRI 1250 committee
in its update of AHRI Standard 1250. Subsequently, in April 2020, AHRI
published AHRI 1250-2020, which supersedes AHRI 1250-2014. AHRI 1250-
2020 incorporates many of the modifications and additions to AHRI 1250-
2009 that DOE currently prescribes in its test procedure. It also
includes test methods for unit coolers and dedicated condensing units
tested alone, rather than incorporating by reference updated versions
of AHRI 420-2008 and/or ASHRAE 23.1-2010, and also includes test
methods for single-packaged dedicated systems. Sections III.B.3.a to
III.B.3.d detail the changes made to AHRI 1250-2020 as compared to AHRI
1250-2009.
In the June 2021 RFI, DOE requested comment on what issues, if any,
would be present if DOE were to adopt AHRI 1250-2020 into the DOE test
procedure. 86 FR 32332, 32336. The CA IOUs and NEEA stated their
general support for the adoption of AHRI 1250-2020. (CA IOUs, No. 14 at
p. 1; NEEA, No. 16 at pp. 1-2) Lennox, AHRI, and Hussmann supported the
adoption of AHRI 1250-2020 with some reservations associated with the
retest burden it may create. (Lennox, No. 9 at p. 2; AHRI, No. 11 at p.
4; Hussmann, No. 18 at p. 6) Lennox, AHRI, and Hussmann asked DOE to
evaluate if a full revision of the test standards was appropriate at
this time. (Lennox, No. 9 at p. 2; AHRI, No. 11 at p. 4; Hussmann, No.
18 at p. 6) DOE acknowledges the potential burden of a new test
procedure and notes that a full cost evaluation of the proposed test
procedure changes has been conducted and is discussed in section III.J.
Therefore, DOE is proposing two sets of changes for the refrigeration
system test procedure. One set of changes would be included as proposed
revisions to subpart R, appendix C, and the other group would be
proposed through the establishment of an appendix C1. DOE has
tentatively determined that the changes to subpart R, appendix C, would
not affect AWEF ratings and therefore not require retesting or
recertification. These proposed changes, if adopted, would be required
180 days after the test procedure final rule is published. DOE has also
tentatively determined that the proposed provisions included in
appendix C1 would affect the determination of energy use and would
therefore require retesting and recertification of the proposed AWEF2.
The provisions proposed in appendix C1, if adopted, would be required
to be followed in conjunction with the compliance date of any amended
energy conservation standards that DOE may end up adopting as part of a
separate standards rulemaking.
In this test procedure NOPR DOE is proposing to reference AHRI
1250-2020 for use in appendix C1, but excluding:
Section 1 Purpose,
Section 2 Scope,
Section 9 Minimum Data Requirements for Published Ratings,
Section 10 Marking and Nameplate Data,
Section 11 Conformance Conditions, and
Section C10.2.1.1 Test Room Conditioning Equipment under
section C10--Defrost Calculation and Test Methods.
DOE is not proposing to reference these sections of AHRI 1250-2020
since they either do not apply or conflict with other test procedure
provisions included in the proposed appendix C1. Additionally, DOE is
not proposing to reference ASHRAE 23.1-2010 or AHRI 420-2008 in the
proposed appendix C1, as the materials referenced in these standards by
AHRI 1250-2009 are now included within AHRI 1250-2020.
[[Page 23934]]
Further, DOE is proposing to reference ASHRAE 16-2016 in the
proposed appendix C1, as it is referenced in AHRI 1250-2020, but
excluding:
Section 1 Purpose
Section 2 Scope
Section 4 Classifications
Normative Appendices E-M
Informative Appendices N-R
DOE is not proposing to reference these sections of ASHRAE 16-2016
as they either do not apply or conflict with other test procedure
provisions that would be included as part of the newly proposed
appendix C1.
Similarly, DOE is proposing to reference ASHRAE 37-2009 in the
proposed appendix C1, as it is referenced in AHRI 1250-2020, but
excluding:
Section 1 Purpose,
Section 2 Scope,
Section 4 Classifications,
Informative appendix A Classifications of Unitary Air-
conditioners and Heat Pumps.
DOE is not proposing to reference these sections of ASHRAE 37-2009
as they either do not apply or conflict with other test procedure
provisions that would be included as part of the newly proposed
appendix C1.
a. Changes Consistent With Subpart R, Appendix C
As mentioned previously, AHRI 1250-2020 incorporates many of the
modifications and additions to AHRI 1250-2009 that DOE currently
prescribes in its test procedure. The modifications in the following
sections of subpart R, appendix C, were incorporated into AHRI 1250-
2020. Thus, if DOE were to adopt AHRI 1250-2020, DOE would remove the
following sections from subpart R, appendix C:
Section 3.1.1, which modifies Table 1 (Instrumentation
Accuracy) in AHRI 1250-2009;
Section 3.1.2, which provides guidance on electrical power
frequency tolerances;
Section 3.1.3, which states that in Table 2 of AHRI 1250-
2009, the test operating tolerances and test condition tolerances for
air leaving temperatures shall be deleted;
Section 3.1.4, which states that in Tables 2 through 14 in
AHRI-1250-2009, the test condition outdoor wet bulb temperature
requirement and its associated tolerance apply only to units with
evaporative cooling;
Section 3.1.5, which provides tables to use in place of
AHRI 1250-2009 Tables 15 and 16, which are excluded from the IBR in 10
CFR 431.303. The update in AHRI 1250-2020 to Tables 15 and 16 would
allow DOE to incorporate the AHRI 1250-2020 tables by reference if DOE
were to adopt AHRI 1250-2020;
Section 3.2.1, which provides specific guidance on how to
measure refrigerant temperature;
Section 3.2.2, which removes the requirement to perform a
refrigerant composition and oil concentration analysis;
Section 3.2.4, which provides voltage requirements for
unit cooler fan power measurements;
Section 3.2.5, which provides insulation and configuration
requirements for liquid and suction lines used for testing;
Section 3.3.1, which gives direction for how to test and
rate unit coolers tested alone;
Section 3.3.2, which clarifies that the 2008 version of
AHRI Standard 420 should be used for unit coolers tested alone;
Section 3.3.3, which modifies the allowable reduction in
fan speed for off-cycle evaporator testing;
Section 3.4.1, which specifies that the 2010 version of
ASHRAE 23.1 should be used and that ``suction A'' condition test points
should be used when testing dedicated condensing units and,
Section 3.5, which provides guidance on how to rate
refrigeration systems with hot gas defrost.
The entirety of section 3.4.2 of subpart R, appendix C, which
provides instruction on how to calculate AWEF and net capacity for
dedicated condensing units, would also be removed if AHRI 1250-2020
were to be adopted, but the text in AHRI 1250-2020 that would replace
it alters the text currently in section 3.4.2, which would result in a
change to the current test procedure.
b. CFR Language Not Adopted in AHRI 1250-2020
As mentioned previously, AHRI 1250-2020 incorporates many, but not
all, of the modifications and additions to AHRI 1250-2009 that DOE
currently prescribes in its test procedure. For example, section 3.2.3,
which modifies the requirements in Section C3.4.5 of AHRI 1250-2009 to
require only a sight glass and a temperature sensor located on the tube
surface under the insulation to verify sub-cooling downstream of mass
flow meters, was not incorporated into AHRI 1250-2020. DOE is
proposing, however, to carry over this section into the newly proposed
appendix C1.
With respect to other current sections in subpart R, appendix C,
sections that were not adopted by AHRI 1250-2020, DOE is proposing to
revise those sections as part of this NOPR in the following manner:
Sections 3.3.4 and 3.3.5, which modify the defrost test
procedure in AHRI 1250-2009, would not be carried over into the newly
proposed appendix C1. This NOPR proposes a revised approach to account
for defrost heat load and energy use. This topic and DOE's proposals
are discussed in sections III.G.8.a and III.G.8.b; and
Section 3.3.7, which provides guidance on how to rate
refrigeration systems with variable-speed evaporator fans would also
not be carried over into the newly proposed appendix C1.
c. Changes That May Impact the Determination of AWEF
Several changes in AHRI 1250-2020 may impact the AWEF calculation.
These changes can be grouped into five categories, discussed in the
following paragraphs: Off-cycle tests, single-packaged dedicated
systems, defrost calculations, variable capacity, and unit coolers.
Off-Cycle Tests
AHRI 1250-2020 updated the off-cycle tests in Sections C3.5 and
C4.2 such that the total input wattage of the test unit is measured
during the off cycle, rather than just the unit cooler fan input
wattage. This change accounts for ancillary power from components such
as crank case heaters and would deliver more representative off-cycle
power results. As a result, if DOE were to incorporate this provision
into its test procedure, it would affect the AWEF measurement for
dedicated condensing units, matched pairs, and single-packaged
dedicated systems by accounting for additional energy usage in the
measured off-cycle power consumption value. In addition, updates made
in AHRI 1250-2020 require that the measurement of unit cooler off-cycle
power include the total electric power input to pan heaters and
controls as well as the fan motors. AHRI 1250-2020 requires that off-
cycle fan speed be at least 50% of full speed or that duty cycle for
cycling fans be at least 50%, consistent with the current requirements
of section 3.3.3 of subpart appendix C.
Single-Packaged Units
AHRI 1250-2020 added Section C9.1, which includes test methods for
single-packaged refrigeration units. These methods allow for testing of
single-packaged units with indoor and outdoor air enthalpy methods as
specified in ASHRAE 37 and ASHRAE 16. These methods account for the
heat leakage
[[Page 23935]]
that single-packaged dedicated systems are prone to experience by
design. The inclusion of this heat leakage would lower single-packaged
dedicated systems' net capacities and therefore lower their AWEFs. It
would also make their net capacities more representative of field
performance.
Defrost Calculations
AHRI 1250-2020 combined the defrost calculations and test methods
into Section C10 to AHRI 1250-2020. For systems using electric defrost,
the defrost calculations for defrost heat contributed to the box load
(QDF) have been changed to three different equations
depending on the system's gross capacity. In addition, new calculation
methods for estimating the defrost energy of units with hot gas defrost
have been added. The new default equations for electric and hot gas
defrost heat and energy contributions are based on testing and analysis
work conducted by AHRI and DOE, and therefore these values are expected
to be more representative than previous equations for the default
values.
AHRI 1250-2020 also added two optional challenge \17\ tests for
adaptive and hot gas defrost in appendices E and F, respectively. Both
tests evaluate whether a unit has a system that functions as either an
adaptive or hot gas defrost system. For compliance purposes, DOE
requires that units are tested without activating adaptive defrost or
hot gas defrost; therefore, neither challenge test included in AHRI
1250-2020 would affect the calculation of AWEF. The defrost challenge
tests and calculations are discussed in detail in sections III.G.8.a,
and III.G.8.b of this document.
---------------------------------------------------------------------------
\17\ The defrost challenge tests included in AHRI 1250-2020 are
informative test methods that provide validation that defrost is
occurring as would be expected in Appendix E for adaptive defrost
control systems and in Appendix F for hot gas defrost systems.
Neither challenge test is designed to quantify the energy use of the
defrost system, but are intended to validate defrost system
functionality.
---------------------------------------------------------------------------
d. Additional Amendments
In addition to those changes enumerated in sections III.B.3.a
through III.B.3.c of this document, AHRI 1250-2020 includes additional
amendments that are inconsistent with the current DOE test procedure
and would not be expected to impact calculated AWEF. This section
discusses those changes.
AHRI 1250-2020 added exclusions for liquid-cooled condensing
systems in section 2.2.4. and excludes systems that use carbon dioxide,
glycol, or ammonia as refrigerants in section 2.2.5. The current DOE
test procedure is neutral with respect to refrigerant, and DOE
considers all walk-in refrigeration systems to be covered equipment
regardless of the refrigerant used. However, DOE recognizes that
modifications may be necessary to the test method for different
refrigerants (for example, see discussion in section III.F.6 for
CO2).
As discussed in section III.B.3.a, AHRI 1250-2020 updated many of
the tolerances in Table 2 of section 4. Some of these updates are not
included in the current CFR language. DOE proposes to adopt the
tolerances in AHRI 1250-2020, Table 2 of section 4 in subpart R,
appendix C. As discussed later, DOE expects that the updated tolerance
values would improve the repeatability of the test procedure with no
impact on test cost.
AHRI 1250-2020 includes an updated list of references and the
applicable versions of certain test standards in appendix A,
``References--Normative.'' DOE proposes to reference AHRI 1250-2020
appendix A in subpart R, appendix C. DOE expects that this modification
would have no impact on test cost, while ensuring that more recent test
standards are referenced.
Both AHRI 1250-2009 appendix C and AHRI 1250-2020 appendix C
provide specific test methods for testing walk-in cooler and freezer
systems, whereas the body of the standard specifies test requirements
and calculations for walk-in box load and for determining AWEF.
Additionally, AHRI 1250-2020 includes the following updated provisions:
Section C3 of AHRI 1250-2009 lists requirements for measuring
temperature (Section C3.1), measuring pressure (Section C3.2),
measuring refrigerant properties (Section C3.3), determining
refrigerant flow (Section C3.4), determining unit cooler fan power
(Section C3.5), and specifies measurement and recording intervals
(Section C3.6). In AHRI 1250-2020, Section C3 has been expanded to
include requirements for measuring off-cycle power (Section C3.5) and
determining steady state refrigeration capacity and energy consumption
(Section C3.6), which are applicable to all tests unless otherwise
specified. Aside from single-packaged dedicated system tests and the
off-cycle power tests discussed in the previous section and in Sections
III.G.2 and III.G.1, respectively, of this document, DOE does not
expect that the revisions made to Section C3 in AHRI 1250-2020 would
impact test duration and is therefore proposing to incorporate these
sections (except for Section C3.5) \18\ into subpart R, appendix C.
---------------------------------------------------------------------------
\18\ DOE is proposing to incorporate Section C3.5 of AHRI 1250-
2020 appendix C as a part of the new appendix C1.
---------------------------------------------------------------------------
Sections C3.1.3.1, C3.1.3.2, and C3.1.3.3 of AHRI 1250-2020
specified refrigerant temperature measurement locations for unit
coolers tested alone, matched pairs, and dedicated condensing systems
tested alone. Specific changes include:
For unit coolers tested alone: Refrigerant entering
temperature is measured within six pipe diameters upstream of the
control device (Section C3.1.3.1).
For matched pairs, but not single-packaged dedicated
systems: Refrigerant entering temperature is measured within the first
six inches of the refrigerant pipe entering the unit cooler conditioned
space, and the leaving temperature is measured within the last six
inches of the refrigerant pipe leaving the unit cooler conditioned
space (Section C3.1.3.2); and
For dedicated condensing units tested alone: Entering and
leaving refrigerant temperatures are measured at the inlet and outlet
of the unit using two independent measuring systems (Section C3.1.3.3).
The modifications for measuring refrigerant temperature in AHRI
1250-2020 are expected to improve the repeatability and reproducibility
of the test procedure, but do not impact test setup or test duration;
therefore, DOE is proposing to reference these sections in subpart R,
appendix C.
AHRI 1250-2020 added Section C7.5.1.1 to provide more detailed
instructions for calculating system capacity beginning with measured
temperatures instead of calculated enthalpies, which is what was done
in AHRI 1250-2009. Section C7.5.1 also includes the determination of
enthalpy from capacity test results.
AHRI 1250-2020 added Section C9.2, which specifies an allowable
heat balance of 6 percent for single-packaged
refrigeration capacity testing. AHRI 1250-2009 required a heat balance
of 5 percent for all systems. This change was made to
align with ASHRAE 37, which AHRI 1250-2020 incorporates by reference
for single-packaged testing.
AHRI 1250-2009 included Section C12 ``Method of Testing Condensing
Units for Walk-In Cooler and Freezer Systems for Use in Mix-Match
System Ratings,'' which referenced AHRAE 23.1-2010. AHRI 1250-2020 now
provides specific test methods for testing dedicated condensing units
[[Page 23936]]
tested alone. DOE has tentatively determined that the test procedure
incorporated into AHRI 1250-2020 is the same as that in ASHRAE 23.1-
2010 and therefore does not impact test setup or burden. As a result,
DOE proposes to no longer incorporate ASHRAE 23.1-2010 by reference.
Section C13 of AHRI 1250-2009, ``Method of Testing Unit Coolers for
Walk-In Cooler and Freezer Systems for Use in Mix-Match System
Ratings,'' referenced AHRI 420-2008. AHRI 1250-2020 no longer
references AHRI 420-2008 and instead outlines a method for unit coolers
tested alone. As a result, DOE proposes to no longer incorporate AHRI
420-2008 by reference. DOE has tentatively determined that the test
procedure incorporated into AHRI 1250-2020 is the same as that in
ASHRAE AHRI 420-2008 and therefore does not impact test setup or
burden. As a result, DOE proposes to no longer incorporate AHRI 420-
2008 by reference.
C. Proposed Amendments to the Test Procedure in Appendix A for
Measuring the Energy Consumption of Walk-in Doors
Appendix A provides the test procedures to measure the energy
consumption of the components of envelopes of walk-ins. Specifically,
appendix A provides the test procedures to determine the U-factor,
conduction load, and energy use of walk-in display panels and to
determine the energy use of walk-in display doors and non-display
doors. DOE notes that display panels are also subject to the energy
consumption test procedure in appendix A. Display panels are discussed
in section III.D of this document.
In this NOPR, DOE is proposing to make the following revisions to
appendix A, specific to display doors and non-display doors: (1)
Reference NFRC 102-2020 in place of NFRC 100 and adopt AEDM provisions;
(2) provide further detail on and distinguish the area to be used for
determining compliance with standards and the area used to calculate a
thermal load from U-factor; (3) establish a percent time off value
specific to door motors; and (4) reorganize the test method so that it
is easier to follow. The organizational changes include moving the test
methods and measurement provisions for determining U-factor up before
the provisions for calculating energy consumption and moving the
percent time off values for all electrical components into a table. DOE
has preliminarily determined that these changes would improve test
representativeness and repeatability.
DOE does not expect that the changes it is proposing in this
section would have a substantive impact on energy consumption
calculations for display doors or non-display doors, except in the case
of testing doors with motors as described in the following paragraphs.
The following sections describe the modifications that DOE is
proposing to appendix A with respect to walk-in display doors and walk-
in non-display doors.
1. Procedure for Determining Thermal Transmittance (U-Factor)
a. Reference to NFRC 102 in Place of NFRC 100
As discussed in section III.B.1 of this document, section 5.3 of
appendix A requires manufacturers to determine thermal transmittance,
or ``U-factor,'' according to NFRC 100. As also mentioned previously,
NFRC 100 includes a computational method for determining U-factor,
which involves simulating the U-factor using LBNL's WINDOW and THERM
software. Section 4.1.1 of NFRC 100 provides validation requirements so
that simulation, rather than a physical test, can be used for rating U-
factor for a product line. This approach may be less costly but can
result in a different, and potentially less accurate, thermal
transmittance value than the thermal transmittance value determined by
physical test using NFRC 102. NFRC 100 defines a ``product line'' as a
series of individual products of the same product type, and a ``product
type'' as a designation used to differentiate between fenestration
products based on fixed and operable sash and frame members. Section
4.2.1 of NFRC 100 lists the allowable changes from product to product
within a product line. DOE notes that ``product line'' is not
synonymous with ``basic model'' as defined in 10 CFR 431.302. DOE
understands that simulated U-factors of non-display doors using NFRC
100 have generally not been accurately determined when compared to a
physical test.
In the June 2021 RFI, DOE noted it was considering incorporating by
reference NFRC 102 as the test method for determining U-factor of walk-
in doors in place of NFRC 100 and adopting AEDM provisions for walk-in
doors to replace the computational methodology in NFRC 100. 86 FR
32332, 32336. As part of the June 2021 RFI, DOE requested comment on
the accuracy of the computational method in NFRC 100 to predict U-
factor for display and non-display doors, the magnitude of the
difference in U-factor determined using the computational method and
using the physical test method, and whether the computational method
could be modified to more closely match the results obtained from
physical testing. DOE also sought comment on whether manufacturers are
using the computational method in NFRC 100 to rate U-factors, whether
there are other alternative methods for computationally determining U-
factor, and the costs associated with NFRC 100 or other computational
methods compared to physical testing. 86 FR 32332, 32336.
NFRC stated that the NFRC 100 computational method has been used to
accurately simulate U-factors for display doors because the physical
characteristics of a display door are similar to the windows and glass
doors for which the NFRC 100 computational method was developed. NFRC
also stated, however, that there has been limited success validating
NFRC 100 simulations with physical tests for non-display doors because
non-display doors, unlike windows and glass doors, have high amounts of
insulation and significant thermal bypasses along the door perimeter.
(NFRC, No. 10 at p. 1) Similarly, AHRI commented that while NFRC 100 is
appropriate and accurate for display doors, it was not designed for
non-display doors, but it is not aware of an industry test method
better suited for non-display doors. (AHRI, No. 11 at p. 4) NFRC stated
that while refinements to the computational method in NFRC 100 may be
possible for more accurately determining U-factor of non-display doors,
they have not yet been addressed due to limited usage of this method
for specimens like non-display doors. NFRC also stated that the
computational method does not always result in higher or more
conservative U-factors than the U-factors determined through physical
test, and that the test and simulation agreement vary in either
direction. (NFRC, No. 10 at p. 1)
Anthony and Hussmann stated that in their experience, the U-factors
generated using the computational method in NFRC 100 generally align
with the U-factors obtained from the physical test method, NFRC 102.
(Anthony, No. 8 at p. 2; Hussmann, No. 18 at p. 5) Imperial Brown
stated that it is possible to simulate U-factor of non-display doors if
the door frame is included in the simulation and provided example
simulation cross-sections. (Imperial Brown, No. 15 at p. 2)
The CA IOUs recommended that the physical test method ASTM C1199 be
[[Page 23937]]
used for doors and window assemblies to provide a measured approach
that can be compared to the current calculated method. (CA IOUs, No. 14
at p. 5) Hussmann recommended using the computational method
exclusively, except for the physical testing of one model per product
line required for validation, stating that physical testing imposes an
unnecessary burden on a manufacturer. (Hussmann, No. 18 at p. 5)
Imperial Brown asserted that NFRC 102 is costly and time consuming to
conduct, and that it is unrealistic to test all of the models they
offer since the walk-in door market is highly customizable. Imperial
Brown supported continuing to use NFRC 100 and recommended a ``safety
factor'' be included to make up for potential inaccuracies of the
computational method. (Imperial Brown, No. 15 at pp. 1-2)
Anthony urged DOE to eliminate the requirement for a physical test,
stating that there is no added value for it and that physical testing
is more than two times the cost of the computational method. Anthony
also stated, however, that if NFRC 100 remains the referenced industry
test method, the test procedure should specify a course of action if
the computational method results fall outside the 10 percent acceptance
criteria. (Anthony, No. 8 at p. 2)
NFRC stated that developing an AEDM would be inefficient as the
computational method described in NFRC 100 has been shown to be
accurate. (NFRC, No. 10 at p. 1) Additionally, NFRC estimated a cost of
$2,000 for simulating U-factors for a typical product line of display
doors (about 35-50 U-factor values). NFRC emphasized that there is no
economy of scale in performing more physical tests because each sample
must be tested on its own and requires its own specific setup and time
to run. NFRC suggested that given the U-factors of non-display doors
cannot typically be simulated within the agreement specified by NFRC
100, the most economical way to determine U-factor for a product line
would be to pick a few sizes within the range of offerings and use the
worst-case U-factors to represent a range of sizes. (Id. At p. 2)
In response to comments received on the accuracy of the
computational method, DOE understands that there has been limited
success in accurately simulating the U-factor of non-display doors
using NFRC 100. Although stakeholders asserted that NFRC 100 can
accurately simulate display door U-factors, the recommendation by one
stakeholder that instruction be provided when the simulated value and
tested value do not agree within the limits specified by NFRC 100
suggests there may be instances when the computational method does not
provide sufficiently accurate results. DOE recognizes that if display
or non-display door manufacturers are unable to simulate U-factor using
NFRC 100, they are currently required to physically test every door
basic model, which may be unduly burdensome given the highly
customizable nature of the market and thus high number of basic models
to test.
In this NOPR, DOE is proposing to remove reference to NFRC 100 from
its test procedure and instead reference NFRC 102 and adopt provisions
allowing manufacturers to use an AEDM. DOE emphasizes that allowing use
of an AEDM would provide manufacturers with the flexibility to use an
alternative method that yields the best agreement with a physical test
for their doors. If manufacturers have had success using the
computational method in NFRC 100, inclusion of AEDM provisions would
enable manufacturers to continue using NFRC 100, provided that
manufacturers meet the proposed AEDM requirements in 10 CFR 429.53 and
10 CFR 429.70(f). Particularly, under the proposals, manufacturers
would need to ensure that the output result of energy consumption from
the AEDM is within the proposed 5 percent tolerance of an energy
consumption result that includes a physical U-factor test. The proposed
adoption of an AEDM is discussed in more detail in section III.H.1.
b. Exceptions to Industry Test Method for Determining U-Factor
Section 5.3 of appendix A references NFRC 100 for determining U-
factor with the specific modifications to the industry standard listed
in section 5.3(a). The first modification specifies that the average
surface heat transfer coefficients during a test must be within 5 percent of the values specified through NFRC 100 in ASTM
C1199. The second and third items modify the cold and warm side
conditions from the standard conditions prescribed in NFRC 100. The
final provision listed specifies the direct solar irradiance \19\ be 0
Btu/(h-ft\2\).
---------------------------------------------------------------------------
\19\ Solar irradiance is the power per unit area received from
the sun in the form of electromagnetic radiation.
---------------------------------------------------------------------------
As discussed in the June 2021 RFI, DOE has found that obtaining the
standardized heat transfer values within the tolerances specified in
section 5.3(a)(1) of appendix A on the warm-side and cold-side may not
be achievable depending on the thermal transmittance through the door.
86 FR 32332, 32340. Specifically, the warm-side heat transfer is
dominated by natural convection and radiation and the heat transfer
coefficient varies as a function of surface temperature. When testing
doors with higher thermal resistance, less heat is transferred across
the door from the warm-side to the cold-side, so the warm-side surface
temperature is closer to the warm-side air temperature.
Sections 6.2.3 and 6.2.4 of ASTM C1199 specify the standardized
heat transfer coefficients and their tolerances as part of the
procedure to set the surface heat transfer conditions of the test
facility using the Calibration Transfer Standard (``CTS'') test. The
warm-side surface heat transfer coefficient must be within
5 percent of the standardized warm-side value of 1.36 Btu/(h-ft\2\-
[deg]F), and the cold-side surface heat transfer coefficient must be
within 10 percent of the standardized cold-side value of
5.3 Btu/(h-ft\2\-[deg]F) during the CTS test (ASTM C1199, Sections
6.2.3 and 6.2.4). ASTM C1199 does not require that the measured surface
heat transfer coefficients match or be within a certain tolerance of
standardized values during the official sample test--although test
facility operational (e.g., cold side fan settings) conditions would
remain identical to those set during the CTS test. ASTM C1199 also does
not require measurement of the warm-side surface temperature of the
door. Rather, this value is calculated based on the radiative and
convective heat flows from the test specimen's surface to the
surroundings, which are driven by values determined from the
calibration of the hot box using the CTS test (e.g., the convection
coefficient). See ASTM C1199, Section 9.2.1. When testing doors with
extremely high- or low-thermal resistance, the resulting change in
warm-side surface temperature can shift the warm-side heat transfer
coefficient out of the tolerance specified in the DOE test procedure.
To ensure that these coefficients are within tolerance during the test
would require recalibration of the hot box for each specific door.
As part of the June 2021 RFI, DOE requested feedback on the
tolerances currently specified in section 5.3(a)(1) of appendix A
applied to the surface heat transfer coefficients used to measure
thermal transmittance and whether they should be increased or omitted.
86 FR 32332, 32340.
In response, NFRC asserted that applying the surface heat transfer
coefficient tolerances to the surface heat
[[Page 23938]]
transfer coefficients determined in the actual U-factor test is not a
correct application of the NFRC 102 test method and recommended that
the tolerances be removed from section 5.3(a)(1) of appendix A. NFRC
additionally stated that the idea behind the CTS calibration tests is
to set up a consistent set of fan speeds on both sides of the chamber
or to create consistent cold and warm side environments for testing of
all products. NFRC further stated that the convection currents will be
influenced during sample testing by the surface temperatures of the
test sample and that this is an expected and natural occurrence. (NFRC,
No. 10 at pp. 3-4)
Given DOE's experience with testing walk-in doors and the comments
provided by NFRC, DOE is proposing to remove the requirement listed in
section 5.3(a)(1) regarding the surface heat transfer coefficients and
the tolerances on them during testing.
Additionally, while DOE did not request specific comment on the
surface heat transfer coefficients themselves (i.e., the warm side
value of 1.36 Btu/(h-ft\2\-[deg]F) and cold side value of 5.3 Btu/(h-
ft\2\-[deg]F)), Anthony commented that the heat transfer coefficient
applied to the cold side of the test specimen correlates to a wind
speed roughly equivalent to 12.3 miles per hour (``mph''). Anthony
stated that their field testing has demonstrated that the wind speed
interior to the walk-in is below 5 mph. (Anthony, No. 8 at pp. 3-4)
DOE is not proposing to deviate from the surface heat transfer
coefficients specified in NFRC 102-2020 for calibration because
additional investigation is needed. Deviating from these surface heat
transfer coefficients would require test labs to change their test
chamber calibration procedures and would require manufacturers to
retest and re-rate all envelope components subject to the energy
consumption test procedure in appendix A. DOE may consider changes to
the surface heat transfer coefficients specified in NFRC 102-2020 for
calibration in the future if more data became available regarding the
internal and external conditions of walk-ins in various installations.
At this time however, more data and Departmental analysis would need to
be conducted to support any changes to the surface heat transfer
coefficients specified in NFRC 102-2020.
DOE also received comment on the direct solar irradiance
requirement. NFRC stated that direct solar irradiance of 0 Btu/(h-
ft\2\) listed in section 5.3(a)(4) of appendix A is not an exception to
NFRC 100 and should be removed from appendix A. (NFRC, No. 10 at p. 4)
Consistent with DOE's proposal to remove reference to NFRC 100, DOE
proposes to remove this requirement in section 5.3(a)(4) of appendix A.
c. Calibration of Hot Box for Measuring U-Factor
As stated previously, NFRC 100 references NFRC 102 as the physical
test method for measuring U-factor, which in turn incorporates by
reference ASTM C1199. ASTM C1199 references ASTM C1363-05, ``Standard
Test Method for Thermal Performance of Building Materials and Envelope
Assemblies by Means of a Hot Box Apparatus'' (``ASTM C1363''). Section
6.1 of ASTM C1199 and Annexes 5 and 6 of ASTM C1363 include calibration
requirements to characterize metering box wall loss and surround panel
flanking loss, but the frequency at which these calibrations should
occur is not specified in these test standards. As part of the June
2021 RFI, DOE sought comment on the frequency at which test
laboratories perform each of the calibration procedures referenced in
ASTM C1199 and ASTM C1363, e.g., those used to determine the
calibration coefficients for calculating metering box wall loss and
surround panel flanking loss. 86 FR 32332, 32340. DOE also requested
comment on the magnitude of variation in the calibration coefficients
measured during successive calibrations. Id.
NFRC stated that because the referenced ASTM standards (i.e., ASTM
C1199 and ASTM C1363) do not specify frequency of calibration, NFRC 102
includes calibration frequency requirements in section 6.1. NFRC stated
that section 6.1 requires that metering box wall loss and surround
panel flanking loss be determined once and verified annually as these
values would not inherently change over time. It noted that the
verification of the metering box wall loss and surround panel flanking
loss requires results to be within 2 Watts of previous characterization
results. NFRC added that their experience shows that these results
repeat well over time and that an increase in calibration frequency is
unnecessary. (NFRC, No. 10 at p. 3)
As NFRC stated, the most recent version of NFRC 102, NFRC 102-2020,
includes calibration frequencies and requirements in section 6.1(A).
The currently referenced version of NFRC 102, NFRC 102-2010, does not
include these calibration requirements. For this reason and because of
the comments provided by NFRC, DOE is proposing to adopt the
calibration requirements in Section 6.1(A) of NFRC 102-2020.
2. Additional Definitions
a. Surface Area for Determining Compliance With Standards
The surface area of display doors and non-display doors (designated
as Add and And, respectively) are used to determine maximum energy
consumption (``MEC'') in kWh/day of a walk-in door. 10 CFR 431.306(c)-
(d). Surface area is currently defined in section 3.4 of appendix A as
``the area of the surface of the walk-in component that would be
external to the walk-in cooler or walk-in freezer as appropriate.'' As
currently written, the definition does not provide further detail on
how to determine the boundaries of the walk-in door from which height
and width are determined to calculate surface area. Additionally, the
definition does not specify if these measurements are to be strictly
in-plane with the surface of the wall or panel that the walk-in door
would be affixed to, or if troughs and other design features on the
exterior surface of the walk-in door should be included in the measured
surface area. Inconsistent determination of surface area, specifically
with respect to the measurement boundaries, may result in
unrepresentative and inconsistent MEC values. Additionally, walk-in
doors with antisweat heaters are subject to prescriptive standards for
power use of antisweat heaters per square foot of door opening. 10 CFR
431.306(b)(3)-(4). DOE considers the area of the ``door opening'' to be
consistent with the surface area used to determine MEC.
Display doors are fundamentally different from non-display doors in
terms of their overall construction. For example, display door
assemblies contain a larger frame that can encompass multiple door
openings or leaves, and the entire assembly fits into an opening within
a walk-in wall. Non-display doors differ in that they often are affixed
to a panel-like structure that more closely resembles a walk-in wall
rather than a traditional door frame.
In the June 2021 RFI, DOE described how it applies the current test
procedure definition for surface area when determining compliance with
standards. 86 FR 32332, 32337. As part of the June 2021 RFI, DOE
requested comment on how manufacturers determine surface area for the
purpose of evaluating compliance with the MEC performance standards and
with the prescriptive standards pertaining to antisweat heaters for
both display and non-display doors. Id.
AHRI and Hussmann stated that they determine surface area
consistent with DOE, and that they do not see any
[[Page 23939]]
distinctions between display doors and non-display doors that warrant
determining surface area differently. (AHRI, No. 11 at p. 7; Hussmann,
No. 18 at p. 9) Anthony stated that they include the frame and frame
flange as part of the door assembly when determining door surface area.
Anthony also stated that, contrary to how they determine surface area,
Figure 4-2 of NFRC 100-2017 excludes frame flanges. (Anthony, No. 8 at
pp. 2-3) Imperial Brown stated that the area for non-display doors,
And, should be the clear opening area, or WIC by HIC, which excludes
the door frame portion of the door assembly. They also stated that the
clear opening area may be smaller than the swinging or sliding portion
of the door, which typically overlaps a portion of the door frame.
(Imperial Brown, No. 15 at p. 2)
With regard to the prescriptive anti-sweat heater standards,
Anthony agreed that the power use of anti-sweat heat per square foot is
consistent with the surface area used to determine MEC. (Anthony, No. 8
at pp. 2-3) AHRI and Hussmann stated that they do not see a need to
change requirements for the prescriptive standards pertaining to anti-
sweat heaters. (AHRI, No. 11 at p. 7; Hussmann, No. 18 at p. 9)
In response to comments received, DOE notes that the description of
surface area for determining MEC in the June 2021 RFI considers the
structural differences between display and non-display doors and
assumes different bounds for determining the surface area of display
doors and non-display doors. As described previously, DOE includes the
frame in the surface area calculation for display doors, whereas the
panel-like frame of non-display doors has not been included in the
surface area calculation. However, DOE has observed that many
electrical components of non-display doors are sited on or within the
frame to which the door is attached. If the non-display door frame is
not considered as part of the non-display door, the frame would fall
under the category of a walk-in panel. However, the current test
procedure for panels does not account for electrical energy
consumption. Many of the electrical components sited on the non-display
door frame serve a function for operation of the door itself. For
example, to keep non-display doors from freezing shut, anti-sweat
heaters are used to prevent condensation from accumulating around the
edge of the door.
Comments received regarding surface area determination suggest that
the approach provided in appendix A may result in inconsistent
interpretations as to how to determine this measurement. To clarify
this issue, DOE is proposing additional specification on how the
surface area is measured. DOE is proposing that the surface area bounds
of both display doors and non-display doors be the outer edge of the
frame. Specifically, DOE proposes to revise the term ``surface area''
to ``door surface area,'' and to define the new term as meaning the
product of the height and width of a walk-in door measured external to
the walk-in. Under this definition, the height and width dimensions
would be perpendicular to each other and parallel to the wall or panel
of the walk-in to which the door is affixed, the height and width
measurements would extend to the edge of the frame and frame flange (as
applicable) to which the door is affixed, and the surface area of a
display door and non-display door would be represented as Add and And,
respectively. In addition, DOE proposes to move the defined term from
the test procedure in appendix A because, as revised and in light of
the following proposal in section III.C.2.b, this term does not apply
to the proposed test procedure and is only relevant for determining
compliance with the standards. Instead, DOE proposes to include the
amended term and revised definition with the other definitions that are
broadly applicable to subpart R in 10 CFR 431.302.
b. Surface Area for Determining U-Factor
As stated previously, appendix A currently references NFRC 100,
which in turn references NFRC 102 for the determination of U-factor
through a physical test. When conducting a simulation, the U-factor is
calculated using the projected fenestration product area (Apt), or the
area of the rough opening in the wall or roof, for the fenestration
product, less installation clearances. See NFRC 100, section 3. When
conducting physical testing, the U-factor (Us) is calculated using
projected surface area (As) and is then converted to the final
standardized U-factor (UST). See ASTM C1199, sections 8.1.3 and 9.2.7
as referenced through NFRC 102. Projected surface area (As) is defined
as ``the projected area of test specimen (same as test specimen
aperture in surround panel).'' See ASTM C1199, section 3.3 as
referenced through NFRC 102.
Currently, equations 4-19 and 4-28 of appendix A specify that
surface area of display doors (Add) and non-display doors (And),
respectively, are used to convert a door's U-factor into a conduction
load. This conduction load represents the amount of heat that is
transferred from the exterior to the interior of the walk-in.
As discussed in section III.C.2.a, DOE is proposing to amend the
definitions of And and Add to be specific to the exterior plane of the
door, including the frame and frame flange as appropriate. Defining the
area in this manner is inconsistent with the area (As) used to
calculate U-factor in NFRC 102-2020.
As part of the June 2021 RFI, DOE sought comment on this
inconsistency and feedback on specifying additional detail for the
surface area used to determine thermal conduction through a walk-in
door to differentiate it from the surface area used to determine the
maximum energy consumption of a walk-in door. 86 FR 32332, 32337.
NFRC stated that the area used to convert U-factor into energy use
and the area used to determine U-factor must be consistent when
calculating conduction load from thermal transmittance. (NFRC, No. 10
at pp. 2-3) NFRC also observed that NFRC 100, NFRC 102, ASTM C1199 and
ASTM C1363 all define the area for U-factor based ``n ``projec''ed''
specimen ``r ``open''ng'' area in the wall through which the door is
installed. Id. NFRC further asserted that since the surface area as
defined by Add and And are different from the projected area, heat flow
is miscalculated when the tested U-factor is inserted into equations 4-
19 and 4-28. Id. AHRI and Hussmann declared that they determine surface
area in a manner consistent with the DOE regulations in 10 CFR parts
429 and 431 and that they do not see a distinction that warrants
determining surface area differently in these instances. (AHRI, No. 11
at p. 7; Hussmann, No. 18 at p. 9)
Imperial Brown stated that for a non-display door, the outer frame
is equivalent to a walk-in panel and therefore the frame would have a
limited impact on the U-factor calculation of the swinging or sliding
portion of the door. (Imperial Brown, No. 15 at p. 2) Imperial Brown
separately defined the two types of non-display doors they manufacture,
defining a ``panel frame'' as a frame that is connected in-line with
other walk-in panels and a ``flat frame'' as a frame that is typically
used in retrofit applications or by door-only manufacturers which are
non-insulating and mount over and are fastened to walk-in panels. (Id.
at p. 1) Imperial Brown suggested that manufacturers not be required to
separately test basic models for U-factor which differ in their frame
type because they believe ``panel'' frames and ``flat'' frames to be
equivalent in performance
[[Page 23940]]
once mounted. Imperial Brown recommended that the same U-factor
determined for a door with a ``panel frame'' be used for an otherwise
the same door with a ``flat frame.'' (Id. at p. 2)
Based on this feedback, DOE has preliminarily determined that using
the same area that is used to determine U-factor (As in NFRC 102 and
ASTM C1199 as referenced) to convert U-factor into a conduction load,
rather than the proposed revised term for door surface area in section
III.C.2.a (Add or And) results in a more representative conduction load
and provides for improved consistency in application of the test
procedure across all walk-in doors. As such, DOE proposes to specify
that the projected area of the test specimen, As, as defined in ASTM
C1199, or the area used to determine U-factor is the area used for
converting the tested U-factor, UST, into a conduction load in appendix
A. DOE recognizes that this may not change ratings for some doors,
where As is equivalent to And or Add, but it may result in slightly
lower ratings of energy consumption for other doors, where As is less
than And or Add. DOE expects that since this proposed detail would
either result in a reduced energy consumption or have no impact, there
would be no need for manufacturers to retest or re-rate. Additional
details on how this proposed detail impacts retesting and re-rating are
further discussed in section III.J.1.
In response to Imperial Brown's assertion that the frame has a
limited impact on the thermal performance of the door, DOE testing of
non-display doors found that inclusion of the frame in the U-factor
test (which resulted in a 34 to 52 percent increase in total door area)
increased the heat transferred through the door assembly by 23 to 139
percent compared to heat transfer through the door leaf alone. This
implies that including the frame in the U-factor test does have a
measurable impact on the thermal performance of the door assembly.
Therefore, DOE also proposes to specify in appendix A that the U-factor
test includes the frame of the door to improve consistency in
application of the test procedure across all walk-in doors.
3. Electrical Door Components
Sections 4.4.2 and 4.5.2 of appendix A include provisions for
calculating the direct energy consumption of electrical components of
display doors and non-display doors, respectively. For example,
electrical components associated with doors could include, but are not
limited to: Heater wire (for anti-sweat or anti-freeze application);
lights (including display door lighting systems); control system units;
and sensors. See appendix A, sections 4.4.2 and 4.5.2. For each
electricity-consuming component, the calculation of energy consumption
is based on the component's ``rated power'' rather than a measurement
of its power draw. Section 3.5 of appendix A defines ``rated power'' as
the electricity consuming device's power as specified (1) on the
device's nameplate or (2) from the device's product data sheet if the
device does not have a nameplate or such nameplate does not list the
device's power.
DOE has observed that walk-in doors often provide a single
nameplate for the door, rather than providing individual nameplates for
each electricity-consuming device. In many cases, the nameplate does
not provide separate power information for the different electrical
components. Also, the nameplate often specifies voltage and amperage (a
measure of current) ratings without providing wattage (a measure of
power) ratings, as is referenced by the definition of ``rated power.''
While the wattage is equal to voltage multiplied by the current for
many components, this may not be true for all components that may be
part of a walk-in door assembly. Furthermore, nameplate labels
typically do not specify whether any listed values of rated power or
amperage represent the maximum operation conditions or continuous
steady state operating conditions, which could differ for components
such as motors that experience an initial surge in power before power
use levels off. These issues make calculating a door's total energy
consumption a challenge for a test facility that does not have in-depth
knowledge of the electrical characteristics of the door components.
As part of the June 2021 RFI, DOE requested comment on whether, and
if so how, an option for direct component power measurement could be
included in the test procedure or DOE's CCE provisions to allow for a
more accurate accounting of the direct electrical energy consumption of
WICF doors. 86 FR 32332, 32338.
ASAP supported adding an option for direct measurement of power
consumed by door electrical components. (ASAP, No. 13 at p. 1) The CA
IOUs also supported direct measurement of power used by door
components, but more specifically for components designed to operate at
partial nameplate power such as door motors or powered door closers.
The CA IOUs stated that, in their experience, power measurement for
resistance components like lighting and door heaters are not necessary
if these components are designed to operate at full nameplate power.
They recommended that the electrical energy consumption of door motors
be reported per door opening and that the electrical energy consumption
be calculated as the actual power consumption of the motor multiplied
by the duration of the door opening and closing. (CA IOUs, No. 14 at p.
4) Hussmann and Imperial Brown supported maintaining the current
approach of using rated power for calculating direct electrical energy
consumption and did not see a need for the measurement option.
(Hussmann, No. 18 at p. 10; Imperial Brown, No. 15 at pp. 2-3) Imperial
Brown also stated that control components are typically rated at 5
Watts or less and that they should be excluded from the calculation of
direct electrical energy consumption. (Imperial Brown, No. 15 at pp. 2-
3)
DOE is not proposing to include provisions requiring measurement of
power consumption of electrical door components in the test procedure
in appendix A because additional investigation is needed. However, DOE
has observed that some manufacturers may be certifying door motor power
as the output power rating of the motor, rather than the input power of
the motor. Thus, DOE is proposing to specify in appendix A that the
rated power of each electrical component, Prated,u,t, would
be the rated input power of each component because the input power
represents power consumption.
Additionally, DOE has observed through testing that the measured
power of some walk-in door electrical components exceeds either the
certified or nameplate power values of these electrical components. For
the purposes of enforcement testing, DOE is proposing in 10 CFR
429.134(q) that DOE may validate the certified or nameplate power
values of an electrical component by measuring the power when the
device is energized using a power supply that provides power within the
allowable voltage range listed on the nameplate. If the measured input
power is more than 10 percent higher than the power listed on the
nameplate or the rated input power in a manufacturer's certification,
then the measured input power would be used in the energy consumption
calculation. For electrical components with controls, the maximum input
wattage observed while energizing the device and activating the control
would be considered the measured input power.
4. Percent Time Off Values
The test procedure also assigns percent time off (``PTO'') values
to various walk-in door components. PTO
[[Page 23941]]
values are applied to reflect the hours in a day that an electricity-
consuming device operates at its full-rated or certified power (i.e.,
daily component energy use is calculated assuming that the component
operates at its rated power for a number of hours equal to 24
multiplied by -1 - PTO)). PTO values are not incorporated in the rated
or certified power of an electricity-consuming device. Table III.3
lists the PTO values in the current DOE test procedure for walk-in
doors.
Table III.3--Assigned PTO Values for Walk-in Door Components
------------------------------------------------------------------------
Percent time
Component type off (PTO) (%)
------------------------------------------------------------------------
Lights without timers, control system or other demand- 25
based control..........................................
Lights with timers, control system or other demand-based 50
control................................................
Anti-sweat heaters without timers, control system or 0
other demand-based control.............................
Anti-sweat heaters on walk-in cooler doors with timers, 75
control system or other demand-based control...........
Anti-sweat heaters on walk-in freezer doors with timers, 50
control system or other demand-based control...........
All other electricity consuming devices without timers, 0
control systems, or other auto-shut-off systems........
All other electricity consuming devices for which it can 25
be demonstrated that the device is controlled by a
preinstalled timer, control system or other auto- shut-
off system.............................................
------------------------------------------------------------------------
As discussed in the June 2021 RFI, DOE has granted waivers to
several manufacturers of doors with motorized door openers, allowing
for the use of a different PTO for motors. 86 FR 32332, 32338-32339.
The manufacturers who requested and were granted waivers and the PTO
defined in their alternate test procedure are shown in Table III.4.
Table III.4--PTO Values Granted in Decision and Orders for Manufacturers
of Doors With Motorized Door Openers
------------------------------------------------------------------------
Decision and order
Manufacturer Percent time Federal Register
off (PTO) (%) citation
------------------------------------------------------------------------
HH Technologies................... 96 83 FR 53457. (Oct.
23, 2018).
Jamison Door Company.............. 93.5 83 FR 53460. (Oct.
23, 2018).
Senneca Holdings.................. 97 86 FR 75. (Jan. 4,
2021).
Hercules.......................... 92 86 FR 17801. (Apr.
6, 2021).
------------------------------------------------------------------------
In the June 2021 RFI, DOE requested comment on the current PTO
values for all electricity-consuming devices, whether these values
should be amended, and whether specific values should be added for
certain electrical components, such as motors. 86 FR 32332, 32339.
In response, Hussmann stated that they determine energy consumption
consistent with DOE's regulations in parts 429 and 431 and do not see a
need to change the current PTO values. (Hussmann, No. 18 at p. 10) ASAP
supported adding specific PTO values for motorized door openers because
they believe it will provide similar treatment for these components as
for other electrical components and eliminate the need for ongoing test
procedure waivers. (ASAP, No. at p. 1) The CA IOUs recommended that DOE
reduce the usage factor of door opening motors from 75 percent to 5
percent or less (i.e., implement a PTO of 95 percent or greater). In
their comments, the CA IOUs provided anecdotal data for two food
service sites where doors were open an average of 20 and 40 minutes per
day. The CA IOUs observed that if these doors had motors, the motor on
time would be even less than the time recorded in the open position.
Additionally, the CA IOUs recommended that DOE explore the differences
in opening patterns among passage, freight, and display doors and
potentially adjust the door motor PTO based on door opening pattern for
each corresponding class. (CA IOUs, No. 14 at pp. 5-6)
As shown in Table III.4, each manufacturer requested a PTO value
specific to their door and motor characteristics, resulting in four
different PTO values. For this proposal, DOE evaluated a PTO that could
be used to consistently evaluate energy consumption of doors with
motors and would be sufficiently representative. Recognizing that the
PTO values requested in the waivers are relatively close to one
another, DOE calculated an average PTO value based on the information
received in the waivers and is proposing to specify one PTO value for
all basic models of doors with motors to use. This approach results in
a more representative test procedure for doors with motors as compared
to the current value specified for other electricity-consuming devices
in appendix A. The intent of the PTO value is not to reflect
behaviorally-related energy consumption of each individual installation
of a door with a motor, but to provide a more representative means for
comparison of walk-in door performance.
DOE calculated an average PTO value, as follows. For each motorized
door offering from manufacturers that were granted waivers, DOE used
the cycle rating as specified in the product literature. When a cycle
rating was not provided in the product literature, DOE used its
previously estimated number of door openings per day of 60 for passage
doors and 120 for freight doors, respectively.\20\ 75 FR 55068, 55085.
[[Page 23942]]
DOE then calculated the PTO range for each motor offering using the
cycle rating or DOE's cycle assumption, the maximum opening size
offered by the manufacturer, and the minimum and maximum operating
speeds of the motor. DOE averaged these PTO ranges across each motor
offering and then averaged them across all manufacturers. This yielded
an average PTO of 97 percent.
---------------------------------------------------------------------------
\20\ DOE's previously estimated door openings per day were
relevant for a proposal to address door opening infiltration in the
test procedure introduced in a supplemental notice of proposed
rulemaking from September 9, 2010. Ultimately, DOE did not adopt
test procedure provisions addressing door opening infiltration,
having determined that a typical door manufacturer has very few
direct means for reducing the door infiltration on its own. 76 FR
21580, 21595 (Apr. 15, 2011).
---------------------------------------------------------------------------
Considering the waivers granted, DOE's own calculations, and
comments received, DOE is proposing to adopt a door motor PTO value of
97 percent for display doors with motors and non-display doors with
motors.
As discussed in the June 2021 RFI, DOE is aware that some
manufacturers design and market walk-in cooler display doors for high
humidity applications. Ratings from the CCMS database show these doors
have more anti-sweat heater power per door opening area than standard
cooler display doors. 86 FR 32332, 32339. Section 4.4.2(a)(2) of
appendix A requires a PTO value of 50 percent be used when determining
the direct energy consumption for anti-sweat heaters with timers,
control systems, or other demand-based controls situated within a walk-
in cooler door (which would include walk-in cooler doors marketed for
high humidity applications). This approach assumes that the anti-sweat
heaters are not operating for 50 percent of the time. DOE recognizes
that anti-sweat heaters may be in operation for a different amount of
time in high humidity installations than in standard installations. In
the June 2021 RFI, DOE requested comment on whether the current PTO of
50 percent is appropriate for evaluating direct energy consumption of
anti-sweat heaters with controls for walk-in cooler doors marketed for
high humidity applications and the amount of time per day or per year
that anti-sweat heaters with controls are off for high humidity doors.
Id.
In response, DOE received comments from Anthony, AHRI, and Hussmann
regarding the maximum energy consumption of high humidity doors.
(Anthony, No. 8 at p. 3; AHRI, No. 11 at pp. 7-8; Hussmann, No. 18 at
p. 10) However, as the responses of these comments were more focused on
the standards, DOE plans to address these comments as part of a
separate standards rulemaking for this equipment. DOE did not receive
any comments regarding whether the PTO in the test procedure for anti-
sweat heaters with controls sited on high humidity doors should be
modified nor any data on the amount of time the anti-sweat heaters
operate on high-humidity doors as compared to standard doors (i.e.,
cooler display doors). DOE is not proposing any changes to the PTO
values for anti-sweat heaters sited on high humidity doors at this
time.
5. EER Values
To calculate the daily energy consumption associated with heat loss
through a walk-in door, appendix A requires dividing the calculated
heat loss rate by specified energy efficiency ratio (``EER'') values of
12.4 Btu per Watt-hour (``Btu/W-h'') for coolers and 6.3 Btu/(W-h) for
freezers. Appendix A, sections 4.4.4(a) and 4.5.4(a). DOE selected EER
values of 12.4 Btu/(W-h) for coolers and 6.3 Btu/(W-h) for freezers
because these are typical EER values of walk-in cooler and walk-in
freezer refrigeration systems, respectively.\21\ 75 FR 186, 209 (Jan.
4, 2010); 76 FR 21580, 21593-21594 (Apr. 15, 2011). The DOE test
procedure in subpart R, appendix C, also assigns nominal EER values,
which correspond to the appropriate adjusted dew point temperature in
Table 17 of AHRI 1250-2009,\22\ when testing the refrigeration systems
of walk-in unit coolers alone. The resulting EER values for unit
coolers tested alone are 13.3 Btu/(W-h) for coolers and 6.6 Btu/(W-h)
for freezers, which are different than the EER values of 12.4 Btu/(W-h)
and 6.3 Btu/(W-h), respectively, applied to walk-in doors, as described
previously. In the June 2021 RFI, DOE sought feedback on the EER values
specified in appendix A used to calculate daily energy consumption for
walk-in doors and the values used to test unit coolers as specified in
subpart R, appendix C. Specifically, DOE requested comment on whether
the EER values used for door testing and unit cooler testing consistent
with each other, and if so, which values are more representative. 86 FR
32332, 32339.
---------------------------------------------------------------------------
\21\ The difference in EER values between coolers and freezers
reflects the relative efficiency of the refrigeration equipment for
the associated application. 75 FR 186, 197. As the temperature of
the air surrounding the evaporator coil drops (that is, when
considering a freezer relative to a cooler), thermodynamics dictates
that the system effectiveness at removing heat per unit of
electrical input energy decreases. Id.
\22\ The dewpoint temperature to be used for testing unit
coolers alone is defined in section 3.3.1 of appendix C to be the
Suction A saturation condition provided in Tables 15 or 16 of
appendix C (for refrigerator unit coolers and freezer unit coolers,
respectively). Table 15 for refrigerator unit coolers defines the
Suction A saturation condition (i.e., dewpoint temperature) as 25
[deg]F. Table 16 for freezer unit coolers defines the Suction A
dewpoint temperature as -20 [deg]F. Furthermore, section 7.9.1 of
AHRI 1250-2009 specifies that for unit coolers rated at a suction
dewpoint other than 19 [deg]F for a coolers and -26 [deg]F for a
freezer, the Adjusted Dewpoint Value shall be 2 [deg]F less than the
unit cooler rating suction dewpoint--resulting in adjusted dewpoint
values of 23 [deg]F and -22 [deg]F for refrigerator unit coolers and
freezer unit coolers, respectively.
---------------------------------------------------------------------------
Anthony responded that the EER values referenced in subpart R,
appendix C (i.e., 13.3 Btu/(W-h) for coolers and 6.6 Btu/(W-h) for
freezers), better reflect current compressor efficiency for walk-in
refrigeration systems. (Anthony, No. 8 at p. 3) National Refrigeration
encouraged DOE to keep the current EER values, stating that they
believe the values are accurate, but did not specify if they were
referring to walk-in door or refrigeration system EER values. (National
Refrigeration, No. 17 at p. 1) Keeprite, Lennox, and AHRI all supported
maintaining the EER values applicable to unit coolers in subpart R,
appendix C. (Keeprite, No. 12 at p. 2; Lennox, No. 9 at p. 4; AHRI, No.
11 at p. 8)
Based on the comments received, it is not clear that there is an
advantage to harmonizing the EER values between appendix A and subpart
R, appendix C. Therefore, DOE is not proposing to change the subpart R,
appendix C, EER values pertaining to walk-in refrigeration systems.
Additionally, with respect to envelope components, DOE is not
proposing to align the EER values in appendix A for calculating the
energy consumption of envelope components with the EER values used for
testing unit coolers alone in subpart R, appendix C, at this time. DOE
originally defined nominal EER values in appendix A because an envelope
component manufacturer generally cannot control what refrigeration
equipment is installed, and the defined EER value is intended to
provide a nominal means of comparison rather than reflecting an actual
walk-in installation. 76 FR 21580, 21593 (Apr. 15, 2011). In other
words, the EER values used to estimate energy consumption of the
envelope components is a constant. DOE notes that the difference
between the EER values used in appendix A for doors and those used in
subpart R, appendix C, for unit coolers is seven percent for coolers
and five percent for freezers, which would have minimal impact on rated
values but would require manufacturers to retest and re-rate energy
consumption without necessarily providing a more representative test
procedure.
[[Page 23943]]
6. Air Infiltration Reduction
EPCA includes prescriptive requirements for doors used in walk-in
applications which are intended to reduce air infiltration.
Specifically, walk-ins must have (A) automatic door closers that firmly
close all walk-in doors that have been closed to within 1 inch of full
closure (excluding doors wider than 3 feet 9 inches or taller than 7
feet), and (B) strip doors, spring-hinged doors, or other method of
minimizing infiltration when doors are open. (42 U.S.C. 6313(f)(1)(A)-
(B)) DOE previously proposed methods for determining the thermal energy
leakage due to steady state infiltration through the seals of a closed
door and door opening infiltration. DOE did not ultimately adopt these
methods as part of the test procedure because DOE concluded that steady
state infiltration was primarily influenced by on-site assembly
practices rather than the performance of individual components. 76 FR
21580, 21594-21595 (April 15, 2011) (``April 2011 final rule'').
Similarly, DOE stated that, based on its experience with the door
manufacturing industry, door opening infiltration is primarily reduced
by incorporating a separate infiltration reduction device at the
assembly stage of the complete walk-in. Id. In the June 2021 RFI, DOE
invited comment on whether it should account for steady state and/or
door opening infiltration in its test procedure. 86 FR 32332, 32340-
32341. DOE also requested test methods and calculations to quantify
heat load, the associated costs of any suggested methods, and
supporting data on door usage patterns. Id.
ASAP encouraged DOE to incorporate a measurement of air
infiltration into the test procedure for walk-in doors because it would
improve representativeness and encourage the development and deployment
of technologies that could reduce infiltration and save energy. (ASAP,
No. 13 at p. 2) The CA IOUs recommended that DOE consider specifically
incorporating door opening infiltration energy into the test procedure.
They also suggested that DOE validate the actual savings of devices
such as air curtains to determine if the test method should be refined
to more accurately represent these features in the determination of
walk-in performance. (CA IOUs, No. 14 at p. 6) In contrast, Imperial
Brown stated that including air infiltration in the test procedure
would be burdensome and cost prohibitive because most WICF doors are
custom-made. (Imperial Brown, No. 15 at p. 3)
DOE is not proposing to include air infiltration in the test
procedure for determining energy consumption of walk-in envelope
components at this time because additional investigation is needed. DOE
intends to consider data on the magnitude of air infiltration for walk-
ins as it becomes available for appropriate evaluation of the
representativeness of including it in the test procedure for walk-in
doors. However, as previously mentioned, EPCA requires air infiltration
limiting devices on all doors. (42 U.S.C. 6313(f)(1)(A)-(B)) Even
though air infiltration is not currently evaluated as part of the
current test procedure and is thus not part of the performance
standard, all walk-in doors are subject to the prescriptive
requirements pertaining to air infiltration limiting devices.
D. Proposed Amendments to the Test Procedure in Appendix A for Display
Panels
Appendix A specifies the test procedure to determine energy
consumption of walk-in display panels, which are not currently subject
to any performance standards in terms of daily energy consumption, but
are subject to the prescriptive requirements at 10 CFR 431.306.
In the June 2021 RFI, DOE requested specific comment on the current
test procedure for determining energy consumption for display panels
and whether any amendments to this procedure were warranted. 86 FR
32332, 32342. In response, Anthony and NFRC commented that the test
procedure for display panels should be identical to the test procedure
for display doors. (Anthony, No. 8 at p. 4; NFRC, No. 10 at p. 4)
DOE is proposing that the changes proposed throughout section III.C
for determining conduction load and energy consumption of display doors
would also be applicable to determining display panel conduction load
and energy consumption, except for the provisions applicable to
electrical components and percent time off values.
E. Proposed Amendments to the Test Procedure in Appendix B for Panels
and Non-Display Doors
The insulation R-value of walk-in non-display panels and non-
display doors is determined using appendix B. In this NOPR, DOE is
proposing to modify appendix B to improve test representativeness and
repeatability. Specifically, DOE is proposing to make the following
revisions to appendix B: (1) Reference the updated industry standard
ASTM C518-17; (2) include more detailed provisions on measuring
insulation thickness and test sample thickness; (3) provide additional
guidance on determining parallelism and flatness of test specimen; and
(4) reorganize appendix B so it is easier for stakeholders to follow as
a step-by-step test procedure.
DOE does not expect that the changes it is proposing in this
section would have a significant impact on measured R-value of
insulation. Rather, the revisions proposed for appendix B address
repeatability issues that DOE has observed through its testing of the
insulation of walk-in panels.
The following sections describe the modifications that DOE is
proposing to appendix B, the test procedure for determining the R-value
of walk-in envelope component insulation. DOE discusses the proposed
changes specifically in the context of walk-in panels; however, DOE
notes that non-display doors are also subject to the prescriptive R-
value requirement at 10 CFR 431.306(a)(3) and that the R-value for
walk-in door insulation is determined using appendix B.
1. Specimen Conditioning
In the June 2021 RFI, DOE noted that the test specimen conditioning
instruction and example given in section 7.3 of ASTM C518 conflict with
the provision in section 4.5 of the DOE test procedure at appendix B
that requires testing per ASTM C518 be completed within 24 hours of
specimens being cut for the purpose of testing. 86 FR 32332, 32341-
32342. Section 7.3 of ASTM C518 directs that a test specimen be
conditioned prior to testing and states that this be done per material
specifications. If material specifications for conditioning are not
provided, the specimen preparation shall be conducted so as not to
expose the specimen to conditions which would change the specimen in an
irreversible manner. Section 7.3 of ASTM C518 provides an example of a
material specification that requires test specimen conditioning at 72
[deg]F and 50 percent relative humidity until less than a one percent
change in mass is observed over a 24-hour period. As part of the June
2021 RFI, DOE sought comment on whether manufacturers of insulation
specify conditioning for insulation materials that differ from the
typical approach described in ASTM C518. DOE also requested feedback on
whether more than one 24-hour conditioning period is ever needed to
complete specimen conditioning given ASTM's requirement regarding
change in mass. Lastly, DOE requested data on panel performance for
conditioning times less than 24 hours, specifically,
[[Page 23944]]
how conditioning time impacts the accuracy, repeatability, and
representativeness of the test. 86 FR 32332, 32342.
Imperial Brown stated that the panel should cure for 30 days before
a test specimen is cut and that the test specimen should be tested
within 24 hours of being cut. Imperial Brown asserted that conditioning
for longer than 24 hours would create an issue with outgassing,
particularly on a small test specimen. Additionally, Imperial Brown
observed that the 180-day conditioning period specified in ASTM C1029-
2015, ``Standard Specification for Spray-Applied Rigid Cellular
Polyurethane Thermal Insulation'' would be unrealistic and a
significant test burden. (Imperial Brown, No. 15 at p. 3)
In response to the suggestion by Imperial Brown that a panel should
cure for 30 days before a test, DOE notes that section 4.5 of the
current test procedure in appendix B already specifies that foam
insulation be tested after it is produced in its final chemical form.
For foam-in-place insulation, this means the foam has cured as intended
and is ready for use in a finished panel. In response to the comments
received regarding outgassing of the test specimen for conditioning
times beyond 24 hours, preliminary tests conducted by DOE demonstrate
negligible change in mass of the test specimen within 24 to 48 hours
and negligible difference in R-value when compared to a test specimen
from the same foam that was tested within 24 hours. Regarding the 180-
day conditioning period specified in ASTM C1029-2015, DOE has
tentatively concluded that this timeframe for testing is unrealistic
and burdensome. Considering all the information at hand, DOE is not
proposing any changes to the current requirement that testing be
completed with 24 hours of the test specimen being cut from the
envelope component. Correspondingly, DOE is not proposing to reference
Section 7.3 of ASTM C518-17 regarding specimen conditioning.
2. Total Insulation and Test Specimen Thickness
Section 4.5 of appendix B currently requires that K-factor of a 1
0.1-inch sample of insulation be determined according to
ASTM C518-04. The walk-in envelope component insulation R-value is
determined by dividing the envelope component insulation thickness by
the K-factor. As mentioned in the June 2021 RFI, the measurement of
total insulation thickness is important in determining the envelope
component's insulation R-value. 86 FR 32332, 32341. As part of the June
2021 RFI, DOE requested comment on how panel thickness is typically
measured. Id. DOE did not receive any comments in response to this
request.
In order to make the test procedure in appendix B more repeatable,
DOE is proposing to include instructions for determining both the total
insulation thickness as well as the test specimen insulation thickness
prior to conducting the test to determine K-factor using ASTM C518-17.
DOE is also proposing step-by-step instructions for specimen
preparation, including detailed instructions of the number and
locations of thickness and area measurements and from where the test
specimen should be removed from the overall envelope component. DOE
proposes to require the following steps for determining the total
thickness of the foam, tfoam, from which the final R-value
would be calculated:
The thickness around the perimeter of the envelope
component is determined as the average of at least 8 measurements taken
around the perimeter, but avoiding the edge region; \23\
---------------------------------------------------------------------------
\23\ Edge region means a region of the panel that is wide enough
to encompass any framing members. If the panel contains framing
members (e.g., a wood frame) then the width of the edge region must
be as wide as any framing member plus an additional 2 in. 0.25 in. See section 3.1 of appendix B.
---------------------------------------------------------------------------
The area of the entire envelope component is calculated as
the width by the height of the envelope component;
A sample is cut from the center of the envelope component
relative to the envelope component's width and height. The specimen to
be tested using ASTM C518-17 would be cut from the center sample;
The thickness of the sample cut and removed from the
center of the envelope component is determined as the average of at
least 8 measurements, with 2 measurements taken in each quadrant;
The area of the sample cut and removed from the center of
the envelope component is determined as the width by the height of the
cut sample;
Any facers on the sample cut from the envelope component
shall be removed while minimally disturbing the foam and the thickness
of each facer shall be the average of at least 4 measurements;
The average total thickness of the foam shall then be
determined by calculating an area-weighted average thickness of the
complete envelope component less the thickness of the facers.
For preparing and determining the thickness of the 1-inch test
specimen, DOE proposes to include the following steps:
A 1 0.1-inch-thick specimen shall be cut from
the center of the cut envelope sample removed from the center of the
envelope component;
Prior to testing, the average of at least nine thickness
measurements at evenly-spaced intervals around the test specimen shall
be the thickness of the test specimen, L.
Issue 9: DOE requests feedback on the proposed provisions relating
to test specimen and total insulation thickness and test specimen
preparation prior to conducting the ASTM C518-17 test.
3. Parallelism and Flatness
The test procedure for determining R-value also requires that the
two surfaces of the tested sample that contact the hot plate assemblies
(as defined in ASTM C518) maintain 0.03 inches flatness
tolerance and maintain parallelism with respect to one another within a
tolerance of 0.03 inches.\24\ See appendix B, section 4.5.
As mentioned in the June 2021 RFI, the current test procedure does not
provide direction on how flatness and parallelism should be measured or
calculated. 86 FR 32332, 32341. As part of the June 2021 RFI, DOE
sought comment on how flatness and parallelism are determined by test
laboratories and whether the DOE test procedure should include
instruction on how to determine these parameters. Id. While DOE
received no comments in response to this request for comment, DOE
believes that accurate and repeatable determination of a specimen's R-
value requires the specimen under test to be both flat and parallel.
Therefore, DOE proposes to include the following steps for determining
the parallelism and flatness of the tested specimen in appendix B:
---------------------------------------------------------------------------
\24\ Maintaining a flatness tolerance means that no part of a
given surface is more distant than the tolerance from the ``best-fit
perfectly flat plane'' representing the surface. Maintaining
parallelism tolerance means that the range of distances between the
best-fit perfectly flat planes representing the two surfaces is no
more than twice the tolerance (e.g., for square surfaces, the
distance between the most distant corners of the perfectly flat
planes minus the distance between the closest corners is no more
than twice the tolerance).
---------------------------------------------------------------------------
Prior to determining the specimen thickness, the specimen
would be placed on a flat surface and gravity will determine the
specimen's position on the surface. As specified previously, a minimum
of nine thickness measurements would be taken at equidistant positions
on the specimen. These measurements would be associated with side 1 of
the specimen.
The least squares plane of side 1 is determined based on
the height measurements taken. The theoretical height of the least
squares plane is
[[Page 23945]]
determined at each measurement location in the x and y (length and
width) direction of the specimen.
The difference at each measurement location between actual
height measurement and theoretical height measurement based on the
least squares plane is calculated. The maximum value minus the minimum
value is the flatness associated with this side (side 1). In order for
each side of the specimen to be considered flat, this value would need
to be less than or equal to 0.03 inches.
Flip the specimen so that side 1 is now on the flat
surface and let gravity determine the specimen position on the surface.
Repeat the above steps for side 2 of the specimen.
To determine if each side of the specimen is parallel, the
theoretical height at the four corners (i.e., at points (0,0), (0,12),
(12,0), and (12,12)) of the specimen must be calculated using the least
squares plane. The difference in the maximum and minimum heights would
represent the parallelism of one side and would need to be less than or
equal to 0.03 inches for the specimen to be considered parallel.
Issue 10: DOE requests feedback on the proposed provisions relating
to determining parallelism and flatness of the test specimen.
4. Insulation Aging
In the April 2011 final rule, DOE adopted a test procedure that
referenced two industry test standards \25\ that considered aging of
insulation for foams that experience aging. 76 FR 21580, 21588-21592.
However, after receiving comments concerning test burden and the
availability of labs to conduct the test procedure, DOE re-evaluated
its earlier decision and removed this portion of the walk-in panel test
procedure in the final rule published May 13, 2014 (``May 2014 final
rule''). 79 FR 27388, 27405-27406. Although the current test procedure
for determining panel R-value does not account for aging, manufacturers
have raised concern regarding insulation aging and its potential effect
on testing results.
---------------------------------------------------------------------------
\25\ DOE referenced DIN EN 13164:2009-02, ``Thermal insulation
products for buildings--Factory made products of extruded
polystyrene foam (XPS)--Specification'' and DIN EN 13165:2009-02,
``Thermal insulation products for buildings--Factory made rigid
polyurethane foam (PUR) products--Specification.''
---------------------------------------------------------------------------
``Aging'' of foam insulation refers to how diffusion of blowing
agents out of the foam and diffusion of air into the foam impacts
thermal resistance of insulation materials. The gaseous blowing agents
contained in the foam provide the foam with much of its insulating
performance, represented by the R-value of the foam material. Because
air has a lower insulating value than the blowing agents used in foam
insulation, the increased ratio of air to blowing agent reduces the
foam insulation performance, which reduces the R-value of the foam
material. The building industry uses long-term thermal resistance
(``LTTR'') to represent the R-value of foam material over its lifetime
by describing the insulating performance changes due to diffusion over
time. The presence of impermeable facers on a foam structure may delay
the rate of aging or reduce the decrease in R-value when compared to a
foam structure that is unfaced or has permeable facers. Blowing agents
and temperature and humidity conditions may also affect the amount or
rate of aging that occurs in a foam structure.
Since the May 2014 final rule, DOE worked with the Oak Ridge
National Laboratory (``ORNL'') to conduct a study on performance aging
and thermal bridging of walk-in cooler and freezer panels.\26\ In this
study, multiple panels from five manufacturers were allowed to age
intact (i.e., with facers attached) at room temperature, with 1-inch
samples taken from the middle of a given panel for testing according to
the test procedure in appendix B. These samples were tested upon
receipt of the panels and extracted at various times throughout 5 years
from intact panels (i.e., with facers attached). Aging panels with
their facers attached is representative of how panels are stored and,
ultimately, installed for use in a walk-in box. Appendix B does not
test with facers because, as previously stated, the DOE test procedure
evaluates only the R-value of the foam insulation--not the R-value of
the entire panel.
---------------------------------------------------------------------------
\26\ A presentation on ORNL's study can be found online at
https://www.osti.gov/biblio/1844325-impact-thermal-bridging-imperfections-aging-effective-value-walk-cooler-freezer-panels. DOE
acknowledges that panels are shipped for assembly in walk-ins with
the foam already in final chemical form between facers. Thus, the
most applicable evaluation of change in insulation R-value over time
is demonstrated by the red data points (labeled ``2'') for the foam
that remained intact with the facers on slides 26 through 30 of
ORNL's presentation.
---------------------------------------------------------------------------
Based on DOE evaluation of product literature, there are two common
ways to manufacture walk-in panels: (1) Foaming metal skins in place
using closed cell polyurethane foam (``PUF'') or (2) gluing layers of
previously-hardened foam to metal skins. DOE research suggests that PUF
is the most common insulation used in walk-ins. To manufacture PUF
panels, the PUF is injected and hardened using jigs that firmly
maintain exterior panel dimensions until the foam has cooled and
hardened. This process encourages standardization of panel dimensions
as jigs are expensive and typically have limited adjustability.
Extruded polystyrene (``XPS'') is used by some manufacturers to
construct walk-in panels. XPS-based walk-ins are built in layers of
XPS, a previously-hardened foam material that is shipped in sheets to
the original equipment manufacturer (``OEM''), where it is cut to the
desired shape and assembled. Customization is more common with XPS
panels. XPS strongly resists water absorption, preventing panels from
losing their insulative properties should water or condensation leaks
develop. Other layered panel assembly materials include
polyisocyanurate and expanded polystyrene (``EPS'') which are used less
but are still offered by some manufacturers. Polyisocyanurate has
similar advantages to XPS, but generally has lower thermal resistivity
at lower temperature conditions. EPS also has similar advantages to XPS
in terms of moisture absorption, but generally has a lower R-value. The
study conducted at ORNL evaluated four panel brands manufactured with
PUF and one panel brand manufactured using XPS. The R-value of
insulation measured by ORNL at the initial test date and most recent
test date are summarized in Table III.5.
Table III.5--Summary of R-value Test Results at Initial Test Date and Most Recent Test Date From ORNL Study
----------------------------------------------------------------------------------------------------------------
Number of years after
Label Foam type Temperature condition initial test R-value
----------------------------------------------------------------------------------------------------------------
F1..................... PUF.................... Freezer............... 0 (initial test)...... 31.2
2.3................... 30.9
F2..................... PUF.................... Freezer............... 0 (initial test)...... 31.8
4.2................... 30.3
[[Page 23946]]
C1..................... PUF.................... Cooler................ 0 (initial test)...... 28.2
4.8................... 26.8
C2..................... XPS.................... Cooler................ 0 (initial test)...... 25.0
4.7................... 23.1
C3..................... PUF.................... Cooler................ 0 (initial test)...... 28.0
0.5................... 27.8
----------------------------------------------------------------------------------------------------------------
Based on ORNL's study, DOE considers the effects of foam insulation
aging for walk-in refrigeration panels sold with facers to be minimal
when panel facers remain attached to the foam (i.e., when the panel
remains intact.). DOE understands that for the purposes of
certification and represented R-values, manufacturers are determining
their represented R-value by testing specimens from panels at the point
of manufacture (i.e., R-value without aging). For assessment and
enforcement testing conducted to support the enforcement of DOE's
energy conservation standards, DOE is generally able to test samples
within one to three months after receipt. The time lag from when the
panel is manufactured and when testing is conducted at a lab is
typically significantly shorter than that evaluated in the ORNL study;
therefore, DOE expects any reduction in R-value to be even less during
the period from date of manufacture to assessment or enforcement test
date. Additionally, walk-in panels received by DOE for assessment and
enforcement testing are evaluated upon arrival to ensure that they are
received intact (i.e., with facers) and undamaged and testing of the
specimen is completed within 24 hours of sample removal from the panel,
as specified in section 4.5 of the DOE test procedure in appendix B.
DOE does not expect any reduction in R-value within 24 hours of the
sample being cut from the panel.
Issue 11: DOE seeks comment on other comparable data or studies of
aging of foam panels that are representative of the foam insulation,
blowing agents, and panel construction currently used in the
manufacture of walk-in panels. DOE also requests comment on whether
manufacturers have been certifying R-value at time of manufacture or
after a period of aging.
5. Determining Energy Consumption of Panels That Are Not Display Panels
When DOE initially established the test procedures for components
of a WICF in its April 2011 final rule, DOE adopted a test method for
measuring the overall thermal transmittance of a walk-in panel,
including the impacts of thermal bridges \27\ and edge effects (e.g.,
due to framing materials and fixtures used to mount cam locks). 76 FR
21580, 21605-21612. This method was based on an existing industry test
method, incorporating by reference ASTM C1363. Id. However, after
receiving comments concerning test and cost burden and the lack of
availability of labs to conduct the test procedure, DOE re-evaluated
its earlier decision and removed this portion of the walk-in panel test
procedure in the May 2014 final rule. 79 FR 27388, 27405-27406. As
previously stated, the current test procedure in appendix B for non-
display panels evaluates insulation R-value according to ASTM C518-04.
In the June 2021 RFI, DOE requested information regarding panel
construction factors that would affect overall thermal transmission and
the magnitude of these effects. 86 FR 32332, 32342. DOE also requested
comment on alternative test methods to measure overall thermal
transmittance of a panel assembly along with the number of labs that
are qualified to run ASTM C1363. Id.
---------------------------------------------------------------------------
\27\ Thermal bridging occurs when a more conductive material
allows an easy pathway for heat flow across a thermal barrier.
---------------------------------------------------------------------------
ASAP and the CA IOUs encouraged DOE to consider a test method that
captures overall thermal transmittance of walk-in panels. (ASAP, No. 13
at p. 2; CA IOUs, No. 14 at p. 5) The CA IOUs specifically recommended
that the ASTM C1363 test be conducted on a wall panel assembly that
includes the panel joint to ensure the joint locking mechanism does not
significantly affect the thermal conductance of the assembly. The CA
IOUs also suggested that the tested joint assembly use a manufacturer-
recommended sealant representative of field installation. (CA IOUs, No.
14 at p. 5)
Imperial Brown urged DOE to maintain the current test procedure for
non-display panels based on insulation R-values determined using ASTM
C518. Imperial Brown stated that ASTM C1363 is unduly burdensome given
the custom nature of the walk-ins they manufacture and that this would
substantially increase their testing requirements. Imperial Brown also
remarked that the effect of panel edges or accessories is of little
value to the overall energy consumption of a walk-in and that
considering these effects would be equivalent to considering one
opening of the walk-in door per day. Specifically, Imperial Brown
stated that the panel edges and accessories are not considered when
calculating box loads and sizing refrigeration equipment because they
do not consider them to be an important factor in heat loss. Imperial
Brown also stressed that retesting will be required every few years as
they switch to different insulation chemicals to comply with other
regulations coming into effect (e.g., the Environmental Protection
Agency (``EPA'') phasedown of HFCs. (Imperial Brown, No. 15 at p. 3)
NFRC stated that all labs qualified to run NFRC 102 are qualified
to run ASTM C1363 and that there are currently ten labs accredited by
NFRC to run NFRC 102, and thus ASTM C1363. (NFRC, No. 10 at p. 4)
While commenters indicated that there are more laboratory
facilities now able to conduct an overall U-factor test procedure, the
concerns previously expressed regarding cost and test burden, which led
to the removal of this test procedure in the May 2014 AEDM final rule
(79 FR 27388, 27405-27406), remain. At this time, DOE is not proposing
to include a test procedure for determining energy consumption of non-
display panels and is proposing to maintain the R-value of insulation
test procedure in appendix B with the proposed amendments as described
previously in sections III.E.1 through III.E.4.
F. Proposed Amendments to Subpart R, Appendix C, to Determine
Compliance With the Current Energy Conservation Standards
Subpart R, appendix C, provides the test procedures to determine
the AWEF and net capacity of walk-in refrigeration
[[Page 23947]]
systems. DOE is proposing to modify subpart R, appendix C, to improve
test representativeness and repeatability. Specifically, DOE is
proposing to make the following revisions to subpart R, appendix C: (1)
Specify refrigeration test room conditions; (2) provide for a
temperature probe exception for small diameter refrigerant lines; (3)
incorporate a test setup hierarchy for laboratories to follow when
setting up a unit for test; (4) allow active cooling of the liquid line
in order to achieve the required 3 [deg]F subcooling at a refrigerant
mass flow meter; and (5) modify instrument accuracy and test
tolerances.
DOE does not expect that the changes it is proposing in this
section would alter measured capacity values or AWEF--which means that
no retesting or recertification would be required. Rather, the
revisions proposed for subpart R, appendix C, address repeatability
issues that DOE has observed through its testing of walk-in
refrigeration systems.
The following sections describe the modifications that DOE is
proposing to subpart R, appendix C.
1. Refrigeration Test Room Conditioning
The DOE test procedure for walk-in refrigeration systems has
requirements for test chambers to be at specific temperature and/or
humidity conditions. (See, e.g., Tables 3 through 16 of AHRI 1250-2009,
which is incorporated by reference in the DOE test procedure) Section
C6.2 of AHRI 1250-2009 appendix C requires that the environmental
chambers ``be equipped with essential air handling units and
controllers to process and maintain the enclosed air to any required
test conditions.'' This same requirement is in Section C5.2.2 of AHRI
1250-2020. However, DOE is aware that some test facilities rely on the
test unit to cool and dehumidify the test room, in some cases without
support from additional chamber conditioning systems. When unit coolers
with hot gas defrost are tested and certified alone, these unit coolers
may be paired with a condensing unit at a test facility that lacks hot
gas capability and would be unable to remove the frost accumulated
during pretest conditioning. Such frost would affect the results of the
capacity test.
DOE proposes to specify that for applicable system configurations
(matched pairs, single-packaged systems, and unit coolers tested
alone), the unit under test may be used to aid in achieving the
required test chamber conditions prior to beginning any steady state
test. However, the unit under test must be inspected and confirmed to
be free from frost before initiating steady state testing. This
additional instruction reflects DOE's understanding of the existing
practice followed by manufacturers and third-party laboratories who use
the unit under test to establish the required chamber conditions. The
proposed inspection requirement would ensure that a steady state test
is not started with frost on the coil. Starting a test with a frosted
coil would likely lead to reduced-efficiency and non-representative
test results, and DOE expects that test laboratories would have no
incentive to conduct tests with a frosted coil.
Issue 12: DOE requests comment on the proposed pretest coil
inspection requirement. DOE requests comment on whether the proposed
approach is inconsistent in any way with the way units under test are
used to assist in chamber conditioning by testing facilities, and if
so, in what way are the proposals inconsistent, and how could they be
changed to align with this practice.
2. Temperature Measurement Requirements
The current DOE test procedure requires all refrigerant temperature
measurements entering or leaving the unit cooler be measured by a
``temperature measuring instrument placed in a thermometer well and
inserted into the refrigerant stream. These wells shall be filled with
non-solidifying, thermal conducting liquid or paste to ensure the
temperature sensing instrument is exposed to a representative
temperature.'' AHRI 1250-2009 appendix C, Section C3.1.6. These
temperature measurements are used to determine refrigerant enthalpy as
part of the capacity measurement for matched pairs and unit coolers
tested alone (see AHRI 1250-2009, Section C8.5.1, Equations C1 and C2).
However, the capacity determination for dedicated condensing units
tested alone is based on the refrigerant conditions leaving the
condensing unit and standardized conditions leaving the unit cooler, as
specified in section 3.4.2.1 of subpart R, appendix C. DOE believes
that the added accuracy provided by immersing the temperature sensor in
the refrigerant or by the thermometer wells should be applied for the
temperature measurement used in the capacity calculation. Hence, DOE
proposes that the test procedure provide clarification that when
testing dedicated condensing units, the use of thermometer wells or
immersed sensors be used only at the condensing unit liquid outlet. DOE
believes this may reduce testing burden in cases where labs have been
using two sets of refrigerant-immersed temperature measurements when
testing dedicated condensing units alone.
Issue 13: DOE requests comment on its proposal to require use of
thermometer wells or sheathed sensors immersed in the refrigerant when
measuring temperature at the liquid outlet of the condensing unit and
to forego the requirement for this measurement technique for the
suction line when testing a dedicated condensing unit alone.
DOE has found that implementing the current thermometer well
requirement for refrigerant lines with outer diameter \1/2\-inch or
less can restrict the refrigerant flow and thus affect the
measurements. To rectify this issue and to ensure that all walk-in
refrigeration systems can be tested according to the DOE test
procedure, DOE proposes allowing an alternative approach when the
refrigerant line tubing diameter is \1/2\-inch or less in which the
temperature measurement would be made using two surface-mounted
measuring instruments with a minimum accuracy of 0.5
[deg]F, which would be averaged to obtain the reading. DOE notes that
when using the Dual Instrumentation method described in Section C8 of
AHRI 1250-2009 appendix C, the two surface measurements described would
constitute one temperature measurement, rather than the two
measurements required for the test method. Additionally, DOE proposes
that the two measuring instruments must be mounted on the pipe
separated by 180-degrees around the refrigerant tube circumference. To
ensure measurements are not affected by changes in ambient temperature,
DOE proposes requiring use of 1-inch-thick insulation around the
measuring instruments that extends 6-inches up- and down-stream of the
measurement locations. Where this technique is used to measure
temperature at the expansion valve inlet, i.e., where Section C3.16 of
AHRI 1250-2009 requires the measurement to be within 6 pipe diameters
of the control device, DOE proposes to relax this requirement and
require instead that the measurement be within 6 inches of the device.
Issue 14: DOE requests comment on its proposal to allow the use of
two temperature measuring instruments, placed on the outside of
refrigerant tubing that is less than or equal to \1/2\-inch, for the
measurement of refrigerant temperature where the current test procedure
requirement is to use thermometer wells or a sheathed sensor immersed
in the refrigerant.
[[Page 23948]]
3. Hierarchy of Installation Instructions and Specified Refrigerant
Conditions for Refrigerant Charging and Setting Refrigerant Conditions
During testing, DOE has found that some refrigeration systems
cannot be set up fully consistent with the refrigerant conditions
specified in installation instructions. In some cases, there may be
multiple installation instructions (e.g., instructions on labels
affixed to the unit and instructions shipped with the unit), and
different results could be obtained depending on which instructions are
followed. To address this issue, DOE has developed a setup hierarchy
for installation instructions and setup of refrigerant conditions to
improve repeatability in testing by indicating which manufacturer-
specified conditions would be prioritized during test setup. DOE's
proposed setup hierarchy is discussed in more detail in the following
paragraphs.
Setup conditions or instructions may be stamped on the unit
nameplate or otherwise affixed to the unit, shipped with the unit, or
available online. DOE has encountered walk-in refrigeration units for
which these three sources of instruction provide different values or
conflicting directions. To ensure consistent setup during testing, DOE
proposes that instructions or conditions stamped on or adhered to a
test unit take precedence, followed by instructions shipped with the
unit. Additionally, since online instructions can be easily revised,
DOE proposes that instructions or other setup information found online
would not be used to set up the unit for test.
Setting of refrigerant charge level or refrigerant conditions is a
key aspect of setup of refrigeration systems, whether for field use or
testing. DOE proposes that units be charged and set up at operating
conditions specified in the test procedure (for outdoor refrigeration
systems, DOE proposes use of operating condition A) based on the
installation instructions, using the proposed hierarchy (i.e.,
prioritize instructions stamped or adhered to unit over instructions
included in a manual shipped with the unit). In the case where
instructions for refrigerant charging or refrigerant conditions are
provided only in online instructions or not at all, DOE is proposing
that a generic charging approach be used instead. If the installation
instructions specify operating conditions to use to set up the
refrigerant charge or refrigerant conditions, that operating condition
would be used rather than the conditions specified in the test
procedure.
DOE often finds that in some cases, the manufacturer specifies a
range of conditions for superheat,\28\ subcooling, and/or refrigerant
pressure. If this is the case, DOE proposes to treat the midpoint of
that range as the target temperature/pressure, and that a test
condition tolerance would be applied to the parameter that is equal to
half the range. For example, if a manufacturer specifies a target
superheat of 5 to 10 [deg]F, the target for test would be 7.5 [deg]F
and that the average value during operation at the setup operating
conditions would have to be 7.5 [deg]F 2.5 [deg]F.
Alternatively, installation instructions may specify a refrigerant
condition value without a range or without indicated tolerances. In
such cases, DOE proposes that standardized tolerances be applied as
indicated in Table III.6. These tolerances depend on the kind of
refrigerant expansion device used.
---------------------------------------------------------------------------
\28\ Superheat is the difference between vapor-phase refrigerant
temperature and the dew point corresponding to the pressure level.
---------------------------------------------------------------------------
DOE also notes that zeotropic \29\ refrigerants have become more
common. When charging with such refrigerants (i.e., any 400 series
refrigerant), DOE proposes that the refrigerant charged into the system
must be in liquid form. This is standard practice for charging of such
refrigerants since the concentrations of the components of the blend
present in the vapor phase of the charging cylinder are often skewed
from the intended concentrations of the refrigerant blend.
---------------------------------------------------------------------------
\29\ A zeotropic refrigerant is a blend of two or more
refrigerants that have different boiling points. Each refrigerant
will evaporate and condense at different temperatures.
---------------------------------------------------------------------------
If the installation instructions on the label affixed to (or
shipped with) the unit do not provide instructions for setting
subcooling or otherwise how to charge it with refrigerant for a
condensing unit tested alone, or tested as part of a matched pair, DOE
proposes requiring that the unit be tested in a way that is consistent
with the DOE test procedure and the installation instructions and also
does not cause the unit to stop operating during testing, e.g., by
shutoff by the high pressure switch. DOE believes that such
installation would be most representative of the way a technician would
set up a system in the field if there were no refrigerant charge or
subcooling instructions.
a. Dedicated Condensing Unit Charging Instructions
For dedicated condensing units tested alone, subcooling is the
primary setup condition. DOE is proposing that if the dedicated
condensing unit includes a receiver and the subcooling target leaving
the condensing unit provided in the installation instructions cannot be
met without fully filling the receiver, the subcooling target would be
ignored. Likewise, if the dedicated condensing unit does not include a
receiver and the subcooling target leaving the condensing unit cannot
be met without the unit cycling off on high pressure, the subcooling
target would be ignored. Also, if no instructions for charging or for
setting subcooling leaving the condensing unit are provided in the
installation instructions, DOE is proposing that the refrigeration
system would be set up with a charge quantity and/or exit subcooling
such that the unit operates during testing without shutdown (e.g., on a
high-pressure switch) and operation of the unit is otherwise consistent
with the requirements of the test procedure and the installation
instructions.
b. Unit Cooler Charging Instructions
For unit coolers tested alone, superheat is the primary setup
condition. Most WICF refrigeration systems use either thermostatic or
electronic expansion valves that respond either mechanically or through
a controller to adjust valve position to control for superheat leaving
the unit cooler. If the unit under test is shipped with an adjustable
expansion device, DOE proposes that this would be the primary method to
adjust superheat. However, DOE has encountered units with expansion
devices that are not adjustable or where the expansion device does not
provide a sufficient range of adjustment to achieve the superheat
target. If the expansion valve associated with the unit under test
reaches its limit before the superheat target is met, the specified
superheat may not be met within the specified tolerance. In this case,
DOE proposes that the expansion valve should be left at the adjustment
limit achieving the closest match to the superheat target.
DOE has also encountered mis-matched expansion devices and unit
coolers. In this situation, DOE proposes that any expansion device
specified for use with the unit cooler in manufacturer literature may
be used for the purposes of DOE testing.
Also, DOE proposes that an operating tolerance would not apply to
superheat. Hence, in the event that the expansion valve control of the
systems is not steady, i.e., if so-called ``hunting'' occurs, in which
the valve position, temperatures, and/or pressures are unsteady, this
fluctuation would not
[[Page 23949]]
invalidate a test. However, if the fluctuations are so great that a
valid test cannot be performed (i.e., any individual measurement of
superheat during the test is zero or less, or if the operating
tolerances for measurements that would be affected by expansion device
hunting are exceeded (mass flow, pressure at the unit cooler exit,
evaporator temperature difference),\30\ the test procedure would call
for remedial action allowing deviation from the installation
instructions. The remedial action would be, at the discretion of the
test laboratory, replacing the expansion device with a different
expansion device that does not need to be listed in installation
instructions, adjusting the expansion device to provide an average
superheat that is greater than the target superheat, or both.
---------------------------------------------------------------------------
\30\ Evaporator Temperature Difference (TD) is the difference in
temperature between the entering air and the refrigerant dew point
of the exiting refrigerant.
---------------------------------------------------------------------------
If the installation instructions on the label affixed to the unit
or shipped with the unit do not provide instructions for setting
superheat for a unit cooler tested alone or tested as part of a matched
pair, DOE proposes that the target superheat would be 6.5 [deg]F, the
same value required in such circumstances in AHRI 1250-2020 (see
footnotes to Tables 16 and 17 of AHRI 1250-2020).
c. Single-Packaged Dedicated System Setup and Charging Instructions
DOE has identified multiple setup issues while testing single-
packaged dedicated systems. Compared to split refrigeration
systems,\31\ single-packaged dedicated systems have less adjustment
flexibility due to lack of controls. Additionally, many single-packaged
dedicated systems are marketed as ``fully charged''; therefore, it
could be assumed that the charge would not need to be adjusted.
---------------------------------------------------------------------------
\31\ ``Split refrigeration systems'' refer to systems made up of
a condensing unit and a unit cooler that are connected by
refrigerant lines and are not contained in a single housing. Split
refrigeration systems could be field-matched condensing units and
unit coolers or condensing units and unit coolers sold as matched
pairs.
---------------------------------------------------------------------------
DOE proposes that one or more pressure gauges, depending on the
number of conditions which require a pressure measurement for
validation, should be installed during the setup according to
installation instructions to evaluate the charge of the unit under test
and to accurately measure setup conditions. The location of the
pressure gauge(s) would depend on the test setup conditions given in
the installation instructions. If charging is based on subcooling or
liquid pressure, DOE proposes that the pressure gauge would be
installed at the service valve of the liquid line. If charging is based
on superheat, low side pressure, or a corresponding saturation
temperature/dew point temperature, DOE proposes that the pressure
gauge(s) would be placed in the suction line.
DOE is aware that installation instructions for some single-
packaged dedicated systems recommend against installing charging ports;
however, DOE has observed through testing that some of these units do
not operate once installed due to high- or low-pressure compressor cut
off, which is often a symptom of under- or over-charging or refrigerant
loss. These units are representative of what a contractor would
encounter when installing a walk-in single-packaged unit in the field.
Therefore, in cases where a unit under test is not operating due to
high- or low-pressure compressor cut off, DOE proposes a charging port
should be installed, the unit should be evacuated, and the nameplate
charge should be added. This approach would eliminate under- or over-
charging of the unit which would address compressor cut off.
d. Hierarchy of Setup Conditions if Manufacturer-Specified Setup
Conditions Cannot be Met
In DOE's experience, even when all the previously discussed
measures are implemented during test setup, some manufacturer specified
setup conditions may not be met. If this is the case, DOE is proposing
that the unit under test be set up according to a hierarchy of
conditions similar to those used for central air-conditioning systems
and heat pumps. First, the installation instruction hierarchy
previously discussed would be applied. Specifically, if a refrigerant-
related setup instruction in the installation instructions affixed to
the unit and a different instruction in the installation instructions
shipped with the unit cannot both be achieved within tolerance, the
instruction on the label takes precedence. Further, if multiple
instructions within the relevant installation instructions cannot be
met, the proposed hierarchy outlined in Table III.6 would be applied.
The highest priority condition that can be satisfied, based on Table
III.6, would need to be met, depending on what kind of expansion device
the system uses. This approach would ensure that units are set up
consistently across testing facilities, ensuring more consistent
results.
Table III.6--Test Condition Tolerances and Hierarchy for Refrigerant Charging and Setting of Refrigerant
Conditions
----------------------------------------------------------------------------------------------------------------
Fixed orifice or capillary tube Expansion valve
----------------------------------------------------------------------------------------------------------------
Priority Method Tolerance Priority Method Tolerance
----------------------------------------------------------------------------------------------------------------
1 Superheat....... 2.0 [deg]F... 1 Subcooling..... 10% of the
Target Value;
No less than
0.5
[deg]F, No
more than
2.0
[deg]F.
2 High Side 4.0 psi or 2 High Side 4.0
Pressure or 1.0 [deg]F. Pressure or psi or 1.0
Temperature. Temperature. [deg]F.
3 Low Side 2.0 psi or 3 Superheat...... 2.0
Pressure or 0.8 [deg]F. [deg]F.
Saturation
Temperature.
4 Low Side 2.0 [deg]F... 4 Low Side 2.0
Temperature. Pressure or psi or 0.8
Temperature. [deg]F.
5 High Side 2.0 [deg]F... 5 Approach 1.0
Temperature. Temperature. [deg]F.
6 Charge Weight... 2.0 oz....... 6 Charge Weight.. 0.5% or 1.0 oz,
whichever is
greater.
----------------------------------------------------------------------------------------------------------------
[[Page 23950]]
Issue 15: DOE requests comment on its proposals discussed in this
section regarding set up of walk-in refrigeration systems for testing
to achieve manufacturer-specified conditions for superheat, subcooling,
high-side temperature, pressure or saturation temperature, low-side
temperature, pressure or saturation temperature, and refrigerant charge
weight. Additionally, DOE requests comment on the proposed hierarchy
presented in Table III.6, if a laboratory has confirmed that the unit
is properly charged.
4. Subcooling Requirement for Mass Flow Meters
DOE has found that for testing dedicated condensing units alone an
appropriate subcooling temperature ensures that the refrigerant is
fully liquid at the mass flow meter, providing an accurate measurement.
A mass flow meter may provide an inaccurate flow rate if the
refrigerant is a mixture of vapor and liquid at the point of
measurement. Section C3.4.5 of AHRI 1250-2009 appendix C requires that
refrigerant be subcooled to at least 3 [deg]F and that bubbles not be
visible in a sight glass immediately downstream of the mass flow meter.
Section 3.2.3 of subpart R, appendix C, allows use of the sight glass
and a temperature sensor located on the tube surface under the
insulation to verify sufficient subcooling. DOE testing has also shown
that even when the subcooling requirement is met downstream of the mass
flow meters, the subcooling can be significantly lower upstream of the
mass flow meters, resulting in questionable mass flow measurements that
do not provide capacity determinations within the required tolerances,
e.g., with 5 percent of each other as required by Section C8.5.3 of
AHRI 1250-2009 (see EERE-2017-BT-TP-0010-0021, ``Development of Test
Rating Conditions for Two-Capacity, Multiple-Capacity, and Variable-
Capacity Condensing Units''). DOE proposes to add further instruction
to section 3.2.3 of subpart R, appendix C.
First, DOE proposes that the 3 [deg]F subcooling requirement be
applied at a location depending on location of the liquid-line mass
flow meters. Specifically, the requirement would apply downstream of
any mass flow meter located in the chamber in which the condensing unit
under test is located, consistent with AHRI 1250-2009. However, for
mass flow meters located in the chamber in which the unit cooler under
test is located, the subcooling would have to be verified upstream of
the mass flow meter. The latter requirement addresses observation in
DOE testing that the upstream subcooling is less than the downstream
subcooling when the mass flow meter is in the same chamber as the unit
cooler. Id. This occurs because the unit cooler chamber is generally
much cooler than the liquid refrigerant.\32\ Since mass flow meters are
rarely insulated, the liquid refrigerant is cooled as it passes through
the mass flow meter, which increases the refrigerant's subcooling.
However, as the liquid refrigerant passes through the mass flow meter
it also experiences a pressure drop which decreases the subcooling. The
increase in subcooling that occurs across the mass flow meter is nearly
always larger than the decrease in subcooling that occurs because of
the pressure drop across the mass flow meter. Therefore, subcooling
will nearly always be less at the inlet of a mass flow meter than at
the outlet. This is in contrast to a mass flow meter located in the
same chamber as the condensing unit, for which the air surrounding the
mass flow meter, while typically cooler than the liquid, would be much
closer in temperature to the liquid temperature.\33\ DOE also notes
that the requirement for subcooling specified in ASHRAE 23.1-2010,
which is incorporated by reference by the DOE test procedure for
testing of condensing units alone, indicates in section 7.1.2
(``Adequate subcooling shall be provided upstream of a liquid
refrigerant flowmeter . . .'') suggesting that there is a lack of
clarity regarding the best location for ensuring adequate subcooling.
Based on DOE's experience and the prevailing air-liquid temperature
differences during testing, DOE proposes to include the clarification
above regarding the location of the subcooling verification.
---------------------------------------------------------------------------
\32\ For example, when testing a matched pair refrigerator
system under test condition A, the condensing unit chamber air
temperature is at 95 [deg]F and the unit cooler chamber air is at 35
[deg]F. The liquid refrigerant generally is warmer than the
condensing unit ambient temperature. Hence, there is at least a 60
[deg]F temperature difference between the unit cooler inlet air
temperature and the liquid refrigerant temperature.
\33\ For the same example, the liquid temperature may be in the
range roughly from 95 [deg]F to 105 [deg]F, at most about 10 [deg]F
warmer than the surrounding air.
---------------------------------------------------------------------------
Second, DOE proposes to indicate that active cooling of the liquid
line may be used to achieve the required subcooling, since the
subcooling at the mass flow meter outlet may not meet the 3 [deg]F
requirement when the subcooling at the condensing unit exit is within
tolerance of its target. However, DOE also proposes requiring that if
this is done when testing a matched pair (not including single-packaged
dedicated systems), that the temperature also must be measured upstream
of the location where cooling is provided, and that the temperature
used to calculate the enthalpy of the refrigerant entering the unit
cooler be increased by the difference between the upstream and
downstream measurements. DOE is proposing this adjustment so that
active cooling of the liquid to obtain a mass flow measurement does not
provide a non-representative boost in calculated cooling capacity.
DOE proposes to add these requirements to subpart R, appendix C,
which would also carry over to the newly proposed subpart R, appendix
C1.
Issue 16: DOE requests comments on its proposal to clarify the
location where the 3 [deg]F subcooling requirement would apply and to
require active cooling of the liquid line in order to achieve the
required 3 [deg]F subcooling at a refrigerant mass flow meter. DOE also
seeks comment on its proposal to require, for matched pairs, adjustment
of the measured unit cooler inlet temperature by the difference in
temperatures measured upstream and downstream of the active cooling in
order to calculate the inlet enthalpy in the capacity calculation.
5. Instrument Accuracy and Test Tolerances
As discussed in section III.B.3.a, AHRI 1250-2020 has adopted
language from the current DOE test procedure covering test tolerances
and instrumentation accuracy. Additionally, as discussed in section
III.B.3.d, some tolerances and instrumentation accuracy requirements in
AHRI 1250-2020 are not consistent with the current DOE test procedure.
DOE is proposing to adopt these changes from AHRI 1250-2020 into
subpart R, appendix C, as DOE has tentatively determined these changes
would not have an effect on measured values.
AHRI 1250-2020 changes the measurement accuracy for the temperature
of air entering or leaving either the evaporator or condenser to 0.25 [deg]F from 0.2 [deg]F in AHRI 1250-2009. DOE
notes that 0.25 [deg]F is the standard minimum accuracy
across many Heating, Ventilation and Air-Conditioning (``HVAC'')
testing standards. Since AHRI 1250-2020 references AHSRAE 37-2009 for
single-packaged testing, it simplifies the test procedure to have the
same instrument accuracy requirements across both standards. In
addition, providing a consistent minimum accuracy across test
procedures reduces laboratory test burden and DOE expects it may
benefit a laboratory's quality control. DOE is
[[Page 23951]]
proposing that the temperature measurement of air entering or leaving
either the compressor or evaporator would have a minimum accuracy of
0.25 [deg]F. DOE does not expect this modification to have
a significant impact on measured values. Additionally, the proposed
tolerance is greater than the current tolerance and therefore if
adopted it would not require manufacturers to retest. DOE does not
expect that the changed tolerance would impact the representativeness
of the results. As noted, the proposed tolerance is that generally used
for HVAC systems.
As discussed in section III.B.3.d, AHRI 1250-2020 does not
reference ASHRAE 23 or AHRI 420 for the testing of dedicated condensing
units and unit coolers, respectively. As such, the ASHRAE 23
refrigerant mass flow operating tolerance of one percent
of the quantity measured has been replaced in Table 2 of AHRI 1250-2020
by an operating tolerance of 3 pounds per hour (``lb/h'') or 2 percent
of the reading (whichever is greater). DOE notes that the requirement
for a one percent mass flow tolerance posed challenges for test labs
when at very low flow rates (near 0 lb/h). Specifically, as mass flow
approaches 0 lb/h, the acceptable deviation from the average also
approaches zero resulting in an unrealistic accuracy target. This issue
would not occur with the minimum accuracy provided in AHRI 1250-2020
because the acceptable deviation from the average must be within 3 lb/h if the variation is less than 2 percent of the mass flow
reading. As such, DOE is proposing to adopt the mass flow tolerance
specified in Table 2 of AHRI 1250-2020 into subpart R, appendix C. DOE
does not expect that this modification would have a significant impact
on capacity and AWEF values, and therefore would not require retesting
or recertification.
6. CO2 Unit Coolers
All refrigerants have a ``critical pressure'' and an associated
``critical temperature'' above which liquid and vapor phases cannot
coexist. Above this critical point, the refrigerant will be a gas and
its temperature will increase or decrease as heat is added or removed.
For all conventional refrigerants, the critical pressure is so high
that it is never exceeded in typical refrigeration cycles. For example,
R404A is a common refrigerant used in refrigeration systems that has a
critical pressure of 540.8 psia \34\ with an associated critical
temperature of 161.7 [deg]F. However, CO2 behaves
differently, with a critical pressure of 1,072 psia associated with a
lower critical temperature of 87.8 [deg]F. The refrigerant temperature
must be somewhat higher than the ambient temperature in order to reject
refrigeration cycle heat to the ambient environment. Ambient
temperatures greater than 87.8 [deg]F are common and the performance of
many refrigeration and air conditioning systems are tested using a 95
[deg]F ambient temperature, as indicated by the A test condition in
Section 5 of AHRI 1250-2009 (and AHRI 1250-2020). At temperatures
greater than the critical temperature, the CO2 refrigerant
is in a supercritical state (i.e., a condition with pressure above the
critical temperature). Since useful cooling is provided below the
critical temperature, CO2 cycles are said to be
transcritical.
---------------------------------------------------------------------------
\34\ Absolute pressure is the pressure measured relative to a
complete vacuum; ``psia'' represents the absolute pressure in pounds
per square inch.
---------------------------------------------------------------------------
DOE has granted test procedure waivers to the manufacturers listed
in Table III.1 for certain basic models of walk-in refrigeration
systems that use CO2 as a refrigerant. Manufacturers
requesting a waiver from the DOE test procedure for CO2 unit
coolers stated that the test conditions described in Tables 15 and 16
of AHRI 1250-2009, as incorporated by subpart R, appendix C, with
modification, cannot be achieved by, and are not consistent with the
operation of, CO2 direct expansion unit coolers. These
manufacturers also specified that CO2 has a critical
temperature of 87.8 [deg]F, and therefore the required liquid inlet
saturation temperature of 105 [deg]F and the required liquid inlet
subcooling temperature of 9 [deg]F as specified in the DOE test
procedure are not achievable. The alternate test procedure provided in
these waivers modifies the test condition values to reflect typical
operating conditions for a transcritical CO2 booster system.
Specifically, the waiver test procedures require that CO2
unit cooler testing is conducted at a liquid inlet saturation
temperature of 38 [deg]F and a liquid inlet subcooling temperature of 5
[deg]F. CO2 that is cooled in the gas cooler of a
transcritical booster system expands through a high-pressure control
valve that delivers CO2 to a subcritical-pressure flash
tank, where liquid and vapor phases of the refrigerant are separated.
The liquid is then split, and the unit cooler, regardless of
refrigerated storage space temperature, receives the refrigerant at the
same condition. This applies to both medium- and low-temperature
systems.
In the June 2021 RFI, DOE requested comment on whether the test
conditions provided in the waivers are appropriate and if there are
additional modifications that could more accurately evaluate the energy
use of these systems while minimizing test burden. 86 FR 32332, 32346.
Lennox, AHRI, National Refrigeration, and Hussmann recommended that DOE
use the conditions provided in the waivers for CO2 unit
coolers. (Lennox, No. 9 at p. 7; AHRI, No. 11 at p. 12; National
Refrigeration, No. 17 at p. 1; Hussmann, No. 18 at p. 14)
In the June 2021 RFI, DOE also requested comment on the present and
future expected use of CO2 systems and information about
such systems that would suggest a need to modify the DOE test
procedure. 86 FR 32332, 32346. Lennox, AHRI, and Hussmann stated that
some CO2 units, not available in the U.S., may supply
subcritical liquid or supercritical gas at the expansion valve, while
some condensing units with integrated expansion valves supply two-phase
CO2 to evaporators. (Lennox, No. 9 at pp. 7-8; AHRI, No. 11
at pp. 12-13; Hussmann, No. 18 at p. 14) For units where the
CO2 leaving the condensing unit is supercritical or two-
phase, Lennox, AHRI, and Hussmann recommended setting temperature and
pressure conditions; for condensing units providing subcritical liquid
to unit cooler expansion devices, these stakeholders suggested that the
test method provided in the waivers should be used. (Lennox, No. 9 at
p. 8; AHRI, No. 11 at p. 13; Hussmann, No. 18 at p. 14) Lennox, AHRI,
and Hussmann additionally stated that while CO2 condensing
units with a single compression stage and conventional HFC units can be
tested using the same method, an intermediate pressure that is the same
as the liquid supply conditions in the waiver test procedures must be
specified for units with two stages of compression. Id. Lennox
recommended evaluating the potential energy savings of CO2
units to see if additional changes are warranted. (Lennox, No. 9 at p.
7) The CA IOUs suggested that DOE differentiate AWEF ratings of units
using CO2 and units using traditional refrigerants. (CA
IOUs, No. 14 at p. 4) Additionally, the CA IOUs urged DOE to ensure
that the walk-in test procedures and metrics continue to provide
consumers with the information necessary to easily compare the
performance of products with the same utility. Id.
DOE acknowledges that a goal of its test procedures is to provide
purchasers
[[Page 23952]]
with an energy use metric that is consistent across products that
provide similar utility. In response to the comment by Lennox, DOE
would evaluate the potential energy savings of CO2 units as
part of a separate, future energy conservation standards rulemaking.
DOE investigation confirms that there are no known sales of
CO2 dedicated condensing units in the U.S. The only relevant
CO2 system architecture in the U.S. appears to be
CO2 booster systems using unit coolers operating with
conditions consistent with the waivers.
DOE also evaluated if the current AWEF calculation for unit coolers
tested alone could be applied to CO2 unit coolers. The
current calculation uses an EER to determine the representative
compressor power consumption. The EER values used are in Table 18 of
AHRI 1250-2020 and are based on typical traditional refrigerant
compressor efficiency. DOE has tentatively determined that the EER
values used for the AWEF calculations of traditional unit coolers can
also be used for CO2 unit coolers. DOE research into the
performance of different configurations of CO2 booster
systems shows that enhanced CO2 cycles can match
conventional refrigerants in average annual efficiency. These data and
studies help to justify the use of the EER values in Table 18 of AHRI
1250-2020 for determining the power consumption of CO2
booster system unit coolers, even though these EER values were
initially established for conventional refrigerants.
In this NOPR, DOE is proposing to adopt in subpart R, appendix C
(and also appendix C1), the alternate test conditions specified in the
waivers that DOE granted for CO2 transcritical unit coolers
for all CO2 unit coolers. Also, consistent with the waiver
alternate test procedures, DOE proposes that the established EER values
be used to determine compressor power found in Table 17 of AHRI 1250-
2009 (or Table 18 of AHRI 1250-2020 for appendix C1) would be used to
determine the AWEF of all CO2 unit coolers.
Issue 17: DOE requests comment on the appropriateness of
traditional refrigerant compressor EER values for use in CO2 unit
cooler AWEF calculations.
7. High-Temperature Unit Coolers
As discussed in the June 2021 RFI, DOE is aware of wine cellar
(high-temperature) refrigeration systems that fall within the walk-in
definition but that may be incapable of being tested in a manner that
would yield representative performance results during a representative
average use cycle under the current version of the walk-in test
procedure. 86 FR 32332, 32344. For example, wine cellar refrigeration
systems that may be installed in some commercial settings are designed
to operate at a temperature range of 45 [deg]F to 65 [deg]F.
High-temperature refrigeration systems are discussed generally in
section III.G.6. Most of these refrigeration systems are either a
single-packaged dedicated system or a matched pair. However, DOE has
also received a petition for waiver for high-temperature unit coolers
that are distributed into commerce without a paired condensing
system.\35\ These unit cooler-only models would be tested according to
the provisions in the test procedure for unit coolers tested alone, for
which calculation of AWEF requires use of an appropriate EER based on
the suction dew point temperature. Table 17 in AHRI 1250-2009 provides
EER values for medium- and low-temperature unit coolers tested alone.
However, DOE has tentatively determined that these values are not
appropriate for calculating AWEF for high-temperature unit coolers
because this equipment operates with a different suction dew point
temperature and the counterpart dedicated condensing units likely use
different compressor designs than those considered when developing the
EER values included in AHRI 1250-2020.
---------------------------------------------------------------------------
\35\ LRC Coil Company submitted a petition for waiver and
interim waiver for specific basic models of unit cooler only walk-in
wine cellar refrigeration systems. (LRC Coil, EERE-2020-BT-WAV-0040,
No. 1) In reviewing another petition for waiver and interim waiver
from Vinotheque for single-packaged system and matched pair system
basic models (Vinotheque, EERE-2019-BT-WAV-0038, No. 6), DOE noted
that the manufacturer also offered unit cooler-only systems
distributed without a paired condensing system.
---------------------------------------------------------------------------
In the June 2021 RFI, DOE requested data on appropriate EER values
for use with high-temperature unit coolers and questioned how these
values might depend on refrigerant or capacity. 86 FR 32332, 32345.
AHRI stated that they did not have data to support EER values for use
in determining AWEF for wine cellar unit coolers since most systems are
sold as a matched pair. (AHRI, No. 11 at p. 11) In the June 2021 RFI,
DOE also requested information on dedicated condensing units that would
typically be paired with high-temperature unit coolers. 86 FR 32332,
32345-32346. Lennox and AHRI stated that there are no definitive
characteristics for unit coolers that are sold for use in wine cellar
refrigeration applications, and that many units are sold to users as
pairs matched by contractors. (Lennox, No. 9 at pp. 6-7; AHRI, No. 11
at pp. 11-12)
In its market evaluation, DOE has observed that a majority of high-
temperature refrigeration systems are sold as matched pairs or single-
packaged systems. While unit coolers sold for high-temperature walk-in
cooler applications are sold separately, DOE was unable to find any
dedicated condensing units marketed specifically for high-temperature
walk-in applications. Thus, DOE could not use the performance data of
such dedicated condensing unit models to provide an indication of the
appropriate EER for dedicated condensing units paired with such high-
temperature unit coolers. Rather, consistent with the interim waiver
granted to LRC, DOE is proposing EER values developed using compressor
performance data from Emerson and Tecumseh product websites (EERE-2020-
BT-WAV-0040, No. 2 and No. 8, respectively) for high-temperature
refrigeration compressor models within the applicable capacity range
(2,900 Btu/h to 36,000 Btu/h). DOE expects that the dedicated
condensing units paired with high-temperature walk-in unit coolers
would use hermetic reciprocating compressors at lower capacities and
hermetic scroll compressors at higher capacities. Also, DOE developed
the EER values based on compressors rated for use with HFC-134a, R404A,
or R407C refrigerants. Based on these compressor performance data, DOE
calculated representative compressor EER levels for wine cellar walk-in
unit coolers using the following parameters:
38 [deg]F unit cooler exit dew point condition, as
suggested by LRC (EERE-2020-BT-WAV-0040, No. 1 at p. 3).
2 [deg]F equivalent suction line dew point pressure drop,
consistent with AHRI 1250-2009 section 7.9.1.
7 [deg]F evaporator exit superheat, rounding to whole
number values of the 6.5 [deg]F superheat test condition prescribed in
the footnote to Table 15 of subpart R, appendix C, in case a value is
not provided in an installation manual.
55 [deg]F refrigerant temperature entering the compressor,
representing a 10 [deg]F refrigerant vapor temperature rise in the
suction line, consistent with the temperature rise implied for medium-
temperature refrigeration system test conditions.\36\
---------------------------------------------------------------------------
\36\ AHRI 1250-2009 Table 11 prescribes a return gas temperature
(measured at the condensing unit inlet location) equal to 41 [deg]F
for testing medium temperature dedicated condensing units. Also,
Table 15 and section 3.3.1 of appendix C prescribe testing medium-
temperature unit coolers using 25 [deg]F saturated suction
temperature (this is the same as unit cooler exit dew point
temperature), and 6.5 [deg]F superheat (in case the installation
manual doesn't provide superheat requirements). Thus, the unit
cooler exit temperature would be 25 [deg]F + 6.5 [deg]F = 31.5
[deg]F, and the implied suction line temperature rise is 41 [deg]F-
31.5 [deg]F = 9.5 [deg]F. The analysis conducted for wine cellars
rounds this to 10 [deg]F.
---------------------------------------------------------------------------
[[Page 23953]]
90 [deg]F annual average condensing temperature. This
assumes that the condensing unit serving the unit cooler would be
located outdoors and that head pressure control would prevent
excessively cold condensing operation at cold outdoor temperatures.\37\
---------------------------------------------------------------------------
\37\ ``Head pressure control'' refers to the reduction of
condenser heat transfer performance using fan cycling or other means
when it is cold outside in order to avoid unusually low condensing
temperature. Such low condensing temperatures are undesirable
because they can reduce refrigeration system performance and/or
increase risk of compressor damage. A typical minimum condensing
temperature is 70 [deg]F, which may apply whenever outdoor
temperature is lower than 50 [deg]F. DOE selected the 90 [deg]F
annual average to be representative of operation that would involve
condensing temperature ranging from 70 [deg]F to 120 [deg]F, since
outdoor temperature varies.
---------------------------------------------------------------------------
DOE plotted the calculated compressor EER values versus calculated
unit cooler capacity and noted that the EER can significantly vary with
capacity. (EERE-2020-BT-WAV-0040, No. 9) EER is generally lower for
low-capacity compressors and higher for high-capacity compressors, with
a transition region in between. Based on the plotted calculations, DOE
determined for the purpose of the interim waiver that a representative
value for EER should depend on capacity. As such, DOE developed
different functions of EER for three distinct capacity ranges. Table
III.7 summarizes these capacity ranges and EER functions for high-
temperature compressors.
Table III.7--EER Values for High Temperature Compressors as a Function
of Capacity for High-Temperature Refrigeration Systems
------------------------------------------------------------------------
Capacity (Btu/hr) EER (Btu/Wh)
------------------------------------------------------------------------
<10,000................................... 11
10,000-19,999............................. (0.0007 x Capacity) + 4
20,000-36,000............................. 18
------------------------------------------------------------------------
The LRC interim waiver includes additional test procedure
provisions to obtain representations that are representative for high-
temperature unit coolers, including both testing requirements and AWEF
calculation requirements. These include provisions for setting ducted
fan-coil unit evaporator systems.
DOE proposes to include provisions for testing high-temperature
unit coolers in subpart R, appendix C. These provisions, consistent
with the LRC interim waiver, would include test conditions for testing
these unit coolers at high-temperature refrigeration conditions, as
well as EER values described previously for calculation of AWEF. DOE
also proposes to include these provisions in appendix C1.
Issue 18: DOE requests comment on its proposals to adopt test
procedure provisions for high-temperature unit coolers in appendices C
and C1 of 10 CFR part 431, subpart R.
G. Proposal To Establish Appendix C1
In this NOPR, DOE is proposing to establish a new appendix C1 to
subpart R of part 431, which would be required to demonstrate
compliance coincident with the compliance date of any amended energy
conservation standards that DOE may promulgate as part of a separate
standards rulemaking. Certain proposed modifications to the test
procedure are expected to alter measured values, and such changes are
contained in the proposed appendix C1. DOE has tentatively determined
that AHRI 1250-2020 improves representativeness of the walk-in
refrigeration system test procedure by incorporating off-cycle
measurement for components in addition to off-cycle fan power and
providing test options for single-packaged dedicated systems, in
addition to other changes. Therefore, DOE is proposing to incorporate
AHRI 1250-2020 by reference into its proposed test procedure at
appendix C1 for walk-in refrigeration systems.
Lennox, AHRI, Keeprite, National Refrigeration, and Hussmann
commented in response to the June 2021 RFI, that adopting the changes
to AHRI 1250-2020 in the DOE test procedure would result in different
energy consumption measurements. (Lennox, No. 9 at p. 2; AHRI, No. 11
at p. 4; Keeprite, No. 12 at p. 1; National Refrigeration, No 17 at p.
1; Hussmann, No. 18 at p. 6) DOE has tentatively determined that
certain changes in AHRI 1250-2020, if adopted in DOE's test procedure,
would impact measured values as compared to the current DOE test
procedure. As discussed in the following paragraphs, DOE proposes to
adopt such provisions in the newly proposed appendix C1 through refence
to AHRI 1250-2020 and proposes that appendix C1 would not be required
for testing until such time as compliance is required with amended
energy conservation standards for walk-ins that are based on testing
according to appendix C1, should DOE adopt such standards.
The test procedure changes that DOE proposes to include in a newly
proposed appendix C1 are discussed in the following sections. DOE
expects these changes to improve the representativeness and
applicability of the test procedure for walk-in refrigeration systems.
1. Off-Cycle Power Consumption
For walk-in refrigeration systems, the term off-cycle refers to the
period when the compressor is not running and defrost (if applicable)
is not active. During off-cycle, unit cooler fans and other auxiliary
equipment (i.e., crankcase heater, receiver heater, etc.) \38\ may
typically run or cycle on and off, consuming energy. The DOE test
procedure currently accounts for only unit cooler fan energy use during
the off-cycle period. 10 CFR part 431, subpart R, appendix C, section
3.3.3. Specifically, the current test procedure requires manufacturers
to measure the integrated average off-cycle fan wattage \39\ for
matched pair and unit coolers tested alone. Dedicated condensing units
tested alone use default fan energy values rather than tested values.
10 CFR part 431, subpart R, appendix C, section 3.4.2.2. When
calculating AWEF, the unit cooler fans are assumed to run at this
average integrated wattage throughout the entire off-cycle duration.
Id.
---------------------------------------------------------------------------
\38\ A crankcase heater prevents refrigerant migration and
mixing with the crankcase oil when the compressor is off by heating
the crankcase of the compressor. A receiver heater warms refrigerant
in the receiver to prevent flooded starts of the compressor and
cycling on low pressure to reduce the potential for compressor
damage. They are used for outdoor dedicated condensing units in
colder climates.
\39\ Fans using periodic stir cycles are tested at the greater
of a 50% duty cycle or the manufacturer default. Fans with two,
multi-, or adjustable-speed controls are tested at the greater of
50% fan speed or the manufacturer's default fan speed. Fans with no
controls are tested at their single operating point. (See 10 CFR
part 431, subpart R, appendix C, section 3.3.3).
---------------------------------------------------------------------------
In the June 2021 RFI, DOE discussed the recommendations of the
ASRAC Working Group (See Docket No. EERE-2015-BT-STD-0016, No. 56,\40\
Recommendation #6) to revise the off-cycle test procedure to account
for all other components that consume energy during the off-cycle, such
as pan heaters, crankcase heaters, and controls. 86 FR 32332, 32348.
DOE noted that AHRI 1250-2020 includes a method for determining energy
consumption during
[[Page 23954]]
off-cycle for many of these components and DOE discussed the
possibility of incorporating the updated industry test method into a
test procedure. In response to the June 2021 RFI, the CA IOUs supported
the prioritization of ASRAC Term Sheet recommendation #6. (CA IOUs, No.
14 at p. 1-2)
---------------------------------------------------------------------------
\40\ Appliance Standards and Rulemaking Federal Advisory
Committee Refrigeration Systems Walk-in Coolers and Freezers Term
Sheet, available at www.regulations.gov/document?D=EERE-2015-BT-STD-0016-0056.
---------------------------------------------------------------------------
DOE requested comment on the representativeness and repeatability
of the off-cycle test procedure in AHRI 1250-2020. 86 FR 32332, 32348.
Keeprite and National Refrigeration both stated that the off-cycle
power measurement in AHRI 1250-2020 is accurate. (Keeprite, No. 12 at
p. 2; National Refrigeration, No. 17 at p. 2) Lennox, AHRI, ASAP, and
Hussmann supported using the off-cycle power measurements in AHRI 1250-
2020. (Lennox, No. 9 at p. 9; AHRI, No. 11 at p. 14; ASAP, No. 13 at p.
2; Hussmann, No. 18 at p. 17) Keeprite and National Refrigeration
asserted that adopting the off-cycle power measurements in AHRI 1250-
2020 would increase test burden without significant efficiency gains.
(Keeprite, No. 12 at p. 3; National Refrigeration, No 17 at p. 2) NEEA
commented that AHRI 1250-2020 captures off cycle energy consumption
more fully but does not appear to account for start up or shutdown
variation. (NEEA, No. 16 at p. 2)
Also, in the June 2021 RFI, DOE sought feedback on whether there
were additional walk-in refrigeration system components that consume
energy while the unit is in off-cycle mode, which AHRI 1250-2020 does
not address. 86 FR 32332, 32348. DOE did not receive comments on this
topic.
In the June 2021 RFI, DOE additionally requested comment on the
magnitude of off-cycle energy use for each component. Id. DOE did not
receive comments on this topic.
DOE acknowledges that adopting the off-cycle power measurements in
AHRI 1250-2020 may incrementally increase test time; however, obtaining
off-cycle power measurements would account for less than 10 percent of
the overall setup and test duration for walk-in refrigeration systems.
In its testing, DOE has found that the additional energy use measured
using the off-cycle power measurements in AHRI 1250-2020 can be up to
60% more than the off-cycle power measurements in the current test
procedure, indicating that the current test procedure does not fully
represent off-cycle power use for walk-in refrigeration systems.
Therefore, DOE proposes adopting the off-cycle procedure in sections
C3.5, C4.2, and Table C3 in AHRI 1250-2020.
In the following sections (III.F.1.a through III.F.1.d), DOE
presents in more detail its proposals to modify the off-cycle test
method and metric.
a. Off-Cycle Test Duration and Repetition
DOE proposes revising the off-cycle test procedure to account for
all other components (beyond evaporator fans) that consume energy
during the off-cycle, including, but not limited to pan heaters,
crankcase heaters, and controls (collectively, ``ancillary
equipment''). To account for this energy, DOE proposes adopting the
off-cycle power measurements in sections C3.5, C4.2, and Table C3 in
AHRI 1250-2020. This method is generally consistent with the current
DOE test method used to account for off-cycle evaporator fan power;
however, DOE proposes adopting AHRI 1250-2020 in order to properly
account for the energy use of ancillary equipment.
Specifically, AHRI 1250-2020 includes two off-cycle test durations:
One for evaporator fans and ancillary equipment with controls that are
time-varying or respond to ambient or refrigerant temperatures (e.g., a
crankcase heater or fan cycling control), and one for evaporator fans
and ancillary equipment without such controls. For the former, AHRI
1250-2020 requires a 30-minute test. DOE expects that 30 minutes is the
shortest duration that can effectively capture the cyclic and time-
varying energy use that may occur for equipment with controls--thus,
this duration balances the need to minimize test burden with the need
for an accurate and representative test method. For units lacking such
controls, AHRI 1250-2020 requires a test cycle duration of 5 minutes.
In the absence of controls, DOE expects the off-cycle integrated power
to be constant over time; consequently, DOE is proposing the shorter 5-
minute duration, which would minimize test burden, while still
providing results representative of off-mode energy consumption.
AHRI 1250-2020 also has two sets of test repetition requirements:
One for evaporator fans and ancillary equipment with controls that are
time-varying or respond to ambient or refrigerant temperatures (e.g., a
crankcase heater or fan cycling control), and one for evaporator fans
and ancillary equipment without such controls. For the former, AHRI
1250-2020 requires that the off-cycle test for each applicable load
point \41\ would consist of three initial test cycles, with the
potential for three supplemental cycles. DOE anticipates that at least
three cycles are needed to determine if the measured integrated off-
cycle power is representative of typical operation because the cyclic
operation of evaporator fan and ancillary equipment controls has the
potential to introduce a significant level of test-to-test variability.
Specifically, AHRI 1250-2020 states that if the integrated power for
each of the first three cycles is within 2 percent of the average of
the first three cycles, then off-cycle power would be calculated as the
average of the first three cycles. This requirement reduces test burden
if the unit under test shows repeatable performance. If the 2 percent
requirement is not met, DOE proposes running three supplemental cycles
to provide an opportunity for the unit's controls to exhibit repeatable
behavior. Specifically, AHRI 1250-2020 states that if the integrated
power for each of the three supplemental cycles is within 2 percent of
the average of the three supplemental cycles, then off-cycle power
would be calculated as the average of the three supplemental cycles--
this follows the same rationale as the three initial test cycles. DOE
expects that continuing to test the unit beyond a total of six cycles
would be ineffectual and overly burdensome, as the previous two rounds
of testing would show that stable test-to-test integrated power
readings are unlikely. In the absence of stability, AHRI 1250-2020
requires off-cycle power to be calculated as the maximum of all six
integrated power readings. This requirement is appropriate since it
provides a conservative estimate of integrated off-cycle.
---------------------------------------------------------------------------
\41\ Off-cycle load points are discussed later in this section.
---------------------------------------------------------------------------
Alternatively, for equipment lacking evaporator fans and ancillary
equipment controls, AHRI 1250-2020 requires a single cycle to measure
integrated power. In the absence of controls, DOE expects the off-cycle
integrated power to be constant from cycle-to-cycle; consequently, DOE
is proposing the single-cycle test for units without ancillary power
controls. DOE has preliminarily determined that this approach would
minimize test burden, while providing results representative of off-
mode energy consumption. A summary of test durations and fan settings
based on fan control configuration and ancillary equipment control
configuration is listed in Table III.8.
[[Page 23955]]
Table III.8--Proposed Off-Cycle Test Settings and Durations
----------------------------------------------------------------------------------------------------------------
Ancillary equipment
Fan control configuration control configuration Fan setting for test Test duration
----------------------------------------------------------------------------------------------------------------
No Control........................... No Control............. Default setting, as 5 minutes.
shipped.
No Control........................... With Control........... Default setting, as 30 minutes.
shipped.
User-Adjustable Speed Controls....... No Control............. The greater of 50% fan 5 minutes.
speed or the
manufacturer's default
fan speed.
User-Adjustable Speed Controls....... With Control........... The greater of 50% fan 30 minutes.
speed or the
manufacturer's default
fan speed.
User-Adjustable Stir Cycles.......... With or Without Control The greater of a 50% The greater of 30
duty cycle or the minutes or three full
manufacturer default. ``stir cycles.''
Non-User Adjustable Controls......... With or Without Control Default setting, as 30 minutes.
shipped.
----------------------------------------------------------------------------------------------------------------
b. Off-Cycle Operating Tolerances and Data Collection Rates
DOE proposes to adopt the off-cycle power measurements in Section
C3.5 of AHRI 1250-2020 to establish off-cycle-specific operating test
tolerances. AHRI 1250-2020 excludes the first 10 minutes that follow
the termination of the compressor on-cycle interval from the general
operating tolerances (indoor/outdoor temperatures and power readings)
established for the on-cycle steady state test. During this time
period, the test room conditioning equipment is transitioning from
steady state on-cycle operation into off-cycle operation and the
evaporator coil will continue to remove heat from the inside room air
until temperature equilibrium between the coil and the air is reached.
This non-steady state operation following the on-cycle creates an
environment that is temporarily difficult to control; consequently, DOE
expects that the suspension of steady state tolerances during the
transition period would not impact the representativeness of the test,
since this non-steady state operation is representative of real-world
performance during the transition period.
DOE also proposes to establish off-cycle-specific data collection
rates by adopting the off-cycle power measurements approach provided in
Section C3.6 of AHRI 1250-2020. Specifically, AHRI 1250-2020 requires
that the minimum data collection rate be increased (with respect to
steady-state requirements) from 30 to 60 test readings per hour for
temperature measurements and condensing unit electric power
measurements, and from 3 to 60 test readings per hour for unit cooler
electric power measurements. See Table C3 in Section C3.6.2 of AHRI
1250-2020. DOE anticipates that the increased data collection rate is
necessary since the off-cycle test time interval can be as low as five
minutes whereas the steady-state test will typically run for at least
60 minutes. AHRI 1250-2020 also requires that off-cycle power
measurements be integrated and averaged over the recording interval
with a sampling rate of no less than 1 second unless an integrating
watt/hour meter is used. This requirement is necessary since power is
anticipated to fluctuate during the off-cycle test. Increasing to a 1
second sampling rate allows for an accurate software integration of
power that would be comparable to an integrating watt/hour meter.
c. Off-Cycle Load Points
Currently, the DOE test procedure specifies that off-cycle
evaporator fan power is measured once with no specifications for
ambient conditions. The current test procedure uses this approach
because off-cycle fan power is not expected to vary significantly with
ambient conditions. However, DOE expects the integrated power of
ancillary equipment to potentially vary with ambient conditions,
depending on the refrigeration system design. Consequently, DOE
proposes that the off-cycle power test described in section III.G.1.a
be run at each steady-state ambient test conditions as specified in
Tables 4 through 17 of AHRI 1250-2020. Accordingly, refrigeration
systems with dedicated condensing units located indoors would evaluate
off-cycle power at a single outdoor ambient condition (90 [deg]F dry-
bulb), while systems with dedicated condensing units located outdoors
would determine off-cycle power at three ambient conditions (95 [deg]F,
59 [deg]F, and 35 [deg]F dry-bulb). The measured integrated off-cycle
power results would then be used to calculate a revised AWEF metric, as
described in the following section.
d. Modification to AWEF Calculations
Walk-in cooler AWEF is calculated as a function of steady state
capacity, steady state on-cycle power, and off-cycle unit cooler fan
power in the current test procedure (see Section 7 of AHRI 1250-2009).
10 CFR part 431, subpart R, appendix C, sections 3.3 and 3.4. AWEF for
walk-in freezers considers defrost electrical energy consumption in
addition to steady state gross capacity, steady state on-cycle power,
and off-cycle fan power. Id. As discussed earlier, DOE proposes to
update the AWEF calculation for refrigeration systems to account for
off-cycle power more fully, not just off-cycle evaporator fan power. To
do so, DOE proposes adopting the off-cycle calculations in AHRI 1250-
2020, which replace integrated off-cycle evaporator fan power with the
combined integrated off-cycle power from the unit cooler and condensing
unit in each equation. Additionally, for unit coolers tested alone, DOE
proposes to update the AWEF calculation to account for all unit cooler
off-cycle power--not just the evaporator fan power.\42\ To do so, DOE
proposes adopting the off-cycle calculations in AHRI 1250-2020, which
replace integrated off-cycle fan power with integrated off-cycle power
in the unit cooler equation.
---------------------------------------------------------------------------
\42\ DOE notes that under this proposal, condensing unit off-
cycle power is not explicitly accounted for unit coolers; rather,
the total energy contribution from the condensing unit is based on a
defined EER lookup table, which is currently found in Table 17 of
AHRI 1250-2009 (incorporated by reference, 10 CFR 431.303(b)). This
NOPR proposes changing that to Table 18 of AHRI 1250-2020. This
aspect of the proposed unit cooler test method is consistent with
the current method specified in appendix C to subpart R of 10 CFR
part 431.
---------------------------------------------------------------------------
DOE, however, proposes deviating from the AHRI 1250-2020
calculations for off-cycle energy use for outdoor refrigeration
systems. DOE notes that the AHRI 1250-2020 equations for average
refrigeration system total power input for bin temperature
Tj, e.g., Equation 13, do not appear to use off-cycle power
values for the unit cooler and/or the condensing unit that vary with
Tj. In fact, there are no equations providing the off-cycle
power for either component as a function of Tj in Section 7
of AHRI 1250-2020, such as there are for net capacity and on-cycle
power input (e.g., Equations 14 through 17). Since the off-cycle power
may vary as a function of outdoor temperature as discussed previously,
DOE proposes to
[[Page 23956]]
provide instructions for calculating off-cycle power as a function of
outdoor temperature based on the measurements made at the three outdoor
test condition temperatures.
For condensing unit off-cycle power, DOE proposes to require that
off-cycle power for Tj less than or equal to 35 [deg]F would
be equal to the power measured for the test condition C off-cycle power
test. For Tj higher than 95 [deg]F, DOE proposes that off-
cycle power would be equal to the power measured for the test condition
A off-cycle power test. Between these two temperatures, DOE proposes
that condensing unit off-cycle power would be determined based on the
test condition B and C measurements when Tj is below 59
[deg]F, and based on the A and B measurements when it is above 59
[deg]F, similar to equations 14 through 17 for on-cycle capacity and
power.
For unit cooler off-cycle power, it is unclear whether to apply a
specific trend correlated to condensing unit outdoor air temperature.
DOE notes that AHRI 1250-2020 did not establish tests for unit coolers
tested alone for different condensing unit outdoor air temperatures,
which supports the suggestion that there is no such trend. Hence, DOE
is not proposing any equations for unit cooler off-cycle power that are
based on the different bin temperatures, Tj. Instead, DOE
proposes that the three-unit cooler off-cycle power measurements that
would be made when testing a matched pair or single-packaged dedicated
system would be averaged, and that the resulting average, with no
dependence on Tj, would be used in the AWEF calculations.
Issue 19: DOE requests comments on its proposals to align the test
procedures for appendix C1 with AHRI 1250-2020, except for the use of
off-cycle power measurements in the AWEF calculations for dedicated
condensing units, matched pairs, or single-packaged dedicated systems
intended for outdoor installation. DOE requests comments on its
proposals for use in the AWEF calculations of the three sets of unit
cooler and condensing unit off-cycle measurements made for outdoor
refrigeration systems.
2. Single-Packaged Dedicated Systems
a. AHRI 1250-2020 Methods for Testing
As discussed in section III.B.3.c, AHRI 1250-2020 expanded methods
of test for single-packaged units to include air enthalpy, calorimetry,
and compressor calibration. Specifically, AHRI 1250-2020 incorporates
the following tests procedures by reference:
(1) Air enthalpy method: ASHRAE 37 and ANSI/ASHRAE 41.6-2014
(``ASHRAE 41.6''), ``Standard Method for Humidity Measurement'';
(2) calorimeter methods: ASHRAE 16, ``Method of Testing for Rating
Room Air Conditioners, Packaged Terminal Air Conditioners, and Packaged
Terminal Heat Pumps for Cooling and Heating Capacity'';
(3) compressor calibration methods: ASHRAE 37 and ANSI/ASHRAE 23.1-
2010.
AHRI 1250-2020 requires two simultaneous measurements of system
capacity (i.e., a primary and a secondary method) for single-packaged
dedicated systems, and Section C9.2.1 of AHRI 1250-2020 requires that
the measurements agree within 6 percent. Table C4 in AHRI 1250-2020
specifies which of the test methods (calorimeter, air enthalpy, and
compressor calibration) qualify as primary and/or secondary methods.
However, as summarized in Table III.9, DOE is proposing to modify the
method of test and test hierarchy table in AHRI 1250-2020 to include a
single-packaged refrigerant enthalpy method--the addition of the
Single-Packaged Refrigerant Enthalpy method is the only change to the
hierarchy of test methods that DOE is proposing. The reasoning behind
this addition is discussed in section III.G.2.d of this document.
Table III.9--Single-Packaged System Test Methods and Test Hierarchy
----------------------------------------------------------------------------------------------------------------
Method of test Allowable use
----------------------------------------------------------------------------------------------------------------
Balanced Ambient Indoor Calorimeter...................... Primary.
Balanced Ambient Outdoor Calorimeter..................... Primary or Secondary.
Indoor Air Enthalpy...................................... Primary or Secondary.
Indoor Room Calorimeter.................................. Primary or Secondary.
Single-packaged Refrigerant Enthalpy \43\................ Secondary.
Outdoor Room Calorimeter................................. Secondary.
Outdoor Air Enthalpy..................................... Secondary.
Compressor Calibration................................... Secondary.
----------------------------------------------------------------------------------------------------------------
b. Waivers
---------------------------------------------------------------------------
\43\ As described in section III.G.2.f, this does not apply to
CO2 single-packaged units.
---------------------------------------------------------------------------
DOE granted a waiver to Store It Cold for single-packaged units on
August 9, 2019. 84 FR 39286. Store It Cold petitioned for a waiver
after determining that the refrigerant enthalpy method specified in
AHRI 1250-2009 was not providing consistent capacity measurements for
its single-packaged dedicated systems. 84 FR 39286, 39287. The
alternate test procedure associated with this waiver requires that the
specified single-packaged basic models shall be tested using the Indoor
Air Enthalpy Method and the Outdoor Air Enthalpy Method in accordance
with ASHRAE 37. 84 FR 39286, 39292. DOE also granted waivers to Air
Innovations, CellarPro, Vinotemp, and Vinotheque for walk-in
refrigeration systems used in wine cellar applications, where some of
the basic models included in these waivers were single-packaged
dedicated systems.\44\ Similar to the Store It Cold waiver, the
alternate test methods included in these other waivers require the
specified basic models to be tested in accordance with the air enthalpy
methods specified in ASHRAE 37 for testing single-packaged dedicated
systems, which is now referenced by AHRI 1250-2020. Use of air enthalpy
methods for testing a single-packaged dedicated system captures the
impact of thermal loss and the infiltration of warm air into the
evaporator portion of these systems. As discussed, DOE proposes to
reference in appendix C1 the methods of test for single-packaged
dedicated systems in Section C9 of AHRI 1250-2020, with some
modifications. Since DOE is proposing that appendix C1 would be
required on the compliance date of any amended energy conservation
standards, were such standards to be adopted, the current test
procedure waivers for specified single-packaged basic models would
expire on the compliance date of proposed appendix C1 if it should be
adopted.
---------------------------------------------------------------------------
\44\ Table III.2 lists the manufacturers that have received a
test procedure waiver or interim waiver for walk-in refrigeration
systems designed for wine cellar applications.
---------------------------------------------------------------------------
[[Page 23957]]
c. Suitability of the Single-Packaged Test Methods in AHRI 1250-2020
In the June 2021 RFI, DOE requested data or comment on the
additional thermal losses associated with single-packaged dedicated
systems, and whether AHRI 1250-2020 fully accounts for these losses. 86
FR 32332, 32344. Lennox, AHRI, and Hussmann stated that the AHRI 1250-
2020 single-packaged formulas account for additional thermal losses.
(Lennox, No. 9 at p. 5; AHRI, No. 11 at p. 10; Hussmann, No. 18 at p.
12) These stakeholders also asserted that the calorimeter test method
should measure any minimal leakage. Id.
In response to the June 2021 RFI, the CA IOUs commented that the
room calorimeter and air enthalpy test methods in AHRI 1250-2020 would
address single-packaged dedicated system test challenges that led to
the Store It Cold waiver petition and subsequent granting of the
waiver. (CA IOUs, No. 14 at p. 2) However, the comment did not
specifically address the single-packaged heat loss or its magnitude.
DOE requested comment on the representativeness of the single-
packaged dedicated test and calculation methods in AHRI 1250-2020 in
the June 2021 RFI. DOE additionally invited comment on whether DOE
should update its test procedure to incorporate AHRI 1250-2020 by
reference. 86 FR 32332, 32343-32344. While Lennox, AHRI, and Hussmann
each supported the AHRI 1250-2020 test methods for single-packaged
dedicated systems, these stakeholders stated that these test procedures
have not yet been fully evaluated and recommended against DOE updating
its test procedure to incorporate single-packaged system-specific
sections of AHRI 1250-2020. (Lennox, No. 9 at p. 5; AHRI, No. 11 at p.
9; Hussmann, No. 18 at p. 12)
The calorimeter tests mentioned previously were originally
developed in ASHRAE 16 for testing room air conditioning units. In the
June 2021 RFI, DOE noted that precise determination of the calorimeter
chamber cooling fluid heat capacity is necessary for an accurate test.
86 FR 32332, 32344. Since air conditioning units do not cool below 32
[deg]F, the freezing temperature of pure water, ASHRAE 16 would not
have encountered problems with this issue, as water can be used as the
calorimetry fluid and the heat capacity of pure water is known. When
testing walk-in refrigeration systems using this method, the fluid may
have to be at a temperature lower than 32 [deg]F, which means that pure
water would not be used. Precise determination of the heat capacity of
glycol-water mixtures may present a challenge, since the concentration
of the mixture must be determined. Therefore, in the June 2021 RFI, DOE
requested feedback on what heat transfer liquids might be used to
maintain test chamber temperature when testing single-packaged
dedicated systems using the calorimeter method included in AHRI 1250-
2020. DOE additionally requested comment on whether the calorimetric
procedure in AHRI 1250-2020 for testing single-packaged dedicated
systems could be modified to enhance test accuracy or repeatability. 86
FR 32332, 32344. Lennox, AHRI, and Hussmann stated that additional
testing is necessary to fully evaluate each test method outlined for
single-packaged units in AHRI 1250-2020. (Lennox, No. 9 at p. 5; AHRI,
No. 11 at p. 10; Hussmann, No. 18 at p. 12) Daikin commented that
standard EN 17432 uses a room calorimetry test for single-packaged
units, with test conditions and a setup figure provided in the comment.
(Daikin, No. 17 at p. 3) DOE notes the calorimetry room method
suggested by Daikin does not appear to have a glycol loop and therefore
does not provide a solution for heat transfer liquids that could be
used when testing single-packaged dedicated systems using the
calorimeter method included in AHRI 1250-2020. After consideration, DOE
has tentatively determined that the comments provided do not
conclusively indicate one way or the other that the AHSRAE 16 test
method is unsuitable for walk-in refrigeration systems. Therefore, DOE
is proposing to adopt the ASHRAE 16 calorimetry methods of test for
single-packaged dedicated systems as referenced in AHRI 1250-2020. This
approach would provide flexibility in selecting from one of the
discussed testing methods even if these methods may be more challenging
to implement for walk-in refrigeration systems than for room air
conditioners. As the comments have not provided sufficient quantitative
information, DOE will continue to consider this question and may take
action at a later date.
DOE also discussed the requirement for a pressure equalizer device
for calorimetry chambers in ASHRAE 16 in the June 2021 RFI. DOE noted
that since the calibrated box method (established in the current DOE
test procedure) does not require such a device, this may increase
testing burden. 86 FR 32332, 32344. DOE discussed two potential
alternatives to this requirement; specifically, (1) no requirement to
address transfer air or pressure equalization, or (2) require leak-free
test facility chambers with no equalization requirement. Id. DOE
requested comment on the requirement for a pressure equalizing device
in ASHRAE 16 and solicited feedback on the expected cost and resource
burdens associated with employing such a device. Id. Lennox, AHRI, and
Hussmann stated that an equalizer device would not be necessary if the
chamber were leak-free, that the addition of an equalizer device has
not been fully evaluated and is expected to increase test burden.
(Lennox, No. 9 at p. 5; AHRI, No. 11 at p. 10; Hussmann, No. 18 at p.
13) Based on the single-packaged system testing conducted by DOE, DOE
is not planning to propose an equalizer device for calorimeter room
testing. DOE notes that a pressure equalizer is typically used when
comfort cooling devices have a damper to bring fresh air into the
cooled environment. Single-packaged dedicated systems do not include
this functionality and therefore a pressure equalizing device is not
necessary.
Finally, DOE requested comment on any alternative test methods to
measure single-packaged dedicated system capacity in the June 2021 RFI.
86 FR 32332, 32344. Lennox, AHRI, and Hussmann confirmed that the test
methods included in AHRI 1250-2020 for testing single-packaged
dedicated systems are sufficient. (Lennox, No. 9 at p. 6; AHRI, No. 11
at p. 10; Hussmann, No. 18 at p. 13)
Testing conducted by DOE on single-packaged units using the room
calorimeter and air enthalpy methods as described in AHRI 1250-2020
suggest that these test methods appropriately account for the thermal
losses experienced by this equipment. Therefore, DOE has tentatively
determined that these methods are representative of single-packaged
system energy use. As such, DOE proposes to adopt the single-packaged
system test procedure in AHRI 1250-2020 with the modifications outlined
in sections III.G.2.d and III.G.2.e of this document. DOE notes that
while there may not be extensive experience applying these test methods
to walk-in refrigeration systems, all the proposed test methods have
been evaluated and are used extensively for testing other HVAC
equipment. Additionally, DOE is required, as soon as practicable after
the granting of any waiver, to publish in the Federal Register a notice
of proposed rulemaking to amend its regulations so as to eliminate any
need for the continuation of such a waiver. 10 CFR 431.401(l). Finally,
DOE emphasizes
[[Page 23958]]
that testing according to proposed appendix C1 would not be required
until such time as compliance is required with any amended energy
conservation standards, should such standards be adopted. As such, were
appendix C1 adopted, the existing waivers would remain in effect until
such time as compliance would be required with appendix C1.
d. Single-Packaged Refrigerant Enthalpy Method
As previously discussed, AHRI 1250-2020 includes 4 potential
primary, and 6 potential secondary test methods for testing single-
packaged dedicated systems (see Table III.9). The refrigerant enthalpy
method is not included in this list. Although the dual instrumentation
test (i.e., two separate measurements using the refrigerant enthalpy
method) is routinely used to evaluate the capacity of matched pair,
dedicated condensing, and unit cooler systems, the DX dual
instrumentation method is generally considered to be impractical for
testing single-packaged dedicated systems. This is primarily because it
requires breaking into the liquid refrigerant line within the packaged
unit, routing the line outside of the unit to pass through two mass
flow meters, and then routing the line back into the unit and through
dual pressure and temperature measurements before it rejoins the
original liquid line at the expansion device inlet. This is generally
inappropriate for a single-packaged unit because the internal volume of
the added liquid line and mass flow meters adds substantially to the
required refrigerant charge, and the entire assembly adds substantial
pressure drop.\45\ As discussed in section III.A.2.e, RSG submitted a
request for waiver and interim waiver to use the refrigerant enthalpy
method to test single-packaged dedicated systems with multiple
refrigeration circuits, using only one mass flow meter per circuit and
using added refrigerant liquid line no longer than 5 feet in
length.\46\ DOE is proposing to adopt a single-packaged refrigerant
enthalpy method that is similar to the alternate test procedure
outlined in RSG's waiver request.
---------------------------------------------------------------------------
\45\ These issues were the primary motivation for and are
described in the Store-it-Cold petition for waiver--see the
discussion in section III.G.2.b of this document.
\46\ The RSG petition for waiver and interim waiver can be found
at www.regulations.gov/docket/EERE-2022-BT-WAV-0010.
---------------------------------------------------------------------------
The single-packaged refrigerant enthalpy method would be based
using the refrigerant-side measurements of the DX Calibrated Box method
in section C8 of AHRI 1250-2020 while simultaneously using one of the
``Primary'' methods listed in the table for single-packaged methods of
test as an air-side measurement. These primary test methods all measure
the capacity delivered to the air passing through the evaporator
section of the system, or to the air that is refrigerated by the
system. Before disassembling the refrigeration system to set up the
refrigerant-side mass flow measurement, a preliminary test at Condition
A would be conducted using only the primary air-side measurement. For
this test, surface-mounted temperature sensors would be installed on
the evaporator and condenser coils, tubing entering and leaving the
compressor, and tubing entering the expansion device. This preliminary
test would be compared to the later test at Condition A using both
airside and refrigerant-side measurements. To ensure that the
refrigerant circuit modifications did not materially alter the system
operation, the later test would be performed to confirm that (1) each
on-coil temperature sensor indicates a reading that is within 1.0 [deg]F of its initial-test measurement, (2) the temperatures
of the refrigerant entering and leaving the compressor are within
4 [deg]F, and (3) the refrigerant temperature entering the
expansion device is within 1 [deg]F. To limit the
alteration of the refrigerant circuit, only 5 feet of tubing shall be
added to the liquid refrigerant lines (not including the flow length
associated with the mass flow meter).
The heat balance applied to single-packaged dedicated systems using
this method would involve comparison of the air-side net capacity to a
net capacity determined based on the gross refrigerant-side capacity
measurement that would include adjustment for the evaporator fan heat
in addition to adjustment for the single-packaged dedicated system
thermal loss. The thermal loss would be calculated similarly to the
duct loss calculation of Section 7.3.3.3 of ASHRAE 37-2009, in which
the heat losses associated with the insulated surface areas subject to
heat transfer are summed based on their surface area, thermal
resistance (which is based on known insulating material and insulation
thickness), and the temperatures on either side of the surface.
Issue 20: DOE requests comment on the proposed single-packaged
refrigerant enthalpy test procedure for evaluating the performance of
single-packaged dedicated systems.
e. Multi-Circuit Single-Packaged Dedicated Systems
Multi-circuit single-packaged refrigeration systems provide a
solution for flammable refrigerants, where safety standards limit the
amount of refrigerant in a refrigeration circuit. Some flammable
refrigerants, like propane, are efficient and have a very low global
warming potential (``GWP''),\47\ making them advantageous design
options for future refrigeration systems. Neither the current DOE test
procedure nor AHRI 1250-2020, which DOE is proposing generally to adopt
through reference in its updated test procedure for walk-in
refrigeration systems, provides a method for testing single-packaged
dedicated systems with multiple refrigeration circuits.
---------------------------------------------------------------------------
\47\ Global warming potential is a measure of a substance's
ability to warm the planet relative to CO2.
CO2 has a GWP of 1 while a traditional HFC refrigerant
like R134a has a GWP of 3400, meaning a ton of R134a warms the
planet 3400 times more than a ton of CO2.
---------------------------------------------------------------------------
In its request for waiver and interim waiver, RSG provided an
alternate test method for testing multi-circuit single-packaged
dedicated systems. (EERE-2022-BT-WAV-0010-0001) This test procedure is
based on the single-packaged refrigerant enthalpy method for single-
packaged units described in section III.G.2.d of this document. The
procedure is duplicated for each refrigeration circuit contained in the
unit such that each circuit returns mass flow, enthalpy in, and
enthalpy out values. The resultant mass flow and enthalpy values are
used to calculate the gross refrigeration capacity for each circuit.
Each circuit's gross capacity is then summed to determine the total
capacity of the system.
DOE has tentatively determined that the alternate approach would
generally provide a reasonable method for determining the capacity of
multi-circuit single-packaged dedicated systems. However, this approach
may not adequately capture the heat loss associated with single-
packaged dedicated systems; therefore, an indoor air refrigeration
capacity test would need to be used to confirm the multiple
refrigeration circuit capacity test. In sum, DOE proposes to adopt the
previously described method for determining the capacity of single-
packaged dedicated systems with multiple refrigeration circuits, with
the additional requirement that the primary test would be an indoor air
refrigeration capacity test where the allowable refrigeration capacity
heat balance is 6 percent.
[[Page 23959]]
In summary, DOE is proposing to adopt the test procedures in
section C8 of AHRI 1250-2020 for testing single-packaged dedicated
systems with modifications to allow for secondary refrigerant enthalpy
tests, and to accommodate multi-circuit single-packaged dedicated
systems. The proposed test methods and their designation as primary or
secondary tests are outlined in Table III.9 of this document.
f. CO2 Single-Packaged Dedicated Systems
The current DOE test procedure for single-packaged dedicated
systems uses dual instrumentation refrigerant enthalpy methods. Using
these methods, the current test procedure does not provide
representative values for single-packaged dedicated systems that use
CO2 as a refrigerant because CO2 remains in a
gaseous state in those areas where mass flow meters are placed. The
typical mass flow meters do not deliver accurate readings unless the
medium being measured is in liquid form. However, the single-packaged
dedicated system test methods in AHRI 1250-2020 use air enthalpy
measurements and would not require any refrigerant mass flow
measurements. This means single-packaged refrigeration systems that use
CO2 as a refrigerant can be tested using these methods with
no issues. Therefore, DOE proposes that single-packaged refrigeration
systems that use CO2 as a refrigerant be tested using the
test methods for single-packaged dedicated systems outlined in AHRI
1250-2020.
3. Detachable Single-Packaged Dedicated Systems
As discussed in section III.A.2.g DOE is aware of refrigeration
systems that are installed with the evaporator unit through the wall of
the walk-in, but with the condensing unit installed remotely and
connected to the evaporator with refrigerant lines--DOE has defined
this equipment as ``detachable single-packaged dedicated systems.''
Neither subpart R, appendix C, nor AHRI 1250-2020 contain provisions
for testing these walk-in refrigeration systems. Detachable single-
packaged dedicated systems may be tested as either systems with the
condensing unit and unit cooler in separate housings or as single-
packaged dedicated systems. Testing as the former is more typical of
the walk-in industry and therefore may be less burdensome. However,
testing as a single-packaged system using the indoor air enthalpy test
would account for the heat loss of the evaporator installation. Since
the single-packaged indoor air enthalpy method would be more
representative of these separable single-packaged dedicated systems,
DOE is proposing as part of new appendix C1 and 10 CFR
429.53(a)(2)(i)(C) that detachable single-packaged dedicated systems
would be tested using the test procedure for single-packaged dedicated
systems.
Issue 21: DOE requests comment on testing detachable single-
packaged dedicated systems using the test procedure for single-packaged
dedicated systems.
4. Attached Split Systems
As discussed in section III.A.2.f., DOE is aware of refrigeration
systems that are sold as matched systems and permanently attached to
each other with beams. These systems are mounted to the cooler box with
the beams piercing the interior wall of the walk-in. As discussed in
section III.A.2.f, DOE is proposing to classify these systems as
``attached split systems.'' While thermal losses are expected to be
lower for an attached split system than a single-packaged system since
attached split systems have comparatively more insulation between the
condenser and evaporator sides, DOE has preliminarily confirmed through
testing that these systems still experience some heat leakage when
compared to traditionally-installed systems that have the dedicated
condensing unit and the unit cooler in separate housings. However, this
heat leakage has not been studied extensively and DOE is aware that it
may be difficult to calculate. Because of this issue, DOE is proposing
in new appendix C1 and 10 CFR 429.53(a)(2)(i)(D) that attached split
systems would be tested as a matched pair using refrigerant enthalpy
methods.
Issue 22: DOE requests comment on its proposal that attached split
systems be tested using refrigerant enthalpy methods.
5. Systems for High-Temperature Freezer Applications
As discussed in the December 2016 final rule, stakeholders
commented that high-temperature freezer walk-ins, which have an
enclosed storage (i.e., room) temperature range of 10 [deg]F to 32
[deg]F, are typically refrigerated with medium-temperature dedicated
condensing units. 81 FR 95758, 95790. Under the statutory definitions
of ``walk-in cooler'' and ``walk-in freezer,'' this equipment would be
considered a walk-in freezer because its room temperature is less than
or equal to 32 [deg]F. (42 U.S.C. 6311(20))
Accordingly, these refrigeration systems would be tested using a
room temperature of -10 [deg]F, as specified in subpart R, appendix C.
However, stakeholders commented that it is difficult for these medium-
temperature refrigeration systems to meet this temperature condition
when using lower GWP refrigerants.\48\ 81 FR 95758, 95790. Lennox
offered data suggesting that medium-temperature units generally perform
more efficiently at the 10 [deg]F operating condition (i.e., the low
end of the cited ``high-temperature freezer'' temperature range) than
low-temperature systems. (Docket EERE-2015-BT-STD-0016, Lennox, No. 89
\49\ at pp. 2-5) Lennox suggested that this ``high-temperature
freezer'' application may justifiably represent a third class of walk-
in refrigeration systems, but also noted the reporting and testing
burden that establishing an additional set of classes would incur. Id.
In response, DOE noted that manufacturers of equipment that cannot be
tested in a way that properly represents their performance
characteristics may petition DOE for a test procedure waiver, as
detailed in 10 CFR 431.401. DOE also indicated that it may consider
amending its regulations by establishing new equipment classes and
applicable test methods. 81 FR 95758, 95791.
---------------------------------------------------------------------------
\48\ Lennox commented that the industry was moving to low-GWP
refrigerants in response to the Environmental Protection Agency
final rule under the Significant New Alternatives Policy (``SNAP'')
program that prohibited the use of R-404A in certain retail food
refrigeration applications, including WICF refrigeration systems
starting July 20, 2016. (Docket EERE-2016-BT-TP-0030, Lennox, No. 13
at p. 2) For further discussion of the SNAP rule, see section
III.G.9 of this document.
\49\ Available at www.regulations.gov/document?D=EERE-2015-BT-STD-0016-0089.
---------------------------------------------------------------------------
In the June 2021 RFI, DOE presented three potential approaches for
testing and certifying high-temperature freezers. One approach would
provide for testing and certification based on the standardized 35
[deg]F walk-in cooler temperature (or corresponding refrigerant suction
conditions), if the walk-in refrigeration system is marketed at or
above 10 [deg]F. By extension, the approach would also allow
representations of performance (e.g., capacity, power input) of such
medium-temperature refrigeration systems for walk-in temperatures at 10
[deg]F and higher without requiring them to be tested and certified
based on the -10 [deg]F low-temperature walk-in test condition. 86 FR
32332, 32350.
DOE could establish new definitions for the terms ``high-
temperature freezer system'' and ``medium-temperature refrigeration
system,'' that implement this potential structure. For example, ``high-
temperature freezer system'' could be defined as ``a refrigeration
[[Page 23960]]
system used to cool the interior of walk-in freezers and maintain a
room temperature of between 10 [deg]F and 32 [deg]F,'' while ``medium-
temperature refrigeration system'' could be defined as ``a
refrigeration system used to cool the interior of a walk-in cooler or a
walk-in freezer operating above 32 [deg]F.''
A second alternative presented in the June 2021 RFI would be to
require walk-in cooler refrigeration systems to be tested and certified
at their lowest application temperature conditions. 86 FR 32332, 32350.
This approach would be similar to that taken for commercial
refrigerators, freezers, and refrigerator-freezers, where manufacturers
report the lowest application product temperature, i.e., the lowest
average compartment temperature at which the equipment can operate
during testing (section 2.2 of appendix B to part 431, subpart C). For
walk-ins, this concept could be based on the lowest evaporator return
air temperature for matched pair refrigeration systems and the lowest
saturated suction temperature (and a suitable corresponding return gas
temperature) for dedicated condensing units tested alone. This approach
would result in ratings for units used in high-temperature freezer
applications that are representative of field performance, since the
refrigeration system would be tested at a representative box
temperature for such an application. Further, this approach would not
presuppose what the optimal high-temperature freezer operating
condition would be since it avoids selecting a standardized condition
that may be unachievable by some units. However, AWEF ratings obtained
from the lowest application temperature for different units, which
would be rated for different box temperatures, would not be directly
comparable. This approach would also add testing and reporting burden
associated with the additional test condition.
Finally, DOE presented a third approach in the June 2021 RFI, that
would establish a single standardized test condition at which walk-in
cooler refrigeration equipment would be tested. 86 FR 32332, 32350.
This approach would result in AWEF ratings that are not as reflective
of the expected field performance as compared with the lowest
application temperature approach. Under a standardized test condition
approach, all walk-in cooler refrigeration systems would be rated at
the same condition, providing more directly comparable ratings for
models that serve similar applications.
In the June 2021 RFI, DOE requested comment on the three potential
approaches for addressing high-temperature freezer walk-ins as well as
any other potential approaches that DOE did not discuss. 86 FR 32332,
32350. Lennox, AHRI, Keeprite, National Refrigeration, and Hussmann
supported the first option presented by DOE, specifically, testing and
rating high-temperature freezer systems at 35 [deg]F. (Lennox, No. 9 at
p. 10; AHRI, No. 11 at p. 15; Keeprite, No. 12 at p. 3; National
Refrigeration, No. 17 at p. 2; Hussmann, No. 18 at pp. 17-18) Keeprite
and National Refrigeration both stated that this approach would
eliminate the need to create a new class of equipment, and thus avoid
additional testing. (Keeprite, No. 12 at p. 3; National Refrigeration,
No. 17 at p. 2) Additionally, Keeprite stated that medium-temperature
equipment design is no different from high-temperature freezer
equipment design and therefore concluded that testing the same
equipment twice would have no tangible benefit. (Keeprite, No. 12 at p.
3) ASAP and the CA IOUs recommended the third option presented by DOE,
which suggested establishing new, representative test conditions for
high-temperature freezers irrespective of their lowest operating
temperature. (ASAP, No. 13 at p. 3; CA IOUs, No. 14 at p. 4)
Specifically, the CA IOUs stated that they support establishing
additional equipment classes for refrigeration systems that are not
well represented by the 35 [deg]F indoor test conditions in DOE's
current test procedure. (CA IOUs, No. 14 at pp. 3-4) DOE understands
the CA IOUs comment to infer that for systems not well represented by
the 35 [deg]F indoor test conditions, this equipment should be included
in a separate equipment class and energy use determined at a more
representative temperature, with definitions and labelling that clearly
identify that these units have different test conditions than
`standard' walk-in refrigeration systems.
In the June 2021 RFI, DOE also requested information to inform the
development of test procedures for high-temperature freezer systems. 86
FR 32332, 32350. Specifically, DOE sought comment on the test procedure
parameters or calculations that would need to be modified to test
medium-temperature refrigeration systems in the high-temperature
freezer range. Id. Lennox, AHRI, Keeprite, National Refrigeration, and
Hussmann stated that no new test procedures would be necessary if the
DOE test procedure were to require testing and rating high-temperature
freezers at 35 [deg]F. (Lennox, No. 9 at pp. 10-11; AHRI, No. 11 at pp.
15-16; Keeprite, No. 12 at p. 3; National Refrigeration, No. 17 at p.
2; Hussmann, No. 18 at pp. 18-19)
As also discussed in the June 2021 RFI, if DOE were to pursue the
lowest application temperature approach or the standardized high-
temperature freezer test condition approach, DOE would need to
establish certain new default values to calculate the AWEF and net
capacity of stand-alone high-temperature freezer dedicated condensing
units. 86 FR 32332, 32350. Currently, the test procedure provides
equations for determining evaporator fan power, defrost energy, and
defrost heat load, all of which are used in lieu of matched unit cooler
test data (section 3.4.2 of subpart R, appendix C).
The current test procedure offers two separate equations that
relate the cooling capacity to the evaporator fan power for medium- and
low-temperature unit coolers (section 3.4.2.2 of subpart R, appendix
C). Based on the condensing unit capacity at the medium-temperature
test condition (35 [deg]F box temperature), using the medium-
temperature equation seems to be the most appropriate approach since
the dedicated condensing units in question would also be certified as
medium-temperature dedicated condensing units. This approach also
assumes that fan energy use at high-temperature freezer conditions
would be the same as fan energy use at medium-temperature conditions
since it makes no adjustment in the calculated fan power for the high-
temperature freezer application. DOE requested comment on the
appropriateness of using the current medium-temperature refrigeration
system default fan input power equations (found at section 3.4.2.2 of
subpart R, appendix C) to represent the fan input power of high-
temperature freezer refrigeration systems. 86 FR 32332, 32350. In
response, Lennox, AHRI, and Hussmann recommended using the current low-
temperature default fan input power equation since medium-temperature
dedicated condensing units are typically paired with low-temperature
unit coolers for use in high-temperature freezer applications and low-
temperature unit coolers operate at higher suction temperatures than
medium-temperature unit coolers. (Lennox, No. 9 at p. 11; AHRI, No. 11
at p. 16; Hussmann, No. 18 at p. 19)
In the current test procedure, defrost energy and defrost heat load
for stand-alone dedicated condensing units are estimated based on the
condenser capacity using an equation in section 3.4.2 of subpart R,
appendix C. The calculations apply only to freezer models, since they
assume that
[[Page 23961]]
refrigeration systems serving walk-in coolers are not equipped for
defrost capability and thus have no defrost energy or heat load.
However, medium- temperature refrigeration systems used for high-
temperature freezer applications require defrost capability because
frost that collects on the evaporator during the compressor off-cycle
will not melt in sub-freezing walk-in temperature conditions. The
energy and heat load of these high-temperature freezer defrost systems
may differ significantly from those of -10 [deg]F freezers. Therefore,
proper accounting for defrost of high-temperature freezer refrigeration
systems requires developing a modified calculation. The equation found
in section 3.4.2.4 of subpart R, appendix C, calculates freezer
equipment daily defrost energy use (``DF'') using the condenser
capacity (``qmix,cd'') and the number of defrost cycles per
day (``NDF''). The daily defrost heat load
(``QDF'') is directly dependent on DF (see relevant equation
in section 3.4.2.5 of subpart R, appendix C). DOE anticipates
calculating defrost impacts for high-temperature freezers, if adopted,
would use similar equations with different magnitudes. In the June 2021
RFI, DOE requested information or data to inform the use of potential
modifications to the defrost equations for high-temperature freezers,
and whether frost loads and/or defrost frequency are different for
high-temperature freezers when compared to walk-in freezers that
operate at a temperature of -10 [deg]F. 86 FR 32332, 32350. Lennox,
AHRI, and Hussmann responded that modifications to defrost energy
equations are unnecessary for high-temperature freezer applications
since calculations for a freezer operating at -10 [deg]F, 0 [deg]F, and
10 [deg]F would result in a negligible difference in defrost energy
use. (Lennox, No. 9 at p. 11; AHRI, No. 11 at p. 16; Hussmann, No. 18
at pp. 19-20)
DOE recognizes that testing high-temperature freezer refrigeration
systems at a consistent test condition is important to ensure test
procedure consistency and to provide comparable performance values in
the market. Additionally, DOE acknowledges that testing high-
temperature freezer refrigeration systems at a temperature less than 35
[deg]F would be more representative of their actual energy use;
however, it is not clear if the potential additional test burden
justifies including an additional test condition for walk-in cooler
refrigeration systems. Therefore, DOE has tentatively determined that
medium-temperature dedicated condensing units used in high-temperature
freezer applications would continue to be tested according to subpart
R, appendix C; however, DOE may revisit its approach for this equipment
in a future rulemaking.
6. Systems for High-Temperature Applications
As discussed in the June 2021 RFI, DOE is aware of wine cellar
(high-temperature) refrigeration systems that fall within the walk-in
definition but that may be incapable of being tested in a manner that
would yield representative performance results during a representative
average use cycle under the current version of the walk-in test
procedure. 86 FR 32332, 32344. For example, wine cellar refrigeration
systems that may be installed in some commercial settings are designed
to operate at a temperature range of 45 [deg]F to 65 [deg]F. Under the
current walk-in test procedure, walk-in coolers must be tested while
operating at 35 [deg]F--see Section 3.1.1 of subpart R, appendix C. To
the extent that a wine cellar refrigeration system does not operate at
35 [deg]F, applying the required 35 [deg]F testing temperature
condition when evaluating the energy usage of this equipment would not
produce results representative of an average use cycle.
As discussed in section III.A.2.c, DOE has received requests for
waiver and interim waiver from several manufacturers from the test
procedure in subpart R, appendix C, for basic models of wine cellar
refrigeration systems. DOE engaged with AHRI, the industry trade
association, to discuss how to develop a consistent alternate testing
approach for high-temperature refrigeration systems that would apply to
all impacted manufacturers. Ultimately, AHRI submitted a memorandum on
behalf of its wine cellar members supporting (1) a 45 [deg]F minimum
operating temperature for high-temperature refrigeration systems, and
(2) testing at 50 percent of maximum external static pressure, with
manufacturers providing maximum external static pressure values to
DOE.\50\ DOE has granted interim waivers or waivers to the
manufacturers listed in Table III.2 for specified basic models of wine
cellar refrigeration systems. These waivers provide an alternate test
procedure for specific basic models of single-packaged dedicated
systems, matched pair, and unit-cooler-only high-temperature
refrigeration systems.
---------------------------------------------------------------------------
\50\ Memorandum from AHRI, ``Department of Energy (DOE) Wine
Cellar Cooling Systems Test Procedure Waiver Industry Comments from
AHRI Membership,'' August 18, 2020. (EERE-2019-BT-WAV-0028, No. 5
(CellarPro); EERE-2019-BT-WAV-0029, No. 5 (Air Innovations); EERE-
2019-BT-WAV-0038, No. 5(Vinotheque); EERE-2019-BT-WAV-022, No. 2
(Vinotemp))
---------------------------------------------------------------------------
In the June 2021 RFI, DOE requested comment on the alternative test
procedure for high-temperature refrigeration systems, and if the
procedure would be appropriate for basic models other than those
specified in the waivers. 86 FR 32332, 32345. AHRI and Lennox both
recommended that DOE adopt the test procedures outlined in the waivers.
(Lennox, No. 9 at p. 6; AHRI, No. 11 at p. 11) AHRI and Lennox also
stated that the ASHRAE 210P subcommittee is evaluating the inclusion of
the waiver revisions into their test standard. Id.
DOE is proposing to include a test procedure for testing and rating
high-temperature matched-pair \51\ systems. The proposed test procedure
specifies an air entering dry-bulb temperature of 55 [deg]F. DOE
proposes that testing high-temperature refrigeration systems that are
single-packaged systems be conducted using one of the following: The
indoor air enthalpy method; the outdoor air enthalpy method; the
compressor calibration method; the indoor room calorimeter method; the
outdoor room calorimeter method; or the balanced ambient room
calorimeter method as specified in AHRI 1250-2020.
---------------------------------------------------------------------------
\51\ A ``matched refrigeration system'' is also called a
``matched pair'' and is a refrigeration system where the condensing
system is distributed into commerce with a specific unit cooler(s).
See 10 CFR 431.302.
---------------------------------------------------------------------------
As discussed in the June 2021 RFI, many refrigeration systems for
wine cellars are designed for both ducted and non-ducted air delivery.
86 FR 32332, 32345. The current DOE test procedure does not address the
testing of ducted systems. In section III.A.1.d, DOE proposed including
ducted single-packaged units in the scope of the walk-in test
procedure. In section III.A.2.d, DOE proposed a definition for a ducted
fan coil unit and proposed removing the restriction of ducts from the
definition of a single-packaged unit. The alternate test approach in
the waivers requires that testing of ducted units be conducted at 50
percent of the maximum external static pressure (``ESP''), subject to a
tolerance of -0.00/+0.05 in. wc.\52\ DOE requested feedback on its
approach for testing ducted units, if testing at 50 percent of maximum
ESP is representative, if there are other industry test methods that
include testing of ducted. 86 FR 32332, 32345. Lennox and AHRI
supported testing at 50 percent of the maximum ESP, stating
[[Page 23962]]
that it will provide representative performance values. (Lennox, No. 9
at p. 6; AHRI, No. 11 at p. 11) The CA IOUs recommended that DOE
require manufacturers to publish the maximum ESP to ensure that
consumers do not exceed the maximum static pressure when they install
these units so that the efficiency and operating capacity measured by
the test procedure are representative of average use. (CA IOUs, No. 14
at p. 4)
---------------------------------------------------------------------------
\52\ Inches of water column (``in. wc'') is a unit of pressure
conventionally used for measurement of pressure differentials.
---------------------------------------------------------------------------
Consistent with the waivers that DOE has granted for high-
temperature refrigeration systems, DOE proposes to require that testing
for ducted systems would be conducted with ducts fitted and at 50
percent of the unit's maximum ESP, subject to a tolerance of -0.00/
+0.05 in. wc. DOE would include this provision to apply to any ducted
units, not strictly high-temperature refrigeration systems. DOE
proposes adding clarification on how to set ESP as follows. If testing
using either the indoor or outdoor air enthalpy method, which includes
a measurement of the air volume rate, the airflow measurement apparatus
fan would be adjusted to set the external static pressure--otherwise,
the external static pressure could be set by symmetrically restricting
the outlet of the test duct.
DOE has tentatively determined that requiring manufacturers to
publish the maximum ESP could further ensure that the test conditions
are representative of installation conditions. DOE intends to address
in a future certification rulemaking the certification of the maximum
ESP for each ducted unit. However, DOE proposes at this time to include
a contingency in the test procedure for those cases where the maximum
ESP is not listed in the installation instructions. DOE proposes that
if the ESP is not provided, it would be set such that the air volume
rate for the test is equal to two-thirds of the value that is measured
for zero ESP operation. Making the measurements and adjustments
required for this setup step would require use of an airflow
measurement apparatus.
Issue 23: DOE requests comment on provisions for setting ESP when
testing ducted units.
Finally, in the June 2021 RFI, DOE requested comment on any other
issues regarding the testing of wine cellar (high-temperature)
refrigeration systems. 86 FR 32332, 32346. Lennox and AHRI suggested
that DOE work with wine cellar manufacturers to incorporate high-
temperature refrigeration systems adequately as a separate category.
(Lennox, No. 9 at p. 7; AHRI, No. 11 at p. 12) Lennox and AHRI also
both suggested that there may need to be a high medium temperature
category of ducted indoor and outdoor units. Id. The same commenters
noted the impact of HFC regulations on wine cellar refrigeration and
recommended alternative refrigerants be evaluated. Id. DOE may evaluate
equipment categories and refrigerant requirements for high-temperature
refrigeration systems in a future energy conservation standards
rulemaking. The CA IOUs recommended that definitions and labeling be
developed to clearly differentiate high-temperature refrigeration units
from medium temperature units. (CA IOUs, No. 14 at pp. 3-4) In response
to the comment from the CA IOUs, DOE has proposed a high-temperature
refrigeration system definition that differentiates these units from
other refrigeration systems.
7. Variable-, Two-, and Multiple-Capacity Systems
As discussed in the June 2021 RFI, DOE expected the majority of
refrigeration equipment within the dedicated condensing class to be
certified as dedicated condensing units tested alone, with a much
smaller number of systems certified as matched pairs. 86 FR 32332,
32348-32349. DOE's review of CCMS data has confirmed that most
certified dedicated condensing unit basic models are dedicated
condensing units tested and rated alone rather than matched pairs. This
is consistent with comments made during the 2014 and 2016 rulemakings.
However, the current DOE test procedure does not include a method for
assessing stand-alone multiple- and variable-capacity systems.
Similarly, AHRI 1250-2020 does not include test procedures or
conditions for indoor variable- or two-capacity units. To address this
gap, the ASRAC Working Group recommended that DOE amend its test
procedure to allow for separate ratings of stand-alone variable-
capacity dedicated condensing units. (ASRAC Term Sheet Recommendation
#6)
Historically, refrigeration systems have been designed using a
single-speed compressor, which operates at full cooling capacity while
the compressor is on. To match the cooling load of the refrigerated
space, which in most cases is less than the full cooling capacity of
the compressor, a single-speed compressor cycles on and off. In
contrast, variable-speed systems employ an inverter-driven compressor
that can reduce its speed to match the cooling load. Accordingly, a
variable-speed compressor can deliver cooling that more closely matches
the load. This can reduce energy use by unloading the system's heat
exchangers, allowing them to operate more effectively, and may also
allow reduction of fan speeds, which can further enhance savings
potential. Emerson's digital technology, used in scroll compressors,
can also vary the average refrigerant flow by cycling the engagement of
the scroll elements that make up the compressor--the duty cycle of this
engagement within a cycle time on the order of 15 to 20 seconds can be
varied to adjust average capacity. Similarly, a two- or multiple-
capacity compressor can reduce its displacement (volume intake per
revolution), for example in a multiple-cylinder reciprocating
compressor by ``unloading'' individual cylinders within the compressor.
This allows the compressor to more closely match the required cooling
load. Other staging technologies have been used, including multiple
compressors and scroll compressors with a closable port that
deactivates the outermost scroll wraps when open, thus reducing
effective displacement. DOE is aware of some multiple- or variable-
capacity dedicated condensing units that are currently available on the
market using such compressor technologies.\53\
---------------------------------------------------------------------------
\53\ Multiple-capacity product information from one manufacturer
can be found at www.regulations.gov under Docket EERE-2017-BT-TP-
0010, No. 4.
---------------------------------------------------------------------------
The current DOE test procedure measures the performance of a walk-
in condensing unit while operating under a full cooling load at a fixed
capacity; i.e., the compressor is operated continuously in its ``on''
state. See Tables 11 through 14 of AHRI 1250-2009, and section 3 of
subpart R, appendix C, for further details. While AHRI 1250-2009 and
AHRI 1250-2020 both include test methods for two-, multiple-, and
variable-capacity matched pair refrigeration systems with outdoor
dedicated condensing units, there is no test method for such dedicated
condensing units when tested alone.
In the June 2021 RFI DOE requested information on the development
of test standards for, the efficiency gains of, and the market
availability of multiple and variable-capacity systems. 86 FR 32332,
32349. Lennox, AHRI, Keeprite, National Refrigeration, and Hussmann all
stated that the market for variable capacity units is low and does not
warrant test procedure changes. (Lennox, No. 9 at pp. 9-10; AHRI, No.
11 at p. 14; Keeprite, No. 12 at p. 2; National Refrigeration, No 17 at
p. 2; Hussmann, No. 18 at p. 17) Keeprite stated that variable capacity
units are most often designed in tandem with the evaporator unit, and
that AHRI 1250-
[[Page 23963]]
2020 tests were acceptable for all systems on the market. (Keeprite,
No. 12 at p. 2) ASAP and NEEA recommended DOE develop a test method for
dedicated condensing units tested alone. (ASAP, No. 13 at p. 2; NEEA,
No. 16 at p. 2) NEEA notes that no matched systems are certified in
CCMS indicating that the lack of test procedure may be limiting market
adoption. (NEEA, No. 16 at p. 2) Similarly the CA IOUs stated that
accurately measuring the field performance of variable capacity units
is key for market adoption. (CA IOUs, No. 14 at p. 2) ASAP noted the
ASRAC Working Group's recommendation to develop a test procedure for
dedicated condensing units tested alone. (ASAP, No. 13 at pp. 2-3)
ASAP, the CA IOUs, and NEEA all recommended that DOE evaluate whether
AHRI 1250-2020 has the capability to measure real world cycling
conditions of refrigeration systems. (ASAP, No. 13 at p. 2; CA IOUs,
No. 14 at pp. 2-3; NEEA, No. 16 at p. 2) The CA IOUs note that this is
important for more widespread adoption of variable capacity technology.
(CA IOUs, No. 14 at p. 2) The CA IOUs recommended a potential
alternative of testing variable capacity systems only as matched
systems and having matching guidelines, similar to ASHRAE 29 or AHRI
810. (CA IOUs, No. 14 at p. 3)
DOE acknowledges the small market share of variable- and multiple-
capacity units but notes that the ASRAC Working Group agreed to the
need for such test procedures for dedicated condensing units tested
alone. Because of this, DOE proposes adding test procedures and
conditions for variable-, two-, and multiple-capacity dedicated
condensing units. DOE also proposes test methods for variable-, two-,
and multiple-capacity matched pairs with indoor dedicated condensing
units. To support these proposed additions, DOE also proposes to add a
definition specifying that a ``multiple-capacity'' refrigeration system
is one having three or more stages.
a. Dedicated Condensing Units
As discussed, AHRI 1250-2020 specifies test conditions for matched
variable- and multi-capacity refrigeration systems. Because matched
pairs are complete refrigeration systems, the test conditions do not
address refrigerant conditions in the refrigerant lines connecting the
condensing unit and the unit cooler. Instead, the test specifies
conditions for the air entering the unit cooler and the air entering
the condensing unit. Test procedures for dedicated condensing units
tested alone must address refrigerant conditions in the lines that
would connect the condensing unit to a unit cooler. For example, Table
12 of AHRI 1250-2020 provides test conditions for fixed capacity
refrigerated indoor dedicated condensing units. The table specifies the
refrigerant suction dew point return gas temperature at the condensing
unit suction inlet--these conditions reflect the operation of a
representative unit cooler as well as the temperature rise of
refrigerant as it returns to the condensing unit in the suction line.
In addition, the test procedure calculations also address the direct
energy use of the unit cooler, specifically the unit cooler fan and
(for freezer dedicated condensing units) the defrost heater energy
input and heat impact. Section 7.9 of AHRI 1250-2020 includes equations
providing representative values for some of these parameters--see,
e.g., Equation 130 for on-cycle unit cooler power and Equation 118 for
off-cycle unit cooler power. Section C10.2.2 in AHRI 1250-2020 includes
equations providing representative values for the defrost parameters.
To extend the test procedure to variable- and multiple-capacity
dedicated condensing units, the test would need to specify how the
parameters representing the unit cooler would change at part-load as
compared to full-load. DOE is proposing new test conditions for such
models, including values representing the unit cooler and suction line
influence on operation at part-load. The proposed test conditions
address condensing unit suction inlet refrigerant pressure (represented
as dew point temperature) and temperature for the part-load conditions.
The condenser air inlet conditions would be the same as for existing
tests of dedicated condensing units: Tests only with 90 [deg]F dry bulb
entering air temperature for indoor dedicated condensing units, and
tests at 95 [deg]F, 59 [deg]F, and 35 [deg]F for outdoor dedicated
condensing units. Also, the maximum-capacity test conditions would be
the same as the test conditions for a single-capacity condensing unit
since maximum-capacity operation of a multiple- or variable-capacity
unit should match operation of a single-capacity unit. Specifically,
for cooler dedicated condensing units the maximum-capacity suction
connection dew point temperature would be 23 [deg]F and the refrigerant
temperature would be 41 [deg]F--for freezers, these conditions would be
-22 [deg]F and 5 [deg]F. These parameters would need to be defined for
the part-load test conditions for variable-, multiple-, and two-
capacity dedicated condensing units. In addition, the unit cooler power
levels at part-load would have to be specified, if they would be
different than for full-load. Defrost parameters would not be expected
to be changed for variable-, multiple-, or two-capacity dedicated
condensing units as compared with single-capacity condensing units,
because the defrost would occur when the dedicated condensing unit
compressor is off, and the defrost energy and heat contribution depend
primarily on the representative unit cooler.\54\
---------------------------------------------------------------------------
\54\ Although the compressor would operate during hot gas
defrost, the DOE test procedure calls for testing hot gas defrost
dedicated condensing units using the electric defrost default
parameters. Section 3.5 of appendix C to subpart R of 10 CFR part
431.
---------------------------------------------------------------------------
DOE developed representative values for the part-load refrigerant
conditions at the condensing unit suction inlet based on testing of two
variable-capacity systems. The testing and the development of the
parameters is discussed in greater detail in document EERE-2017-BT-TP-
0010-0021, ``Development of Test Rating Conditions for Two-Capacity,
Multiple-Capacity, and Variable-Capacity Condensing Units.'' The
development is based on the expectation that the unit coolers with
which such dedicated condensing units are paired in the field would
have two-speed fans, either already installed or retrofitted as part of
the condensing unit installation. The test work shows that this
inclusion of two-speed fans would be necessary in order to achieve
efficiency gains with part-load capacity near or lower than half of the
full-load capacity.
(1) Dew Point Target Values for Part-Load Operation: Unit Cooler Exit
As unit cooler-part-load capacity decreases, the suction dew point
rises, approaching the temperature of the air entering the unit cooler
(``air-entering temperature''). However, when a unit cooler fan
switches to reduced speed, the suction dew point falls, in this case
from the reduction in unit cooler evaporator effectiveness when
operating with less airflow. Note that the unit cooler fan power
reduces significantly at reduced speed, and this fan heat reduction can
significantly increase net capacity and efficiency at part-load. DOE
developed representative trendlines for approach of unit cooler exit
evaporating (dew point) temperature to the unit cooler air-entering
temperature for both full- and half-speed fan operation.
However, in its development, DOE limited its approach to air-
entering temperature to account for the expected exit of superheat.
Refrigerant flow
[[Page 23964]]
through unit coolers is controlled by expansion devices controlling for
the presence of a certain refrigerant superheat level at the unit
cooler exit. The test procedure for unit coolers calls for this value
to be set at 6.5 [deg]F in case there is no manufacturer-specified
level. For such operation, the temperature of the refrigerant leaving
the unit cooler is 6.5 [deg]F warmer than the dew point temperature.
However, the refrigerant leaving the unit cooler can be no warmer than
the entering air. Thus, the approach of dew point temperature to
entering air temperature can be no more than 6.5 [deg]F for a unit
cooler operating with this level of superheat. Thus, in its
development, DOE limited the approach to 7 [deg]F to account for this
issue and to provide a 0.5 [deg]F margin.
The selection of dew point temperature at the unit cooler exit for
a given part-load operating condition thus depends on the capacity
level and the unit cooler fan speed (full or half speed). While
different compressor part-load technologies can provide different
levels of capacity turndown, DOE developed representative dew point
levels based on expectations of likely part-load capacity levels.
Specifically, for variable- or multiple-stage dedicated condensing
units, the expected minimum level is roughly \1/3\ of full capacity,
and the expected intermediate level is roughly \2/3\ of full capacity.
For two-capacity dedicated condensing units, DOE used a representative
low-capacity level of roughly half the full-capacity level.
As for unit cooler fan speed, DOE's testing showed that the optimum
capacity level for switching between speeds is near \2/3\--this means
that lower than this capacity level, the higher fan heat and power
input associated with full fan operation outweighs the benefit of
higher evaporator effectiveness. Hence, in determining the appropriate
unit cooler exit condition, DOE assumed that low fan speed would be
used if the compressor or compressors run at an operating level less
than 65 percent. As mentioned, there are different ways that
compressors can achieve part-load conditions. The operating level
determination would be based on the compressor technology.
Specifically, this would involve the speed ratio for a variable-speed
compressor, scroll engagement duty cycle for a digital scroll
compressor, or displacement ratio for a staged compressor system that
changes displacement at part-load. Hence, for those part-load
conditions where the operating level (determined as appropriate for the
compressor technology) is less than or equal to 65 percent, the unit
cooler exit condition would be based on the low fan trend measured in
DOE's test series, and where the operating level is greater than 65
percent, it would be based on the full fan trend. Correspondingly, the
fan power used in calculating AWEF would be based on the operating
level as well.
(2) Compressor Operating Levels During Testing
In order to clarify the compressor operating level, DOE proposes to
define specific terms appropriate for the compressor technologies
expected to be used to achieve part-load operation. These terms would
be ``duty cycle'' for digital scroll compressors, ``speed ratio'' for
variable-speed compressors, and ``displacement ratio'' for compressors
or compressor systems that vary the compressor inlet displacement
volume to achieve capacity modulation.
DOE proposes the following definitions:
Displacement Ratio, applicable for a staged positive
displacement compressor system, means the swept volume rate, e.g., in
cubic centimeters per second, of a given stage, divided by the swept
volume rate at full capacity.
Duty Cycle, applicable for a digital compressor, means the
fraction of time that the compressor is engaged and actively
compressing refrigerant.
Speed Ratio, applicable for a variable-speed compressor,
means the ratio of operating speed to the maximum speed.
DOE is proposing to specify use of compressor operating levels
during part-load testing that are consistent with the development of
the representative unit cooler exit dew point targets. For two-capacity
compressors, this is straightforward since there is only one part-load
operating level. For variable-capacity and multiple-capacity
compressors, DOE proposes that the part-load operating levels be the
lowest level (e.g., speed, duty cycle, or stage) available for the
compressor, and that the intermediate level be the nearest available
level to the mean of the full-capacity and minimum-capacity levels. To
clarify this proposal, DOE is proposing to define ``Minimum Speed'' and
``Maximum Speed'' as set out in the regulatory text at the end of this
document, proposed appendix C1 to subpart R of part 431.
(3) Dew Point Target Values for Part-Load Operation: Condensing Unit
Inlet
The previous section discussed the approach for development of
appropriate unit representative cooler exit conditions for part-load
operation of a condensing unit tested alone. However, performance
depends on conditions at the condensing unit inlet. For full-load
operation, the test procedure operating conditions are based on
assuming that the pressure drop in the suction line is equivalent to a
2 [deg]F reduction in dew point temperature. 81 FR 95758, 95792
(December 28, 2016). For part-load operation, the suction line pressure
drop would be lower, due to the reduced refrigerant flow rate. In its
development of condensing unit test conditions, DOE assumed that the
suction line pressure drop would be equivalent to a dew point reduction
of 1 [deg]F when the part-load capacity is 50 percent of the full-load
capacity or more and would be 0.5 [deg]F when the capacity is lower
(see discussion in EERE-2017-BT-TP-0010-0021, ``Development of Test
Rating Conditions for Two-Capacity, Multiple-Capacity, and Variable-
Capacity Condensing Units''). The suction dew point levels at the
condensing unit inlet would then be as indicated in Table III.10 and
Table III.11.
Table III.10--Two-Capacity Dedicated Condensing Unit Suction Dew Points
----------------------------------------------------------------------------------------------------------------
Low capacity, Low capacity,
high unit low unit
High-capacity cooler fan cooler fan
Application suction dew speed, suction speed, suction
point, [deg]F dew point, dew point,
[deg]F [deg]F
----------------------------------------------------------------------------------------------------------------
Cooler.......................................................... 23 25.5 23
Freezer......................................................... -22 -19.5 -22
----------------------------------------------------------------------------------------------------------------
[[Page 23965]]
Table III.11--Variable-Capacity or Multiple-Capacity Dedicated Condensing Unit Suction Dew Points
----------------------------------------------------------------------------------------------------------------
Intermediate Intermediate
Maximum- capacity, high capacity, low Minimum-
capacity unit cooler unit cooler capacity
Application suction dew fan speed, fan speed, suction dew
point, [deg]F suction dew suction dew point, [deg]F
point, [deg]F point, [deg]F
----------------------------------------------------------------------------------------------------------------
Cooler.......................................... 23 25.5 22 26
Freezer......................................... -22 -19.5 -23 -19
----------------------------------------------------------------------------------------------------------------
(4) Target Refrigerant Temperature at Condensing Unit Inlet
As discussed previously, the refrigerant temperature at the exit of
the representative unit cooler is equal to the unit cooler exit dew
point temperature plus the superheat, assumed to be 6.5 [deg]F. The
refrigerant warms up in the suction line as it returns to the
condensing unit. For full-load operation, the test procedure specifies
condensing unit inlet temperature conditions, i.e., 41 [deg]F for
cooler dedicated condensing units and 5 [deg]F for freezer condensing
units. In a cooler system operating at full-load in a 95 [deg]F outdoor
condition, this means that the refrigerant is warmed from 31.5 [deg]F
at the unit cooler exit to 41 [deg]F at the condensing unit inlet. Most
of this warmup would be expected to occur where the suction line is
exposed to 95 [deg]F outdoor conditions, since the cooler interior
temperature at 35 [deg]F is only a few degrees warmer than the
refrigerant exiting the unit cooler. The suction line exposed to
outdoor air conditions can be seen as a heat exchanger with low
effectiveness. For the purposes of determining the trend of suction
line refrigerant temperature increase at part-load, DOE assumed that
the suction line thermal resistance would remain the same as the
capacity level changes. This means that when refrigerant flow is lower
at part-load, the heat transfer effectiveness would be higher, and the
refrigerant temperature rise would be greater. (See the more detailed
discussion in EERE-2017-BT-TP-0010-0021, ``Development of Test Rating
Conditions for Two-Capacity, Multiple-Capacity, and Variable-Capacity
Condensing Units'') The document discusses in more detail how the
suction line temperature rise was calculated for different operating
conditions and related to the operating capacity level of the
condensing unit. Note that for refrigerated outdoor dedicated
condensing units using test condition C, no change in the condensing
unit inlet temperature is assumed for different capacity levels,
because the 41 [deg]F specified for single-capacity systems already
suggests a suction line heat transfer effectiveness greater than 100
percent. Hence, DOE proposes no change in condensing unit inlet
temperature for cooler dedicated condensing units for condition C.
Table III.12--Two-Capacity Dedicated Condensing Unit Return Gas Conditions
----------------------------------------------------------------------------------------------------------------
Unit cooler fan level
Test title corresponding to compressor Freezer return Cooler return
operating level gas, [deg]F gas, [deg]F
----------------------------------------------------------------------------------------------------------------
Capacity, Condition A, Low Capacity........... Low............................. 13.5 45.0
High............................ 12.0 42.5
Capacity, Condition A, High Capacity.......... High............................ 5 41
Capacity, Condition B, Low Capacity........... Low............................. 13.0 41.0
High............................ 11.5 41.5
Capacity, Condition B, High Capacity.......... High............................ 5 41
Capacity, Condition C, Low Capacity........... Low............................. 12.0 42.5
High............................ 10.5 41.0
Capacity, Condition C, High Capacity.......... High............................ 5 41
----------------------------------------------------------------------------------------------------------------
Table III.13--Variable-Capacity Dedicated Condensing Unit Return Gas Conditions
----------------------------------------------------------------------------------------------------------------
Unit cooler fan level
Test title corresponding to compressor Freezer return Cooler return
operating level gas, [deg]F gas, [deg]F
----------------------------------------------------------------------------------------------------------------
Capacity, Condition A, Minimum Capacity....... Low............................. 26.5 53.0
Capacity, Condition A, Intermediate Capacity.. Low............................. 10.5 43.0
High............................ 12.0 45.5
Capacity, Condition A, Maximum Capacity....... High............................ 5 41
Capacity, Condition B, Minimum Capacity....... Low............................. 24.0 46.0
Capacity, Condition B, Intermediate Capacity.. Low............................. 10.0 40.0
High............................ 11.5 41.5
Capacity, Condition B, Maximum Capacity....... High............................ 5 41
Capacity, Condition C, Minimum Capacity....... Low............................. 20.0 41.0
Capacity, Condition C, Intermediate Capacity.. Low............................. 10.0 41.0
High............................ 10.5 41.0
Capacity, Condition C, Maximum Capacity....... High............................ 5 41
----------------------------------------------------------------------------------------------------------------
[[Page 23966]]
(5) Unit Cooler Power To Use for AWEF Calculations
As discussed previously, the proposed test for dedicated condensing
units with more than one compressor capacity is based on the
expectation that a representative unit cooler with which the condensing
unit would be paired in the field will have or be fitted with during
installation a two-speed or variable-speed fan, and that the fan would
operate at half-speed as appropriate for part-load operation. Also
discussed previously, the unit cooler dew point target for the test
depends on the assumption for unit cooler fan operating condition, and
DOE is proposing that half-speed would be used for compressor operating
levels up to 65 percent. AHRI 1250-2020 already provides power input
levels for a representative unit cooler with fans operating at full-
and half-speed levels (for example, see Equations 118 and 130 of the
test standard, providing representative wattages for off-cycle and on-
cycle wattages). DOE proposes that the half-speed off-cycle wattage
would also be used for half-speed on-cycle operation when calculating
AWEF.
(6) Other Aspects of AWEF Calculations
DOE proposes that the calculations used to determine AWEF for
dedicated condensing units with more than one capacity level would be
essentially identical to the calculations for matched pair or single-
packaged dedicated systems once capacity and power input are determined
for each standard operating condition at the different capacity levels.
However, this proposal would adjust the calculation methods for
variable- and multiple-capacity systems, consistent with the direction
taken for calculating efficiency metrics for variable-capacity central
air conditioners and heat pumps in the test procedure final rule
published in 2016 for those products. These changes are described in
section III.G.7.c of this document.
Issue 24: DOE requests comments on its proposals for testing
multiple-, variable-, and two-capacity dedicated condensing units
tested alone. DOE specifically requests comments on (a) the expectation
that a unit cooler with which such a condensing unit is paired in the
field would have two-speed (or variable-speed) fans or be fitted with
such fans during installation, (b) the proposed compressor operating
levels to use for testing, (c) the proposed compressor operating level
at which the unit cooler fan would be assumed to switch to half-speed,
(d) the proposed targets for unit cooler exit and condensing unit inlet
refrigerant temperatures and dew point target temperatures, and (e) the
unit cooler half-fan-speed input wattage.
(7) Information Required for Testing
Testing of dedicated condensing units with multiple capacity levels
requires setting operating conditions for testing that are not required
when testing single-capacity dedicated condensing units. DOE expects
that some of this information may not be readily available in
installation instructions and may consider whether certification of
some of the required information may be needed in a separate rulemaking
addressing certification.
(8) Potential Use of Equations Rather Than Tabulated Values for Target
Test Conditions
The proposed tabulated target values for suction dew point and
suction temperature for part-load operation of dedicated condensing
units shown in Table III.10 through Table III.13 were using
correlations for the trends of unit cooler operation and suction line
pressure drop and heat transfer developed based on test data (See the
discussion in EERE-2017-BT-TP-0010-0021, ``Development of Test Rating
Conditions for Two-Capacity, Multiple-Capacity, and Variable-Capacity
Condensing Units'') The target values also consider likely compressor
minimum operating levels and decisions regarding the unit cooler fan
operating level corresponding to each compressor operating level.
Rather than use a tabular approach to specifying target operating
conditions, DOE could consider direct use of the correlations for
determination of target test conditions. The approach would involve,
for each part-load test, using (1) two correlations to calculate the
target condensing unit suction inlet dew point, and (2) two equations
to calculate target condensing unit suction inlet temperature. This
approach would provide more flexibility in manufacturer decisions
regarding the unit cooler fan level corresponding to any given
compressor staging level and slightly better alignment of the test
conditions to the compressor operating levels. However, it would
require manufacturers to provide more information regarding selection
of test conditions to clarify how models were tested and could be
considered more burdensome by requiring calculation of test conditions.
Depending on comments provided on this topic, DOE may consider adopting
this approach of using the correlations for unit cooler and suction
line trends instead of the tabulated values for setting target test
conditions.
Issue 25: DOE requests comment on whether DOE should set the target
test conditions using correlations for unit cooler and suction line
response to part-load operation rather than the proposed tabular
approach.
b. Indoor Matched Pair and Single-Packaged Units
As discussed previously, AHRI 1250-2020 does not include test
procedures or conditions for indoor variable or multiple-capacity
units. As with dedicated condensing units, DOE proposes to adopt test
methods for indoor matched pair and single-packaged dedicated systems.
Testing of these systems and calculating AWEF for them would require
parallel testing and AWEF calculations for outdoor matched systems,
except that there is only one test condition and the AWEF calculation
would be based only on that one condition. The details for required
test conditions and calculations are presented in section 4.5.6 and
Table 17 and Table 18 of this document showing the proposed regulatory
text revisions.
Issue 26: DOE requests comment on its proposal to include in its
test procedures instructions for testing and determining
representations for indoor matched pair and single-packaged dedicated
systems.
c. Revision to EER Calculation for Outdoor Variable-Capacity and
Multiple-Capacity Refrigeration Systems
AHRI 1250-2020 includes test conditions and calculations to
determine representations, specifically AWEF, for refrigeration systems
having variable-capacity capability. The calculations use a quadratic
equation for determining system EER for intermediate-capacity operation
(see, e.g., Equations 76 through 84 of AHRI 1250-2020). DOE moved from
the same quadratic approach for central air conditioners and heat pumps
(``CAC/HP'') to a linear interpolation method due to concerns about
potential inaccuracies of this method. 82 FR 1426, 1440-1441 (January
5, 2017). DOE proposes to make the same change when testing WICF
refrigeration systems.
Issue 27: DOE requests comment on its proposal to modify the
approach for calculating intermediate-capacity EER for variable-speed
refrigeration systems.
d. Digital Compressors
Dedicated condensing units with digital compressors have been
commercialized (see, e.g., EERE-2017-BT-TP-0010-0020). Digital
compressor operation is discussed in the
[[Page 23967]]
introduction to section III.G.7 of this document. To clarify the
proposed test procedure for digital compressors, DOE proposes to define
the term ``digital compressor'' as a compressor that uses mechanical
means for disengaging active compression on a cyclic basis to provide a
reduced average refrigerant flow rate in response to an input signal.
DOE testing has shown that operating tolerances specified in AHRI
1250-2020 for certain parameters such as refrigerant pressure and mass
flow can be exceeded when a digital compressor operates at part-load.
Nevertheless, DOE testing has shown that the refrigerant enthalpy
method for measuring capacity may still be quite accurate, as long as
the liquid subcooling at the mass flow meter is sufficiently low, as
required in Section C3.4.5 of AHRI 1250-2020. When conducting these
tests, DOE used an integrating mass flow meter and measurement of
temperature and pressure at a frequency of one measurement per second.
DOE calculated capacity using refrigerant enthalpies determined based
on test-period-average values of refrigerant temperature and pressure.
When meeting the mass flow meter subcooling requirements, capacity
balance with a separate calorimetric capacity measurement ranged from
0.2 to 4.1 percent.
Thus, DOE proposes that testing of refrigeration equipment with
digital compressors operating at part-load may use the refrigerant
enthalpy method as a secondary test method, with the following
provisions and adjustments: (1) Pressure and temperature measurement
would be at a frequency of once per second or faster, (2) the operating
tolerances for pressure and temperature at both the inlet and outlet
connections, and for mass flow would not apply, and (3) enthalpies
determined for the capacity calculation would be based on test-period-
average pressure and temperature values.
DOE proposes that the selection of the primary test method for
measuring capacity would depend on the refrigeration system
configuration. For single-packaged dedicated systems, the test methods
proposed to be used as primary methods for any single-packaged
dedicated system would be used (see discussion in section III.G.2of
this document). For matched pairs, the same test methods allowed as
primary methods for single-packaged dedicated systems would be used.
For dedicated condensing units, the primary methods that would be used
would include outdoor air enthalpy method, balanced ambient outdoor
calorimeter, and outdoor room calorimeter measurements.
Issue 28: DOE requests comments on its proposals to address part-
load testing for refrigeration systems with digital compressors.
8. Defrost
The April 2011 final rule referenced AHRI 1250-2009 as DOE's WICF
refrigeration system test procedure, including that standard's
requirement that both frosted and dry coil defrost tests be conducted.
81 FR 21580, 21597. DOE later noted in a supplemental notice of
proposed rulemaking published on February 20, 2014 (``February 2014
SNOPR'') that these tests may be overly burdensome for manufacturers to
conduct due to the difficulty of maintaining the moist air infiltration
conditions for the frosted coil test in a repeatable manner. 79 FR
9818, 9831. Accordingly, in the May 2014 final rule, DOE adopted a set
of nominal values for calculating defrost energy use for a frosted
coil, number of defrosts per day if the unit has an adaptive defrost
system, and daily contribution of heat load. 79 FR 27388, 27401. To
address testing low-temperature dedicated condensing units alone, the
May 2014 final rule established nominal values for the defrost energy
use and thermal load. In addressing refrigeration systems with hot gas
defrost, the May 2014 final rule established nominal values for
calculating hot gas defrost energy use and heat load.\55\ Id.
---------------------------------------------------------------------------
\55\ In a ``hot gas'' defrost system, high-temperature, high-
pressure hot refrigerant gas from the discharge side of the
compressor is introduced into the evaporator, where it condenses,
thereby releasing latent heat into the evaporator. This heat is used
to melt the frost that has accumulated on the outside of the
evaporator coil.
---------------------------------------------------------------------------
The December 2016 final rule removed the method for calculating the
defrost energy and defrost heat load of systems with hot gas defrost
and established a new method to evaluate hot gas defrost refrigeration
systems. That new method treated hot gas defrost refrigeration systems
as if they used electric defrost rather than hot gas defrost. This
method relied on the same nominal values for defrost energy use and
thermal load that the test procedure prescribes for electric-defrost
dedicated condensing units that are tested alone. 81 FR 95758, 95774-
95777. This approach was modified in the March 2021 final rule, which
amended the DOE test procedure by rating hot gas defrost unit coolers
using modified default values for energy use and heat load
contributions that would make their ratings more consistent with those
of electric defrost unit coolers. 86 FR 16027. The scope of the March
2021 final rule is limited to unit coolers only. 86 FR 16027, 16030.
In the June 2021 test procedure (``TP'') RFI, DOE stated that it
was considering whether to include a test method for determining the
energy use associated with defrost and/or a test method to assess and
confirm defrost adequacy. 86 FR 32332, 32347. DOE observed that any
test method for determining defrost energy use and adequacy would have
to provide consistent, repeatable methods for (1) delivering a frost
load to the test coil and (2) measuring the thermal load released into
the refrigerated space during the defrost cycle, regardless of the
method of defrost (e.g., electric or hot gas defrost), all while
ensuring that the procedure provides results reflecting energy usage
during a representative average use cycle and not be unduly burdensome
to conduct. Id. DOE requested information on methods that might provide
a measurable frost load and frost type to ensure repeatable defrost
testing. Additionally, DOE requested data on typical frost loads and
frost type, or information on the type and amount of testing that would
be necessary to validate a method for evaluating frost loads and frost
types during defrost testing. Id.
In response to DOE's request for comment, Lennox, AHRI, National
Refrigeration, and Hussmann recognized that although the injector
system included in appendix E of AHRI 1250-2020 is an improvement, it
remains a challenge to consistently build frost on an evaporator coil
while minimizing interference with calorimeter systems. (Lennox No. 9
at p. 8; AHRI No. 11 at p. 13; National Refrigeration No. 17 at p. 2;
Hussmann No. 18 at p. 15 Keeprite reiterated the technical difficulties
associated with a moist-air loading approach. (Keeprite No. 12 at p. 2)
Each of these stakeholders urged DOE to wait for the completion of
ASHRAE research project WS 1831, ``Validation of a Test Method for
Applying a Standardized Frost Load on a Test Evaporator in a Test
Chamber with an Operating Conditioning System'' (``WS 1831''), before
modifying its defrost test procedure. (Lennox No. 9 at p. 8; AHRI No.
11 at p. 13; National Refrigeration No. 17 at p. 2; Hussmann No. 18 at
p. 15) ASAP also recognized the challenge associated with developing a
test method to measure defrost energy (ASAP No. 13 at p. 2), while the
CA IOUs agreed that AHRI 1250-2020 appendix E provides a good starting
point for a universal defrost test but urged DOE to work with
stakeholders to develop a test procedure for defrost that
[[Page 23968]]
could be used for all walk-in equipment. (CA IOUs No. 14 at p. 3) More
specifically, the CA IOUs suggested that a test procedure for
determining defrost energy consumption would vary the length and
intensity of moisture injections to better represent field conditions.
Id. Similarly, ASAP stressed that the ASRAC Working Group recommended
incorporating a test method for measurement of defrost energy
consumption and encouraged DOE to develop a future test method that
better captures defrost energy use and performance for all defrost
systems. (ASAP No. 13 at p. 2)
DOE recognizes that it is challenging to consistently build frost
on an evaporator coil to assess a unit's defrost performance. In
Section C11 of AHRI 1250-2009, the moisture to provide a frost load is
introduced through the infiltration of air at a 75.2 [deg]F dry-bulb
temperature and a 64.4 [deg]F wet-bulb temperature into the walk-in
freezer at a constant airflow rate that depends on the refrigeration
capacity of the tested freezer unit (equations C11 and C12 in Section
C11.1.1 of AHRI 1250-2009). A key issue with this approach is the
difficulty in ensuring repeatable frost development on the unit under
test, despite specifying the infiltration air dry-bulb and wet-bulb
temperatures. For example, in addition to frost accumulating on the
evaporator of the unit under test, frost may also accumulate on the
evaporator of other cooling equipment used to condition the room, which
could subsequently affect the rate of frost accumulation on the unit
under test (by affecting the amount of moisture remaining in the air).
In past ASHRAE-supported research, researchers created a frost load
by introducing steam directly into the refrigerated space.\56\ However,
as discussed in 1094-RP, this approach can result in the suspension of
ice crystals in the saturated room air and the formation of snow-like
frost on the test coils. The researchers found that this snow-like
frost degrades refrigeration system performance more, and is more
difficult to defrost, than the ice-like frost that forms in sub-
saturated air conditions. Both 622-RP and 1094-RP observed that a
significant portion of the coil frost was converted to water vapor
rather than melted during the defrost cycle. This finding suggests that
measuring the quantity of frost melt water mass may be a poor indicator
of the frost load, since a significant portion of the frost would not
be captured as melt water.\61\
---------------------------------------------------------------------------
\56\ Sherif, S.A., P.J. Mago, and R.S. Theen. A Study to
Determine Heat Loads Due to Coil Defrosting. 1997. University of
Florida: Gainesville, FL. ASHRAE Project No. 622-RP. Report No.
UFME/SEECLSEE-9701 (``622-RP'') and Sherif, S.A., P.J. Mago, and
R.S. Theen. A Study to Determine Heat Loads Due to Coil Defrosting-
Phase II. 2003. University of Florida: Gainesville, FL. ASHRAE
Project No. 1094-RP. Report No. UFME/SEECLSEE-200201 (``1094-RP'').
---------------------------------------------------------------------------
DOE is aware that ASHRAE initiated project WS 1831 on September 2,
2021. The purpose of this research is to examine different approaches
for applying a standardized, repeatable, full-frost accumulation (i.e.,
accumulation of a frost quantity that would typically accumulate
between defrosts during system operation in moist conditions) on
evaporator coils so that the subsequent defrost test provides a
representative indication of energy use associated with defrosting a
frosted coil. Indirect methods for determining full frost load might
include air side temperature, humidity, or pressure drop, refrigerant-
side evaporation temperature or pressure, compressor or unit cooler fan
power consumption, or the refrigerant-to-air or air-side inlet-to-
outlet temperature difference.
Since the defrost test procedure in AHRI 1250-2009, section C11 has
limitations, AHRI 1250-2020 does not include a frosted-coil test but
does include provisions for a dry-coil defrost test.\57\ Industry is
currently evaluating how to create and validate consistent evaporator
coil frost loads; therefore, DOE proposes to maintain the current
calculation-based approach for estimating defrost energy consumption.
Specifically, DOE proposes to incorporate by reference Section C10 of
AHRI 1250-2020 for unit coolers with either electric or hot gas
defrost.
---------------------------------------------------------------------------
\57\ AHRI 1250-2020 includes an adaptive defrost challenge test
in appendix E (``Appendix E'') and a hot gas defrost challenge test
in appendix F (``Appendix F'') that require a frosted coil. The
tests in both of these appendices are labelled as ``informative,''
and were designed to evaluate adaptive defrost or hot gas defrost
functionality, respectively, rather than to quantify defrost energy
use.
---------------------------------------------------------------------------
In the June 2021 RFI, DOE requested comment on whether these and
other updates to AHRI 1250-2020 would, if incorporated by DOE, result
in additional testing burden. 86 FR 32332, 32336. Lennox, AHRI,
Keeprite, and Hussmann recommended that DOE omit Section C10.2.1.1 of
AHRI 1250-2020 from its test procedure since it does little to make the
test procedure more representative but introduces technical challenges
associated with air conditions during the dry coil defrost test.
(Lennox No. 9 at p. 3; AHRI No. 11 at p. 5; Keeprite No. 12 at p. 1-3;
Hussmann No. 18 at p. 6-7) Section C10.2.1.1 of AHRI 1250-2020
specifies that the general test condition tolerances are not applicable
but does require that the indoor entering dry-blub temperature must be
less than or equal to 4 [deg]F and that air velocity in the vicinity of
the test unit must not exceed 500 feet per minute. At this time, DOE
does not have sufficient data to fully evaluate how these test room
condition requirements during the dry coil defrost test would impact
the representativeness of the test procedure relative to any potential
additional test burden. DOE has tentatively decided not to incorporate
Section C10.2.1.1 of AHRI 1250-but will instead continue to investigate
this issue and may decide to include dry coil defrost operating
tolerances in a later rulemaking. While DOE will continue to evaluate
the dry coil defrost test room conditions, DOE emphasizes that it is
proposing to incorporate the entirety of Section C10 of AHRI 1250-2020,
``Defrost Calculation and Test Methods,'' by reference, except for
Section C10.2.1.1, ``Test Room Conditioning Equipment.''
In the following sections, DOE discusses relevant stakeholder
comments and additional proposals for adaptive defrost and hot gas
defrost.
a. Adaptive Defrost
Adaptive defrost refers to a factory-installed defrost control
system that reduces defrost frequency by initiating defrosts or
adjusting the number of defrosts per day in response to operating
conditions rather than initiating defrost strictly based on compressor
run time or clock time. 10 CFR 431.303. In the December 2016 final
rule, DOE established an approach to address systems with adaptive
defrost. 81 FR 95758, 95777. This approach requires that adaptive
defrost features are deactivated during certification testing; i.e.,
for certification, units are tested as if they do not have adaptive
defrost. See subpart R, appendix C, section 3.3.5. However, DOE's
current approach also allows the energy saving benefits of adaptive
defrost to be displayed in public representations and marketing
material (but not for certification purposes). Id. To represent the
benefits of adaptive defrost, a calculation method is provided that
allows the unit under test to reduce its number of defrosts per day
(``NDF'') to the average of its daily dry coil and frosted
coil defrosts (typically 1 and 4, respectively, for an average of 2.5),
rather than basing NDF on the number of frosted coil
defrosts per day (typically 4). Id. DOE's current approach applies to
all refrigeration system configurations (i.e., matched pairs, unit
coolers tested alone, and dedicated condensing units tested alone).
[[Page 23969]]
In the June 2021 TP RFI, DOE observed that a test method to
evaluate the impact of adaptive defrost must evaluate (1) whether a
system waits too long to defrost (i.e., too much frost builds up on the
coils, which impacts on-cycle performance) and (2) if the system
defrosts more than four times per day, which is typical for a
conventional timed defrost. 86 FR 32332, 32348. DOE requested comment
on how the performance of adaptive defrost systems should be accounted
for in the walk-in test procedure and which refrigeration systems
(i.e., matched pairs, unit coolers tested alone, and dedicated
condensing units tested alone) should be eligible for a potential
adaptive defrost test procedure. Lennox, AHRI, Keeprite, National
Refrigeration, and Hussmann stated that adaptive defrost is most
prevalent in matched pairs and that it would be necessary to match unit
coolers and dedicated condensing units to realize adaptive defrost.
(Lennox, No. 9 at p. 9; AHRI, No. 11 at p. 14; Keeprite, No. 12 at p.
2; National Refrigeration, No. 17 at p. 2; Hussmann, No. 18 at p. 16)
The CA IOUs encouraged DOE to develop a test to measure the performance
benefits of adaptive defrost. (CA IOUs, No. 14 at p. 3) While the CA
IOUs stated that Appendix E of AHRI 1250-2020 provides a good starting
point for a defrost test, they suggested that the addition of moisture
as a static load of 0.5 pounds per hour per 1,000 Btu per hour in
Appendix E does not evaluate the full capability of most adaptive
defrost systems and does not sufficiently differentiate between
adaptive control strategies. (CA IOUs, No. 14 at p. 3)
DOE also requested data showing the performance of adaptive defrost
systems relative to non-controlled defrost systems, data showing the
impact of adaptive defrost to on-cycle operation, and data
demonstrating seasonal or daily frosting patterns for walk-in
applications. 86 FR 32332, 32348. In response, the CA IOUs shared test
results from adaptive defrost control systems installed in the field
which show between 0 and 30 percent energy savings compared to baseline
systems with no adaptive defrost control. (CA IOUs, No. 14 at p. 3)
Accordingly, the CA IOUs encouraged DOE to consider varying the length
and intensity of moisture injections to better represent in-field frost
load and differentiate between control strategies. Id.
DOE recognizes the need to develop a representative and repeatable
test method for evaluating adaptive defrost performance, and notes that
appendix E may be an appropriate starting point. DOE also acknowledges
that industry is invested in developing an adaptive defrost test
procedure and that the ASHRAE WS 1831 research project must be
completed in order to understand how to best form a representative and
uniform layer of frost on the defrost coil. DOE appreciates the
information provided by the CA IOUs and will consider it in its
development and/or evaluation of any newly developed test procedure for
quantifying the energy use of adaptive defrost. After considering the
stakeholder comments received, DOE proposes to maintain the current
regulatory approach that reduces the number of defrosts per day in the
AWEF calculation from 4.0 to 2.5, for adaptive defrost systems. DOE
also proposes to maintain its approach where AWEF calculated using the
adaptive defrost credit (i.e., using 2.5 defrosts per day, rather than
4.0) may be used for representation purposes only, and may not be used
when calculating AWEF for compliance with DOE energy conservation
standards. DOE also proposes to maintain its current approach, in which
the adaptive defrost calculation method is applicable to all
refrigeration system configurations (i.e., matched pairs, unit coolers
tested alone, and dedicated condensing units tested alone). Finally,
DOE notes that use of the adaptive defrost credit for representation
purposes only would continue to apply only to factory-installed defrost
control systems. Overall, the optional adaptive defrost strategy that
DOE is proposing for representation purposes can be summarized as
follows:
The adaptive defrost calculation method (i.e., the
adaptive defrost ``credit'') may be used only for representation
purposes, and may not be used to calculate AWEF for compliance
purposes.
All refrigeration system configurations (i.e., matched
pairs, unit coolers tested alone, and dedicated condensing units tested
alone) may use the adaptive defrost calculation method for
representation purposes.
Refrigeration systems may use the adaptive defrost
calculation method for representation purposes only if the adaptive
defrost controller is distributed in commerce with the refrigeration
system.
b. Hot Gas Defrost
As discussed previously, the March 2021 final rule amended the test
procedure to rate hot gas defrost unit coolers using modified default
values for energy use and heat load contributions that would make their
ratings more consistent with those of electric defrost unit coolers but
is limited to unit coolers only. 86 FR 16027, 16030.
In the June 2021 TP RFI, DOE discussed that it was interested in
obtaining feedback on the most practicable method for measuring hot gas
defrost performance. 86 FR 32332, 32347. DOE recognized that in order
to assess the energy performance of a defrost cycle, the test procedure
must measure both the energy consumed and the heat released into the
refrigerated space by the defrost system. Id. DOE further discussed
that for hot gas defrost systems, unlike electric resistance heating
systems, the energy consumed and the heat released are not equivalent,
which makes the current electric defrost test procedure outlined in
AHRI 1250-2009 inappropriate for hot gas defrost systems. Id.
DOE stated that it is not aware of a test method that can reliably
be used to directly measure the thermal impact of hot gas defrost
without a substantial increase in test burden and mentioned that it was
therefore considering the use of a calculation method. Id. Rather than
measure the energy used and heat released into the refrigerated space
for the unit-under-test, the energy use and heat load could be
calculated as a function of the refrigeration system's steady state
capacity. Id. DOE further discussed that the energy use and heat load
to capacity relationships could be defined based on test data from
actual hot gas defrost systems. Id. DOE recognized that AHRI has
developed a calculation method to represent hot gas defrost heat load
and energy use contributions. Id. This method is provided in Section
C10.1 of AHRI 1250-2020 and prescribes equations to represent energy
use and heat addition associated with defrost for different system
configurations (matched pair, single-packaged dedicated, unit cooler,
condensing unit) and considers whether hot gas is used only to defrost
the evaporator or whether it also maintains warm temperatures in the
drip pan.
Finally, DOE discussed that if it were to amend its walk-in
refrigeration systems test procedure to account for hot gas defrost
energy consumption and heat load, DOE would need to decide if all
refrigeration system configurations (i.e., matched pairs, unit coolers
tested alone, and dedicated condensing units tested alone) would be
subject to a hot gas defrost-specific test procedure. Id.
In their comments, AHRI, Lennox, Keeprite, Hussmann, and National
Refrigeration each recommended that DOE utilize the AHRI 1250-2020 hot
gas defrost calculations for all equipment
[[Page 23970]]
types, since matched pairs, unit coolers, and dedicated condensing
units may be associated with hot gas defrost. (AHRI, No. 11 at pp. 13-
14; Lennox, No. 9 at pp. 8-9; Keeprite, No. 12 at p. 2; Hussmann, No.
18 at pp. 15-16; National Refrigeration, No. 17 at p. 2) ASAP also
supported the adoption of the hot gas defrost calculations in AHRI
1250-2020 but did not specify for which equipment systems. (ASAP, No.
13 at p. 2) NEEA observed that AHRI 1250-2020 provides both a
calculation approach and a test method to account for hot gas defrost
energy and recommended that DOE proceed with the hot gas defrost
calculations in AHRI 1250-2020 in addition to including the hot gas
defrost challenge test in Appendix F of AHRI 1250-2020. (NEEA, No. 16
at p. 3) In spite of its inability to capture frost load conditions,
the CA IOUs nevertheless supported the use of AHRI 1250-2020 Appendix F
since it captures hot gas defrost energy use. (CA IOUs, No. 14 at p. 2)
Both NEEA and the CA IOUs observed that additional work is needed to
develop a robust test method to evaluate how hot gas defrost impacts
equipment energy consumption and NEEA recommended that DOE continue to
work with industry groups to develop such a procedure. (NEEA, No. 16 at
p. 3; CA IOUs, No. 14 at p. 2)
After reviewing the comments submitted by AHRI, Lennox, Keeprite,
Hussmann and National Refrigeration, DOE has tentatively determined
that all refrigeration system configurations (i.e., matched pairs, unit
coolers tested alone, and dedicated condensing units tested alone) can
benefit from hot gas defrost. For this reason, DOE proposes that all
system configurations (when equipped with hot gas defrost) should be
eligible for a hot gas defrost ``credit,'' which will be discussed in
more detail in the following paragraphs.
As discussed previously, there is currently no industry-accepted
test method that can measure the heat load addition coming from hot gas
defrost operation. In the absence of such a method, DOE is not able to
propose a hot gas defrost testing-based method at this time. However,
if the walk-in industry develops such a method in the future, DOE may
evaluate that method's appropriateness in a future rulemaking.
While all stakeholders support a calculation-based approach using
the hot gas defrost equations in AHRI 1250-2020, DOE's goal in the
December 2016 final rule was to provide calculations for rating hot gas
defrost unit coolers using modified default values for energy use and
heat load contributions that would make their ratings more consistent
with those of electric defrost unit coolers. 81 FR 95758, 95776. The
March 2021 final rule sought to maintain this consistency between units
configured with hot gas defrost or electric defrost and ultimately
included the equations in Section C10.2 of AHRI 1250-2020 for
representing the defrost energy use and thermal load associated with
hot gas defrost systems. 86 FR 16027, 16032. DOE proposes to maintain
this calculation equivalence between hot gas defrost and electric
defrost systems. Specifically, for rating and certification, all walk-
in refrigeration systems would utilize the default values for energy
use and heat load for dedicated condensing units tested alone with
electric defrost systems. AHRI 1250-2020, Section 10.2.2.
However, like the approach discussed previously for adaptive
defrost systems, DOE is proposing that manufacturers may account for a
unit's potential improved performance with hot gas defrost in its
market representations. In other words, DOE proposes that manufacturers
may apply a hot gas defrost ``credit'' in their market representations
but must certify hot gas defrost units using the default electric
defrost equations. As mentioned previously, AHRI has developed specific
equations for determining the defrost energy and heat load associated
with hot gas defrost. AHRI 1250-2020, Section C10.1. DOE proposes that
the hot gas defrost ``credit'' may be used in marketing materials for
all refrigeration system configurations sold with hot gas defrost
(i.e., matched pairs, unit coolers tested alone, and dedicated
condensing units tested alone).
9. Refrigerant Glide
In the June 2021 RFI, DOE discussed that it was considering
changing its test procedure to a more refrigerant-neutral approach--
specifically, DOE discussed that it was considering approaches that
would more accurately represent the performance of zero-, low-, and
high-glide refrigerants. 86 FR 32332, 32351. Refrigerant glide refers
to the increase in temperature at a fixed pressure as liquid
refrigerant vaporizes during its conversion from saturated liquid (at
its bubble point) to saturated vapor (at its dew point). R-404A--a
common walk-in refrigerant--has very little glide, while R-407A--
another common walk-in refrigerant--can exhibit glide of up to 8
[deg]F.\58\
---------------------------------------------------------------------------
\58\ As noted in the June 2021 RFI, on July 20, 2015, the U.S.
Environmental Protection Agency (``EPA'') published a final rule
under the Significant New Alternatives Policy (``SNAP'') program
listing the use of certain hydrofluorocarbons (``HFCs'') as
unacceptable, including the use of R-404A in WICF refrigeration
systems. 80 FR 42870 (``July 2015 EPA SNAP Rule''). On December 1,
2016, EPA published a final rule (``December 2016 EPA SNAP Rule'')
which listed a number of refrigerants, included R-407A, for use in
certain refrigerant applications as unacceptable starting January 1,
2023 for cold storage warehouse application, and January 1, 2021,
for retail food refrigerant applications. 81 FR 86778. In August
2017, the U.S. Court of Appeals for the District of Columbia Circuit
vacated and remanded the July 2015 EPA SNAP Rule to the extent that
it required manufacturers to replace HFCs with a substitute
substance. (Mexichem Fluor, Inc. v. EPA, Case No. 15-1328 (D.C. Cir.
August 8, 2017)) A petition for rehearing has been filed by a number
of parties. (D.C. Cir., Consolidated Case Nos. 15-1328, 15-1329).
That petition for rehearing was denied on January 26, 2018.
Additionally, in October 2016, the 28th Meeting of the Parties
to the Montreal Protocol adopted the Kigali Amendment on HFCs. The
Kigali Amendment enters into force on January 1, 2019, and it
requires parties to the protocol to reduce consumption and
production of HFCs. DOE understands that, while the United States
has not yet ratified the Kigali Amendment, a significant portion of
WICFs currently use HFC-based refrigerants and may become affected
by this Amendment to the Montreal Protocol.
DOE plans to consider the potential impact of the court's
decision and the Amendment to the Montreal Protocol in this
rulemaking as appropriate.
---------------------------------------------------------------------------
The current DOE test procedure specifies unit cooler test
conditions based on the dew point at the evaporator exit. For zero-
glide refrigerants, the average evaporator temperature will typically
be equivalent to the specified dew point. However, for high-glide
refrigerants, the average evaporator temperature will be significantly
lower than the dew point since the refrigerant temperature will
increase (up to the dew point) as it travels through the evaporator. As
a result, two identical unit coolers, one charged with R-404A and one
with R-407A, will be tested at different evaporator-to-air temperature
differences (``TD''), but with the same evaporator airflow. Measured
capacity is directly correlated with the product of TD and airflow;
therefore, the high-glide R-407A unit cooler would achieve a higher
rated capacity than the R-404A unit cooler. However, this capacity
difference is an artifact of the test procedure, which requires that
unit coolers and dedicated condensing units be tested alone. In the
field, a unit cooler will be paired with a dedicated condensing unit
and R-407A unit coolers will not actually provide additional capacity
when compared to their R-404A counterparts.
For these reasons, the current test procedure is not refrigerant-
neutral. In the June 2021 RFI, DOE discussed the possibility of
pursuing a modified midpoint approach, which DOE believed may be more
refrigerant-neutral. 86 FR 32332, 32355. The modified midpoint approach
attempts to standardize the average evaporator
[[Page 23971]]
temperature, rather than standardizing the evaporator dew point. In
doing so, identical unit coolers using zero- and high-glide
refrigerants would exhibit identical TDs, thus alleviating concerns of
overstated capacity. DOE requested comment on the appropriateness of a
modified midpoint approach and how such a method could be implemented
in the June 2021 RFI. 86 FR 32332, 32355. Lennox, AHRI, Keeprite,
National Refrigeration, and Hussmann recommended maintaining the
current dew point approach since dewpoint is measurable and the
approach is accepted in the industry. (Lennox, No. 9 at p. 11; AHRI,
No. 11 at p. 16; Keeprite, No. 12 at p. 3; National Refrigeration, No.
17 at p. 2; Hussmann, No. 18 at p. 20) Lennox, AHRI, and Hussmann also
stated that dew point is a required reference for dual instrumentation
evaporator superheat calculations and can be measured during
installation and service. (Lennox, No. 9 at p. 11; AHRI, No. 11 at p.
16; Hussmann, No. 18 at p. 20) Keeprite claimed that a midpoint or
corrected midpoint approach is unproven and is not measurable.
(Keeprite, No. 12 at p. 3) Keeprite additionally added that a change
from dewpoint to midpoint may have large effects on unit cooler AWEF
values. Id. Daikin stated that engineers use the mean value between dew
point and bubble point when designing refrigeration systems since this
approach simplifies energy calculations. (Daikin, No. 17 at p. 4)
DOE acknowledges the potential increased testing burden highlighted
by manufacturers if a modified midpoint were to be adopted. In response
to these comments DOE proposes to continue to use dewpoint throughout
the test procedure but will continue to evaluate the potential for
using a midpoint in testing.
10. Refrigerant Temperature and Pressure Instrumentation Locations
In the June 2021 RFI, DOE requested comment on changes between AHRI
1250-2020 and AHRI 1250-2009 which may impact the determination of AWEF
or increase the testing burden. 86 FR 32332, 32336. In response to this
request AHRI, Lennox, and Hussmann stated that the test set-up for DX
Dual instrumentation method for testing dedicated condensing units
alone has changed, represented by Figure C1 in AHRI 1250-2009, and the
new Figure C2 in AHRI 1250-2020. The commenters stated that this
changes the location of the instrumentation for pressure and
temperature measurement. Additionally, they stated that the new method
removes the alternative location of the second mass flow meter and
claim that both sets of changes necessitate changes in lab test stands.
Further, the commenters claimed that AHRI 1250-2020 added a change to
the refrigeration capacity calculation for dedicated condensing units,
whereby the enthalpy representing the refrigerant at the evaporator
exit condition has changed such that it is based on a pressure
corresponding to a dew point 2 [deg]F higher than at the condensing
unit inlet and a superheat of 6.5 [deg]F. (Lennox, No. 9 at p. 3; AHRI,
No. 11 at p. 5; Hussmann, No. 18 at p. 7) The same group of commentors
stated these locations are now different than those specified for
matched pair testing, and the DX Calibrated Box method. Id.
DOE notes first that AHRI 1250-2009 does not provide a test method
for dedicated condensing units tested alone, other than incorporating
by reference ASHRAE 23-2005 (see Section C12 of AHRI 1250-2009 appendix
C). ASHRAE 23 calls for calculating capacity by multiplying the
refrigerant mass flow rate by the difference in enthalpies. However,
the current DOE test procedure clarifies which values of pressure and
temperature are used to determine the enthalpies to use for this
capacity calculation--this is specified in section 3.4.2.1 of subpart
R, appendix C. The section indicates that, for enthalpy leaving the
unit cooler, the calculation uses a pressure corresponding to a dew
point temperature of 25 [deg]F and a temperature of 35 [deg]F for
coolers, and a dew point of -20 [deg]F and temperature of -14 [deg]F
for freezers. These dew points are identical to the dew points
specified in AHRI 1250-2020.\59\ The temperatures represent superheat
levels equal to 10 [deg]F for coolers and 6 [deg]F for freezers, which
are different than the 6.5 [deg]F specified in Section C7.5.2 of AHRI
1250-2020. Section 3.4.2.1 of subpart R, appendix C, also indicates
that in the current DOE test procedure, the measured enthalpy at the
condensing unit exit shall be used as the enthalpy entering the unit
cooler. This is consistent with Figure C2 and Section C7.5.1.1.2 of
AHRI 1250-2020. Thus, the only difference in AHRI 1250-2020 affecting
the dedicated condensing unit efficiency calculations is the change in
specified superheat, and there is no effective difference in the
location of required pressure and temperature measurements. DOE will
address the calculation change and other test procedure changes that
can alter the measurement in an energy conservation standards
rulemaking.
---------------------------------------------------------------------------
\59\ For example, for coolers, Tables 12 and 13 of AHRI 1250-
2020 require that CDU suction dew point be 23 [deg]F, while section
C7.5.2 indicates that the enthalpy to use in the calculation of
capacity shall be for a pressure corresponding to dew point 2 [deg]F
higher than for the recorded pressure at the inlet of the dedicated
condensing unit.
---------------------------------------------------------------------------
The comments of AHRI, Lennox, and Hussmann also address the test
burden of not allowing the use of the alternative second location of
the mass flow meter. (AHRI, No. 11 at pp. 5-6; Lennox, No. 9 at p. 3;
Hussmann, No. 18 at p. 7 The comments provided no indication that use
of a mass flow meter in the suction line should not be allowed. Hence,
DOE proposes to clarify that the location of the second mass flow meter
in the suction line would still be allowed. This proposal would
eliminate the potential costs associated with Figure C2's suggestion
that use of a suction line mass flow meter is not allowed.
Issue 29: DOE requests comment on its proposal to clarify that the
second mass flow measurement for the DX Dual Instrumentation method may
be in the suction line upstream of the inlet to the condensing unit, as
shown in Figure C1 of AHRI 1250-2009.
11. Updates to Default Values for Unit Cooler Parameters
For dedicated condensing units tested alone, the current DOE test
procedure calculates on-cycle evaporator fan power based on the cooling
capacity of the condensing unit. This is necessary as a dedicated
condensing unit tested alone will have no measured value for evaporator
fan power. The on-cycle evaporator fan power is set equal to a fraction
of the gross cooling capacity. The fraction is specified by a
coefficient of .013 for medium temperature coolers and a coefficient of
.016 for low temperature coolers. These coefficients were a product of
the 2016 rulemaking negotiations. As discussed in section III.B.3.c,
Sections 7.9.1 and 7.9.2 of AHRI 1250-2020 add new equations to
calculate on-cycle evaporator fan power when testing a dedicated
condensing unit alone. These equations are different from those in the
current test procedure at subpart R, appendix C. The equations in AHRI
1250-2020 are split based on low versus medium temperature dedicated
condensing units, and the capacity of the dedicated condensing units.
Those units over 50,000 Btu/h have one equation and those under 50,000
Btu/h that capacity have another, resulting in 4 equations total. These
equations are based on more test data and analysis than those currently
in subpart R, appendix C. DOE has tentatively determined that these
equations would be more representative, and do not pose a greater test
burden. Therefore, DOE proposes to adopt the calculations for on-cycle
evaporator fan
[[Page 23972]]
power for dedicated condensing units tested alone in AHRI 1250-2020.
Issue 30: DOE requests comment on its proposal to adopt the
calculations for evaporator fan power in AHRI 1250-2020.
12. Calculations and Rounding
To ensure greater test procedure consistency, DOE is proposing to
include rounding requirements for AWEF and capacity in the newly
proposed appendix C1. DOE notes that AHRI 1250-2020 does not include
requirements for rounding these values. DOE recognizes that the manner
in which values are rounded can affect the resulting capacity and AWEF
values. To ensure consistency in the manner in which capacity and AWEF
values are calculated, DOE is proposing that raw measured data would be
used in all capacity and AWEF calculations. DOE's current standards
specify a minimum AWEF value in Btu/(W-h) to the hundredths place;
therefore, DOE is proposing that AWEF values would be rounded to the
nearest 0.05 Btu/(W-h). To round capacity, DOE is proposing to round to
the nearest multiple as specified in Table III.14. The proposed
capacity bins and multiples are consistent with other HVAC test
procedures.\60\
---------------------------------------------------------------------------
\60\ A version of Table III.9 can be found in AHRI Standard 390
I-P (2021) ``Performance Rating of Single-packaged Vertical Air-
Conditioners and Heat Pumps.''
Table III.14--Refrigeration Capacity Rating Ranges and Their Rounding
Multiples
------------------------------------------------------------------------
Multiples, Btu/
Refrigeration capacity ratings, 1,000 Btu/h h
------------------------------------------------------------------------
<20..................................................... 100
>=20 and <38............................................ 200
>=38 and <65............................................ 500
>=65.................................................... 1,000
------------------------------------------------------------------------
Issue 31: DOE requests comment on its proposal for rounding AWEF to
the nearest 0.05 Btu/(W-h) and rounding capacity values to the nearest
multiple as presented in Table III.14.
H. Alternative Efficiency Determination Methods
Pursuant to the requirements of 10 CFR 429.70, DOE may permit use
of an alternative efficiency determination method (``AEDM'') in lieu of
testing equipment for which testing burden may be considerable and for
which that equipment's energy efficiency performance may be well
predicted by such alternative methods. Although specific requirements
vary by product or equipment, use of an AEDM entails development of a
mathematical model that estimates energy efficiency or energy
consumption characteristics of the basic model, as would be measured by
the applicable DOE test procedure. The AEDM must be based on
engineering or statistical analysis, computer simulation or modeling,
or other analytic evaluation of performance data. A manufacturer must
perform validation of an AEDM by demonstrating that the performance, as
predicted by the AEDM, is in agreement with the performance as measured
by actual testing in accordance with the applicable DOE test procedure.
The validation procedure and requirements, including the statistical
tolerance, number of basic models, and number of units tested vary by
product or equipment.
Once developed, an AEDM may be used to rate and certify the
performance of untested basic models in lieu of physical testing.
However, use of an AEDM for any basic model is always at the option of
the manufacturer. One potential advantage of AEDM use is that it may
free a manufacturer from the burden of physical testing. One potential
risk is that the AEDM may not perfectly predict performance, and the
manufacturer could be found responsible for having an invalid rating
for the equipment in question or for having distributed a noncompliant
basic model. The manufacturer, by using an AEDM, bears the
responsibility and risk of the validity of the ratings. For walk-ins,
DOE currently permits the use of AEDMs for refrigeration systems only.
10 CFR 429.70(f).
The following sections discuss DOE's proposal to allow walk-in door
manufacturers to use AEDMs to rate both display and non-display doors,
as well as proposed updates to the current AEDM provisions for
refrigeration systems.
1. Doors
DOE did not adopt provisions allowing for the use of AEDMs for
walk-in doors in the May 2014 rule because DOE found that the modeling
techniques approved for use in the NFRC 100 test procedure
(incorporated by reference at 10 CFR 431.303) made a parallel AEDM
provision for walk-in doors unnecessary. 79 FR 27388, 27394. Consistent
with DOE's proposal to remove reference to NFRC 100 (and thus the
computational method) for determining U-factor of doors, DOE is
proposing to allow the use of AEDMs to determine the represented value
of energy consumption of walk-in doors at 10 CFR 429.53(a)(3).
Correspondingly, DOE is proposing to expand the AEDM provisions in 10
CFR 429.70(f) to apply to walk-in doors. DOE is proposing to include a
5 percent individual model tolerance, which aligns with the individual
model tolerance applicable to walk-in refrigeration systems, to
validate the energy consumption result of an AEDM with the appendix A
test result at 10 CFR 429.70(f)(2)(ii). DOE also proposes that an AEDM
for doors may not simulate or model components of the door that are not
required to be tested by the DOE test procedure. If the test results
used to validate the AEDM are for the U-factor test of the door, the
AEDM must estimate the daily energy consumption--specifically, the
conduction thermal load, and the direct and indirect electrical energy
consumption, by using the nominal values (e.g., EER values used for
coolers and freezers, PTO values) and calculation procedure specified
in the DOE test procedure. Additionally, DOE is proposing to include
walk-in door validation classes at 10 CFR 429.70(f)(2)(iv) and to
require that two basic models per validation class be tested using the
proposed test procedure in appendix A, which is consistent with the
number of basic models required to be tested per validation class for
walk-in refrigeration systems. Lastly, DOE is proposing to include a 5
percent tolerance applicable to the maximum daily energy consumption
metric for AEDM verification testing at 10 CFR 429.70(f)(5)(vi), which
aligns with the tolerance applicable to AWEF of walk-in refrigeration
systems.
Issue 32: DOE seeks comment on its proposal to allow for the use of
AEDMs to determine the energy consumption rating of walk-in doors. DOE
requests specific feedback on the proposed 5 percent model tolerance
for validating an AEDM, the proposed validation classes and number of
basic models required to be tested per validation class, and the
proposed 5 percent tolerance on the result from a DOE AEDM verification
test.
2. Refrigeration Systems
In the May 2014 final rule, DOE established that AEDMs can be used
by manufacturers of refrigeration systems, once certain qualifications
are met, to certify compliance and report ratings. 79 FR 27388, 27389.
That rule established a uniform, systematic, and fair approach to the
use of these types of modeling techniques that has enabled DOE to
ensure that products in the marketplace are correctly rated--
irrespective of whether they are subject to actual physical testing or
are rated using
[[Page 23973]]
modeling--without unnecessarily burdening regulated entities. Id.
A minimum of two distinct models must be tested to validate an AEDM
for each validation class. The May 2014 final rule established the
following AEDM validation classes for walk-ins:
Dedicated condensing units, medium temperature, indoor
system;
Dedicated condensing units, medium temperature, outdoor
system;
Dedicated condensing units, low temperature, indoor
system;
Dedicated condensing units, low temperature, outdoor
system;
Unit cooler connected to a muliplex condensing unit,
medium temperature;
Unit cooler connected to a multiplex condensing unit, low
temperature;
Medium temperature, indoor condensing unit;
Medium temperature, outdoor condensing unit;
Low temperature, indoor condensing unit;
Low temperature, outdoor condensing unit.
See 79 FR 27388, 27411 (codified at 10 CFR 429.70(f)(5)(iv)).
In this NOPR, DOE is proposing new test procedures for single-
packaged refrigeration systems, high-temperature refrigeration systems,
and CO2 unit coolers. Temperature has a significant impact
on equipment performance; therefore, DOE is proposing to incorporate
new AEDM validation classes for all high-temperature refrigeration
systems (dedicated condensing units, single-packaged dedicated systems,
and matched pair systems). Additionally, single-packaged units are
expected to perform differently than dedicated condensing units under
the proposed test procedure which incorporates thermal losses.
Therefore, DOE proposes to create new validation classes for low-
temperature, medium-temperature, and high-temperature single-packaged
dedicated systems. To ensure that walk-in validation classes are
consistent with DOE's current walk-in terminology, DOE proposes to
rename the ``unit cooler connected to a multiplex condensing unit''
validation classes to ``unit cooler'' at either medium- or low-
temperature; however, the AEDM requirements for theses classes remain
the same. Finally, DOE proposes to remove the medium/low temperature
indoor/outdoor condensing unit validation classes, as these are
redundant with the medium/low temperature indoor/outdoor dedicated
condensing unit validation classes.
As discussed, DOE proposes to reference in appendix C1 the methods
of test for single-packaged dedicated systems in Section C9 of AHRI
1250-2020, with some modifications. Implementation of appendix C1, if
finalized, would require that all AEDMs for single-packaged dedicated
systems are amended to be consistent with the test procedure proposed
in appendix C1.
In summary, DOE is proposing the following AEDM validation classes
for walk-in refrigeration equipment:
Dedicated Condensing Unit, Medium Temperature, Indoor
System
Dedicated Condensing Unit, Medium Temperature, Outdoor
System
Dedicated Condensing Unit, Low Temperature, Indoor System
Dedicated Condensing Unit, Low Temperature, Outdoor System
Single-packaged Dedicated System, High-temperature, Indoor
System
Single-packaged Dedicated System, High-temperature,
Outdoor System
Single-packaged Dedicated System, Medium Temperature,
Indoor System
Single-packaged Dedicated System, Medium Temperature,
Outdoor System
Single-packaged Dedicated System, Low Temperature, Indoor
System
Single-packaged Dedicated System, Low Temperature, Outdoor
System
Matched Pair, High-temperature, Indoor Condensing Unit
Matched Pair, High-temperature, Outdoor Condensing Unit
Matched Pair, Medium Temperature, Indoor Condensing Unit
Matched Pair, Medium Temperature, Outdoor Condensing Unit
Matched Pair, Low Temperature, Indoor Condensing Unit
Matched Pair, Low Temperature, Outdoor Condensing Unit
Unit Cooler, High-temperature
Unit Cooler, Medium Temperature
Unit Cooler, Low Temperature
DOE would maintain its provision that outdoor models that are
within a given validation class may be used to determine represented
values for the corresponding indoor class, and additional validation
testing is not required. For example, two dedicated condensing unit,
medium temperature, outdoor systems may be used to validate an AEDM for
both the ``Dedicated Condensing Unit, Medium Temperature, Outdoor
System'' class and the ``Dedicated Condensing Units, Medium
Temperature, Indoor System'' class. If indoor models that fall within a
given validation class are tested and used to validate an indoor AEDM,
they may only be used for that validation class.
DOE is proposing no additional modifications to the provisions
within 10 CFR 429.70(f).
Issue 33: DOE seeks comment on its proposal to modify and extend
its AEDM validation classes for refrigeration systems, consistent with
the test procedure revisions discussed in this document.
I. Sampling Plan for Enforcement Testing
When DOE conducts enforcement testing of equipment, DOE uses one of
the enforcement sampling plans in appendix A or B to subpart C of 10
CFR part 429 to calculate upper control limits and lower control limits
around the standard value based on the standard deviation of the test
sample. These statistics are applied to the test results in the sample
to determine compliance or non-compliance. DOE uses appendix B to
subpart C of 10 CFR part 429 to assess compliance for walk-in
refrigeration systems, which is specifically intended for use for
covered equipment and certain low-volume covered products. 10 CFR
429.110(e)(2). DOE does not specifically call out which appendix in
subpart C of 10 CFR part 429 it uses for determination of compliance
for walk-in doors or walk-in panels. In an Enforcement NOPR published
on August 31, 2020 (``August 2020 Enforcement NOPR''), DOE proposed to
add walk-in cooler and freezer doors and panels to the list of
equipment subject to the low-volume enforcement sampling procedures in
appendix B to subpart C of 10 CFR part 429. 85 FR 53691, 53696. DOE
noted that this equipment is not currently included within DOE's list
because when the current regulations were drafted, walk-in doors and
walk-in panels did not have applicable performance standards, only
design standards, and therefore sampling provisions were not necessary
at the time. Id. DOE did not receive any comments in response to this
proposal in the August 2020 Enforcement NOPR. DOE is therefore
proposing in this document to include walk-in doors and walk-in panels
in the list of low-volume products 10 CFR 429.110(e)(2).
Issue 34: DOE requests comment on its proposal to apply the low-
volume sampling procedures in appendix B of subpart C of 10 CFR part
429 to walk-in doors and panels.
J. Test Procedure Costs and Impact
EPCA requires that test procedures proposed by DOE be reasonably
designed to produce test results which reflect energy efficiency and
energy use of a type of industrial equipment during a representative
average use cycle and not be unduly burdensome to conduct. (42 U.S.C.
6314(a)(2)) The following sections discuss DOE's evaluation of the
estimated costs and savings associated
[[Page 23974]]
with the amendments proposed in this NOPR. The following sections
outline the potential costs and savings differentiated by WICF
component: Doors, panels, and refrigeration systems.
1. Doors
In this NOPR, DOE proposes the following amendments to the test
procedures for walk-in cooler and freezer doors:
1. Referencing NFRC 102-2020 for the determination of U-factor;
2. Including AEDM \61\ provisions for manufacturers to
alternately determine the total energy consumption of display and
non-display doors;
---------------------------------------------------------------------------
\61\ As already noted elsewhere in this document, an AEDM is a
computer modeling or mathematical tool that predicts the performance
of non-tested basic models. These computer modeling and mathematical
tools, when properly developed, can provide a means to predict the
energy usage or efficiency characteristics of a basic model of a
given covered product or equipment and reduce the burden and cost
associated with testing.
---------------------------------------------------------------------------
3. Providing additional detail for determining the area used to
convert U-factor into conduction load, As, to differentiate it from
the area used to determine compliance with the standards, Add or
And; and
4. Specifying a PTO value of 97 percent for door motors.
Items 1 and 3, referencing NFRC 102-2020 and additional detail on
the area used to convert U-factor into a conduction load, improves the
consistency, reproducibility, and representativeness of test procedure
results. Item 2, including AEDM provisions, intends to provide
manufacturers with the flexibility to use an alternative method that
gives the best agreement for their doors. Item 4, by proposing to
include a PTO value of 97 percent, intends to provide a more
representative and consistent means for comparison of walk-in door
performance for doors with motors.
DOE has tentatively determined that these proposed amendments would
improve the representativeness, accuracy, and reproducibility of the
test results, and would not be unduly burdensome for door manufacturers
to conduct. DOE has also tentatively determined that these proposed
amendments would not increase testing costs per basic model relative to
the current DOE test procedure in appendix A, which DOE estimates to be
$10,000 for third-party labs to determine energy consumption of a walk-
in door, including physical U-factor testing per NFRC 102-2020.\62\ DOE
has tentatively determined that manufacturers would not be required to
redesign any of the covered equipment or change how the equipment is
manufactured, solely as result of the proposed amendments, if
finalized.
---------------------------------------------------------------------------
\62\ DOE estimates the cost of one test to determine energy
consumption of a walk-in door, including one physical U-factor test
per NFRC 102-2020 to be $5,000. Per the sampling requirements
specified at 10 CFR 429.53(a)(3)(ii) and 10 CFR 429.11(b),
manufacturers are required to test at least two units to determine
the rating for a basic model, except where only one unit of the
basic model is produced.
---------------------------------------------------------------------------
The cost impact to manufacturers as a result of the reference to
NFRC 102-2020 and inclusion of AEDM provisions is dependent on the
agreement between tested and simulated values as specified in Section
4.7.1 of NFRC 100 \63\ as referenced in the current test procedure. For
manufacturers of doors that have been able to achieve the specified
agreement between U-factors simulated using the method in NFRC 100 and
U-factors tested using NFRC 102, manufacturers would be able to
continue using the simulation method in NFRC 100, provided that the
simulation method also meets the basic requirements proposed for an
AEDM in 10 CFR 429.53 and 10 CFR 429.70(f).
---------------------------------------------------------------------------
\63\ Section 4.7.1 of NFRC 100 requires that the accepted
difference between the tested U-factor and the simulated U-factor be
(a) 0.03 Btu/(h-ft2 [deg]F) for simulated U-factors that are 0.3
Btu/(h-ft\2\-[deg]F) or less, or (b) 10 percent of the simulated U-
factor for simulated U-factors greater than 0.3 Btu/(h-ft\2\-
[deg]F). This agreement must match for the baseline product in a
product line. Per NFRC 100, the baseline product is the individual
product selected for validation; it is not synonymous with ``basic
model'' as defined in 10 CFR 431.302.
---------------------------------------------------------------------------
For manufacturers of doors that have not been able to achieve the
specified agreement between U-factors simulated using the method in
NFRC 100 and U-factors tested using NFRC 102, DOE estimates that the
test burden would decrease. Under the current requirements,
manufacturers may be required to determine U-factor through physical
testing of every basic model. If the proposed test procedure were to be
adopted, manufacturers who would have otherwise been required to
physically test every walk-in door basic model could develop an AEDM
for rating their basic models of walk-in doors consistent with the
proposed provisions in 10 CFR 429.53 and 10 CFR 429.70(f). DOE
estimates the per-manufacturer cost to develop and validate an AEDM for
a single validation class of walk-in doors to be $11,100. DOE estimates
an additional cost to determine energy consumption of a walk-in door
using an AEDM to be $46 per basic model.\64\
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\64\ DOE estimated initial costs to validate an AEDM assuming 24
hours of general time to develop and validate an AEDM based on
existing simulation tools. DOE estimated the cost of an engineering
calibration technician fully burdened wage of $46 per hour plus the
cost of third-party physical testing of two basic models per
proposed validation class. DOE estimated the additional per basic
model cost to determine efficiency using an AEDM assuming 1 hour per
basic model at the cost of an engineering calibration technician
wage of $46 per hour.
---------------------------------------------------------------------------
DOE expects that the additional detail provided for determining the
area used to convert U-factor into conduction load, As, would either
result in a reduced energy consumption or have no impact. To the extent
that this change to the test procedure would amend the energy
consumption attributable to a door, such changes would either not
change the calculated energy consumption or result in a lower energy
consumption value as compared to how manufacturers may currently be
rating given that the current test procedure does not provide specific
details on measurement of Add or And. As such, DOE expects that
manufacturers would be able to rely on data generated under the current
test procedure. While manufacturers must submit a report annually to
certify a basic model's represented values, basic models do not need to
be retested annually. The initial test results used to generate a
certified rating for a basic model remain valid as long as the basic
model has not been modified from the tested design in a way that makes
it less efficient or more consumptive, which would require a change to
the certified rating. If a manufacturer has modified a basic model in a
way that makes it more efficient or less consumptive, new testing is
only required if the manufacturer wishes to make claims of the new,
more efficient rating.\65\
---------------------------------------------------------------------------
\65\ See guidance issued by DOE at: www1.eere.energy.gov/buildings/appliance_standards/pdfs/cert_faq_2012-04-17.pdf.
---------------------------------------------------------------------------
For doors without motors, DOE has tentatively concluded that the
proposed test procedure would not change energy consumption ratings,
and therefore would not require re-rating solely as result of DOE's
adoption of this proposed amendment to the test procedure. Therefore,
DOE has determined the proposed amendments either decrease or result in
no additional testing costs to manufacturers of walk-in doors.
To the extent that changes to the test procedure would amend the
energy consumption attributable to a door motor, such changes would
either not change the calculated energy consumption or result in a
lower energy consumption value as compared to the currently granted
waivers addressing door motors. As such, DOE expects that manufacturers
would be able to rely on data generated under the current test
procedure and current waivers. While manufacturers must submit a report
annually to certify a basic model's represented values, basic models do
not
[[Page 23975]]
need to be retested annually. The initial test results used to generate
a certified rating for a basic model remain valid as long as the basic
model has not been modified from the tested design in a way that makes
it less efficient or more consumptive, which would require a change to
the certified rating. If a manufacturer has modified a basic model in a
way that makes it more efficient or less consumptive, new testing is
only required if the manufacturer wishes to make claims of the new,
more efficient rating.\66\
---------------------------------------------------------------------------
\66\ See guidance issued by DOE at: www1.eere.energy.gov/buildings/appliance_standards/pdfs/cert_faq_2012-04-17.pdf.
---------------------------------------------------------------------------
Issue 35: DOE requests comment on its tentative understanding of
the impact of the test procedure proposals for appendix A in this
NOPR--specifically, whether the proposed test procedure amendments, if
finalized, would either not impact or decrease the testing burden for
walk-in door manufacturers when compared to the current DOE test
procedure in appendix A.
2. Panels
In this NOPR, DOE proposes to amend the existing test procedure in
appendix B for measuring the R-value of insulation of panels by:
1. Incorporating by reference the updated version of the applicable
industry test method, ASTM C518-17;
2. Including provisions specific to measurement of test specimen
and total insulation thickness; and
3. Providing guidance on determining the parallelism and flatness
of the test specimen.
Item 1 incorporates by reference the most up to date version of the
industry standards currently referenced in the DOE test procedure.
Items 2 and 3 include additional instructions intended to improve
consistency and reproducibility of test procedure results. DOE has
tentatively determined that these proposed amendments would improve the
accuracy and reproducibility of the test results and would not be
unduly burdensome for manufacturers to conduct, nor would they be
expected to increase the testing burden.
DOE expects that the proposed test procedure in appendix B for
measuring the R-value of insulation would not increase testing costs
per basic model relative to the current DOE test procedure, which DOE
estimates to be $1,200 for third-party lab testing.\67\ Additionally,
DOE has tentatively determined that the proposed test procedure in
appendix B would not result in manufacturers having to redesign any of
the covered equipment or change how the equipment is manufactured.
Further DOE has tentatively determined that, if finalized, the proposed
amendments would not impact the utility of the equipment.
---------------------------------------------------------------------------
\67\ DOE estimates the cost of one test to determine R-value to
be $600. Per the sampling requirements specified at 10 CFR
429.53(a)(3)(ii) and 10 CFR 429.11(b), manufacturers are required to
test at least two units to determine the rating for a basic model,
except where only one unit of the basic model is produced.
---------------------------------------------------------------------------
Issue 36: DOE requests comment on its tentative understanding of
the impact of the test procedure proposals for appendix B in this
NOPR--specifically, that the proposed test procedure amendments, if
finalized, would not increase testing burden on panel manufacturers
when compared to the current DOE test procedure in appendix B.
3. Refrigeration Systems
In this NOPR, DOE proposes certain changes to subpart R, appendix
C, that DOE has tentatively determined would improve the accuracy and
reproducibility of the test results and would not be unduly burdensome
for manufacturers to conduct. DOE has tentatively determined that these
proposed changes would not impact testing cost. Additionally, the
proposed amended subpart R, appendix C, measuring AWEF per AHRI 1250-
2009, does not contain any changes that would require retesting or
rerating if it were to be adopted. DOE's tentative assessment of the
impacts of the proposed amendments of subpart R, appendix C, to include
new test procedures for high-temperature refrigeration systems and
CO2 unit coolers are discussed in more detail below.
DOE also proposes to adopt certain changes in the newly proposed
appendix C1 that would amend the existing test procedure for walk-in
coolers and freezers by:
1. Expanding the off-cycle refrigeration system power measurements;
2. Adding methods of test for single-packaged dedicated systems;
and
3. Including a method for testing ducted systems.
DOE has tentatively determined that these proposed amendments would
improve the representativeness, accuracy, and reproducibility of the
test results, and would not be unduly burdensome for manufacturers to
conduct. DOE has also tentatively determined that these proposed
amendments would impact testing costs by equipment type. DOE does not
anticipate that the remainder of the amendments proposed in this NOPR
would impact test costs or test burden.
DOE estimates third-party test costs for testing to the current DOE
test procedure to be:
$10,000 for outdoor low-temperature and medium-temperature
dedicated condensing units tested alone
$6,500 for indoor low temperature and medium temperature
dedicated condensing units tested alone
$6,500 for low-temperature unit coolers tested alone
$6,000 for medium-temperature unit coolers tested alone
$10,000 for single-packaged dedicated systems
$10,000 for high-temperature matched pairs
As discussed previously in section III.G.1 of this document, DOE is
proposing to adopt off-cycle test provisions in AHRI 1250-2020 for
walk-in cooler and freezer refrigeration systems. The current test
procedure requires off-cycle power to be measured at the 95 [deg]F
ambient condition. The proposed test procedure requires off-cycle to be
measured at 95 [deg]F, 59 [deg]F, and 35 [deg]F ambient conditions for
outdoor dedicated condensing units, outdoor matched pair systems, and
outdoor dedicated systems. The matched pair and single-packaged
dedicated systems include high-temperature refrigeration systems. When
the waivers for these high-temperature refrigeration systems were
granted, only one off-cycle test was required; therefore, manufacturers
with waivers would be required to conduct additional testing as
compared to the alternate test procedure currently required. DOE
estimates that measuring off-cycle power at these additional ambient
conditions may increase per-unit third-party lab test cost by $1,000
per unit to a total cost of $11,000 per unit for outdoor dedicated
condensing units, outdoor matched pair systems, and outdoor single-
packaged dedicated systems.
Manufacturers are not required to perform laboratory testing on all
basic models. In accordance with 10 CFR 429.53, WICF refrigeration
system manufacturers may elect to use AEDMs. DOE estimates the per-
manufacturer cost to develop and validate an AEDM for outdoor dedicated
condensing units and outdoor matched pair systems to be $24,580.\68\
DOE estimates an additional
[[Page 23976]]
cost of approximately $46 per basic model \69\ for determining energy
efficiency of a given basic model using the validated AEDM.
---------------------------------------------------------------------------
\68\ Outdoor single-packaged systems are also impacted by the
proposed adoption of AHRI 1250-2020 single-packaged test procedure
for walk-in cooler and freezer refrigeration systems. The combined
potential cost increase for outdoor single-packaged systems is
presented in the next paragraph.
\69\ DOE estimated initial costs to validate an AEDM assuming 40
hours of general time to develop an AEDM based on existing
simulation tools and 16 hours to validate two basic models within
that AEDM at the cost of an engineering calibration technician fully
burdened wage of $46 per hour plus the cost of third-party physical
testing of two units per validation class (as required in 10 CFR
429.70(c)(2)(iv)). DOE estimated the additional per basic model cost
to determine efficiency using an AEDM assuming 1 hour per basic
model at the cost of an engineering calibration technician wage of
$46 per hour.
---------------------------------------------------------------------------
As discussed previously in section III.G.2, DOE is proposing to
adopt the single-packaged dedicated system test procedure for walk-ins
in AHRI 1250-2020. The proposed procedure requires air enthalpy tests
to be used as the primary test method. In the current test procedure,
single-packaged dedicated systems use refrigerant enthalpy as the
primary test method. DOE does not estimate a difference in physical
testing costs between air and refrigerant enthalpy testing of single-
packaged units. DOE estimates the per-unit third-party lab test cost to
be $11,000 for outdoor single-packaged units and $6,500 for indoor
single-packaged units. However, should a manufacturer choose to use an
AEDM, they may incur additional costs regarding the development and
validation of new AEDMs for single-packaged dedicated systems. DOE
estimates the per-manufacturer cost to develop and validate an AEDM to
be $24,580 for outdoor single-packaged units and $15,580 for indoor
single-packaged units. DOE estimates an additional cost of
approximately $46 per basic model \70\ for determining energy
efficiency using the validated AEDM.
---------------------------------------------------------------------------
\70\ DOE estimated initial costs to validate an AEDM assuming 40
hours of general time to develop an AEDM based on existing
simulation tools and 16 hours to validate two basic models within
that AEDM at the cost of an engineering calibration technician fully
burdened wage of $46 per hour plus the cost of third-party physical
testing of two units per validation class (as required in 10 CFR
429.70(c)(2)(iv)). DOE estimated the additional per basic model cost
to determine efficiency using an AEDM assuming 1 hour per basic
model at the cost of an engineering calibration technician wage of
$46 per hour.
---------------------------------------------------------------------------
As discussed in sections III.F.6 and III.G.6, DOE is proposing test
procedures for CO2 unit coolers and high-temperature
refrigeration systems. DOE tentatively estimates that the average
third-party lab per unit test cost would be $11,000 for a high-
temperature matched pair or single-packaged system, $6,000 for a high-
temperature unit cooler tested alone, $6,500 for a low temperature
CO2 unit cooler, and $6,000 for a medium temperature
CO2 unit cooler. As discussed previously, DOE has granted
waivers to certain manufacturers for both high-temperature
refrigeration systems and CO2 unit coolers. The test
procedures proposed in this NOPR are consistent with the alternate test
procedures included in the granted waivers. For those manufacturers who
have been granted a test procedure waiver for this equipment, DOE
expects that there would be no additional test burden. However, DOE
expects that there would be additional testing costs for any
manufacturers of these products who have not submitted or been granted
a test procedure waiver at the time this proposed test procedure is
finalized. Such companies may incur an additional per unit test cost
of:
$11,000 for a high-temperature matched pair or single-
packaged system;
$6,000 for a high-temperature unit cooler tested alone;
$6,500 for a low temperature CO2 unit cooler
tested alone; and
$6,000 for a medium temperature CO2 unit cooler
tested alone.
Issue 37: DOE requests comment on its tentative understanding of
the impact of the test procedure proposals for refrigeration systems--
specifically, whether DOE's initial conclusion that the proposed DOE
test procedure amendments, if finalized, would increase testing burden.
K. Compliance Date and Waivers
EPCA prescribes that, if DOE amends a test procedure, all
representations of energy efficiency and energy use, including those
made on marketing materials and product labels, must be made in
accordance with that amended test procedure, beginning 180 days after
publication of such a test procedure final rule in the Federal
Register. (42 U.S.C. 6314(d)(1)) To the extent the modified test
procedure proposed in this document is required only for the evaluation
and issuance of updated efficiency standards, use of the modified test
procedure, if finalized, would not be required until the implementation
date of updated standards. 10 CFR 431.4; section 8(e) of appendix A 10
CFR part 430 subpart C.
If DOE were to publish an amended test procedure, EPCA provides an
allowance for individual manufacturers to petition DOE for an extension
of the 180-day period if the manufacturer may experience undue hardship
in meeting the deadline. (42 U.S.C. 6314(d)(2)) To receive such an
extension, petitions must be filed with DOE no later than 60 days
before the end of the 180-day period and must detail how the
manufacturer will experience undue hardship. Id.
Upon the compliance date of any provisions of an amended test
procedure, any waivers that are currently in effect pertaining to
issues addressed by such provisions are terminated. 10 CFR
431.401(h)(3). Recipients of any such waivers would be required to test
the products subject to the waiver according to the amended test
procedure as of the compliance date of the amended test procedure. The
amendments proposed in this document pertain to issues addressed by
waivers and interim waivers granted to the manufacturers listed in
Table III.15. The proposed amendments also address issues identified in
a pending waiver for RSG (Case No. 2022-004).\71\
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\71\ The RSG waiver docket can be found at www.regulations.gov/docket/EERE-2022-BT-WAV-0010.
Table III.15--Manufacturers Granted Waivers and Interim Waivers
----------------------------------------------------------------------------------------------------------------
Proposed test
Manufacturer Subject Case No. Relevant test procedure
procedure compliance date
----------------------------------------------------------------------------------------------------------------
Jamison Door Company............. PTO for Door Motors 2017-009 Appendix A......... 180 days after test
procedure final
rule publication.
HH Technologies.................. PTO for Door Motors 2018-001 Appendix A......... 180 days after test
procedure final
rule publication.
Senneca Holdings................. PTO for Door Motors 2020-002 Appendix A......... 180 days after test
procedure final
rule publication.
Hercules......................... PTO for Door Motors 2020-013 Appendix A......... 180 days after test
procedure final
rule publication.
[[Page 23977]]
HTPG............................. CO2 Unit Coolers... 2020-009 Appendix C......... 180 days after test
procedure final
rule publication.
Hussmann......................... CO2 Unit Coolers... 2020-010 Appendix C......... 180 days after test
procedure final
rule publication.
Keeprite......................... CO2 Unit Coolers... 2020-014 Appendix C......... 180 days after test
procedure final
rule publication.
RefPlus, Inc..................... CO2 Unit Coolers... 2021-006 Appendix C......... 180 days after test
procedure final
rule publication.
RSG.............................. Multi-Circuit 2022-004 Appendix C......... 180 days after test
Single-Package procedure final
Dedicated Systems. rule publication.
Store It Cold.................... Single-Package 2018-002 Appendix C1........ Compliance date of
Dedicated Systems. updated standards.
CellarPro........................ Wine Cellar 2019-009 Appendix C1........ Compliance date of
Refrigeration updated standards.
Systems.
Air Innovations.................. Wine Cellar 2019-010 Appendix C1........ Compliance date of
Refrigeration updated standards.
Systems.
Vinotheque....................... Wine Cellar 2019-011 Appendix C1........ Compliance date of
Refrigeration updated standards.
Systems.
Vinotemp......................... Wine Cellar 2020-005 Appendix C1........ Compliance date of
Refrigeration updated standards.
Systems.
LRC Coil......................... Wine Cellar 2020-024 Appendix C1........ Compliance date of
Refrigeration updated standards.
Systems.
----------------------------------------------------------------------------------------------------------------
L. Organizational Changes
DOE is also proposing a number of non-substantive organizational
changes. As discussed previously, DOE is proposing to reorganize
appendices A and B so that they are easier for stakeholders to follow
as a step-by-step test procedure. Additionally, DOE is proposing to
remove the specifications at 10 CFR 429.53(a)(2)(i) regarding specific
test procedure provisions and instead include these provisions in the
uniform test method section at 10 CFR 431.304. The intent of this
proposed change is to move provisions of the applicable test procedure
to the appropriate place in subpart R, rather than keeping them under
the provisions for determining represented values for certification.
However, DOE is proposing to keep the additional detail regarding the
represented values of various configurations of refrigeration systems
(e.g., outdoor and indoor dedicated condensing units, matched
refrigeration systems, etc.) at 10 CFR 429.53(a)(2)(i).
IV. Procedural Issues and Regulatory Review
A. Review Under Executive Order 12866 and 13563
Executive Order (``E.O.'') 12866, ``Regulatory Planning and
Review,'' as supplemented and reaffirmed by E.O. 13563, ``Improving
Regulation and Regulatory Review,'' 76 FR 3821 (Jan. 21, 2011),
requires agencies, to the extent permitted by law, to (1) propose or
adopt a regulation only upon a reasoned determination that its benefits
justify its costs (recognizing that some benefits and costs are
difficult to quantify); (2) tailor regulations to impose the least
burden on society, consistent with obtaining regulatory objectives,
taking into account, among other things, and to the extent practicable,
the costs of cumulative regulations; (3) select, in choosing among
alternative regulatory approaches, those approaches that maximize net
benefits (including potential economic, environmental, public health
and safety, and other advantages; distributive impacts; and equity);
(4) to the extent feasible, specify performance objectives, rather than
specifying the behavior or manner of compliance that regulated entities
must adopt; and (5) identify and assess available alternatives to
direct regulation, including providing economic incentives to encourage
the desired behavior, such as user fees or marketable permits, or
providing information upon which choices can be made by the public. DOE
emphasizes as well that E.O. 13563 requires agencies to use the best
available techniques to quantify anticipated present and future
benefits and costs as accurately as possible. In its guidance, the
Office of Information and Regulatory Affairs (``OIRA'') has emphasized
that such techniques may include identifying changing future compliance
costs that might result from technological innovation or anticipated
behavioral changes. For the reasons stated in the preamble, this
proposed regulatory action is consistent with these principles.
Section 6(a) of E.O. 12866 also requires agencies to submit
``significant regulatory actions'' to OIRA for review. OIRA has
determined that this proposed regulatory action does not constitute a
``significant regulatory action'' under section 3(f) of E.O. 12866.
Accordingly, this action was not submitted to OIRA for review under
E.O. 12866.
B. Review Under the Regulatory Flexibility Act
The Regulatory Flexibility Act (5 U.S.C. 601 et seq.) requires
preparation of an initial regulatory flexibility analysis (``IRFA'')
for any rule that by law must be proposed for public comment, unless
the agency certifies that the rule, if promulgated, will not have a
significant economic impact on a substantial number of small entities.
As required by Executive Order 13272, ``Proper Consideration of Small
Entities in Agency Rulemaking,'' 67 FR 53461 (Aug. 16, 2002), DOE
published procedures and policies on February 19, 2003, to ensure that
the potential impacts of its rules on small entities are properly
considered during the DOE rulemaking process. 68 FR 7990. DOE has made
its procedures and policies available on the Office of the General
Counsel's website: www.energy.gov/gc/office-general-counsel.
The following sections detail DOE's IRFA for this test procedure
proposed rulemaking.
[[Page 23978]]
1. Description of Why Action Is Being Considered
The Energy Policy and Conservation Act, as amended (``EPCA''),\72\
authorizes DOE to regulate the energy efficiency of a number of
consumer products and certain industrial equipment. (42 U.S.C. 6291-
6317) Title III, Part C \73\ of EPCA, added by Public Law 95-619, Title
IV, section 441(a), established the Energy Conservation Program for
Certain Industrial Equipment, which sets forth a variety of provisions
designed to improve energy efficiency. This covered equipment includes
walk-in coolers and walk-in freezers, the subject of this document. (42
U.S.C. 6311(1)(G)) DOE is publishing this NOPR in satisfaction of the
7-year review requirement specified in EPCA. (42 U.S.C. 6314(a)(1))
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\72\ All references to EPCA in this document refer to the
statute as amended through the Energy Act of 2020, Public Law 116-
260 (Dec. 27, 2020).
\73\ For editorial reasons, upon codification in the U.S. Code,
Part C was redesignated Part A-1.
---------------------------------------------------------------------------
2. Objective of, and Legal Basis for, Rule
The Energy Policy and Conservation Act, as amended (``EPCA''),\74\
authorizes DOE to regulate the energy efficiency of a number of
consumer products and certain industrial equipment. (42 U.S.C. 6291-
6317) Title III, Part C \75\ of EPCA, added by Public Law 95-619, Title
IV, section 441(a), established the Energy Conservation Program for
Certain Industrial Equipment, which sets forth a variety of provisions
designed to improve energy efficiency. This covered equipment includes
walk-in coolers and walk-in freezers, the subject of this document. (42
U.S.C. 6311(1)(G))
---------------------------------------------------------------------------
\74\ All references to EPCA in this document refer to the
statute as amended through the Energy Act of 2020, Public Law 116-
260 (Dec. 27, 2020).
\75\ For editorial reasons, upon codification in the U.S. Code,
Part C was redesignated Part A-1.
---------------------------------------------------------------------------
Under 42 U.S.C. 6314, EPCA sets forth the criteria and procedures
DOE must follow when prescribing or amending test procedures for
covered equipment. EPCA requires that any test procedures prescribed or
amended under this section must be reasonably designed to produce test
results which reflect energy efficiency, energy use or estimated annual
operating cost of a given type of covered equipment during a
representative average use cycle and requires that test procedures not
be unduly burdensome to conduct. (42 U.S.C. 6314(a)(2))
EPCA also requires that, at least once every 7 years, DOE evaluate
test procedures for each type of covered equipment including WICFs, to
determine whether amended test procedures would more accurately or
fully comply with the requirements for the test procedures to not be
unduly burdensome to conduct and be reasonably designed to produce test
results that reflect energy efficiency, energy use, and estimated
operating costs during a representative average use cycle. (42 U.S.C.
614(a)(1)(A))
3. Description and Estimate of Small Entities Regulated
For manufacturers of WICFs, the Small Business Administration
(``SBA'') has set a size threshold, which defines those entities
classified as ``small businesses'' for the purposes of the statute. DOE
used the SBA's small business size standards to determine whether any
small entities would be subject to the requirements of the rule. See 13
CFR part 121. The equipment covered by this rule are classified under
North American Industry Classification System (``NAICS'') code
333415,\76\ ``Air-Conditioning and Warm Air Heating Equipment and
Commercial and Industrial Refrigeration Equipment Manufacturing.'' In
13 CFR 121.201, the SBA sets a threshold of 1,250 employees or fewer
for an entity to be considered as a small business for this category.
---------------------------------------------------------------------------
\76\ The size standards are listed by NAICS code and industry
description and are available at: www.sba.gov/document/support--table-size-standards (Last accessed on November 1, 2021).
---------------------------------------------------------------------------
DOE reviewed the test procedures proposed in this NOPR under the
provisions of the Regulatory Flexibility Act and the procedures and
policies published on February 19, 2003. DOE used publicly available
information to identify potential small businesses that manufacture
WICFs covered in this rulemaking. DOE's analysis relied on publicly
available databases to identify potential small businesses that
manufacture equipment covered in this rulemaking. DOE utilized the
DOE's Certification Compliance Database (``CCD'') \77\ and the
California Energy Commission's Modernized Appliance Efficiency Database
System (``MAEDbS'') \78\ in identifying manufacturers. DOE also used
subscription-based business information tools to determine headcount
and revenue of the small businesses.
---------------------------------------------------------------------------
\77\ Certified equipment in the CCD are listed by product class
and can be accessed at www.regulations.doe.gov/certification-data/#q=Product_Group_s%3A* (Last accessed July 15th, 2021).
\78\ MAEDbS can be accessed at
www.cacertappliances.energy.ca.gov/Pages/Search/AdvancedSearch.aspx
(Last accessed Nov. 1, 2021).
---------------------------------------------------------------------------
Using these data sources, DOE identified 79 original equipment
manufacturers (``OEMs'') of WICFs that could be potentially affected by
this rulemaking. DOE screened out companies that do not meet the
definition of a ``small business'' or are foreign-owned and operated.
Of these 79 OEMs, 60 are small, domestic manufacturers. DOE notes that
some manufacturers may produce more than one of the principal
components of WICFs: Panels, doors, and refrigeration systems. Eighteen
of the small, domestic OEMs manufacture refrigeration systems; 38 of
the small, domestic OEMs manufacture panels; and 43 of the small,
domestic OEMs manufacture doors. To better reflect the impact on
manufacturers, DOE evaluated the impacts of test procedure changes to
panels, doors, and refrigeration systems separately.
Of these small businesses, not all were impacted by the proposed
changes. The following section further details the impact to
manufacturers by principal component and proposed test procedure
amendment.
Issue 38: DOE invites comment on the number of small, domestic OEMs
producing the three principal components of WICFs: Panels, doors, and
refrigeration systems.
4. Description and Estimate of Compliance Requirements
The potential regulatory costs of the proposed test procedure are
differentiated by WICF component: Panels, doors, and refrigeration
systems. The following sub-sections outline these changes and potential
burden.
a. Doors
In this NOPR, DOE proposes the following amendments to the test
procedures for walk-in cooler and freezer doors:
1. Referencing NFRC 102-2020 for the determination of U-factor;
2. Including AEDM \79\ provisions for manufacturers to alternately
determine the total energy consumption of display and non-display
doors;
---------------------------------------------------------------------------
\79\ An AEDM is a computer modeling or mathematical tool that
predicts the performance of non-tested basic models. These computer
modeling and mathematical tools, when properly developed, can
provide a means to predict the energy usage or efficiency
characteristics of a basic model of a given covered product or
equipment and reduce the burden and cost associated with testing.
---------------------------------------------------------------------------
3. Providing additional detail for determining the area used to
convert U-factor into conduction load, As, to differentiate it from the
area used to determine compliance with the standards, Add or And; and
4. Specifying a percent time off (``PTO'') value of 97 percent for
door motors.
Items 1 and 3, referencing NFRC 102-2020 and additional detail on
the area used to convert U-factor into a
[[Page 23979]]
conduction load, would improve the consistency, reproducibility, and
representativeness of test procedure results. Item 2, including AEDM
provisions, would provide manufacturers with the flexibility to use an
alternative method that gives the best agreement for their doors. Item
4, specifying a PTO value of 97 percent for door motors, would provide
a more representative and consistent means for comparison of walk-in
door performance for doors with motors. DOE has tentatively determined
that these proposed amendments as a whole would improve the
representativeness, accuracy, and reproducibility of the test results,
and would not be unduly burdensome for door manufacturers to conduct.
DOE has also tentatively determined that these proposed amendments
would not increase physical testing costs per basic model relative to
the current DOE test procedure in appendix A, which DOE estimates to be
$10,000 for third-party labs to determine energy consumption of a walk-
in door, including physical U-factor testing per NFRC 102-2020.\80\ DOE
has tentatively determined that manufacturers would not be required
redesign any of the covered equipment or change how the equipment is
manufactured, solely as result of the proposed amendments.
---------------------------------------------------------------------------
\80\ DOE estimates the cost of one test to determine energy
consumption of a walk-in door, including one physical U-factor test
per NFRC 102-2020, to be $5,000. Per the sampling requirements
specified at 10 CFR 429.53(a)(3)(ii) and 10 CFR 429.11(b),
manufacturers are required to test at least two units to determine
the rating for a basic model, except where only one unit of the
basic model is produced.
---------------------------------------------------------------------------
DOE is also proposing to permit manufacturers to use AEDMs. Using
AEDMs when evaluating the energy efficiency of their equipment may
enable some manufacturers to reduce costs to rate models. AEDMs can
require an upfront investment but lower overall testing costs. The cost
impact to manufacturers as result of the reference to NFRC 102-2020 and
inclusion of AEDM provisions is dependent on the agreement specified in
Section 4.7.1 of NFRC 100 \81\ between U-factors simulated using the
method in NFRC 100 and U-factors tested using NFRC 102. For
manufacturers of doors that have been able to achieve the specified
agreement between U-factors simulated using the method in NFRC 100 and
U-factors tested using NFRC 102, manufacturers would be able to
continue using the simulation method in NFRC 100, provided that the
simulation method also meets the basic requirements proposed for an
AEDM in 10 CFR 429.53 and 10 CFR 429.70(f).
---------------------------------------------------------------------------
\81\ Section 4.7.1 of NFRC 100 requires that the accepted
difference between the tested U-factor and the simulated U-factor be
(a) 0.03 Btu/(h-ft\2\-[deg]F) for simulated U-factors that are 0.3
Btu/(h-ft\2\-[deg]F) or less, or 10 percent of the simulated U-
factor for simulated U-factors greater than 0.3 Btu/(h-ft\2\-
[deg]F). This agreement must match for the baseline product in a
product line. Per NFRC 100, the baseline product is the individual
product selected for validation; it is not synonymous with ``basic
model'' as defined in 10 CFR 431.302.
---------------------------------------------------------------------------
For manufacturers of doors that have not been able to achieve the
specified agreement between U-factors simulated using the method in
NFRC 100 and U-factors tested using NFRC 102, DOE estimates that the
test burden could decrease. Under the current requirements,
manufacturers may be required to physically test every model to meet
the basic model definition since these models are highly customizable.
If the proposed test procedure is adopted, manufacturers who would
otherwise physically test every walk-in door basic model could develop
an AEDM for rating. DOE estimates the per-manufacturer cost to develop
and validate an AEDM for a single validation class of walk-in doors to
be $11,100. DOE estimates the cost to determine energy consumption of a
walk-in door using an AEDM to be $46 per basic model.
DOE expects that the additional detail provided for determining the
area used to convert U-factor into conduction load, As, would either
result in a reduced energy consumption or have no impact. To the extent
that this change to the test procedure would amend the energy
consumption attributable to a door, such changes would either not
change the calculated energy consumption or result in a lower energy
consumption value as compared to how manufacturers may currently be
rating. As such, DOE expects that manufacturers would be able to rely
on data generated under the current test procedure. While manufacturers
must submit a report annually to certify a basic model's represented
values, basic models do not need to be retested annually. The initial
test results used to generate a certified rating for a basic model
remain valid as long as the basic model has not been modified from the
tested design in a way that makes it less efficient or more
consumptive, which would require a change to the certified rating. If a
manufacturer has modified a basic model in a way that makes it more
efficient or less consumptive, new testing is only required if the
manufacturer wishes to make claims of the new, more efficient
rating.\82\
---------------------------------------------------------------------------
\82\ See guidance issued by DOE at: www1.eere.energy.gov/buildings/appliance_standards/pdfs/cert_faq_2012-04-17.pdf.
---------------------------------------------------------------------------
For doors without motors, DOE has tentatively concluded that the
proposed test procedure would not change energy consumption ratings,
and therefore would not require re-rating as a result this proposed
test procedure. Therefore, DOE has determined the proposed amendments
would either decrease or result in no additional testing costs to small
business manufacturers of walk-in doors.
To the extent that changes to the test procedure would amend the
energy consumption attributable to a door motor, such changes would
either not change the calculated energy consumption or result in a
lower energy consumption value as compared to the currently granted
waivers addressing door motors. As such, DOE expects that manufacturers
would be able to rely on data generated under the current test
procedure and current waivers. While manufacturers must submit a report
annually to certify a basic model's represented values, basic models
would not need to be retested annually. The initial test results used
to generate a certified rating for a basic model would remain valid as
long as the basic model has not been modified from the tested design in
a way that makes it less efficient or more consumptive, which would
require a change to the certified rating. If a manufacturer has
modified a basic model in a way that makes it more efficient or less
consumptive, new testing would be required only if the manufacturer
wishes to make claims of the new, more efficient rating.\83\
---------------------------------------------------------------------------
\83\ See guidance issued by DOE at: www1.eere.energy.gov/buildings/appliance_standards/pdfs/cert_faq_2012-04-17.pdf.
---------------------------------------------------------------------------
Issue 39: DOE requests comment on its cost estimate of impacts on
small, domestic OEMs of doors.
b. Panels
DOE proposes to amend the existing test procedure in appendix B for
measuring the R-value of insulation of walk-in panels by:
1. Incorporating by reference the updated version of the applicable
industry test method, ASTM C518-17;
2. Including provisions specific to the measurement of test
specimen and total insulation thickness; and
3. Providing guidance on determining the parallelism and flatness
of the test specimen.
Item 1 incorporates by reference the most up to date version of the
industry standards currently referenced in the DOE test procedure.
Items 2 and 3 includes additional instructions that would improve the
consistency and reproducibility of test procedure results.
[[Page 23980]]
DOE has tentatively determined that these proposed amendments would
improve the accuracy and reproducibility of the test results and would
not be unduly burdensome for manufacturers to conduct, nor would they
be expected to increase the testing burden.
DOE expects that the proposed test procedure in appendix B for the
measuring R-value of insulation would not increase testing costs per
basic model relative to the current DOE test procedure, which DOE
estimates to be $1,200 for third-party lab testing.\84\ Additionally,
DOE has tentatively determined that manufacturers would not be required
to redesign any of the covered equipment or change how the equipment is
manufactured, solely as result of the proposed amendments. Further, DOE
has tentatively determined that the proposed amendments would not
impact the utility of the equipment.
---------------------------------------------------------------------------
\84\ DOE estimates the cost of one test to determine R-value to
be $600. Per the sampling requirements specified at 10 CFR
429.53(a)(3)(ii) and 10 CFR 429.11(b), manufacturers are required to
test at least two units to determine the rating for a basic model,
except where only one unit of the basic model is produced.
---------------------------------------------------------------------------
DOE has tentatively concluded that the proposed test procedure
would not change efficiency ratings for walk-in panels, and therefore
would not require re-rating as result of DOE's adoption of this
proposed amendment to the test procedure. Therefore, DOE has determined
the proposed amendments would not add any additional testing costs to
small business manufacturers of walk-in doors.
Issue 40: DOE requests comment on its cost estimate of impacts on
small, domestic OEMs of panels.
c. Refrigeration Systems
In this NOPR, DOE proposes certain changes to subpart R, appendix
C, that DOE has tentatively determined would improve the accuracy and
reproducibility of the test results and would not be unduly burdensome
for manufacturers to conduct. DOE has tentatively determined that these
proposed changes would not impact testing cost. Additionally, the
proposed amended subpart R, appendix C, measuring AWEF per AHRI 1250-
2009, does not contain any changes that would require retesting or
rerating if it were to be adopted.
DOE also proposes to adopt through incorporations by reference
certain provisions of AHRI 1250-2020 in appendix C1 that would amend
the existing test procedure for walk-in cooler and freezer
refrigeration systems. Additionally, DOE proposes amendments to the
current DOE test procedure to accommodate high-temperature
refrigeration systems and CO2 unit coolers. A summary of the
proposed changes are as follows:
1. Expanding the off-cycle refrigeration system power measurements;
2. Adding air enthalpy methods for single-packaged dedicated
systems;
3. Including new test procedures for high-temperature refrigeration
systems; and
4. Including new test procedures for CO2 unit coolers.
DOE has tentatively determined that these proposed amendments would
improve the representativeness, accuracy, and reproducibility of the
test results, and would not be unduly burdensome for manufacturers to
conduct. DOE has also tentatively determined that these proposed
amendments may impact testing costs. The following paragraphs outline
the proposed changes and the potential costs to manufacturers. Because
DOE's proposal of off-cycle refrigeration power measurements and
single-packaged dedicated system air enthalpy test methods requirements
impact both high-temperature and CO2 units, all potential
cost impacts to high-temperature and CO2 units are discussed
separately in the third and fourth sections.
(1) Small Business Impacts as a Result of Off-Cycle Refrigeration
System Power Requirements
DOE is proposing to adopt the off-cycle testing for walk-ins in
AHRI 1250-2020. The current test procedure requires off-cycle power to
be measured at the 95 [deg]F ambient condition. The proposed test
procedure requires off-cycle to be measured at 95 [deg]F, 59 [deg]F,
and 35 [deg]F ambient conditions for outdoor dedicated condensing
units, outdoor matched pair systems, and outdoor single-packaged
dedicated systems. These proposed amendments would not increase testing
costs or require manufacturers to re-rate models, as DOE energy
conservation standards do not currently require off-cycle requirements
to be measured at 95 [deg]F, 59 [deg]F, and 35 [deg]F ambient
conditions for outdoor dedicated condensing units, outdoor matched pair
systems, and outdoor single-packaged systems. However, should DOE adopt
energy conservation standards that require these off-cycle
requirements, DOE estimates that measuring off-cycle power at these
additional ambient conditions may increase per-unit third-party lab
test cost by $1,000 per unit to a total cost of $11,000 per unit for
outdoor dedicated condensing units and outdoor matched pair
systems.\85\ The physical testing cost, according to the proposed
amendments, would be $22,000 per basic model for outdoor dedicated
condensing units and outdoor matched pair systems.\86\
---------------------------------------------------------------------------
\85\ Outdoor single-packaged systems are also impacted by the
proposed adoption of AHRI 1250-2020 single-packaged test procedure
for walk-in cooler and freezer refrigeration systems. The combined
potential cost increase for outdoor single-packaged systems is
presented in the following section.
\86\ The cost to test one unit is $11,000. Per the sampling
requirements specified at 10 CFR 429.53(a)(2)(ii) and 10 CFR
429.11(b), manufacturers are required to test at least two units to
determine the rating for a basic model, except where only one unit
of the basic model is produced.
---------------------------------------------------------------------------
However, manufacturers are not required to perform laboratory
testing on all basic models. In accordance with 10 CFR 429.53, WICF
refrigeration system manufacturers may elect to use AEDMs. DOE
estimates the per-manufacturer cost to develop and validate an AEDM for
outdoor dedicated condensing units and outdoor matched pair systems to
be $24,580 per validation class. DOE estimates an additional cost of
approximately $46 per basic model \87\ for determining energy
efficiency using the validated AEDM.
---------------------------------------------------------------------------
\87\ DOE estimated initial costs to validate an AEDM assuming 40
hours of general time to develop an AEDM based on existing
simulation tools and 16 hours to validate two basic models within
that AEDM at the cost of an engineering calibration technician fully
burdened wage of $46 per hour plus the cost of third-party physical
testing of two units per validation class (as required in 10 CFR
429.70(c)(2)(iv)). DOE estimated the additional per basic model cost
to determine efficiency using an AEDM assuming 1 hour per basic
model at the cost of an engineering calibration technician wage of
$46 per hour.
---------------------------------------------------------------------------
DOE estimates the range of potential costs for the five small OEMs
that manufacture outdoor dedicated condensing units and outdoor matched
pair systems. When developing cost estimates for the small OEMs, DOE
considers the cost to update the existing AEDM simulation tool, the
costs to validate the AEDM through physical testing, and the cost to
rate basic models using the AEDM. DOE assumes a high-cost scenario
where manufacturers would be required to develop AEDMs for six
validation classes.
DOE estimates the impacts based on basic model counts and company
revenue. Table IV.1 summarizes DOE's estimates for the five identified
small businesses. On average, testing costs represent less than 1
percent of annual revenue for a typical small business.
[[Page 23981]]
Table IV.1--Estimated Small Business Re-Rating Costs (2022$) as a Result of Off-Cycle Refrigeration System Power
Requirements
----------------------------------------------------------------------------------------------------------------
Re-rating Annual revenue Percent of
Manufacturer estimate ($mm) estimate ($mm) revenue (%)
----------------------------------------------------------------------------------------------------------------
Manufacturer A.................................................. 0.151 12 1.25
Manufacturer B.................................................. 0.148 19 0.78
Manufacturer C.................................................. 0.214 77 0.28
Manufacturer D.................................................. 0.148 86 0.17
Manufacturer E.................................................. 0.159 147 0.10
----------------------------------------------------------------------------------------------------------------
(2) Small Business Impacts as a Result of Requiring Single-Packaged
Dedicated Systems To Test Using Air Enthalpy Methods
DOE is also proposing to adopt the single-packaged dedicated system
test procedure in AHRI 1250-2020 for walk-in cooler and freezer
refrigeration systems. The proposed procedure requires air enthalpy
tests to be used as the primary test method. In the current test
procedure, single-packaged dedicated systems use refrigerant enthalpy
as the primary test method. DOE estimates no difference in costs
between air and refrigerant enthalpy testing of single-packaged
dedicated systems. DOE estimates the per-unit third-party lab test cost
to be $11,000 for outdoor single-packaged dedicated systems and $6,500
for indoor single-packaged dedicated systems. The physical testing
cost, according to the proposed amendments, would be $22,000 per basic
model for outdoor single-packaged dedicated systems and $13,000 per
basic model for indoor package systems.\88\ However, manufacturers of
single-packaged dedicated systems may elect to use AEDMs. DOE estimates
the per-manufacturer cost to develop and validate an AEDM per
validation class to be $24,580 for outdoor single-packaged dedicated
systems and $15,580 for indoor single-packaged dedicated systems. DOE
estimates an additional cost of approximately $46 per basic model \89\
for determining energy efficiency using the validated AEDM.
---------------------------------------------------------------------------
\88\ Per the sampling requirements specified at 10 CFR
429.53(a)(2)(ii) and 10 CFR 429.11(b), manufacturers are required to
test at least two units to determine the rating for a basic model,
except where only one unit of the basic model is produced.
\89\ DOE estimated initial costs to validate an AEDM assuming 40
hours of general time to develop an AEDM based on existing
simulation tools and 16 hours to validate two basic models within
that AEDM at the cost of an engineering calibration technician fully
burdened wage of $46 per hour plus the cost of third-party physical
testing of two units per validation class (as required in 10 CFR
429.70(c)(2)(iv)). DOE estimated the additional per basic model cost
to determine efficiency using an AEDM assuming 1 hour per basic
model at the cost of an engineering calibration technician wage of
$46 per hour.
---------------------------------------------------------------------------
DOE estimated the range of potential costs for the two domestic,
small OEMs that manufacture single-packaged dedicated systems. When
developing cost estimates for the small OEMs, DOE considered the cost
to update the existing AEDM simulation tool, the costs to validate the
AEDM through physical testing, and the cost to rate basic models using
the AEDM.
Both small businesses manufacture indoor and outdoor, low and
medium temperature, single-packaged dedicated systems. One small
business manufactures 28 basic models of single-packaged dedicated
systems with an estimated annual revenue of $19 million. Therefore, DOE
estimates that the associated re-rating costs for this manufacturer to
be approximately $81,650 when making use of AEDMs. The cost for this
manufacturer represents less than 1 percent of annual revenue.
The second small business manufactures 38 basic models of single-
packaged dedicated systems with an estimated annual revenue of $147
million. Therefore, DOE estimates that the associated re-rating costs
for this manufacturer to be approximately $82,100 when making use of
AEDMs. The cost for this manufacturer represents less than 1 percent of
annual revenue.
(3) Small Business Impacts as a Result of New Test Procedures for High-
Temperature Refrigeration Systems
DOE is proposing test procedures for high-temperature refrigeration
systems. DOE has granted waivers to certain manufacturers for high-
temperature refrigeration systems. The test procedures proposed in this
NOPR are consistent with the alternate test procedures included in the
granted waivers, excluding the changes discussed previously about off-
cycle power measurements. For those manufacturers who have been granted
a test procedure waiver for this equipment, DOE expects the only test
burden incurred would be that related to off-cycle requirements.
However, DOE expects that there would be additional testing costs for
any manufacturers of these products who have not submitted or been
granted a test procedure waiver at the time this proposed test
procedure is finalized.
For manufacturers that have been granted waivers, DOE estimates
that measuring off-cycle power at these additional ambient conditions
may increase per-unit third-party lab test cost by $1,000 to a total
per-unit cost of $11,000 for high-temperature outdoor dedicated
condensing units, outdoor matched pair systems, and outdoor single-
packaged dedicated systems. The physical testing cost, according to the
proposed amendments, would be $22,000 per basic model for outdoor
dedicated condensing units and outdoor matched pair systems.\90\
---------------------------------------------------------------------------
\90\ Per the sampling requirements specified at 10 CFR
429.53(a)(2)(ii) and 10 CFR 429.11(b), manufacturers are required to
test at least two units to determine the rating for a basic model,
except where only one unit of the basic model is produced.
---------------------------------------------------------------------------
However, manufacturers are not required to perform laboratory
testing on all basic models. In accordance with 10 CFR 429.53, WICF
refrigeration system manufacturers may elect to use AEDMs. DOE
estimates the per-manufacturer cost to develop and validate an AEDM for
outdoor dedicated condensing units and outdoor matched pair systems to
be $24,580 per validation class. DOE estimates an additional cost of
approximately $46 per basic model \91\ for determining energy
efficiency using the validated AEDM.
---------------------------------------------------------------------------
\91\ DOE estimated initial costs to validate an AEDM assuming 40
hours of general time to develop an AEDM based on existing
simulation tools and 16 hours to validate two basic models within
that AEDM at the cost of an engineering calibration technician fully
burdened wage of $46 per hour plus the cost of third-party physical
testing of two units per validation class (as required in 10 CFR
429.70(c)(2)(iv)). DOE estimated the additional per basic model cost
to determine efficiency using an AEDM assuming 1 hour per basic
model at the cost of an engineering calibration technician wage of
$46 per hour.
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[[Page 23982]]
DOE estimated the potential costs to manufacturers of high-
temperature units as a result of off-cycle requirements using an AEDM.
Specifically, DOE estimated the range of potential costs for the five
identified domestic, small OEMs that manufacture high-temperature
units. When developing cost estimates for the small OEMs, DOE considers
the cost to develop the AEDM simulation tool, the costs to validate the
AEDM through physical testing, and the cost to rate basic models using
the AEDM. DOE assumes a scenario where manufacturers would be required
to develop AEDMs for three validation classes.
DOE estimated the impacts based on basic model counts and company
revenue. Table IV.2 summarizes DOE's estimates for the five identified
small businesses. On average, testing costs represent approximately 1.5
percent of annual revenue for a typical small business.
Table IV.2--Estimated Small Business Re-Rating Costs (2022$) for High-Temperature Refrigeration Systems
----------------------------------------------------------------------------------------------------------------
Re-rating Annual revenue Percent of
Manufacturer estimate ($mm) estimate ($mm) revenue (%)
----------------------------------------------------------------------------------------------------------------
Manufacturer A.................................................. 0.075 2.1 3.57
Manufacturer B.................................................. 0.074 3.6 2.06
Manufacturer C.................................................. 0.074 8.9 0.84
Manufacturer D.................................................. 0.076 11 0.70
Manufacturer E.................................................. 0.075 14 0.53
----------------------------------------------------------------------------------------------------------------
For manufacturers that have not been granted waivers, manufacturers
of high-temperature equipment may incur first-time rating expenses. DOE
estimates these manufacturers may incur rating expenses up to $22,000
per basic model for a high-temperature matched pair, $22,000 per basic
model for a single-packaged dedicated system, and $12,000 per basic
model for a high-temperature unit cooler.\92\
---------------------------------------------------------------------------
\92\ Per the sampling requirements specified at 10 CFR
429.53(a)(2)(ii) and 10 CFR 429.11(b), manufacturers are required to
test at least two units to determine the rating for a basic model,
except where only one unit of the basic model is produced.
---------------------------------------------------------------------------
(4) Small Business Impacts as a Result of New Test Procedures for
CO2 Unit Coolers
Lastly, DOE is proposing test procedures for CO2 unit
coolers. DOE has granted waivers to certain manufacturers for
CO2 unit coolers. In this proposal, DOE is proposing that
CO2 refrigeration systems, as DOE proposed to define in
section III.A.2.h of this NOPR, meet the definition of a walk-in, but
that the DOE test procedure is applicable only to single-packaged
dedicated and to unit cooler variants of CO2 refrigeration
systems. All CO2 refrigerant waiver petitions DOE has thus
far received address unit coolers. 86 FR 32332, 32346.
The test procedures proposed in this NOPR are consistent with the
alternate test procedures included in the granted waivers. For those
manufacturers who have been granted a test procedure waiver for this
equipment, DOE expects no change in test burden. However, DOE expects
that there would be additional testing costs for any manufacturers of
these products who have not submitted or been granted a test procedure
waiver at the time this proposed test procedure is finalized. This
additional cost is partially offset because, without a method of test,
manufacturers of these products would not be able to sell them in the
U.S. since there would be no way of certifying their energy use as
required EPCA.
For manufacturers that have not been granted waivers, manufacturers
of CO2 equipment may incur first-time rating expenses. DOE
estimates these manufacturers may incur rating expenses up to $13,000
per-unit for a low temperature CO2 unit cooler and $12,000
per-unit for a medium temperature CO2 unit cooler.\93\
However, manufacturers of CO2 unit coolers may choose to
utilize an AEDM. Furthermore, AEDM unit cooler validation classes do
not distinguish between CO2 unit coolers and non-
CO2 unit coolers. Therefore, manufacturers of CO2
unit coolers may use the same validation classes as non-CO2
unit coolers.
---------------------------------------------------------------------------
\93\ Per the sampling requirements specified at 10 CFR
429.53(a)(2)(ii) and 10 CFR 429.11(b), manufacturers are required to
test at least two units to determine the rating for a basic model,
except where only one unit of the basic model is produced.
---------------------------------------------------------------------------
Issue 41: DOE requests comment on its cost estimate of impacts on
small, domestic OEMs of refrigeration systems.
5. Duplication, Overlap, and Conflict With Other Rules and Regulations
DOE is not aware of any rules or regulations that duplicate,
overlap, or conflict with the rule being considered in this document.
6. Significant Alternatives to the Rule
DOE proposes to reduce burden on manufacturers, including small
businesses, by allowing AEDMs in lieu of physically testing all basic
models. The use of an AEDM is less costly than physical testing WICF
components. For doors, DOE's proposed inclusion of AEDM provisions
would allow manufacturers to develop an AEDM for rating their models.
Without an AEDM, DOE estimates physical testing would cost door
manufacturers $10,000 per basic model. With the use of an AEDM, DOE
estimates the costs of $11,100 to develop and validate a single
validation class plus an additional $46 per basic model yielding
savings to manufacturers that produce more than one basic model of
door. For refrigeration systems, DOE estimates $24,580 at the high-end
of the range to develop and validate an AEDM with an additional cost of
$46 per basic model. With a high-end cost of approximately $22,000 per
basic model to physically test refrigeration models, manufacturers of
three or more basic models could yield cost savings.
Additional compliance flexibilities may be available through other
means. For example, manufacturers subject to DOE's energy efficiency
standards may apply to DOE's Office of Hearings and Appeals for
exception relief under certain circumstances. Manufacturers should
refer to 10 CFR part 1003 for additional details.
C. Review Under the Paperwork Reduction Act of 1995
Manufacturers of walk-ins must certify to DOE that their products
comply with any applicable energy conservation standards. To certify
[[Page 23983]]
compliance, manufacturers must first obtain test data for their
products according to the DOE test procedures, including any amendments
adopted for those test procedures. DOE has established regulations for
the certification and recordkeeping requirements for all covered
consumer products and commercial equipment, including walk-ins. See
generally 10 CFR part 429. The collection-of-information requirement
for the certification and recordkeeping is subject to review and
approval by the Office of Management and Budget (``OMB'') under the
Paperwork Reduction Act (``PRA''). This requirement has been approved
by OMB under OMB control number 1910-1400. Public reporting burden for
the certification is estimated to average 35 hours per response,
including the time for reviewing instructions, searching existing data
sources, gathering and maintaining the data needed, and completing and
reviewing the collection of information.
DOE is not proposing to amend the certification or reporting
requirements for walk-ins in this NOPR. Instead, DOE may consider
proposals to amend the certification requirements and reporting for
walk-ins under a separate rulemaking regarding appliance and equipment
certification. DOE will address changes to OMB Control Number 1910-1400
at that time, as necessary.
Notwithstanding any other provision of the law, no person is
required to respond to, nor shall any person be subject to a penalty
for failure to comply with, a collection of information subject to the
requirements of the PRA, unless that collection of information displays
a currently valid OMB Control Number.
D. Review Under the National Environmental Policy Act of 1969
In this NOPR, DOE proposes test procedure amendments that it
expects would be used to develop and implement future energy
conservation standards for walk-in coolers and freezers. DOE has
determined that this rule falls into a class of actions that are
categorically excluded from review under the National Environmental
Policy Act of 1969 (42 U.S.C. 4321 et seq.) and DOE's implementing
regulations at 10 CFR part 1021. Specifically, DOE has tentatively
determined that adopting test procedures for measuring energy
efficiency of consumer products and industrial equipment is consistent
with activities identified in 10 CFR part 1021, appendix A to subpart
D, A5 and A6. See also 10 CFR 1021.410. DOE will complete its NEPA
review before issuing the final rule.
E. Review Under Executive Order 13132
Executive Order 13132, ``Federalism,'' 64 FR 43255 (Aug. 4, 1999),
imposes certain requirements on agencies formulating and implementing
policies or regulations that preempt State law or that have federalism
implications. The Executive order requires agencies to examine the
constitutional and statutory authority supporting any action that would
limit the policymaking discretion of the States and to carefully assess
the necessity for such actions. The Executive order also requires
agencies to have an accountable process to ensure meaningful and timely
input by State and local officials in the development of regulatory
policies that have federalism implications. On March 14, 2000, DOE
published a statement of policy describing the intergovernmental
consultation process it will follow in the development of such
regulations. 65 FR 13735. DOE has examined this proposed rule and has
tentatively determined that it would not have a substantial direct
effect on the States, on the relationship between the National
Government and the States, or on the distribution of power and
responsibilities among the various levels of government. EPCA governs
and prescribes Federal preemption of State regulations as to energy
conservation for the products that are the subject of this proposed
rule. States can petition DOE for exemption from such preemption to the
extent, and based on criteria, set forth in EPCA. (42 U.S.C. 6297(d))
No further action is required by Executive Order 13132.
F. Review Under Executive Order 12988
Regarding the review of existing regulations and the promulgation
of new regulations, section 3(a) of Executive Order 12988, ``Civil
Justice Reform,'' 61 FR 4729 (Feb. 7, 1996), imposes on Federal
agencies the general duty to adhere to the following requirements: (1)
Eliminate drafting errors and ambiguity, (2) write regulations to
minimize litigation, (3) provide a clear legal standard for affected
conduct rather than a general standard, and (4) promote simplification
and burden reduction. Section 3(b) of Executive Order 12988
specifically requires that executive agencies make every reasonable
effort to ensure that the regulation (1) clearly specifies the
preemptive effect, if any, (2) clearly specifies any effect on existing
Federal law or regulation, (3) provides a clear legal standard for
affected conduct while promoting simplification and burden reduction,
(4) specifies the retroactive effect, if any, (5) adequately defines
key terms, and (6) addresses other important issues affecting clarity
and general draftsmanship under any guidelines issued by the Attorney
General. Section 3(c) of Executive Order 12988 requires executive
agencies to review regulations in light of applicable standards in
sections 3(a) and 3(b) to determine whether they are met, or it is
unreasonable to meet one or more of them. DOE has completed the
required review and determined that, to the extent permitted by law,
the proposed rule meets the relevant standards of Executive Order
12988.
G. Review Under the Unfunded Mandates Reform Act of 1995
Title II of the Unfunded Mandates Reform Act of 1995 (``UMRA'')
requires each Federal agency to assess the effects of Federal
regulatory actions on State, local, and Tribal governments, and the
private sector. Public Law 104-4, sec. 201 (codified at 2 U.S.C. 1531).
For a proposed regulatory action likely to result in a rule that may
cause the expenditure by State, local, and Tribal governments, in the
aggregate, or by the private sector of $100 million or more in any one
year (adjusted annually for inflation), section 202 of UMRA requires a
Federal agency to publish a written statement that estimates the
resulting costs, benefits, and other effects on the national economy.
(2 U.S.C. 1532(a), (b)) The UMRA also requires a Federal agency to
develop an effective process to permit timely input by elected officers
of State, local, and Tribal governments on a proposed ``significant
intergovernmental mandate,'' and requires an agency plan for giving
notice and opportunity for timely input to potentially affected small
governments before establishing any requirements that might
significantly or uniquely affect small governments. On March 18, 1997,
DOE published a statement of policy on its process for
intergovernmental consultation under UMRA. 62 FR 12820; also available
at energy.gov/gc/office-general-counsel. DOE examined this proposed
rule according to UMRA and its statement of policy and determined that
the rule contains neither an intergovernmental mandate, nor a mandate
that may result in the expenditure of $100 million or more in any year,
so these requirements do not apply.
H. Review Under the Treasury and General Government Appropriations Act,
1999
Section 654 of the Treasury and General Government Appropriations
[[Page 23984]]
Act, 1999 (Pub. L. 105-277), requires Federal agencies to issue a
Family Policymaking Assessment for any rule that may affect family
well-being. This proposed rule would not have any impact on the
autonomy or integrity of the family as an institution. Accordingly, DOE
has concluded that it is not necessary to prepare a Family Policymaking
Assessment.
I. Review Under Executive Order 12630
DOE has determined, under Executive Order 12630, ``Governmental
Actions and Interference with Constitutionally Protected Property
Rights,'' 53 FR 8859 (March 18, 1988), that this proposed regulation
would not result in any takings that might require compensation under
the Fifth Amendment to the U.S. Constitution.
J. Review Under Treasury and General Government Appropriations Act,
2001
Section 515 of the Treasury and General Government Appropriations
Act, 2001 (44 U.S.C. 3516 note), provides for agencies to review most
disseminations of information to the public under guidelines
established by each agency pursuant to general guidelines issued by
OMB. OMB's guidelines were published at 67 FR 8452 (Feb. 22, 2002), and
DOE's guidelines were published at 67 FR 62446 (Oct. 7, 2002). Pursuant
to OMB Memorandum M-19-15, Improving Implementation of the Information
Quality Act (April 24, 2019), DOE published updated guidelines which
are available at www.energy.gov/sites/prod/files/2019/12/f70/DOE%20Final%20Updated%20IQA%20Guidelines%20Dec%202019.pdf. DOE has
reviewed this proposed rule under the OMB and DOE guidelines and has
concluded that it is consistent with applicable policies in those
guidelines.
K. Review Under Executive Order 13211
Executive Order 13211, ``Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use,'' 66 FR 28355
(May 22, 2001), requires Federal agencies to prepare and submit to OMB,
a Statement of Energy Effects for any proposed significant energy
action. A ``significant energy action'' is defined as any action by an
agency that promulgated or is expected to lead to promulgation of a
final rule, and that (1) is a significant regulatory action under
Executive Order 12866, or any successor order; and (2) is likely to
have a significant adverse effect on the supply, distribution, or use
of energy; or (3) is designated by the Administrator of OIRA as a
significant energy action. For any proposed significant energy action,
the agency must give a detailed statement of any adverse effects on
energy supply, distribution, or use should the proposal be implemented,
and of reasonable alternatives to the action and their expected
benefits on energy supply, distribution, and use.
The proposed regulatory action to amend the test procedure for
measuring the energy efficiency of walk-ins is not a significant
regulatory action under Executive Order 12866. Moreover, it would not
have a significant adverse effect on the supply, distribution, or use
of energy, nor has it been designated as a significant energy action by
the Administrator of OIRA. Therefore, it is not a significant energy
action, and, accordingly, DOE has not prepared a Statement of Energy
Effects.
L. Review Under Section 32 of the Federal Energy Administration Act of
1974
Under section 301 of the Department of Energy Organization Act
(Pub. L. 95-91; 42 U.S.C. 7101), DOE must comply with section 32 of the
Federal Energy Administration Act of 1974, as amended by the Federal
Energy Administration Authorization Act of 1977. (15 U.S.C. 788;
``FEAA'') Section 32 essentially provides in relevant part that, where
a proposed rule authorizes or requires use of commercial standards, the
notice of proposed rulemaking must inform the public of the use and
background of such standards. In addition, section 32(c) requires DOE
to consult with the Attorney General and the Chairman of the Federal
Trade Commission (``FTC'') concerning the impact of the commercial or
industry standards on competition.
The proposed modifications to the test procedure for walk-ins would
incorporate testing methods contained in certain sections of the
following commercial standards: NFRC 102-2020, ASTM C1199-14, ASTM
C518-17, AHRI 1250-2020, ASHRAE 37-2009, AHRI 1250-2020, ANSI/ASHRAE
37-2009, and ANSI/ASHRAE 16-2016. DOE has evaluated these standards and
is unable to conclude whether they fully comply with the requirements
of section 32(b) of the FEAA (i.e., whether they were developed in a
manner that fully provides for public participation, comment, and
review). DOE will consult with both the Attorney General and the
Chairman of the FTC concerning the impact of these test procedures on
competition, prior to prescribing a final rule.
M. Description of Materials Incorporated by Reference
In this NOPR, DOE proposes to incorporate by reference the
following industry test standards into 10 CFR part 431:
(1) AHRI Standard 1250-2020, ``Standard for Performane Rating of
Walk-in Coolers and Freezers,'' copyright 2020.
AHRI 1250-2020 is an industry-accepted test procedure for measuring
the performance of walk-in cooler and walk-in freezer refrigeration
systems. AHRI 1250-2020 is available on AHRI's website at
www.ahrinet.org/search-standards.
(2) ANSI/ASHRAE Standard 16-2016, ``Method of Testing for Rating
Room Air Conditioners, Packaged Terminal Air Conditioners, and Packaged
Terminal Heat Pumps for Cooling and Heating Capacity,'' approved
October 31, 2016.
ANSI/ASHRAE 16 is an industry-accepted test procedure for measuring
cooling and heating capacity of room air conditioners, packaged
terminal air conditioners, and packaged terminal heat pumps referenced
by AHRI 1250-2020. ANSI/ASHRAE 16 includes test provisions related to
the measuring of the capacity of single-packaged dedicated systems for
the proposed appendix C1 test procedure. ANSI/ASHRAE 16 is available on
ASHRAE's website at www.ashrae.org.
(3) ANSI/ASHRAE Standard 37-2009, ``Methods of Testing for Rating
Electrically Driven Unitary Air-Conditioning and Heat Pump Equipment,''
approved June 24, 2009.
ANSI/ASHRAE 37 is an industry-accepted test procedure for testing
and rating air-conditioning and heat pump equipment referenced by AHRI
1250-2020. ANSI/ASHRAE 37 includes test provisions related to the
measuring of the capacity of single-packaged dedicated systems for the
proposed appendix C1 test procedure. ANSI/ASHRAE 37 is available on
ASHRAE's website at www.ashrae.org.
(4) ASTM C518-17, ``Standard Test Method for Steady state Thermal
Transmission Properties by Means of the Heat Flow Meter Apparatus,''
approved May 1, 2017.
ASTM C518-17 is an industry-accepted test procedure for measuring
thermal transmission properties using a heat flow meter apparatus. ASTM
C518-17 is available on ASTM's website at www.astm.org.
(5) ASTM C1199-14, ``Standard Test Method for Measuring the Steady
state Thermal Transmittance of Fenestration Systems Using Hot Box
Methods,'' approved February 1, 2014.
[[Page 23985]]
ASTM C1199-14 is an industry-accepted test procedure for measuring
the steady state thermal transmittance of fenestration systems
referenced by NFRC 102-2020. ASTM C1199-14 is available on ASTM's
website at www.astm.org.
(6) NFRC 102-2020 [E0A0], ``Procedure for Measuring the Steady-
State Thermal Transmittance of Fenestration Systems.''
NFRC 102-2020 is an industry-accepted test procedure for measuring
the steady state thermal transmittance of fenestration systems. NFRC
102-2020 is available on NFRC's website at www.nfrc.org/.
The following standards were approved on December 28, 2016, for IBR
into the provisions where they appear in this document and no change in
use is proposed: ANSI/AHRI Standard 420-2008, AHRI Standard 1250 (I-P)-
2009, and ANSI/ASHRAE Standard 23.1-2010.
V. Public Participation
A. Participation in the Webinar
The time and date of the webinar are listed in the DATES section at
the beginning of this document. Webinar registration information,
participant instructions, and information about the capabilities
available to webinar participants will be published on DOE's website:
www.energy.gov/eere/buildings/public-meetings-and-comment-deadlines.
Participants are responsible for ensuring their systems are compatible
with the webinar software.
B. Procedure for Submitting Prepared General Statements for
Distribution
Any person who has an interest in the topics addressed in this
document, or who is representative of a group or class of persons that
has an interest in these issues, may request an opportunity to make an
oral presentation at the webinar. Such persons may submit to
[email protected]. Persons who wish to speak
should include with their request a computer file in WordPerfect,
Microsoft Word, PDF, or text (ASCII) file format that briefly describes
the nature of their interest in this proposed rulemaking and the topics
they wish to discuss. Such persons should also provide a daytime
telephone number where they can be reached.
Persons requesting to speak should briefly describe the nature of
their interest in this rulemaking and provide a telephone number for
contact. DOE requests persons selected to make an oral presentation to
submit an advance copy of their statements at least two weeks before
the webinar. At its discretion, DOE may permit persons who cannot
supply an advance copy of their statement to participate, if those
persons have made advance alternative arrangements with the Building
Technologies Office. As necessary, requests to give an oral
presentation should ask for such alternative arrangements.
C. Conduct of the Webinar
DOE will designate a DOE official to preside at the webinar/public
meeting and may also use a professional facilitator to aid discussion.
The meeting will not be a judicial or evidentiary-type public hearing,
but DOE will conduct it in accordance with section 336 of EPCA (42
U.S.C. 6306). A court reporter will be present to record the
proceedings and prepare a transcript. DOE reserves the right to
schedule the order of presentations and to establish the procedures
governing the conduct of the webinar/public meeting. There shall not be
discussion of proprietary information, costs or prices, market share,
or other commercial matters regulated by U.S. anti-trust laws. After
the webinar/public meeting and until the end of the comment period,
interested parties may submit further comments on the proceedings and
any aspect of the proposed rulemaking.
The webinar/public meeting will be conducted in an informal,
conference style. DOE will present a general overview of the topics
addressed in this proposed rulemaking, allow time for prepared general
statements by participants, and encourage all interested parties to
share their views on issues affecting this proposed rulemaking. Each
participant will be allowed to make a general statement (within time
limits determined by DOE), before the discussion of specific topics.
DOE will permit, as time permits, other participants to comment briefly
on any general statements.
At the end of all prepared statements on a topic, DOE will permit
participants to clarify their statements briefly. Participants should
be prepared to answer questions by DOE and by other participants
concerning these issues. DOE representatives may also ask questions of
participants concerning other matters relevant to this proposed
rulemaking. The official conducting the webinar/public meeting will
accept additional comments or questions from those attending, as time
permits. The presiding official will announce any further procedural
rules or modification of the procedures that may be needed for the
proper conduct of the webinar/public meeting.
A transcript of the webinar/public meeting will be included in the
docket, which can be viewed as described in the Docket section at the
beginning of this proposed rule. In addition, any person may buy a copy
of the transcript from the transcribing reporter.
D. Submission of Comments
DOE will accept comments, data, and information regarding this
proposed rule no later than the date provided in the DATES section at
the beginning of this proposed rule.\94\ Interested parties may submit
comments using any of the methods described in the ADDRESSES section at
the beginning of this document.
---------------------------------------------------------------------------
\94\ DOE has historically provided a 75-day comment period for
test procedure NOPRs pursuant to the North American Free Trade
Agreement, U.S.-Canada-Mexico (``NAFTA''), Dec. 17, 1992, 32 I.L.M.
289 (1993); the North American Free Trade Agreement Implementation
Act, Public Law 103-182, 107 Stat. 2057 (1993) (codified as amended
at 10 U.S.C.A. 2576) (1993) (``NAFTA Implementation Act''); and
Executive Order 12889, ``Implementation of the North American Free
Trade Agreement,'' 58 FR 69681 (Dec. 30, 1993). However, on July 1,
2020, the Agreement between the United States of America, the United
Mexican States, and the United Canadian States (``USMCA''), Nov. 30,
2018, 134 Stat. 11 (i.e., the successor to NAFTA), went into effect,
and Congress's action in replacing NAFTA through the USMCA
Implementation Act, 19 U.S.C. 4501 et seq. (2020), implies the
repeal of E.O. 12889 and its 75-day comment period requirement for
technical regulations. Thus, the controlling laws are EPCA and the
USMCA Implementation Act. Consistent with EPCA's public comment
period requirements for consumer products, the USMCA only requires a
minimum comment period of 60 days. Consequently, DOE now provides a
60-day public comment period for test procedure NOPRs.
---------------------------------------------------------------------------
Submitting comments via www.regulations.gov. The
www.regulations.gov web page will require you to provide your name and
contact information. Your contact information will be viewable to DOE
Building Technologies staff only. Your contact information will not be
publicly viewable except for your first and last names, organization
name (if any), and submitter representative name (if any). If your
comment is not processed properly because of technical difficulties,
DOE will use this information to contact you. If DOE cannot read your
comment due to technical difficulties and cannot contact you for
clarification, DOE may not be able to consider your comment.
However, your contact information will be publicly viewable if you
include it in the comment or in any documents attached to your comment.
Any information that you do not want to be publicly viewable should not
be included in your comment, nor in any document attached to your
comment.
[[Page 23986]]
Persons viewing comments will see only first and last names,
organization names, correspondence containing comments, and any
documents submitted with the comments.
Do not submit to www.regulations.gov information for which
disclosure is restricted by statute, such as trade secrets and
commercial or financial information (hereinafter referred to as
Confidential Business Information (``CBI'')). Comments submitted
through www.regulations.gov cannot be claimed as CBI. Comments received
through the website will waive any CBI claims for the information
submitted. For information on submitting CBI, see the Confidential
Business Information section.
DOE processes submissions made through www.regulations.gov before
posting. Normally, comments will be posted within a few days of being
submitted. However, if large volumes of comments are being processed
simultaneously, your comment may not be viewable for up to several
weeks. Please keep the comment tracking number that www.regulations.gov
provides after you have successfully uploaded your comment.
Submitting comments via email. Comments and documents submitted via
email also will be posted to www.regulations.gov. If you do not want
your personal contact information to be publicly viewable, do not
include it in your comment or any accompanying documents. Instead,
provide your contact information on a cover letter. Include your first
and last names, email address, telephone number, and optional mailing
address. The cover letter will not be publicly viewable as long as it
does not include any comments.
Include contact information each time you submit comments, data,
documents, and other information to DOE. No faxes will be accepted.
Comments, data, and other information submitted to DOE
electronically should be provided in PDF (preferred), Microsoft Word or
Excel, WordPerfect, or text (ASCII) file format. Provide documents that
are not secured, written in English and free of any defects or viruses.
Documents should not contain special characters or any form of
encryption and, if possible, they should carry the electronic signature
of the author.
Campaign form letters. Please submit campaign form letters by the
originating organization in batches of between 50 to 500 form letters
per PDF or as one form letter with a list of supporters' names compiled
into one or more PDFs. This reduces comment processing and posting
time.
Confidential Business Information. Pursuant to 10 CFR 1004.11, any
person submitting information that he or she believes to be
confidential and exempt by law from public disclosure should submit via
email two well-marked copies: One copy of the document marked
confidential including all the information believed to be confidential,
and one copy of the document marked non-confidential with the
information believed to be confidential deleted. DOE will make its own
determination about the confidential status of the information and
treat it according to its determination.
It is DOE's policy that all comments may be included in the public
docket, without change and as received, including any personal
information provided in the comments (except information deemed to be
exempt from public disclosure).
E. Issues on Which DOE Seeks Comment
Although DOE welcomes comments on any aspect of this proposal, DOE
is particularly interested in receiving comments and views of
interested parties concerning the following issues:
Issue 1: DOE requests comment on its proposed changes to the
definition for walk-in cooler and walk-in freezer.
Issue 2: DOE requests feedback on the proposed changes to the
definition of ``door'' and the newly proposed definition for ``door
leaf.'' DOE also seeks comment on the newly proposed definitions for
certain door opening characteristics: ``hinged vertical door,'' ``roll-
up door,'' and ``sliding door.''
Issue 3: DOE requests comment on the proposed definition of
``ducted fan coil unit'' and on the proposed modification to the
``single-packaged dedicated system'' definition.
Issue 4: DOE requests comment on the proposed definition for multi-
circuit single-packaged dedicated refrigeration systems.
Issue 5: DOE requests comment on the proposed definition for
attached split system.
Issue 6: DOE requests comment on the proposed definition for
detachable single-packaged dedicated system.
Issue 7: DOE requests comment on the proposed definition of
CO2 unit coolers. DOE also requests comment on whether any
distinguishing features of CO2 unit coolers exist that could
reliably be used as an alternative approach that can differentiate them
from those unit coolers intended for use with conventional
refrigerants.
Issue 8: DOE requests comment on the proposed definition for hot
gas defrost. Specifically, DOE requests comment on if this proposed
definition is sufficient to identify which equipment is sold with hot
gas defrost capability installed and which is not.
Issue 9: DOE requests feedback on the proposed provisions relating
to test specimen and total insulation thickness and test specimen
preparation prior to conducting the ASTM C518-17 test.
Issue 10: DOE requests feedback on the proposed provisions relating
to determining parallelism and flatness of the test specimen.
Issue 11: DOE seeks comment on other comparable data or studies of
aging of foam panels that are representative of the foam insulation,
blowing agents, and panel construction currently used in the
manufacture of walk-in panels. DOE also requests comment on whether
manufacturers have been certifying R-value at time of manufacture or
after a period of aging.
Issue 12: DOE requests comment on the proposed pretest coil
inspection requirement. DOE requests comment on whether the proposed
approach is inconsistent in any way with the way units under test are
used to assist in chamber conditioning by testing facilities, and if
so, in what way are the proposals inconsistent, and how could they be
changed to align with this practice.
Issue 13: DOE requests comment on its proposal to require use of
thermometer wells or sheathed sensors immersed in the refrigerant when
measuring temperature at the liquid outlet of the condensing unit and
to forego the requirement for this measurement technique for the
suction line when testing a dedicated condensing unit alone.
Issue 14: DOE requests comment on its proposal to allow the use of
two temperature measuring instruments, placed on the outside of
refrigerant tubing that is less than or equal to \1/2\-inch, for the
measurement of refrigerant temperature where the current test procedure
requirement is to use thermometer wells or a sheathed sensor immersed
in the refrigerant.
Issue 15: DOE requests comment on its proposals discussed in this
section regarding set up of walk-in refrigeration systems for testing
to achieve manufacturer-specified conditions for superheat, subcooling,
high-side temperature, pressure or saturation temperature, low-side
temperature, pressure or saturation temperature, and refrigerant charge
weight. Additionally, DOE requests comment on the proposed hierarchy
presented in Table III.6, if a laboratory has confirmed that the unit
is properly charged.
[[Page 23987]]
Issue 16: DOE requests comments on its proposal to clarify the
location where the 3 [deg]F subcooling requirement would apply and to
require active cooling of the liquid line in order to achieve the
required 3 [deg]F subcooling at a refrigerant mass flow meter. DOE also
seeks comment on its proposal to require, for matched pairs, adjustment
of the measured unit cooler inlet temperature by the difference in
temperatures measured upstream and downstream of the active cooling in
order to calculate the inlet enthalpy in the capacity calculation.
Issue 17: DOE requests comment on the appropriateness of
traditional refrigerant compressor EER values for use in CO2
unit cooler AWEF calculations.
Issue 18: DOE requests comment on its proposals to adopt test
procedure provisions for high-temperature unit coolers in appendices C
and C1 of 10 CFR part 431, subpart R.
Issue 19: DOE requests comments on its proposals to align the test
procedures for appendix C1 with AHRI 1250-2020, except for the use of
off-cycle power measurements in the AWEF calculations for dedicated
condensing units, matched pairs, or single-packaged dedicated systems
intended for outdoor installation. DOE requests comments on its
proposals for use in the AWEF calculations of the three sets of unit
cooler and condensing unit off-cycle measurements made for outdoor
refrigeration systems.
Issue 20: DOE requests comment on the proposed single-packaged
refrigerant enthalpy test procedure for evaluating the performance of
single-packaged dedicated systems.
Issue 21: DOE requests comment on testing detachable single-
packaged dedicated systems using the test procedure for single-packaged
dedicated systems.
Issue 22: DOE requests comment on its proposal that attached split
systems be tested using refrigerant enthalpy methods.
Issue 23: DOE requests comment on provisions for setting ESP when
testing ducted units.
Issue 24: DOE requests comments on its proposals for testing
multiple-, variable-, and two-capacity dedicated condensing units
tested alone. DOE specifically requests comments on (a) the expectation
that a unit cooler with which such a condensing unit is paired in the
field would have two-speed (or variable-speed) fans or be fitted with
such fans during installation, (b) the proposed compressor operating
levels to use for testing, (c) the proposed compressor operating level
at which the unit cooler fan would be assumed to switch to half-speed,
(d) the proposed targets for unit cooler exit and condensing unit inlet
refrigerant temperatures and dew point target temperatures, and (e) the
unit cooler half-fan-speed input wattage.
Issue 25: DOE requests comment on whether DOE should set the target
test conditions using correlations for unit cooler and suction line
response to part-load operation rather than the proposed tabular
approach.
Issue 26: DOE requests comment on its proposal to include in its
test procedures instructions for testing and determining
representations for indoor matched pair and single-packaged dedicated
systems.
Issue 27: DOE requests comment on its proposal to modify the
approach for calculating intermediate-capacity EER for variable-speed
refrigeration systems.
Issue 28: DOE requests comments on its proposals to address part-
load testing for refrigeration systems with digital compressors.
Issue 29: DOE requests comment on its proposal to clarify that the
second mass flow measurement for the DX Dual Instrumentation method may
be in the suction line upstream of the inlet to the condensing unit, as
shown in Figure C1 of AHRI 1250-2009.
Issue 30: DOE requests comment on its proposal to adopt the
calculations for evaporator fan power in AHRI 1250-2020.
Issue 31: DOE requests comment on its proposal for rounding AWEF to
the nearest 0.05 Btu/(W-h) and rounding capacity values to the nearest
multiple as presented in Table III.14.
Issue 32: DOE seeks comment on its proposal to allow for the use of
AEDMs to determine the energy consumption rating of walk-in doors. DOE
requests specific feedback on the proposed 5 percent model tolerance
for validating an AEDM, the proposed validation classes and number of
basic models required to be tested per validation class, and the
proposed 5 percent tolerance on the result from a DOE AEDM verification
test.
Issue 33: DOE seeks comment on its proposal to modify and extend
its AEDM validation classes for refrigeration systems, consistent with
the test procedure revisions discussed in this document.
Issue 34: DOE requests comment on its proposal to apply the low-
volume sampling procedures in appendix B of subpart C of 10 CFR part
429 to walk-in doors and panels.
Issue 35: DOE requests comment on its tentative understanding of
the impact of the test procedure proposals for appendix A in this
NOPR--specifically, whether the proposed test procedure amendments, if
finalized, would either not impact or decrease the testing burden for
walk-in door manufacturers when compared to the current DOE test
procedure in appendix A.
Issue 36: DOE requests comment on its tentative understanding of
the impact of the test procedure proposals for appendix B in this
NOPR--specifically, that the proposed test procedure amendments, if
finalized, would not increase testing burden on panel manufacturers
when compared to the current DOE test procedure in appendix B.
Issue 37: DOE requests comment on its tentative understanding of
the impact of the test procedure proposals for refrigeration systems--
specifically, whether DOE's initial conclusion that the proposed DOE
test procedure amendments, if finalized, would increase testing burden.
Issue 38: DOE invites comment on the number of small, domestic OEMs
producing the three principal components of WICFs: Panels, doors, and
refrigeration systems.
Issue 39: DOE requests comment on its cost estimate of impacts on
small, domestic OEMs of doors.
Issue 40: DOE requests comment on its cost estimate of impacts on
small, domestic OEMs of panels.
Issue 41: DOE requests comment on its cost estimate of impacts on
small, domestic OEMs of refrigeration systems.
VI. Approval of the Office of the Secretary
The Secretary of Energy has approved publication of this notice of
proposed rulemaking and announcement of public webinar.
List of Subjects
10 CFR Part 429
Administrative practice and procedure, Confidential business
information, Energy conservation, Household appliances, Reporting and
recordkeeping requirements.
10 CFR Part 431
Administrative practice and procedure, Confidential business
information, Energy conservation test procedures, Incorporation by
reference, and Reporting and recordkeeping requirements.
Signing Authority
This document of the Department of Energy was signed on March 18,
2022, by Kelly J. Speakes-Backman, Principal Deputy Assistant Secretary
for Energy Efficiency and Renewable Energy,
[[Page 23988]]
pursuant to delegated authority from the Secretary of Energy. That
document with the original signature and date is maintained by DOE. For
administrative purposes only, and in compliance with requirements of
the Office of the Federal Register, the undersigned DOE Federal
Register Liaison Officer has been authorized to sign and submit the
document in electronic format for publication, as an official document
of the Department of Energy. This administrative process in no way
alters the legal effect of this document upon publication in the
Federal Register.
Signed in Washington, DC, on March 23, 2022.
Treena V. Garrett,
Federal Register Liaison Officer, U.S. Department of Energy.
For the reasons stated in the preamble, DOE is proposing to amend
parts 429 and 431 of chapter II of title 10, Code of Federal
Regulations as set forth below:
PART 429--CERTIFICATION, COMPLIANCE, AND ENFORCEMENT FOR CONSUMER
PRODUCTS AND COMMERCIAL AND INDUSTRIAL EQUIPMENT
0
1. The authority citation for part 429 continues to read as follows:
Authority: 42 U.S.C. 6291-6317; 28 U.S.C. 2461 note.
0
2. Amend Sec. 429.53 by:
0
a. Revising paragraphs (a)(2)(i) and (a)(3); and
0
b. Adding paragraph (a)(4).
The revisions and addition read as follows:
Sec. 429.53 Walk-in coolers and walk-in freezers.
(a) * * *
(2) * * *
(i) Applicable test procedure. If the AWEF is determined by
testing, test according to the applicable provisions of Sec.
431.304(b) of this chapter with the equipment specific provisions in
paragraphs (a)(2)(i)(A) through (D) of this section.
(A) Dedicated condensing units. Outdoor dedicated condensing
refrigeration systems that are also designated for use in indoor
applications must be tested and rated as both an outdoor dedicated
condensing refrigeration system and an indoor dedicated refrigeration
system.
(B) Matched refrigeration systems. A matched refrigeration system
is not required to be rated if the constituent unit cooler(s) and
dedicated condensing unit have been tested as specified in Sec.
431.304(b)(4) of this chapter. However, if a manufacturer wishes to
represent the efficiency of the matched refrigeration system as
distinct from the efficiency of either constituent component, or if the
manufacturer cannot rate one or both of the constituent components
using the specified method, the manufacturer must test and rate the
matched refrigeration system as specified in Sec. 431.304(b)(4) of
this chapter.
(C) Detachable single-packaged dedicated systems. Detachable
single-packaged dedicated systems must be tested and rated as a single-
packaged dedicated systems using the test procedure in Sec.
431.304(b)(4) of this chapter.
(D) Attached split systems. Attached split systems must be tested
and rated as dedicated condensing units and unit coolers using the test
procedure in Sec. 431.304(b)(4) of this chapter.
* * * * *
(3) For each basic model of walk-in cooler and walk-in freezer
display and non-display door, the daily energy consumption must be
determined by testing, in accordance with Sec. 431.304 of this chapter
and the provisions of this section, or by application of an alternative
efficiency determination method (AEDM) that meets the requirements of
Sec. 429.70 and the provisions of this section.
(i) Applicable test procedure. Prior to [180 days after publication
of final rule], use the test procedure for walk-ins as it appeared in
10 CFR part 431, subpart R, appendix A, revised as of January 1, 2021,
to determine daily energy consumption. Beginning [180 days after
publication of final rule], use the test procedure in part 431, subpart
R, appendix A, of this chapter to determine daily energy consumption.
(ii) Units to be tested. For each basic model, a sample of
sufficient size shall be randomly selected and tested to ensure that
any represented value of daily energy consumption of a basic model or
other measure of energy use for which consumers would favor lower
values shall be greater than or equal to the higher of:
(A) The mean of the sample, where:
[GRAPHIC] [TIFF OMITTED] TP21AP22.000
And x is the sample mean, n is the number of samples, and xi is the
i\th\ sample; or,
(B) The upper 95 percent confidence limit (UCL) of the true mean
divided by 1.05, where:
[GRAPHIC] [TIFF OMITTED] TP21AP22.001
And x is the sample mean, s is the sample standard deviation; n is
the number of samples, and t0.95 is the statistic for a 95%
one-tailed confidence interval with n-1 degrees of freedom (from
appendix A to this subpart).
(4) For each basic model of walk-in cooler and walk-in freezer
panel and non-display door, the R-value must be determined by testing,
in accordance with Sec. 431.304 of this chapter and the provisions of
this section.
(i) Applicable test procedure. Prior to [date 180 days after
publication of final rule], use the test procedure for walk-ins as it
appeared in 10 CFR part 431, subpart R, appendix B, revised as of
January 1, 2021, to determine R-value. Beginning [date 180 days after
publication of final rule], use the test procedure in part 431, subpart
R, appendix B, of this chapter to determine R-value.
(ii) Units to be tested. For each basic model, a sample of
sufficient size shall be randomly selected and tested to ensure that
any represented value of R-value or other measure of efficiency of a
basic model for which consumers would favor higher values shall be less
than or equal to the lower of:
(A) The mean of the sample, where:
[GRAPHIC] [TIFF OMITTED] TP21AP22.002
And x is the sample mean, n is the number of samples, and xi is the
i\th\ sample; or,
(B) The lower 95 percent confidence limit (LCL) of the true mean
divided by 0.95, where:
[GRAPHIC] [TIFF OMITTED] TP21AP22.003
And x is the sample mean, s is the sample standard deviation; n is
the number of samples, and t0.95 is the statistic for a 95%
one-tailed confidence interval with n-1 degree of freedom (from
appendix A to this subpart).
* * * * *
0
3. Amend Sec. 429.70 by:
0
a. Revising paragraphs (f) heading and (f)(2)(ii)(A) and (B);
0
b. Adding paragraph (f)(2)(ii)(C);
0
c. Removing the word ``and'' at the end of paragraphs (f)(2)(iii)(A)
and (C);
0
d. Removing the period at the end of paragraph (f)(2)(iii)(D) and
adding ``; and'' in its place;
0
e. Adding paragraph (f)(2)(iii)(E); and
0
f. Revising paragraphs (f)(2)(iv) and (f)(5)(vi).
[[Page 23989]]
The revisions and additions read as follows:
Sec. 429.70 Alternative methods for determining energy efficiency and
energy use.
* * * * *
(f) Alternative efficiency determination method (AEDM) for walk-in
refrigeration systems and doors-- * * *
(2) * * *
(ii) * * *
(A) For refrigeration systems, which are subject to an energy
efficiency metric, the predicted efficiency for each model calculated
by applying the AEDM may not be more than five percent greater than the
efficiency determined from the corresponding test of the model.
(B) For doors, which are subject to an energy consumption metric
the predicted daily energy consumption for each model calculated by
applying the AEDM may not be more than five percent less than the daily
energy consumption determined from the corresponding test of the model.
(C) The predicted energy efficiency or energy consumption for each
model calculated by applying the AEDM must meet or exceed the
applicable Federal energy conservation standard.
(iii) * * *
(E) For rating doors, an AEDM may not simulate or model components
of the door that are not required to be tested by the DOE test
procedure. That is, if the test results used to validate the AEDM are
for the U-factor test of the door, the AEDM must estimate the daily
energy consumption, specifically the conduction thermal load, and the
direct and indirect electrical energy consumption, using the nominal
values and calculation procedure specified in the DOE test procedure.
(iv) Walk-in coolers and freezers (WICF) validation classes--(A)
Doors.
Table 1 to Paragraph (f)(2)(iv)(A)
------------------------------------------------------------------------
Minimum number of distinct
Validation class models that must be tested
------------------------------------------------------------------------
Display Doors, Medium Temperature....... 2 Basic Models.
Display Doors, Low Temperature.......... 2 Basic Models.
Non-display Doors, Medium Temperature... 2 Basic Models.
Non-display Doors, Low Temperature...... 2 Basic Models.
------------------------------------------------------------------------
(B) Refrigeration systems. (1) For representations made prior to
the compliance date of revised energy conservation standards for walk-
in cooler and walk-in freezer refrigeration systems, use the following
validation classes.
Table 2 to Paragraph (f)(2)(iv)(B)(1)
------------------------------------------------------------------------
Minimum number of distinct
Validation class models that must be tested
------------------------------------------------------------------------
Dedicated Condensing, Medium 2 Basic Models.
Temperature, Matched Pair Indoor System.
Dedicated Condensing, Medium 2 Basic Models.
Temperature, Matched Pair Outdoor
System.\1\
Dedicated Condensing, Low Temperature, 2 Basic Models.
Matched Pair Indoor System.
Dedicated Condensing, Low Temperature, 2 Basic Models.
Matched Pair Outdoor System.\1\
Unit Cooler, High-temperature........... 2 Basic Models.
Unit Cooler, Medium Temperature......... 2 Basic Models.
Unit Cooler, Low Temperature............ 2 Basic Models.
Medium Temperature, Indoor Condensing 2 Basic Models.
Unit.
Medium Temperature, Outdoor Condensing 2 Basic Models.
Unit.\1\
Low Temperature, Indoor Condensing Unit. 2 Basic Models.
Low Temperature, Outdoor Condensing 2 Basic Models.
Unit.\1\
------------------------------------------------------------------------
\1\ AEDMs validated for an outdoor class by testing only outdoor models
of that class may be used to determine representative values for the
corresponding indoor class, and additional validation testing is not
required. AEDMs validated only for a given indoor class by testing
indoor models or a mix of indoor and outdoor models may not be used to
determine representative values for the corresponding outdoor class.
(2) For representations made on or after the compliance date of
revised energy conservation standards for walk-in cooler and walk-in
freezer refrigeration systems, use the following validation classes.
Table 3 to Paragraph (f)(2)(iv)(B)(2)
------------------------------------------------------------------------
Minimum number of distinct
Validation class models that must be tested
------------------------------------------------------------------------
Dedicated Condensing Unit, Medium 2 Basic Models.
Temperature, Indoor System.
Dedicated Condensing Unit, Medium 2 Basic Models.
Temperature, Outdoor System.\1\
Dedicated Condensing Unit, Low 2 Basic Models.
Temperature, Indoor System.
Dedicated Condensing Unit, Low 2 Basic Models.
Temperature, Outdoor System.\1\
Single-packaged Dedicated Condensing, 2 Basic Models.
High-temperature, Indoor System.
[[Page 23990]]
Single-packaged Dedicated Condensing, 2 Basic Models.
High-temperature, Outdoor System.\1\
Single-packaged Dedicated Condensing, 2 Basic Models.
Medium Temperature, Indoor System.
Single-packaged Dedicated Condensing, 2 Basic Models.
Medium Temperature, Outdoor System.\1\
Single-packaged Dedicated Condensing, 2 Basic Models.
Low Temperature, Indoor System.
Single-packaged Dedicated Condensing, 2 Basic Models.
Low Temperature, Indoor System.\1\
Matched Pair, High-temperature, Indoor 2 Basic Models.
Condensing Unit.
Matched Pair, High-temperature, Outdoor 2 Basic Models.
Condensing Unit.\1\
Matched Pair, Medium Temperature, Indoor 2 Basic Models.
Condensing Unit.
Matched Pair, Medium Temperature, 2 Basic Models.
Outdoor Condensing Unit.\1\
Matched Pair, Low Temperature, Indoor 2 Basic Models.
Condensing Unit.
Matched Pair, Low Temperature, Outdoor 2 Basic Models.
Condensing Unit.\1\
Unit Cooler, High-temperature........... 2 Basic Models.
Unit Cooler, Medium Temperature......... 2 Basic Models.
Unit Cooler, Low Temperature............ 2 Basic Models.
------------------------------------------------------------------------
\1\ AEDMs validated for an outdoor class by testing only outdoor models
of that class may be used to determine representative values for the
corresponding indoor class, and additional validation testing is not
required. AEDMs validated only for a given indoor class by testing
indoor models or a mix of indoor and outdoor models may not be used to
determine representative values for the corresponding outdoor class.
* * * * *
(5) * * *
(vi) Tolerances. For efficiency metrics, the result from a DOE
verification test must be greater than or equal to the certified rating
x (1 - the applicable tolerance). For energy consumption metrics, the
result from a DOE verification test must be less than or equal to the
certified rating x (1 + the applicable tolerance).
Table 4 to Paragraph (f)(5)(vi)
------------------------------------------------------------------------
Applicable
Equipment Metric tolerance
------------------------------------------------------------------------
Refrigeration systems (including AWEF................ 5%
components).
Doors............................. Daily Energy 5%
Consumption.
------------------------------------------------------------------------
* * * * *
0
4. Amend Sec. 429.110 by revising paragraph (e)(2) to read as follows:
Sec. 429.110 Enforcement testing.
* * * * *
(e) * * *
(2) For automatic commercial ice makers; commercial refrigerators,
freezers, and refrigerator-freezers; refrigerated bottled or canned
vending machines; commercial air conditioners and heat pumps;
commercial packaged boilers; commercial warm air furnaces; commercial
water heating equipment; and walk-in cooler and walk-in freezer doors,
panels, and refrigeration systems, DOE will use an initial sample size
of not more than four units and follow the sampling plans in appendix B
of this subpart (Sampling Plan for Enforcement Testing of Covered
Equipment and Certain Low-Volume Covered Products).
* * * * *
0
5. Amend Sec. 429.134 by:
0
a. Adding paragraph (q) introductory text; and
0
b. Revising paragraphs (q)(2) and (4).
The addition and revisions read as follows:
Sec. 429.134 Product-specific enforcement provisions.
* * * * *
(q) * * * Prior to [date 180 days after final rule publication],
the provisions in 10 CFR 429.134, revised as of January 1, 2021, are
applicable. On and after [date 180 days after final rule publication],
the provisions in paragraphs (q)(1) through (4) of this section apply.
* * * * *
(2) Verification of refrigeration system net capacity. The net
capacity of the refrigeration system basic model will be measured
pursuant to the test requirements of part 431, subpart R, appendix C,
of this chapter for each unit tested on and after [date 180 days after
final rule publication] but before the compliance date of revised
energy conservation standards for walk-in cooler and walk-in freezer
refrigeration systems. The net capacity of the refrigeration system
basic model will be measured pursuant to the test requirements of part
431, subpart R, appendix C1, of this chapter for each unit tested on
and after the compliance date of revised energy conservation standards
for walk-in cooler and walk-in freezer refrigeration systems. The
results of the measurement(s) will be averaged and compared to the
value of net capacity certified by the manufacturer. The certified net
capacity will be considered valid only if the average measured net
capacity is within plus or minus five percent of the certified net
capacity.
* * * * *
(4) Verification of door electricity-consuming device power. For
each basic model of walk-in cooler and walk-in freezer door, DOE will
calculate the door's energy consumption using the input power listed on
the nameplate of each electricity-consuming device shipped with the
door. If an electricity-consuming device shipped with a walk-in door
does not have a nameplate or the nameplate does not list the device's
input power, then DOE will use the device's rated input power included
in the door's certification report. If the door is not certified or if
the certification does not include a rated input power for an
electricity-consuming device shipped with a walk-in door, DOE will use
the measured input power. DOE also may validate the power listed on the
nameplate or the rated input power by measuring it when
[[Page 23991]]
energized using a power supply that provides power within the allowable
voltage range listed on the component nameplate or the door nameplate,
whichever is available. If the measured input power is more than 10
percent higher than the input power listed on the nameplate or the
rated input power, as appropriate, then the measured input power shall
be used in the door's energy consumption calculation.
(i) For electricity-consuming devices with controls, the maximum
input wattage observed while energizing the device and activating the
control shall be considered the measured input power. For anti-sweat
heaters that are controlled based on humidity levels, the control may
be activated by increasing relative humidity in the region of the
controls without damaging the sensor. For lighting fixtures that are
controlled with motion sensors, the control may be activated by
simulating motion in the vicinity of the sensor. Other kinds of
controls may be activated based on the functions of their sensor.
(ii) [Reserved]
* * * * *
PART 431--ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND
INDUSTRIAL EQUIPMENT
0
6. The authority citation for part 431 continues to read as follows:
Authority: 42 U.S.C. 6291-6317; 28 U.S.C. 2461 note.
0
7. Amend Sec. 431.302 by:
0
a. Adding, in alphabetical order, definitions for ``Attached split
system,'' ``CO2 unit cooler,'' and ``Detachable single-
packaged dedicated system'';
0
b. Revising the definition for ``Door'';
0
c. Adding, in alphabetical order, definitions for ``Door leaf,'' ``Door
surface area,'' ``Ducted fan coil unit,'' ``High-temperature
refrigeration system,'' ``Hinged vertical door,'' ``Hot gas defrost,''
``Multi-circuit single-packaged dedicated system,'' ``Non-display
door,'' and ``Roll-up door'';
0
d. Revising the definition of ``Single-packaged dedicated system'';
0
e. Adding, in alphabetical order, the definition for ``Sliding door'';
and
0
f. Revising the definition of ``Walk-in cooler and walk-in freezer'';
The additions and revisions read as follows:
Sec. 431.302 Definitions concerning walk-in coolers and walk-in
freezers.
* * * * *
Attached split system means a matched pair refrigeration system
which is designed to be installed with the evaporator entirely inside
the walk-in enclosure and the condenser entirely outside the walk-in
enclosure, and the evaporator and condenser are permanently connected
with structural members extending through the walk-in wall.
* * * * *
CO2 unit cooler means a unit cooler that includes a
nameplate listing only CO2 as an approved refrigerant.
* * * * *
Detachable single-packaged dedicated system means a system
consisting of a dedicated condensing unit and an insulated evaporator
section in which the evaporator section is designed to be installed
external to the walk-in enclosure and circulating air through the
enclosure wall, and the condensing unit is designed to be installed
either attached to the evaporator section or mounted remotely with a
set of refrigerant lines connecting the two components.
* * * * *
Door means an assembly installed in an opening of an interior or
exterior wall that is used to allow access or close off the opening and
that is movable in a sliding, pivoting, hinged, or revolving manner of
movement. For walk-in coolers and walk-in freezers, a door includes the
frame (including mullions), the door leaf or multiple leaves (including
glass) within the frame, and any other elements that form the assembly
or part of its connection to the wall.
Door leaf means the pivoting, rolling, sliding, or swinging portion
of a door.
Door surface area means the product of the height and width of a
walk-in door measured external to the walk-in. The height and width
dimensions shall be perpendicular to each other and parallel to the
wall or panel of the walk-in to which the door is affixed. The height
and width measurements extend to the edge of the frame and frame flange
(as applicable) to which the door is affixed. The surface area of a
display door is represented as Add and the surface area of a non-
display door is represented as And.
Ducted fan coil unit means an assembly, including means for forced
air circulation capable of moving air against both internal and non-
zero external flow resistance, and elements by which heat is
transferred from air to refrigerant to cool the air, with provision for
ducted installation.
* * * * *
High-temperature refrigeration system means a refrigeration system
which is not designed to operate below 45 [deg]F.
Hinged vertical door means a door with a leaf (or leaves) with a
hinge (or hinges) connecting one vertical edge of the leaf (or leaves)
to a frame or mullion of the door. This includes doors that swing open
in one direction (i.e., into or out of the walk-in) and free-swinging
doors that open both into and out of the walk-in.
Hot gas defrost means a factory-installed system where refrigerant
is used to transfer heat from ambient outside air, to the compressor,
and/or a thermal storage component that stores heat when the compressor
is running and uses this stored heat to defrost the evaporator coils.
* * * * *
Multi-circuit single-packaged dedicated system means a single-
packaged dedicated system (as defined in this section) that contains
two or more refrigeration circuits that refrigerate a single stream of
circulated air.
Non-display door means a door that is not a display door.
* * * * *
Roll-up door means a door that bi-directionally rolls open and
closed in a vertical and horizontal manner and includes vertical jamb
tracks.
Single-packaged dedicated system means a refrigeration system (as
defined in this section) that is a single-packaged assembly that
includes one or more compressors, a condenser, a means for forced
circulation of refrigerated air, and elements by which heat is
transferred from air to refrigerant.
Sliding door means a door having one or more manually-operated or
motorized leaves within a common frame that slide horizontally or
vertically.
* * * * *
Walk-in cooler and walk-in freezer means an enclosed storage space
including, but not limited to, panels, doors, and refrigeration system,
refrigerated to temperatures, respectively, above, and at or below 32
degrees Fahrenheit that can be walked into, and has a total chilled
storage area of less than 3,000 square feet; however, the terms do not
include products designed and marketed exclusively for medical,
scientific, or research purposes.
* * * * *
0
8. Amend Sec. 431.303 by:
0
a. Revising paragraph (a);
0
b. Adding paragraph (b)(3);
0
c. Revising paragraphs (c), (d), and (e)(1).
The revisions and additions read as follows:
Sec. 431.303 Materials incorporated by reference.
(a) Certain material is incorporated by reference into this subpart
with the
[[Page 23992]]
approval of the Director of the Federal Register in accordance with 5
U.S.C. 552(a) and 1 CFR part 51. To enforce any edition other than that
specified in this section, DOE must publish a document in the Federal
Register and the material must be available to the public. All approved
material is available for inspection at DOE, and at the National
Archives and Records Administration (``NARA''). Contact DOE at the U.S.
Department of Energy, Office of Energy Efficiency and Renewable Energy,
Building Technologies Program, Sixth Floor, 950 L'Enfant Plaza SW,
Washington, DC 20024, (202) 586-9127, [email protected],
www.energy.gov/eere/buildings/building-technologies-office. For
information on the availability of this material at NARA, email:
[email protected], or go to: www.archives.gov/federal-register/cfr/ibr-locations.html. The material may be obtained from the sources
in the following paragraphs of this section.
(b) * * *
(3) AHRI Standard 1250-2020 (``AHRI 1250-2020''), ``Standard for
Performance Rating of Walk-in Coolers and Freezers,'' copyright 2020.
IBR approved for appendix C1 to subpart R.
(c) ASHRAE. American Society of Heating, Refrigerating and Air-
Conditioning Engineers, 180 Technology Parkway, Peachtree Corners, GA
30092; (404) 636-8400; www.ashrae.org.
(1) ANSI/ASHRAE Standard 16-2016, (``ANSI/ASHRAE 16''), ``Method of
Testing for Rating Room Air Conditioners, Packaged Terminal Air
Conditioners, and Packaged Terminal Heat Pumps for Cooling and Heating
Capacity,'' approved October 31, 2016, IBR approved for appendix C1 to
subpart R.
(2) ANSI/ASHRAE Standard 23.1-2010, (``ASHRAE 23.1-2010''),
``Methods of Testing for Rating the Performance of Positive
Displacement Refrigerant Compressors and Condensing Units that Operate
at Subcritical Temperatures of the Refrigerant,'' ANSI approved January
28, 2010, IBR approved for appendix C to subpart R of part 431.
(3) ANSI/ASHRAE Standard 37-2009, (``ANSI/ASHRAE 37''), ``Methods
of Testing for Rating Electrically Driven Unitary Air-Conditioning and
Heat Pump Equipment,'' ASHRAE approved June 24, 2009, IBR approved for
appendices C and C1 to subpart R.
(d) ASTM. ASTM, International, 100 Barr Harbor Drive, West
Conshohocken, PA 19428-2959; (610) 832-9500; www.astm.org.
(1) ASTM C518-17, (``ASTM C518-17''), ``Standard Test Method for
Steady-State Thermal Transmission Properties by Means of the Heat Flow
Meter Apparatus,'' approved May 1, 2017, IBR approved for appendix B to
subpart R.
(2) ASTM C1199-14, (``ASTM C1199-14''), ``Standard Test Method for
Measuring the Steady-State Thermal Transmittance of Fenestration
Systems Using Hot Box Methods,'' approved February 1, 2014, IBR
approved for appendix A to subpart R.
(e) * * *
(1) NFRC 102-2020 [E0A0], (``NFRC 102-2020''), ``Procedure for
Measuring the Steady-State Thermal Transmittance of Fenestration
Systems,'' IBR approved for appendix A to subpart R.
* * * * *
0
9. Amend Sec. 431.304 by revising paragraph (b) to read as follows:
Sec. 431.304 Uniform test method for the measurement of energy
consumption of walk-in coolers and walk-in freezers.
* * * * *
(b) Testing and Calculations. Determine the energy efficiency and/
or energy consumption of the specified walk-in cooler and walk-in
freezer components by conducting the appropriate test procedure as
follows:
(1) Display panels. Determine the energy use of walk-in cooler and
walk-in freezer display panels by conducting the test procedure set
forth in appendix A to this subpart.
(2) Display doors and non-display doors. Determine the energy use
of walk-in cooler and walk-in freezer display doors and non-display
doors by conducting the test procedure set forth in appendix A to this
subpart.
(3) Non-display panels and non-display doors. Determine the R-value
of insulation of walk-in cooler and walk-in freezer non-display panels
and non-display doors by conducting the test procedure set forth in
appendix B to this subpart.
(4) Refrigeration systems. Determine the Annual Walk-in Energy
Factor (AWEF) and net capacity of walk-in cooler and walk-in freezer
refrigeration systems by conducting the test procedures set forth in
appendix C or C1 to this subpart, as applicable. Refer to the notes at
the beginning of those appendices to determine the applicable appendix
to use for testing.
(i) For unit coolers: Follow the general testing provisions in
sections 3.1 and 3.2 of appendices C or C1 to this subpart, and the
equipment-specific provisions in section 3.3 of appendix C or sections
4.5 through 4.8 of appendix C1.
(ii) For dedicated condensing units: Follow the general testing
provisions in sections 3.1 and 3.2 of appendices C or C1 to this
subpart, and the product-specific provisions in section 3.4 of appendix
C or sections 4.5 through 4.8 of appendix C1.
(iii) For single-packaged dedicated systems: Follow the general
testing provisions in sections 3.1 and 3.2 of appendices C or C1 to
this subpart, and the product-specific provisions in section 3.3 of
appendix C or sections 4.5 through 4.8 of appendix C1.
0
10. Revise appendix A to subpart R of part 431 to read as follows:
Appendix A to Subpart R of Part 431--Uniform Test Method for the
Measurement of Energy Consumption of the Components of Envelopes of
Walk-in Coolers and Walk-in Freezers
Note: Prior to [date 180 days after publication of final rule],
representations with respect to the energy use of envelope
components of walk-in coolers and walk-in freezers, including
compliance certifications, must be based on testing conducted in
accordance with the applicable provisions of 10 CFR part 431,
subpart R, appendix A, revised as of January 1, 2022. Beginning
[date 180 days after publication of final rule], representations
with respect to energy use of envelope components of walk-in coolers
and walk-in freezers, including compliance certifications, must be
based on testing conducted in accordance with this appendix.
Incorporation by Reference
DOE incorporated by reference in Sec. 431.303 the entire
standards for NFRC 102-2020, and ASTM C1199-14. However, certain
enumerated provisions of these standards, as set forth in sections
0.1 and 0.2 of this appendix are inapplicable. To the extent that
there is a conflict between the terms or provisions of a referenced
industry standard and the CFR, the CFR provisions control.
0.1 NFRC 102-2020
0.1.1 Section 1 Scope, is inapplicable as specified in section
5.1.1.1 of this appendix,
0.1.2 Section 4 Significance and Use, is inapplicable as
specified in section 5.1.1.2 of this appendix,
0.1.3 Section 7.3 Test Conditions, is inapplicable as specified
in section 5.1.1.3 of this appendix,
0.1.4 Section 10 Report, is inapplicable as specified in section
5.1.1.4 of this appendix,
0.1.5 Section 11 Precision and Bias, is inapplicable as
specified in section 5.1.1.5 of this appendix,
0.1.6 Annex A3 Standard Test Method for Determining the Thermal
Transmittance of Tubular Daylighting Devices, is inapplicable as
specified in section 5.1.1.6 of this appendix, and
0.1.7 Annex A5 Tables and Figures, is inapplicable as specified
in section 5.1.1.7 of this appendix.
0.2 ASTM C1199-14
0.2.1 Section 1 Scope, is inapplicable as specified in section
5.1.2.1 of this appendix,
0.2.2 Section 4 Significance and Use is inapplicable as
specified in section 5.1.2.2 of this appendix,
[[Page 23993]]
0.2.3 Section 7.3 Test Conditions, is inapplicable as specified
in section 5.1.2.3 of this appendix,
0.2.4 Section 10 Report, is inapplicable as specified in section
5.1.2.4 of this appendix, and
0.2.5 Section 11 Precision and Bias, is inapplicable as
specified in section 5.1.2.5 of this appendix.
1. General. The following sections of this appendix provide
additional instructions for testing. In cases where there is a
conflict, the language of this appendix takes highest precedence,
followed by NFRC 102-2020, followed by ASTM C1199-14. Any subsequent
amendment to a referenced document by the standard-setting
organization will not affect the test procedure in this appendix,
unless and until the test procedure is amended by DOE. Material is
incorporated as it exists on the date of the approval, and a
notification of any change in the incorporation will be published in
the Federal Register.
2. Scope.
This appendix covers the test requirements used to measure the
energy consumption of the components that make up the envelope of a
walk-in cooler or walk-in freezer.
3. Definitions.
The definitions contained in Sec. 431.302 are applicable to
this appendix.
4. Additional Definitions.
4.1 Automatic door opener/closer means a device or control
system that ``automatically'' opens and closes doors without direct
user contact, such as a motion sensor that senses when a forklift is
approaching the entrance to a door and opens it, and then closes the
door after the forklift has passed.
4.2 Percent time off (PTO) means the percent of time that an
electrical device is assumed to be off.
4.3 Rated power means the input power of an electricity-
consuming device as specified on the device's nameplate. If the
device does not have a nameplate or such nameplate does not list the
device's input power, then the rated power must be determined from
the device's product data sheet, literature, or installation
instructions that come with the device or are available online.
4.4 Rating conditions means, unless explicitly stated otherwise,
all conditions shown in Table A.1 of this appendix.
Table A.1--Temperature Conditions
------------------------------------------------------------------------
------------------------------------------------------------------------
Internal Temperatures (cooled space within the envelope)
------------------------------------------------------------------------
Cooler Dry Bulb Temperature............... 35 [deg]F.
Freezer Dry Bulb Temperature.............. -10 [deg]F.
------------------------------------------------------------------------
External Temperatures (space external to the envelope)
------------------------------------------------------------------------
Freezer and Cooler Dry Bulb Temperatures.. 75 [deg]F.
------------------------------------------------------------------------
5. Test Methods and Measurements.
5.1 U-factor Test of Doors and Display Panels.
Determine the U-factor of the entire door or display panel,
including the frame, in accordance with the specified sections of
NFRC 1022020 and ASTM C1199-14 at the temperature conditions listed
in Table A.1 of this appendix; however, the following enumerated
provisions of NFRC 102-2020 and ASTM C1199-14 are not applicable, as
set forth in sections 5.1.1 and 5.1.2 of this appendix.
5.1.1 Excepted sections of NFRC 102-2020.
5.1.1.1 Section 1 Scope,
5.1.1.2 Section 4 Significance and Use,
5.1.1.3 Section 7.3 Test Conditions,
5.1.1.4 Section 10 Report,
5.1.1.5 Section 11 Precision and Bias,
5.1.1.6 Annex A3 Standard Test Method for Determining the
Thermal Transmittance of Tubular Daylighting Devices, and
5.1.1.7 Annex A5 Tables and Figures.
5.1.2 Excepted sections of ASTM C1199-14.
5.1.2.1 Section 1 Scope,
5.1.2.2 Section 4 Significance and Use,
5.1.2.3 Section 7.3 Test Conditions,
5.1.2.4 Section 10 Report, and
5.1.2.5 Section 11 Precision and Bias.
5.2 Required Test Measurements.
5.2.1 For display doors and display panels, thermal
transmittance, Udd or Udp, respectively, shall
be the standardized thermal transmittance, UST,
determined per section 5.1.1 of this appendix.
5.2.2 For non-display doors, thermal transmittance,
Und, shall be the standardized thermal transmittance,
UST, determined per section 5.1 of this appendix.
5.2.3 Projected area of the test specimen, As, in ft\2\, as
referenced in ASTM C1199-14.
6. Calculations.
6.1 Display Panels.
6.1.1 Determine the U-factor of the display panel in accordance
with section 5.1 of this appendix, in units of Btu/(h-ft\2\-[deg]F).
6.1.2 Calculate the temperature differential,
[Delta]Tdp, [deg]F, for the display panel, as follows:
[GRAPHIC] [TIFF OMITTED] TP21AP22.004
Where:
TDB,ext,dp = dry-bulb air external temperature, [deg]F,
as prescribed in Table A.1 of this appendix; and
TDB,int,dp = dry-bulb air temperature internal to the
cooler or freezer, [deg]F, as prescribed in Table A.1 of this
appendix.
6.1.3 Calculate the conduction load through the display panel,
Qcond-dp, Btu/h, as follows:
[GRAPHIC] [TIFF OMITTED] TP21AP22.005
Where:
As = projected area of the test specimen (same as the
test specimen aperture in the surround panel) or the area used to
determine the U-factor in section 5.1 of this appendix, ft\2\;
[Delta]Tdp = temperature differential between
refrigerated and adjacent zones, [deg]F; and
Udp = thermal transmittance, U-factor, of the display
panel in accordance with section 5.1 of this appendix, Btu/(h-ft\2\-
[deg]F).
6.1.4 Calculate the total daily energy consumption,
Edp, kWh/day, as follows:
[GRAPHIC] [TIFF OMITTED] TP21AP22.006
Where:
Qcond,dp = the conduction load through the display panel,
Btu/h; and
EER = Energy Efficiency Ratio of walk-in (cooler or freezer), Btu/W-
h. For coolers, use EER = 12.4 Btu/W-h. For freezers, use EER = 6.3
Btu/W-h.
6.2 Display Doors.
6.2.1 Conduction Through Display Doors.
6.2.1.1 Determine the U-factor of the display door in accordance
with section 5.1 of this appendix, in units of Btu/(h-ft\2\-[deg]F).
6.2.1.2 Calculate the temperature differential,
[Delta]Tdd, [deg]F, for the display door as follows:
[[Page 23994]]
[GRAPHIC] [TIFF OMITTED] TP21AP22.007
Where:
TDB,ext,dd = dry-bulb air temperature external to the
display door, [deg]F, as prescribed in Table A.1 of this appendix;
and
TDB,int,dd = dry-bulb air temperature internal to the
display door, [deg]F, as prescribed in Table A.1 of this appendix.
6.2.1.3 Calculate the conduction load through the display doors,
Qcond,dd, Btu/h, as follows:
[GRAPHIC] [TIFF OMITTED] TP21AP22.008
Where:
As = projected area of the test specimen (same as the
test specimen aperture in the surround panel) or the area used to
determine the U-factor in section 5.1 of this appendix, ft\2\;
[Delta]Tdd = temperature differential between
refrigerated and adjacent zones, [deg]F; and
Udd = thermal transmittance, U-factor of the door, in
accordance with section 5.1 of this appendix, Btu/(h-ft\2\-[deg]F).
6.2.1.4 Calculate the total daily energy consumption due to
conduction thermal load, Edd,thermal, kWh/day, as
follows:
[GRAPHIC] [TIFF OMITTED] TP21AP22.009
Where:
Qcond,dd = the conduction load through the display door,
Btu/h; and
EER = EER of walk-in (cooler or freezer), Btu/W-h. For coolers, use
EER = 12.4 Btu/(W-h). For freezers, use EER = 6.3 Btu/(W-h).
6.2.2 Direct Energy Consumption of Electrical Component(s) of
Display Doors.
Electrical components associated with display doors could
include but are not limited to: Heater wire (for anti-sweat or anti-
freeze application); lights; door motors; control system units; and
sensors.
6.2.2.1 Select the required value for percent time off (PTO) for
each type of electricity-consuming device per Table A.2 of this
appendix, PTOt (%).
Table A.2--Percent Time Off Values
----------------------------------------------------------------------------------------------------------------
Percent time
Device Temperature condition Controls off value (%)
----------------------------------------------------------------------------------------------------------------
Lights.................................. All....................... Without................... 25
With...................... 50
Anti-sweat heaters...................... All....................... Without................... 0
Coolers................... With...................... 75
Freezers.................. With...................... 50
Door motors............................. All....................... .......................... 97
All other electricity-consuming devices. All....................... Without................... 0
With...................... 25
----------------------------------------------------------------------------------------------------------------
6.2.2.2 Calculate the power usage for each type of electricity-
consuming device, Pdd,comp,u,t, kWh/day, as follows:
[GRAPHIC] [TIFF OMITTED] TP21AP22.010
Where:
u = the index for each of type of electricity-consuming device
located on either (1) the interior facing side of the display door
or within the inside portion of the display door, (2) the exterior
facing side of the display door, or (3) any combination of (1) and
(2). For purposes of this calculation, the interior index is
represented by u = int and the exterior index is represented by u =
ext. If the electrical component is both on the interior and
exterior side of the display door then use u = int. For anti-sweat
heaters sited anywhere in the display door, 75 percent of the total
power is be attributed to u = int and 25 percent of the total power
is attributed to u = ext;
t = index for each type of electricity-consuming device with
identical rated power;
Prated,u,t = rated input power of each component, of type
t, kW;
PTOu,t = percent time off, for device of type t, %; and
nu,t = number of devices at the rated input power of type
t, unitless.
6.2.2.3 Calculate the total electrical energy consumption for
interior and exterior power, Pdd,tot,int (kWh/day) and
Pdd,tot,ext (kWh/day), respectively, as follows:
[[Page 23995]]
[GRAPHIC] [TIFF OMITTED] TP21AP22.011
Where:
t = index for each type of electricity-consuming device with
identical rated input power;
Pdd,comp,int,t = the energy usage for an electricity-
consuming device sited on the interior facing side of or in the
display door, of type t, kWh/day; and
Pdd,comp,ext,t = the energy usage for an electricity-
consuming device sited on the external facing side of the display
door, of type t, kWh/day.
6.2.2.4 Calculate the total electrical energy consumption,
Pdd,tot, (kWh/day), as follows:
[GRAPHIC] [TIFF OMITTED] TP21AP22.012
Where:
Pdd,tot,int = the total interior electrical energy usage
for the display door, kWh/day; and
Pdd,tot,ext = the total exterior electrical energy usage
for the display door, kWh/day.
6.2.3 Total Indirect Electricity Consumption Due to Electrical
Devices.
Calculate the additional refrigeration energy consumption due to
thermal output from electrical components sited inside the display
door, Cdd,load, kWh/day, as follows:
[GRAPHIC] [TIFF OMITTED] TP21AP22.013
Where:
Pdd,tot,int = The total internal electrical energy
consumption due for the display door, kWh/day; and
EER = EER of walk-in cooler or walk-in freezer, Btu/W-h. For
coolers, use EER = 12.4 Btu/(W-h). For freezers, use EER = 6.3 Btu/
(W-h).
6.2.4 Total Display Door Energy Consumption.
Calculate the total energy, Edd,tot, kWh/day,
[GRAPHIC] [TIFF OMITTED] TP21AP22.014
Where:
Edd,thermal = the total daily energy consumption due to
thermal load for the display door, kWh/day;
Pdd,tot = the total electrical load, kWh/day; and
Cdd,load = additional refrigeration load due to thermal
output from electrical components contained within the display door,
kWh/day.
6.3 Non-Display Doors.
6.3.1 Conduction Through Non-Display Doors.
6.3.1.1 Determine the U-factor of the non-display door in
accordance with section 5.1 of this appendix, in units of Btu/(h-
ft\2\-[deg]F).
6.3.1.2 Calculate the temperature differential of the non-
display door, [Delta]Tnd, [deg]F, as follows:
[GRAPHIC] [TIFF OMITTED] TP21AP22.015
Where:
TDB,ext,nd = dry-bulb air external temperature, [deg]F,
as prescribed by Table A.1 of this appendix; and
TDB,int,nd = dry-bulb air internal temperature, [deg]F,
as prescribed by Table A.1 of this appendix. If the component spans
both cooler and freezer spaces, the freezer temperature must be
used.
6.3.1.3 Calculate the conduction load through the non-display
door: Qcond,nd, Btu/h,
[GRAPHIC] [TIFF OMITTED] TP21AP22.016
Where:
As = projected area of the test specimen (same as the
test specimen aperture in the surround panel) or the area used to
determine the U-factor in section 5.1 of this appendix, ft\2\;
[Delta]Tnd = temperature differential across the non-
display door, [deg]F; and
Und = thermal transmittance, U-factor of the door, in
accordance with section 5.1 of this appendix, Btu/(h-ft\2\-[deg]F).
6.3.1.4 Calculate the total daily energy consumption due to
thermal load, End,thermal, kWh/day, as follows:
[GRAPHIC] [TIFF OMITTED] TP21AP22.017
[[Page 23996]]
Where:
Qcond,nd = the conduction load through the non-display
door, Btu/h; and
EER = EER of walk-in (cooler or freezer), Btu/W-h. For coolers, use
EER = 12.4 Btu/(W-h). For freezers, use EER = 6.3 Btu/(W-h).
6.3.2 Direct Energy Consumption of Electrical Components of Non-
Display Doors.
Electrical components associated with non-display doors comprise
could include, but are not limited to: Heater wire (for anti-sweat
or anti-freeze application), lights, door motors, control system
units, and sensors.
6.3.2.1 Select the required value for percent time off for each
type of electricity-consuming device per Table A.2 of this appendix,
PTOt (%).
6.3.2.2 Calculate the power usage for each type of electricity-
consuming device, Pnd,comp,u,t, kWh/day, as follows:
[GRAPHIC] [TIFF OMITTED] TP21AP22.018
Where:
u = the index for each of type of electricity-consuming device
located on either (1) the interior facing side of the non-display
door or within the inside portion of the non-display door, (2) the
exterior facing side of the non-display door, or (3) any combination
of (1) and (2). For purposes of this calculation, the interior index
is represented by u = int and the exterior index is represented by u
= ext. If the electrical component is both on the interior and
exterior side of the non-display door then use u = int. For anti-
sweat heaters sited anywhere in the non-display door, 75 percent of
the total power is be attributed to u = int and 25 percent of the
total power is attributed to u = ext;
t = index for each type of electricity-consuming device with
identical rated input power;
Prated,u,t = rated input power of each component, of type
t, kW;
PTOu,t = percent time off, for device of type t, %; and
nu,t = number of devices at the rated input power of type
t, unitless.
6.3.2.3 Calculate the total electrical energy consumption for
interior and exterior power, Pnd,tot,int, kWh/day, and
Pnd,tot,ext, kWh/day, respectively, as follows:
[GRAPHIC] [TIFF OMITTED] TP21AP22.019
Where:
t = index for each type of electricity-consuming device with
identical rated input power;
Pnd,comp,int,t = the energy usage for an electricity-
consuming device sited on the internal facing side or internal to
the non-display door, of type t, kWh/day; and
Pnd,comp,ext,t = the energy usage for an electricity-
consuming device sited on the external facing side of the non-
display door, of type t, kWh/day. For anti-sweat heaters,
6.3.2.4 Calculate the total electrical energy consumption,
Pnd,tot, kWh/day, as follows:
[GRAPHIC] [TIFF OMITTED] TP21AP22.020
Where:
Pnd,tot,int = the total interior electrical energy usage
for the non-display door, of type t, kWh/day; and
Pnd,tot,ext = the total exterior electrical energy usage
for the non-display door, of type t, kWh/day.
6.3.3 Total Indirect Electricity Consumption Due to Electrical
Devices.
Calculate the additional refrigeration energy consumption due to
thermal output from electrical components associated with the non-
display door, Cnd,load, kWh/day, as follows:
[GRAPHIC] [TIFF OMITTED] TP21AP22.021
Where:
Pnd,tot,int = the total interior electrical energy
consumption for the non-display door, kWh/day; and
EER = EER of walk-in cooler or freezer, Btu/W-h. For coolers, use
EER = 12.4 Btu/(W-h). For freezers, use EER = 6.3 Btu/(W-h).
6.3.4 Total Non-Display Door Energy Consumption.
Calculate the total energy, End,tot, kWh/day, as
follows:
[GRAPHIC] [TIFF OMITTED] TP21AP22.022
Where:
End,thermal = the total daily energy consumption due to
thermal load for the non-display door, kWh/day;
Pnd,tot = the total electrical energy consumption, kWh/
day; and
Cnd,load = additional refrigeration load due to thermal
output from electrical components contained on the inside face of
the non-display door, kWh/day.
[[Page 23997]]
0
11. Revise appendix B to subpart R of part 431 to read as follows:
Appendix B to Subpart R of Part 431--Uniform Test Method for the
Measurement of R-Value of Insulation for Envelope Components of Walk-In
Coolers and Walk-In Freezers
Note: Prior to [date 180 days after publication of final rule],
representations with respect to the R-value for insulation of
envelope components of walk-in coolers and walk-in freezers,
including compliance certifications, must be based on testing
conducted in accordance with the applicable provisions of 10 CFR
part 431, subpart R, appendix B, revised as of January 1, 2022.
Beginning [date 180 days after publication of final rule],
representations with respect to R-value for insulation of envelope
components of walk-in coolers and walk-in freezers, including
compliance certifications, must be based on testing conducted in
accordance with this appendix.
0. Incorporation by Reference.
DOE incorporated by reference in Sec. 431.303 the entire
standard for ASTM C518-17. However, certain enumerated provisions of
ASTM C518-17, as set forth in section 0.1 of this appendix, are
inapplicable. To the extent there is a conflict between the terms or
provisions of a referenced industry standard and the CFR, the CFR
provisions control.
0.1 ASTM C518-17
0.1.1 Section 1 Scope, is inapplicable as specified in section
5.3.1.1 of this appendix,
0.1.2 Section 4 Significance and Use, is inapplicable as
specified in section 5.3.1.2 of this appendix,
0.1.3 Section 7.3 Specimen Conditioning, is inapplicable as
specified in section 5.3.1.3 of this appendix,
0.1.4 Section 9 Report, is inapplicable as specified in section
5.3.1.4 of this appendix,
0.1.5 Section 10 Precision and Bias, is inapplicable as
specified in section 5.3.1.5 of this appendix,
0.1.6 Section 11 Keywords, is inapplicable as specified in
section 5.3.1.6 of this appendix,
0.1.7 Annex A2 Equipment Error Analysis, is inapplicable as
specified in section 5.3.1.7 of this appendix,
0.1.8 Appendix X1 is inapplicable as specified in section
5.3.1.8 of this appendix,
0.1.9 Appendix X2 Response of Heat Flux Transducers, is
inapplicable as specified in section 5.3.1.9 of this appendix, and
0.1.10 Appendix X3 Proven Performance of a Heat Flow Apparatus,
is inapplicable as specified in section 5.3.1.10 of this appendix.
1. General.
The following sections of this appendix provide additional
instructions for testing. In cases where there is a conflict, the
language of this appendix takes highest precedence, followed by ASTM
C518-17. Any subsequent amendment to a referenced document by the
standard-setting organization will not affect the test procedure in
this appendix, unless and until the test procedure is amended by
DOE. Material is incorporated as it exists on the date of the
approval, and a notification of any change in the incorporation will
be published in the Federal Register.
2. Scope.
This appendix covers the test requirements used to measure the
R-value of non-display panels and non-display doors of a walk-in
cooler or walk-in freezer.
3. Definitions.
The definitions contained in Sec. 431.302 apply to this
appendix.
4. Additional Definitions.
4.1 Edge region means a region of the envelope component that is
wide enough to encompass any framing members. If the envelope
component contains framing members (e.g., a wood frame) then the
width of the edge region must be as wide as any framing member plus
an additional 2 in. 0.25 in.
5. Test Methods, Measurements, and Calculations.
5.1 General. Foam shall be tested after it is produced in its
final chemical form. For foam produced inside of an envelope
component (``foam-in-place''), ``final chemical form'' means the
foam is cured as intended and ready for use as a finished envelope
component. For foam produced as board stock (e.g., polystyrene),
``final chemical form'' means after extrusion and ready for assembly
into an envelope component or after assembly into an envelope
component. Foam must not include any structural members or non-foam
materials during testing in accordance with ASTM C518-17. When
preparing the specimen for test, a high-speed bandsaw or a meat
slicer are two types of recommended cutting tools. Hot wire cutters
or other heated tools shall not be used for cutting foam test
specimens.
5.2 Specimen Preparation.
5.2.1 Determining the thickness around the perimeter of the
envelope component, tp. The full thickness of an envelope component
around the perimeter, which may include facers on one or both sides,
shall be determined as follows:
5.2.1.1 At least 8 thickness measurements shall be taken around
the perimeter of the envelope component, at least 2 inches from the
edge region, and avoiding any regions with hardware or fixtures.
5.2.1.2 The average of the thickness measurements taken around
the perimeter of the envelope component shall be the thickness
around the perimeter of the envelope component, tp.
5.2.1.3 Measure and record the width, wp, and height, hp, of the
envelope component. The surface area of the envelope component, Ap,
shall be determined as follows:
[GRAPHIC] [TIFF OMITTED] TP21AP22.023
Where:
wp = width of the envelope component, in.; and
hp = height of the envelope component, in.
5.2.2. Removing the sample from the envelope component.
5.2.2.1. Determine the center of the envelope component relative
to its height and its width.
5.2.2.2. Cut a sample from the envelope component that is at
least the length and width dimensions of the heat flow meter, and
where the marked center of the sample is at least 3 inches from any
cut edge.
5.2.2.3. If the center of the envelope component contains any
non-foam components (excluding facers), additional samples may be
cut adjacent to the previous cut that is at least the length and
width dimensions of the heat flow meter and is greater than 12
inches from the edge region.
5.2.3. Determining the thickness at the center of the envelope
component, tc. The full thickness of an envelope component at the
center, which may include facers on one or both sides, shall be
determined as follows:
5.2.3.1. At least 2 thickness measurements shall be taken in
each quadrant of the cut sample removed from the envelope component
per section 5.2.2 of this appendix, for a total of at least 8
measurements.
5.2.3.2. The average of the thickness measurements of the cut
sample removed from the envelope component shall be the overall
thickness of the cut sample, tc.
5.2.3.3. Measure and record the width and height of the cut
sample removed from the envelope component. The surface area of the
cut sample removed from the envelope component, Ac., shall be
determined as follows:
[GRAPHIC] [TIFF OMITTED] TP21AP22.024
Where:
wc = width of the cut sample removed from the envelope component,
in.; and
hc = height of the cut sample removed from the envelope component,
in.
5.2.4. Determining the total thickness of the foam within the
envelope component, tfoam. The average total thickness of the foam
[[Page 23998]]
sample, without facers, shall be determined as follows:
5.2.4.1. Remove the facers on the envelope component sample,
while minimally disturbing the foam.
5.2.4.2. Measure the thickness of each facer in 4 locations for
a total of 4 measurements if 1 facer is removed, and a total of 8
measurements if 2 facers are removed. The average of all facer
measurements shall be the thickness of the facers, tfacers, in.
5.2.4.3. The average total thickness of the foam, tfoam, in.,
shall be determined as follows:
[GRAPHIC] [TIFF OMITTED] TP21AP22.025
Where:
tc = the average thickness of the center of the envelope component,
in., as determined per sections 5.2.3.1 and 5.2.3.2 of this
appendix;
Ac = the surface area of the center of the envelope component,
in\2\., as determined per section 5.2.3.3 of this appendix;
tp = the average thickness of the perimeter of the envelope
component, in., as determined per sections 5.2.1.1 and 5.2.1.2 of
this appendix;
Ap = the average thickness of the center of the envelope component,
in\2\, as determined per section 5.2.1.3 of this appendix;
tfacers = the average thickness of the facers of the envelope
component, in., as determined per section 5.2.4.2 of this appendix.
5.2.5 Cutting, measuring, and determining parallelism and
flatness of a 1-inch-thick specimen for test from the center of the
cut envelope component sample.
5.2.5.1 Cut a 1 0.1-inch-thick specimen from the
center of the cut envelope sample. The 1-inch-thick test specimen
shall be cut from the point that is equidistant from both edges of
the sample (i.e., shall be cut from the center point that would be
directly between the interior and exterior space of the walk-in).
5.2.5.2 Document through measurement or photographs with
measurement indicators that the specimen was taken from the center
of the sample.
5.2.5.3 After the 1-inch specimen has been cut, and prior to
testing, place the specimen on a flat surface and allow gravity to
determine the specimen's position on the surface. This will be side
1.
5.2.5.4 To determine the flatness of side 1, take at least nine
height measurements at equidistant positions on the specimen (i.e.,
the specimen would be divided into 9 regions and height measurements
taken at the center of each of these nine regions). Contact with the
measurement indicator shall not indent the foam surface. From the
height measurements taken, determine the least squares plane for
side 1. For each measurement location, calculate the theoretical
height from the least squares plane for side 1. Then, calculate the
difference between the measured height and the theoretical least
squares plane height at each location. The maximum difference minus
the minimum difference out of the nine measurement locations is the
flatness of side 1. For side 1 of the specimen to be considered
flat, this shall be less than or equal to 0.03 inches.
5.2.5.5 To determine the flatness of side 2, turn the specimen
over and allow gravity to determine the specimen's position on the
surface. Repeat section 5.2.5.4 to determine the flatness of side 2.
5.2.5.6 To determine the parallelism of the specimen for side 1,
calculate the theoretical height of the least squares plane at the
furthest corners (i.e., at points (0,0), (0,12), (12,0), and
(12,12)) of the 12-inch by 12-inch test specimen. The difference
between the maximum theoretical height and the minimum theoretical
height shall be less than or equal to 0.03 inches for each side in
order for side 1 to be considered parallel.
5.2.5.7 To determine the parallelism of the specimen for side 2,
repeat section
5.2.5.8 The average thickness of the test specimen, L, shall be
1 0.1-inches determined using a minimum of 18 thickness
measurements (i.e., a minimum of 9 measurements on side 1 of the
specimen and a minimum of 9 on side 2 of the specimen). This average
thickness shall be used to determine the thermal conductivity, or K-
factor.
5.3 K-factor Test. Determine the thermal conductivity, or K-
factor, of the 1-inch-thick specimen in accordance with the
specified sections of ASTM C518-17; however, the following
enumerated provisions of ASTM C518-17 are not applicable, as set
forth in section 5.3.1 of this appendix. Testing must be completed
within 24 hours of the specimen being cut for testing per section
5.2.5 of this appendix.
5.3.1 Excepted sections of ASTM C518-17.
5.3.1.1 Section 1 Scope,
5.3.1.2 Section 4 Significance and Use,
5.3.1.3 Section 7.3 Specimen Conditioning,
5.3.1.4 Section 9 Report,
5.3.1.5 Section 10 Precision and Bias,
5.3.1.6 Section 11 Keywords,
5.3.1.7 Annex A2 Equipment Error Analysis,
5.3.1.8 Appendix X1,
5.3.1.9 Appendix X2 Response of Heat Flux Transducers, and
5.3.1.10 Appendix X3 Proven Performance of a Heat Flow
Apparatus.
5.3.2 Test Conditions.
5.3.2.1 For freezer envelope components, the K-factor of the
specimen shall be determined at an average specimen temperature of
20 1 degrees Fahrenheit.
5.3.2.2 For cooler envelope components, the K-factor of the
specimen shall be determined at an average specimen temperature of
55 1 degrees Fahrenheit.
5.4 R-value Calculation.
5.4.1 For envelope components consisting of one homogeneous
layer of insulation, calculate the R-value, h-ft\2\-[deg]F/Btu, as
follows:
[GRAPHIC] [TIFF OMITTED] TP21AP22.026
Where:
tfoam = the total thickness of the foam, in., as determined in
section 5.2.4 of this appendix; and
[lgr] = K-factor, Btu-in/(h-ft\2\-[deg]F), as determined in section
5.3 of this appendix.
5.4.2 For envelope components consisting of two or more layers
of dissimilar insulating materials (excluding facers or protective
skins), determine the K-factor of each material as described in
sections 5.1 through 5.3 of this appendix. For an envelope component
with N layers of insulating material, the overall R-value shall be
calculated as follows:
[GRAPHIC] [TIFF OMITTED] TP21AP22.027
Where:
ti is the thickness of the ith material that appears in the envelope
component, inches, as determined in section 5.2.4 of this appendix;
[lgr]i is the k factor of the ith material, Btu-in/(h-ft\2\-[deg]F),
as determined in section 5.3 of this appendix; and
[[Page 23999]]
N is the total number of material layers that appears in the
envelope component.
5.4.3 K-factor test results from a test sample 1 0.1-inches in thickness may be used to determine the R-value
of envelope components with various foam thicknesses as long as the
foam throughout the panel depth is of the same final chemical form
and the test was completed at the same test conditions that the
other envelope components would be used at. For example, a K-factor
test result conducted at cooler conditions cannot be used to
determine R-value of a freezer envelope component.
0
12. Amend appendix C to subpart R of part 431 by:
0
a. Adding a note to the beginning of the appendix;
0
b. Revising sections 2.0 and 3.1.1;
0
c. Adding sections 3.1.6 and 3.1.7;
0
d. Revising sections 3.2.1 and 3.2.3;
0
e. Adding sections 3.2.6, 3.2.7, 3.2.7.1, 3.2.7.2, 3.2.7.3, and 3.2.8;
0
f. Revising sections 3.3.1 and 3.3.3;
0
g. Adding sections 3.3.3.1, 3.3.3.2, 3.3.3.3, 3.3.3.3.1, and 3.3.3.3.2;
0
h. Revising sections 3.3.7, 3.3.7.1, and 3.3.7.2;
0
i. Adding sections 3.3.7.3, 3.3.7.3.1, and 3.3.7.3.2; and
0
j. Revising section 3.4.2.1.
The additions and revisions read as follows:
Appendix C to Subpart R of Part 431--Uniform Test Method for the
Measurement of Net Capacity and AWEF of Walk-In Cooler and Walk-In
Freezer Refrigeration Systems
Note: Prior to [date 180 days after publication of final rule],
representations with respect to the energy use of refrigeration
components of walk-in coolers and walk-in freezers, including
compliance certifications, must be based on testing conducted in
accordance with the applicable provisions of this appendix as they
appeared in 10 CFR part 431, subpart R, appendix C, revised as of
January 1, 2022. Beginning [date 180 days after publication of final
rule], representations with respect to energy use of refrigeration
components of walk-in coolers and walk-in freezers, including
compliance certifications, must be based on testing conducted in
accordance with this appendix.
For any amended standards for walk-in coolers and freezers
published after January 1, 2022, manufacturers must use the results
of testing under appendix C1 of this part to determine compliance.
Representations related to energy consumption must be made in
accordance with appendix C1 of this part when determining compliance
with the relevant standard. Manufacturers may also use appendix C1
of this part to certify compliance with any amended standards prior
to the applicable compliance date for those standards.
* * * * *
2.0 Definitions.
The definitions contained in Sec. 431.302 and AHRI 1250-2009
(incorporated by reference; see Sec. 431.303) apply to this
appendix. When definitions contained in the standards DOE has
incorporated by reference are in conflict or when they conflict with
this section, the hierarchy of precedence shall be in the following
order: Sec. 431.302, AHRI 1250-2009, and then either AHRI 420-2008
(incorporated by reference; see Sec. 431.303) for unit coolers or
ASHRAE 23.1-2010 (incorporated by reference; see Sec. 431.303) for
dedicated condensing units.
The term ``unit cooler'' used in AHRI 1250-2009, AHRI 420-2008,
and this subpart shall be considered to address both ``unit
coolers'' and ``ducted fan-coil units,'' as appropriate.
3.0 * * *
3.1. * * *
3.1.1. In Table 1, Instrumentation Accuracy, refrigerant
temperature measurements shall have an accuracy of +/-0.5 [deg]F for
unit cooler in/out. When testing high-temperature refrigeration
systems, measurements used to determine temperature or water vapor
content of the air (i.e. wet bulb or dew point) shall be accurate to
within +/-0.25 [deg]F; all other temperature measurements shall be
accurate to within +/-1.0 [deg]F.
* * * * *
3.1.6. Test Operating Conditions for CO2 Unit
Coolers.
For medium-temperature CO2 unit coolers, conduct
tests using the test conditions specified in Table 17 of this
appendix. For low-temperature CO2 unit coolers, conduct
tests using the test conditions specified in Table 18 of this
appendix.
Table 17--Test Operating Conditions for Medium-Temperature CO2 Unit Coolers
--------------------------------------------------------------------------------------------------------------------------------------------------------
Unit cooler Unit cooler Liquid inlet
air entering air entering Suction dew bubble point Liquid inlet
Test description dry-bulb, relative point temp, temperature, subcooling, Compressor capacity Test objective
[deg]F humidity, % [deg]F [deg]F [deg]F
--------------------------------------------------------------------------------------------------------------------------------------------------------
Off-Cycle Power............... 35 <50 .............. .............. .............. Compressor On......... Measure fan
input power
during
compressor off
cycle.
Refrigeration Capacity, 35 <50 25 38 5 Compressor Off........ Determine Net
Ambient Condition A. Refrigeration
Capacity of
Unit Cooler.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
1. Superheat shall be set as indicated in the installation instructions. If no superheat specification is given a default superheat value of 6.5 [deg]F
shall be used.
Table 18--Test Operating Conditions for Low-Temperature CO2 Unit Coolers
--------------------------------------------------------------------------------------------------------------------------------------------------------
Unit cooler Unit cooler Liquid inlet
air entering air entering Suction dew bubble point Liquid inlet
Test description dry-bulb, relative point temp, temperature subcooling, Compressor capacity Test objective
[deg]F humidity, % [deg]F [deg]F [deg]F
--------------------------------------------------------------------------------------------------------------------------------------------------------
Off-Cycle Power............... -10 <50 .............. .............. .............. Compressor Off........ Measure fan
input power
during
compressor off
cycle.
Refrigeration Capacity, -10 <50 -20 38 5 Compressor On......... Determine Net
Ambient Condition A. Refrigeration
Capacity of
Unit Cooler.
Defrost....................... -10 <50 .............. .............. .............. Compressor Off........ Test according
to Appendix C
Section C11 of
AHRI 1250-2009.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
1. Superheat shall be set as indicated in the installation instructions. If no superheat specification is given a default superheat value of 6.5 [deg]F
shall be used.
[[Page 24000]]
3.1.7. Test Operating Conditions for High-Temperature Unit
Coolers.
For high temperature cooler unit coolers, conduct tests using
the test conditions specified in Table 19 of this appendix.
Table 19--Test Operating Conditions for High-Temperature Unit Coolers
--------------------------------------------------------------------------------------------------------------------------------------------------------
Unit cooler
Unit cooler air entering Suction dew Liquid inlet Liquid inlet
Test description air entering relative point temp, bubble point subcooling, Compressor capacity Test objective
dry-bulb, humidity, % 1 [deg]F 2 3 temperature, [deg]F
[deg]F [deg]F
--------------------------------------------------------------------------------------------------------------------------------------------------------
Off-Cycle..................... 55 55 .............. 105 9 Compressor Off........ Measure fan
input power.
Refrigeration Capacity Suction 55 55 38 105 9 Compressor On......... Determine Net
A. Refrigeration
Capacity of
Unit Cooler.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
1. The test condition tolerance (maximum permissible variation of the average value of the measurement from the specified test condition) for relative
humidity is 3%.
2. Superheat shall be set as indicated in the installation instructions. If no superheat specification is given a default superheat value of 6.5 [deg]F
shall be used.
3. Suction Dew Point shall be measured at the Unit Cooler Exit.
3.2. * * *
3.2.1. Refrigerant Temperature Measurements.
In AHRI 1250-2009 appendix C, section C3.1.6, any refrigerant
temperature measurements entering and leaving the unit cooler may
use sheathed sensors immersed in the flowing refrigerant instead of
thermometer wells. When testing a condensing unit alone, measure
refrigerant liquid temperature leaving the condensing unit using
thermometer wells as described in AHRI 1250-2009 appendix C, section
C3.1.6 or sheathed sensors immersed in the flowing refrigerant. For
all of these cases, if the refrigerant tube outer diameter is less
than \1/2\ inch, the refrigerant temperature may be measured using
the average of two temperature measuring instruments with a minimum
accuracy of 0.5 [deg]F placed on opposite sides of the
refrigerant tube surface--resulting in a total of up to 8
temperature measurement devices used for the DX Dual Instrumentation
method. In this case, the refrigerant tube shall be insulated with
1-inch thick insulation from a point 6 inches upstream of the
measurement location to a point 6 inches downstream of the
measurement location. Also, to comply with this requirement, the
unit cooler entering measurement location may be moved to a location
6 inches upstream of the expansion device and, when testing a
condensing unit alone, the entering and leaving measurement
locations may be moved to locations 6 inches from the respective
service valves.
* * * * *
3.2.3. Subcooling at Refrigerant Mass Flow Meter.
In appendix C, Section C3.4.5 of AHRI 1250-2009 (incorporated by
reference; see Sec. 431.303), and in Section 7.1.2 of ASHRAE 23.1-
2010 (incorporated by reference; see Sec. 431.303) when verifying
sub-cooling at the mass flow meters, only the sight glass and a
temperature sensor located on the tube surface under the insulation
are required. Subcooling shall be verified to be within the 3
[ordm]F requirement downstream of flow meters located in the same
chamber as a condensing unit under test and upstream of flow meters
located in the same chamber as a unit cooler under test, rather than
always downstream as indicated in AHRI 1250-2009, Section C3.4.5 or
always upstream as indicated in Section 7.1.2 of ASHRAE 23.1-2010.
If the subcooling is less than 3 [ordm]F, cool the line between the
condensing unit outlet and this location to achieve the required
subcooling. When providing such cooling while testing a matched
pair, also measure the refrigerant temperature upstream of the
location at which the line is being cooled, and increase the
temperature used to calculate unit cooler entering enthalpy by the
difference between the upstream and downstream temperatures.
* * * * *
3.2.6. Installation Instructions.
Manufacturer installation instructions or installation
instructions described in this section refer to the instructions
that come packaged with or appear on the labels applied to the unit.
This does not include online manuals or materials.
Installation Instruction Hierarchy: If a given installation
instruction provided on the label(s) applied to the unit conflicts
with the installation instructions that are shipped with the unit,
the label takes precedence. For testing of matched pairs, the
installation instructions for the dedicated condensing unit shall
take precedence. Setup shall be in accordance with the field
installation instructions (laboratory installation instructions
shall not be used). Achieving test conditions shall always take
precedence over installation instructions.
3.2.7. Refrigerant Charging and Adjustment of Superheat and
Subcooling.
All test samples shall be charged, and superheat and/or
subcooling shall be set, at Refrigeration A test conditions unless
otherwise specified in the installation instructions. If the
installation instructions give a specified range for superheat, sub-
cooling, or refrigerant pressure, the average of the range shall be
used as the refrigerant charging parameter target and the test
condition tolerance shall be 50 percent of the range.
Perform charging of near-azeotropic and zeotropic refrigerants only
with refrigerant in the liquid state. Once the correct refrigerant
charge is determined, all tests shall run until completion without
further modification.
3.2.7.1. When charging or adjusting superheat/subcooling, use
all pertinent instructions contained in the installation
instructions to achieve charging parameters within the tolerances.
However, in the event of conflicting charging information between
installation instructions, follow the installation instruction
hierarchy listed in section 3.2.6. of this appendix. Conflicting
information is defined as multiple conditions given for charge
adjustment where all conditions specified cannot be met. In the
event of conflicting information within the same set of charging
instructions (e.g., the installation instructions shipped with the
dedicated condensing unit), follow the hierarchy in Table 1 of this
section for priority. Unless the installation instructions specify a
different charging tolerance, the tolerances identified in Table 1
of this section shall be used.
Table 1--Test Condition Tolerances and Hierarchy for Refrigerant Charging and Setting of Refrigerant Conditions
----------------------------------------------------------------------------------------------------------------
Fixed orifice Expansion valve
-----------------------------------------------------------------------------------------------
Priority Parameter with Parameter with
installation Tolerance installation instruction Tolerance
instruction target target
----------------------------------------------------------------------------------------------------------------
1............... Super-heat............. 2.0 Sub-cooling.............. 10% of the Target
[deg]F. Value; No less than
0.5
[deg]F, No more than
2.0
[deg]F.
[[Page 24001]]
2............... High Side Pressure or 4.0 High Side Pressure or 4.0 psi or
Saturation Temperature. psi or 1.0
minus>1.0 [deg]F. [deg]F.
3............... Low Side Pressure or 2.0 Super-heat............... 2.0
Saturation Temperature. psi or 0.8 [deg]F.
4............... Low Side Temperature... 2.0 Low Side Pressure or 2.0 psi or
[deg]F. Saturation Temperature. 0.8
[deg]F.
5............... High Side Temperature.. 2.0 Approach Temperature..... 1.0
[deg]F. [deg]F.
6............... Charge Weight.......... 2.0 oz Charge Weight............ 0.5% or 1.0 oz,
whichever is greater.
----------------------------------------------------------------------------------------------------------------
3.2.7.2. Dedicated Condensing Unit. If the Dedicated Condensing
Unit includes a receiver and the subcooling target leaving the
condensing unit provided in installation instructions cannot be met
without fully filling the receiver, the subcooling target shall be
ignored. Likewise, if the Dedicated Condensing unit does not include
a receiver and the subcooling target leaving the condensing unit
cannot be met without the unit cycling off on high pressure, the
subcooling target can be ignored. Also, if no instructions for
charging or for setting subcooling leaving the condensing unit are
provided in the installation instructions, the refrigeration system
shall be set up with a charge quantity and/or exit subcooling such
that the unit operates during testing without shutdown (e.g., on a
high-pressure switch) and operation of the unit is otherwise
consistent with the requirements of the test procedure of this
appendix and the installation instructions.
3.2.7.3. Unit Cooler. Use the shipped expansion device for
testing. Otherwise, use the expansion device specified in the
installation instructions. If the installation instructions specify
multiple options for the expansion device, any specified expansion
device may be used. The supplied expansion device shall be adjusted
until either the superheat target is met, or the device reaches the
end of its adjustable range. In the event the device reaches the end
of its adjustable range and the super heat target is not met, test
with the adjustment at the end of its range providing the closest
match to the superheat target, and the test condition tolerance for
super heat target shall be ignored. The measured superheat is not
subject to a test operating tolerance. However, if the evaporator
exit condition is used to determine capacity using the DX dual-
instrumentation method or the refrigerant enthalpy method,
individual superheat value measurements may not be equal to or less
than zero. If this occurs, or if the operating tolerances of
measurements affected by expansion device fluctuation are exceeded,
the expansion device shall be replaced, operated at an average
superheat value higher than the target, or both, in order to avoid
individual superheat value measurements less than zero and/or to
meet the required operating tolerances.
3.2.8. Chamber Conditioning using the Unit Under Test.
In appendix C, Section C6.2 of AHRI 1250-2009, for applicable
system configurations (matched pairs, single-packaged refrigeration
systems, and standalone unit coolers), the unit under test may be
used to aid in achieving the required test chamber conditions prior
to beginning any steady state test. However, the unit under test
must be inspected and confirmed to be free from frost before
initiating steady state testing.
3.3. * * *
3.3.1. For unit coolers tested alone, use test procedures
described in AHRI 1250-2009 for testing unit coolers for use in mix-
match system ratings, except that for the test conditions in Tables
15 and 16 of this appendix, use the Suction A saturation condition
test points only. Also for unit coolers tested alone, other than
high-temperature unit coolers, use the calculations in section 7.9
to determine AWEF and net capacity described in AHRI 1250-2009 for
unit coolers matched to parallel rack systems.
* * * * *
3.3.3. Evaporator Fan Power.
3.3.3.1. Ducted Evaporator Air.
For ducted fan-coil units with ducted evaporator air, or that
can be installed with or without ducted evaporator air: Connect
ductwork on both the inlet and outlet connections and determine
external static pressure as described in ASHRAE 37-2009
(incorporated by reference; see Sec. 431.303), Sections 6.4 and
6.5. Use pressure measurement instrumentation as described in ASHRAE
37-2009, Section 5.3.2. Test at the fan speed specified in
manufacturer installation instructions--if there is more than one
fan speed setting and the installation instructions do not specify
which speed to use, test at the highest speed. Conduct tests with
the external static pressure equal to 50 percent of the maximum
external static pressure allowed by the manufacturer for system
installation within a tolerance of -0.00/+0.05 in. wc. Set the
external static pressure by symmetrically restricting the outlet of
the test duct. Alternatively, if using the indoor air enthalpy
method to measure capacity, set external static pressure by
adjusting the fan of the airflow measurement apparatus. In case of
conflict, these requirements for setting evaporator airflow take
precedence over airflow values specified in manufacturer
installation instructions or product literature.
3.3.3.2. Unit Coolers or Single-Packaged Systems that are not
High-Temperature Refrigeration Systems.
Use appendix C, Section C10 of AHRI 1250-2009 for off-cycle
evaporator fan testing, with the exception that evaporator fan
controls using periodic stir cycles shall be adjusted so that the
greater of a 50% duty cycle (rather than a 25% duty cycle) or the
manufacturer default is used for measuring off-cycle fan energy. For
adjustable-speed controls, the greater of 50% fan speed (rather than
25% fan speed) or the manufacturer's default fan speed shall be used
for measuring off-cycle fan energy. Also, a two-speed or multi-speed
fan control may be used as the qualifying evaporator fan control.
For such a control, a fan speed no less than 50% of the speed used
in the maximum capacity tests shall be used for measuring off-cycle
fan energy.
3.3.3.3. High-Temperature Refrigeration Systems.
3.3.3.3.1. The evaporator fan power consumption shall be
measured in accordance with the requirements in Section C3.5 of AHRI
1250-2009. This measurement shall be made with the fan operating at
full speed, either measuring unit cooler or total system power input
upon the completion of the steady state test when the compressor and
the condenser fan of the walk-in system are turned off, or by
submetered measurement of the evaporator fan power during the steady
state test.
Section C3.5 of AHRI 1250-2009 is revised to read:
Evaporator Fan Power Measurement.
The following shall be measured and recorded during a fan power
test.
EFcomp,on Total electrical power input to fan motor(s) of
Unit Cooler, W
FS Fan speed(s), rpm
N Number of motors
Pb Barometric pressure, in. Hg
Tdb Dry-bulb temperature of air at inlet, [deg]F
[[Page 24002]]
Twb Wet-bulb temperature of air at inlet, [deg]F
V Voltage of each phase
For a given motor winding configuration, the total power input
shall be measured at the highest nameplate voltage. For three-phase
power, voltage imbalance shall be no more than 2%.
3.3.3.3.2. Evaporator fan power for the off-cycle is equal to
the on-cycle evaporator fan power with a run time of ten percent of
the off-cycle time.
EFcomp,off = 0.1 x EFcomp,on
* * * * *
3.3.7. Calculations for Unit Coolers Tested Alone.
3.3.7.1. Unit Coolers that are not High-Temperature Unit
Coolers.
Calculate the AWEF and net capacity using the calculations in
AHRI 1250-2009, Section 7.9.
3.3.7.2. High-Temperature Unit Coolers.
Calculate AWEF on the basis that walk-in box load is equal to
half of the system net capacity, without variation according to high
and low load periods, and with EER set according to tested
evaporator capacity, as follows:
The net capacity, qmix,evap, is determined from the test data
for the unit cooler at the 38 [deg]F suction dewpoint.
[GRAPHIC] [TIFF OMITTED] TP21AP22.028
[GRAPHIC] [TIFF OMITTED] TP21AP22.029
Where:
BL is the non-equipment-related box load;
LF is the load factor; and
Other symbols are as defined in Section 8 of AHRI 1250-2009.
3.3.7.3. If the unit cooler has variable-speed evaporator fans
that vary fan speed in response to load, then:
3.3.7.3.1. When testing to certify compliance with the energy
conservation standards in Sec. 431.306, fans shall operate at full
speed during on-cycle operation. Do not conduct the calculations in
AHRI 1250-2009, Section 7.9.3. Instead, use AHRI 1250-2009, Section
7.9.2 to determine the system's AWEF.
3.3.7.3.2. When calculating the benefit for the inclusion of
variable-speed evaporator fans that modulate fan speed in response
to load for the purpose of making representations of efficiency, use
AHRI 1250-2009, Section 7.9.3 to determine the system A WEF.
3.4. * * *
3.4.2. * * *
3.4.2.1. For calculating enthalpy leaving the unit cooler to
calculate gross capacity, (a) the saturated refrigerant temperature
(dew point) at the unit cooler coil exit, Tevap, shall be
25 [deg]F for medium-temperature systems (coolers) and -20 [deg]F
for low-temperature systems (freezers), and (b) the refrigerant
temperature at the unit cooler exit shall be 35 [deg]F for medium-
temperature systems (coolers) and -14 [deg]F for low-temperature
systems (freezers). For calculating gross capacity, the measured
enthalpy at the condensing unit exit shall be used as the enthalpy
entering the unit cooler. The temperature measurement requirements
of appendix C, Section C3.1.6 of AHRI 1250-2009 and modified by
section 3.2.1 of this appendix shall apply only to the condensing
unit exit rather than to the unit cooler inlet and outlet, and they
shall be applied for two measurements when using the DX Dual
Instrumentation test method.
* * * * *
0
13. Add appendix C1 to subpart R of part 431 to read as follows:
Appendix C1 to Subpart R of Part 431--Uniform Test Method for the
Measurement of Net Capacity and AWEF of Walk-In Cooler and Walk-In
Freezer Refrigeration Systems
Note: Prior to [date 180 days after publication of final rule],
representations with respect to the energy use of refrigeration
components of walk-in coolers and walk-in freezers, including
compliance certifications, must be based on testing conducted in
accordance with the applicable provisions for 10 CFR part 431,
subpart R, appendix C,
[[Page 24003]]
revised as of January 1, 2022. Beginning [date 180 days after
publication of final rule], representations with respect to energy
use of refrigeration components of walk-in coolers and walk-in
freezers, including compliance certifications, must be based on
testing conducted in accordance with appendix C of this subpart.
For any amended standards for walk-in coolers and walk-in
freezers published after January 1, 2022, manufacturers must use the
results of testing under this appendix to determine compliance.
Representations related to energy consumption must be made in
accordance with this appendix when determining compliance with the
relevant standard. Manufacturers may also use this appendix to
certify compliance with any amended standards prior to the
applicable compliance date for those standards.
1. Incorporation by Reference
DOE incorporated by reference in Sec. 431.303, the entire
standards for AHRI 1250-2020, ANSI/ASHRAE 16, and ANSI/ASHRAE 37.
However, certain enumerated provisions of these standards, as set
forth in sections 1.1, 1.2, and 1.3 of this appendix are
inapplicable. To the extent there is a conflict between the terms or
provisions of a referenced industry standard and the CFR, the CFR
provisions control. To the extent there is a conflict between the
terms or provisions of AHRI 1250-2020, ANSI/ASHRAE 16, and ANSI/
ASHRAE 37, the AHRI 1250-2020 provisions control.
1.1 AHRI 1250-2020
1.1.1 Section 1 Purpose, is inapplicable as specified in section
4.1.1 of this appendix.
1.1.2 Section 2 Scope, is inapplicable as specified in section
4.1.2 of this appendix.
1.1.3 Section 9 Minimum Data Requirements for Published Rating,
is inapplicable as specified in section 4.1.3 of this appendix.
1.1.4 Section 10 Marking and Nameplate Data, is inapplicable as
specified in section 4.1.4 of this appendix.
1.1.5 Section 11 Conformance Conditions, is inapplicable as
specified in section 4.1.5 of this appendix.
1.2 ANSI/ASHRAE 16
1.2.1 Section 1 Purpose, is inapplicable as specified in section
4.2.1 of this appendix.
1.2.2 Section 2 Scope, is inapplicable as specified in section
4.2.2 of this appendix.
1.2.3 Section 4 Classifications, is inapplicable as specified in
section 4.2.3 of this appendix.
1.2.4 Normative Appendices E-M, are inapplicable as specified in
section 4.2.4 of this appendix.
1.2.5 Informative Appendices N-R, are inapplicable as specified
in section 4.2.5 of this appendix.
1.3 ANSI/ASHRAE 37
1.3.1 Section 1 Purpose, is inapplicable as specified in section
4.3.1 of this appendix.
1.3.2 Section 2 Scope, is inapplicable as specified in section
4.3.2 of this appendix.
1.3.3 Section 4 Classifications, is inapplicable as specified in
section 4.3.3 of this appendix.
1.3.4 Informative Appendix A Classifications of Unitary Air-
conditioners and Heat Pumps, is inapplicable as specified in section
4.3.4 of this appendix.
2. Scope.
This appendix covers the test requirements used to determine the
net capacity and the AWEF of the refrigeration system of a walk-in
cooler or walk-in freezer.
3. Definitions.
3.1. Applicable Definitions.
The definitions contained in Sec. 431.302, AHRI 1250-2020,
ANSI/ASHRAE 37, and ANSI/ASHRAE 16 apply to this appendix. When
definitions in standards incorporated by reference are in conflict
or when they conflict with this section, the hierarchy of precedence
shall be in the following order: Sec. 431.302, AHRI 1250-2020, and
then either ANSI/ASHRAE 37 or ANSI/ASHRAE 16.
The term ``unit cooler'' used in AHRI 1250-2020 and this subpart
shall be considered to address both ``unit coolers'' and ``ducted
fan-coil units,'' as appropriate.
3.2. Additional Definitions.
3.2.1. Digital Compressor means a compressor that uses
mechanical means for disengaging active compression on a cyclic
basis to provide a reduced average refrigerant flow rate in response
to a control system input signal.
3.2.2. Displacement Ratio, applicable to staged positive
displacement compressor systems, means the swept volume rate, e.g.,
in cubic centimeters per second, of a given stage, divided by the
swept volume rate at full capacity.
3.2.3. Duty Cycle, applicable to digital compressors, means the
fraction of time that the compressor is engaged and actively
compressing refrigerant.
3.2.4. Maximum Speed, applicable to variable-speed compressors,
means the maximum speed at which the compressor will operate under
the control of the dedicated condensing system control system for
extended periods of time, i.e., not including short-duration boost-
mode operation.
3.2.5. Minimum Speed, applicable to variable-speed compressors,
means the minimum compressor speed at which the compressor will
operate under the control of the dedicated condensing system control
system.
3.2.6. Multiple-Capacity, applicable for describing a
refrigeration system, indicates that it has three or more stages
(levels) of capacity.
3.2.7. Speed Ratio, applicable to variable-speed compressors,
means the ratio of operating speed to the maximum speed.
4. Test Methods, Measurements, and Calculations.
Determine the Annual Walk-in Energy Factor (AWEF) and net
capacity of walk-in cooler and walk-in freezer refrigeration systems
by conducting the test procedure set forth in AHRI 1250-2020, with
the modifications to that test procedure provided in this section.
However, certain sections of AHRI 1250-2020, ANSI/ASHRAE 37, and
ANSI/ASHRAE 16 are not applicable, as set forth in sections 4.1,
4.2, and 4.3 of this appendix. Round AWEF measurements to the
nearest 0.05 Btu/Wh. Round net capacity measurements as indicated in
Table 1 of this appendix.
Table 1--Rounding of Refrigeration System Net Capacity
------------------------------------------------------------------------
Rounding
Net capacity range, Btu/h multiple, Btu/
h
------------------------------------------------------------------------
<20,000................................................. 100
>=20,000 and <38,000.................................... 200
>=38,000 and <65,000.................................... 500
>=65,000................................................ 1,000
------------------------------------------------------------------------
The following sections of this appendix provide additional
instructions for testing. In cases where there is a conflict, the
language of this appendix takes highest precedence, followed by AHRI
1250-2020, then ANSI/ASHRAE 37 or ANSI/ASHRAE 16. Any subsequent
amendment to a referenced document by the standard-setting
organization will not affect the test procedure in this appendix,
unless and until the test procedure is amended by DOE. Material is
incorporated as it exists on the date of the approval, and a notice
of any change in the incorporation will be published in the Federal
Register.
4.1 Excepted sections of AHRI 1250-2020.
(a) Section 1 Purpose,
(b) Section 2 Scope,
(c) Section 9 Minimum Data Requirements for Published Ratings,
(d) Section 10 Marking and Nameplate Data, and
(e) Section 11 Conformance Conditions.
4.2 Excepted sections of ANSI/ASHRAE 16.
(a) Section 1 Purpose,
(b) Section 2 Scope,
(c) Section 4 Classifications,
(d) Normative Appendices E-M,
(e) Informative Appendices N-R.
4.3 Excepted sections of ANSI/ASHRAE 37.
(a) Section 1 Purpose,
(b) Section 2 Scope,
(c) Section 4 Classifications,
(d) Informative Appendix A Classifications of Unitary Air-
conditioners and Heat Pumps.
4.4. Instrumentation Accuracy and Test Tolerances.
Use measuring instruments as described in Section 4.1 of AHRI
1250-2020, with the following additional requirement.
4.4.1. Electrical Energy Input measured in Wh with a minimum
accuracy of 0.5% of reading (for Off-Cycle tests per
footnote 5 of Table C3 in Section C3.6.2 of AHRI 1250-2020).
4.5. Test Operating Conditions.
Test conditions used to determine AWEF shall be as specified in
Tables 4 through 17 of AHRI 1250-2020. Tables 7 and 11 of AHRI 1250-
2020, labeled to apply to variable-speed outdoor matched-pair
refrigeration systems, shall also be used for testing variable-
capacity single-packaged outdoor refrigeration systems, and also for
testing multiple-capacity matched-pair or single-packaged outdoor
refrigeration systems. Test conditions used to determine AWEF for
refrigeration systems not specifically identified in AHRI 1250-2020
are as enumerated in sections 4.5.1 through 4.5.6 of this appendix.
[[Page 24004]]
4.5.1 Test Operating Conditions for High-Temperature
Refrigeration Systems.
For fixed-capacity high-temperature matched-pair or single-
packaged refrigeration systems with indoor condensing units, conduct
tests using the test conditions specified in Table 2 of this
appendix. For fixed-capacity high-temperature matched-pair or
single-packaged refrigeration systems with outdoor condensing units,
conduct tests using the test conditions specified in Table 3 of this
appendix. For high-temperature unit coolers tested alone, conduct
tests using the test conditions specified in Table 4 of this
appendix.
Table 2--Test Operating Conditions for Fixed-Capacity High-Temperature Indoor Matched Pair or Single-Packaged Refrigeration Systems
--------------------------------------------------------------------------------------------------------------------------------------------------------
Unit cooler
Unit cooler air entering Condenser air Condenser air
Test description air entering relative entering dry- entering wet- Compressor status Test objective
dry-bulb, humidity, % bulb, [deg]F bulb, [deg]F
[deg]F \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Off-Cycle Power.................... 55 55 .............. .............. Compressor Off............. Measure total input
wattage during
compressor off cycle,
(Ecu,off +
EFcomp,off) \2\.
Refrigeration Capacity A........... 55 55 90 75,\3\ 65 \4\ Compressor On.............. Determine Net
Refrigeration
Capacity of Unit
Cooler, input power,
and EER at Test
Condition.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
1 The test condition tolerance (maximum permissible variation of the average value of the measurement from the specified test condition) for relative
humidity is 3%.
2 Measure off-cycle power as described in Sections C3 and C4.2 of AHRI 1250-2020.
3 Required only for evaporative condensing units (e.g., incorporates a slinger ring).
4 Maximum allowable value for Single-Packaged Systems that do not use evaporative Dedicated Condensing Units, where all or part of the equipment is
located in the outdoor room.
Table 3--Test Operating Conditions for Fixed-Capacity High-Temperature Outdoor Matched-Pair or Single-Packaged Refrigeration Systems
--------------------------------------------------------------------------------------------------------------------------------------------------------
Unit cooler
Unit cooler air entering Condenser air Condenser air
Test description air entering relative entering dry- entering wet- Compressor status Test objective
dry-bulb, humidity, % bulb, [deg]F bulb, [deg]F
[deg]F \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Refrigeration Capacity A........... 55 55 95 75,\3\ 68 \4\ Compressor On.............. Determine Net
Refrigeration
Capacity of Unit
Cooler, input power,
and EER at Test
Condition.
Off-Cycle Power, Capacity A........ 55 55 95 75,\3\ 68 \4\ Compressor Off............. Measure total input
wattage during
compressor off cycle,
(Ecu,off +
EFcomp,off) \2\.
Refrigeration Capacity B........... 55 55 59 54,\3\ 46 \4\ Compressor On.............. Determine Net
Refrigeration
Capacity of Unit
Cooler and system
input power at
moderate condition.
Off-Cycle Power, Capacity B........ 55 55 59 54,\3\ 46 \4\ Compressor Off............. Measure total input
wattage during
compressor off cycle,
(Ecu,off +
EFcomp,off) \2\.
Refrigeration Capacity C........... 55 55 35 34,\3\ 29 \4\ Compressor On.............. Determine Net
Refrigeration
Capacity of Unit
Cooler and system
input power at cold
condition.
Off-Cycle Power, Capacity C........ 55 55 35 34,\3\ 29 \4\ Compressor Off............. Measure total input
wattage during
compressor off cycle,
(Ecu,off +
EFcomp,off) \2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
1 The test condition tolerance (maximum permissible variation of the average value of the measurement from the specified test condition) for relative
humidity is 3%.
2 Measure off-cycle power as described in Sections C3 and C4.2 of AHRI 1250-2020.
3 Required only for evaporative condensing units (e.g., incorporates a slinger ring).
4 Maximum allowable value for Single-Packaged Systems that do not use evaporative Dedicated Condensing Units, where all or part of the equipment is
located in the outdoor room.
Table 4--Test Operating Conditions for High-Temperature Unit Coolers
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Unit cooler
Unit cooler air entering Suction dew Liquid inlet Liquid inlet
Test description air entering relative point temp, bubble point subcooling, Compressor status Test objective
dry-bulb, humidity, % [deg]F \3\ \4\ temperature, [deg]F
[deg]F \1\ [deg]F
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Off-Cycle............................. 55 55 .............. 105 9 Compressor Off................ Measure unit cooler input wattage during
compressor off cycle, EF \2\.
Refrigeration Capacity................ 55 55 38 105 9 Compressor On................. Determine Net Refrigeration Capacity of
Unit Cooler, input power, and EER at
Test Condition.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
1 The test condition tolerance (maximum permissible variation of the average value of the measurement from the specified test condition) for relative humidity is 3%.
2 Measure off-cycle power as described in Sections C3 and C4.2 of AHRI 1250-2020.
3 Superheat shall be set as indicated in the installation instructions. If no superheat specification is given a default superheat value of 6.5 [deg]F shall be used.
4 Suction Dew Point shall be measured at the Unit Cooler Exit.
4.5.2 Test Operating Conditions for CO2 Unit Coolers.
For medium-temperature CO2 Unit Coolers, conduct
tests using the test conditions specified in Table 5 of this
appendix. For low-temperature CO2 Unit Coolers, conduct
tests using the test conditions specified in Table 6 of this
appendix.
[[Page 24005]]
Table 5--Test Operating Conditions for Medium-Temperature CO2 Unit Coolers \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Unit cooler Unit cooler Liquid inlet
air entering air entering Suction dew bubble point Liquid inlet Compressor operating
Test title dry-bulb, relative point temp,\3\ temperature, subcooling, mode Test objective
[deg]F humidity, % [deg]F [deg]F [deg]F
--------------------------------------------------------------------------------------------------------------------------------------------------------
Off-Cycle Power............... 35 <50 .............. .............. .............. Compressor On......... Measure unit
cooler input
wattage during
compressor off
cycle,
EBFcomp,off.\2\
Refrigeration Capacity, 35 <50 25 38 5 Compressor Off........ Determine Net
Ambient Condition A. Refrigeration
Capacity of
Unit Cooler,
qmix,rack.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
\1\ Superheat shall be set as indicated in the installation instructions. If no superheat specification is given a default superheat value of 6.5 [deg]F
shall be used.
\2\ Measure off-cycle power as described in Sections C3 and C4.2 of AHRI 1250-2020.
\3\ Suction Dew Point shall be measured at the Unit Cooler Exit conditions.
Table 6--Test Operating Conditions for Low-Temperature CO2 Unit Coolers \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Unit cooler Unit cooler Liquid inlet
air entering air entering Suction dew bubble point Liquid inlet Compressor operating
Test Title dry-bulb, relative point temp,\3\ temperature, subcooling, mode Test objective
[deg]F humidity, % [deg]F [deg]F [deg]F
--------------------------------------------------------------------------------------------------------------------------------------------------------
Off-Cycle Power............... -10 <50 .............. .............. .............. Compressor Off........ Measure unit
cooler input
wattage during
compressor off
cycle,
EBFcomp,off.\2\
Refrigeration Capacity, -10 <50 -20 38 5 Compressor On......... Determine Net
Ambient Condition A. Refrigeration
Capacity of
Unit Cooler,
qmix,rack.
Defrost....................... -10 <50 .............. .............. .............. Compressor Off........ Test according
to Appendix C
Section C10 of
AHRI 1250-2020,
DBF,QBDF.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
\1\ Superheat shall be set as indicated in the installation instructions. If no superheat specification is given a default superheat value of 6.5 [deg]F
shall be used.
\2\ Measure off-cycle power as described in Sections C3 and C4.2 of AHRI 1250-2020.
\3\ Suction Dew Point shall be measured at the Unit Cooler Exit conditions.
4.5.3 Test Operating Conditions for Two-Capacity Condensing
Units Tested Alone.
For two-capacity medium-temperature outdoor condensing units
tested alone, conduct tests using the test conditions specified in
Table 7 of this appendix. For two-capacity medium-temperature indoor
condensing units tested alone, conduct tests using the test
conditions specified in Table 8 of this appendix. For two-capacity
low-temperature outdoor condensing units tested alone, conduct tests
using the test conditions specified in Table 9 of this appendix. For
two-capacity low-temperature indoor condensing units tested alone,
conduct tests using the test conditions specified in Table 10 of
this appendix.
Table 7--Test Operating Conditions for Two-Capacity Medium-Temperature Outdoor Dedicated Condensing Units
--------------------------------------------------------------------------------------------------------------------------------------------------------
Condenser air
Suction dew point, Return gas, Condenser air entering wet-
Test description [deg]F [deg]F entering dry- bulb, [deg]F Compressor status
bulb, [deg]F \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Capacity, Condition A, Low Capacity.. Unit Cooler Low Fan: \2\ 49 95 75 Low Capacity, k=1.
24.5. 46
Unit Cooler High Fan:
\2\ 25.5.
Capacity, Condition A, High Capacity. 23...................... 41 95 75 High Capacity, k=2.
Off Cycle, Condition A............... ........................ .............. 95 75 Off.
Capacity, Condition B, Low Capacity.. Unit Cooler Low Fan: \2\ 47 59 54 Low Capacity, k=1.
24.5. 45
Unit Cooler High Fan:
\2\ 25.5.
Capacity, Condition B, High Capacity. 23...................... .............. 59 54 High Capacity, k=2.
Off Cycle, Condition B............... ........................ .............. 59 54 Off.
Capacity, Condition C, Low Capacity.. Unit Cooler Low Fan: \2\ 41 35 34 Low Capacity, k=1.
22.5. 41
Unit Cooler High Fan:
\2\ 25.5.
Capacity, Condition C, High Capacity. 23...................... 41 35 34 High Capacity, k=2.
Off Cycle, Condition C............... ........................ .............. 35 34 Off.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
\1\ Required only for evaporative condensing units (e.g., incorporates a slinger ring).
\2\ When Staged compressor displacement ratio for low capacity is 65% or less, use the Unit Cooler Low Fan condition, otherwise use the Unit cooler High
Fan condition.
[[Page 24006]]
Table 8--Test Operating Conditions for Two-Capacity Medium-Temperature Indoor Dedicated Condensing Units
--------------------------------------------------------------------------------------------------------------------------------------------------------
Condenser air
Suction dew point, Return gas, Condenser air entering wet-
Test description [deg]F [deg]F entering dry- bulb, [deg]F Compressor status
bulb, [deg]F \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Capacity, Condition A, Low Capacity.. Unit Cooler Low Fan: \2\ 49 90 75 Low Capacity, k=1.
24.5. 46
Unit Cooler High Fan:
\2\ 25.5.
Capacity, Condition A, High Capacity. 23...................... 41 90 75 High Capacity, k=2.
Off Cycle, Condition A............... ........................ .............. 90 75 Off.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
\1\ Required only for evaporative condensing units (e.g., incorporates a slinger ring).
\2\ When staged compressor displacement ratio for low capacity is 65% or less, use the Unit Cooler Low Fan condition, otherwise use the Unit cooler High
Fan condition.
Table 9--Test Operating Conditions for Two-Capacity Low-Temperature Outdoor Dedicated Condensing Units
--------------------------------------------------------------------------------------------------------------------------------------------------------
Condenser air
Return gas, Condenser air entering wet-
Test title Suction dew point, [deg]F [deg]F entering dry- bulb, [deg]F Compressor operating mode
bulb, [deg]F \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Capacity, Condition A, Low Capacity...... Unit Cooler Low Fan: \2\ -20.5.. 21 95 75 Low Capacity, k=1.
Unit Cooler High Fan: \2\ -19.5. 13
Capacity, Condition A, High Capacity..... -22............................. 5 95 75 High Capacity, k=2.
Off Cycle, Condition A................... ................................ .............. 95 75 Compressor Off.
Capacity, Condition B, Low Capacity...... Unit Cooler Low Fan: \2\ -20.5.. 19 59 54 Low Capacity, k=1.
Unit Cooler High Fan: \2\ -19.5. 13
Capacity, Condition B, High Capacity..... -22............................. 5 59 54 High Capacity, k=2.
Off Cycle, Condition B................... ................................ .............. 59 54 Compressor Off.
Capacity, Condition C, Low Capacity...... Unit Cooler Low Fan: \2\ -20.5.. 17 35 34 Low Capacity, k=1.
Unit Cooler High Fan: \2\ -19.5. 12
Capacity, Condition C, High Capacity..... -22............................. 5 35 34 Maximum Capacity, k=2.
Off Cycle, Condition C................... ................................ .............. 35 34 Compressor Off.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
\1\ Required only for evaporative condensing units (e.g., incorporates a slinger ring).
\2\ When staged compressor displacement ratio for low capacity is 65% or less, use the Unit Cooler Low Fan condition, otherwise use the Unit cooler High
Fan condition.
Table 10--Test Operating Conditions for Two-Capacity Low-Temperature Indoor Dedicated Condensing Units
--------------------------------------------------------------------------------------------------------------------------------------------------------
Condenser air
Suction dew point, Return gas, Condenser air entering wet-
Test title [deg]F [deg]F entering dry- bulb, [deg]F Compressor operating mode
bulb, [deg]F \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Capacity, Condition A, Low Capacity.. Unit Cooler Low Fan: \2\ 21 90 75 Low Capacity, k=1.
-20.5. 13
Unit Cooler High Fan:
\2\-19.5.
Capacity, Condition A, High Capacity. -22..................... 5 90 75 High Capacity, k=2.
Off Cycle, Condition A............... ........................ .............. 90 75 Compressor Off.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
\1\ Required only for evaporative condensing units (e.g., incorporates a slinger ring).
\2\ When staged compressor displacement ratio for low capacity is 65% or less, use the Unit Cooler Low Fan condition, otherwise use the Unit cooler High
Fan condition.
4.5.4 Test Operating Conditions for Variable- or Multiple-
Capacity Condensing Units Tested Alone.
For variable-capacity or multiple-capacity outdoor medium-
temperature condensing units tested alone, conduct tests using the
test conditions specified in Table 11 of this appendix. For
variable-capacity or multiple-capacity indoor medium-temperature
condensing units tested alone, conduct tests using the test
conditions specified in Table 12 of this appendix. For variable-
capacity or multiple-capacity outdoor low-temperature condensing
units tested alone, conduct tests using the test conditions
specified in Table 13 of this appendix. For variable-capacity or
multiple-capacity indoor low-temperature condensing units tested
alone, conduct tests using the test conditions specified in Table 14
of this appendix.
[[Page 24007]]
Table 11--Test Operating Conditions for Variable- or Multiple-Capacity Medium-Temperature Outdoor Dedicated Condensing Units
--------------------------------------------------------------------------------------------------------------------------------------------------------
Condenser air
Suction dew point, Return gas, Condenser air entering wet-
Test description [deg]F [deg]F entering dry- bulb, [deg]F Compressor status
bulb, [deg]F \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Capacity, Condition A, Minimum 26...................... 56 95 75 Minimum Capacity, k=1.
Capacity.
Capacity, Condition A, Intermediate Unit Cooler Low Fan: \2\ 44 95 75 Intermediate Capacity, k=i.
Capacity. 22.5. 46
Unit Cooler High Fan:
\2\ 25.5.
Capacity, Condition A, Maximum 23...................... 41 95 75 Maximum Capacity, k=2.
Capacity.
Off Cycle, Condition A............... ........................ .............. 95 75 Off.
Capacity, Condition B, Minimum 26...................... 51 59 54 Minimum Capacity, k=1.
Capacity.
Capacity, Condition B, Intermediate Unit Cooler Low Fan: \2\ 44 59 54 Intermediate Capacity, k=i.
Capacity. 22.5. 45
Unit Cooler High Fan:
\2\ 25.5.
Capacity, Condition B, Maximum 23...................... 41 59 54 Maximum Capacity, k=2.
Capacity.
Off Cycle, Condition B............... ........................ .............. 59 54 Off.
Capacity, Condition C, Minimum 26...................... 41 35 34 Minimum Capacity, k=1.
Capacity.
Capacity, Condition C, Intermediate Unit Cooler Low Fan: \2\ 41 35 34 Intermediate Capacity, k=i.
Capacity. 22.5. 41
Unit Cooler High Fan:
\2\ 25.5.
Capacity, Condition C, Maximum 23...................... 41 35 34 Maximum Capacity, k=2.
Capacity.
Off Cycle, Condition C............... ........................ .............. 35 34 Off
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
\1\ Required only for evaporative condensing units (e.g., incorporates a slinger ring).
\2\ When Digital Compressor duty cycle, variable-speed speed ratio, or staged compressor displacement ratio for intermediate capacity is 65% or less,
use the Unit Cooler Low Fan condition, otherwise use the Unit cooler High Fan condition.
Table 12--Test Operating Conditions for Variable- or Multiple-Capacity Medium-Temperature Indoor Dedicated Condensing Units
--------------------------------------------------------------------------------------------------------------------------------------------------------
Condenser air
Suction dew point, Return gas, Condenser air entering wet-
Test description [deg]F [deg]F entering dry- bulb, [deg]F Compressor status
bulb, [deg]F \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Capacity, Condition A, Minimum 26...................... 56 90 75 Minimum Capacity, k=1.
Capacity.
Capacity, Condition A, Intermediate Unit Cooler Low Fan: \2\ 44 90 75 Intermediate Capacity, k=i,
Capacity. 22.5. 46
Unit Cooler High Fan:
\2\ 25.5.
Capacity, Condition A, Maximum 23...................... 41 90 75 Maximum Capacity, k=2.
Capacity.
Off Cycle, Condition A............... ........................ .............. 90 75 Off.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
\1\ Required only for evaporative condensing units (e.g., incorporates a slinger ring).
\2\ When Digital Compressor duty cycle, variable-speed speed ratio, or staged compressor displacement ratio for intermediate capacity is 65% or less,
use the Unit Cooler Low Fan condition, otherwise use the Unit cooler High Fan condition.
Table 13--Test Operating Conditions for Variable- or Multiple-Capacity Low-Temperature Outdoor Dedicated Condensing Units
--------------------------------------------------------------------------------------------------------------------------------------------------------
Condenser air
Suction dew point, Return gas, Condenser air entering wet-
Test title [deg]F [deg]F entering dry- bulb, [deg]F Compressor operating mode
bulb, [deg]F \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Capacity, Condition A, Minimum -19..................... 32 95 75 Minimum Capacity, k=1.
Capacity.
Capacity, Condition A, Intermediate Unit Cooler Low Fan: \2\ 13 95 75 Minimum Capacity, k=i.
Capacity. -22.5. 13
Unit Cooler High Fan:
\2\ -19.5.
Capacity, Condition A, Maximum -22..................... 5 95 75 Maximum Capacity, k=2.
Capacity.
Off Cycle, Condition A............... ........................ .............. 95 75 Compressor Off.
[[Page 24008]]
Capacity, Condition B, Minimum -19..................... 28 59 54 Minimum Capacity, k=1.
Capacity.
Capacity, Condition B, Intermediate Unit Cooler Low Fan: \2\ 12 59 54 Minimum Capacity, k=i.
Capacity. -22.5. 13
Unit Cooler High Fan:
\2\ -19.5.
Capacity, Condition B, Maximum -22..................... 5 59 54 Maximum Capacity, k=2.
Capacity.
Off Cycle, Condition B............... ........................ .............. 59 54 Compressor Off.
Capacity, Condition C, Minimum -19..................... 23 35 34 Minimum Capacity, k=1.
Capacity.
Capacity, Condition C, Intermediate Unit Cooler Low Fan: \2\ 11 35 34 Minimum Capacity, k=i.
Capacity. -22.5. 12
Unit Cooler High Fan:
\2\ -19.5.
Capacity, Condition C, Maximum -22..................... 5 35 34 Maximum Capacity, k=2.
Capacity.
Off Cycle, Condition C............... ........................ .............. 35 34 Compressor Off.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
\1\ Required only for evaporative condensing units (e.g., incorporates a slinger ring).
\2\ When Digital Compressor duty cycle, variable-speed speed ratio, or staged compressor displacement ratio for intermediate capacity is 65% or less,
use the Unit Cooler Low Fan condition, otherwise use the Unit cooler High Fan condition.
Table 14--Test Operating Conditions for Variable- or Multiple-Capacity Low-Temperature Indoor Dedicated Condensing Units
--------------------------------------------------------------------------------------------------------------------------------------------------------
Condenser air
Suction dew point, Return gas, Condenser air entering wet-
Test title [deg]F [deg]F entering dry- bulb, [deg]F Compressor operating mode
bulb, [deg]F \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Capacity, Condition A, Minimum -19..................... 32 90 75 Minimum Capacity, k=1.
Capacity.
Capacity, Condition A, Intermediate Unit Cooler Low Fan: \2\ 13 90 75 Minimum Capacity, k=i.
Capacity. -22.5. 13
Unit Cooler High Fan:
\2\ -19.5.
Capacity, Condition A, Maximum -22..................... 5 90 75 Maximum Capacity, k=2.
Capacity.
Off Cycle, Condition A............... ........................ .............. 90 75 Compressor Off.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
\1\ Required only for evaporative condensing units (e.g., incorporates a slinger ring).
\2\ When Digital Compressor duty cycle, variable-speed speed ratio, or staged compressor displacement ratio for intermediate capacity is 65% or less,
use the Unit Cooler Low Fan condition, otherwise use the Unit cooler High Fan condition.
4.5.5 Test Operating Conditions for Two-Capacity Indoor Matched-
Pair or Single-Packaged Refrigeration Systems.
For two-capacity indoor medium-temperature matched-pair or
single-packaged refrigeration systems, conduct tests using the test
conditions specified in Table 15 of this appendix. For two-capacity
indoor low-temperature matched-pair or single-packaged refrigeration
systems, conduct tests using the test conditions specified in Table
16 of this appendix.
Table 15--Test Operating Conditions for Two-Capacity Medium-Temperature Indoor Matched-Pair or Single-Packaged Refrigeration Systems
--------------------------------------------------------------------------------------------------------------------------------------------------------
Unit cooler Unit cooler
air entering air entering Condenser air Condenser air entering wet-
Test description dry-bulb, relative entering dry- bulb, [deg]F Compressor status
[deg]F humidity, % bulb, [deg]F
--------------------------------------------------------------------------------------------------------------------------------------------------------
Capacity, Condition A, Low Capacity. 35 <50 90 75,\1\ 65 \2\............. Low Capacity.
Capacity, Condition A, High Capacity 35 <50 90 75,\1\ 65 \2\............. High Capacity.
Off Cycle,.......................... 35 <50 90 75,\1\ 65 \2\............. Off.
Condition A.........................
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
\1\ Required only for evaporative condensing units (e.g., incorporates a slinger ring).
\2\ Maximum allowable value for Single-Packaged Systems that do not use evaporative Dedicated Condensing Units, where all or part of the equipment is
located in the outdoor room.
[[Page 24009]]
Table 16--Test Operating Conditions for Two Capacity Low-Temperature Indoor Matched-Pair or Single-Packaged Refrigeration Systems
--------------------------------------------------------------------------------------------------------------------------------------------------------
Unit cooler Unit cooler
air entering air entering Condenser air Maximum condenser air
Test description dry-bulb, relative entering dry- entering wet-bulb, [deg]F Compressor status
[deg]F humidity, % bulb, [deg]F
--------------------------------------------------------------------------------------------------------------------------------------------------------
Capacity, Condition A, Low Capacity. -10 <50 90 75,\1\ 65 \2\............. Low Capacity.
Capacity, Condition A, High Capacity -10 <50 90 75,\1\ 65 \2\............. High Capacity.
Off Cycle, Condition A.............. -10 <50 90 75,\1\ 65 \2\............. Off.
Defrost............................. -10 <50 .............. .......................... System Dependent.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
\1\ Required only for evaporative condensing units (e.g., incorporates a slinger ring).
\2\ Maximum allowable value for Single-Packaged Systems that do not use evaporative Dedicated Condensing Units, where all or part of the equipment is
located in the outdoor room.
4.5.6 Test Conditions for Variable- or Multiple-Capacity Indoor
Matched Pair or Single-Packaged Refrigeration Systems.
For variable- or multiple-capacity indoor medium-temperature
matched-pair or single-packaged refrigeration systems, conduct tests
using the test conditions specified in Table 17 of this appendix.
For variable- or multiple-capacity indoor low-temperature matched-
pair or single-packaged refrigeration systems, conduct tests using
the test conditions specified in Table 18 of this appendix.
Table 17--Test Operating Conditions for Variable- or Multiple-Capacity Medium-Temperature Indoor Matched-Pair or Single-Packaged Refrigeration Systems
--------------------------------------------------------------------------------------------------------------------------------------------------------
Unit cooler Unit cooler
air entering air entering Condenser air Condenser air entering wet-
Test description dry-bulb, relative entering dry- bulb, [deg]F Compressor status
[deg]F humidity, % bulb, [deg]F
--------------------------------------------------------------------------------------------------------------------------------------------------------
Capacity, Condition A, Minimum 35 <50 90 75,\1\ 65 \2\............. Minimum Capacity.
Capacity.
Capacity, Condition A, Intermediate 35 <50 90 75,\1\ 65 \2\............. Intermediate Capacity.
Capacity.
Capacity, Condition A, High Capacity 35 <50 90 75,\1\ 65 \2\............. Maximum Capacity.
Off Cycle, Condition A.............. 35 <50 90 75,\1\ 65 \2\............. Off.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
\1\ Required only for evaporative condensing units (e.g., incorporates a slinger ring).
\2\ Maximum allowable value for Single-Packaged Systems that do not use evaporative Dedicated Condensing Units, where all or part of the equipment is
located in the outdoor room.
Table 18--Test Operating Conditions for Variable- or Multiple-Capacity Low-Temperature Indoor Matched-Pair or Single-Packaged Refrigeration Systems
--------------------------------------------------------------------------------------------------------------------------------------------------------
Unit cooler Unit cooler
air entering air entering Condenser air Maximum condenser air
Test description dry-bulb, relative entering dry- entering wet-bulb, [deg]F Compressor status
[deg]F humidity, % bulb, [deg]F
--------------------------------------------------------------------------------------------------------------------------------------------------------
Capacity, Condition A, Minimum -10 <50 90 75,\1\ 65 \2\............. Minimum Capacity.
Capacity.
Capacity, Condition A, Intermediate -10 <50 90 75,\1\ 65 \2\............. Intermediate Capacity.
Capacity.
Capacity, Condition A, Maximum -10 <50 90 75,\1\ 65 \2\............. Maximum Capacity.
Capacity.
Off Cycle, Condition A.............. -10 <50 90 75,\1\ 65 \2\............. Off.
Defrost............................. -10 <50 .............. .......................... System Dependent.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
\1\ Required only for evaporative condensing units (e.g., incorporates a slinger ring).
\2\ Maximum allowable value for Single-Packaged Systems that do not use evaporative Dedicated Condensing Units, where all or part of the equipment is
located in the outdoor room.
[[Page 24010]]
4.6. Calculation for Walk-in Box Load.
4.6.1 For medium- and low-temperature refrigeration systems with
indoor condensing units, calculate walk-in box loads for high and
low load periods as a function of net capacity as described in
Section 6.2.1 of AHRI 1250-2020.
4.6.2 For medium- and low-temperature refrigeration systems with
outdoor condensing units, calculate walk-in box loads for high and
low load periods as a function of net capacity and outdoor
temperature as described in Section 6.2.2 of AHRI 1250-2020.
4.6.3 For high-temperature refrigeration systems, calculate
walk-in box load as follows.
BBL = [middot] qss,A
Where qss,A is the measured net capacity for Test Condition A.
4.7. Calculation for Annual Walk-in Energy Factor (AWEF).
Calculations used to determine AWEF based on performance data
obtained for testing shall be as specified in Section 7 of AHRI
1250-2020 with modifications as indicated in sections 4.7.7 through
4.7.10 of this appendix. Calculations used to determine AWEF for
refrigeration systems not specifically identified in Sections 7.1.1
through 7.1.6 of AHRI 1250-2020 are enumerated in sections 4.7.1
through 4.7.6 and sections 4.7.11 through 4.7.14 of this appendix.
4.7.1 Two-Capacity Condensing Units Tested Alone, Indoor.
4.7.1.1 Unit Cooler Power.
Calculate maximum-capacity unit cooler power during the
compressor on period EBFcomp,on, in Watts, using Equation 130 of
AHRI 1250-2020 for medium-temperature refrigeration systems and
using Equation 173 of AHRI 1250-2020 for low-temperature
refrigeration systems.
Calculate unit cooler power during the compressor off period
EBFcomp,off, in Watts, as 20 percent of the maximum-capacity unit
cooler power during the compressor on period.
4.7.1.2 Defrost.
For freezer refrigeration systems, calculate defrost heat
contribution QBDF in Btu/h and the defrost average power consumption
DBF in W as a function of steady-state maximum gross refrigeration
capacity QBj, as specified in Section C10.2.2 of Appendix C of AHRI
1250-2020.
4.7.1.3 Net Capacity.
Calculate steady-state maximum net capacity, qZ, and minimum net
capacity, qF as follows:
qZ = QBj-3.412 [middot] EBFcomp,on
qF = QBj-3.412 [middot] 0.2 [middot] EBFcomp,on
Where:
QBj, and QBq, represent gross refrigeration capacity at maximum and
minimum capacity, respectively.
4.7.1.4 Calculate average power input during the low load period
as follows.
If the low load period box load, BLBL, plus defrost heat
contribution, QBDF (only applicable for freezers), is less than the
minimum net capacity qF:
[GRAPHIC] [TIFF OMITTED] TP21AP22.030
Where:
EBF is the steady state condensing unit power input for minimum-
capacity operation.
EBcu,off is the condensing unit off-cycle power input, measured as
described in Section C3.5 of AHRI 1250-2020.
If the low load period box load, BLBL, plus defrost heat
contribution, QBDF , (only applicable for freezers) is greater than
the minimum net capacity qF:
[GRAPHIC] [TIFF OMITTED] TP21AP22.031
4.1.7.5 Calculate average power input during the high load
period as follows.
[[Page 24011]]
[GRAPHIC] [TIFF OMITTED] TP21AP22.032
4.1.7.6 Calculate the AWEF as follows:
[GRAPHIC] [TIFF OMITTED] TP21AP22.033
4.7.2 Variable-Capacity or Multistage Condensing Units Tested
Alone, Indoor.
4.7.2.1 Unit Cooler Power.
Calculate maximum-capacity unit cooler power during the
compressor on period EBFcomp,on as described in section 4.7.1.1 of
this appendix.
Calculate unit cooler power during the compressor off period
EBFcomp,off, in Watts, as 20 percent of the maximum-capacity unit
cooler power during the compressor on period.
4.7.2.2 Defrost.
Calculate Defrost parameters as described in section 4.7.1.2 of
this appendix.
4.7.2.3 Net Capacity.
Calculate steady-state maximum net capacity, qBZ, intermediate
net capacity, qBF, and minimum net capacity, qBE, as follows:
qBZ = QBj - 3.412 [middot] EBFcomp,on
qBZ = QBj - 3.412 [middot] Kf EBFcomp,on
qBF = QBi - 3.412 [middot] 0.2 [middot] EBFcomp,on
Where:
QBj, QBm, QBq, and represent gross refrigeration capacity at
maximum, intermediate, and minimum capacity, respectively.
Kf is the unit cooler power coefficient for
intermediate capacity operation, set equal to 0.2 to represent low-
speed fan operation if the Duty Cycle for a Digital Compressor, the
Speed Ratio for a Variable-Speed Compressor, or the Displacement
Ratio for a Multi-Stage Compressor at Intermediate Capacity is 65%
or less, and otherwise set equal to 1.0.
4.7.2.4 Calculate average power input during the low load period
as follows.
If the low load period box load, BLBL, plus defrost heat
contribution QBDF (only applicable for freezers) is less than the
minimum net capacity:
[GRAPHIC] [TIFF OMITTED] TP21AP22.034
Where EBcu,off, in W, is the condensing unit off-mode power
consumption, measured as described in Section C3.5 of AHRI 1250-
2020.
If the low load period box load BLBL plus defrost heat
contribution QBDF (only applicable for freezers) is greater than the
minimum net capacity and less than the intermediate net capacity
qBE:
[GRAPHIC] [TIFF OMITTED] TP21AP22.035
Where:
EER\k=1\ is the minimum-capacity energy efficiency ratio, equal to
qBF divided by EBF + EBFcomp,on; and
EER\k=i\ is the intermediate-capacity energy efficiency ratio, equal
to qBE divided by EBE + EBFcomp,on.
4.7.2.5 Calculate average power input during the high load
period as follows:
If the high load period box load, BLBH, plus defrost heat
contribution, QBDF (only applicable for freezers), is greater than
the minimum net capacity qBF and less than the intermediate net
capacity qBE:
[[Page 24012]]
[GRAPHIC] [TIFF OMITTED] TP21AP22.036
If the high load period box load, BLBH, plus defrost heat
contribution, QBDF (only applicable for freezers), is greater than
the intermediate net capacity qBE and less than the maximum net
capacity, qBZ:
[GRAPHIC] [TIFF OMITTED] TP21AP22.037
Where:
EER\k=2\ is the maximum-capacity energy efficiency ratio, equal to
qBZ divided by EBZ + EBFcomp,on
4.7.2.6 Calculate the AWEF as follows.
[GRAPHIC] [TIFF OMITTED] TP21AP22.038
4.7.3 Two-Capacity Condensing Units Tested Alone, Outdoor.
4.7.3.1 Unit Cooler Power.
Calculate maximum-capacity unit cooler power during the
compressor on period EBFcomp,on, in Watts, using Equation 153 of
AHRI 1250-2020 for medium-temperature refrigeration systems and
using Equation 196 of AHRI 1250-2020 for low-temperature
refrigeration systems.
Calculate unit cooler power during the compressor off period
EBFcomp,off, in Watts, as 20 percent of the maximum-capacity unit
cooler power during the compressor on period.
4.7.3.2 Defrost.
Calculate Defrost parameters as described in section 4.7.1.2.
4.7.3.3 Condensing Unit Off-Cycle Power.
Calculate Condensing Unit Off-Cycle Power for temperature
tj as follows.
[GRAPHIC] [TIFF OMITTED] TP21AP22.039
Where EBcu,off,A and EBcu,off,C are the Condensing Unit off-
cycle power measurements for test conditions A and C, respectively,
measured as described in Section C3.5 of AHRI 1250-2020. If
tj is greater than 35 [deg]F and less than 59 [deg]F, use
Equation 157 of AHRI 1250-2020, and if tj is greater than
or equal to 59 [deg]F and less than 95 [deg]F, use Equation 159.
4.7.3.4 Net Capacity and Condensing Unit Power Input.
Calculate steady-state maximum net capacity, qBZ(tj),
and minimum net capacity, qBZ(tj), and corresponding
condensing unit power input levels EBZ(tj) and
EBF(tj) as a function of outdoor temperature
tj as follows:
[[Page 24013]]
[GRAPHIC] [TIFF OMITTED] TP21AP22.040
Where:
The capacity level k can equal 1 or 2;
QBs and QBw represent gross refrigeration capacity at maximum and
minimum capacity, respectively, for test condition X, which can take
on values A, B, or C;
EBb and EBg represent condensing unit power input at maximum and
minimum capacity, respectively for test condition X.
4.7.3.5 Calculate average power input during the low load period
as follows.
Calculate the temperature, tIL, below which the low
load period box load, BLBL(tj), plus defrost heat contribution, QBDF
(only applicable for freezers), is less than the minimum net
capacity, qF(tj), by solving the following equation for
tIL:
BLBL(tIL) + QBDF = qF(tIL)
For tj < tIL:
[GRAPHIC] [TIFF OMITTED] TP21AP22.041
Where EBcu,off(tj), in W, is the condensing unit off-mode power
consumption for temperature tj, determined as indicated
in section 4.7.3.3 of this appendix.
For tj >= tIL:
[GRAPHIC] [TIFF OMITTED] TP21AP22.042
4.7.3.6 Calculate average power input during the high load
period as follows.
Calculate the temperature, tIH, below which the high
load period box load, BLBH(tj), plus defrost heat contribution, QBDF
(only applicable for freezers), is less than the
[[Page 24014]]
minimum net capacity, qF(tj), by solving the following equation for
tIH:
BLBH(tIH) + QBDF = qF(tIH)
Calculate the temperature, tIIH, below which the high
load period box load BLBH(tj) plus defrost heat contribution QBDF
(only applicable for freezers) is less than the maximum net capacity
qZ(tj), by solving the following equation for tIIH:
BLBH(tIH) + QBDF = qF(tIIH)
For tj < tIH:
[GRAPHIC] [TIFF OMITTED] TP21AP22.043
For tIH <= tj < tIIH:
[GRAPHIC] [TIFF OMITTED] TP21AP22.044
For tIIH <= tj:
EBH(tj) + (EBZ(tj) + EBFcomp,on
4.7.3.7 Calculate the AWEF as follows:
[GRAPHIC] [TIFF OMITTED] TP21AP22.045
4.7.4 Variable-Capacity or Multistage Condensing Units Tested
Alone, Outdoor.
4.7.4.1 Unit Cooler Power.
Calculate maximum-capacity unit cooler power during the
compressor on period EBFcomp,on as described in section 4.7.1.1 of
this appendix.
Calculate unit cooler power during the compressor off period
EBFcomp,off, in Watts, as 20 percent of the maximum-capacity unit
cooler power during the compressor on period.
4.7.4.2 Defrost.
Calculate Defrost parameters as described in section 4.7.1.2.
4.7.4.3 Condensing Unit Off-Cycle Power.
Calculate Condensing Unit Off-Cycle Power for temperature,
tj, as described in section 4.7.3.3 of this appendix.
4.7.4.4 Net Capacity and Condensing Unit Power Input.
Calculate steady-state maximum net capacity, qZ(tj),
intermediate net capacity, qF(tj), and minimum net capacity, qF(tj),
and corresponding condensing unit power input levels EBZ(tj),
EBF(tj), and EBF(tj) as a function of outdoor temperature,
tj, as follows:
If 35 [deg]F > tj >= 59 [deg]F:
[GRAPHIC] [TIFF OMITTED] TP21AP22.046
If 59 [deg]F >= tj > 95 [deg]F:
[[Page 24015]]
[GRAPHIC] [TIFF OMITTED] TP21AP22.047
Where:
The capacity level k can equal 1, i, or 2;
QBs, QBt and QBt represent gross refrigeration capacity at maximum,
intermediate, and minimum capacity, respectively, for test condition
X, which can take on values A, B, or C;
EBb and EBa represent condensing unit power input at maximum and
minimum capacity, respectively for test condition X; and
Kf is the unit cooler power coefficient for intermediate
capacity operation, set equal to 0.2 to represent low-speed fan
operation if the Duty Cycle for a Digital Compressor, the Speed
Ratio for a Variable-Speed Compressor, or the Displacement Ratio for
a Multi-Stage Compressor at Intermediate Capacity is 65% or less,
and otherwise set equal to 1.0.
4.7.4.5 Calculate average power input during the low load period
as follows.
Calculate the temperature, tIL, below which the low
load period box load BLBL(tj) plus defrost heat contribution, QBDF
(only applicable for freezers), is less than the minimum net
capacity, qF(tj), by solving the following equation for
tIL:
BLBL(tIL) + qF(tIL)
Calculate the temperature, tVL, below which the low
load period box load, BLBL(tj), plus defrost heat contribution, QBDF
(only applicable for freezers), is less than the intermediate net
capacity, qF(tj), by solving the following equation for
tVL:
BLBL(tVL) + QBDF = qE(tVL)
For tj < tIL:
[GRAPHIC] [TIFF OMITTED] TP21AP22.048
Where EBcu,off(tj), in W, is the condensing unit off-mode power
consumption for temperature, tj, determined as indicated
in section 4.7.3.3 of this appendix.
For tIL <= tj < tVL:
[GRAPHIC] [TIFF OMITTED] TP21AP22.049
For tVL <= tj:
[GRAPHIC] [TIFF OMITTED] TP21AP22.050
[[Page 24016]]
Where:
EER\k=1\(tj) is the minimum-capacity energy efficiency
ratio, equal to qF(tj) divided by EBF(tj) + 0.2 [middot] EBFcomp,on;
EER\k=i\(tj) is the intermediate-capacity energy
efficiency ratio, equal to qE(tj) divided by EBssk=i(tj) + Kf
[middot] EBFcomp,on; and
EER\k=2\(tj) is the maximum-capacity energy efficiency
ratio, equal to qZ(tj) divided by EBZ(tj) + EBFcomp,on
4.7.4.6 Calculate average power input during the high load
period as follows.
Calculate the temperature tVH below which the high
load period box load BLBH(tj) plus defrost heat contribution QBDF
(only applicable for freezers) is less than the intermediate net
capacity qE(tj), by solving the following equation for
tVH:
BLBH(tVH) + QBDF = qssk=i(tVH)
Calculate the temperature tIIH below which the high
load period box load BLBH(tj) plus defrost heat contribution QBDF
(only applicable for freezers) is less than the maximum net capacity
qZ(tj), by solving the following equation for tIIH:
BLBH(tIIH) + QBDF = qZs(tIIH)
For tj < tVH:
[GRAPHIC] [TIFF OMITTED] TP21AP22.051
For tVH <= tj < tIIH:
[GRAPHIC] [TIFF OMITTED] TP21AP22.052
For tIIH <= tj:
EBH(tj) = (EBZ(tj) + EBFcomp,on)
4.7.4.7 Calculate the AWEF as follows:
[GRAPHIC] [TIFF OMITTED] TP21AP22.053
4.7.5 Two-Capacity Indoor Matched Pairs or Single-Packaged
Refrigeration Systems Other than High-Temperature.
4.7.5.1 Defrost.
For freezer refrigeration systems, defrost heat contribution
QBDF in Btu/h and the defrost average power consumption DBF in W
shall be as measured in accordance with Section C10.2.1 of Appendix
C of AHRI 1250-2020.
4.7.5.2 Calculate average power input during the low load period
as follows.
If the low load period box load BLBL plus defrost heat
contribution QBDF (only applicable for freezers) is less than the
minimum net capacity qF:
[GRAPHIC] [TIFF OMITTED] TP21AP22.054
Where:
qF and EBF> are the steady state refrigeration system minimum net
capacity, in Btu/h, and associated refrigeration system power input,
in W, respectively, for minimum-capacity operation, measured as
described in AHRI 1250-2020.
EBFcomp,off and EBcu,off, both in W, are the unit cooler and
condensing unit, respectively, off-mode power consumption, measured
as described in Section C3.5 of AHRI 1250-2020.
If the low load period box load BLBL plus defrost heat
contribution QBDF (only applicable for freezers) is greater than the
minimum net capacity qF:
[[Page 24017]]
[GRAPHIC] [TIFF OMITTED] TP21AP22.055
Where qZ and EBZ are the steady state refrigeration system
maximum net capacity, in Btu/h, and associated refrigeration system
power input, in W, respectively, for maximum-capacity operation,
measured as described in AHRI 1250-2020.
4.7.5.3 Calculate average power input during the high load
period as follows.
[GRAPHIC] [TIFF OMITTED] TP21AP22.056
4.7.5.4 Calculate the AWEF as follows:
[GRAPHIC] [TIFF OMITTED] TP21AP22.057
4.7.6 Variable-Capacity or Multistage Indoor Matched Pairs or
Single-Packaged Refrigeration Systems Other than High-Temperature.
4.7.6.1 Defrost.
For freezer refrigeration systems, defrost heat contribution in
Btu/h and the defrost average power consumption in W shall be as
measured in accordance with Section C10.2.1 of Appendix C of AHRI
1250-2020.
4.7.6.2 Calculate average power input during the low load period
as follows.
If the low load period box load BLBL plus defrost heat
contribution QBDF (only applicable for freezers) is less than the
minimum net capacity qF
[GRAPHIC] [TIFF OMITTED] TP21AP22.058
Where:
qF and EBF are the steady state refrigeration system minimum net
capacity, in Btu/h, and associated refrigeration system power input,
in W, respectively, for minimum-capacity operation, measured as
described in AHRI 1250-2020; and
EBFcomp,off and EBcu,off, both in W, are the unit cooler and
condensing unit, respectively, off-mode power consumption, measured
as described in Section C3.5 of AHRI 1250-2020.
If the low load period box load BLBL plus defrost heat
contribution QBDF (only applicable for freezers) is greater than the
minimum net capacity qF and less than the intermediate net capacity
qE:
[GRAPHIC] [TIFF OMITTED] TP21AP22.059
[GRAPHIC] [TIFF OMITTED] TP21AP22.060
[[Page 24018]]
Where:
EER\k=1\ is the minimum-capacity energy efficiency ratio, equal to
qF divided by EBF;
qF and EBF are the steady state refrigeration system intermediate
net capacity, in Btu/h, and associated refrigeration system power
input, in W, respectively, for intermediate-capacity operation,
measured as described in AHRI 1250-2020.
EER\k=i\ is the intermediate-capacity energy efficiency ratio, equal
to qE divided by EBF.
4.7.6.3 Calculate average power input during the high load
period as follows.
If the high load period box load BLBH plus defrost heat
contribution QBDF (only applicable for freezers) is greater than the
minimum net capacity qF and less than the intermediate net capacity
qE:
[GRAPHIC] [TIFF OMITTED] TP21AP22.061
If the high load period box load BLBH plus defrost heat
contribution QBDF (only applicable for freezers) is greater than the
intermediate net capacity qE and less than the maximum net capacity
qZ:
[GRAPHIC] [TIFF OMITTED] TP21AP22.062
Where:
qZ and EBZ are the steady state refrigeration system maximum net
capacity, in Btu/h, and associated refrigeration system power input,
in W, respectively, for maximum-capacity operation, measured as
described in AHRI 1250-2020; and
EER\k=2\ is the maximum-capacity energy efficiency ratio, equal toqZ
divided by EBZ.
4.7.6.4 Calculate the AWEF as follows.
[GRAPHIC] [TIFF OMITTED] TP21AP22.063
4.7.7 Variable-Capacity or Multistage Outdoor Matched Pairs or
Single-Packaged Refrigeration Systems Other than High-Temperature.
Calculate AWEF as described in Section 7.6 of AHRI 1250-2020,
with the following revisions.
4.7.7.1 Condensing Unit Off-Cycle Power.
Calculate condensing unit off-cycle power for temperature
tj as indicated in section 4.7.3.3 of this appendix.
Replace the constant value EBCU,off in Equations 55 and 70 of AHRI
1250-2020 with the values EBCU,off(tj), which vary with outdoor
temperature tj.
4.7.7.2 Unit Cooler Off-Cycle Power.
Set unit cooler Off-Cycle power EBFcomp,off equal to the average
of the unit cooler off-cycle power measurements made for test
conditions A, B, and C.
4.7.7.3 Average Power During the Low Load Period.
Calculate average power for intermediate-capacity compressor
operation during the low load period EBss,Lk=v(tj) as described in
Section 7.6 of AHRI 1250-2020, except that, instead of calculating
intermediate-capacity compressor EER using Equation 77, calculate
EER as follows.
For tj < tVL:
[GRAPHIC] [TIFF OMITTED] TP21AP22.064
For tVL <= tj:
[GRAPHIC] [TIFF OMITTED] TP21AP22.065
[[Page 24019]]
Where:
EER\k=1\(tj) is the minimum-capacity energy efficiency
ratio, equal to qF(tj) divided by EBFk=1(tj);
EER\k=i\(tj) is the intermediate-capacity energy
efficiency ratio, equal to qF(tj) divided by EBF(tj); and
EER\k=2\(tj) is the maximum-capacity energy efficiency
ratio, equal to qF(tj) divided by EBZ(tj)
4.7.7.4 Average Power During the High Load Period.
Calculate average power for intermediate-capacity compressor
operation during the high load period EBS(tj) as described in
Section 7.6 of AHRI 1250-2020, except that, instead of calculating
intermediate-capacity compressor EER using Equation 61, calculate
EER as follows:
For tj < tVH:
[GRAPHIC] [TIFF OMITTED] TP21AP22.066
For tVH <= tj:
[GRAPHIC] [TIFF OMITTED] TP21AP22.067
4.7.8 Two-Capacity Outdoor Matched Pairs or Single-Packaged
Refrigeration Systems Other than High-Temperature.
Calculate AWEF as described in Section 7.5 of AHRI 1250-2020,
with the following revisions for Condensing Unit Off-Cycle Power and
Unit Cooler Off-Cycle Power. Calculate condensing unit off-cycle
power for temperature tj as indicated in section 4.7.3.3
of this appendix. Replace the constant value EBCU,off in Equations
13 and 29 of AHRI 1250-2020 with the values EBCU,off(tj), which vary
with outdoor temperature (tj. Set unit cooler Off-Cycle
power EBFcomp,off equal to the average of the unit cooler off-cycle
power measurements made for test conditions A, B, and C.
4.7.9 Single-capacity Outdoor Matched Pairs or Single-Packaged
Refrigeration Systems Other than High-Temperature.
Calculate AWEF as described in Section 7.4 of AHRI 1250-2020,
with the following revision for Condensing Unit Off-Cycle Power and
Unit Cooler Off-cycle Power. Calculate condensing unit off-cycle
power for temperature tj as indicated in section 4.7.3.3
of this appendix. Replace the constant value EBCU,off in Equations
13 of AHRI 1250-2020 with the values EBCU,off(tj), which vary with
outdoor temperature tj. Set unit cooler Off-Cycle power
EBFcomp,off equal to the average of the unit cooler off-cycle power
measurements made for test conditions A, B, and C.
4.7.10 Single-capacity Condensing Units, Outdoor.
Calculate AWEF as described in Section 7.9 of AHRI 1250-2020,
with the following revision for Condensing Unit Off-Cycle Power.
Calculate condensing unit off-cycle power for temperature
tj as indicated in section 4.7.3.3 of this appendix
rather than as indicated in equations 157, 159, 202, and 204 of AHRI
1250-2020.
4.7.11 High-Temperature Matched Pairs or Single-Packaged
Refrigeration Systems, Indoor.
4.7.11.1 Calculate Load Factor LF as follows:
[GRAPHIC] [TIFF OMITTED] TP21AP22.068
Where:
BBL, in Btu/h is the non-equipment-related box load calculated as
described in section 4.6.3 of this appendix;
EBFcomp,off, in W, is the unit cooler off-cycle power consumption,
equal to 0.1 times the unit cooler on-cycle power consumption; and
qBss,A, in Btu/h is the measured net capacity for test condition A.
4.7.11.2 Calculate the AWEF as follows:
[GRAPHIC] [TIFF OMITTED] TP21AP22.069
Where:
EBss,A, in W, is the measured system power input for test condition
A; and
EBcu,off, in W, is the condensing unit off-cycle power consumption,
measured as described in Section C3.5 of AHRI 1250-2020.
4.7.12 High-Temperature Matched Pairs or Single-Packaged
Refrigeration Systems, Outdoor.
4.7.12.1 Calculate Load Factor LF(tj) for outdoor
temperature tj as follows:
[GRAPHIC] [TIFF OMITTED] TP21AP22.070
Where:
BBL, in Btu/h, is the non-equipment-related box load calculated as
described in section 4.6.3 of this appendix;
EBFcomp,off, in W, is the unit cooler off-cycle power consumption,
equal to 0.1 times the unit cooler on-cycle power consumption; and
qBss(tj), in Btu/h, is the net capacity for outdoor temperature
tj, calculated as described in Section 7.4.2 of AHRI
1250-2020.
4.7.12.2 Calculate the AWEF as follows:
[[Page 24020]]
[GRAPHIC] [TIFF OMITTED] TP21AP22.071
Where:
EBss(tj), in W, is the system power input for temperature
tj, calculated as described in Section 7.4.2 of AHRI
1250-2020;
EBcu,off in W, is the condensing unit off-cycle power consumption,
measured as described in Section C3.5 of AHRI 1250-2020; and
nj are the hours for temperature bin j.
4.7.13 High-Temperature Unit Coolers Tested Alone.
4.7.13.1 Calculate Refrigeration System Power Input as follows:
[GRAPHIC] [TIFF OMITTED] TP21AP22.072
Where:
qBmix,evap, in W, is the net evaporator capacity, measured as
described in AHRI 1250-2020;
EBFcomp,on, in W, is the unit cooler on-cycle power consumption; and
EER, in W, equals
[GRAPHIC] [TIFF OMITTED] TP21AP22.073
4.7.13.2 Calculate the load factor LF as follows:
[GRAPHIC] [TIFF OMITTED] TP21AP22.074
Where:
BBL, in Btu/h, is the non-equipment-related box load calculated as
described in section 4.6.3 of this appendix; and
EBFcomp,off, in W, is the unit cooler off-cycle power consumption,
equal to 0.1 times the unit cooler on-cycle power consumption.
4.7.13.3 Calculate AWEF as follows:
[GRAPHIC] [TIFF OMITTED] TP21AP22.075
4.7.14 CO2 Unit Coolers Tested Alone.
Calculate AWEF for CO2 Unit Coolers Tested Alone
using the calculations specified in in Section 7.8 of AHRI 1250-2020
for calculation of AWEF for Unit Cooler Tested Alone.
4.8. Test Method.
Test the Refrigeration System in accordance with AHRI 1250-2020
to determine refrigeration capacity and power input for the
specified test conditions, with revisions and additions as described
in this section.
4.8.1 Chamber Conditioning Using the Unit Under Test.
In Appendix C, Section C5.2.2 of AHRI 1250-2020, for applicable
system configurations (matched pairs, single-packaged refrigeration
systems, and standalone unit coolers), the unit under test may be
used to aid in achieving the required test chamber conditions prior
to beginning any steady state test. However, the unit under test
must be inspected and confirmed to be free from frost before
initiating steady state testing.
4.8.2 General Modification: Methods of Testing.
4.8.2.1 Refrigerant Temperature Measurements.
When testing a condensing unit alone, measure refrigerant liquid
temperature leaving the condensing unit as required in Section
C7.5.1.1.2 of Appendix C of AHRI 1250-2020 using the same
measurement approach specified for the unit cooler in Section C3.1.3
of Appendix C of AHRI 1250-2020. In all cases in which thermometer
wells or immersed sheathed sensors are prescribed, if the
refrigerant tube outer diameter is less than \1/2\ inch, the
refrigerant temperature may be measured using the average of two
temperature measuring instruments with a minimum accuracy of 0.5 [deg]F placed on opposite sides of the refrigerant tube
surface--resulting in a total of up to 8 temperature measurement
devices used for the DX Dual Instrumentation method. In this case,
the refrigerant tube shall be insulated with 1-inch thick insulation
from a point 6 inches upstream of the measurement location to a
point 6 inches downstream of the measurement location. Also, to
comply with this requirement, the unit cooler/evaporator entering
measurement location may be moved to a location 6 inches upstream of
the expansion device and, when testing a condensing unit alone, the
entering and leaving measurement locations may be moved to locations
6 inches from the respective service valves.
4.8.2.2 Mass Flow Meter Location.
[[Page 24021]]
When using the DX Dual Instrumentation test method of AHRI 1250-
2020, applicable for unit coolers, dedicated condensing units, and
matched pairs, the second mass flow meter may be installed in the
suction line as shown in Figure C1 of AHRI 1250-2020.
4.8.2.3 Subcooling at Refrigerant Mass Flow Meter.
In Section C3.4.5 of Appendix C of AHRI 1250-2020, when
verifying sub-cooling at the mass flow meters, only the sight glass
and a temperature sensor located on the tube surface under the
insulation are required. Subcooling shall be verified to be within
the 3 [deg]F requirement downstream of flow meters located in the
same chamber as a condensing unit under test and upstream of flow
meters located in the same chamber as a unit cooler under test,
rather than always downstream as indicated in AHRI 1250-2009,
Section C3.4.5. If the subcooling is less than 3 [deg]F when testing
a unit cooler, dedicated condensing unit, or matched pair (not a
single-packaged system), cool the line between the condensing unit
outlet and this location to achieve the required subcooling. When
providing such cooling while testing a matched pair, also measure
the refrigerant temperature upstream of the location that the line
is being cooled, and increase the temperature used to calculate unit
cooler entering enthalpy by the difference between the upstream and
downstream temperatures.
4.8.2.4 Installation Instructions.
Manufacturer installation instructions or installation
instructions described in this section refer to the instructions
that come packaged with or appear on the labels applied to the unit.
This does not include online manuals.
Installation Instruction Hierarchy: If a given installation
instruction provided on the label(s) applied to the unit conflicts
with the installation instructions that are shipped with the unit,
the label takes precedence. For testing of matched pairs, the
installation instructions for the dedicated condensing unit shall
take precedence. Setup shall be in accordance with the field
installation instructions (laboratory installation instructions
shall not be used). Achieving test conditions shall always take
precedence over installation instructions.
4.8.2.5 Refrigerant Charging and Adjustment of Superheat and
Subcooling.
All test samples shall be charged, and superheat and/or
subcooling shall be set, at Refrigeration A test conditions unless
otherwise specified in the installation instructions. If the
installation instructions give a specified range for superheat, sub-
cooling, or refrigerant pressure, the average of the range shall be
used as the refrigerant charging parameter target and the test
condition tolerance shall be 50 percent of the range.
Perform charging of near-azeotropic and zeotropic refrigerants only
with refrigerant in the liquid state. Once the correct refrigerant
charge is determined, all tests shall run until completion without
further modification.
4.8.2.5.1. When charging or adjusting superheat/subcooling, use
all pertinent instructions contained in the installation
instructions to achieve charging parameters within the tolerances.
However, in the event of conflicting charging information between
installation instructions, follow the installation instruction
hierarchy listed in section 4.8.2.4. Conflicting information is
defined as multiple conditions given for charge adjustment where all
conditions specified cannot be met. In the event of conflicting
information within the same set of charging instructions (e.g., the
installation instructions shipped with the dedicated condensing
unit), follow the hierarchy in Table 19 of this appendix for
priority. Unless the installation instructions specify a different
charging tolerance, the tolerances identified in Table 19 shall be
used.
Table 19--Test Condition Tolerances and Hierarchy for Refrigerant Charging and Setting of Refrigerant Conditions
----------------------------------------------------------------------------------------------------------------
Fixed orifice Expansion valve
--------------------------------------------------------------------------------------------
Priority Parameter with Parameter with
installation Tolerance installation Tolerance
instruction target instruction target
----------------------------------------------------------------------------------------------------------------
1.................. Super-heat............ 2.0 Sub-cooling.......... 10% of the Target
[deg]F. Value; No less than
0.5
[deg]F, No more than
2.0
[deg]F.
2.................. High Side Pressure or 4.0 psi High Side Pressure or 4.0 psi
Saturation or 1.0 Saturation or
Temperature. [deg]F. Temperature. 1.0
[deg]F.
3.................. Low Side Pressure or 2.0 psi Super-heat........... 2.0
Saturation or 0.8 [deg]F.
Temperature. [deg]F.
4.................. Low Side Temperature.. 2.0 Low Side Pressure or 2.0 psi
[deg]F. Saturation or
Temperature. 0.8
[deg]F.
5.................. High Side Temperature. 2.0 Approach Temperature. 1.0
[deg]F. [deg]F.
6.................. Charge Weight......... 2.0 oz... Charge Weight........ 0.5% or 1.0 oz,
whichever is
greater.
----------------------------------------------------------------------------------------------------------------
4.8.2.5.2. Dedicated Condensing Unit.
If the Dedicated Condensing Unit includes a receiver and the
subcooling target leaving the condensing unit provided in
installation instructions cannot be met without fully filling the
receiver, the subcooling target shall be ignored. Likewise, if the
Dedicated Condensing unit does not include a receiver and the
subcooling target leaving the condensing unit cannot be met without
the unit cycling off on high pressure, the subcooling target can be
ignored. Also, if no instructions for charging or for setting
subcooling leaving the condensing unit are provided in the
installation instructions, the refrigeration system shall be set up
with a charge quantity and/or exit subcooling such that the unit
operates during testing without shutdown (e.g., on a high-pressure
switch) and operation of the unit is otherwise consistent with the
requirements of the test procedure of this appendix and the
installation instructions.
4.8.2.5.3. Unit Cooler. Use the shipped expansion device for
testing. Otherwise, use the expansion device specified in the
installation instructions. If the installation instructions specify
multiple options for the expansion device, any specified expansion
device may be used. The supplied expansion device shall be adjusted
until either the superheat target is met, or the device reaches the
end of its adjustable range. In the event the device reaches the end
of its adjustable range and the super heat target is not met, test
with the adjustment at the end of its range providing the closest
match to the superheat target, and the test condition tolerance for
super heat target shall be ignored. The measured superheat is not
subject to a test operating tolerance. However, if the evaporator
exit condition is used to determine capacity using the DX dual-
instrumentation method or the refrigerant enthalpy method,
individual superheat value measurements may not be equal to or less
than zero. If this occurs, or if the operating tolerances of
measurements affected by expansion device fluctuation are exceeded,
the expansion device shall be replaced, operated at an average
superheat value higher than the target, or both, in order to avoid
individual superheat value measurements less than zero and/or to
meet the required operating tolerances.
4.8.2.5.4. Single-Packaged Unit. Unless otherwise directed by
the installation instructions, install one or more refrigerant line
pressure gauges during the setup of the unit, located depending on
the parameters used to verify or set charge, as described in this
section:
4.8.2.5.4.1. Install a pressure gauge in the liquid line if
charging is on the basis of subcooling, or high side pressure or
[[Page 24022]]
corresponding saturation or dew point temperature.
4.8.2.5.4.2. Install a pressure gauge in the suction line if
charging is on the basis of superheat, or low side pressure or
corresponding saturation or dew point temperature. Install this
gauge as close to the evaporator as allowable by the installation
instructions and the physical constraints of the unit. Use methods
for installing pressure gauge(s) at the required location(s) as
indicated in the installation instructions if specified.
4.8.2.5.4.3. If the installation instructions indicate that
refrigerant line pressure gauges should not be installed and the
unit fails to operate due to high pressure or low pressure
compressor cut off, then a charging port shall be installed, and the
unit shall be evacuated of refrigerant and charged to the nameplate
charge.
4.8.2.6 Ducted Units.
For systems with ducted evaporator air, or that can be installed
with or without ducted evaporator air: Connect ductwork on both the
inlet and outlet connections and determine external static pressure
(ESP) as described in Sections 6.4 and 6.5 of ANSI/ASHRAE 37. Use
pressure measurement instrumentation as described in Section 5.3.2
of ANSI/ASHRAE 37. Test at the fan speed specified in the
installation instructions--if there is more than one fan speed
setting and the installation instructions do not specify which speed
to use, test at the highest speed. Conduct tests with the ESP equal
to 50% of the maximum ESP allowed in the installation instructions,
within a tolerance of -0.00/+0.05 inches of water column. If the
installation instructions do not provide the maximum ESP, the ESP
shall be set for testing such that the air volume rate is \2/3\ of
the air volume rate measured when the ESP is 0.00 inches of water
column within a tolerance of -0.00/+0.05 inches of water column.
If testing using either the indoor or outdoor air enthalpy
method to measure the air volume rate, adjust the airflow
measurement apparatus fan to set the external static pressure--
otherwise, set the external static pressure by symmetrically
restricting the outlet of the test duct. In case of conflict, these
requirements for setting airflow take precedence over airflow values
specified in manufacturer installation instructions or product
literature.
4.8.2.7 Two-Speed or Multiple-Speed Evaporator Fans. Two-Speed
or Multiple-Speed evaporator fans shall be considered to meet the
qualifying control requirements of Section C4.2 of Appendix C of
AHRI 1250-2020 for measuring off-cycle fan energy if they use a fan
speed no less than 50% of the speed used in the maximum capacity
tests.
4.8.2.8 Defrost.
Use Section C10.2.1 of Appendix C of AHRI 1250-2020 for defrost
testing. The Test Room Conditioning Equipment requirement of Section
C10.2.1.1 of Appendix C of AHRI 1250-2020 does not apply.
4.8.2.8.1 Adaptive Defrost.
When testing to certify compliance to the energy conservation
standards, use NDF = 4, as instructed in Section
C10.2.1.7 or C10.2.2.1 of AHRI 1250-2020. When determining the
represented value of the calculated benefit for the inclusion of
adaptive defrost, use NDF = 2.5, as instructed in Section
C10.2.1.7 or C10.2.2.1 of AHRI 1250-2020.
4.8.2.8.2 Hot Gas Defrost.
When testing to certify compliance to the energy conservation
standards, remove the hot gas defrost mechanical components and
disconnect all such components from electrical power. Test the units
as if they are electric defrost units, but do not conduct the
defrost tests described in Section C10.2.1 of AHRI 1250-2020. Use
the defrost heat and power consumption values as described in
Section C10.2.2 of AHRI 1250-2020 for the AWEF calculations.
When determining the represented value of the calculated benefit
for the inclusion of hot gas defrost, test with hot gas mechanical
components installed, but do not conduct the defrost tests. Use the
defrost heat and power consumption values as described in Section
C10.1.1 of AHRI 1250-2020 for the AWEF calculations.
4.8.2.9 Dedicated condensing units that are not matched for
testing and are not single-packaged dedicated systems.
The temperature measurement requirements of sections C3.1.3 and
C4.1.3.1 Appendix C of AHRI 1250-2020 shall apply only to the
condensing unit exit rather than to the unit cooler inlet and
outlet, and they shall be applied for two measurements when using
the DX Dual Instrumentation test method.
4.8.2.10 Single-packaged dedicated systems.
Use the test method in section C9 of Appendix C of AHRI 1250-
2020 as the method of test for single-packaged dedicated systems,
with modifications as described in this section. Use two test
methods listed in Table 20 of this appendix to calculate the net
capacity and power consumption. The test method listed with a lower
``Hierarchy Number'' and that has ``Primary'' as an allowable use in
Table 20 shall be considered the primary measurement and used as the
net capacity.
Table 20--Single-Packaged Methods of Test and Hierarchy
----------------------------------------------------------------------------------------------------------------
Hierarchy No. Method of test Allowable use
----------------------------------------------------------------------------------------------------------------
1..................................... Balanced Ambient Indoor Primary.
Calorimeter.
2..................................... Indoor Air Enthalpy........... Primary or Secondary.
3..................................... Indoor Room Calorimeter....... Primary or Secondary.
4..................................... Balanced Ambient Outdoor Secondary.
Calorimeter.
5..................................... Outdoor Air Enthalpy.......... Secondary.
6..................................... Outdoor Room Calorimeter...... Secondary.
7..................................... Single-Packaged Refrigerant Secondary.
Enthalpy\1\.
8..................................... Compressor Calibration........ Secondary.
----------------------------------------------------------------------------------------------------------------
Notes:
\1\ See description of the single-packaged refrigerant enthalpy method in section 4.8.2.10.1 of this appendix.
4.8.2.10.1 Single-Packaged Refrigerant Enthalpy Method.
The single-packaged refrigerant enthalpy method shall follow the
test procedure of the DX Calibrated Box method in AHRI 1250-2020,
Appendix C, section C8 for refrigerant-side measurements with the
following modifications.
4.8.2.10.1.1 Air-side measurements shall follow the requirements
of the primary single-packaged method listed in Table 20 of this
appendix. The air-side measurements and refrigerant-side
measurements shall be collected over the same intervals.
4.8.2.10.1.2 A preliminary test at Test Rating Condition A is
required using the primary method prior to any modification
necessary to install the refrigerant-side measuring instruments.
Install surface mount temperature sensors on the evaporator and
condenser coils at locations not affected by liquid subcooling or
vapor superheat (i.e., near the midpoint of the coil at a return
bend), entering and leaving the compressor, and entering the
expansion device. These temperature sensors shall be included in the
regularly recorded data.
4.8.2.10.1.3 After the preliminary test is completed, the
refrigerant shall be removed from the equipment and the refrigerant-
side measuring instruments shall be installed. The equipment shall
then be evacuated and recharged with refrigerant. Once the equipment
is operating at Test Condition A, the refrigerant charge shall be
adjusted until, as compared to the average values from the
preliminary test, the following conditions are achieved:
(1) Each on-coil temperature sensor indicates a reading that is
within 1.0 [deg]F of the measurement in the initial
test,
(2) The temperatures of the refrigerant entering and leaving the
compressor are within 4 [deg]F, and
(3) The refrigerant temperature entering the expansion device is
within 1 [deg]F. Once these conditions have been
achieved over an interval of at least ten minutes, refrigerant
[[Page 24023]]
charging equipment shall be removed and the official tests shall be
conducted.
4.8.2.10.1.4 The lengths of liquid line to be added shall be 5
feet maximum, not including the requisite flow meter. This maximum
length applies to each circuit separately.
4.8.2.10.1.5 Use section C9.2 of Appendix C of AHRI 1250-2020
for allowable refrigeration capacity heat balance. Calculate the
single-packaged refrigerant enthalpy (secondary) method test net
capacity QBnet,secondary as follows:
QBnet,secondary = QBref-3.412.EBFcomp,on-QBsploss
Where:
QBref is the gross capacity;
EBFcomp,on is the evaporator compartment on-cycle power, including
evaporator fan power; and
QBsploss is a duct loss calculation applied to the evaporator
compartment of the single-packaged systems, which is calculated as
indicated below.
QBsploss = UAcond x (Tevapside-Tcondside) + UAamb x (Tevapside-Tamb)
Where:
UAcond and UAamb are, for the condenser/
evaporator partition and the evaporator compartment walls exposed to
ambient air, respectively, the product of the overall heat transfer
coefficient and surface area of the unit as manufactured, i.e.,
without external insulation that might have been added during the
test. The areas shall be calculated based on measurements, and the
thermal resistance values shall be based on insulation thickness and
insulation material;
Tevapside is the air temperature in the evaporator
compartment--the measured evaporator air inlet temperature may be
used;
Tcondside is the air temperature in the condenser
compartment--the measured chamber ambient temperature may be used,
or a measurement may be made using a temperature sensor placed
inside the condenser box at least 6 inches distant from any part of
the refrigeration system; and
Tamb is the air temperature outside the single-packaged
system.
4.8.2.10.1.6 For multi-circuit single-packaged systems utilizing
the single-packaged refrigerant enthalpy method, apply the test
method separately for each circuit and sum the separately-calculated
refrigerant-side gross refrigeration capacities.
4.8.2.10.2 Detachable single-packaged systems shall be tested as
single-packaged dedicated refrigeration systems.
4.8.2.11 Variable-Capacity and Multiple-Capacity Dedicated
Condensing Refrigeration Systems.
4.8.2.11.1 Manufacturer-Provided Equipment Overrides.
Where needed, the manufacturer must provide a means for
overriding the controls of the test unit so that the compressor(s)
operates at the specified speed or capacity and the indoor blower
operates at the speed consistent with the compressor operating level
as would occur without override.
4.8.2.11.2 Compressor Operating Levels.
For variable-capacity and multiple-capacity compressor systems,
the minimum capacity for testing shall be the minimum capacity that
the system control would operate the compressor in normal operation.
Likewise, the maximum capacity for testing shall be the maximum
capacity that the system control would operate the compressor in
normal operation. For variable-speed compressor systems, the
intermediate speed for testing shall be the average of the minimum
and maximum speeds. For digital compressor systems, the intermediate
duty cycle shall be the average of the minimum and maximum duty
cycles. For multiple-capacity compressor systems with three capacity
levels, the intermediate operating level for testing shall be the
middle capacity level. For multiple-capacity compressor systems with
more than three capacity levels, the intermediate operating level
for testing shall be the level whose displacement ratio is closest
to the average of the maximum and minimum displacement ratios.
4.8.2.11.3 Refrigeration Systems with Digital Compressor(s).
Use the test methods described in section 4.8.2.10.1 of this
appendix as the secondary method of test for refrigeration systems
with digital compressor(s) with modifications as described in this
section. The Test Operating tolerance for refrigerant mass flow rate
and suction pressure in Table 2 of AHRI 1250-2020 shall be ignored.
Temperature and pressure measurements used to calculate QBref shall
be recorded at a frequency of once per second or faster and based on
average values measured over the 30-minute test period.
4.8.2.11.3.1 For Matched pair (not including single-packaged
systems) and Dedicated Condensing Unit refrigeration systems, the
preliminary test in sections 4.8.2.10.1.2 and 4.8.2.10.1.3 of this
appendix is not required. The liquid line and suction line shall be
25 feet 3 inches, not including the requisite flow
meters. Also, the term QBsploss in the equation to calculate net
capacity shall be set equal to zero.
4.8.2.11.3.2 For Dedicated Condensing Unit refrigeration
systems, the primary capacity measurement method shall be balanced
ambient outdoor calorimeter, outdoor air enthalpy, or outdoor room
calorimeter.
[FR Doc. 2022-06423 Filed 4-20-22; 8:45 am]
BILLING CODE 6450-01-P