[Federal Register Volume 87, Number 167 (Tuesday, August 30, 2022)]
[Proposed Rules]
[Pages 53302-53359]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-17075]



[[Page 53301]]

Vol. 87

Tuesday,

No. 167

August 30, 2022

Part IV





 Department of Energy





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10 CFR Parts 429 and 431





Energy Conservation Program: Test Procedure for Water-Source Heat 
Pumps; Proposed Rule

  Federal Register / Vol. 87, No. 167 / Tuesday, August 30, 2022 / 
Proposed Rules  

[[Page 53302]]


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DEPARTMENT OF ENERGY

10 CFR Parts 429 and 431

[EERE-2017-BT-TP-0029]
RIN 1904-AE05


Energy Conservation Program: Test Procedure for Water-Source Heat 
Pumps

AGENCY: Office of Energy Efficiency and Renewable Energy, Department of 
Energy.

ACTION: Notice of proposed rulemaking and request for comment.

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SUMMARY: The U.S. Department of Energy (``DOE'') proposes to amend its 
test procedures for water-source heat pumps, with the main changes 
being ones to expand the scope of applicability of the test procedure, 
reference different industry standards than currently referenced, 
change to a seasonal cooling efficiency metric, and change the test 
conditions used for the heating metric. DOE has tentatively determined 
that the amended test procedure would produce results that are more 
representative of an average use cycle and more consistent with current 
industry practice without being unduly burdensome to conduct. DOE seeks 
comment from interested parties on this proposal.

DATES: 
    Comments: DOE will accept comments, data, and information regarding 
this proposal no later than October 31, 2022. See section V, ``Public 
Participation,'' for details.
    Public Meeting: DOE will hold a public meeting via webinar on 
Wednesday, September 14, 2022, from 1:00 p.m. to 3:00 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-0029. Follow the instructions for submitting 
comments. Alternatively, interested persons may submit comments, 
identified by docket number EERE-2017-BT-TP-0029 and/or RIN 1904-AE05, 
by any of the following methods:
    Email: [email protected]. Include the docket number EERE-
2017-BT-TP-0029 and/or RIN 1904-AE05 in the subject line of the 
message.
    Postal Mail: Appliance and Equipment Standards Program, U.S. 
Department of Energy, Building Technologies Office, Mailstop EE-5B, 
1000 Independence Avenue SW, Washington, DC 20585-0121. If possible, 
please submit all items on a compact disc (``CD''), in which case it is 
not necessary to include printed copies.
    Hand Delivery/Courier: Appliance and Equipment Standards Program, 
U.S. Department of Energy, Building Technologies Office, 950 L'Enfant 
Plaza SW, 6th Floor, Washington, DC 20024. Telephone: (202) 287-1445. 
If possible, please submit all items on a CD, in which case it is not 
necessary to include printed copies.
    No telefacsimiles (``faxes'') will be accepted. For detailed 
instructions on submitting comments and additional information on this 
process, see section V of this document (Public Participation).
    Docket: The docket, which includes Federal Register notices, public 
meeting/webinar attendee lists and transcripts, 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?D=EERE-2017-BT-TP-0029. The docket web page contains 
instructions on how to access all documents, including public comments, 
in the docket. See section V (Public Participation) for information on 
how to submit comments through www.regulations.gov.

FOR FURTHER INFORMATION CONTACT: 
    Ms. Catherine Rivest, U.S. Department of Energy, Office of Energy 
Efficiency and Renewable Energy, Building Technologies Office, EE-5B, 
1000 Independence Avenue SW, Washington, DC 20585-0121. Telephone: 
(202) 586-7335. Email: [email protected].
    Mr. Eric Stas, U.S. Department of Energy, Office of the General 
Counsel, GC-33, 1000 Independence Avenue SW, Washington, DC 20585-0121. 
Telephone: (202) 586-5827. Email: [email protected].
    For further information on how to submit a comment, review other 
public comments and the docket, or participate in the public meeting 
webinar, contact the Appliance and Equipment Standards Program staff at 
(202) 287-1445 or by email: [email protected].

SUPPLEMENTARY INFORMATION: DOE proposes to incorporate by reference 
already-approved industry standards, an update to one of those 
standards, and a standard not previously-approved.
    ANSI/ASHRAE Standard 37-2009, ``Methods of Testing for Rating 
Electrically Driven Unitary Air-Conditioning and Heat Pump Equipment,'' 
including errata sheet issued March 27, 2019, ASHRAE approved June 24, 
2009.
    Copies of the American Society of Heating, Refrigerating, and Air-
Conditioning Engineers (``ASHRAE'') ANSI/ASHRAE Standard 37-2009 are 
available from the American National Standards Institute (``ANSI''), 25 
W. 43rd Street, 4th Floor, New York, NY 10036, (212) 642-4900, or 
online at: https://webstore.ansi.org/.
    ASHRAE errata sheet to ANSI/ASHRAE Standard 37-2009--Methods of 
Testing for Rating Electrically Driven Unitary Air-Conditioning and 
Heat Pump Equipment, ANSI/ASHRAE Approved March 27, 2019.
    Copies of ASHRAE errata sheet to ANSI/ASHRAE Standard 37-2009 are 
available from ASHRAE, 180 Technology Parkway NW, Peachtree Corners, GA 
30092, (404)-636-8400, or online at https://ashrae.org/.
    ISO Standard 13256-1:1998, ``Water-source heat pumps--Testing and 
rating for performance--Part 1: Water-to-air and brine-to-air heat 
pumps,'' ISO approved 1998.
    Copies of ISO Standard 13256-1:1998 can be obtained from the 
International Organization for Standardization (``ISO''), Chemin de 
Blandonnet 8 CP 401, 1214 Vernier, Geneva, Switzerland, +41 22 749 01 
11, or online at: https://webstore.ansi.org/.
    AHRI Standard 340/360-2022 (I-P), ``2022 Standard for Performance 
Rating of Commercial and Industrial Unitary Air-conditioning and Heat 
Pump Equipment,'' AHRI-approved January 26, 2022.
    Copies of AHRI Standard 340/360-2022 (I-P) can be obtained from the 
Air-Conditioning, Heating, and Refrigeration Institute (``AHRI''), 2311 
Wilson Blvd., Suite 400, Arlington, VA 22201, (703) 524-8800, or online 
at: www.ahrinet.org/search-standards.aspx.
    See section IV.M of this document for 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 of Applicability

[[Page 53303]]

    B. Definition
    C. Proposed Organization of the WSHP Test Procedure
    D. Industry Standards
    1. Applicable Industry Test Procedures
    a. ISO Standard 13256-1
    b. AHRI 340/360-2022 and ASHRAE 37-2009
    c. AHRI 600
    2. Comments Received on Industry Standards and DOE Responses
    3. Proposal for DOE Test Procedure
    E. Efficiency Metrics
    1. IEER
    a. General Discussion
    b. Determination of IEER Via Interpolation and Extrapolation
    2. COP
    a. General Discussion
    b. Determination of COP Via Interpolation
    3. Entering Air Conditions
    4. Operating Modes Other Than Mechanical Cooling and Heating
    5. Dynamic Load-Based Test Procedure
    F. Test Method
    1. Airflow and External Static Pressure
    a. Fan Power Adjustment and Required Air External Static 
Pressure
    b. Setting Airflow and ESP
    i. Ducted Units With Discrete-Step Fans
    ii. Non-Ducted Units
    2. Capacity Measurement
    a. Primary and Secondary Methods
    b. Compressor Heat
    3. Cyclic Degradation
    4. Pump Power Adjustment and Liquid External Static Pressure
    5. Test Liquid and Specific Heat Capacity
    6. Liquid Flow Rate
    a. Full-Load Cooling Tests
    b. Part-Load Cooling Tests
    c. Heating Tests
    d. Condition Tolerance
    7. Refrigerant Line Losses
    8. Airflow Measurement
    9. Air Condition Measurements
    10. Duct Losses
    11. Refrigerant Charging
    12. Voltage
    G. Configuration of Unit Under Test
    1. Specific Components
    2. Non-Standard Indoor Fan Motors
    H. Represented Values and Enforcement
    1. Multiple Refrigerants
    2. Cooling Capacity
    3. Enforcement of IEER
    I. Test Procedure Costs and Impact
    J. Compliance Date
IV. Procedural Issues and Regulatory Review
    A. Review Under Executive Orders 12866 and 13563
    B. Review Under the Regulatory Flexibility Act
    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 Public Meeting Webinar
    B. Procedure for Submitting Prepared General Statements for 
Distribution
    C. Conduct of the Public Meeting Webinar
    D. Submission of Comments
    E. Issues on Which DOE Seeks Comment
VI. Approval of the Office of the Secretary

I. Authority and Background

    Water-source heat pumps (``WSHPs'') are a category of small, large, 
and very large commercial package air-conditioning and heating 
equipment,\1\ which 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)(B)-(D)) DOE's energy 
conservation standards and test procedures for WSHPs are currently 
prescribed in title 10 of the Code of Federal Regulations (``CFR'') at 
10 CFR 431.97 and 10 CFR 431.96, respectively. The following sections 
discuss DOE's authority to establish and amend test procedures for 
WSHPs, as well as relevant background information regarding DOE's 
consideration of test procedures for this equipment.
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    \1\ The Energy Policy and Conservation Act, as amended 
(``EPCA'') defines ``commercial package air conditioning and heating 
equipment'' as air-cooled, water-cooled, evaporatively-cooled, or 
water-source (not including ground-water-source) electrically 
operated unitary central air conditioners and central air 
conditioning heat pumps for commercial application. (42 U.S.C. 
6311(8)(A)) EPCA further defines ``small commercial package air 
conditioning and heating equipment'' as commercial package air 
conditioning and heating equipment that is rated below 135,000 Btu 
per hour (cooling capacity); ``large commercial package air 
conditioning and heating equipment'' as commercial package air 
conditioning and heating equipment that is rated at or above 135,000 
Btu per hour and below 240,000 Btu per hour (cooling capacity); and 
``very large commercial package air conditioning and heating 
equipment'' as commercial package air conditioning and heating 
equipment that is rated at or above 240,000 Btu per hour and below 
760,000 Btu per hour (cooling capacity). (42 U.S.C. 6311(8)(B)-(D))
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A. Authority

    The Energy Policy and Conservation Act, as amended (``EPCA''),\2\ 
Public Law 94-163 (42 U.S.C. 6291-6317, as codified), among other 
things, authorizes DOE to regulate the energy efficiency of a number of 
consumer products and certain industrial equipment. Title III, Part C 
\3\ 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 equipment includes small, large, and very large 
commercial package air-conditioning and heating equipment, including 
WSHPs. (42 U.S.C. 6311(1)(B)-(D))
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    \2\ 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), which reflects the last statutory amendments that impact 
Parts A and A-1 of EPCA.
    \3\ For editorial reasons, upon codification in the U.S. Code, 
Part C was redesignated Part A-1.
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    The energy conservation program under EPCA consists essentially of 
four parts: (1) testing; (2) labeling; (3) Federal energy conservation 
standards, and (4) certification and enforcement procedures. Relevant 
provisions of EPCA specifically include definitions (42 U.S.C. 6311), 
energy conservation standards (42 U.S.C. 6313), test procedures (42 
U.S.C. 6314), labeling provisions (42 U.S.C. 6315), and the authority 
to require information and reports from manufacturers (42 U.S.C. 6316; 
42 U.S.C. 6296).
    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(b); 42 U.S.C. 6296), and (2) making representations about the 
efficiency of that equipment (42 U.S.C. 6314(d)). Similarly, DOE uses 
these test procedures to determine whether the equipment complies with 
relevant standards promulgated under EPCA.
    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 (b); 42 U.S.C. 6297) DOE may, however, grant waivers 
of Federal preemption for particular State laws or regulations, in 
accordance with the procedures and other provisions of EPCA. (42 U.S.C. 
6316(b)(2)(D))
    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 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))

[[Page 53304]]

    With respect to WSHPs, EPCA requires that the test procedures shall 
be those generally accepted industry testing procedures or rating 
procedures developed or recognized by the Air-Conditioning, Heating, 
and Refrigeration Institute (``AHRI'') or by the American Society of 
Heating, Refrigerating and Air-Conditioning Engineers (``ASHRAE''), as 
referenced in ASHRAE Standard 90.1, ``Energy Standard for Buildings 
Except Low-Rise Residential Buildings'' (``ASHRAE Standard 90.1''). (42 
U.S.C. 6314(a)(4)(A)) Further, if such an industry test procedure is 
amended, DOE must amend its test procedure to be consistent with the 
amended industry test procedure, unless DOE determines, by rule 
published in the Federal Register and supported by clear and convincing 
evidence, that the amended test procedure would not produce test 
results that reflect the energy efficiency, energy use, and estimated 
operating costs of that equipment during a representative average use 
cycle or would be unduly burdensome to conduct. (42 U.S.C. 
6314(a)(4)(B))
    EPCA also requires that, at least once every 7 years, DOE evaluate 
test procedures for each type of covered equipment, including WSHPs, 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. 
6314(a)(1))
    In addition, if the Secretary determines that a test procedure 
amendment is warranted, DOE 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 comments on the proposed test procedures. (42 U.S.C. 
6314(b)) If DOE determines that test procedure revisions are not 
appropriate, DOE must publish in the Federal Register its determination 
not to amend the test procedures. (42 U.S.C. 6314(a)(1)(A)(ii))
    In this notice of proposed rulemaking (``NOPR''), DOE is proposing 
amendments to the test procedures for WSHPs in satisfaction of the 7-
year-lookback obligations under EPCA. (42 U.S.C. 6314(a)(1))

B. Background

    DOE's existing test procedure for WSHPs is specified at 10 CFR 
431.96 (``Uniform test method for the measurement of energy efficiency 
of commercial air conditioners and heat pumps''). The Federal test 
procedure currently incorporates by reference International 
Organization for Standardization (``ISO'') Standard 13256-1 (1998), 
``Water-source heat pumps--Testing and rating for performance--Part 1: 
Water-to-air and brine-to-air heat pumps,'' (``ISO 13256-1:1998''). 
This is the test procedure specified by ASHRAE Standard 90.1 for water-
source heat pumps.
    DOE initially incorporated ISO 13256-1:1998 as the referenced test 
procedure for WSHPs on October 21, 2004 (69 FR 61962), and DOE last 
reviewed the test procedure for WSHPs as part of a final rule for 
commercial package air conditioners and heat pumps published in the 
Federal Register on May 16, 2012 (``May 2012 final rule''; 77 FR 
28928). In the May 2012 final rule, DOE retained the reference to ISO 
13256-1:1998 but adopted additional provisions for equipment set-up at 
10 CFR 431.96(e), which provide specifications for addressing key 
information typically found in the installation and operation manuals. 
Id at 77 FR 28991.
    On June 22, 2018, DOE published a request for information (``RFI'') 
in the Federal Register to collect information and data to consider 
amendments to DOE's test procedures for WSHPs. 83 FR 29048 (``June 2018 
RFI'').\4\ As part of the June 2018 RFI, DOE identified and requested 
comment on several issues associated with the currently applicable 
Federal test procedures, in particular concerning methods that are 
adopted through incorporation by reference of the applicable industry 
standard; efficiency metrics and calculations; additional 
specifications for the test methods; and any additional topics that may 
inform DOE's decisions in a future test procedure rulemaking, including 
methods to reduce regulatory burden while ensuring the test procedure's 
accuracy. Id.
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    \4\ An extension of the comment period for the June 2018 RFI was 
published in the Federal Register on July 9, 2018. 83 FR 31704.
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    DOE received comments in response to the June 2018 RFI from the 
interested parties listed in Table I-1.

  Table I-1--List of Commenters With Written Submissions in Response to
                            the June 2018 RFI
------------------------------------------------------------------------
                                Reference in this
         Commenter(s)                  NOPR            Commenter type
------------------------------------------------------------------------
Air-Conditioning, Heating, and  AHRI.............  IR.
 Refrigeration Institute.
Appliance Standards Awareness   Joint Advocates..  EA.
 Project, American Council for
 an Energy-Efficient Economy,
 Natural Resources Defense
 Council.
Northwest Energy Efficiency     NEEA.............  EA.
 Alliance.
Pacific Gas and Electric        CA IOUs..........  U.
 Company, San Diego Gas and
 Electric, and Southern
 California Edison;
 collectively referred to as
 the California Investor-Owned
 Utilities.
Trane Technologies............  Trane............  M.
WaterFurnace International....  WaterFurnace.....  M.
------------------------------------------------------------------------
EA: Efficiency/Environmental Advocate; IR: Industry Representative; M:
  Manufacturer; U: Utility.

    A parenthetical reference at the end of a comment quotation or 
paraphrase provides the location of the item in the public record.\5\
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    \5\ The parenthetical reference provides a reference for 
information located in the docket of DOE's rulemaking to develop 
test procedures for WSHPs. (Docket No. EERE-2017-BT-TP-0029, 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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    In May 2021, ISO published an updated version of Standard 13256-1, 
ISO Standard 13256-1 (2021), ``Water-source heat pumps--Testing and 
rating for performance--Part 1: Water-to-air and brine-to-air heat 
pumps,'' (``ISO 13256-1:2021''). ISO 13256-1:2021 is discussed further 
in section III.D of this NOPR.

II. Synopsis of the Notice of Proposed Rulemaking

    In this NOPR, DOE is proposing to amend the Federal test procedures 
for WSHPs as follows: (1) expand the scope of the test procedure to 
include WSHPs

[[Page 53305]]

with capacities between 135,000 and 760,000 British thermal units per 
hour (``Btu/h''); (2) incorporate by reference AHRI Standard 340/360-
2022 (I-P), ``2022 Standard for Performance Rating of Commercial and 
Industrial Unitary Air-conditioning and Heat Pump Equipment'' (``AHRI 
340/360-2022''), and ANSI/ASHRAE Standard 37-2009, ``Methods of Testing 
for Rating Electrically Driven Unitary Air-Conditioning and Heat Pump 
Equipment'' (``ANSI/ASHRAE 37-2009'') as the applicable test procedures 
for WSHPs, instead of the currently referenced industry test procedure 
ISO 13256-1:1998; (3) establish provisions for a new cooling efficiency 
metric, integrated energy efficiency ratio (``IEER''), for WSHPs and 
provide an alternative method of calculating IEER using interpolation 
from test conditions commonly used for WSHPs; (4) modify the test 
conditions for measuring the heating coefficient of performance 
(``COP'') and provide an alternative method of calculating COP using 
interpolation from test conditions commonly used for WSHPs; (5) include 
additional specification of setting airflow and external static 
pressure (``ESP'') for non-ducted units and ducted units with discrete-
step fans; (6) specify liquid ESP requirements for units with integral 
pumps and include a method to account for total pumping effect for 
units without integral pumps; (7) specify components that must be 
present for testing; and (8) amend certain provisions related to 
representations and enforcement in 10 CFR part 429.
    DOE proposes to implement these changes by adding new appendices C 
and C1 to subpart F of part 431, with both to be titled ``Uniform Test 
Method for Measuring the Energy Consumption of Water-Source Heat 
Pumps,'' (``appendix C'' and ``appendix C1,'' respectively). The 
current DOE test procedure for WSHPs would be relocated to appendix C 
without change, and the new test procedure adopting AHRI 340/360-2022 
and ANSI/ASHRAE 37-2009 and any other amendments would be set forth in 
proposed appendix C1 for determining IEER. As discussed elsewhere in 
this NOPR, DOE has tentatively concluded, supported by clear and 
convincing evidence, that the proposed amended test procedure in 
appendix C1 (relying on AHRI 340/360-2022 and ASHRAE 37-2009) would 
provide more representative results and more fully comply with the 
requirements of 42 U.S.C. 6314(a)(2) than testing with the current 
Federal test procedure (relying on ISO 13256-1:1998). However, use of 
proposed appendix C1 would not be required until such time as 
compliance is required with amended energy conservation standards for 
WSHPs based on IEER, should DOE adopt such standards, although a 
manufacturer would need to make any voluntary early representations of 
IEER in accordance with appendix C1.
    DOE's proposed actions are summarized in Table II-1 and addressed 
in detail in section III of this document.

 Table II-1--Summary of Changes in the Proposed Test Procedure Relative
                 to the Current Test Procedure for WSHPs
------------------------------------------------------------------------
                                     Proposed test
  Current DOE test procedure     procedure in Appendix     Attribution
                                          C1
------------------------------------------------------------------------
Scope is limited to units with  Expands the scope of    Harmonize with
 cooling capacity less than      the test procedure to   scope of test
 135,000 Btu/h.                  additionally include    procedure for
                                 units with cooling      water-cooled
                                 capacity greater than   commercial
                                 or equal to 135,000     unitary air
                                 Btu/h and less than     conditioners.
                                 760,000 Btu/h.
Incorporates by reference ISO   Incorporates by         Improve
 13256-1:1998.                   reference AHRI 340/     representativen
                                 360-2022 and ANSI/      ess of test
                                 ASHRAE 37-2009.         procedure.
Includes provisions for         Includes provisions     Improve
 determining EER metric.         for determining IEER,   representativen
                                 and specifies an        ess of test
                                 alternative method of   procedure.
                                 calculating IEER
                                 using interpolation
                                 and extrapolation
                                 from results of
                                 testing at ISO 13256-
                                 1:1998 temperatures.
Specifies test condition of 68  Changes the test        Improve
 [deg]F for measuring COP.       condition for COP to    representativen
                                 55 [deg]F and           ess of test
                                 provides an             procedure.
                                 alternative method of
                                 calculating COP using
                                 interpolation from
                                 results of testing at
                                 ISO 13256-1:1998
                                 temperatures.
Does not include specification  Includes additional     Improve
 of setting airflow and ESP      specification of        representativen
 for non-ducted units or         setting airflow and     ess of test
 ducted units with discrete-     ESP for non-ducted      procedure.
 step fans.                      units and for ducted
                                 units with discrete-
                                 step fans.
Allows for testing at any       Specifies liquid ESP    Improve
 liquid ESP with an adjustment   requirements for        representativen
 to include the pump power to    units with integral     ess of test
 overcome liquid internal        pumps, and includes a   procedure.
 static pressure.                method for accounting
                                 for the total pumping
                                 effect for units
                                 without integral
                                 pumps.
Does not include WSHP-specific  Includes provisions in  Establish WSHP-
 provisions for determination    10 CFR 429.43           specific
 of represented values in 10     specific to WSHPs to    provisions for
 CFR 429.43.                     prevent cooling         determination
                                 capacity over-rating    of represented
                                 and to determine        values.
                                 represented values
                                 for models with
                                 specific components.
Does not include WSHP-specific  Adopts product-         Establish
 enforcement provisions in 10    specific enforcement    provisions for
 CFR 429.134.                    provisions for WSHPs    DOE testing of
                                 regarding               WSHPs.
                                 verification of
                                 cooling capacity,
                                 testing of systems
                                 with specific
                                 components, and DOE
                                 IEER testing.
------------------------------------------------------------------------

    DOE has tentatively determined that the proposed amendments 
described in section III of this NOPR regarding the establishment of 
appendix C would not alter the measured efficiency of WSHPs or require 
retesting solely as a result of DOE's adoption of the proposed 
amendments to the test procedure, if made final. DOE has tentatively 
determined that the proposed test procedure amendments in appendix C1 
would, if adopted, alter the measured efficiency of WSHPs. DOE has 
tentatively determined that the proposed amendments would increase the 
cost of testing relative to the current Federal test procedure. Use of 
the proposed appendix C1 and the proposed

[[Page 53306]]

amendments to the representation requirements in 10 CFR 429.43 would 
not be required until the compliance date of amended standards 
denominated in terms of IEER, although manufacturers would need to use 
appendix C1 if they choose to make voluntary representations of IEER 
prior to the compliance date. DOE's proposed actions are discussed in 
further detail in section III of this NOPR.

III. Discussion

    In the following sections, DOE proposes certain amendments to the 
Federal test procedure for WSHPs. For each proposed amendment, DOE 
provides relevant background information, explains why the amendment 
merits consideration, discusses any relevant public comments, and 
proposes a potential approach.

A. Scope of Applicability

    This rulemaking applies to WSHPs, which are a category of small, 
large, and very large commercial package air-conditioning and heating 
equipment. (See 42 U.S.C. 6311(1)(B)-(D)) In its regulations, DOE 
defines WSHP as ``a single-phase or three-phase reverse-cycle heat pump 
that uses a circulating water loop as the heat source for heating and 
as the heat sink for cooling. The main components are a compressor, 
refrigerant-to-water heat exchanger, refrigerant-to-air heat exchanger, 
refrigerant expansion devices, refrigerant reversing valve, and indoor 
fan. Such equipment includes, but is not limited to, water-to-air 
water-loop heat pumps.'' 10 CFR 431.92.
    The current Federal test procedure and energy conservation 
standards apply to WSHPs with a rated cooling capacity below 135,000 
Btu/h. 10 CFR 431.96, Table 1 and 431.97, Table 3. However, DOE has 
identified WSHPs on the market with cooling capacities equal to or 
greater than 135,000 Btu/h.\6\ In the June 2018 RFI, DOE sought data 
and information on the size of the market for WSHPs with a cooling 
capacity over 135,000 Btu/h and any potential limitations to testing 
such units. 83 FR 29048, 29050 (June 22, 2018).
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    \6\ For simplicity in this NOPR, DOE refers to cooling capacity 
equal to or greater than 135,000 Btu/h as ``over 135,000'' Btu/h.
---------------------------------------------------------------------------

    The Joint Advocates encouraged DOE to include WSHPs over 135,000 
Btu/h within the scope of the test procedure. (Joint Advocates, No. 10 
at p. 1)
    AHRI, Trane, and WaterFurnace stated that the market for WSHPs over 
135,000 Btu/h is very small--around 0.7 percent of the market--and that 
finding a lab to test these units would be difficult for the reasons 
that follow. AHRI commented that manufacturers have limitations on the 
size of units that can be tested in their own labs, so the proposed 
expanded scope of the WSHP test procedure to encompass units with 
higher rated capacities would necessitate the use of third-party labs, 
resulting in additional costs for testing. AHRI and WaterFurnace 
further commented that WSHPs in this capacity range are highly 
customized for their application and asserted that testing them would 
incur significant costs. Trane added that no independent test labs are 
currently certified to test WSHPs over 135,000 Btu/h. (Trane, No. 8 at 
p. 2; AHRI, No. 12 at pp. 3-4; WaterFurnace, No. 7 at pp. 2-3)
    Furthermore, AHRI and WaterFurnace argued that units with capacity 
over 135,000 Btu/h are out of the scope of ISO 13256-1:1998. (AHRI, No. 
12 at p. 4; WaterFurnace, No. 7 at p.2) WaterFurnace also commented 
that AHRI certification costs would be extreme for such a small market 
due to the need to test three larger and more expensive units for 
sampling selection of each basic model group, and the likely need to 
scrap the units after testing due the significant extent of 
customization of larger units. (WaterFurnace, No. 7 at pp. 2-3)
    In response, DOE notes that contrary to the assertions of AHRI and 
WaterFurnace, no capacity limitation is expressed in ISO 13256-1:1998--
the industry standard currently incorporated by reference--or ISO 
13256-1:2021. Once again, DOE has identified numerous model lines of 
WSHPs with cooling capacity over 135,000 Btu/h from a wide variety of 
manufacturers. The manufacturer literature for all identified model 
lines includes efficiency representations that are explicitly based on 
ISO 13256-1:1998.
    Additionally, DOE is aware of several independent test labs that 
have the capability to test WSHPs with cooling capacity over 135,000 
Btu/h. DOE conducted investigative testing on multiple WSHP models with 
cooling capacity over 135,000 Btu/h at one such independent test lab 
and did not encounter any difficulties specific to units in this 
capacity range.
    Further, AHRI 340/360-2022 and ANSI/ASHRAE 37-2009 include 
provisions for testing units with capacities over 135,000 Btu/h. Both 
ASHRAE Standard 90.1 and DOE regulations cover other categories of 
commercial air conditioning and heating equipment, including water-
cooled commercial unitary air conditioners (``WCUACs''), with cooling 
capacity up to 760,000 Btu/h. DOE has tentatively determined that 
testing WSHPs with cooling capacity over 135,000 Btu/h would be of 
comparable burden to testing other commercial air conditioning and 
heating equipment of similar capacity.
    Regarding WaterFurnace's comment that an expansion of test 
procedure scope would mean that many large units would need to be 
tested, DOE notes that expanding the scope of the test procedure would 
not necessitate certification unless DOE were to establish standards 
for such equipment. Until such a time, an expansion of scope for the 
test procedure would simplify require that if manufacturers choose to 
make optional representations of WSHPs with cooling capacity over 
135,000 Btu/h, that such optional representations be made in accordance 
with the DOE test procedure. Further, representations for WSHPs can be 
made either based on testing (in accordance with 10 CFR 429.43(a)(1)) 
or based on alternative efficiency determination methods (``AEDMs'') 
(in accordance with 10 CFR 429.43(a)(2)). 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. Whereas DOE requires at least two units to be tested per basic 
model when represented values are determined through testing, DOE 
requires each AEDM to be validated by tests of only two WSHP basic 
models of any capacity (in accordance with 10 CFR 429.70(c)(2)). 
Therefore, an expansion of scope for the DOE test procedure would not 
necessitate the testing of many large units.
    For these reasons, DOE has tentatively concluded that testing units 
with cooling capacity over 135,000 Btu/h is feasible. Moreover, based 
on the presence on the market of units over 135,000 Btu/h with 
efficiency ratings and the identification of laboratories capable of 
testing such units, DOE has tentatively determined that such testing 
would not be unduly burdensome. Additionally, expanding the scope of 
DOE's test procedure for WSHPs to include equipment with cooling 
capacity between 135,000 Btu/h and 760,000 Btu/h would ensure that 
representations for all WSHPs are made using the same test procedure 
and that ratings for equipment in this cooling

[[Page 53307]]

capacity range are appropriately representative. Therefore, DOE 
proposes in this NOPR to expand the scope of applicability of the test 
procedure to include WSHPs with a cooling capacity between 135,000 and 
760,000 Btu/h. Specifically, DOE proposes to update table 1 to 10 CFR 
431.96 to include WSHPs with cooling capacity greater than or equal to 
135,000 Btu/h and less than 240,000 Btu/h under Large Commercial 
Package Air-Conditioning and Heating Equipment; and to include WSHPs 
with cooling capacity greater than or equal to 240,000 Btu/h and less 
than 760,000 Btu/h under Very Large Commercial Package Air-Conditioning 
and Heating Equipment. For both capacity ranges, the specified test 
procedure would be the proposed appendix C, and DOE proposes that any 
voluntary representations with respect to the energy use or energy 
efficiency must be made in accordance with appendix C starting 360 days 
after a test procedure final rule is published in the Federal Register. 
DOE also proposes that, starting 360 days after a test procedure final 
rule is published in the Federal Register, any voluntary 
representations of IEER must be made in accordance with the proposed 
appendix C1.
    DOE does not currently specify energy conservation standards for 
WSHPs with cooling capacity over 135,000 Btu/h. DOE would consider any 
future standards applicable to WSHPs over 135,000 Btu/h in a separate 
energy conservation standards rulemaking. Manufacturers of WSHPs with 
cooling capacity over 135,000 Btu/h would not be required to test WSHPs 
with a cooling capacity over 135,000 Btu/h until such time as 
compliance with standards for this equipment were required, should DOE 
adopt such standards, although any voluntary EER representations would 
need to be based on the test procedure in appendix C, and any voluntary 
IEER representations would need to be based on the test procedure in 
appendix C1 starting 360 days after the publication of a test procedure 
final rule. Additionally, if DOE were to adopt standards for WSHPs in 
terms of IEER, after the compliance date for those standards, any 
representations for WSHPs would be required to be made according to 
appendix C1.
    Issue 1: DOE requests comments on the proposed expansion of the 
scope of applicability of the Federal test procedure to include WSHPs 
with cooling capacity between 135,000 and 760,000 Btu/h.

B. Definition

    As discussed, WSHPs are a category of commercial package air-
conditioning and heating equipment. The current definition for ``water-
source heat pump'' does not explicitly state that it is ``commercial 
package air-conditioning and heating equipment.'' This is inconsistent 
with the definitions of most other categories of commercial package 
air-conditioning and heating equipment (e.g., computer room air 
conditioner, single package vertical air conditioner, variable 
refrigerant flow multi-split air conditioner). 10 CFR 431.92. To 
provide consistency with other definitions of specific categories of 
commercial package air-conditioning and heating equipment, DOE proposes 
to amend the definition of ``water-source heat pump'' to explicitly 
indicate that WSHPs are a category of commercial package air-
conditioning and heating equipment. This proposed clarification to the 
``water-source heat pump'' definition would not change the scope of 
equipment covered by the definition.
    In addition, DOE is proposing to amend the WSHP definition to 
clarify that an indoor fan is not an included component for coil-only 
WSHPs. The current definition lists the main components of a WSHP, and 
it includes ``indoor fan'' on that list. However, DOE has identified 
coil-only WSHPs on the market that rely on a separately installed 
furnace or modular blower for indoor air movement. To clarify that 
coil-only WSHPs are indeed covered under the WSHP definition, DOE is 
proposing to include the parenthesized statement ``except that coil-
only units do not include an indoor fan'' in the sentence listing the 
main components in the WSHP definition.
    In summary, DOE proposes to amend the definition of WSHP as 
follows:
    ``Water-source heat pump means commercial package air-conditioning 
and heating equipment that is a single-phase or three-phase reverse-
cycle heat pump that uses a circulating water loop as the heat source 
for heating and as the heat sink for cooling. The main components are a 
compressor, refrigerant-to-water heat exchanger, refrigerant-to-air 
heat exchanger, refrigerant expansion devices, refrigerant reversing 
valve, and indoor fan (except that coil-only units do not include an 
indoor fan). Such equipment includes, but is not limited to, water-to-
air water-loop heat pumps.''
    Issue 2: DOE requests comments on the proposed change to the 
definition of WSHP to explicitly indicate that WSHP is a category of 
commercial package air-conditioning and heating equipment and to 
clarify that the presence of an indoor fan does not apply to coil-only 
units.

C. Proposed Organization of the WSHP Test Procedure

    DOE is proposing to relocate and centralize the current test 
procedure for WSHPs to a new appendix C to subpart F of part 431. As 
proposed, appendix C would maintain the substance of the current test 
procedure. The test procedure as proposed in newly proposed appendix C 
would continue to reference ISO 13256-1:1998 and provide for 
determining energy efficiency ratio (``EER'') and COP. The proposed 
appendix C would centralize the additional test provisions currently 
applicable under 10 CFR 431.96, i.e., additional provisions for 
equipment set-up (10 CFR 431.96(e)). As proposed, WSHPs would be 
required to be tested according to appendix C until such time as 
compliance is required with an amended energy conservation standard 
that relies on the IEER metric, should DOE adopt such a standard.
    DOE is also proposing to establish a test procedure for WSHPs in a 
new appendix C1 to subpart F of part 431 that would incorporate by 
reference AHRI 340/360-2022 and ASHRAE 37-2009 along with additional 
provisions, as discussed in greater detail in the following sections. 
As proposed, WSHPs would not be required to test according to the test 
procedure in proposed appendix C1 until such time as compliance is 
required with an amended energy conservation standard that relies on 
the IEER metric, should DOE adopt such a standard, although any 
voluntary representations of IEER prior to the compliance date must be 
based on testing according to appendix C1.

D. Industry Standards

1. Applicable Industry Test Procedures
a. ISO Standard 13256-1
    As noted in section I.B of this document, the DOE test procedure 
currently incorporates by reference ISO 13256-1:1998 and includes 
additional provisions for equipment set-up at 10 CFR 431.96(e), which 
provide specifications for addressing key information typically found 
in the installation and operation manuals.
    ISO 13256-1:1998 specifies the cooling efficiency metric, EER,\7\ 
which is the ratio of the net total cooling capacity to the effective 
power input at

[[Page 53308]]

a single set of operating conditions. Table 1 of ISO 13256-1:1998 
specifies six sets of operating conditions for determining EER values 
based on variation in entering water temperature (``EWT'') \8\ and, for 
models with capacity control (i.e., multiple compressor stages), 
whether the test is a full-load or part-load test. The initial three 
sets, referred to as ``standard rating test'' conditions in Table 1 of 
ISO 13256-1:1998, are used to determine full-load EER values, which 
represent the cooling efficiency for a WSHP operating at its maximum 
capacity in the most demanding conditions (i.e., highest EWT) that the 
WSHP would regularly encounter. The three standard rating test 
conditions in Table 1 of ISO 13256-1:1998 differ in terms of EWT, in 
that they represent the highest EWT that would be regularly encountered 
in different specific applications (i.e., 86 [deg]F for water-loop, 59 
[deg]F for ground-water, and 77 [deg]F for ground-loop heat pumps).\9\ 
The standard rating test conditions specified for water-loop heat pumps 
are used in the current DOE test procedure.
---------------------------------------------------------------------------

    \7\ DOE defines ``EER'' at 10 CFR 431.92 as the ratio of the 
produced cooling effect of an air conditioner or heat pump to its 
net work input, expressed in BTU/watt-hour.
    \8\ ``EWT'' is used to describe the entering liquid temperature 
for WSHPs, which may be water or a brine solution, depending on the 
liquid temperature used for test.
    \9\ EWTs are specified in degrees Celsius in ISO 13256-1:1998, 
but they are referred to by their equivalent values of degrees 
Fahrenheit in this NOPR to ease comparison with other temperatures 
discussed elsewhere in this document.
---------------------------------------------------------------------------

    The next three sets of operating conditions for determining EER, 
referred to as ``part-load rating test'' conditions in Table 1 of ISO 
13256-1:1998, are specified to determine EER values at less than full 
capacity for models with capacity control. As with the standard rating 
test conditions, Table 1 of ISO 13256-1:1998 specifies part-load rating 
test conditions for different specific applications (i.e., 86 [deg]F 
for water-loop, 59 [deg]F for ground-water, and 68 [deg]F for ground-
loop heat pumps). None of the part-load rating test conditions are used 
in the current DOE test procedure. Although Table 1 of ISO 13256-1:1998 
specifies conditions for determining EER for multiple applications and 
(as applicable) capacity levels, ISO 13256-1:1998 does not include any 
seasonal cooling efficiency metrics.
    Additionally, unlike the test methods for other categories of 
commercial package air conditioners and heat pumps (e.g., AHRI 340/360-
2022 for commercial unitary air conditioners and heat pumps (``CUAC/
HPs''); AHRI Standard 1230-2021, ``2021 Standard for Performance Rating 
of Variable Refrigerant Flow (VRF) Multi-Split Air-Conditioning and 
Heat Pump Equipment'' (``AHRI 1230-2021''), for variable refrigerant 
flow air conditioners (``VRF multi-split systems''); AHRI Standard 390-
2021, ``2021 Standard for Performance Rating of Single Package Vertical 
Air-Conditioners and Heat Pumps'' (``AHRI 390-2021''), for single 
package vertical units (``SPVUs''); and AHRI Standard 210/240-2023, 
``2023 Standard for Performance Rating of Unitary Air-conditioning & 
Air-source Heat Pump Equipment'' (``AHRI 210/240-2023''), for central 
air conditioners and heat pumps (``CAC/HPs'')), for ducted units ISO 
13256-1:1998 does not produce ratings that reflect indoor fan power 
needed to overcome ESP from ductwork. Instead, section 4.1.3 of ISO 
13256-1:1998 includes a fan power adjustment (which assumes a fan 
efficiency of 0.3 for all units) to be applied such that only the fan 
power required to overcome the internal static pressure (``ISP'') of 
the unit is taken into account. The exclusion of fan power to overcome 
ESP from ductwork in ISO 13256-1:1998 ratings results in higher EER 
ratings than would be measured if ratings reflected fan power to 
overcome ESP, thereby being more representative of field applications.
    Similar to the treatment of fan power, ISO 13256-1:1998 does not 
produce ratings that reflect the pump power needed to overcome liquid 
ESP from the water loop that pipes water to and from the WSHP. Instead, 
section 4.1.4 of ISO 13256-1:1998 includes a pump power adjustment 
(which assumes a pump efficiency of 0.3 for all units) to be applied 
such that only the pump power required to overcome the liquid ISP of 
the unit is taken into account. ISO 13256-1:1998 also does not specify 
any liquid ESP requirements for testing. The exclusion of pump power to 
overcome ESP from system water loop piping in ISO 13256-1:1998 ratings 
results in higher EER ratings than would be measured if ratings 
reflected pump power to overcome ESP, thereby being more representative 
of field applications.
    An updated version of ISO Standard 13256-1 (i.e., ISO 13256-1:2021) 
was published in 2021. While there are numerous changes in ISO 13256-
1:2021 (discussed in detail in subsequent sections of this NOPR), the 
2021 version maintains provisions for determining EER, and it does not 
include provisions for determining a seasonal metric that incorporates 
tests at multiple conditions. ISO 13256-1:2021 also maintains the same 
indoor fan power adjustment and pump power adjustment as in the 1998 
version (see sections 5.1.3 and 5.1.4 of ISO 13256-1:2021), thus 
continuing to produce ratings that do not reflect fan power and pump 
power associated with overcoming ESP. As discussed in subsequent 
sections of this document, DOE is proposing provisions in its test 
procedures for WSHPs to address the identified shortcomings in ISO 
13256-1:1998 and ISO 13256-1:2021.
b. AHRI 340/360-2022 and ASHRAE 37-2009
    AHRI 340/360-2022 is the industry test procedure used for testing 
CUAC/HPs. AHRI 340/360-2022 includes the seasonal cooling metric IEER 
(see section 6.2 of AHRI 340/360-2022), which reflects cooling 
performance across a range of operating conditions and load levels. 
Specifically, IEER is a weighted average of the EER at full-load and 
several part-load conditions intended to represent the range of 
conditions that a unit would encounter over a full cooling season. The 
vast majority of operating hours for commercial air conditioners and 
heat pumps (including CUAC/HPs and WSHPs) occur when conditions are 
less demanding than full-load conditions. For example, the IEER metric 
in section 6.2.2 of AHRI 340/360-2022 specifies that full-load 
conditions account for only 2 percent of operation. AHRI 340/360-2022 
also includes minimum ESP requirements that are intended to reflect 
ESPs in field installations and includes all indoor fan power needed to 
overcome the tested ESP in the calculation of IEER (see section 6.1.3.3 
of AHRI 340/360-2022). AHRI 340/360-2022 also includes a power adder to 
account for the power of cooling tower fan motor(s) and circulating 
water pump(s). Similar to other industry test procedures for commercial 
package air-conditioning and heating equipment, AHRI 340/360-2022 
references ANSI/ASHRAE 37-2009 (see section 5.1.1 of AHRI 340/360-
2022), which provides a method of test applicable to many categories of 
air conditioning and heating equipment. In particular, sections 5 and 6 
and appendices C, D, E, and I of AHRI 340/360-2022 reference methods of 
test in ANSI/ASHRAE 37-2009. As discussed in subsequent sections of 
this notice, DOE has tentatively concluded that AHRI 340/360-2022 
addresses many of the identified shortcomings in ISO 13256-1:1998 and 
ISO 13256-1:2021.
c. AHRI 600
    AHRI is in the process of developing a new industry test standard 
for WSHPs titled ``AHRI Standard 600 IEER & SCHE Performance Rating of 
Water/Brine Source Heat Pumps'' (``AHRI 600''). This was formerly 
designated as AHRI Standard 500P (``AHRI 500P''). DOE has

[[Page 53309]]

participated in AHRI committee meetings working to develop AHRI 600 
since 2019. Based on its interactions with the AHRI committee, DOE 
understands that AHRI 600 would not include any provisions for testing, 
but rather would provide a method for calculation of a seasonal cooling 
efficiency metric for WSHPs (i.e., IEER) based on testing conducted 
according to ISO 13256-1:1998. Specifically, DOE understands that AHRI 
600 would provide for the calculation of IEER for WSHPs via 
interpolation and extrapolation of test results reflecting the testing 
temperatures specified in Table 1 of ISO 13256-1:1998, and the rating 
conditions for the IEER calculation would be based on the EWTs and 
weighting factors specified in Table 9 and section 6.2 of AHRI 340/360-
2022 for determining IEER for water-cooled CUACs. AHRI 600 is still in 
development and has not yet published. As discussed in subsequent 
sections of this notice, DOE has tentatively concluded that the general 
methodology in AHRI 600 for determining IEER is appropriate, although 
DOE has identified several aspects of the methodology that warrant 
further modifications.
2. Comments Received on Industry Standards and DOE Responses
    In the June 2018 RFI, DOE discussed how the test method used in ISO 
13256-1:1998 is similar to ANSI/ASHRAE 37-2009 and that ANSI/ASHRAE 37-
2009 is the method referenced by the 2015 version of AHRI 340/360 (the 
most current version at the time; ``AHRI 340/360-2015''). 83 FR 29048, 
29052 (June 22, 2018). DOE also discussed how AHRI 340/360-2015 is 
referenced by ASHRAE Standard 90.1 for testing WCUACs, and that DOE was 
considering whether using the same method of test for WSHPs and WCUACs 
would be appropriate, given the similarities in the design of WSHPs and 
WCUACs. Id. DOE requested comment on whether a single test method could 
be used for both WSHPs and WCUACs. Id. DOE also sought comment on any 
aspects of design, installation, and application of WSHPs that would 
make the use of ANSI/ASHRAE 37-2009 infeasible for WSHPs. Id.
    In response to the June 2018 RFI, AHRI and Trane stated that 
because ASHRAE Standard 90.1 reaffirmed the ISO 13256-1:1998 standard 
on October 26, 2018, the statutory trigger provisions of 42 U.S.C. 
6314(a)(4)(B) do not provide a basis for DOE to review its WSHP test 
procedure at that time. (AHRI, No. 12 at p. 1, Trane, No. 8 at p. 1)
    In response, DOE notes that in addition to the statutory trigger 
provisions of 42 U.S.C. 6314(a)(4)(B), the Department is statutorily 
required to review its test procedures every seven years per the 7-
year-lookback requirements at 42 U.S.C. 6314(a)(1), as outlined in 
section I.A of this NOPR.
    AHRI, WaterFurnace, and Trane recommended that DOE wait for the ISO 
revision process to be completed and adopt the revised version of ISO 
13256-1:1998 following a second RFI. (AHRI, No. 12 at p. 6; 
WaterFurnace, No. 7 at p. 2; Trane, No. 8 at p. 3) AHRI and 
WaterFurnace further commented that the next version of ISO 13256-1 was 
expected to publish in early 2019, and these commenters recommended 
that DOE should support the development of the next version of ISO 
13256-1:1998. (AHRI, No. 12 at pp. 3, 12-13; WaterFurnace, No. 7 at pp. 
2, 10) AHRI and WaterFurnace also stated that many key authors of ANSI/
ASHRAE 37-2009 are on the ISO working group, and that the working group 
was planning to add clarity to the test method with the next revision 
of ISO 13256-1:1998. The commenters also stated that minimum ESPs were 
being considered for inclusion in the revised version of ISO 13256-
1:1998. Id.
    AHRI and WaterFurnace further stated that for international 
standards, each nation requires slight deviations from the written ISO 
standard and that the AHRI WSHP/Geothermal Operations Manual \10\ 
provides the U.S. national deviations from ISO 13256-1:1998. (AHRI, No. 
12 at p. 2; WaterFurnace, No. 7 at p. 2) They further stated that the 
AHRI WSHP/Geothermal Operations Manual addresses multiple issues raised 
by DOE in the June 2018 RFI. Id.
---------------------------------------------------------------------------

    \10\ DOE notes that the AHRI geothermal operations manual is 
available at: https://www.ahrinet.org/App_Content/ahri/files/Certification/OM%20pdfs/WSHP_OM.pdf (Last accessed July 29, 2022).
---------------------------------------------------------------------------

    In response, DOE notes that ISO 13256-1:2021 also lacks a seasonal 
cooling efficiency metric and does not produce ratings that reflect fan 
power and pump power associated with overcoming ESP. As discussed, a 
seasonal cooling efficiency metric would account for the range of 
conditions that a unit would encounter over a full cooling season. In 
addition, the inclusion of fan and pump power associated with 
overcoming ESP would provide ratings that would be more representative 
of the power consumption in field applications needed to overcome 
pressure from ductwork and water piping. Section III.D.3 of this 
document provides further discussion of these considerations and DOE's 
preliminary conclusion that alternate test methods that address these 
key issues would provide a more representative measure of a WSHP's 
overall energy efficiency.
    While an updated version of ISO Standard 13256-1 has published 
(i.e., ISO 13256-1:2021), DOE is not aware of a deviation process being 
initiated for the U.S. (i.e., development of the version designated 
with ``AHRI/ASHRAE'' that is intended for use for testing in the U.S.). 
DOE understands that the national deviation process will be initiated 
by a WSHP industry committee, but DOE does not know when that will 
begin or how long the national deviation process will take. DOE notes 
that in the past, the WSHP industry committees have taken years longer 
than expected to develop the revised version of ISO 13256-1, as well as 
AHRI 600. Specifically, in their RFI comments, AHRI and WaterFurnace 
stated that they expected the revised ISO 13256-1 to publish in ``early 
2019'' and AHRI 600 to publish in 2019, whereas in reality, the revised 
ISO 13256-1 published in 2021 and AHRI 600 remains as yet unpublished. 
Therefore, DOE expects that the national deviation process will not be 
completed for several years, and the Department cannot speculate as to 
the substantive output of those efforts or a final completion date. 
Given EPCA's statutory requirement to review the appropriate test 
procedures for WSHPs every seven years, DOE has tentatively concluded 
that it would be neither appropriate nor permissible to delay the 
current rulemaking for the WSHP test procedure until after the 
completion of the national deviation process (which the Department 
understands has not yet even begun).
    DOE further notes that the AHRI WSHP/Geothermal Operations Manual 
is not incorporated by reference into the DOE test procedure, nor is it 
referenced in ASHRAE Standard 90.1. Therefore, the deviations from the 
ISO standard included in the AHRI WSHP/Geothermal Operations Manual are 
not reflected in the current DOE test procedure. However, DOE has 
nonetheless reviewed the AHRI WSHP/Geothermal Operations Manual as part 
of its consideration of potential amended test procedure provisions in 
this NOPR.
    With regards to use of a part-load efficiency metric, Trane, AHRI, 
and WaterFurnace commented that industry is currently developing an 
IEER metric for WSHPs. (Trane, No. 8 at p. 4; AHRI, No. 12 at p. 11; 
WaterFurnace, No. 7 at p. 9) AHRI and WaterFurnace commented further 
that the IEER metric

[[Page 53310]]

is included in the draft of AHRI 500P \11\ and is calculated using 
performance data from ISO 13256-1:1998. In addition, AHRI and 
WaterFurnace stated that WSHPs in water-loop applications (i.e., 
installed with cooling towers) operate with similar water-loop 
conditions to WCUACs. Therefore, the commenters argued that the 
provisions used for determining IEER for WSHPs in the draft of AHRI 
500P are similar to those included in AHRI 340/360 and AHRI 1230; 
specifically, the commenters included a table showing that the IEER EWT 
conditions in the draft of AHRI 500P align with those specified in AHRI 
340/360. Both AHRI and WaterFurnace commented that they anticipated 
AHRI 500P to be completed in 2019. (AHRI, No. 12 at pp. 11-12; 
WaterFurnace, No. 7 at p. 9)
---------------------------------------------------------------------------

    \11\ As discussed, after DOE received comments in response to 
the June 2018 RFI, the draft AHRI Standard 500P was redesignated as 
the draft AHRI Standard 600.
---------------------------------------------------------------------------

    Once again, DOE notes that AHRI 600 \12\ has not yet published, and 
the Department is unaware as to when that document will be completed. 
Accordingly, for this NOPR, in addition to proposing a method to 
determine IEER by testing at the IEER test points specified in Table 9 
of AHRI 340/360-2022, DOE is proposing an alternate method of 
calculating IEER (based on interpolation and extrapolation from results 
of testing to EWTs specified in Table 1 of ISO 13256-1:1998, rather 
than testing directly at the EWTs specified for the IEER metric in 
Table 9 of AHRI 340/360-2022) that DOE understands to be consistent 
with the approach in the current draft version of AHRI 600. Section 
III.E.1.b of this NOPR includes further details on the proposed 
optional approach for calculation of IEER based on interpolation and 
extrapolation.
---------------------------------------------------------------------------

    \12\ As discussed, after DOE received comments in response to 
the June 2018 RFI, the draft AHRI Standard 500P was redesignated as 
the draft AHRI Standard 600.
---------------------------------------------------------------------------

    DOE also received comments from AHRI, Trane, and WaterFurnace that 
cautioned against using a different test standard, such as AHRI 340/
360, for testing WSHPs instead of ISO 13256-1 as currently specified. 
(Trane, No. 8 at p. 4; AHRI, No. 12 at p. 12; WaterFurnace, No. 7 at p. 
10) AHRI, Trane, and WaterFurnace argued that AHRI 340/360 does not 
include several important features that are included in ISO 13256-
1:1998 such as: provisions for heating performance, performance mapping 
\13\ across a wide temperature range, part-load ratings, application 
ratings for well water and geothermal, and provisions for testing units 
with variable-speed compressors. (Trane, No. 8 at p. 4; AHRI, No. 12 at 
p. 12; WaterFurnace, No. 7 at p. 10) Trane stated that AHRI 340/360 
covers only cooling-mode operation of water-cooled units, and that 
WSHPs require a test procedure that includes both cooling and heating 
cycle operation. (Trane, No. 8 at p. 4) AHRI and WaterFurnace 
additionally stated that certain aspects of ISO 13256-1:1998, such as 
standard rating conditions, are not included in ANSI/ASHRAE 37-2009 
because ANSI/ASHRAE 37-2009 is a method of test rather than a test 
standard. (AHRI, No. 12 at pp. 12-13; WaterFurnace, No. 7 at pp. 10-11) 
AHRI, Trane, and WaterFurnace further commented that that many aspects 
of ANSI/ASHRAE 37-2009 are accounted for in ISO 13256-1:1998. (AHRI, 
No. 12 at p. 13; Trane, No. 8 at p. 4; WaterFurnace, No. 7 at p. 10) 
AHRI and WaterFurnace also stated that several Environmental Protection 
Agency (``EPA''), State, utility, and building code requirements 
reference ISO 13256-1:1998, and they asserted that removing reference 
to it would have a significant negative impact on the industry and 
consumers who use efficiency programs and tax credits when selecting 
equipment. (AHRI, No. 12 at p. 12; WaterFurnace, No. 7 at p. 10)
---------------------------------------------------------------------------

    \13\ DOE understands use of the term ``performance mapping'' as 
referring to making representations of performance across a range of 
temperature conditions, typically achieved by interpolating or 
extrapolating from test results obtained at specifically defined 
test conditions.
---------------------------------------------------------------------------

    The following paragraphs provide DOE's responses to concerns 
expressed by commenters that AHRI 340/360 and ANSI/ASHRAE 37-2009 lack 
certain provisions that are present in ISO 13256-1 and that are needed 
for testing WSHPs.
    Regarding provisions for heating tests, DOE acknowledges that AHRI 
340/360-2022 does not include certain provisions needed for heating-
mode testing of WSHPs because WCUACs, the water-cooled units for which 
AHRI 340/360-2022 is intended to apply, are not heat pumps. 
Specifically, AHRI 340/360-2022 does not specify the following 
provisions for a heating test: an EWT test condition, provisions for 
setting liquid flow rate, or how pump effects are accounted for. 
Therefore, DOE is proposing additional provisions that would address 
these aspects of heating-mode tests of WSHPs, as discussed further in 
sections III.E.2, III.F.4, III.F.5, and III.F.6 of this document. DOE 
notes that AHRI 340/360-2022 does include provisions appropriate for 
air-side measurements in heating tests because AHRI 340/360-2022 covers 
air-cooled commercial unitary heat pumps. Furthermore, ANSI/ASHRAE 37-
2009 provides appropriate provisions for a method of test for WSHPs. 
DOE has tentatively concluded that its proposals for heating provisions 
for WSHPs would, when combined with the provisions in AHRI 340/360-
2022, produce test results representative of an average use cycle.
    Regarding performance mapping across a wide temperature range, 
part-load ratings, and ratings for ground-water and geothermal 
applications, DOE acknowledges that AHRI 340/360-2022 does not include 
EWTs specific to multiple applications of WSHPs. By contrast, Table 1 
of ISO 13256-1:1998 provides separate EWTs for water-loop, ground-
water, and ground-loop WSHP applications (see discussion in section 
III.D.1.a of this NOPR). AHRI 340/360-2022 includes full-load and part-
load cooling EWTs for only water-loop applications of WCUACs, but the 
EWT for water-loop applications in Table 1 of ISO 13256-1:1998 is the 
only EWT test condition used in the current DOE test procedure. As 
discussed in sections III.D.3 and III.E.1 of this NOPR, DOE has 
tentatively concluded that the seasonal integrated cooling metric IEER 
specified in section 6.2 of AHRI 340/360-2022 would be more 
representative of field applications and provide consumers with a 
better understanding of year-round performance of WSHPs than the EER 
metric measured at a single temperature and load level. However, DOE 
recognizes the potential benefits to consumers of allowing 
manufacturers to continue to provide performance ratings at the 
temperatures and load levels specified in Table 1 of ISO 13256-1:1998, 
in addition to providing the proposed IEER ratings which are more 
representative of year-round performance. Therefore, as discussed in 
section III.E.1.a of this NOPR, DOE is proposing in section 5.2 of 
proposed appendix C1 to provide for optional representations of EER at 
the EWTs and load levels specified in Table 1 of ISO 13256-1:1998. 
Consequently, DOE has tentatively concluded that the proposals in this 
NOPR would continue to provide manufacturers the flexibility to offer 
full-load and part-load EER ratings at multiple temperatures that can 
be used for performance mapping, representations of part-load 
performance, and representations of performance for ground-water and 
geothermal applications.
    Regarding variable-speed compressors, section 6.2 of AHRI 340/360-
2022 includes appropriate provisions for testing and determining IEER 
for units with all compressor

[[Page 53311]]

types, including variable-speed compressors. Specifically, Section 
6.2.6 of AHRI 340/360-2022 includes provisions addressing 
``proportionally capacity controlled units,'' which is defined in 
section 3.22 of AHRI 340/360-2022 to include units incorporating one or 
more variable-capacity compressors where the compressor capacity can be 
modulated continuously or in steps not more than 5 percent of the full-
load cooling capacity. Section 6.2.6 of AHRI 340/360-2022 includes 
steps for setting capacity of these units for each IEER test point.
    With regards to EPA, State, utility, and building code requirements 
that reference ISO 13256-1:1998, DOE does not expect that an update to 
the DOE test procedure for WSHPs would create any particular challenges 
for any other agency or organization that references the performance 
ratings as measured by the DOE test procedure. EPCA directs DOE to 
establish and amend test procedures to be reasonably designed to 
produce test results which reflect energy efficiency, energy use, and 
estimated operating costs of covered equipment during a representative 
average use cycle (as determined by the Secretary), and not be unduly 
burdensome to conduct. (42 U.S.C. 6314(a)(2)) DOE test procedures are 
updated regularly, across many products and equipment types, and other 
agencies and organizations have historically updated their requirements 
as needed in response to those changes. With regard to EPA 
specifically, DOE has responsibility for developing and revising the 
test procedures that provide the basis for ratings under EPA's ENERGY 
STAR program. DOE and EPA work closely together to update ENERGY STAR 
specifications in response to any changes to the relevant DOE test 
procedure. Furthermore, DOE is proposing that the amended test 
procedure would not be required for use until the effective date of any 
future energy conservation standards based on the IEER metric, thereby 
providing sufficient advance notice for any agency or organization to 
adapt program requirements accordingly.
3. Proposal for DOE Test Procedure
    As discussed, EPCA requires that test procedures for covered 
equipment, including WSHPs, be reasonably designed to produce test 
results which reflect energy efficiency, energy use, and estimated 
operating costs of a type of industrial equipment (or class thereof) 
during a representative average use cycle (as determined by the 
Secretary), and shall not be unduly burdensome to conduct. (42 U.S.C. 
6314(a)(2))
    For the reasons presented in the remainder of this section, DOE has 
tentatively determined that the test procedure for WSHPs as proposed 
would improve the representativeness of the current Federal test 
procedure for WSHPs and would not be unduly burdensome. Specifically, 
DOE has tentatively concluded, supported by clear and convincing 
evidence as discussed in the following paragraphs, that testing WSHPs 
in accordance with the industry test standards AHRI 340/360-2022 and 
ASHRAE 37-2009 would provide more representative results and more fully 
comply with the requirements of paragraph (2) of 42 U.S.C. 6314(a) than 
testing in accordance with the currently referenced standard ISO 13256-
1:1998. Therefore, DOE is proposing to amend the test procedure for 
WSHPs so as to incorporate by reference in the proposed new appendix C1 
the test provisions in AHRI 340/360-2022 and ASHRAE 37-2009, along with 
certain additional provisions.
    Throughout the remainder of the discussion in section III of this 
NOPR, DOE presents the details and justifications for the proposed test 
procedure and deviation from the currently referenced industry test 
procedure, ISO 13256-1:1998 (i.e., the industry test standard 
referenced in ASHRAE Standard 90.1). The following paragraphs summarize 
the key areas in which DOE has tentatively concluded, supported by 
clear and convincing evidence, that the proposal would improve the 
representativeness of the test procedure:
    (1) Cooling efficiency metric: As discussed, the cooling metric 
specified in the current DOE test procedure (which references ISO 
13256-1:1998) is EER, which reflects full-load performance only at a 
single operating condition. In contrast, IEER, the metric specified in 
section 6.2 of AHRI 340/360-2022, is a seasonal metric that is a 
weighted average of the full- and part-load performance at different 
outdoor conditions intended to represent average efficiency over a full 
cooling season. For the vast majority of operating hours for WSHPs and 
other commercial air conditioners and heat pumps installed in the 
field, loads are at less than full-load capacity. This is because units 
are sized to be able to provide sufficient air conditioning capacity at 
the hottest time on the hottest day of the year, but the vast majority 
of annual cooling hours are at significantly lower outdoor temperatures 
(and thus lower EWTs), with correspondingly lower cooling loads. This 
is demonstrated in the IEER metric specified in section 6.2.2 of AHRI 
340/360-2022, which specifies a weighting factor for full-load 
conditions of only 2 percent of the hours included in the IEER metric, 
with the remaining 98 percent of hours assigned to lower load levels 
and lower outdoor temperatures. As discussed, from RFI comments and 
DOE's participation in AHRI 600 committee meetings, DOE understands 
that the AHRI 340/360-2022 IEER weighting factors are also included in 
the draft AHRI 600. Therefore, DOE has tentatively concluded that IEER 
would be more representative of an average use cycle than the EER 
metric. This topic is discussed further in section III.E.1 of this 
NOPR.
    (2) Fan power and indoor air external static pressure: As 
discussed, for ducted units, ISO 13256-1:1998 does not produce ratings 
that reflect the fan power needed to overcome ESP. Further, that ISO 
standard does not specify ESP requirements for ducted units and instead 
uses a fan power adjustment, such that ratings reflect only the fan 
power needed to overcome internal static pressure within the unit and 
not the ESP from the ductwork that would be installed in the field. In 
contrast, Table 7 of AHRI 340/360-2022 specifies minimum ESP 
requirements at which performance is measured. Because ducted WSHPs are 
manufactured to be installed in the field with ductwork, DOE has 
tentatively concluded that a WSHP rating that reflects the indoor fan 
power needed to overcome ESP representative of typical installations 
(i.e., the approach taken by AHRI 340/360-2022) would produce test 
results that are more representative of an average use cycle than 
testing in accordance with ISO 13256-1:1998, the standard currently 
incorporated by reference.
    (3) Pump power and liquid external static pressure: ISO 13256-
1:1998 does not produce ratings that reflect the pump power needed to 
overcome liquid ESP. Further, for units with integral pumps, ISO 13256-
1:1998 does not specify ESP requirements and uses a pump power 
adjustment such that ratings reflect only the pump power needed to 
overcome internal static pressure within the unit. For units with 
integral pumps, DOE has tentatively concluded that ratings would be 
more representative if based on testing at a liquid ESP that is 
representative of the ESP from water piping in typical installations. 
For units without integral pumps, DOE has tentatively concluded that 
ratings would be more

[[Page 53312]]

representative if a pump power adder is included in the rating that 
reflects pump power needed to overcome a field-representative liquid 
ESP. More discussion on this topic is provided in section III.F.4 of 
this document.
    DOE is proposing to adopt in its WSHP test procedure the following 
specific sections of AHRI 340/360-2022:

    (1) Section 3: Definitions, excluding sections 3.2, 3.4, 3.5, 
3.7, 3.8, 3.12, 3.14, 3.15, 3.17, 3.23, 3.26, 3.27, 3.29, 3.30, and 
3.36;
    (2) Section 5: Test Requirements;
    (3) Section 6: Rating Requirements, excluding sections 6.1.1.7, 
6.1.2.1, 6.1.3.4.5, 6.1.3.5.4, 6.1.3.5.5, 6.5, 6.6, and 6.7;
    (4) Appendix A. References--Normative;
    (5) Appendix C. Indoor and Outdoor Air Condition Measurement--
Normative;
    (6) Appendix E. Method of Testing Unitary Air Conditioning 
Products--Normative;

    The key substantive changes that would result from DOE's proposal 
to adopt AHRI 340/360-2022 for testing WSHPs include the following:

    (1) A new energy efficiency descriptor, IEER, which incorporates 
part-load cooling performance (see section 6.2 of AHRI 340/360-
2022);
    (2) Minimum ESP requirements, instructions for setting airflow 
and ESP, and tolerances for airflow and ESP (see sections 6.1.3.3, 
6.1.3.4, and Table 6 of AHRI 340/360-2022);
    (3) Fixed inlet and outlet water temperature conditions (see 
Table 5 of AHRI 340/360-2022);
    (4) Operating tolerance for voltage (see Table 10 of AHRI 340/
360-2022);
    (5) Different indoor air conditions used for testing (see Table 
5 of AHRI 340/360-2022);
    (6) Refrigerant charging instructions for cases where they are 
not provided by the manufacturer (see section 5.8 of AHRI 340/360-
2022), and
    (7) Use of the primary capacity measurement (i.e., indoor air 
enthalpy method) as the value for capacity, and different provisions 
for required agreement between primary and secondary capacity 
measurements (see section E6 of Appendix E to AHRI 340/360-2022).

    Appendix E of AHRI 340/360-2022 specifies the method of test, 
including the use of specified provisions of ANSI/ASHRAE 37-2009. 
Consistent with AHRI 340/360-2022, DOE is proposing to incorporate by 
reference ANSI/ASHRAE 37-2009 in its test procedure for WSHPs. 
Specifically, in section 1 of the proposed test procedure for WSHPs in 
the proposed appendix C1, DOE is proposing to adopt all sections except 
sections 1, 2, and 4 of ANSI/ASHRAE 37-2009. The key substantive 
changes that would result from DOE's proposal to adopt ANSI/ASHRAE 37-
2009 for testing WSHPs include the following:

    (1) Provisions for split systems, such as accounting for 
compressor heat and refrigerant line losses (see sections 7.3.3.4, 
7.3.4.4, and 7.6.1.2 of ASHRAE 37-2009);
    (2) Measurement of duct losses for ducted units (see section 
7.3.3.3 of ASHRAE 37-2009);
    (3) Standardized heat capacity of water and brine (see section 
12.2 of ASHRAE 37-2009), and
    (4) A calculation for discharge coefficients (see section 6.3.2 
of ASHRAE 37-2009).

    Throughout the remainder of this NOPR, DOE discusses substantive 
differences between the proposed test procedure (including references 
to AHRI 340/360-2022 and ASHRAE 37-2009) and the current DOE test 
procedure (which incorporates by reference ISO 13256-1:1998). DOE also 
identified and considered provisions in the updated industry test 
procedure ISO 13256-1:2021 that substantively differ from ISO 13256-
1:1998.

E. Efficiency Metrics

1. IEER
a. General Discussion
    As discussed previously, DOE's current test procedure for WSHPs 
measures cooling-mode performance in terms of the EER metric, the 
current regulatory metric. 10 CFR 431.96. EER captures WSHP performance 
at a single, full-load operating point in cooling mode (i.e., a single 
EWT) and does not provide a seasonal or load-weighted measure of energy 
efficiency. A seasonal metric is a weighted average of the performance 
of cooling or heating systems at different outdoor conditions intended 
to represent average efficiency over a full cooling or heating season. 
Several categories of commercial package air-conditioning and heating 
equipment are rated using a seasonal or part-load metric, such as IEER 
for CUACs specified in section 6.2 of AHRI 340/360-2022. IEER is a 
weighted average of efficiency at four load levels representing 100, 
75, 50, and 25 percent of full-load capacity, each measured at a 
specified outdoor condition that is representative of field operation 
at the given load level. In general, the IEER metric provides a more 
representative measure of field performance than EER by weighting the 
full-load and part-load efficiencies by the average amount of time 
equipment spends operating at each load level. Table 1 of ISO 13256-
1:1998, the industry test standard incorporated by reference into DOE's 
current WSHP test procedure, and Table 2 of ISO 13256-1:2021 both 
specify entering water temperature conditions to be used for developing 
part-load ratings of EER for WSHPs with capacity control (tested at 
minimum compressor speed). However, part-load EER ratings are not 
addressed in the current DOE test procedure. Further, each part-load 
rating captures operation only at a single compressor speed and 
entering water temperature, not operation across a range of 
temperatures and compressor speeds. Neither ISO 13256-1:1998 nor ISO 
13256-1:2021 include seasonal metrics.
    In the June 2018 RFI, DOE requested comment on whether a seasonal 
metric that accounts for part-load performance would be appropriate for 
WSHPs, and the Department sought information on the specific details of 
a seasonal metric that would best represent average cooling efficiency 
for WSHPs. 83 FR 29048, 29051 (June 22, 2018).
    NEEA encouraged DOE to consider adopting IEER for WSHPs and to 
improve the metric so as to make it more representative of an average 
use cycle by including changes to more accurately represent fan energy 
use in field applications, accounting for all modes of operation, and 
including ventilating and economizing. (NEEA, No. 11 at p. 2)
    The Joint Advocates recommended that DOE should consider seasonal 
efficiency metrics for WSHPs to better reflect field energy 
consumption, including part-load operation. The Joint Advocates stated 
that it was their understanding that WSHPs operate most of the time at 
part-load, and that, therefore, full-load efficiency ratings do not 
provide sufficient information to consumers. The Joint Advocates also 
stated that the current metrics do not demonstrate the potential 
savings associated with technologies that improve part-load efficiency, 
such as variable-speed compressors. (Joint Advocates, No. 10 at p. 2)
    The CA IOUs stated that while the IEER metric provides a valuable 
measure of annual efficiency, the EER metric is important for achieving 
reductions in peak loads. These commenters remarked that because the 
IEER metric uses a low weighting (i.e., 2 percent) for the full-load 
condition, a standard based only on the IEER metric would incentivize 
manufacturers to optimize equipment at the part-load conditions and 
could potentially result in equipment that is designed with lower full-
load EERs than the current standards for this equipment. To prevent 
poor equipment performance at full-load conditions, the CA IOUs 
supported using the IEER metric that measures part-load efficiencies in 
conjunction with the currently regulated full-load EER metric. (CA 
IOUs, No. 9 at pp. 1-2) The CA IOUs further commented that the 
prevalence of economizers in buildings with WSHPs

[[Page 53313]]

should be investigated and that modifications to the IEER metric should 
be informed by the outcome of such research before the IEER metric is 
implemented as the efficiency metric for WSHPs. (CA IOUs, No. 9 at p. 
1)
    Trane, AHRI, and WaterFurnace commented that industry is currently 
developing an IEER metric for WSHPs (Trane, No. 8 at p. 4; AHRI, No. 12 
at p. 11; WaterFurnace, No. 7 at p. 9). AHRI and WaterFurnace explained 
further that the IEER metric is included in the draft version of AHRI 
500P,\14\ and as drafted, IEER is calculated using performance data 
from ISO 13256-1:1998. AHRI and WaterFurnace commented that the 
provisions used for determining IEER for WSHPs in the draft version of 
AHRI 500P are similar to those included in AHRI 340/360 and AHRI 1230. 
Both AHRI and WaterFurnace commented that they anticipated AHRI 500P to 
be completed in 2019. (AHRI, No. 12 at p. 11; WaterFurnace, No. 7 at p. 
9)
---------------------------------------------------------------------------

    \14\ As discussed, after DOE received comments in response to 
the June 2018 RFI, the draft AHRI Standard 500P was redesignated as 
the draft AHRI Standard 600.
---------------------------------------------------------------------------

    As explained previously, DOE notes that the EER metric in DOE's 
current test procedure for WSHPs measures only full-load performance, 
and the revised industry test procedure ISO 13256-1:2021 does not 
include a seasonal metric. For the vast majority of operating hours of 
WSHPs installed in the field, loads are less than full-load capacity, 
thus causing single-stage WSHPs to cycle and multi-stage WSHPs to 
operate at part-load (i.e., less than designed full capacity). Because 
a seasonal metric reflects operation at a range of conditions 
experienced over the period of a cooling season, DOE has tentatively 
concluded that a cooling metric that accounts for part-load performance 
across a range of temperatures (such as IEER specified in section 6.2 
of AHRI 340/360-2022) would be more representative of an average use 
cycle than the full-load EER metric, which reflects operation at a 
single condition. Further, a seasonal metric that reflects varying load 
levels representative of a full cooling season would better incentivize 
use of modulating components (e.g., multi-stage and variable-speed 
compressors) that can reduce annual energy consumption in field 
installations.
    DOE has been participating in AHRI committee meetings to develop 
AHRI 600 with the goal of specifying an IEER metric for WSHPs. It is 
DOE's understanding that the committee's work is ongoing, and its 
completion date is uncertain. However, based on comments received on 
the June 2018 RFI, manufacturer feedback obtained via DOE's 
participation in AHRI 600 committee meetings, and DOE's own research, 
the Department has tentatively concluded that the EWTs and weighting 
factors specified in Table 9 and equation 3 of AHRI 340/360-2022 for 
water-cooled CUACs would be representative for WSHPs. DOE's 
understanding based on a review of market literature and available 
studies is that in the past, WSHP installations were more typically 
controlled such that water-loop temperatures were maintained at 
temperatures above 60 [deg]F through heat provided by a system boiler. 
From manufacturer feedback provided in AHRI 600 committee meetings, DOE 
understands that in current practice, WSHP installations are typically 
controlled to allow water-loop temperatures to drop to temperatures 
closer to 50 [deg]F. Manufacturers indicated that this change in how 
WSHP system loops are typically controlled in the field is because of 
multiple factors. One factor provided by manufacturers is that because 
commercial buildings with WSHP installations are typically cooling-
dominated (i.e., most WSHPs spend more time in cooling mode than 
heating mode), building engineers have increasingly optimized overall 
WSHP system performance by using the cooling tower to decrease EWTs 
below 60 [deg]F even when some WSHPs in the loop are in heating mode, 
thereby improving efficiency for the WSHPs in cooling mode at the 
expense of reducing efficiency for the fewer WSHPs in heating mode. 
Additionally, manufacturers indicated that the market penetration of 
WSHPs with water-side economizers has significantly increased in recent 
years, largely related to requirements in ASHRAE Standard 90.1 
regarding presence of economizers in HVAC systems. Water-side 
economizers provide compressor-free cooling when supplied with water of 
sufficiently low temperature; therefore, manufacturers have indicated 
that building engineers are increasingly maintaining WSHP loop 
temperatures below 60 [deg]F to take advantage of water-side economizer 
cooling.\15\ Given this feedback provided by manufacturers on the WSHP 
loop water temperatures typically used in the field, DOE has 
tentatively concluded that the IEER EWTs specified in Table 9 of AHRI 
340/360-2022 (i.e., 85 [deg]F, 73.5 [deg]F, 62 [deg]F, and 55 [deg]F) 
are representative of current installations of WSHPs. Section III.E.4 
of this NOPR includes discussion on other operating modes other than 
mechanical cooling and heating, such as ventilation and economizing.
---------------------------------------------------------------------------

    \15\ In WSHPs with water-side economizers, if the EWT is 
sufficiently low in cooling mode, some or all of the entering water 
that would otherwise enter the water-to-refrigerant condenser coil 
instead enters the economizer coil, in which the cool water is used 
to directly cool indoor air, reducing the need for mechanical 
cooling from the compressor.
---------------------------------------------------------------------------

    Based on the discussion in the preceding paragraphs, DOE has 
tentatively determined that use of a seasonal efficiency metric, 
specifically IEER based on AHRI 340/360-2022, would be more 
representative of the average use cycle of a unit as compared to the 
current EER metric. Once again, DOE notes that while it may have been 
expected that AHRI 600 was to publish in 2019, the draft standard has 
not yet been finalized. Accordingly, DOE is moving forward and 
proposing to adopt certain provisions of AHRI 340/360-2022 and use the 
IEER metric specified in section 6.2 of AHRI 340/360-2022 for WSHPs. 
DOE is proposing to specify the relevant test procedure requirements 
for WSHPs for measuring IEER in section 5.1 of proposed appendix C1.
    As discussed, the proposed IEER test procedure for WSHPs would not 
be required until such a time as DOE adopts energy conservation 
standards for WSHPs denominated in terms of IEER, should DOE adopt such 
standards. If DOE were to adopt such standards, such shift to the IEER 
metric for WSHPs would require all WSHPs to be re-rated in terms of the 
IEER metric. Further, beginning 360 days after final rule publication, 
manufacturers would be required to use the proposed test procedure in 
appendix C1 to make optional representations of IEER for WSHPs. The 
cost and impacts to manufacturers of the proposed test procedure are 
discussed further in section III.I of this document. Additionally, 
adopting the IEER metric for WSHPs would increase the number of 
required cooling-mode tests from one to four. However, as discussed, 
DOE understands that AHRI 600 would provide for calculating IEER from 
test results measured at the EWTs specified in Table 1 of ISO 13256-
1:1998. Consistent with this approach and as discussed in the following 
section, DOE is proposing to allow determination of IEER via 
interpolation and extrapolation from testing at the full-load and part-
load EWT conditions specified in Table 1 of ISO 13256-1:1998.

[[Page 53314]]

    In response to the CA IOUs' suggestion, although EPCA limits the 
agency to promulgation of a single performance standard (see 42 U.S.C. 
6311(18)), DOE is proposing to provide for optional representations of 
EER conducted per the proposed test procedure (sections 2 through 4 and 
7 of proposed appendix C1) at the full-load and part-load EWT 
conditions specified in Table 1 of ISO 13256-1:1998 (i.e., full load 
tests at 86 [deg]F, 77 [deg]F, and 59 [deg]F and part-load tests at 86 
[deg]F, 68 [deg]F, and 59 [deg]F).
    Issue 3: DOE requests comment on its proposal to adopt the test 
methods specified in AHRI 340/360-2022 for calculating the IEER of 
WSHPs. DOE also requests comment on its proposal that all EER tests at 
full-load and part-load conditions specified in Table 1 of ISO 13256-
1:1998 (i.e., full-load tests at 86 [deg]F, 77 [deg]F, and 59 [deg]F 
and part-load tests at 86 [deg]F, 68 [deg]F, and 59 [deg]F) are 
optional.
b. Determination of IEER Via Interpolation and Extrapolation
    As discussed, DOE understands that the draft AHRI 600 would provide 
a mechanism for calculating IEER from test results measured at the EWTs 
specified in Table 1 of ISO 13256-1:1998. Specifically, interpolation 
and extrapolation \16\ from ISO 13256-1:1998 test results would be used 
to calculate performance at the EWTs specified in Table 9 of AHRI 340/
360-2022 for WCUACs, allowing calculation of IEER for WSHPs using the 
weighting factors specified in section 6.2.2 of AHRI 340/360-2022. 
Under this approach, AHRI 600 would not include any provisions for 
testing, but rather would provide a method for calculation of IEER 
based on results of testing under ISO 13256-1:1998. DOE recognizes that 
there may be a value for stakeholders in representations of full-load 
and part-load EER ratings at the temperatures specified in Table 1 of 
ISO 13256-1:1998. Specifically, these EWTs represent different 
applications, and manufacturers may prefer to provide representations 
of performance specific to different applications.
---------------------------------------------------------------------------

    \16\ Per the draft AHRI 600 method, performance at IEER EWTs can 
be determined using test results at two different temperature 
conditions (specified in ISO 13256-1:1998). Interpolation is used if 
the IEER EWT is between the two tested EWTs, and extrapolation is 
used if the IEER EWT is outside the range of the two tested results.
---------------------------------------------------------------------------

    The ability to determine EER ratings at the ISO 13256-1:1998 EWTs 
(in accordance with the proposed test procedure, at section 5.2 of the 
proposed appendix C1), and to determine IEER via interpolation and 
extrapolation from testing at the ISO 13256-1:1998 EWTs, rather than 
from additional testing at the IEER EWTs specified in AHRI 340/360-
2022, may reduce overall testing burden for manufacturers. 
Consequently, DOE investigated the AHRI 600 method of calculating IEER.
    To evaluate the draft AHRI 600 method of calculating IEER, DOE 
conducted investigative testing on a sample of WSHPs. DOE presents the 
results of testing 15 WSHPs in the following paragraphs. This testing 
compared the interpolation and extrapolation method of calculating IEER 
at the ISO 13256-1:1998 EWTs to testing at the IEER EWTs specified in 
AHRI 340/360-2022. In summary and for the reasons discussed in the 
following paragraphs, DOE has tentatively determined that an 
interpolation and extrapolation approach, similar to that in draft AHRI 
600 with certain modifications, is appropriately representative to 
calculate IEER.
    To determine if the interpolation and extrapolation method is 
appropriate for WSHPs, DOE evaluated whether the components needed to 
calculate IEER can be linearly interpolated across EWT. Specifically, 
the parameters necessary for the calculation of IEER are EER, capacity, 
total power, and all components of power (i.e., compressor power, fan 
power, condenser section power, controls power). DOE tested 15 units at 
different EWTs to compare physical tested results and interpolated and 
extrapolated values. The method evaluated by DOE determines IEER 
ratings for WSHPs by interpolation and extrapolation from full-load 
tests at liquid inlet temperatures of 86 [deg]F, 77 [deg]F, and 59 
[deg]F and, for two-stage and variable-speed units, part-load tests at 
86 [deg]F, 68 [deg]F, and 59 [deg]F. DOE first evaluated the accuracy 
of interpolating to a different EWT for full-load tests. For each of 
the 15 units tested, DOE conducted full-load tests to measure EER at 86 
[deg]F, 77 [deg]F, and 59 [deg]F. DOE then used the results from the 86 
[deg]F and 59 [deg]F tests to linearly interpolate to performance at 77 
[deg]F, and compared these interpolated results to the results of 
testing at 77 [deg]F. Table 3 presents a summary of the percentage 
differences between the interpolated and measured values. Positive 
values in the average, minimum, and maximum columns of Table 3 indicate 
that the values interpolated to 77 [deg]F from results measured at 86 
[deg]F and 59 [deg]F were higher than the values measured at 77 [deg]F, 
and negative values indicate the opposite.

   Table 3--Percentage Differences of Interpolated Results From Measured Results for Capacity, Power, and EER
----------------------------------------------------------------------------------------------------------------
                                                                                                      Average
                    Parameter                         Average         Minimum         Maximum     absolute value
----------------------------------------------------------------------------------------------------------------
Cooling Capacity................................            -0.2            -1.4             2.2             0.9
Total Power.....................................            -0.4            -2.6             1.5             0.8
Interpolated EER................................             2.3             0.3             4.8             2.3
EER calculated from interpolated capacity and                0.2            -1.7             2.9             1.0
 power..........................................
----------------------------------------------------------------------------------------------------------------
Note: Positive values in the average, minimum, and maximum columns indicate that the values interpolated to 77
  [deg]F from results measured at 86 [deg]F and 59 [deg]F were higher than the values measured at 77 [deg]F.
  Negative values in the average, minimum, and maximum columns indicate that the values interpolated to 77
  [deg]F from results measured at 86 [deg]F and 59 [deg]F were lower than the values measured at 77 [deg]F.

    As shown in Table 3, the interpolated values for cooling capacity 
and total power differed from the corresponding tested values by an 
average of less than 1 percent. Therefore, DOE has determined that 
interpolating capacity and total power results in representative values 
of capacity and total power, respectively. However, the interpolated 
EER value at 77 [deg]F was higher than the tested EER value at 77 
[deg]F for all tested units, with an average difference of 2.3 percent 
(ranging from 0.3 percent to 4.8 percent higher). Because of the 
consistent bias in the results showing interpolated EER higher than 
tested

[[Page 53315]]

EER,\17\ DOE considered an alternate approach of calculating EER based 
on interpolated values of cooling capacity and total power rather than 
interpolating EER directly. The bottom row of Table 3 shows the results 
of calculating EER at 77 [deg]F using the interpolated values of 
cooling capacity and total power. As shown in in the bottom row of 
Table 3, calculating EER at 77 [deg]F using interpolated values of 
cooling capacity and total power resulted in EER values that were on 
average 0.2 percent higher than the tested EER value at 77 [deg]F 
(ranging from 1.7 percent lower to 2.9 percent higher). Because 
determining EER by interpolating cooling capacity and total power 
results in closer agreement to tested values than directly 
interpolating EER (and does not consistently bias results toward higher 
interpolated EER values), DOE used the former approach in the 
calculation of IEER values discussed in the following paragraphs.
---------------------------------------------------------------------------

    \17\ As presented in Table 3, the results from DOE's testing 
show that that linear interpolation across EWT results in close 
agreement for cooling capacity and total power. Because EER = 
Cooling Capacity/Total Power, if linear equations are used to 
represent the relationship between cooling capacity and EWT, as well 
as between total power and EWT, the resulting equation for EER has 
equations linearly dependent on EWT in the numerator and 
denominator. Such an equation simplifies to an inverse function 
(i.e., the variable (EWT) is in the denominator), which is concave 
up (i.e., the slope of the EER vs EWT curve increases with 
increasing EWT), such that between any two points on the curve, the 
curve is always below a line drawn between the two points. 
Therefore, calculating EER by linearly interpolating EER values 
across EWT consistently results in an interpolated EER value that is 
higher than the EER value measured by testing or determined by 
linearly interpolating cooling capacity and total power.
---------------------------------------------------------------------------

    For determining IEER for single-stage units, this interpolation and 
extrapolation approach would be used to determine EER at the EWTs for 
all 4 IEER points, and the EER results for the part-load points (i.e., 
test points designated as B, C, and D in AHRI 340/360-2022) would also 
be adjusted for cyclic degradation (see discussion in section III.F.2.b 
of this document).
    For two-stage and variable-speed WSHPs, DOE evaluated a method that 
tests at the minimum compressor speed at the EWTs specified in Table 1 
of ISO 13256-1:1998 for part-load tests (i.e., at 86 [deg]F, 68 [deg]F, 
and 59 [deg]F). As with the draft AHRI 600 method, the method evaluated 
by DOE then provides for interpolating to the IEER liquid inlet 
temperatures from these part-load tests, and IEER is determined using 
interpolated results for the IEER EWTs for both full-load and part-load 
tests.\18\ To evaluate the accuracy of this methodology for calculating 
IEER for staged WSHPs, DOE conducted additional investigative testing 
on 10 of the 15 tested WSHPs (6 two-stage WSHPs and 4 variable-speed 
WSHPs). Specifically, these 10 units were tested to calculate IEER via 
the interpolation and extrapolation method (by conducting full-load and 
part-load tests at the EWTs specified in Table 1 of ISO 13256-1:1998 
and using interpolation and extrapolation to calculate IEER) and were 
tested to determine IEER per section 6.2 of AHRI 340/360-2022 by 
testing at the IEER EWTs and target load levels specified in Table 9 of 
AHRI 340/360-2022. Consistent with the discussion in the previous 
paragraphs, when interpolating to determine performance at a different 
EWT for a given compressor stage for staged units, DOE calculated the 
EER values by interpolating and extrapolating values of cooling 
capacity and total power, rather than directly interpolating and 
extrapolating values of EER. Table 4 presents a summary of the results. 
Positive values in the average, minimum, and maximum columns of Table 4 
indicate that the IEER values determined via the interpolation and 
extrapolation method were higher than the IEER values determined 
through testing at the EWTs and load levels specified in section 6.2 of 
AHRI 340/360-2022, and negative values indicate the opposite.
---------------------------------------------------------------------------

    \18\ After interpolating the full-load and part-load 
interpolated across EWT, the AHRI 340/360-2022 IEER calculation 
methodology is then used. The interpolated results would either need 
cyclic degradation (see discussion in section III.F.2.b of this 
NOPR) or interpolation across compressor staging to determine the 
specific load EER values to be used in the IEER calculation, unless 
the EWT interpolation yields a calculated percent load that meets 
the 3 percent tolerance for the respective IEER load point.

 Table 4--Percentage Differences of Interpolated IEER From Measured IEER for Two-Stage and Variable-Speed Units
----------------------------------------------------------------------------------------------------------------
                                                                                                      Average
              Capacity control type                   Average         Minimum         Maximum     absolute value
----------------------------------------------------------------------------------------------------------------
Two-Stage.......................................            -0.9            -2.7            -0.0             0.9
Variable-Speed..................................            -6.3           -13.6             0.2             6.4
----------------------------------------------------------------------------------------------------------------
Note: Positive values in the average, minimum, and maximum columns indicate that the IEER values determined via
  the interpolation and extrapolation method were higher than the IEER values determined through testing at the
  EWTs and load levels specified in section 6.2 of AHRI 340/360-2022. Negative values in the average, minimum,
  and maximum columns indicate that the IEER values determined via the interpolation and extrapolation method
  were lower than the IEER values determined through testing at the EWTs and load levels specified in section
  6.2 of AHRI 340/360-2022.

    As shown in Table 4, for the six tested two-stage WSHPs, the IEER 
values calculated using the described interpolation and extrapolation 
method were on average 0.9 percent lower than the IEER value measured 
from testing per AHRI 340/360-2022 (ranging from 0.0 percent to 2.7 
percent lower).
    For the four variable-speed units, the IEER values calculated using 
the described interpolation and extrapolation method were on average 
6.3 percent lower than the IEER value measured from testing per AHRI 
340/360-2022 (ranging from 0.2 percent higher to 13.6 percent lower). 
These results demonstrate a wider discrepancy from AHRI 340/360-2022 
results than for single-stage or two-stage WSHPs. This discrepancy is 
likely because the interpolation and extrapolation method described 
only includes testing at maximum and minimum compressor speed, whereas 
the AHRI 340/360-2022 approach includes testing at compressor speeds to 
operate at each of the part-load test points (i.e., 75 percent, 50 
percent, and 25 percent load). Therefore, for variable-speed WSHPs with 
higher EER at intermediate compressor speeds than at maximum or minimum 
compressor speeds, the interpolation and extrapolation method described 
results in a lower calculated IEER than testing at the IEER conditions 
specified in AHRI 340/360-2022, which was the case for three of the 
four tested units. While for certain tested variable-speed units 
calculating IEER via interpolation and extrapolation resulted in a 
lower IEER value, from participation in AHRI 600 committee

[[Page 53316]]

meetings, DOE understands that many manufacturers would prefer the 
option to use the interpolation and extrapolation method for variable-
speed WSHPs even if it results in lower IEER ratings, because it would 
result in less overall testing burden than testing at each of the AHRI 
340/360-2022 conditions.
    Based on the investigative testing conducted, DOE has tentatively 
concluded that determining IEER via interpolation and extrapolation 
from testing at the ISO 13256-1:1998 EWTs (in accordance with DOE's 
proposed test procedure), similar to the method in the draft AHRI 600, 
provides appropriately representative results that are comparable to 
testing at the EWTs (and for staged units, load levels) specified in 
Table 9 of AHRI 340/360-2022. Therefore, DOE is proposing in section 5 
of the proposed appendix C1 to allow that IEER for WSHPs can be 
calculated from either of two methods: (1) ``option 1''--testing in 
accordance with AHRI 340/360-2022 (at EWTs of 85 [deg]F, 73.5 [deg]F, 
62 [deg]F, and 55 [deg]F); or (2) ``option 2''--interpolation and 
extrapolation of cooling capacity and power values based on testing in 
accordance with the proposed test procedure at EWTs of 86 [deg]F, 77 
[deg]F, and 59 [deg]F for full-load tests and (for staged units) EWTs 
of 86 [deg]F, 68 [deg]F, and 59 [deg]F for part-load tests. For single 
speed units, option 2 would require three full-load tests at entering 
liquid temperatures of 86 [deg]F, 77 [deg]F, and 59 [deg]F. For two-
stage and variable-speed units, three additional tests at the minimum 
compressor speed would be required, at entering liquid temperature of 
86 [deg]F, 68 [deg]F, and 59 [deg]F.
    Specifically for option 2, aside from the EWTs, the tests for 
option 2 would be performed using the same test provisions from AHRI 
340/360-2022, ANSI/ASHRAE 37-2009, and sections 2 through 4 and 7 of 
proposed appendix C1 as the tests for option 1. As discussed, DOE has 
tentatively determined that results from the interpolation and 
extrapolation method have greater agreement with, and, therefore, are 
comparably representative to, the tested results by interpolating 
values of cooling capacity and total power rather than interpolating 
values of EER; therefore, DOE is proposing that the alternative method 
specify interpolation using the cooling capacity and total power. The 
proposed provisions for option 2 in section 5.1.2 of proposed appendix 
C1 are otherwise generally consistent with the draft AHRI 600 method, 
except for the cyclic degradation approach, which is discussed in 
section III.F.2.b of this NOPR.
    DOE notes that representations for WSHPs can be made either based 
on testing (in accordance with 10 CFR 429.43(a)(1)) or AEDMs (in 
accordance with 10 CFR 429.43(a)(2)). If represented values for a basic 
model are determined with an AEDM, the AEDM could use either option 1 
or option 2 for determining IEER per the proposed test procedure in 
appendix C1.
    Issue 4: DOE requests comment on the proposal to allow 
determination of IEER using two different methods: (1) testing in 
accordance with AHRI 340/360-2022; or (2) interpolation and 
extrapolation of cooling capacity and power values based on testing in 
accordance with the proposed test procedure at the EWTs specified in 
Table 1 of ISO 13256-1:1998. Specifically, DOE seeks feedback on the 
proposed method for calculating IEER via interpolation and 
extrapolation, and on whether this approach would serve as a potential 
burden-reducing option as compared to testing at the AHRI 340/360-2022 
conditions.
    Issue 5: DOE requests comment on whether the proposed methodology 
to determine IEER based on interpolation and extrapolation is 
appropriate for variable-speed units. DOE would consider requiring 
variable-speed equipment be tested only according to AHRI 340/360-2022 
and, thus, testing physically at the IEER EWTs, if suggested by 
commenters.
    DOE is aware that ISO 13256-1:2021 includes changes from ISO 13256-
1:1998 with respect to the EWTs specified for cooling tests. 
Specifically, Table 2 of ISO 13256-1:2021 specifies full-load cooling 
temperatures of 86 [deg]F, 68 [deg]F, and 50 [deg]F, and part-load 
cooling temperatures of 77 [deg]F, 59 [deg]F, and 41 [deg]F. Consistent 
with the draft AHRI 600 method, DOE is proposing to use the 
temperatures specified in Table 1 of ISO 13256-1:1998 for option 2 
tests; however, it is expected that the results under the proposed 
interpolation and extrapolation method would provide comparable results 
using the EWTs specified in Table 2 of ISO 13256-1:2021.
    Issue 6: DOE seeks feedback on whether the proposed interpolation 
and extrapolation method should be based on testing at the ISO 13256-
1:2021 EWTs.
2. COP
a. General Discussion
    DOE's current test procedure for WSHPs measures heating-mode 
performance in terms of the COP metric, based on testing with a 68 
[deg]F EWT. 10 CFR 431.96. For the reasons explained in the following 
paragraphs, DOE is proposing in section 6.2 of proposed appendix C1 to 
use an EWT of 55 [deg]F for the COP metric because DOE has tentatively 
concluded that 55 [deg]F is more representative of field operation than 
the current EWT of 68 [deg]F.
    COP is a full-load heating efficiency metric for WSHP water-loop 
applications, meaning that it represents the heating efficiency for a 
WSHP operating at its maximum capacity at an EWT that is typical of 
heating operation in water-loop applications. Because commercial 
buildings served by WSHPs in water-loop applications are typically 
cooling-dominated, DOE understands that the majority of heating hours 
in these applications occur in simultaneous cooling and heating 
operation--in which certain WSHPs (e.g., servicing zones around the 
perimeter of the building) are in heating mode while other WSHPs (e.g., 
servicing interior zones closer to the center of the building) are in 
cooling mode. Because all WSHPs in the system loop are provided water 
with the same EWT, at any given time, WSHPs that are in heating mode 
operate at the same EWT as WSHPs in cooling mode. As discussed in 
section III.E.1.a of this NOPR, from manufacturer feedback provided in 
AHRI 600 committee meetings, DOE understands that while in the past 
water-loop temperatures were maintained at temperatures above 60 [deg]F 
via heat provided by a system boiler, in current practice, WSHP 
installations are typically controlled to allow water-loop temperatures 
to drop to temperatures closer to 50 [deg]F. Correspondingly, DOE is 
proposing part-load IEER EWTs that align with AHRI 340/360-2022 and the 
draft AHRI 600, including 62 [deg]F for the 50-percent load point and 
55 [deg]F for the 25-percent load point.
    Because DOE understands that WSHP water-loop temperatures are 
typically controlled to drop closer to 50 [deg]F (as represented by the 
55 [deg]F EWT for the 25-percent load point), the Department 
understands that most hours of heating mode operation for WSHPs in 
water-loop applications occur with EWTs closer to 50 [deg]F. Therefore, 
while the current 68 [deg]F EWT for the COP metric may have been more 
representative of how WSHP systems were controlled in the past (i.e., 
with a boiler maintaining water-loop temperatures above 60 [deg]F), DOE 
has tentatively determined that the COP EWT should be no higher than 
the lowest EWT used in the IEER metric, which is 55 [deg]F (for the 25-
percent load point), because most heating hours occur when outdoor air 
temperatures are lower and, thus, cooling loads are

[[Page 53317]]

lower. Therefore, DOE has tentatively concluded that the COP metric 
would be more representative of water-loop WSHP applications if based 
on an EWT of 55 [deg]F.
    DOE also considered whether an EWT below 55 [deg]F, specifically 50 
[deg]F, might be more representative for determining COP, depending 
upon typical heating conditions for water-loop WSHPs. However, DOE 
currently lacks data or evidence indicating that 50 [deg]F would be a 
more representative heating EWT than 55 [deg]F for WSHPs. Therefore, in 
the absence of any data suggesting a lower EWT would be more 
representative of heating operation of WSHPs, DOE is proposing an EWT 
of 55 [deg]F, which aligns with the lowest IEER EWT as proposed.
    Issue 7: DOE seeks comment and data on the representativeness of 55 
[deg]F as the EWT condition for determining COP. Specifically, DOE 
requests feedback and data on whether a lower EWT, such as 50 [deg]F, 
would be more representative of heating operation of WSHPs. DOE will 
further consider any alternate EWT suggested by comments in developing 
any final rule.
    Additionally, DOE is proposing provisions in section 6.3 of 
proposed appendix C1 to provide for optional representations of COP 
based on testing conducted per the proposed test procedure (sections 2 
through 4 and 7 of proposed appendix C1) at the full-load and part-load 
EWT conditions specified in Table 2 of ISO 13256-1:1998 (i.e., 68 
[deg]F, 50 [deg]F, 41 [deg]F, and 32 [deg]F).
b. Determination of COP Via Interpolation
    As discussed in section III.E.1.b of this NOPR, DOE is proposing to 
include an alternate method for determining IEER that allows 
manufacturers to perform tests at the EWTs in Table 1 of ISO 13256-
1:1998 and interpolate efficiency metrics to the EWTs specified in 
Table 9 of AHRI 340/360-2022. This method would reduce overall testing 
burden for manufacturers who choose to make optional EER 
representations at the EWTs specified in Table 1 of ISO 13256-1:1998, 
by allowing them to avoid additional testing at the IEER EWTs.
    In order to provide comparable flexibility for measuring COP, DOE 
is proposing a similar alternative test method in section 6.2.2 of 
appendix C1 for determining COP by interpolation from results of 
testing at the EWTs specified in Table 2 of ISO 13256-1:1998. To 
evaluate the interpolation method for COP, DOE conducted investigative 
testing on five WSHPs at the three heating EWTs specified in Table 1 of 
ISO 13256-1:1998: 68 [deg]F, 50 [deg]F and 32 [deg]F. DOE interpolated 
the cooling capacity and total power results from 68 [deg]F and 32 
[deg]F to 50 [deg]F, and then calculated COP at 50 [deg]F using the 
interpolated values of cooling capacity and total power.\19\ Finally, 
DOE compared these interpolated values to the results of testing at 50 
[deg]F. Table 5 presents a summary of the percentage differences 
between the interpolated and measured values. Positive values in the 
average, minimum, and maximum columns of Table 5 indicate that the 
values interpolated to 50 [deg]F from results measured at 68 [deg]F and 
32 [deg]F were higher than the values measured at 50 [deg]F, and 
negative values indicate the opposite.
---------------------------------------------------------------------------

    \19\ As discussed in section III.E.1.b of this NOPR, DOE 
tentatively determined that interpolation of EER directly results in 
a consistent bias, and that more representative results are obtained 
by calculating EER using interpolated values of cooling capacity and 
total power. Similarly, for COP, DOE is proposing that COP can be 
determined using interpolated values of heating capacity and total 
power, rather than interpolating COP values directly.

   Table 5--Percentage Differences of Interpolated Results From Measured Results for Capacity, Power, and COP
----------------------------------------------------------------------------------------------------------------
                                                                                                      Average
                    Parameter                         Average         Minimum         Maximum     absolute value
----------------------------------------------------------------------------------------------------------------
Cooling Capacity................................            -0.4            -1.9             0.6             0.9
Total Power.....................................             0.3            -1.2             2.1             0.9
COP calculated from interpolated capacity and               -0.7            -3.9             0.9             1.1
 power..........................................
----------------------------------------------------------------------------------------------------------------
Note: Positive values in the average, minimum, and maximum columns indicate that the values interpolated to 50
  [deg]F from results measured at 68 [deg]F and 32 [deg]F were higher than the values measured at 50 [deg]F.
  Negative values in the average, minimum, and maximum columns indicate that the values interpolated to 50
  [deg]F from results measured at 68 [deg]F and 32 [deg]F were lower than the values measured at 50 [deg]F.

    As shown in Table 4, the COP calculated from interpolated values of 
cooling capacity and total power differed from measured COP by an 
average of less than 1 percent. Therefore, DOE has tentatively 
concluded that determining COP via interpolation in this temperature 
range from testing at the ISO 13256-1:1998 EWTs (in accordance with 
DOE's proposed test procedure) provides appropriately representative 
results that are comparable to testing at 55 [deg]F. Therefore, DOE is 
proposing in section 6.2 of the proposed appendix C1 to allow that COP 
for WSHPs can be calculated from either of two methods: (1) ``option 
A''--testing at 55 [deg]F; or (2) ``option B''--interpolation of 
heating capacity and power values based on testing in accordance with 
the proposed test procedure at EWTs of 50 [deg]F and 68 [deg]F. Aside 
from the EWTs, the tests for option B would be performed using the same 
test provisions from AHRI 340/360-2022, ANSI/ASHRAE 37-2009, and 
sections 2 through 4 and 7 of proposed appendix C1 as the tests for 
option A.
    Issue 8: DOE requests comment on the proposal to allow 
determination of COP using two different methods: (1) testing at 55 
[deg]F; or (2) interpolation of heating capacity and power values based 
on testing in accordance with the proposed test procedure at EWTs 
specified for heating tests in Table 2 of ISO 13256-1:1998 (i.e., 50 
[deg]F and 68 [deg]F). Specifically, DOE seeks feedback on the proposed 
method for calculating COP via interpolation, and on whether this 
approach would serve as a potential burden-reducing option as compared 
to testing at 55 [deg]F.
3. Entering Air Conditions
    The current DOE test procedure references ISO 13256-1:1998, which 
specifies in Table 1 that EER is measured with entering air at 27 
[deg]C (80.6 [deg]F) dry-bulb temperature and 19 [deg]C (66.2 [deg]F) 
wet-bulb temperature and in Table 2 that COP is measured with entering 
air at 20 [deg]C (68 [deg]F) dry-bulb temperature and 15 [deg]C (59 
[deg]F) wet-bulb temperature. Table 2 and Table 3 of ISO 13256-1:2021 
specify the same entering air conditions as ISO 13256-1:1998. As

[[Page 53318]]

discussed in section III.D.3 of this NOPR, DOE proposes to adopt AHRI 
340/360-2022 as the test procedure for WSHPs. Table 6 of AHRI 340/360-
2022 specifies entering indoor air conditions for standard rating 
cooling tests to be 80 [deg]F dry-bulb temperature and a maximum of 67 
[deg]F wet-bulb temperature and standard rating heating tests to be 70 
[deg]F dry-bulb temperature and a maximum of 60 [deg]F wet-bulb 
temperature.
    The entering air conditions specified in AHRI 340/360-2022 are 
similar to the conditions specified in ISO 13256-1:1998 and ISO 13256-
1:2021, differing for cooling by 0.6 [deg]F for dry-bulb temperature 
and 0.8 [deg]F for wet-bulb temperature and for heating by 2 [deg]F for 
dry-bulb temperature and 1 [deg]F for wet-bulb temperature. DOE 
surmises that these differences are likely due to the conditions in ISO 
13256-1 (1998 and 2021 versions) being specified in terms of degrees 
Celsius, whereas the conditions in AHRI 340/360-2022 are specified in 
degrees Fahrenheit. The entering air conditions specified in AHRI 340/
360-2022 are the same as in previous versions of AHRI 340/360, 
including AHRI 340/360-2007, which is referenced in the current DOE 
test procedure for CUAC/HPs. Further, the most common application for 
WSHPs (and the application DOE understands that the WSHP industry is 
intending to represent via use of the IEER metric in AHRI 600) is 
commercial buildings, similar to CUAC/HPs. Therefore, DOE has 
tentatively determined that the entering air conditions in AHRI 340/
360-2022 are appropriately representative of the average conditions in 
which WSHPs operate in the field. DOE is proposing in sections 5 and 6 
of proposed appendix C1 to use entering air conditions from Table 6 of 
AHRI 340/360-2022 for both cooling (IEER) and heating (COP) tests.
    Issue 9: DOE requests comment on its proposal to specify in 
proposed appendix C1 use of the cooling entering air conditions from 
AHRI 340/360-2022 (i.e., 80 [deg]F dry-bulb temperature and 67 [deg]F 
wet-bulb temperature) and the heating entering air conditions from AHRI 
340/360-2022 (i.e., 70 [deg]F dry-bulb temperature and a maximum of 60 
[deg]F wet-bulb temperature).
4. Operating Modes Other Than Mechanical Cooling and Heating
    On April 1, 2015, DOE published in the Federal Register a 
notification of its intent to establish a working group under the 
Appliance Standards and Rulemaking Federal Advisory Committee 
(``ASRAC'') Commercial and Industrial Fans and Blowers Working Group 
(``ASRAC Working Group'') to discuss and, if possible, reach consensus 
on the scope of the rulemaking, certain key aspects of a proposed test 
procedure, and proposed energy conservation standard for fans and 
blowers. 80 FR 17359. The ASRAC Working Group term sheet for commercial 
and industrial fans and blowers was approved (Docket No. EERE-2013-BT-
STD-0006-0179).\20\ Recommendation #3 of the term sheet addressed 
supply and condenser fans that are embedded in certain covered 
equipment. (Id. at p. 3) The ASRAC Working Group recommended that DOE 
consider revising efficiency metrics that include energy use of supply 
fans in order to include the energy consumption during all relevant 
operating modes (e.g., auxiliary heating mode, ventilation mode, and 
part-load operation) in the next round of test procedure rulemakings. 
(Id. at p. 4) The ASRAC Working Group included WSHPs in its list of 
regulated equipment for which fan energy use should be considered. (Id. 
at p. 16)
---------------------------------------------------------------------------

    \20\ Available at: www.regulations.gov/document/EERE-2013-BT-STD-0006-0179.
---------------------------------------------------------------------------

    As part of the June 2018 RFI, DOE stated that it was investigating 
whether changes to the WSHP test procedure are needed to properly 
characterize a representative average use cycle, including changes to 
more accurately represent fan energy use in field applications. 83 FR 
29048, 29050 (June 22, 2018). DOE requested information as to the 
extent that accounting for the energy use of fans in commercial 
equipment such as WSHPs would be additive of other existing accountings 
of fan energy use. Id.
    In the June 2018 RFI, DOE also sought comment on whether accounting 
for the energy use of fan operation in WSHPs would alter measured 
efficiency, and if so, to what extent. Id. DOE also requested data and 
information regarding what forms of auxiliary heating are installed in 
WSHPs, how frequently they operate, and whether they operate 
independently of the WSHP. Id. Additionally, DOE requested data and 
information on how frequently WSHP supply fans are operated when there 
is no demand for heating or cooling, such as for fresh air ventilation 
or air circulation or filtration. Id.
    The Joint Advocates and NEEA commented that DOE should amend the 
test procedure to account for fan energy use outside of mechanical 
cooling and heating for fans in regulated equipment to more fully 
capture fan energy use. (Joint Advocates, No. 10 at p. 1; NEEA, No. 11 
at p. 1) The Joint Advocates asserted that by failing to capture fan 
operation for economizing, ventilation, and other functions outside of 
cooling mode, the test procedure may be significantly underestimating 
fan energy consumption. (Joint Advocates, No. 10 at p. 1)
    NEEA commented that the commercial prototype building models used 
by Pacific Northwest National Laboratory in the analysis in support of 
ASHRAE Standard 90.1 include information on the operation of fans in 
ventilation mode and economizer mode and could be used to develop 
national average fan operating hours outside of heating and cooling. 
(NEEA, No. 11 at pp. 3) Furthermore, NEEA stated that the vast majority 
of WSHPs are installed in commercial buildings, thereby subjecting them 
to ASHRAE Standard 90.1 code requirements such as the requirement of 
water side economizers in many U.S. climate zones. Id. NEEA added that 
details of requirements for certain control and component features are 
provided in ASHRAE Standard 90.1 and should be an indicator of 
prevalence of these features in WSHPs on the market. Id.
    NEEA further stated that ANSI and the Air Movement Control 
Association (``AMCA'') developed ANSI/AMCA 208-18, ``Calculation of the 
Fan Energy Index,'' which provides a potential way to measure embedded 
fan performance in WSHPs using the fan energy index (``FEI''). 
According to NEEA, DOE could develop a revised IEER-type metric that 
weighs together cooling performance (using the IEER test) and fan 
efficiency (using an FEI-based metric). NEEA argued that accounting for 
the energy use of fan operation in WSHPs does not need to alter 
measured efficiency, and that to reduce burden on manufacturers, DOE 
could combine the FEI and IEER metrics such that manufacturers would 
have multiple viable design option pathways to achieve the minimum IEER 
efficiency standard without improving the embedded fan efficiency above 
the minimum FEI efficiency standard. (NEEA, No. 11 at p. 2)
    Trane commented that there are some applications in which a WSHP 
would be used for ventilation, but that ventilation is not the main 
use, and that using a WSHP for purposes other than heating and cooling 
is rare. Trane stated further that typical practice is for ventilation 
air to be provided by a dedicated outdoor air system (``DOAS'') using a 
separate ductwork system, whereas the WSHP system provides the heating 
and cooling. Finally, Trane commented that for installations in which 
the DOAS and WSHPs supply to common ductwork, WSHP fans would operate 
when

[[Page 53319]]

ventilation is needed, but rarely would this be needed without heating 
or cooling. (Trane, No. 8 at pp. 2, 5)
    AHRI and WaterFurnace both stated that a high percentage of WSHP 
systems offer a continuous fan mode to circulate fresh air but did not 
have data on how often. (AHRI, No. 12 at pp. 4-5; WaterFurnace, No. 7 
at p. 3) However, both estimated that a typical WSHP would operate in 
continuous fan mode (i.e., without cooling or heating) for 
approximately 1,300 hours per year. The commenters estimated total 
cooling and heating mode operation of 3,300 hours per year. (AHRI, No. 
12 at pp. 9; WaterFurnace, No. 7 at p. 9)
    Further, AHRI and WaterFurnace commented that fan power is largely 
dependent on motor type and typically represents 13 to 18 percent of 
total power. (AHRI, No. 12 at pp. 4, 8-9; WaterFurnace, No. 7 at pp. 3, 
8-9) AHRI asserted that EPCA imposes a one-metric-per-product 
limitation and that efforts to capture the energy use of a fan during a 
mode other than cooling (or heating) would result in an impermissible 
design requirement. (AHRI, No. 12 at pp. 5, 10)
    AHRI stated that DOE has the authority to include certain fans and 
blowers, by rule, as ``covered equipment'' if such products meet all 
the requirements of EPCA at 42 U.S.C. 6311(2). AHRI asserted that if 
DOE developed a standard for stand-alone industrial fans, it would not 
be appropriate to apply that standard to fans embedded in regulated 
equipment. Furthermore, AHRI argued that the fact that Congress granted 
a specific provision of authority to DOE for a consumer furnace 
ventilation metric affirms that DOE is without general authority to 
create overlapping ventilation requirements for other regulated 
products. (AHRI, No. 12 at pp. 10-11)
    Trane and WaterFurnace also commented that regulation of WSHP fans 
would produce unnecessary overlapping regulations, and that system-
level efficiency metrics allow for optimization of the entire system. 
(Trane, No. 8 at p. 4; WaterFurnace, No. 7 at p. 8) AHRI and 
WaterFurnace stated that fan energy in cooling and heating are 
accounted for in the current test procedure and that fans are optimized 
for these modes because they account for the majority of operational 
time. (AHRI, No. 12 at p. 8; WaterFurnace, No. 7 at p. 9)
    AHRI and WaterFurnace commented that auxiliary heating is not 
common in WSHPs and estimated that electric heat is included in less 
than one percent of WSHP shipments. AHRI and WaterFurnace further 
commented that the primary mode of operation of most WSHPs is cooling 
and that heating requirements are limited, such that adequate heating 
can be supplied through heat pump operation alone. (AHRI, No. 12 at p. 
4; WaterFurnace, No. 7 at p. 3) Trane stated that for their WSHPs, 
electric heat is provided only when heat pump operation alone cannot 
meet the heating demand. Trane further stated that the compressors are 
locked out while back-up electric heating is used for most WSHPs, with 
the exception of rooftop WSHP equipment, which allows auxiliary 
electric heat to supplement the heating provided by the heat pump. 
(Trane, No. 8 at p. 2)
    In response, DOE emphasizes that its request for information 
regarding fan energy use was in investigation of energy use of WSHPs in 
operational modes other than those currently evaluated by the test 
procedure (i.e., operational modes other than cooling and heating). DOE 
understands that much of the energy use attributable to these other 
modes is likely a product of fan operation. Provisions to measure 
energy use for ancillary functions (e.g., economizing, ventilation, 
filtration, and auxiliary heat) when there is no heating or cooling are 
not included in ISO 13256-1:1998 or AHRI 340/360-2022. As discussed in 
section III.D.3 of this NOPR, DOE is proposing to adopt AHRI 340/360-
2022 for testing WSHPs. Additionally, provisions addressing other 
operational modes have not been included in the updated ISO 13256-
1:2021. In light of the above, at this time, DOE lacks sufficient 
information on the number of units capable of operating in these other 
modes or the frequency of operation of these modes during field 
conditions to determine whether such testing would be appropriate for 
WSHPs and/or to develop a test method capable of accounting for energy 
use of such auxiliary functions of WSHPs. To the extent that data and 
further information are developed regarding operation of WSHPs in modes 
other than mechanical cooling and heating, DOE would consider such 
developments in a future WSHP test procedure rulemaking.
5. Dynamic Load-Based Test Procedure
    In response to the June 2018 RFI, both NEEA and the Joint Advocates 
encouraged DOE to investigate a load-based test method that could allow 
more sophisticated and inclusive efficiency metrics. Both NEEA and 
Joint Advocates commented that the Canadian Standards Association 
(``CSA'') group is developing CSA EXP07 (``Load-based and climate-
specific testing and rating procedures for heat pumps and air 
conditioners''), which is a dynamic, load-based test procedure expected 
to better capture performance in the field, including the capturing of 
cycling losses, benefits of variable-speed operation, and importance of 
control strategies. (NEEA, No. 11 at p. 2; Joint Advocates, No. 10 at 
p. 2)
    DOE is aware of the dynamic, load-based test procedure being 
developed by CSA. However, at this time, DOE understands that CSA EXP07 
has not been validated and finalized. Furthermore, the CSA EXP07 test 
procedure is applicable to CAC/HPs, and that test procedure has not yet 
been evaluated for WSHPs. Further, DOE is not aware of data showing 
that any dynamic, load-based test procedure produces repeatable and 
reproducible test results. Therefore, DOE has tentatively concluded 
that further consideration of CSA EXP07 would be premature at this 
time, and accordingly, the Department is not proposing to adopt any 
dynamic, load-based test procedures in this NOPR.

F. Test Method

1. Airflow and External Static Pressure
a. Fan Power Adjustment and Required Air External Static Pressure
    As discussed in section III.D.1.a of this NOPR, for ducted units, 
sections 4.1.3.1 and 4.1.3.2 of ISO 13256-1:1998 specify a fan power 
adjustment calculation that does not account for fan power used for 
overcoming external resistance. As a result, the calculation of 
efficiency includes only the fan power required to overcome the 
internal resistance of the unit. In addition, ISO 13256-1:1998 does not 
specify ESP requirements for ducted equipment, instead allowing 
manufacturers to specify a rated ESP. While Table 9 of ISO 13256-1:1998 
includes an operating tolerance (i.e., maximum variation of individual 
reading from rating conditions) and a condition tolerance (i.e., 
maximum variation of arithmetical average values from specified test 
conditions) for external resistance to airflow, the test standard does 
not specify to which values of ESP these tolerances are intended to 
apply.
    In the June 2018 RFI, DOE requested comment on whether minimum ESP 
requirements should be included for ducted WSHPs, and if so, what 
values would be appropriate. 83 FR 29048, 29050 (June 22, 2018). DOE 
also requested information on whether field ESP values typically vary 
with capacity, and whether fan power used for overcoming ESP should be 
included in the efficiency calculation for WSHPs

[[Page 53320]]

intended to be used with ducting. Id. DOE asked for comment and data on 
whether the fan/motor efficiency factor used in the calculation of fan 
power for WSHPs is representative of units currently on the market and 
whether the value accurately represents the efficiency of existing fans 
that are not replaced in WSHP installations. Id at 83 FR 29051. 
Additionally, DOE requested comment on whether indoor fans are 
typically replaced when coil-only WSHPs are installed. Id.
    In response to DOE's request for information, the Joint Advocates 
encouraged DOE to establish minimum ESP values for ducted equipment and 
to include the fan power used for overcoming external resistance in 
efficiency calculations for WSHPs. (Joint Advocates, No. 10 at pp. 1-2) 
NEEA commented that representative ESPs for WSHPs are higher than zero 
ESP, and the commenter recommended that DOE should ensure the WSHP ESP 
requirements reflect field installations, stating that otherwise, WSHP 
ratings will neither provide an adequate representation of actual 
efficiency nor provide good information to consumers. (NEEA, No. 11 at 
p. 3) NEEA also reminded that the ASRAC Working Group recommended that 
test procedures for regulated equipment, including WSHPs, be revised to 
better capture fan energy use. NEEA further commented that adding 
minimum ESP values would not increase test burden. Id.
    AHRI, Trane, and WaterFurnace stated that the AHRI WSHP 
certification program does require minimum ESPs that increase with 
rated capacity for ducted units with fans driven by an electronically-
commutated motor (``ECM''), and that these minimum ESPs are being 
considered for inclusion in the revised version of ISO 13256-1. (AHRI, 
No. 12 at pp. 5-6; Trane, No. 8 at p. 3; WaterFurnace, No. 7 at p. 5) 
AHRI and WaterFurnace commented that the field ESP of commercial WSHPs 
is largely tied to the ductwork and a single filter, typically 
resulting in ESPs less than 0.50 inches water column (``in 
H2O''), but the commenters noted that some larger systems 
(>60,000 Btu/h) may be installed such that ESP values are as much as 
1.0 in H2O. (AHRI, No. 12 at p. 5; WaterFurnace, No. 7 at p. 
4) AHRI also mentioned that commercial WSHPs are not typically 
installed with substantial ancillary filters or other high-static 
accessories found in larger air handlers. (AHRI, No. 12 at p. 5)
    Trane and AHRI commented that fan power for overcoming ESP should 
not be included in the efficiency calculation. (AHRI, No. 12 at p. 6; 
Trane, No. 8 at pp. 2-3) AHRI further commented that the ISO 13256-
1:1998 approach (of including a fan power adjustment down to zero ESP) 
results from the acknowledgment of the variability of ESP in the wide 
variety of WSHP applications that range from cooling towers/boilers to 
dry coolers to geothermal earth loop systems. (AHRI, No. 12 at p. 5) 
Trane and WaterFurnace further commented that excluding the fan power 
for overcoming ESP from the efficiency calculation ensures that units 
with indoor fans that produce higher static pressure are not penalized 
for having a stronger fan motor. (Trane, No. 8 at pp. 2-3; 
WaterFurnace, No. 7 at p. 4) WaterFurnace added that because more 
powerful fans to overcome higher field ESPs results in lower certified 
efficiency, most manufacturers design to the minimum ESP to avoid the 
excess fan power, and that in field applications, this results in low 
airflow and poor performance. WaterFurnace commented that their typical 
WSHP product is tested at higher ESP (greater than 0.4 in 
H2O) but then corrected to zero ESP. (WaterFurnace, No. 7 at 
pp. 1, 4) AHRI stated that fewer than 10 percent of all installed WSHPs 
have a cooling capacity greater than 5 tons, and the organization 
further noted that the table of ESP requirements in AHRI WSHP/
Geothermal Operations Manual specifies an ESP of 0.20 in H2O 
for 5-ton models, suggesting that 90 percent of WSHPs would have an ESP 
less than 0.2 in H2O. (AHRI, No. 12 at p. 8)
    AHRI and WaterFurnace commented that the AHRI WSHP/Geothermal 
Operations Manual limits the fan power correction to three percent on 
the cooling capacity to prevent any application of the correction as a 
way to inflate efficiencies. (AHRI, No. 12 at p. 8; WaterFurnace, No. 7 
at p. 8) AHRI and WaterFurnace further commented that aligning ESP 
requirements for different equipment categories (with different 
conditions and applications) is futile and that there will always be 
differences in HVAC test standards. (AHRI, No. 12 at p. 8; 
WaterFurnace, No. 7 at p. 7) AHRI, Trane, and WaterFurnace stated that 
the fan power adjustment factor in ISO 13256-1:1998 is representative 
for WSHPs. (AHRI, No. 12 at p. 8; Trane, No. 8 at p. 4; WaterFurnace, 
No. 7 at p. 8) AHRI, Trane, and WaterFurnace also stated that the fan 
power adjustment factor provides the ability to predict performance at 
any ESP level. (AHRI, No. 12 at p. 3; Trane, No. 8 at p. 3; 
WaterFurnace, No. 7 at p. 5)
    AHRI and WaterFurnace also stated that the fan efficiency factor 
noted in the RFI is the same for all current fan motor designs, both 
permanent magnet variable speed and induction technologies, and they 
have found them to be reasonable. (AHRI, No. 12 at p. 8; WaterFurnace, 
No. 7 at p. 7) WaterFurnace further stated that the fan and pump 
correction factors were developed in 1998 after high-efficiency 
permanent split capacitor (``PSC'') and ECM fan motor technology were 
both deployed into the market and that the factor is intended to cover 
a number of technologies. (WaterFurnace, No. 7 at p. 7)
    Regarding whether indoor fans are typically replaced when coil-only 
WSHPs are installed, AHRI and WaterFurnace commented that they are not 
aware of any coil-only WSHPs, and, therefore, that test procedure 
revisions to address such units are unnecessary. (AHRI, No. 12 at p. 8; 
WaterFurnace, No. 7 at p. 8) AHRI and WaterFurnace also stated that all 
commercial WSHPs are packaged units and that split systems are not 
commercially used. Id.
    In response to those comments on the June 2018 RFI, DOE would 
clarify that ducted WSHPs installed in the field must overcome ESP from 
ductwork. As noted, the method used in ISO 13256-1:1998 and ISO 13256-
1:2021 excludes the power to overcome ESP via the fan power adjustment, 
which adjusts the fan power down to reflect zero ESP. In contrast, 
testing per AHRI 340/360-2022 requires testing at a minimum ESP 
requirement (specified in Table 7 of AHRI 340/360-2022) and does not 
include any adjustments to the fan power. In other words, ratings in 
accordance with AHRI 340/360-2022 reflect performance at the applicable 
minimum ESP requirement. DOE has tentatively concluded that testing 
ducted WSHPs in accordance with AHRI 340/360-2022 (i.e., testing at 
minimum ESP requirements with no fan power adjustment) would be more 
representative of field installations than the method used in ISO 
13256-1:1998, for the following three reasons:
    (1) Use of the fan power adjustment in ISO 13256-1:1998 results in 
ratings that do not reflect the fan power needed to overcome ESP;
    (2) The fan power adjustment in ISO 13256-1:1998 assumes a fan 
efficiency of 0.3, which underestimates the efficiency of fans in 
WSHPs, and, thus, underestimates the fan power that would be needed for 
the fan to operate at zero ESP; and
    (3) Rated ESP values that manufacturers use when testing to ISO 
13256-1:1998 are typically significantly higher than ESPs 
representative of water-loop WSHP installations. Because, as stated, 
the fan power

[[Page 53321]]

adjustment subtracts fan power to reflect performance at zero ESP, 
assuming a low fan efficiency, testing at ESPs higher than 
representative values subtracts more fan power than would typically be 
needed to overcome that high tested ESP, and, thus, it further results 
in efficiency ratings that underestimate fan power needed to operate at 
zero ESP.
    DOE conducted investigative testing on five WSHPs to determine the 
extent to which ISO 13256-1:1998 accounts for fan energy use compared 
to testing at representative ESP requirements per AHRI 340/360-2022. 
DOE also determined the fan efficiency of these five units. Of the five 
tested units, three had constant airflow ECM motors and two had 
constant torque ECM motors.

   Table 6--Investigative Testing Results Regarding Fan Power and Fan
                               Efficiency
------------------------------------------------------------------------
 
------------------------------------------------------------------------
Fan Power at AHRI 340/360 ESP Requirement (W)...........          262.04
Fan Power Determined According to ISO 13256-1:1998 (W)..          139.57
Average Measured Fan Efficiency.........................            0.46
Measured Fan Efficiency Range...........................       0.34-0.71
------------------------------------------------------------------------

    DOE determined the relationship between ESP and fan power for the 
five WSHPs by conducting several tests with varying ESP at the rated 
airflow. As shown in Table 5, DOE determined the fan power for each of 
the five units at the applicable ESP requirement in AHRI 340/360-2022. 
These data show that the method in ISO 13256-1:1998 accounts for an 
average of only 53 percent of the fan power required to overcome the 
ESP specified in AHRI 340/360-2022.
    DOE also calculated the fan efficiency for each unit based on tests 
conducted with varying ESP at the rated airflow. As shown in Table 5, 
DOE found that the measured fan efficiency for all five units is higher 
than the fan efficiency value assumed in ISO 13256-1:1998 (30 percent). 
Specifically, the average measured efficiency (46 percent) is over 50 
percent higher than the ISO 13256-1:1998 value, and the highest 
measured efficiency is more than double the ISO 13256-1:1998 value. The 
consistent underestimation of fan efficiency by the ISO 13256-1:1998 
fan power adjustment equation for the five tested units results in a 
larger amount of fan power being subtracted from the measured value 
when adjusting down to zero ESP than would be representative of the 
actual fan's operation. In other words, when adjusting the measured fan 
power down to zero ESP, the fan power adjustment's assumption of a fan 
efficiency that is lower than is typical in WSHPs results in more power 
being subtracted than the fan would actually have needed to overcome 
that level of ESP (because lower-efficiency fans consume more power to 
provide the same level of output). Therefore, for these five units the 
resulting rating determined per ISO 13256-1:1998 underestimates the fan 
power needed to operate at zero ESP because too much fan power is 
subtracted using the fan power adjustment.
    The low fan efficiency value in the ISO 13256-1:1998 fan power 
adjustment equation results in an incentive for manufacturers to test 
at a higher ESP than would be representative for WSHPs, to take more 
advantage of the fan power adjustment by subtracting a larger 
calculated adjustment from the measured fan power (when adjusting fan 
power down to reflect performance at zero ESP). DOE's examination of 
rated ESP values in supplemental test instructions (``STI'') indicates 
that WSHPs are being rated based on testing with ESPs higher than would 
be representative. Specifically, DOE examined the STI for 15 WSHPs and 
found that the average rated ESP was 0.51 in H2O. In 
contrast, the rated ESPs in the STI exceeded the AHRI 340/360-2022 ESP 
requirements (which, as discussed, align with the ESP levels included 
in the AHRI WSHP/Geothermal Operations Manual and are very similar to 
the ESP levels in included in ISO 13256:1-2021) by more than the +0.05 
in H2O tolerance for 13 of the 15 units. Given the low fan 
efficiency assumed in the ISO 13256-1:1998 fan power adjustment, 
testing at ESPs higher than representative for WSHPs results in 
efficiency ratings that underestimate fan power needed to operate at 
zero ESP.
    Regarding comments received about ESP requirements in the revised 
version of ISO 13256-1, DOE acknowledges that Table 1 of ISO 13256-
1:2021 does include minimum ESPs for all fan motor types, and that 
those minimum ESPs are generally consistent with the values in Table 7 
of AHRI 340/360-2022, albeit with slight differences due to rounding. 
However, ISO 13256-1:2021 does not include an upper tolerance on ESP 
(i.e., tests can still be conducted at any ESP above the minimum) and 
maintains the fan power correction to adjust down to zero ESP. Again, 
DOE tentatively finds that its proposed approach based on AHRI 340/360-
2022 would produce results more representative of an average WSHP use 
cycle, so the Department is not proposing to use ISO 13256-1:2021 in 
this context.
    Because the fan power adjustment method used in ISO 13256-1:1998 
and ISO 13256-1:2021 does not capture the fan power to overcome ESP, 
and underestimates the fan power needed to operate at zero ESP for many 
units (as determined from DOE's testing and examination of rated ESPs 
from STI), DOE has tentatively concluded that ratings based on 
performance at a representative ESP requirement (as is the case in AHRI 
340/360-2022) are more representative of the total fan power that would 
be consumed in field installations.
    The minimum ESP requirements specified in Table 7 of AHRI 340/360-
2022 align with the minimum ESP requirements specified in Table B2 of 
the AHRI WSHP/Geothermal Operations Manual and are generally consistent 
with the minimum ESPs specified in Table 1 of ISO 13256-1:2021, with 
slight differences due to rounding. Based on the inclusion of similar 
minimum ESP requirements in the AHRI WSHP/Geothermal Operations Manual 
and ISO 13256-1:2021, DOE has tentatively concluded that the minimum 
ESP requirements specified in AHRI 340/360-2022 are representative of 
water-loop WSHP field installations.
    To account for the impacts of ESP typically encountered in the 
field, DOE is proposing provisions to reflect fan power to overcome a 
representative ESP when calculating efficiency. As per the discussion 
in this section and in section III.D.2 of this NOPR, DOE has 
tentatively determined that to best reflect field operation, WSHPs 
should be tested with minimum ESPs; the power for overcoming ESP should 
be included in efficiency calculations; and all equipment should be 
tested with an ESP upper tolerance. Therefore, DOE has tentatively 
determined that for WSHPs the method in AHRI 340/360-2022 is more 
representative of field energy use than the methods used in ISO 13256-
1:1998 or ISO 13256-1:2021. As such, DOE is proposing to adopt AHRI 
340/360-2022 for WSHPs, including section 6.1.3.3 and Table 7 of AHRI 
340/360-2022, which specify minimum ESPs for ducted units, a tolerance 
on ESP of -0.00/+0.05 in H2O, and no fan power adjustment. 
In the following sections (sections III.F.1.b and III.F.1.b.i of this 
document), DOE provides further detail on proposed provisions for 
setting airflow and ESP for units intended to be installed both with 
and without ducts.
    Regarding comments received about WSHPs with higher-static fan 
motors, DOE is proposing an approach for

[[Page 53322]]

representations and enforcement of units with non-standard indoor fan 
motors (i.e., more powerful fan motors intended for operation with ESPs 
higher than the ESP requirements in the test procedure). This approach 
would allow for an individual model with a non-standard indoor fan 
motor to be included in the same basic model as an individual model 
with a standard indoor fan motor, with the rating based on performance 
with the standard indoor fan motor, as long as the non-standard indoor 
fan motor has the same or better relative efficiency performance as 
compared to the standard motor. DOE has tentatively concluded that this 
proposed approach addresses the concerns raised by commenters that ESP 
requirements would penalize units with higher-static indoor fan motors. 
Section III.G.3 of this NOPR includes additional discussion on DOE's 
proposed approach for non-standard indoor fan motors.
    Regarding comments received about the AHRI WSHP/Geothermal 
Operations Manual, DOE notes that the Operations Manual is not 
incorporated by reference in the DOE test procedure and is not 
referenced in ASHRAE Standard 90.1. Therefore, the provisions included 
in the AHRI WSHP/Geothermal Operations Manual are not reflected in the 
current DOE test procedure. However, DOE has nonetheless reviewed the 
AHRI WSHP/Geothermal Operations Manual as part of its consideration of 
potential amended test procedure provisions in this NOPR. DOE notes 
that Table B2 of the AHRI WSHP/Geothermal Operations Manual does 
specify ESP requirements that align with the ESP requirements specified 
in Table 7 of AHRI 340/360-2022; however, the ESP requirements in the 
AHRI WSHP/Geothermal Operations Manual only apply to ducted units with 
ECM fan motors. DOE has tentatively concluded that specification of ESP 
requirements would provide for more representative ratings for all 
ducted WSHPs, not just units with ECM fan motors. Additionally, DOE 
notes that section A5 of the AHRI WSHP/Geothermal Operations Manual 
limits the fan power correction to no more than 3 percent of the 
measured cooling capacity. However, because the fan power correction is 
applied to both the capacity and total power when calculating EER or 
COP, the effect of a fan power correction of 3 percent on the 
calculated efficiency would be significantly more than 3 percent. 
Further, as discussed, DOE has tentatively concluded that ratings based 
on minimum ESP requirements would be more representative than ratings 
based on zero ESP (developed using the fan power correction). For these 
reasons, DOE is not proposing to incorporate by reference or otherwise 
adopt the AHRI WSHP/Geothermal Operations Manual as part of the DOE 
WSHP test procedure.
    Regarding comments received about coil-only units, DOE has 
identified at least one coil-only unit that would meet the definition 
of a WSHP. In accordance with DOE's proposal to adopt AHRI 340/360-
2022, coil-only WSHPs would be subject to the test provisions for 
setting airflow for coil-only units specified in sections 6.1.3.3 and 
6.1.3.4 of AHRI 340/360-2022.
    Issue 10: DOE requests comment on the proposal to adopt provisions 
from AHRI 340/360-2022 such that testing would be conducted within 
tolerance of the AHRI 340/360-2022 minimum ESP requirements, and 
efficiency ratings would include the fan power measured to overcome the 
tested ESP.
b. Setting Airflow and ESP
    ISO 13256-1:1998 specifies airflow rates in section 4.1.5 of that 
document, including that: (a) non-ducted heat pumps shall be tested at 
airflow rates obtained at zero ESP; (b) ducted heat pumps with internal 
fans or with designated air movers shall be tested at the airflow rates 
obtained at zero ESP or the manufacturer-specified airflow rate, 
whichever is lower, and (c) ducted heat pumps without internal fans 
shall be tested at the manufacturer-specified airflow rate subject to a 
maximum internal pressure drop. Additionally, paragraph (e)(2) of 10 
CFR 431.96 requires that the airflow rate used for testing must be 
specified by the manufacturer in the installation and operation manuals 
being shipped to the commercial customer, and that if a rated air flow 
value for testing is not clearly identified, a value of 400 standard 
cubic feet per minute per ton shall be used.
    ISO 13256-1:1998 does not indicate which speed setting should be 
used to achieve specified airflow for a fan with more than one speed 
setting. Also, in some cases, the airflow rate and pressure conditions 
specified for a given ducted heat pump without an internal fan may not 
be achievable simultaneously. ISO 13256-1:1998 does not provide an 
approach for simultaneously achieving the specified airflow rate and 
pressure conditions in cases where the airflow may not be achievable 
below the maximum internal pressure drop. In the June 2018 RFI, DOE 
requested comment on whether indoor fans typically have multiple speed 
settings for WSHPs, and if so, how manufacturers choose the speed to 
use during testing. DOE also requested comment on how specified airflow 
is achieved if none of the speed settings produce that airflow at the 
specified internal or external static pressure. 83 FR 29048, 29051 
(June 22, 2018).
    AHRI and WaterFurnace commented that most WSHP fans have at least 
three speeds. (AHRI, No. 12 at p. 7; WaterFurnace, No. 7 at p. 7) Trane 
commented that their company offers single-speed and multi-speed units. 
(Trane, No. 8 at p. 4) AHRI, Trane, and WaterFurnace stated that as 
part of AHRI's certification program, the test facility utilizes the 
blower speed specified by the manufacturer in literature and submission 
data. (AHRI, No. 12 at p. 7; Trane, No. 8 at p. 4; WaterFurnace, No. 7 
at p. 7) AHRI and WaterFurnace further stated that manufacturers select 
an airflow that is advantageous for the specifications they are trying 
to achieve; for example, low airflows are beneficial for humidity 
removal. Id. The commenters also indicated that the AHRI WSHP/
Geothermal Operations Manual specifies steps to be taken if the 
manufacturer's specified airflow is not met with the initial fan 
settings, which include reducing ESP to a minimum value set forth in 
the AHRI WSHP/Geothermal Operations Manual. Id.
    AHRI acknowledged that in some cases, the airflow rate and pressure 
conditions specified by ISO 13256-1:1998 for a given ducted heat pump 
without an internal fan may not be achievable simultaneously. As an 
example, AHRI described a scenario in which the manufacturer-specified 
airflow may not be achievable below the maximum internal pressure drop 
specified in section 4.1.5.3 of ISO 13256-1:1998. AHRI stated that ISO 
13256-1:1998 does not provide an approach for simultaneously achieving 
the specified airflow rate and pressure conditions in such a case. 
(AHRI, No. 12 at p. 7) In such cases, AHRI and WaterFurnace stated that 
provisions in Appendix B of the AHRI WSHP/Geothermal Operations Manual 
are used that permit a tolerance for achieving the specified airflow 
within 10 percent of the manufacturers specified flow rate. (AHRI, No. 
12 at p. 7; WaterFurnace, No. 7 at p. 6)
    On this topic, DOE notes that the provisions of ISO 13256-1:2021 
are equivalent to those in ISO 13256-1:1998 for setting airflow of non-
ducted units and ducted units without internal fans. For ducted units 
with internal fans, ISO 13256-1:2021 provides additional specifications 
beyond those in ISO 13256-1:1998. Table 1 of ISO 13256-1:2021 provides 
minimum ESP values and explains that airflow should be set

[[Page 53323]]

as specified by the manufacturer with an ESP greater than or equal to 
the minimum ESP value set forth in ISO 13256-1:2021. For units with 
non-constant airflow fans and adjustable speed, ISO 13256-1:2021 states 
that the speed may be adjusted as needed to the lowest speed that 
provides at least the minimum ESP at the specified airflow rate. In 
cases where the airflow rate cannot be maintained within tolerance with 
an ESP greater than or equal to the minimum ESP, the test must be run 
at the airflow achieved with an ESP equal to the minimum ESP.
    As noted in section III.F.1.a of this document, DOE is proposing to 
adopt the minimum ESP requirements in Table 7 of AHRI 340/360-2022 and 
condition tolerances in Table 6 of AHRI 340/360-2022. For the reasons 
that follow, DOE has tentatively concluded that AHRI 340/360-2022 is 
superior to available alternatives in terms of these objectives. To 
start, DOE has tentatively determined that more specification than 
provided in ISO 13256-1:1998 is needed to ensure consistent and 
repeatable setting of airflow and ESP for testing, thereby ensuring the 
representativeness of the results. For example, ISO 13256-1:1998 does 
not specify what to do in certain circumstances when instructions 
provided are unclear or conflict (e.g., if no fan control setting is 
certified and multiple combinations of ESP and fan speed can provide 
the manufacturer-specified airflow). Although ISO 13256-1:2021 provides 
more specification than ISO 13256-1:1998 for setting airflow in ducted 
units with an internal fan, it still does not address situations in 
which instructions are missing, are unclear, or conflict. In addition, 
neither version of the ISO test procedure specifies an upper tolerance 
on ESP for ducted units. As such, further detail than what is provided 
in ISO 13256-1:1998 and ISO 13256-1:2021 is warranted. Furthermore, the 
AHRI WSHP/Geothermal Operations Manual includes some provisions on fan 
settings, but these provisions are likewise insufficient for setting 
airflow and ESP with minimum ESPs and condition tolerances, as that 
manual relies on communication and agreement between the manufacturer 
and AHRI in situations in which both ESP and airflow tolerances cannot 
be met. Such approach is inappropriate in a regulatory context.
    Therefore, as stated previously in this NOPR, DOE is proposing to 
incorporate by reference AHRI 340/360-2022, including adoption of 
sections 6.1.3.3 through 6.1.3.5, which specify a 3 percent condition 
tolerance for airflow rate, a -0.00/+0.05 in H2O condition 
tolerance for ESP, and instructions on setting airflow and ESP during 
testing. These sections additionally provide guidance on what to do 
during testing if one or both of the conditions cannot be met. DOE 
preliminarily finds that these provisions would improve test 
repeatability, provide test conditions that are more representative of 
field operation, and appropriately address the issue where none of the 
speed settings produce the specified airflow at the specified internal 
or external static pressure.
    DOE notes, however, that the relevant provisions in AHRI 340/360-
2022 were generally developed for ducted units with continuously 
variable-speed fans. Accordingly, additional provisions specific to 
testing ducted units with discrete-step fans and non-ducted units are 
necessary. The following sub-sections discuss the proposed additional 
provisions for such WSHPs.
    Issue 11: DOE requests comment on the proposed adoption of 
provisions from AHRI 340/360-2022 for setting airflow and ESP for WSHP 
testing.
(i) Ducted Units With Discrete-Step Fans
    Many ducted WSHPs have fans with discrete steps in speed. In 
situations where both airflow and ESP tolerances cannot be met, the 
instructions in section 6.1.3.5 of AHRI 340/360-2022 can result in 
ducted units with discrete-step fans operating with ESPs that are 
higher than the tolerance on the ESP requirements due to the difference 
in fan speed between each step.
    Section 6.1.3.5 of AHRI 340/360-2022 specifies that the measured 
airflow during test must be within 3 percent of the rated airflow and 
that the ESP during test must be within -0.00/+0.05 in H2O 
of the minimum ESP specified in Table 6. Section 6.1.3.5.2.4 specifies 
that for two adjacent fan control settings, if the lower setting is too 
low (such that ESP or airflow are lower than the tolerance range) and 
the higher setting is too high (such that ESP or airflow are higher 
than the tolerance range), then the higher fan control setting should 
be used. At this higher fan control setting, section 6.1.3.5.2.4 
specifies to maintain airflow within tolerance, which would result in 
an ESP higher than the +0.05 in H2O tolerance. However, 
WSHPs with discrete-step fans may have a limited number of fan control 
settings, such that testing at the higher fan speed in this case may 
result in testing with an ESP that significantly exceeds the minimum 
ESP requirement. For such units, in a case in which operating at the 
lower fan control setting with the ESP in tolerance results in an 
airflow slightly lower than 97 percent of the rated airflow, it would 
be more representative to test at the lower fan control setting with 
the airflow slightly below the 97 percent tolerance, rather than test 
at the higher fan control setting with an ESP potentially significantly 
exceeding the minimum ESP requirement. In such a case, the industry 
test procedures for SPVUs (AHRI 390-2021; section 5.7.3.4.1.4) and CAC/
HPs (AHRI 210/240-2023; section 6.1.5.1.6) allow airflow to drop to 90 
percent of the rated airflow while maintaining ESP within tolerance. 
DOE has tentatively concluded that adopting this approach for WSHPs 
would result in testing at conditions more representative of field 
applications.
    Therefore, for ducted units with discrete-step fans, DOE is 
proposing in section 3.2 of proposed appendix C1 instructions for 
setting the fan speed in the scenario in which: (1) tolerances for 
airflow and ESP cannot be met simultaneously, and (2) adjacent fan 
control settings result in airflow or ESP too low at the lower fan 
control setting and too high at the higher fan control setting. These 
proposed instructions specify to exclude sections 6.1.3.5.2.4 and 
6.1.3.5.3.2.3 of AHRI 340/360-2022, and to allow airflow to drop to 90 
percent of the specified airflow rate while maintaining ESP within 
tolerance. If ESP cannot be maintained within tolerance at 90 percent 
of the specified airflow rate, the proposed instructions specify to use 
the next highest fan speed and allow ESP to exceed the tolerance while 
maintaining airflow within tolerance.
    Issue 12: DOE requests comment on its proposed instructions for 
setting airflow and ESP for ducted WSHP units with discrete-step fans.
(ii) Non-Ducted Units
    DOE is aware that some WSHPs may be installed without indoor air 
distribution ducts in the field. Depending on the type of installation, 
the test method specified in ISO 13256-1:1998 differs; section 4.1.2 of 
ISO 13256-1:1998 specifies provisions for WSHPs installed without 
ducts, and section 4.1.3 of the standard specifies provisions for WSHPs 
installed with ducts. ISO 13256-1:1998 does not specify how to 
distinguish whether a unit is ducted or non-ducted. The provisions of 
ISO 13256-1:2021 are the same as those of ISO 13256-1:1998 in this 
regard.
    In the June 2018 RFI, DOE requested comment on the physical 
characteristics that distinguish ducted and non-ducted WSHPs. DOE also 
requested comment

[[Page 53324]]

on whether any WSHP models can be installed either with or without 
indoor distribution ducts, and if such models exist, DOE requested 
comment on whether manufacturers test these models to the non-ducted 
provisions in section 4.1.2 of ISO 13256-1:1998 or the ducted 
provisions in section 4.1.3 of ISO 13256-1:1998, or whether these 
models are tested using both provisions of section 4.1.2 and 4.1.3. 83 
FR 29048, 29050-29051 (June 22, 2018).
    In response to DOE's request for information, AHRI and WaterFurnace 
commented that WSHPs may be designed for use either with or without 
indoor air distribution ducts, and that while the specified test set-
ups are different, the non-ducted test simulates the conditions of the 
ducted test using a hood with zero static to accumulate the supply air 
for volumetric and enthalpy measurements. (AHRI, No. 12 at pp. 6-7; 
WaterFurnace, No. 7 at pp. 5-6)
    AHRI and WaterFurnace also commented that the majority of WSHPs are 
designed for use with ductwork but that there are some console units 
designed to ``free blow'' into the space with no ductwork at zero ESP. 
(AHRI, No. 12 at pp. 6-7; WaterFurnace, No. 7 at pp. 5-6) AHRI added 
that such non-ducted WSHPs typically include a tangential blower 
(similar to packaged terminal air conditioners) meant for low-static 
operation and free discharge into the conditioned space. (AHRI, No. 12 
at pp. 6-7) Trane commented that motor horsepower and fan size are 
designed to deliver zero ESP for non-ducted units and that units that 
are required to be ducted will require a different motor horsepower and 
fan size. (Trane, No. 8 at p. 4)
    Additionally, AHRI and Trane pointed out that WSHPs are certified 
to AHRI as either ``ducted'' or ``non-ducted'' and that the equipment 
is tested to the appropriate section of ISO 13256-1:1998. AHRI and 
WaterFurnace commented that there are no known WSHP models designed for 
both ducted and non-ducted application. (AHRI, No. 12 at pp. 6-7; 
WaterFurnace, No. 7 at pp. 5-6) In contrast, Trane stated that although 
it does not offer any equipment that can be installed as either ducted 
or non-ducted, there is a selection of WSHP equipment that is designed 
for both ducted and non-ducted applications. (Trane, No. 8 at pp. 3-4)
    Consistent with AHRI's, WaterFurnace's, and Trane's comments, DOE 
has identified some WSHPs, marketed as ``console units,'' which would 
operate without a duct. As noted previously, AHRI 340/360-2022 does not 
have any instructions for setting up airflow and ESP for non-ducted 
units. (AHRI 340/360-2022 is the industry test procedure for testing 
CUACs and there are no non-ducted CUACs.) Section 4.1.5 of ISO 13256-
1:1998 and section 5.1.5 of ISO 13256-1:2021 include provisions for 
setting airflow for non-ducted units at zero ESP, but the provisions in 
ISO 13256-1:1998 and ISO 13256-1:2021 do not specify the settings to 
use or how to address situations in which test procedure instructions 
are missing or conflict (also see discussion in section III.F.1.b of 
this NOPR). Therefore, DOE has tentatively concluded that specific 
provisions for non-ducted WSHPs are warranted.
    To address testing of non-ducted WSHPs, DOE proposes separate 
provisions for setting airflow and ESP for non-ducted units in section 
3.1 of proposed appendix C1. Consistent with ISO 13256-1:1998 and ISO 
13256-1:2021, DOE proposes that non-ducted units be tested at zero ESP, 
because non-ducted units would not be installed with ductwork in the 
field. DOE proposes that these provisions would apply to all units that 
are not configured exclusively for delivery of conditioned air to the 
indoor space without a duct(s). Units that are configured for delivery 
of conditioned air to the indoor space without a duct(s) would be 
required to use the provisions for setting airflow and ESP in section 
6.1.3 of AHRI 340/360-2022 and section 3.2 of proposed appendix C1, as 
applicable.
    DOE is proposing in section 3.1 of proposed appendix C1 that WSHP 
units that are not configured exclusively for delivery of conditioned 
air to the indoor space without a duct(s) would be tested with a target 
ESP of 0.00 in H2O (consistent with ISO 13256-1:1998 and ISO 
13256-1:2021) within a tolerance of -0.00/+0.05 in H2O in 
place of the ESP specified in Table 7 of AHRI 340/360-2022 (because the 
ESP requirements in AHRI 340/360-2022 are intended to reflect the 
pressure drop in ductwork for ducted units). The proposed ESP tolerance 
for non-ducted units aligns with the tolerance for ducted units in AHRI 
340/360-2022. Instead of the instructions for setting airflow and ESP 
in section 6.1.3.5 of AHRI 340/360-2022, DOE proposes that if both the 
ESP and airflow cannot be simultaneously maintained within tolerance 
for any test, to maintain the ESP within the required tolerance and use 
an airflow as close to the target value as possible (i.e., prioritize 
maintaining ESP in tolerance over maintaining airflow in tolerance). 
This is because testing an ESP of more than 0.05 in H2O 
would not be representative for a non-ducted unit which would not be 
installed with ductwork in the field. Finally, DOE proposes that if an 
airflow out of tolerance is used for the full-load cooling test, then 
the measured full-load cooling airflow is to be used as the target 
airflow for all subsequent tests that call for the full-load cooling 
airflow within a tolerance of +/-3 percent. These provisions are 
similar to those included for testing non-ducted units in other 
industry test standards for comparable categories of commercial air 
conditioners and heat pumps, such as AHRI 390-2021 for testing SPVUs.
    DOE has tentatively determined that these provisions would provide 
a representative and repeatable test procedure for non-ducted WSHPs, 
and that they would be appropriate for testing WSHPs because they are 
the generally accepted industry method used for testing similar 
equipment such as SPVUs. This proposed approach remedies some of the 
shortcomings identified with the current WSHP test procedure which 
incorporates by reference ISO 13256-1:1998.
    Issue 13: DOE requests comment on its proposal for setting airflow 
and ESP for non-ducted WSHP units.
2. Capacity Measurement
a. Primary and Secondary Methods
    The current DOE test procedure, through adoption of section 6.1 of 
ISO 13256-1:1998, specifies that total cooling and heating capacities 
are to be determined by averaging the results obtained using two test 
methods: the liquid enthalpy test method for the liquid side tests and 
the indoor air enthalpy test method for the air side tests. For non-
ducted equipment, section 6.1 of ISO 13256-1:1998 includes an option 
for conducting the air-side tests using the calorimeter room test 
method instead of the air enthalpy test method. Section 6.1 of ISO 
13256-1:1998 also specifies that, for a test to be valid, the results 
obtained by the two methods used must agree within 5 percent.
    In the June 2018 RFI, DOE discussed how ANSI/ASHRAE 37-2009 is 
similar to the test method in ISO 13256-1:1998, and that DOE was 
considering whether testing to ANSI/ASHRAE 37-2009 would be appropriate 
for WSHPs. DOE further discussed how ANSI/ASHRAE 37-2009 requires two 
capacity measurements for units with cooling capacity less than 135,000 
Btu/h; the first method of measurement (i.e., the primary method) is 
used as the determination of the unit's capacity, while the second 
measurement (i.e., the secondary method) is used to confirm

[[Page 53325]]

rather than to be averaged with the primary measurement (see section 
10.1 and Table 1 of ANSI/ASHRAE 37-2009). 83 FR 29048, 29052 (June 22, 
2018).
    In the June 2018 RFI, DOE requested information on whether one of 
the two capacity measurements prescribed in ISO 13256-1:1998 gives a 
consistently higher or lower result than the other, or whether one of 
the methods can be considered more accurate for a range of different 
WSHP configurations and models. Id. Additionally, DOE requested comment 
on whether the ANSI/ASHRAE 37-2009 approach for determination of rated 
capacity (i.e., using the primary method's measurement as the rated 
capacity rather than averaging the two capacity measurements) would 
result in more representative ratings than the ISO 13256-1:1998 
approach. Id.
    Trane commented that the capacity value measured by the liquid 
enthalpy method is generally higher than the value measured by the 
indoor air enthalpy method, stating that air-side measurements have 
more opportunity for losses than water-side measurements. (Trane, No. 8 
at p. 5) AHRI and WaterFurnace commented that the water side test is 
generally simpler to conduct and also more accurate than the air 
enthalpy method, because the uncertainties of measurement are much 
lower in the water-side calculations. (AHRI, No. 12 at p. 13; 
WaterFurnace, No. 7 at p. 11)
    AHRI, Trane, and WaterFurnace recommended continuing to use the 
average of the air-side and water-side measurements as the basis for 
capacity ratings. (AHRI, No. 12 at p. 13; Trane, No. 8 at p. 5; 
WaterFurnace, No. 7 at p. 11) AHRI and WaterFurnace stated that the 
current approach in ISO 13256-1:1998 represents a compromise that helps 
ensure best testing procedures. (AHRI, No. 12 at p. 13; WaterFurnace, 
No. 7 at p. 11) AHRI argued that the ANSI/ASHRAE 37-2009 approach does 
not yield more representative ratings compared to the ISO 13256-1:1998 
method. (AHRI, No. 12 at p. 13) Trane further asserted that the average 
of the methods is more accurate than the measurement from either single 
method alone. (Trane, No. 8 at p. 5) AHRI and WaterFurnace also stated 
that ANSI/ASHRAE 37-2009 does not include the liquid enthalpy method of 
test required on the source side for all WSHPs. (AHRI, No. 12 at p. 13; 
WaterFurnace, No. 7 at p. 10)
    In response, DOE notes first that the capacity measurement 
provisions in section 7.1 of ISO 13256-1:2021 differ from those in 
section 6.1 of ISO 13256-1:1998 in several ways. Instead of averaging 
the two capacity measurements, section 7.1 of ISO 13256-1:2021 
specifies that the capacity rating is equal to the value determined 
from the air side (referred to as the load side in ISO 13256-1:2021), 
consistent with the approach used in section 10.1.2 of ANSI/ASHRAE 37-
2009. ISO 13256-1:2021 also does not allow use of the calorimeter 
method in place of the indoor air enthalpy method for measuring 
capacity on the load side, but section 7.1 of ISO 13256-1:2021 allows 
use of the refrigerant enthalpy method for configurations that cannot 
use the indoor air enthalpy method. Section 7.1 of ISO 13256-1:2021 
continues to require the liquid enthalpy method for measuring capacity 
on the liquid side (referred to as the source side in ISO 13256-
1:2021). Section 7.1 of ISO 13256-1:2021 also continues to require the 
two capacity measurements to agree within 5 percent for the test to be 
valid.
    As discussed in section III.D.2 of this NOPR, DOE proposes to adopt 
specific sections of AHRI 340/360-2022 for use in the WSHP test 
procedure, including section E6, which specifies test methods for 
capacity measurement. Section E6.1 of AHRI 340/360-2022 requires use of 
the indoor air enthalpy method specified in section 7.3 of ANSI/ASHRAE 
37-2009 as the primary method for capacity measurement. This is the 
measurement used to determine capacity, as required in section 10.1.2 
of ANSI/ASHRAE 37-2009. Section E6.2.2 of AHRI 340/360-2022 requires 
use of one of the applicable ``Group B'' methods specified in Table 1 
of ANSI/ASHRAE 37-2009 as a secondary method for capacity measurement. 
The group B methods that are applicable to WSHPs are the outdoor liquid 
coil method (similar to the liquid enthalpy method included in the 1998 
and 2021 versions of ISO 13256-1), the refrigerant enthalpy method, and 
the compressor calibration method. Section E6.4.2 of AHRI 340/360-2022 
requires that the primary and secondary measurements match for full-
load cooling and heating tests, within 6 percent of the primary 
measurement. No match is required between primary and secondary 
measurements for part-load cooling tests.
    Regarding commenters' claims that ANSI/ASHRAE 37-2009 does not 
include the liquid enthalpy method of test required on the source side 
for all WSHPs, as discussed, ANSI/ASHRAE 37-2009 does include a liquid 
enthalpy method of test. The liquid enthalpy method is referred to as 
the outdoor liquid coil method in section 7 of ANSI/ASHRAE 37-2009, and 
it provides a measurement of liquid enthalpy that is similar to the 
measurement provided by the liquid enthalpy method in normative 
appendix C of ISO 13256-1:1998. As discussed, Table 1 of ANSI/ASHRAE 
37-2009 specifies three secondary capacity measurement methods (i.e., 
outdoor liquid coil, refrigerant enthalpy, and compressor calibration 
methods) that may be used to conduct the secondary measurements that 
are required for testing WSHPs with cooling capacity less than 135,000 
Btu/h, rather than requiring the outdoor liquid coil for all water-
source units (as is the case in section 6.1 of ISO 13256-1:1998). Table 
1 of ANSI/ASHRAE 37-2009 also specifies the applicability of each 
secondary capacity method based on the configuration of the unit being 
tested. This specification of applicable secondary capacity measurement 
methods in ANSI/ASHRAE 37-2009 ensures that the chosen secondary 
capacity measurement is accurate because the outdoor liquid coil method 
in ANSI/ASHRAE 37-2009 is not applicable for certain unit 
configurations in which the compressor heat would not be sufficiently 
accounted for. Specifically, section 7.6.1.2 and note g to Table 1 of 
ANSI/ASHRAE 37-2009 specify that the outdoor liquid coil method may not 
be used if the system has a compressor that is ventilated by outdoor 
air or a remote outdoor compressor that is not insulated per section 
7.6.1.2 of ANSI/ASHRAE 37-2009. Section III.F.2.b of this NOPR includes 
further discussion on this topic.
    As part of DOE's proposal generally to adopt the test provisions in 
section E6 of AHRI 340/360-2022, DOE is proposing to adopt the 
provisions for measuring capacity in AHRI 340/360-2022 instead of those 
in section 6.1 of ISO 13256-1:1998. Using the indoor air enthalpy 
measurement as the measurement of capacity ensures that actual output 
of the WSHP--the cooling or heating of air--is used as the measure of 
capacity. The approach used in section 6.1 of ISO 13256-1:1998, in 
which the indoor air enthalpy measurement is averaged with the liquid 
enthalpy measurement, has the potential to result in capacity values 
that are higher than the actual delivered capacity because of heat 
transfer to/from the ambient air (either through heat transfer through 
the WSHP cabinet walls or air leakage). This potential is consistent 
with Trane's comment that the capacity value measured by the liquid 
enthalpy method is generally higher than the value measured by the 
indoor air enthalpy method. In addition,

[[Page 53326]]

the approach used in section E6 of AHRI 340/360-2022 is consistent with 
the approach in section 7.1 of ISO 13256-1:2021, in that the indoor air 
enthalpy measurement is used as the capacity measurement in ISO 13256-
1:2021. It is also consistent with the industry test procedures for 
other categories of air conditioning and heating equipment (e.g., AHRI 
Standard 1230, AHRI Standard 390, and AHRI Standard 210/240). 
Therefore, DOE has tentatively concluded that it is more representative 
for the capacity rating of WSHPs to be determined with the indoor air 
enthalpy method, and for the secondary measurement to serve only as a 
verification of the indoor enthalpy measurement, rather than being 
averaged with the indoor air enthalpy method result to determine the 
capacity rating.
    The proposed provisions do not permit use of the calorimeter method 
or refrigerant enthalpy method in place of the indoor enthalpy method, 
which is allowed in section 6.1 of ISO 13256-1:1998 and section 7.1 of 
ISO 13256-1:2021. However, DOE has tentatively concluded that 
alternatives to the indoor air enthalpy method are not necessary 
because DOE is not aware of any WSHPs that are unable to use the indoor 
enthalpy method as specified in ANSI/ASHRAE 37-2009 (with additional 
provisions in AHRI 340/360-2022).
    The proposed provisions also allow a difference in capacity 
measurements of up to 6 percent in section E6.4.2 of AHRI 340/360-2022 
instead of the 5 percent allowed in section 6.1 of ISO 13256-1:1998. 
DOE has tentatively concluded that this reduces burden while still 
ensuring accurate measurements of indoor air enthalpy. Once again, this 
proposal is consistent with the industry test procedures for other 
categories of air conditioning and heating equipment (e.g., AHRI 
Standard 1230, AHRI Standard 390, and AHRI Standard 210/240).
    Issue 14: DOE requests comment on its proposed approach to adopt 
the provisions in AHRI 340/360-2022 and ANSI/ASHRAE 37-2009 regarding 
primary and secondary capacity measurements.
b. Compressor Heat
    DOE has identified split-system WSHPs available on the market. For 
at least one of these split systems WSHPs, the unit containing the 
compressor is intended for either indoor or outdoor installation. The 
installed location of the compressor, in relation to the conditioned 
space and other system components, impacts the capacity of a WSHP 
system and the provisions necessary for accurately measuring system 
capacity due to the generation of heat during compressor operation.
    As discussed in section III.F.2.a of this NOPR, the current DOE 
test procedure, through adoption of ISO 13256-1:1998, requires use of 
two methods to measure space-conditioning capacity provided by a WSHP. 
One of these methods, the indoor air enthalpy method (see normative 
annex B of ISO 13256-1:1998), measures capacity directly by measuring 
mass flow and enthalpy change of the indoor air.\21\ The second method, 
the liquid enthalpy test method (see normative annex C of ISO 13256-
1:1998), measures heat transferred at the liquid coil. The liquid 
enthalpy measurement is adjusted by adding or subtracting the total 
unit input power (including the compressor input power) from the 
measured liquid side capacity in the heating or cooling mode tests, 
respectively, using the equations in sections C3.1 and C3.2 of ISO 
13256-1:1998.
---------------------------------------------------------------------------

    \21\ The alternative calorimeter room test method (see normative 
annex E of ISO 13256-1:1998), allowed to be used instead of the 
indoor air enthalpy method for non-ducted WSHPs, also measures 
indoor space-conditioning capacity directly.
---------------------------------------------------------------------------

    The liquid enthalpy adjustment in sections C3.1 and C3.2 of ISO 
13256-1:1998 assumes that all compressor heat is absorbed and 
ultimately transferred to the conditioned space, thereby increasing 
heating capacity or decreasing cooling capacity. However, this fails to 
account for any heat transferred from the compressor or other 
components to their surroundings that does not contribute to space 
conditioning. For example, in the case of a split-system WSHP with an 
uninsulated compressor/liquid coil section installed outdoors, the air 
that absorbs compressor heat would not directly affect the conditioned 
space. In this case, adding or subtracting the entire compressor input 
power to or from the capacity calculated based on liquid temperature 
change likely overestimates the impact of compressor power input on the 
indoor-side capacity that is calculated using the liquid enthalpy-based 
method.
    In the June 2018 RFI, DOE requested comment on whether there are 
split-system WSHP models on the market for which the unit containing 
the compressor is intended only for outdoor installation or only for 
indoor installation. DOE further requested comment on manufacturers' 
practices for testing split-system WSHPs for which the compressor is 
not housed in the section containing the indoor refrigerant-to-air 
coil, including which test rooms are used for the compressor section, 
and whether any adjustments are made to properly account for the 
compressor heat. 83 FR 29048, 29053 (June 22, 2018).
    In response to DOE's requests for comment, AHRI, Trane, and 
WaterFurnace commented that accounting for compressor heat would not be 
a relevant issue because there are very few, if any, split-system WSHPs 
in the commercial market. (AHRI, No. 12 at p. 13; Trane, No. 8 at p. 5; 
WaterFurnace, No. 7 at pp. 11-12) The CA IOUs commented that, based on 
the AHRI directory, 90 percent of WSHPs are single-package units. (CA 
IOUs, No. 9 at p. 2)
    As stated previously, DOE has identified a number of split-system 
WSHPs, several of which are certified in the DOE Compliance 
Certification Database, and the Federal test procedure \22\ applies to 
any WSHP that meets DOE's definition of a WSHP. Further, because split-
system WSHPs are available on the market, test procedure provisions are 
needed for testing them, regardless of their share of the WSHP market.
---------------------------------------------------------------------------

    \22\ Currently, the DOE test procedure applies to all WSHPs with 
a capacity less than 135,000 Btu/h. However, DOE is proposing in 
section III.A of this NOPR to increase the scope of the Federal test 
procedure to include all WSHPs with a capacity less than 760,000 
Btu/h.
---------------------------------------------------------------------------

    Sections D.4 and D.5 of ISO 13256-1:2021 use the same adjustment of 
the liquid enthalpy method as sections C3.1 and C3.2 of ISO 13256-
1:1998. Thus, ISO 13256-1:2021 provides no additional methods to 
address compressor heat for split systems with the compressor in the 
liquid coil section.
    As discussed in section III.D.2 of this NOPR, DOE proposes to adopt 
specific sections of AHRI 340/360-2022 in its test procedure for WSHPs. 
AHRI 340/360-2022 in turn references the test method in ANSI/ASHRAE 37-
2009. Sections 6.1.3 and 6.1.5 of ANSI/ASHRAE 37-2009 contain 
provisions for addressing compressor heat in the indoor air enthalpy 
method that are similar to the provisions in sections F7.3 and F7.5 of 
ISO 13256-1:1998. For secondary capacity measurements, however, ANSI/
ASHRAE 37-2009 has provisions that go beyond the provisions in ISO 
13256-1:1998 to ensure that capacity is measured more accurately than 
it is by ISO 13256-1:1998, as discussed in the following paragraphs.
    Section 7.6 of ANSI/ASHRAE 37-2009 includes a liquid enthalpy 
measurement method (referred to as the

[[Page 53327]]

``outdoor liquid coil method'' and applicable to both single-package 
units and split systems) that is similar to the method in normative 
annex C of ISO 13256-1:1998 in that it adjusts the liquid enthalpy 
measurement by the total input power of the WSHP. For split-system 
WSHPs, ANSI/ASHRAE 37-2009 includes the outdoor liquid coil method, the 
refrigerant enthalpy method, and the compressor calibration method as 
options for conducting the secondary measurements that are required for 
testing WSHPs with cooling capacity less than 135,000 Btu/h. However, 
ANSI/ASHRAE 37-2009 limits use of the outdoor liquid coil method so 
that it does not apply for certain unit configurations in which the 
compressor heat would not be sufficiently accounted for. Specifically, 
Section 7.6.1.2 and note g to Table 1 of ANSI/ASHRAE 37-2009 specify 
that the outdoor liquid coil method may not be used if the system has a 
compressor that is ventilated by outdoor air or a remote outdoor 
compressor that is not insulated per section 7.6.1.2 of ANSI/ASHRAE 37-
2009. These limits on the applicability of the outdoor liquid coil 
method in ANSI/ASHRAE 37-2009 minimize discrepancy between measurements 
from the indoor air enthalpy method and liquid coil method by ensuring 
that either: (1) compressor heat is captured in indoor air enthalpy 
measurements, or (2) compressor heat loss to outdoor air is minimal 
because the compressor is sufficiently insulated.
    For split-system WSHPs for which the outdoor liquid coil method in 
ANSI/ASHRAE 37-2009 cannot be used (i.e., the system has a compressor 
that is ventilated by outdoor air or a remote outdoor compressor that 
is not insulated per section 7.6.1.2 of ANSI/ASHRAE 37-2009), ANSI/
ASHRAE 37-2009 requires the use of either the refrigerant enthalpy 
method specified in section 7.5 of ANSI/ASHRAE 37-2009 or the 
compressor calibration method specified in section 7.4 of ANSI/ASHRAE 
37-2009. For both of these methods, measured capacity is adjusted by 
only the input power of the indoor section of the WSHP, and not the 
total input power. Therefore, for both methods, the compressor heat 
lost to outdoor air from a remote outdoor compressor or compressor 
ventilated by outdoor air would appropriately be excluded from capacity 
measurements, similar to the indoor air enthalpy method. Therefore, for 
WSHPs with those configurations, the refrigerant enthalpy method and 
compressor calibration method specified in sections 7.5 and 7.4 
(respectively) of ANSI/ASHRAE 37-2009 would provide a more 
representative result as compared to the approach used in normative 
annex C of ISO 13256-1:1998 (i.e., liquid enthalpy method).
    Based on the discussion in the prior paragraphs, DOE tentatively 
concludes that the proposed test procedure would provide an accurate 
secondary measure of capacity for all equipment configurations and 
would provide a more representative secondary measure of capacity than 
ISO 13256-1:1998 or ISO 13256-1:2021 for split systems with the 
compressor mounted in the outdoor section.
3. Cyclic Degradation
    As discussed in section III.D.2 of this NOPR, DOE proposes to adopt 
specific sections of AHRI 340/360-2022 in its test procedure for WSHPs, 
including section 6.2.3.2 of that industry standard. Equation 4 in 
section 6.2.3.2 of AHRI 340/360-2022 is used to calculate part-load EER 
for a unit that needs to cycle in order to meet the 75-percent, 50-
percent, and/or 25-percent load conditions required for the IEER 
metric. Cycling is the term used to describe the process in which a 
unit's compressor is repeatedly turned off and on in order to meet a 
load that is lower than the unit's capacity at its lowest compressor 
stage.
    Equation 4 of AHRI 340/360-2022 multiplies only the compressor 
power and condenser section power by the load factor and the 
coefficient of degradation, while the indoor fan power and controls 
power are not multiplied by these variables. This means that equation 4 
of AHRI 340/360-2022 assumes that the indoor fan continues to operate 
when the compressor cycles off. DOE understands that the draft of AHRI 
600 has an equation similar to equation 4 of AHRI 340/360-2022, but the 
equation in draft of AHRI 600 assumes that the indoor fan stops 
operating whenever the compressor cycles off.
    As discussed previously in section III.E.4 of this NOPR, 
stakeholders provided comment regarding the operation of a WSHP, 
including operation of the fan, in modes other than mechanical heating 
and cooling. (AHRI, No. 12 at pp. 4-5, 9; WaterFurnace, No. 7 at pp. 3, 
9; Trane, No. 8 at pp. 2, 5) These comments on fan operation 
specifically referred to operation when there is no heating or cooling, 
but they might also be applicable to the issue of fan operation during 
compressor cycling under part-load conditions. Certain comments 
indicated that it is common for WSHP fans to operate continuously to 
provide air circulation or ventilation air. (AHRI, No. 12 at pp. 4-5; 
WaterFurnace, No. 7 at p. 3) Continuous operation of WSHP fans 
indicates that the fan would continue to run when the compressor cycles 
off.
    In addition, the cyclic degradation approach used in equation 4 of 
AHRI 340/360-2022 is used in the IEER metric for multiple other 
categories of commercial HVAC equipment, indicating that it is common 
for the indoor fan to continue operating while the compressor cycles 
off. AHRI 340/360-2022 is used for testing CUAC/HPs, and equation 4 of 
AHRI 340/360-2022 is equivalent to equation 10 of AHRI 1230-2021 (which 
is used for testing VRF multi-split systems) and equation 3 of AHRI 
390-2021 (which is used for testing SPVUs). These other equipment 
categories typically operate in similar environments to WSHPs (i.e., 
commercial buildings with ventilation air requirements). Similar to 
these other equipment categories, DOE acknowledges that not all WSHPs 
are installed in the same manner, and the Department understands that 
fans operate continuously for many, but not all, installed WSHPs. 
However, comments received suggest that continuous operation of fans is 
representative of operation of many WSHPs, and adopting a cyclic 
degradation approach that assumes continuous fan operation is 
consistent with the IEER approach used for other equipment categories 
that use the IEER metric.
    For the foregoing reasons, DOE has tentatively concluded that the 
cyclic degradation approach in equation 4 of AHRI 340/360-2022 is 
representative of WSHP operation. Therefore, DOE is proposing to adopt 
the approach in AHRI 340/360-2022 in proposed appendix C1. DOE is also 
proposing in section 5.1.2.5.4 of proposed appendix C1 that the same 
approach for cyclic degradation be used when determining IEER through 
interpolation and extrapolation (see discussion in section III.E.1.b of 
this NOPR).
    Due to the nature of the method to determine IEER through the 
proposed interpolation and extrapolation in section 5.1.2 of proposed 
appendix C1, each component of the cyclic degradation equation in 
proposed section 5.1.2.5.4 of proposed appendix C1 (i.e., cooling 
capacity, compressor power, condenser section power, indoor fan power, 
and controls power) would be measured and interpolated from the tested 
EWTs to the IEER EWTs. Furthermore, DOE is proposing that the condenser 
section power for units without integral pumps includes a total pumping 
effect to better account for the energy consumption of liquid pumps

[[Page 53328]]

needed for operation of water-loop WSHP systems. See section III.F.4 of 
this document for more details on the proposed total pumping effect, 
which reflects pump power needed to overcome external static pressure 
in the water loop.
    Issue 15: DOE requests comment on the proposal to adopt the cyclic 
degradation equation specified in section 6.2.3.2 of AHRI 340/360-2022 
for WSHPs, which assumes continuous indoor fan operation when the 
compressor cycles off.
4. Pump Power Adjustment and Liquid External Static Pressure
    As described in section III.D.2 of this NOPR, the efficiency 
calculations in ISO 13256-1:1998 include only the liquid pump power 
required to overcome the internal resistance of the unit; pump power 
required to overcome ESP of the water loop is not included in the 
effective power input. ISO 13256-1:1998 also does not specify a minimum 
liquid ESP during testing for units with integral pumps. For units 
without integral pumps, the pump power adjustment in ISO 13256-1:1998 
estimates pump power at zero liquid external static pressure.
    In the June 2018 RFI, DOE requested information on typical ESP 
values for the liquid pump and if any allowance for external pressure 
drop should be considered in the efficiency metric. 83 FR 29048, 29050 
(June 22, 2018). On this topic, AHRI, Trane, and WaterFurnace stated 
that integral pumps are rare but can be found on some residential 
WSHPs. (AHRI, No. 12 at p. 6; Trane, No. 8, at p. 3; WaterFurnace, No. 
7 at p. 5) AHRI and Trane further stated that because nearly all WSHPs 
do not have an integral pump, pump power to overcome liquid ESP should 
not be considered in the efficiency metric. (AHRI, No. 12 at p. 6; 
Trane, No. 8, at p. 3)
    As discussed previously, since the June 2018 RFI, ISO 13256-1 was 
updated. However, the pump power and liquid ESP provisions in sections 
5.1.4 and 5.1.6 of ISO 13256-1:2021 are the same as those in sections 
4.1.4 and 4.1.6 of ISO 13256-1:1998.
    In response to comments, DOE notes that all WSHPs are installed 
with liquid loops such that a pump (either integral to the WSHP or a 
separate part of the water loop) must overcome external resistance from 
the liquid loop. Therefore, as described in section III.D.2 of this 
NOPR, DOE has tentatively concluded that efficiency metrics that 
reflect the power needed for the liquid pump to overcome a 
representative liquid ESP would be more representative than metrics 
that only include the pump power needed to overcome the internal static 
pressure of the WSHP (as is the case in efficiency metrics determined 
per ISO 13256-1:1998 and ISO 13256-1:2021). DOE has identified several 
WSHPs with integral pumps and has, therefore, tentatively determined 
that provisions for testing units with integral pumps, including liquid 
ESP requirements, are warranted. Even though most WSHP models do not 
include integral pumps, as discussed, such models are installed with 
system pumps that must overcome external resistance of the water loop, 
and thus, including pump power to overcome a representative liquid ESP 
in the efficiency metrics for all WSHPs provides a more representative 
measure of field energy use. DOE has also tentatively determined that 
representative ratings for WSHPs with and without integral pumps should 
reflect the same level of liquid ESP (i.e., WSHPs without integral 
pumps should include a power adder that reflects the pump power needed 
to overcome a level of liquid ESP that aligns with the liquid ESP used 
to test WSHPs with integral pumps). Further, inclusion of pump power to 
overcome a representative liquid ESP provides for more representative 
comparisons with other equipment categories (e.g., air-cooled 
equipment) for which there are no additional power-consuming heat 
rejection components.
    As such, in this NOPR, DOE is proposing provisions to account for 
the power to overcome a representative liquid ESP for WSHPs with and 
without integral pumps. As described in section III.D.3 of this 
document, DOE is proposing generally to incorporate by reference AHRI 
340/360-2022 as the test procedure for WSHPs. Section 6.1.1.7 of AHRI 
340/360-2022 specifies that for WCUACs with cooling capacity less than 
135,000 Btu/h, an adder of 10 W per 1,000 Btu/h cooling capacity must 
be added to the power of WCUACs to account for cooling tower fan motor 
and circulating water pump power consumption. However, AHRI 340/360-
2022 does not specify how to test units with integral pumps. Because 
the provisions in section 6.1.1.7 of AHRI 340/360-2022 do not specify 
the level of liquid ESP that correspond to the specified adder, it is 
unclear what test provisions for units with integral pumps would align 
with the AHRI 340/360-2022 provisions. Further, DOE has tentatively 
concluded that pump power to overcome a representative liquid ESP 
should also be accounted for in WSHPs with cooling capacity greater 
than 135,000 Btu/h.\23\ Given these limitations of AHRI 340/360-2022 in 
terms of addressing WSHPs with integral pumps, DOE reviewed other 
sources with the potential to fill this identified gap.
---------------------------------------------------------------------------

    \23\ Currently, the DOE test procedure applies to all WSHPs with 
a cooling capacity less than 135,000 Btu/h. DOE is proposing in 
section III.A of this NOPR to increase the scope of the DOE test 
procedure to include all WSHPs with a cooling capacity less than 
760,000 Btu/h.
---------------------------------------------------------------------------

    In the course of such review, DOE found that AHRI Standard 920-
2020, ``Performance Rating of Direct Expansion-Dedicated Outdoor Air 
System Units'' (``AHRI 920-2020''), includes a pump power adder 
(referred to as ``water pump effect'' in AHRI 920-2020) for water-
source DOASes without integral pumps. Specifically, section 6.1.6.4 of 
AHRI 920-2020 specifies that the pump power adder is calculated with an 
equation dependent on the water flow rate and liquid pressure drop 
across the heat exchanger, including a term that assumes a liquid ESP 
of 20 ft head. However, AHRI 920-2020 does not include provisions 
specific to testing water-source DOASes with integral pumps. In a test 
procedure final rule for DOASes published in the Federal Register on 
July 27, 2022, DOE adopted the AHRI 920-2020 pump power adder for 
water-source DOASes without integral pumps and adopted an additional 
requirement that water-source DOASes with integral pumps be tested with 
a liquid ESP of 20 ft of water column, consistent with the liquid ESP 
assumed in the AHRI 920-2020 equation for pump power adder for units 
without integral pumps. 87 FR 45164, 45181.
    DOE understands that water-source DOASes and WSHPs are generally 
installed in similar types of commercial building applications that 
include water loops with similar external liquid ESPs (e.g., similar 
water piping). Therefore, DOE has tentatively concluded that the level 
of liquid ESP assumed in the DOAS provisions (i.e., 20 ft of water 
column) would be representative for WSHPs. So that ratings are based on 
the same level of representative liquid ESP for WSHPs with and without 
integral pumps, DOE is proposing to exclude section 6.1.1.7 of AHRI 
340/360-2022 and instead adopt provisions that align with the recently 
adopted provisions for water-source DOASes. Specifically, DOE is 
proposing to require in section 4 of appendix C1 that all WSHPs with an 
integral pump be tested with a liquid ESP of 20 ft of water column, 
with a -0/+1 ft condition tolerance and a 1 ft operating tolerance.
    For units without integral pumps, DOE is proposing to require in 
section

[[Page 53329]]

4.3 of proposed appendix C1 that a ``total pumping effect'' (calculated 
using the same equation as in section 6.1.6.4 of AHRI 920-2020) be 
added to the unit's measured power to account for the pump power to 
overcome the internal static pressure of the unit and a liquid ESP of 
20 ft of water column. Further, DOE is proposing to require in section 
4.4 of appendix C1 that the measured pump power or the pump effect 
addition, as applicable, be included in the condenser section power for 
units of all capacities when performing cyclic degradation during 
calculation of IEER.
    By accounting for liquid ESP conditions encountered during field 
use, DOE has tentatively concluded that the proposals would make the 
resulting efficiency metrics more representative of an average use 
cycle than the efficiency metrics calculated in ISO 13256-1:1998 and 
ISO 13256-1:2021.
    Issue 16: DOE requests comment on the proposed provisions to 
account for pump power to overcome both internal pressure drop and a 
representative level of liquid ESP for WSHPs with and without integral 
pumps. DOE specifically requests comment on the representativeness of 
20 ft of water column as the liquid ESP for WSHPs.
5. Test Liquid and Specific Heat Capacity
    The current DOE WSHP test procedure, through adoption of section 
4.1.9 of ISO 13256-1:1998, requires the test liquid for water-loop heat 
pumps and ground-water heat pumps to be water, and the test liquid for 
ground-loop heat pumps to be a 15 percent solution by mass of sodium 
chloride in water (i.e., brine). Further, the liquid enthalpy test 
method in Annex C of ISO 13256-1:1998, which is included in the current 
DOE test procedure, requires the use of the specific heat capacity of 
the test liquid for calculating cooling and heating capacity but does 
not specify a value or method for calculating the specific heat 
capacity.
    In the June 2018 RFI, DOE requested comment on whether a standard 
value or calculation method for the specific heat capacity of water 
should be specified in the WSHP test procedure. If a standard value 
should be specified, DOE requested comment on what value should be 
used. 83 FR 29048, 29053 (June 22, 2018).
    In response to DOE's request for comment, AHRI, Trane, and 
WaterFurnace commented that the then draft revision of ISO 13256-1:1998 
included an annex for addressing the specific heat capacity of water 
when using the liquid enthalpy method. These commenters further added 
that antifreeze use is common in WSHPs. They stated that the then-draft 
revision of ISO 13256-1:1998 allows innovation by not prescribing a 
particular antifreeze composition or concentration, but the draft 
standard requires input as to the relevant thermal properties of the 
test fluid for the proper calculation of heat capacity. (Trane, No. 8 
at p. 5; AHRI, No. 12 at pp. 13-14; WaterFurnace, No. 7 at p. 12)
    Section 5.1.7 of ISO 13256-1:2021 requires that the test liquid for 
the low temperature heating test (i.e., EWT of 32 [deg]F) must be a 
brine of the manufacturer's specification, while the test liquid for 
all other tests may be water or a brine of a composition and 
concentration specified by the manufacturer. Contrary to the comments 
received from industry stakeholders about the inclusion of provision 
for specific heat capacity in the then draft revision, ISO 13256-1:2021 
does not specify a value or method for calculating the specific heat 
capacity of any test liquids.
    In response to these considerations and comments, DOE is proposing 
in section 4.1 of proposed appendix C1 that the test liquid for all 
tests other than the proposed optional ``HFL3'' \24\ low temperature 
heating test (i.e., EWT of 32 [deg]F) must be water, unless the 
manufacturer specifies to use a brine of 15-percent solution by mass of 
sodium chloride in water. DOE is proposing in section 4.1 of proposed 
appendix C1 that the test liquid for the optional HFL3 low temperature 
heating test must be a brine of 15-percent solution by mass of sodium 
chloride in water. Ground-loop applications of WSHPs typically use 
brine in the liquid loop, because in cold weather, the liquid 
temperature can reach 32 [deg]F (i.e., the temperature at which water 
freezes) in places. A 15-percent solution by mass of sodium chloride in 
water can withstand temperatures as low as 14 [deg]F before freezing. 
Allowing the use of brine for testing also provides manufacturers the 
flexibility of providing ratings more representative of ground-loop 
applications. Therefore, DOE proposes to require brine as the liquid 
for the optional HFL3 low temperature heating test (conducted with an 
EWT of 32 [deg]F), consistent with section 4.1.9 of ISO 13256-1:1998 
and section 5.1.7 of ISO 13256-1:2021, to avoid the liquid freezing 
during the test.
---------------------------------------------------------------------------

    \24\ ``HFL3'' is the nomenclature used to define the 32 [deg]F 
full load heating test that DOE is proposing to add in Appendix D.
---------------------------------------------------------------------------

    DOE has tentatively concluded that a 15-percent solution by mass of 
sodium chloride, as specified in section 4.1.9.2 of ISO 13256-1:1998, 
is a representative brine composition and concentration for 
applications needing brine (e.g., ground-loop), and that consumers can 
make more representative comparisons between models when all models are 
rated with the same brine composition and concentration.
    As discussed in section III.D.2 of this NOPR, DOE proposes to adopt 
specific sections of AHRI 340/360-2022 in its test procedure for WSHPs. 
AHRI 340/360-2022 in turn references the test method in ANSI/ASHRAE 37-
2009, in which section 12.2.1 requires that thermodynamic properties of 
liquids be obtained from the ASHRAE Handbook--Fundamentals.\25\ The 
ASHRAE Handbook--Fundamentals specifies specific heat capacity values 
for water and for a brine of 15-percent solution by mass of sodium 
chloride at multiple temperatures. The absence of provisions in ISO 
13256-1:1998 for how to determine specific heat capacity for test 
liquids creates the potential for variation in measured values based on 
how specific heat capacity is determined. Therefore, to minimize any 
such variation, DOE is instead proposing to adopt relevant provisions 
of ANSI/ASHRAE 37-2009. DOE has tentatively determined that the 
specifications in ANSI/ASHRAE 37-2009 would be appropriate for testing 
WSHPs because they are the generally accepted industry method used for 
testing similar equipment, such as WCUACs.
---------------------------------------------------------------------------

    \25\ The ASHRAE Handbook--Fundamentals is available at: https://www.ashrae.org/technical-resources/ashrae-handbook.
---------------------------------------------------------------------------

    Issue 17: DOE requests comment on the proposed requirements for 
using water or a brine of 15-percent solution by mass of sodium 
chloride as the test liquid. DOE also requests comment on the 
representativeness and test burden associated with permitting the use 
of different liquids for different tests.
    Issue 18: DOE requests comments on the proposal to utilize the 
thermodynamic properties specified in ANSI/ASHRAE 37-2009 through DOE's 
proposed incorporation by reference of AHRI 340/360-2022.
6. Liquid Flow Rate
a. Full-Load Cooling Tests
    The current DOE test procedure, through adoption of section 4.1.6.2 
of ISO 13256-1:1998, requires units with an integral liquid pump to be 
tested at the liquid flow rates specified by the manufacturer or those 
obtained at zero ESP difference, whichever provides the lower liquid 
flow rate. Section 4.1.6.3 of

[[Page 53330]]

ISO 13256-1:1998 requires that units without an integral liquid pump be 
tested at a liquid flow rate specified by the manufacturer.
    In contrast to the ISO 13256-1:1998 approach, DOE noted in the June 
2018 RFI that AHRI 340/360-2007 does not use a manufacturer-specified 
liquid flow rate, and instead specifies inlet and outlet water 
temperatures for WCUACs to be 85 [deg]F and 95 [deg]F, respectively, 
for standard-rating full-capacity operation. The temperature difference 
between inlet and outlet determines the liquid flow rate for the test. 
83 FR 29048, 29054 (June 22, 2018).
    In the June 2018 RFI, DOE requested comment on how manufacturers 
are selecting water flow rates when testing WSHPs in cases where 
multiple flow rates are provided in product literature. DOE further 
requested comment on what the typical water temperature rise during 
testing is and whether the typical test temperature rise is 
representative of field operation. Id.
    In response to DOE's request for comment, AHRI discussed how the 
AHRI certification program requires a flow rate to be certified, and 
that the flow rate is available on the product certificate and also in 
the supplemental PDF. AHRI stated that certified flow rate makes clear 
which points to use for testing WSHPs, if multiple flow rates are 
provided in the product literature. (AHRI, No. 12 at p. 15) Trane 
commented that only one water flow rate is used to set the rating point 
of each WSHP basic model, and that any other water flow rates provided 
in the catalog literature are simply other application points for 
customers to use. (Trane, No. 8 at p. 5)
    Trane commented that typical values of flow rate and temperature 
rise are 3 gallons per minute (``GPM'') per ton and a 10 [deg]F 
temperature rise in cooling mode. (Trane, No. 8 at p. 5) AHRI and 
WaterFurnace stated that a typical rated water flow rate is 3 GPM/ton 
and field application flow rates are typically 2.25-3 GPM/ton, and that 
this range results in a field temperature rise of 9-14 [deg]F for 
water-loop applications. (AHRI, No. 12 at p. 14; WaterFurnace, No. 7 at 
p. 13)
    Further, AHRI and WaterFurnace stated that the current test 
procedure (which does not specify the outlet water temperature) allows 
the manufacturer to design a more suitable and efficient system by 
having the freedom to innovate systems that perform more efficiently 
with lower pressure drop or perhaps a heat exchanger allowing a high 
flow rate but lower pressure drop. (AHRI, No. 12 at p. 14; 
WaterFurnace, No. 7 at p. 13) AHRI also stated that for PSC pump 
motors,\26\ specifying water flow is more accurate than specifying a 
temperature rise, and that fixing the temperature change would be a 
more difficult approach for these units. (AHRI, No. 12 at p. 14) Trane 
stated that it would be difficult to set a single value of flow rate or 
temperature rise for WSHP testing that would be representative of all 
field applications. (Trane, No. 8 at p. 5) Trane also encouraged DOE to 
not limit the rated water flow rate, indicating that this would 
severely limit the marketplace and be unrepresentative of real-world 
applications. Id. WaterFurnace stated that changing to a constant 
temperature difference approach (i.e., specifying both inlet and outlet 
water temperature) would add undue complication to the certification 
program because the pump power adjustment requires a manufacturer-
specified water flow rate. (WaterFurnace, No. 7 at p. 4)
---------------------------------------------------------------------------

    \26\ A permanent split-capacitor (PSC) motor is a type of 
electric motor that can be used to power water pumps in WSHPs.
---------------------------------------------------------------------------

    Sections 5.1.6.3 and 5.1.6.4 of ISO 13256-1:2021 include provisions 
for setting water flow rate that are equivalent to the provisions in 
sections 4.1.6.2 and 4.1.6.3 of ISO 13256-1:1998. However, DOE is 
concerned that these provisions of ISO 13256-1 have the potential to 
allow manufacturers to specify very high flow rates that may not be 
representative of field operation. An overly high flow rate would 
result in a liquid temperature rise that is lower than what is 
representative of field operating conditions and a liquid heat transfer 
efficiency that is higher than what is representative of field 
operation. In addition, this would result in a measured efficiency that 
is higher than what is representative. Section 4.1.6.2 of ISO 13256-
1:1998 specifies that the flow rate for integral pumps can be no higher 
than the flow rate resulting in zero liquid ESP, but this does not 
ensure that the resulting flow rate is representative of field use. For 
units without integral pumps, ISO 13256-1:1998 has no limits on flow 
rate.
    In consideration of the preceding information and public comments, 
DOE proposes the following. As discussed in section III.D.2 of this 
NOPR, DOE proposes to adopt specific sections of AHRI 340/360-2022 in 
its test procedure for WSHPs, including Table 6. Table 6 of AHRI 340/
360-2022 specifies inlet and outlet liquid temperatures of 85 [deg]F 
and 95 [deg]F, respectively, for standard-rating cooling full-capacity 
operation. This requires that liquid flow rate for the full-load 
cooling test is set at a level that results in a 10 [deg]F temperature 
rise from the 85 [deg]F inlet to the 95 [deg]F outlet temperature.
    DOE notes that Trane commented that a 10 [deg]F temperature rise is 
typical of field operation, and AHRI and WaterFurnace commented that a 
9-14 [deg]F temperature rise is typical. (Trane, No. 8 at p. 5; AHRI, 
No. 12 at p. 14; WaterFurnace, No. 7 at p. 13) These comments indicate 
that the temperature rise specified in Table 6 of AHRI 340/360-2022 is 
representative of field operation. In addition, specifying a fixed 
temperature rise for all WSHPs ensures that all models are tested with 
a temperature rise that is representative of field operating 
conditions. Therefore, DOE has tentatively concluded that testing with 
the required temperature rise specified in Table 6 of AHRI 340/360-2022 
would produce more representative results than allowing manufacturers 
to continue specifying a liquid flow rate.
    Regarding WaterFurnace's comment on the need for a manufacturer-
specified flow rate for the pump power correction, DOE is not proposing 
in section III.F.4 of this NOPR to adopt the pump power correction 
specified in the 1998 and 2021 versions of ISO 13256-1; instead, DOE is 
proposing to include pump power to overcome a representative liquid ESP 
in the calculation of WSHP efficiency (see discussion in section 
III.F.4 of this NOPR). As a result, DOE has tentatively concluded that 
DOE's proposed approach for setting liquid flow rate would not add any 
additional complication to certification.
    Regarding AHRI's and WaterFurnace's comment that the use of 
manufacturer-specified flow rates allows innovation in design, DOE has 
tentatively concluded that setting full-load liquid flow rate based on 
a 10 [deg]F temperature rise would not impede the ability of 
manufacturers to innovate. The requirements of the DOE test procedure 
place no requirements on the design of a WSHP; they only specify 
requirements used to measure the performance of WSHPs in conditions 
that are representative of an average use cycle. As discussed, 
commenters stated that 10 [deg]F is within the range of temperature 
rise values that is representative of water-loop applications. 
Therefore, DOE has tentatively concluded that setting full-load liquid 
flow rate to achieve a 10 [deg]F temperature rise would ensure that all 
WSHPs are tested with a full-load flow rate that is representative of 
an average use cycle.
    For the method of calculating IEER through interpolation and 
extrapolation, DOE is proposing in section 5.1.2 of

[[Page 53331]]

proposed appendix C1 (see section III.E.1.b of this NOPR) to align with 
the provisions in AHRI 340/360-2022, as follows. For the ``CFL3 high 
temperature'' test specified in Table 2 of appendix C1 \27\ for the 
alternative method of calculating IEER, DOE is proposing to specify a 
fixed 10 [deg]F temperature rise, thus specifying 86 [deg]F and 96 
[deg]F, respectively, for the inlet and outlet liquid temperatures. For 
the rest of the full-load tests required in Table 2 of appendix C1 for 
the alternative method of calculating IEER, DOE is proposing that the 
liquid flow rate achieved during the CFL3 full load test be used. This 
proposal for full-load tests is consistent with Table 6 of AHRI 340/
360-2022, because it requires a 10 [deg]F temperature rise from inlet 
to outlet, which is the same amount of temperature rise required for 
full-load testing in Table 6 of AHRI 340/360-2022.
---------------------------------------------------------------------------

    \27\ ``CFL3'' is the nomenclature used in Appendix C1 to define 
a full load cooling test at 86 [deg]F.
---------------------------------------------------------------------------

    Issue 19: DOE requests comment on its proposal to adopt the AHRI 
340/360-2022 approach for setting liquid flow rate for the full-load 
cooling test, namely by specifying inlet and outlet liquid temperature 
conditions rather than using a manufacturer-specified flow rate.
b. Part-Load Cooling Tests
    In this NOPR, DOE is specifying part-load testing as part of the 
IEER test metric (see section III.E.1 of this NOPR), so provisions are 
necessary for determining the liquid flow rate to use during part-load 
tests. Table 9 of AHRI 340/360-2022 specifies use of manufacturer-
specified part-load water flow rates for part-load tests. This is 
similar to the requirements in sections 4.1.6.2 and 4.1.6.3 of ISO 
13256-1:1998 and sections 5.1.6.3 and 5.1.6.4 of ISO 13256-1:2021, 
which specify testing at manufacturer-specified flow rates for all 
tests (see also discussion in section III.F.6.a of this NOPR). 
Therefore, DOE is proposing to incorporate by reference Table 9 of AHRI 
340/360-2022 and also to state in sections 5.1.1 and 5.1.2.1.2 of 
appendix C1 the requirements (from Table 9 of AHRI 340/360-2022) for 
setting part-load liquid flow rate. These requirements apply to both 
IEER determination methods specified in appendix C1 (i.e., Option 1 and 
Option 2).
    Section E7 of AHRI 340/360-2022, which addresses units with 
condenser head pressure control, states that part-load liquid flow rate 
shall not exceed the liquid flow rate used for the full-load tests. 
This requirement is not stated anywhere else in AHRI 340/360-2022, but 
DOE has tentatively concluded that it provides a valuable control on 
the upper limit of liquid flow rates for part-load tests. As a result, 
DOE is proposing in sections 5.1.1 and 5.1.2.1.2 of appendix C1 that 
this requirement apply to all part-load tests for WSHPs.
    AHRI 340/360-2022 does not specify the liquid flow rate to use when 
the unit is operating at part load should the manufacturer not provide 
one. Therefore, DOE is proposing in sections 5.1.1 and 5.1.2.1.2 of 
appendix C1 to use the liquid flow rate from full-load testing if the 
manufacturer does not specify a part-load liquid flow rate.
    Issue 20: DOE requests feedback on its proposals to use 
manufacturer-specified part-load liquid flow rates for part-load tests, 
that the part-load flow rate be no higher than the full-load flow rate, 
and to use the full-load liquid flow rate if no part-load liquid flow 
rate is specified.
c. Heating Tests
    Consistent with the proposal in section III.F.6.a of this NOPR for 
a method of determining full-load cooling liquid flow rate of WSHPs 
based on outlet water temperature, rather than using a manufacturer-
specified flow rate as specified by the current Federal test procedure, 
DOE is proposing provisions for setting liquid flow rate during heating 
tests. More specifically, DOE is proposing that the liquid flow rate 
determined from the full-load cooling test be used for all heating 
tests. DOE has tentatively concluded that full-load heating flow rates 
would generally be the same as full-load cooling flow rates for WSHPs 
installed in field applications, as the compressor(s) would be 
operating at full load in both cases. Therefore, DOE has tentatively 
concluded that the liquid flow rate used for the full-load cooling test 
is a representative flow rate to use for heating tests.
    Specifically, DOE is proposing to specify in section 6.1 of 
proposed appendix C1 that if IEER is determined using option 1 in 
section 5.1 of proposed appendix C1, the liquid flow rate determined 
from the ``Standard Rating Conditions Cooling'' test for water-cooled 
equipment, as defined in Table 6 of AHRI 340/360-2022, must be used for 
all heating tests. If IEER is determined using option 2 in section 5.1 
of proposed appendix C1, DOE is proposing in section 5.1.2.1.1 of 
proposed appendix C1 to use the liquid flow rate determined from the 
CFL3 high temperature cooling test for all heating tests.
    Issue 21: DOE requests comment on its proposal to use the liquid 
flow rate determined from the full-load cooling test for all heating 
tests.
d. Condition Tolerance
    Table 9 of ISO 13256-1:1998 and Table 11 of ISO 13256-1:2021 both 
include an operating tolerance of 2 percent and a condition tolerance 
of 1 percent for the liquid flow rate of WSHPs.
    As discussed in section III.D.2 of this NOPR, DOE proposes to adopt 
specific sections of AHRI 340/360-2022 in its test procedure for WSHPs. 
AHRI 340/360-2022 in turn references the test method in ANSI/ASHRAE 37-
2009. Table 11 of AHRI 340/360-2022 includes an operating tolerance of 
2 percent for liquid flow rate, but neither AHRI 340/360-2022 nor ANSI/
ASHRAE 37-2009 include a condition tolerance on liquid flow rate.
    It is DOE's understanding that a condition tolerance is needed for 
all tests with a target liquid flow rate. As discussed in sections 
III.F.6.a through III.F.6.c of this NOPR, DOE is proposing that the 
full-load cooling test (if using option 1 for determining IEER, the 
``standard rating conditions cooling'' test in Table 5 of AHRI 340/360-
2022; if using option 2 for determining IEER, the ``CFL3 high 
temperature'' test in Table 2 of appendix C1) would be conducted with a 
liquid flow rate determined via a specified temperature rise rather 
than via a target liquid flow rate, while other cooling tests and all 
heating tests would have target liquid flow rates (manufacturer-
specified for part-load cooling tests, and a target flow rate the same 
as the flow rate determined from the full-load cooling test for all 
other cooling and heating tests). Therefore, DOE is proposing a liquid 
flow rate condition tolerance that applies for all tests with target 
liquid flow rates (i.e., excluding the tests conducted with a specified 
temperature rise--the ``standard rating conditions cooling'' test in 
Table 5 of AHRI 340/360-2022 and the ``CFL3 high temperature'' test in 
Table 2 of appendix C1).
    Specifically, DOE is proposing to require in sections 5.1.1, 
5.1.2.1.2, and 6.1 of appendix C1 a condition tolerance of 1 percent 
for liquid flow rate, consistent with the condition tolerance specified 
in Table 9 of ISO 13256-1:1998. This requirement is in addition to 
DOE's proposed adoption of Table 11 of AHRI 340/360-2022, which 
specifies an operating tolerance of 2 percent for liquid flow rate.
    Issue 22: DOE requests comment on its proposal to specify an 
operating tolerance of 2 percent and a condition tolerance of 1 percent 
for liquid flow

[[Page 53332]]

rate in all tests with a target liquid flow rate.
7. Refrigerant Line Losses
    Split-system WSHPs have refrigerant lines that can transfer heat to 
and from their surroundings, which can incrementally affect measured 
capacity. To account for this transfer of heat (referred to as ``line 
losses''), the current DOE test procedure, through adoption of ISO 
13256-1:1998, provides that if line loss corrections are to be made, 
they shall be included in the capacity calculations (in section B4.2 
for the indoor air enthalpy method and in section C3.3 for the liquid 
enthalpy test method of ISO 13256-1:1998). ISO 13256-1:1998 does not 
specify the circumstances that require line loss corrections nor the 
method to use to determine an appropriate correction.
    Section 7.3.3.4 of ANSI/ASHRAE 37-2009, the method of test 
referenced in AHRI 340/360-2022, specifies more detailed provisions to 
account for line losses of split systems in the outdoor air enthalpy 
method, and section 7.6.7.1 of ANSI/ASHRAE 37-2009 specifies to use the 
same provisions for the outdoor liquid coil method.
    In the June 2018 RFI, DOE requested comment on whether the 
provisions for line losses in ANSI/ASHRAE 37-2009 would be appropriate 
for testing WSHPs. Furthermore, DOE requested comment on what 
modifications to ISO 13256-1:1998 might be necessary to further address 
line losses and how manufacturers of split-system WSHPs currently 
incorporate line loss adjustments into both heating and cooling 
capacity calculations. 83 FR 29048, 29052-29053 (June 22, 2018).
    In commenting on DOE's June 2018 RFI, AHRI, Trane, and WaterFurnace 
stated that refrigerant line losses would not be a relevant issue 
because there are very few, if any, split-system WSHPs in the 
commercial market. (AHRI, No. 12 at p. 13; Trane, No. 8 at p. 5; 
WaterFurnace, No. 7 at pp. 11-12)
    Section E.3.3 of ISO 13256-1:2021 contains the same statement about 
line loss correction as sections B4.2 and C3.3 in ISO 13256-1:1998. 
Thus, ISO 13256-1:2021 contains no additional provisions regarding line 
loss corrections.
    As stated previously, DOE has identified a number of split-system 
WSHPs, several of which are certified in the DOE Compliance 
Certification Database, and the Federal test procedure \28\ applies to 
any WSHP that meets DOE's definition of a WSHP. Further, because split-
system WSHPs are available on the market, test procedure provisions are 
needed for testing them, regardless of their share of the WSHP market.
---------------------------------------------------------------------------

    \28\ Currently, the DOE test procedure applies to all WSHPs with 
a cooling capacity less than 135,000 Btu/h. However, DOE is 
proposing in section III.A of this NOPR to increase the scope of the 
Federal test procedure to include all WSHPs with a cooling capacity 
less than 760,000 Btu/h.
---------------------------------------------------------------------------

    As discussed in section III.D.2 of this NOPR, DOE proposes to adopt 
specific sections of AHRI 340/360-2022 in its test procedure for WSHPs. 
AHRI 340/360-2022 in turn references the test method in ANSI/ASHRAE 37-
2009. As described earlier in this section, section 7.6.7.1 of ANSI/
ASHRAE 37-2009 specifies to use the provisions in section 7.3.3.4 of 
ANSI/ASHRAE 37-2009 for making line loss adjustments when using the 
outdoor liquid coil method. Section 7.3.3.4 of ANSI/ASHRAE 37-2009 
specifies calculations for determining the line losses for bare copper 
or insulated lines. The absence of provisions in ISO 13256-1:1998 for 
how to determine refrigerant line losses creates the potential for 
variation in measured values based on how line losses are determined. 
To minimize any such variation, DOE is proposing to adopt the relevant 
provisions in ANSI/ASHRAE 37-2009. DOE has tentatively determined that 
the specifications in ANSI/ASHRAE 37-2009 would be appropriate for 
testing WSHPs because they are the generally accepted industry method 
used for testing similar equipment, such as WCUACs.
    Issue 23: DOE requests comments on the proposal to adopt the 
provisions for line loss adjustments included in sections 7.6.7.1 and 
7.3.3.4 of ANSI/ASHRAE 37-2009 through incorporation by reference of 
AHRI 340/360-2022.
8. Airflow Measurement
    The current DOE WSHP test procedure, through adoption of section 
D.1 of ISO 13256-1:1998, requires airflow measurements to be made in 
accordance with the provisions specified in several different industry 
test standards, ``as appropriate.'' \29\ However, ISO 13256-1:1998 is 
not explicit regarding the circumstances under which the different 
airflow measurement approaches included in these industry test 
standards should be used.
---------------------------------------------------------------------------

    \29\ The cited industry test standards include: ISO 3966:1977, 
``Measurement of fluid flow in closed conduits--Velocity area method 
using Pitot static tubes;'' ISO 5167-1:1991, ``Measurement of fluid 
flow by means of pressure differential devices--Part 1: Orifice 
plates, nozzles and Venturi tubes inserted in circular cross-section 
conduits running full;'' and ISO 5221:1984, ``Air Distribution and 
air diffusion--Rules to methods of measuring airflow rate in an air 
handling duct.'' These standards can be purchased from the ISO store 
at https://www.iso.org/store.html.
---------------------------------------------------------------------------

    Section F8 of ISO 13256-1:1998 specifies the requirements for the 
nozzle apparatus used to measure airflow. This device determines 
airflow by measuring the change in pressure across a nozzle of known 
geometry. Airflow derivations using this approach often include a 
discharge coefficient (i.e., the ratio of actual discharge air to 
theoretical discharge air) to account for factors that reduce the 
actual discharge air, such as nozzle resistance and airflow turbulence. 
In general, as the nozzle throat diameter decreases, nozzle resistance 
increases, thereby reducing actual discharge which is characterized by 
a lower discharge coefficient. Turbulent airflow (as characterized by 
Reynolds numbers \30\) and temperature also impact the discharge 
coefficient.
---------------------------------------------------------------------------

    \30\ ``Reynolds number'' is a dimensionless number that 
characterizes the flow properties of a fluid. Section F8.9 of ISO 
13256-1:1998 includes an equation for calculating Reynolds number 
that depends on a temperature factor, air velocity, and throat 
diameter.
---------------------------------------------------------------------------

    Section F8.9 of ISO 13256-1:1998 specifies that it is preferable to 
calibrate the nozzles in the nozzle apparatus, but that nozzles of a 
specific geometry may be used without calibration and by using the 
appropriate discharge coefficient specified in a lookup table in 
section F8.9 of ISO 13256-1:1998. ISO 13256-1:1998 does not specify the 
method that should be applied, however, to determine the coefficient of 
discharge for conditions that do not exactly match the values provided 
in the look-up table.
    Elsewhere, sections 6.2 and 6.3 of ANSI/ASHRAE 37-2009 includes 
provisions regarding the nozzle airflow measuring apparatus that are 
identical to the provisions in section F8 of ISO 13256-1:1998, except 
for the method used to determine the coefficient of discharge. Section 
6.3.3 of ANSI/ASHRAE 37-2009 uses a calculation in place of the look-up 
table used in ISO 13256-1:1998, thereby allowing determination of the 
coefficient of discharge at any point within the specified range.
    In the June 2018 RFI, DOE requested comment on which of the methods 
specified in ISO 13256-1:1998 (i.e., ISO 3966:1977, ISO 5167-1:1991, 
and ISO 5221:1984) are used by manufacturers to measure airflow of 
WSHPs, and whether this varies based on WSHP capacity or configuration. 
83 FR 29048, 29054 (June 22, 2018). DOE further requested information 
on how manufacturers determine the coefficient of discharge for air 
temperatures and Reynolds numbers that fall between the values

[[Page 53333]]

specified in the look-up table in section F8.9 Annex F to ISO 13256-
1:1998. Id. DOE also requested comment on whether it should incorporate 
by reference additional industry test standards that specify the 
calculation method for airflow, such as ANSI/ASHRAE 37-2009. Id.
    On this topic, AHRI, Trane, and WaterFurnace commented that 
manufacturers generally calibrate each nozzle to determine the 
coefficient of discharge, consistent with the ISO 13256-1:1998 
conditions. These commenters also stated that most manufacturers use 
air tunnels for airside measurements based upon ANSI/ASHRAE 37-2009 and 
ANSI/AMCA Standard 210-16, Laboratory Methods of Testing Fans for 
Certified Aerodynamic Performance Rating (``ANSI/AMCA 210''),\31\ and 
that these tunnels generally satisfy the requirements of ISO 5221, ISO 
3966, and ISO 5167. Furthermore, these commenters stated that the draft 
revision of ISO 13256-1:1998 enhanced the method of test annexes, as 
ISO standards cannot reference national standards. (Trane, No. 8 at p. 
5; AHRI, No. 12 at pp. 3, 14; WaterFurnace, No. 7 at p. 12)
---------------------------------------------------------------------------

    \31\ ANSI/AMCA 210-16 is available at: https://www.amca.org/assets/resources/public/pdf/Education%20Modules/AMCA%20210-16.pdf.
---------------------------------------------------------------------------

    To the point raised by commenters, Annex B of ISO 13256-1:2021 
specifies requirements for airflow measurement and nozzle apparatus 
that are consistent with the requirements in section F8 of ISO 13256-
1:1998, and section B.3.5.3 of ISO 13256-1:2021 contains equations for 
determining discharge coefficients that are equivalent to the equations 
in section 6.3.3 of ANSI/ASHRAE 37-2009.
    As discussed in section III.D.2 of this NOPR, DOE proposes to adopt 
specific sections of AHRI 340/360-2022 in its test procedure for WSHPs. 
AHRI 340/360-2022 in turn references the test method in ANSI/ASHRAE 37-
2009. As stated earlier in this section, the provisions of ANSI/ASHRAE 
37-2009 provide more specificity in the determination of airflow 
characteristics than the provisions of ISO 13256-1:1998, but they 
otherwise align with the corresponding provisions in ISO 13256-1:1998. 
The provisions of ANSI/ASHRAE 37-2009 are also equivalent to those in 
ISO 13256-1:2021. In addition, as commenters stated, air measurement 
apparatuses based upon ANSI/ASHRAE 37-2009 satisfy the requirements of 
ISO 13256-1:1998. Therefore, DOE has tentatively concluded that the 
proposed test procedure would provide a representative and repeatable 
method for measuring airflow.
    Issue 24: DOE requests comments on the proposal to adopt the 
calculation of discharge coefficients and air measurement apparatus 
requirements of ANSI/ASHRAE 37-2009.
9. Air Condition Measurements
    Indoor air temperature and humidity are key parameters that affect 
WSHP performance, and for this reason, ISO 13256-1:1998 requires 
accurate indoor air condition measurements. However, informative 
annexes E and F of ISO 13256-1:1998 specify few requirements for the 
methods used to measure indoor air temperature and humidity.
    In the June 2018 RFI, DOE identified that Appendix C of AHRI 340/
360-2015 (the most current version of AHRI 340/360 at the time) 
provides details on entering outdoor air temperature measurement for 
air-cooled and evaporatively-cooled CUACs, including air sampling tree 
and aspirating psychrometer requirements, but that AHRI 340/360-2015 
does not state that these provisions apply for measurement of entering 
indoor air temperature and leaving indoor air temperature. 83 FR 29048, 
29054 (June 22, 2018). DOE requested comment on whether the 
requirements for outdoor entering air measurements in Appendix C of 
AHRI 340/360-2015 (excluding the temperature uniformity requirements in 
Table C2), such as air sampling requirements and aspirating 
psychrometer requirements, would be appropriate for measurement of 
indoor air entering and leaving temperatures for WSHPs. Id.
    On this topic, Trane, AHRI, and WaterFurnace commented that the ISO 
working group agreed on revised method of test annexes with further 
provisions for air sampling, based off provisions in ASHRAE 37; ASHRAE 
41.1, Standard Methods for Temperature Measurement; ASHRAE 41.2, 
Standard Methods for Air Velocity and Airflow Measurement; and ASHRAE 
41.3, Standard Methods for Pressure Measurement.\32\ (Trane, No. 8 at 
p. 5; AHRI, No. 12 at p. 15; WaterFurnace, No. 7 at p. 13)
---------------------------------------------------------------------------

    \32\ All ASHRAE standards can be found at: https://webstore.ansi.org/sdo/ashrae.
---------------------------------------------------------------------------

    After its subsequent publication, DOE reviewed ISO 13256-1:2021, 
but in contrast to the commenters' expressed expectations, the 
Department found that the updated ISO standard specifies no 
requirements for the methods used to measure indoor air temperature and 
humidity, including no provisions for air sampling and aspirating 
psychrometers.
    As discussed in section III.D.2 of this NOPR, DOE proposes to adopt 
specific sections of AHRI 340/360-2022 in its test procedure for WSHPs. 
Appendix C of AHRI 340/360-2022 provides more detailed specifications 
for the measurement of air conditions (including indoor air) than ISO 
13256-1:1998, including aspirating psychrometer requirements in section 
C3.2.1 of AHRI 340/360-2022 and sampling requirements in section C3.3 
of AHRI 340/360-2022. The absence of provisions in ISO 13256-1:1998 for 
how indoor air condition measurements are conducted creates the 
potential for variation in measured values based on how indoor air 
condition measurements are taken. To minimize any such variation, DOE 
is proposing to specify the measurement provisions in Appendix C of 
AHRI 340/360-2022. DOE has tentatively determined that the 
specifications in AHRI 340/360-2022 would be appropriate for testing 
WSHPs because they are the generally accepted industry method used for 
testing similar equipment, such as WCUACs.
    Issue 25: DOE requests comments on the proposal to adopt the air 
condition measurement provisions in Appendix C of AHRI 340/360-2022.
10. Duct Losses
    In the calculations for cooling and heating capacities for the 
indoor air enthalpy test method of ISO 13256-1:1998, the test standard 
includes a footnote in sections B3 and B4 of annex B stating that the 
equations do not provide allowances for heat leakage in the test 
equipment (i.e., duct losses). In contrast, section 7.3.3.3 of ANSI/
ASHRAE 37-2009 requires adjustments for such heat leakages and 
specifies methods to calculate appropriate values for the adjustments.
    In the June 2018 RFI, DOE requested comment on whether the duct 
loss adjustments as described in section 7.3.3.3 of ANSI/ASHRAE 37-2009 
or any other duct loss adjustments are used to adjust capacity measured 
using the indoor air enthalpy method when testing WSHPs. 83 FR 29048, 
29054 (June 22, 2018).
    In response to DOE's request for comment, AHRI, WaterFurnace, and 
Trane commented that manufacturers typically adjust capacity for duct 
losses consistent with ANSI/ASHRAE 37-2009, and that these provisions 
are being included in the revised version of ISO 13256-1:1998. (AHRI, 
No. 12 at p. 14; WaterFurnace, No. 7 at pp. 12-13; Trane, No. 8 at p. 
5)

[[Page 53334]]

    Despite commenters' expressed expectations, DOE notes that similar 
to ISO 13256-1:1998, ISO 13256-1:2021 does not address duct losses. 
Specifically, section C.4 of ISO 13256-1:2021 includes a note that 
states that the formulas for calculating cooling and heating capacity 
in sections C.3 and C.4 do not provide allowance for heat leakage in 
the test duct and the discharge chamber. Further, ISO 13256-1:2021 does 
not specify a method for calculating the duct losses.
    As discussed in section III.D.2 of this NOPR, DOE proposes to adopt 
specific sections of AHRI 340/360-2022 in its test procedure for WSHPs. 
AHRI 340/360-2022 in turn references the test method in ANSI/ASHRAE 37-
2009. As discussed earlier in this section, section 7.3.3.3 of ANSI/
ASHRAE 37-2009 requires, and provides equations for, duct loss 
adjustments. The absence of provisions in ISO 13256-1:1998 for how to 
determine duct losses creates the potential for variation in measured 
values based on how and whether duct losses are accounted for. To 
minimize any such variation, DOE is proposing to adopt the provisions 
in ANSI/ASHRAE 37-2009. DOE has tentatively determined that the 
specifications in ANSI/ASHRAE 37-2009 would be appropriate for testing 
WSHPs because they are the generally accepted industry method used for 
testing similar equipment, such as WCUACs.
    Issue 26: DOE requests comments on the proposal to adopt the duct 
loss provisions in section 7.3.3.3 of ASHRAE 37-2009.
11. Refrigerant Charging
    The amount of refrigerant can have a significant impact on the 
system performance of air conditioners and heat pumps. DOE's current 
test procedure for WSHPs requires that units be set up for test in 
accordance with the manufacturer installation and operation manuals. 10 
CFR 431.96(e). In addition, the current DOE test procedure states that 
if the manufacturer specifies a range of superheat, sub-cooling, and/or 
refrigerant pressures in the installation and operation manual, any 
value within that range may be used to determine refrigerant charge or 
mass of refrigerant, unless the manufacturer clearly specifies a rating 
value in its installation or operation manual, in which case the 
specified rating value shall be used. Id. However, the current DOE test 
procedure does not provide charging instructions to be used if the 
manufacturer does not provide instructions in the manual that is 
shipped with the unit or if the provided instructions are unclear or 
incomplete. In addition, ISO 13256-1:1998 does not provide any specific 
guidance on setting and verifying the refrigerant charge of a unit 
aside from stating in section A2.3 of that standard that equipment 
shall be evacuated and charged with the type and amount of refrigerant 
specified in the manufacturer's instructions, where necessary.
    DOE noted in the June 2018 RFI that the test procedure final rule 
for CAC/HPs published in the Federal Register on June 8, 2016 (81 FR 
36992, ``June 2016 CAC TP final rule'') established a comprehensive 
approach for refrigerant charging to improve test reproducibility. 83 
FR 29048, 29054 (June 22, 2018). The approach specifies which set of 
installation instructions to use for charging, explains what to do if 
no instructions are provided, specifies that target values of 
parameters are the centers of the ranges allowed by installation 
instructions, and specifies tolerances for the measured values. See 10 
CFR part 430, subpart B, appendix M, section 2.2.5. The approach also 
requires that refrigerant line pressure gauges be installed for single-
package units, unless otherwise specified in manufacturer instructions. 
Id. As part of the June 2018 RFI, DOE sought comment on whether it 
would be appropriate to adopt an approach for charging requirements for 
WSHPs similar to the approach adopted in the June 2016 CAC TP final 
rule. 83 FR 29048, 29055 (June 22, 2018).
    The CA IOUs commented that only about 10 percent of WSHPs are split 
systems, and that many of the charging requirements in the June 2016 
CAC TP final rule are for split systems and do not apply to single-
package units. However, the CA IOUs went on to state that adopting 
provisions from the June 2016 CAC TP final rule would be useful for 
single-package units, specifically aspects that relate to pressure 
gauges for package units and banning charge adjustment during testing. 
The CA IOUs also suggested that DOE should develop language to address 
equipment that arrives at the test laboratory with damage, possibly 
giving some allowance to recharge WSHPs with minor damage but requiring 
a new unit to be shipped in the case of major damage. The CA IOUs 
further stated that adopting provisions similar to the June 2016 CAC TP 
final rule would be beneficial for the minority of WSHPs that require 
charging in the laboratory. (CA IOUs, No. 9 at p. 2)
    Trane commented that all of its WSHP offerings are single-package 
units that are charged at the factory, so charging requirements would 
not be necessary. Trane added that packaged equipment requires no 
external refrigerant lines, and, therefore, superheat and subcooling do 
not need to be considered. (Trane, No. 8 at p. 6) WaterFurnace stated 
that split-system WSHPs are not sold for commercial applications, and, 
therefore, commercial WSHPs are not field-charged. (WaterFurnace, No. 7 
at p. 14) AHRI and Trane commented that adopting charging requirements 
would not be appropriate, because many WSHPs have no service ports, and 
that units that do have service ports are charged by weight to the 
specification on the nameplate. (AHRI, No. 12 at p. 15; Trane, No. 8 at 
p. 6)
    DOE notes that the subsequently published ISO 13256-1:2021 does not 
include any provisions regarding refrigerant charging that differ from 
ISO 13256-1:1998; the provisions in section A.2.4 of ISO 13256-1:2021 
align with section A2.3 of ISO 13256-1:1998.
    As discussed in section III.D.2 of this NOPR, DOE proposes to adopt 
specific sections of AHRI 340/360-2022 in its test procedure for WSHPs, 
including section 5.8. Section 5.8 of AHRI 340/360-2022 specifies a 
comprehensive set of provisions regarding refrigerant charging that is 
similar to the approach adopted in the June 2016 CAC TP final rule. 81 
FR 36992, 37030-37031 (June 8, 2016). DOE has tentatively concluded 
that these provisions provide sufficient guidance for setting and 
verifying the refrigerant charge of a WSHP. Section 5.8 requires that 
units be charged at conditions specified by the manufacturer in 
accordance with the manufacturer installation instructions or labels 
applied to the unit. If no manufacturer-specified charging conditions 
are provided, section 5.8 specifies charging at the standard rating 
conditions (as defined in Table 6 of AHRI 340/360-2022). Section 5.8 
also provides additional charging instructions to be used if the 
manufacturer does not provide instructions or if the provided 
instructions are unclear or incomplete (e.g., specifying default 
charging targets to use if none are provided by the manufacturer, 
specifying an instruction priority to be used in the event of 
conflicting information between multiple manufacturer-provided charging 
instructions).
    DOE disagrees with the commenters' assertions that charging 
requirements are not appropriate for WSHPs. While DOE acknowledges that 
most WSHP models are single-package units, the Department tentatively 
concludes that charging provisions are warranted for single-package 
units. DOE notes that AHRI 210/240-2023 (in section 5.1.8),

[[Page 53335]]

AHRI 340/360-2022 (in section 5.8), and AHRI 390-2021 (in section 
5.6.3) include charging provisions that apply to single-package units. 
Additionally, as stated previously, DOE has identified a number of 
split-system WSHPs, several of which are certified in the DOE 
Compliance Certification Database, and the Federal test procedure \33\ 
applies to any WSHP that meets DOE's definition of a WSHP. Further, 
because split-system WSHPs exist, test procedure provisions are needed 
for testing them, regardless of their share of the WSHP market.
---------------------------------------------------------------------------

    \33\ Currently, the DOE test procedure applies to all WSHPs with 
a cooling capacity less than 135,000 Btu/h. However, DOE is 
proposing in section III.A of this NOPR to increase the scope of the 
Federal test procedure to include all WSHPs with a capacity less 
than 760,000 Btu/h.
---------------------------------------------------------------------------

    Further, while the use of pressure gauges is not necessary to 
adjust charge if charging is based only on parameters such as charge 
weight that do not require measurement of refrigerant pressure, 
installation of pressure gauges would be warranted for charge 
adjustment if charging is based on parameters that require measurement 
of refrigerant pressure such as subcooling or superheat. Additionally, 
DOE has identified several WSHP service manuals that allow for charge 
adjustment in the field, indicate the presence of pressure ports, and 
provide guidance for confirmation of charge based on sub-cooling or 
superheat.
    Therefore, DOE has tentatively concluded that the provisions 
regarding refrigerant charging in section 5.8 of AHRI 340/360-2022, 
including the provisions specific to installation of pressure gauges 
for single-package units in section 5.8.4 of AHRI 340/360-2022, are 
warranted for testing WSHPs. DOE has tentatively determined that these 
provisions ensure that WSHPs are set up for testing with refrigerant 
charging instructions that are representative of field installations, 
and that testing is conducted in a repeatable manner. DOE also notes 
that the refrigerant charging provisions in AHRI 340/360-2022 are 
generally consistent with the industry consensus test procedures for 
testing several categories of air conditioning and heating equipment 
(e.g., AHRI 340/360 for CUAC/HPs, AHRI 210/240-2023 for CAC/HPs, AHRI 
1230-2021 for VRF multi-split systems, AHRI 390 for SPVUs), and DOE has 
tentatively concluded that there is no aspect of WSHPs that differs 
from all other types of air conditioners and heat pumps that would 
indicate such provisions are not needed.
    Issue 27: DOE requests comments on the proposal to adopt the 
refrigerant charging requirements in section 5.8 of AHRI 340/360-2022.
12. Voltage
    Operating voltage can affect the measured efficiency of air 
conditioners. The current DOE WSHP test procedure, through adoption of 
Tables 1 and 2 of ISO 13256-1:1998, requires units rated with dual 
nameplate voltages to be tested at both voltages or at the lower 
voltage if only a single rating is to be published.
    In the June 2018 RFI, DOE requested data and information on the 
extent of the effect that voltage has on air conditioning equipment and 
if there is a consistent relationship between voltage and efficiency. 
DOE also requested comment on whether certain voltages within common 
dual nameplate voltages (e.g., 208/230 V) are more representative of 
typical field conditions. 83 FR 29048, 29055 (June 22, 2018).
    On this topic, Trane commented that performance varies slightly 
with voltage, and that to be conservative, Trane tests its units at 
multiple voltages and rates at the lowest measured efficiency. (Trane, 
No. 8 at p. 6) AHRI and WaterFurnace had a somewhat different 
viewpoint, commenting that performance at each voltage is not normally 
measured and that the effect of voltage varies by compressor line 
(e.g., stating that in the most recent generation Copeland Scroll 
product, the 208V model is 1-2 percent less efficient than the 
corresponding 230V model). AHRI and WaterFurnace also stated that there 
are several voltage options available commercially, and that voltage 
selection depends on several different aspects of the installed 
application. (AHRI, No. 12 at pp. 15-16; WaterFurnace, No. 7 at p. 14)
    DOE notes that tables 2 and 3 of ISO 13256-1:2021 specify the same 
voltage requirements for testing units rated with dual nameplate 
voltages as tables 1 and 2 of ISO 13256-1:1998.
    As discussed in section III.D.2 of this NOPR, DOE proposes to adopt 
specific sections of AHRI 340/360-2022 in its test procedure for WSHPs, 
including section 6.1.3.1. Section 6.1.3.1 of AHRI 340/360-2022 
specifies that units with dual nameplate voltage ratings must be tested 
at the lower of the two voltages if only a single standard rating is to 
be published, or at both voltages if two standard ratings are to be 
published. This approach is equivalent to the approach for dual 
nameplate voltages specified in tables 1 and 2 of ISO 13256-1:1998 and 
tables 2 and 3 of ISO 13256-1:2021.
    Issue 28: DOE requests comments on the proposal to adopt the 
voltage provisions in section 6.1.3.1 of AHRI 340/360-2022.

G. Configuration of Unit Under Test

1. Summary
    WSHPs are sold with a wide variety of components, including many 
that can optionally be installed on or within the unit both in the 
factory and in the field. The following sections address the required 
configuration of units under test. In all cases, these components are 
distributed in commerce with the WSHP but can be packaged or shipped in 
different ways from the point of manufacturer for ease of 
transportation. Each optional component may or may not affect a model's 
measured efficiency when tested to the DOE test procedure proposed in 
this NOPR. For certain components not directly addressed in the DOE 
test procedure, this NOPR proposes more specific instructions on how 
each component should be handled for the purposes of making 
representations in 10 CFR part 429. Specifically, these proposed 
instructions would provide manufacturers clarity on how components 
should be treated and how to group individual models with and without 
optional components for the purposes of representations to reduce 
burden. DOE is proposing these provisions in 10 CFR part 429 to allow 
for testing of certain individual models that can be used as a proxy to 
represent the performance of equipment with multiple combinations of 
components.
    DOE is proposing to handle WSHP components in two distinct ways in 
this NOPR to help manufacturers better understand their options for 
developing representations for their differing product offerings. 
First, DOE proposes that the treatment of certain components is 
specified by the test procedure, such that their impact on measured 
efficiency is limited. For example, a fresh air damper must be set in 
the closed position and sealed during testing, resulting in a measured 
efficiency that would be similar or identical to the measured 
efficiency for a unit without a fresh air damper. Second, DOE is 
proposing provisions expressly allowing certain models to be grouped 
together for the purposes of making representations and allowing the 
performance of a model without certain optional components to be used 
as a proxy for models with any combinations of the specified 
components, even if such components would impact the measured 
efficiency of a model. A steam/hydronic coil is an example of

[[Page 53336]]

such a component. The efficiency representation for a model with a 
steam/hydronic coil is based on the measured performance of the WSHP as 
tested without the component installed because the steam/hydronic coil 
is not easily removed from the WSHP for testing.\34\
---------------------------------------------------------------------------

    \34\ Note that in certain cases, as explained further in section 
III.G.3.b of this document, the representation may have to be based 
on an individual model with a steam/hydronic coil.
---------------------------------------------------------------------------

2. Background
    In 2013, the Appliance Standards and Rulemaking Federal Advisory 
Committee formed the Commercial HVAC Working Group to engage in a 
negotiated rulemaking effort regarding the certification of certain 
commercial heating, ventilating, and air conditioning equipment, 
including WSHPs. (See 78 FR 15653 (March 12, 2013)) This Commercial 
HVAC Working Group submitted a term sheet (``Commercial HVAC Term 
Sheet'') providing the Commercial HVAC Working Group's recommendations. 
(Docket No. EERE-2013-BT-NOC-0023, No. 52) \35\ The Commercial HVAC 
Working Group recommended that DOE issue guidance under current 
regulations on how to test certain equipment features when included in 
a basic model, until such time as the testing of such features can be 
addressed through a test procedure rulemaking. The Commercial HVAC Term 
Sheet listed the subject features under the heading ``Equipment 
Features Requiring Test Procedure Action.'' (Id at pp. 3-9) The 
Commercial HVAC Working Group also recommended that DOE issue an 
enforcement policy stating that DOE would exclude certain equipment 
with specified features from Departmental testing, but only when the 
manufacturer offers for sale at all times a model that is identical in 
all other features; otherwise, the model with that feature would be 
eligible for Departmental testing. These features were listed under the 
heading ``Equipment Features Subject to Enforcement Policy.'' (Id. at 
pp. 9-15)
---------------------------------------------------------------------------

    \35\ Available at www.regulations.gov/document/EERE-2013-BT-NOC-0023-0052.
---------------------------------------------------------------------------

    On January 30, 2015, DOE issued a Commercial HVAC Enforcement 
Policy addressing the treatment of specific features during 
Departmental testing of commercial HVAC equipment. (See www.energy.gov/gc/downloads/commercial-equipment-testing-enforcement-policies) The 
Commercial HVAC Enforcement Policy stated that--for the purposes of 
assessment testing pursuant to 10 CFR 429.104, verification testing 
pursuant to 10 CFR 429.70(c)(5), and enforcement testing pursuant to 10 
CFR 429.110--DOE would not test a unit with one of the optional 
features listed for a specified equipment type if a manufacturer 
distributes in commerce an otherwise identical unit that does not 
include one of the optional features. (Id at p. 1) The objective of the 
Commercial HVAC Enforcement Policy is to ensure that each basic model 
has a commercially available version eligible for DOE testing. That is, 
each basic model includes a model either without the optional 
feature(s) listed in the policy or that is eligible for testing with 
the feature(s). Id. The features in the Commercial HVAC Enforcement 
Policy for WSHPs (Id at pp. 1-3 and 5-6) align with the Commercial HVAC 
Term Sheet's list designated ``Equipment Features Subject to 
Enforcement Policy.''
    By way of comparison, AHRI 340/360-2022 includes Appendix D, ``Unit 
Configuration for Standard Efficiency Determination--Normative.'' 
Section D3 of AHRI 340/360-2022 includes a list of features that are 
optional for testing, and it further specifies the following general 
provisions regarding testing of units with optional features:
     If an otherwise identical model (within the basic model) 
without the feature is not distributed in commerce, conduct tests with 
the feature according to the individual provisions specified in section 
D3 of AHRI 340/360-2022.
     For each optional feature, section D3 of AHRI 340/360-2022 
includes explicit instructions on how to conduct testing for equipment 
with the optional feature present.
    The optional features provisions in AHRI 340/360-2022 are generally 
consistent with DOE's Commercial HVAC Enforcement Policy, but the 
optional features in section D3 of AHRI 340/360-2022 do not entirely 
align with the list of features included for WSHPs in the Commercial 
HVAC Enforcement Policy.
    DOE notes that the list of features and provisions in section D3 of 
Appendix D of AHRI 340/360-2022 conflates components that can be 
addressed by testing provisions with components that if present on a 
unit under test, could have a substantive impact on test results and 
that cannot be disabled or otherwise mitigated. This differentiation 
was central to the Commercial HVAC Term Sheet, which as noted 
previously, included separate lists for ``Equipment Features Requiring 
Test Procedure Action'' and ``Equipment Features Subject to Enforcement 
Policy,'' and remains central to providing clarity in DOE's 
regulations. Further, provisions more explicit than included in section 
D3 of AHRI 340/360-2022 are warranted to clarify treatment of models 
that include more than one optional component.
    In order to provide clarity between test procedure provisions 
(i.e., how to test a specific unit) and certification and enforcement 
provisions (e.g., which model to test), DOE is not proposing to adopt 
Appendix D of AHRI 340/360-2022 and instead is proposing related 
provisions in 10 CFR 429.43, 10 CFR 429.134, and 10 CFR part 431, 
subpart F, appendix C1.
3. Proposed Approach for Exclusion of Certain Components
    DOE's proposals for addressing treatment of certain components are 
discussed in the following sub-sections. Were DOE to adopt the 
provisions in 10 CFR 429.43, 10 CFR 429.134, and 10 CFR part 431, 
subpart F, appendix C1 as proposed, DOE would rescind the Commercial 
HVAC Enforcement Policy to the extent it is applicable to WSHPs.
    Issue 29: DOE seeks comment on its proposals regarding specific 
components in 10 CFR 429.43, 10 CFR 429.134, and 10 CFR part 431, 
subpart F, appendix C1.
a. Components Addressed Through Test Provisions of 10 CFR Part 431, 
Subpart F, Appendix C1
    In 10 CFR part 430, subpart F, appendix C1, DOE proposes test 
provisions for specific components, including all of the components 
listed in section D3 of AHRI 340/360-2022 for which there is a test 
procedure action which limits the impacts on measured efficiency (i.e., 
test procedure provisions specific to the component that are not 
addressed by general provisions in AHRI 340/360-2022 that negates the 
component's impact on performance). These provisions would specify how 
to test a unit with such a component (e.g., for a unit with hail 
guards, remove hail guards for testing). These proposed test provisions 
are consistent with the provision in section D3 of AHRI 340/360-2022 
but include revisions for further clarity and specificity (e.g., adding 
clarifying provisions for how to test units with modular economizers as 
opposed to units shipped with economizers installed). Specifically, DOE 
is proposing to require in appendix C1 that steps be taken during unit 
set-up and testing to limit the impacts on the measurement of these 
components:

 Desiccant Dehumidification Components
 Air Economizers
 Fresh Air Dampers
 Power Correction Capacitors

[[Page 53337]]

 Ventilation Energy Recovery Systems (VERS)
 Barometric Relief Dampers
 UV Lights
 Steam/Hydronic Coils
 Refrigerant Reheat
 Fire/Smoke/Isolation Dampers
 Process Heat Recovery/Reclaim Coils/Thermal Storage

    The components are listed and described in Table 12 in section 7 of 
the newly proposed Appendix C1, and test provisions for them are 
provided in the table.
b. Components Addressed Through Representation Provisions of 10 CFR 
429.43
    Consistent with the Commercial HVAC Term Sheet and the Commercial 
HVAC Enforcement Policy, DOE is proposing provisions that explicitly 
allow representations for individual models with certain components to 
be based on testing for individual models without those components--DOE 
is proposing a table (``Table 1 to 10 CFR 429.43'') at 10 CFR 
429.43(a)(3)(ii)(A) listing the components for which these provisions 
would apply. There are three components specified explicitly for WSHPs 
in the Commercial HVAC Enforcement Policy that are not included in 
section D3 of AHRI 340/360-2022: (1) Condenser Pumps/Valves/Fittings; 
(2) Condenser Water Reheat; and (3) Electric Resistance Heaters. DOE 
has tentatively concluded that the inclusion of these components as 
optional components for WSHPs is appropriate, except for electric 
resistance heaters. DOE has tentatively determined that electric 
resistance heaters would have a negligible effect on tested efficiency 
as they would be turned off for test and not impose a significant 
pressure drop. DOE is proposing the following components be listed in 
Table 1 to 10 CFR 429.43:

 Desiccant Dehumidification Components,
 Air Economizers,
 Ventilation Energy Recovery Systems (VERS),
 Steam/Hydronic Heat Coils,
 Refrigerant Reheat, Fire/Smoke/Isolation Dampers,
 Powered Exhaust/Powered Return Air Fans,
 Sound Traps/Sound Attenuators,
 Process Heat Recovery/Reclaim Coils/Thermal Storage,
 Indirect/Direct Evaporative Cooling of Ventilation Air,
 Condenser Pumps/Valves/Fittings,
 Condenser Water Reheat,
 Grill Options,
 Non-Standard Indoor Fan Motors

    In this NOPR, DOE is proposing to specify that the basic model 
representation must be based on the least efficient individual model 
that is a part of the basic model and clarifying how this long-standing 
basic model provision interacts with the component treatment in 10 CFR 
429.43 that is being proposed. DOE believes regulated entities may 
benefit from clarity in the regulatory text as to how the least-
efficient individual model within a basic model provision works with 
the component treatment for WSHPs. The amendments in this NOPR 
explicitly state that the exclusion of the specified components from 
consideration in determining basic model efficiency in certain 
scenarios is an exception to basing representations on the least 
efficient individual model within a basic model. In other words, the 
components listed in 10 CFR 429.43 are not being considered as part of 
the representation under DOE's regulatory framework if certain 
conditions are met as discussed in the following paragraphs, and, thus, 
their impact on efficiency is not reflected in the representation. In 
this case, the basic model's representation is generally determined by 
applying the testing and sampling provisions to the least-efficient 
individual model in the basic model that does not have a component 
listed in 10 CFR 429.43.
    DOE is proposing clarifying instructions for instances when 
individual models within a basic model may have more than one of the 
specified components and there may be no individual model without any 
of the specified components. DOE is proposing the concept of an 
``otherwise comparable model group'' (``OCMG''). An OCMG is a group of 
individual models within the basic model that do not differ in 
components that affect energy consumption as measured according to the 
applicable test procedure other than the specific components listed in 
Table 1 to 10 CFR 429.43 but may include individual models with any 
combination of such specified components. Therefore, a basic model can 
be composed of multiple OCMGs, each representing a unique combination 
of components that affect energy consumption as measured according to 
the applicable test procedure, other than the specified excluded 
components listed in Table 1 to 10 CFR 429.43. For example, a 
manufacturer might include two tiers of control system within the same 
basic model, in which one of the control systems has sophisticated 
diagnostics capabilities that require a more powerful control board 
with a higher wattage input. WSHP individual models with the 
``standard'' control system would be part of OCMG A, while individual 
models with the ``premium'' control system would be part of a different 
OCMG B, because the control system is not one of the specified exempt 
components listed in Table 1 to 10 CFR 429.43. However, both OCMGs may 
include different combinations of specified exempt components. Also, 
both OCMGs may include any combination of characteristics that do not 
affect the efficiency measurement, such as paint color.
    An OCMG is used to determine which individual models are used to 
determine a represented value. Specifically, when identifying the 
individual model within an OCMG for the purpose of determining a 
representation for the basic model, only the individual model(s) with 
the least number (which could be zero) of the specific components 
listed in Table 1 to 10 CFR 429.43 is considered. This clarifies which 
individual models are exempted from consideration for determination of 
represented values in the case of an OCMG with multiple specified 
components and no individual models with zero specific components 
listed in Table 1 to 10 CFR 429.43 (i.e., models with a number of 
specific components listed in Table 1 to 10 CFR 429.43 greater than the 
least number in the OCMG are exempted). In the case that the OCMG 
includes an individual model with no specific components listed in 
Table 1 to 10 CFR 429.43, then all individual models in the OCMG with 
specified components would be exempted from consideration. The least-
efficient individual model across the OCMGs within a basic model would 
be used to determine the representation of the basic model. In the case 
where there are multiple individual models within a single OCMG with 
the same non-zero least number of specified components, the least 
efficient of these would be considered.
    DOE relies on the term ``comparable'' as opposed to ``identical'' 
to indicate that for the purpose of representations, the components 
that impact energy consumption as measured by the applicable test 
procedure are the relevant components to consider. In other words, 
differences that do not impact energy consumption, such as unit color 
and presence of utility outlets, would not warrant separate OCMGs.
    The use of the OCMG concept results in the represented values of 
performance that are representative of the individual model(s) with the 
lowest

[[Page 53338]]

efficiency found within the basic model, excluding certain individual 
models with the specific components listed in Table 1 to 10 CFR 429.43. 
Further, the approach, as proposed, is structured to more explicitly 
address individual models with more than one of the specific components 
listed in Table 1 to 10 CFR 429.43, as well as instances in which there 
is no comparable model without any of the specified components. DOE 
developed a document of examples to illustrate the approach proposed in 
this NOPR for determining represented values for WSHPs with specific 
components, and in particular the OCMG concept. See EERE-2017-BT-TP-
0029.
    DOE's proposed provisions in 10 CFR 429.43(a)(3)(ii)(A) include 
each of the components specified in section D3 of AHRI 340/360-2022 for 
which the test provisions for testing a unit with these components may 
result in differences in ratings compared to testing a unit without 
these components, except for the following features: (1) Evaporative 
Pre-cooling of Condenser Intake Air; (2) Non-Standard Ducted Condenser 
Fans; and (3) Coated Coils. Because WSHPs do not have condenser intake 
air or condenser fans, DOE is not including provisions addressing these 
components for WSHPs. Non-standards indoor fan motors and coated coils 
are discussed in the following sub-sections.
(i) Non-Standard Indoor Fan Motors
    The Commercial HVAC Enforcement Policy includes high-static indoor 
blowers/oversized motors as an optional feature for WSHPs, among other 
equipment. The Commercial HVAC Enforcement Policy states that when 
selecting a unit of a basic model for DOE[hyphen]initiated testing, if 
the basic model includes a variety of high-static indoor blowers or 
oversized motor options,\36\ DOE will test a unit that has a standard 
indoor fan assembly (as described in the STI that is part of the 
manufacturer's certification, including information about the standard 
motor and associated drive that was used in determining the certified 
rating). This policy only applies where: (a) the manufacturer 
distributes in commerce a model within the basic model with the 
standard indoor fan assembly (i.e., standard motor and drive), and (b) 
all models in the basic model have a motor with the same or better 
relative efficiency performance as the standard motor included in the 
test unit, as described in a separate guidance document discussed 
subsequently. If the manufacturer does not offer models with the 
standard motor identified in the STI or offers models with high-static 
motors that do not comply with the comparable efficiency guidance, DOE 
will test any indoor fan assembly offered for sale by the manufacturer.
---------------------------------------------------------------------------

    \36\ The Commercial HVAC Enforcement Policy defines ``high 
static indoors blower or oversized motor'' as an indoor fan 
assembly, including a motor, that drives the fan and can deliver 
higher external static pressure than the standard indoor fan 
assembly sold with the equipment.
---------------------------------------------------------------------------

    DOE subsequently issued a draft guidance document (``Draft 
Commercial HVAC Guidance Document'') on June 29, 2015 to request 
comment on a method for comparing the efficiencies of a standard motor 
and a high-static indoor blower/oversized motor.\37\ As presented in 
the Draft Commercial HVAC Guidance Document, the relative efficiency of 
an indoor fan motor would be determined by comparing the percent losses 
of the standard indoor fan motor to the percent losses of the non-
standard (oversized) indoor fan motor. The percent losses would be 
determined by comparing each motor's wattage losses to the wattage 
losses of a corresponding reference motor. Additionally, the draft 
method contains a table that includes a number of situations with 
different combinations of characteristics of the standard motor and 
oversized motor (e.g., whether each motor is subject to Federal 
standards for motors, whether each motor can be tested to the Federal 
test procedure for motors, whether each motor horsepower is less than 
one) and specifies for each combination whether the non-standard fan 
enforcement policy would apply (i.e., whether DOE would not test a 
model with an oversized motor, as long as the relative efficiency of 
the oversized motor is at least as good as performance of the standard 
motor). DOE has not issued a final guidance document and is instead 
addressing the issue for WSHPs in this test procedure rulemaking.
---------------------------------------------------------------------------

    \37\ Available at www1.eere.energy.gov/buildings/appliance_standards/pdfs/draft-commercial-hvac-motor-faq-2015-06-29.pdf.
---------------------------------------------------------------------------

    Neither ISO 13256-1:1998 nor ISO 13256-1:2021 address this issue. 
Section D4.1 of AHRI 340/360-2022 provides an approach for including an 
individual model with a non-standard indoor fan motor as part of the 
same basic model as an individual model with a standard indoor fan 
motor. Under the approach in section D4.1 of AHRI 340/360-2022, the 
non-standard indoor fan motor efficiency must exceed the minimum value 
calculated using Equation D1 of AHRI 340/360-2022. This minimum non-
standard motor efficiency calculation is dependent on the efficiency of 
the standard fan motor and the reference efficiencies (determined per 
Table D1 of AHRI 340/360-2022) of the standard and non-standard fan 
motors.
    Section D4.2 of AHRI 340/360-2022 contains a method for how to 
compare performance for integrated fans and motors (``IFMs''). Because 
the fan motor in an IFM is not separately rated from the fan, this 
method compares the performance of the entire fan-motor assemblies for 
the standard and non-standard IFMs, rather than just the fan motors. 
This approach enables comparing relative performance of standard and 
non-standard IFMs, for which motor efficiencies could otherwise not be 
compared using the method specified in section D4.1 of AHRI 340/360-
2022. Specifically, this method determines the ratio of the input power 
of the non-standard IFM to the input power of the standard IFM at the 
same duty point as defined in section D4.2 (i.e., operating at the 
maximum ESP for the standard IFM at the rated airflow). If the input 
power ratio does not exceed the maximum ratio specified in Table D3 of 
AHRI 340/360-2022, the individual model with the non-standard IFM may 
be included within the same basic model as the individual model with 
the standard IFM. Section D4.2 of AHRI 340/360-2022 allows these 
calculations to be conducted using either test data or simulated 
performance data.
    The approaches in section D4 of AHRI 340/360-2022 for non-standard 
indoor fan motors and non-standard indoor IFMs generally align with the 
approaches of the Commercial HVAC Term Sheet, the Commercial HVAC 
Enforcement Policy, and the Draft Commercial HVAC Guidance Document, 
while providing greater detail and accommodating a wider range of fan 
motor options. For the reasons presented in the preceding paragraphs 
DOE proposes to adopt the provisions for comparing performance of 
standard and non-standard indoor fan motors/IFMs in section D4 of AHRI 
340/360-2022 \38\ for the determination of the represented efficiency 
value for WSHPs at 10 CFR 429.43(a)(3) and for DOE assessment and 
enforcement testing of WSHPs at 10 CFR 429.134(t)(2). Were DOE to adopt 
the provisions of section D4 of Appendix D of AHRI 340/360-2022 as 
proposed, the Commercial

[[Page 53339]]

HVAC Enforcement Policy and draft guidance document, to the extent 
applicable to WSHPs, would no longer apply.
---------------------------------------------------------------------------

    \38\ Per DOE's existing certification regulations, if a 
manufacturer were to use the proposed approach to certify a basic 
model, the manufacturer would be required to maintain documentation 
of how the relative efficiencies of the standard and non-standard 
fan motors or the input powers of the standard and non-standard IFMs 
were determined as well as the supporting calculations. See 10 CFR 
429.71.
---------------------------------------------------------------------------

    Issue 30: DOE requests comment on its proposal to adopt the methods 
for comparing relative efficiency of standard and non-standard indoor 
fan motors and integrated fan and motor combinations specified in 
section D4 of AHRI 340/360-2022 in the provisions for determination of 
represented values in 10 CFR 429.43(a) and provisions for DOE 
assessment and enforcement testing in 10 CFR 429.134.
(ii) Coated Coils
    DOE is proposing to exclude coated coils from the specific 
components list specified in 10 CFR 429.43 because DOE has tentatively 
concluded that the presence of coated coils does not result in a 
significant impact to performance of WSHPs, and, therefore, models with 
coated coils should be rated based on performance of models with coated 
coils present (rather than based on performance of an individual model 
within an OCMG without coated coils).
c. Enforcement Provisions of 10 CFR 429.134
    Consistent with the Commercial HVAC Term Sheet and the Commercial 
HVAC Enforcement Policy, DOE is proposing provisions in the newly 
proposed 10 CFR 429.134(t)(1) regarding how DOE would assess compliance 
for basic models that include individual models distributed in commerce 
if DOE cannot obtain for testing individual models without the 
components that are the basis of representation. Specifically, DOE 
proposes that if a basic model includes individual models with 
components listed at Table 1 to 10 CFR 429.43 and DOE is not able to 
obtain an individual model with the least number of those components 
within an OCMG (as defined in 10 CFR 429.43(a)(3) and discussed in 
section III.G.3.b of this NOPR), DOE may test any individual model 
within the OCMG.
d. Testing Specially-Built Units That Are Not Distributed in Commerce
    Unlike section D3 of AHRI 340/360-2022, DOE's Commercial HVAC 
Enforcement Policy does not allow a manufacturer to test a specially-
built model for testing models without a feature that are not 
distributed in commerce. Because testing such specially-built models 
would not provide ratings representative of equipment distributed in 
commerce, DOE has tentatively concluded that this approach is not 
appropriate. Therefore, consistent with the Commercial HVAC Enforcement 
Policy, DOE is not proposing to allow testing of specially-built units 
in its representation and enforcement provisions.

H. Represented Values and Enforcement

1. Cooling Capacity
    For WSHPs, cooling capacity determines equipment class, which in 
turn determines the applicable energy conservation standard. 10 CFR 
431.97. While cooling capacity is a required represented value for 
WSHPs, DOE does not currently specify any provisions for WSHPs 
regarding how close the represented value of cooling capacity must be 
to the tested or AEDM-simulated cooling capacity, or whether DOE will 
use measured or certified cooling capacity to determine equipment class 
for enforcement testing. In contrast, at paragraphs (a)(1)(iv) and 
(a)(2)(ii) of 10 CFR 429.43 and paragraph (g) of 10 CFR 429.134, DOE 
specifies such provisions regarding the cooling capacity for air-cooled 
CUACs (``ACUACs''). Because energy conservation standards for WSHPs are 
dependent on cooling capacity, inconsistent approaches to the 
application of cooling capacity between basic models could result in 
inconsistent determinations of equipment class and, in turn, 
inconsistent applications of the energy conservation standards.
    Accordingly, DOE is proposing to add the following provisions 
regarding cooling capacity for WSHPs: (1) a requirement that the 
represented cooling capacity be between 95 percent and 100 percent of 
the tested or AEDM-simulated cooling capacity; and (2) an enforcement 
provision stating that DOE would use the mean of measured cooling 
capacity values from assessment and enforcement testing, rather than 
the certified cooling capacity, to determine the applicable standards.
    First, DOE proposes to require in 10 CFR 429.43(a)(3)(ii)(B) that 
the represented value of cooling capacity must be between 95 percent 
and 100 percent of the mean of the cooling capacity values measured for 
the units in the sample (if determined through testing), or between 95 
percent and 100 percent of the net sensible cooling capacity output 
simulated by an AEDM. This tolerance would help to ensure that 
equipment: (1) is capable of performing at the cooling capacity for 
which it is represented to commercial consumers and (2) certified in 
the appropriate equipment class for the cooling capacity the equipment 
is capable of providing. This tolerance would also enable manufacturers 
to conservatively rate the cooling capacity to allow for minor 
variations in the capacity measurements from different units tested at 
different laboratories.
    Second, DOE is proposing in its product-specific enforcement 
provisions at 10 CFR 429.134(t)(1) that the cooling capacity of each 
tested unit of the basic model will be measured pursuant to the test 
requirements of part 431 and that the mean of the measurements will be 
used to determine compliance with the applicable standards.
    As discussed in this section, applicable energy conservation 
standards for WSHPs are dependent on the rated cooling capacity. 
Consequently, in certain cases, over-rating a system could result in 
decreased stringency by incorrectly applying a more lenient standard 
prescribed for a higher capacity equipment class. DOE has tentatively 
concluded that these proposals would result in more accurate ratings of 
cooling capacity, thereby ensuring appropriate application of the 
energy conservation standards, while providing flexibility for 
conservatively rating cooling capacity to ensure that equipment is 
capable of delivering the cooling capacity that is represented to 
commercial consumers.
    Issue 31: DOE requests comment on its proposals related to 
represented values and verification testing of cooling capacity for 
WSHPs.
2. Enforcement of IEER
    As discussed in section III.E.1 of this document, DOE is proposing 
two options for determining IEER. The first option, ``Option 1'' as 
specified in section 5.1.1 of appendix C1, is based on testing at the 
IEER entering water temperatures. The second option, ``Option 2'' as 
specified in section 5.1.2 of appendix C1, is based on testing at 
alternate entering water temperatures and then using interpolation and 
extrapolation to determine performance at IEER entering water 
temperatures. For assessment or enforcement testing, DOE is proposing 
provisions in Sec.  429.134(t)(3) specifying that that the Department 
will determine IEER according to the ``Option 1'' approach, unless the 
manufacturer has specified that the ``Option 2'' approach should be 
used for the purposes of enforcement, in which case the Department will 
determine IEER according to the ``Option 2'' approach.

I. Test Procedure Costs and Impact

    EPCA requires that the test procedures for commercial package air 
conditioning and heating equipment, which includes WSHPs, be those

[[Page 53340]]

generally accepted industry testing procedures or rating procedures 
developed or recognized by AHRI or by ASHRAE, as referenced in ASHRAE 
Standard 90.1. (42 U.S.C. 6314(a)(4)(A)) Further, if such an industry 
test procedure is amended, DOE must amend its test procedure to be 
consistent with the amended industry test procedure, unless DOE 
determines, by rule published in the Federal Register and supported by 
clear and convincing evidence, that such amended test procedure would 
not meet the requirements in 42 U.S.C. 6314(a)(2) and (3) related to 
representative use and test burden. (42 U.S.C. 6314(a)(4)(B)) DOE 
proposes to reorganize the current test procedure in proposed appendix 
C and to adopt generally through incorporation by reference the 
industry standard AHRI 340/360-2022 in proposed appendix C1. As 
discussed, the proposed test procedure in proposed appendix C1 would 
rely on the IEER metric. Testing pursuant to proposed appendix C1 would 
be required only at such time as compliance is required with amended 
energy conservation standards based on IEER and the amended COP, should 
DOE adopt such standards, or if a manufacturer chooses to make 
voluntary representations of IEER before the compliance date.
    As discussed in section III.D.3 of this NOPR, DOE has tentatively 
determined that the proposed test procedure in proposed appendix C1 
would improve representativeness, accuracy, and reproducibility as 
compared to the current DOE test procedure and would not be unduly 
burdensome to conduct.
    Because the current DOE test procedure for WSHPs would be relocated 
to appendix C without change, the proposed test procedure in appendix C 
for measuring EER and COP would result in no change in testing 
practices or burden.
    DOE tentatively concludes that the proposed test procedure in 
proposed appendix C1 for measuring IEER and COP would increase testing 
costs per unit compared to the current DOE test procedure. DOE 
estimates to cost for third-party laboratory testing of WSHPs according 
to the current test procedure to be $2,200 per unit for units with a 
cooling capacity of less than 135,000 Btu/h. DOE estimates the cost for 
third-party lab testing according to the proposed appendix C1 for 
measuring IEER and COP would be $4,450 per unit for units with a 
cooling capacity of less than 135,000 Btu/h. This increase is due to 
the increased number of tests associated with the IEER metric compared 
to the current metric, EER. IEER requires four tests, whereas EER only 
requires one.
    Additionally, DOE is proposing to increase in the scope of 
applicability of the test procedure to include all WSHPs with full-load 
cooling capacity between 135,000 Btu/h and 760,000 Btu/h. DOE estimates 
the cost for third-party lab testing of large and very large WSHPs 
according to the proposed appendix C1 for measuring IEER and COP would 
be $12,000 per unit. DOE estimates a substantially higher cost for 
larger WSHPs because they are generally more difficult to set up due to 
size and larger units typically would need to be set up in larger and 
rarer test chambers.
    As discussed, in accordance with 10 CFR 429.70, WSHP manufacturers 
may elect to use AEDMs. 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. DOE 
estimates the per-manufacturer cost to develop and validate an AEDM to 
be used for all WSHP equipment with a cooling capacity less than 
135,000 Btu/h would be $12,800. DOE estimates the per-manufacturer cost 
to develop and validate an AEDM to be used for all WSHPs with a cooling 
capacity between 135,000 Btu/h and 760,000 Btu/h would be $27,900. DOE 
estimates an additional cost of approximately $41 per basic model for 
determining energy efficiency using the validated AEDM.\39\
---------------------------------------------------------------------------

    \39\ DOE estimated initial costs to validate an AEDM assuming 80 
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 a engineering technician wage of $41 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 technician wage of $41 per hour.
---------------------------------------------------------------------------

    As discussed in section III.J of this NOPR, the proposed test 
procedure provisions regarding IEER would not be mandatory until 
compliance is required with amended energy conservation standards that 
rely on IEER, should DOE adopt such standards, although any voluntary 
early representations of IEER must be based on the proposed appendix 
C1. DOE has tentatively determined that the test procedure amendments, 
if finalized, would not require manufacturers to redesign any of the 
covered equipment or require changes to how the equipment is 
manufactured, solely as result of the test procedure amendments. In 
section IV.B of this TP NOPR, DOE assesses the impact to domestic, 
small manufacturers of WSHPs from the test procedure provisions 
proposed in this NOPR.
    Issue 32: DOE requests comment on its understanding of the impact 
of the test procedure proposals in this NOPR. DOE also seeks specific 
feedback on the estimated costs to rate WSHP models with an AEDM.

J. Compliance Date

    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 360 days after 
publication of such a test procedure final rule in the Federal 
Register. (42 U.S.C. 6314(d)(1))
    Starting 360 days after publication of a test procedure final rule 
in the Federal Register, and prior to the compliance date of amended 
standards for water-source heat pumps that rely on IEER, 
representations would need to be based the proposed appendix C. 
Starting on the compliance date of amended standards for water-source 
heat pumps that rely on IEER, if adopted, representations would need to 
be based the proposed appendix C1.
    Any voluntary representations of IEER made prior to the compliance 
date of amended standards for water-source heat pumps that rely on IEER 
would need to be based on the proposed appendix C1 starting 360 days 
after publication of such a test procedure final rule in the Federal 
Register, and manufacturers may use appendix C1 to certify compliance 
with any amended standards based on IEER, if adopted, prior to the 
applicable compliance date those energy conservation standards.

IV. Procedural Issues and Regulatory Review

A. Review Under Executive Orders 12866 and 13563

    Executive Order (``E.O.'') 12866, ``Regulatory Planning and 
Review,'' 58 FR 51735 (Oct. 4, 1993), 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

[[Page 53341]]

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'') in the Office of Management and Budget (``OMB'') 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 (August 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. DOE 
reviewed this proposed rule to amend the test procedure of WSHPs under 
the provisions of the Regulatory Flexibility Act and the policies and 
procedures published on February 19, 2003.
    The following sections detail DOE's IRFA for this test procedure 
rulemaking.
1. Description of Reasons Why Action Is Being Considered
    DOE is proposing to amend the existing DOE test procedures for 
water-source heat pumps (``WSHPs''). DOE must update the Federal test 
procedures to be consistent with relevant industry test procedures 
unless DOE determines by rule published in the Federal Register and 
supported by clear and convincing evidence that the industry test 
procedure would not be representative of an average use cycle or would 
be unduly burdensome to conduct. (42 U.S.C. 6314(a)(4)(B))
2. Objective of, and Legal Basis for, Rule
    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 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))
    With respect to WSHPs, EPCA requires that the test procedures shall 
be those generally accepted industry testing procedures or rating 
procedures developed or recognized by the Air-Conditioning, Heating, 
and Refrigeration Institute (``AHRI'') or by the American Society of 
Heating, Refrigerating and Air-Conditioning Engineers (``ASHRAE''), as 
referenced in ASHRAE Standard 90.1, ``Energy Standard for Buildings 
Except Low-Rise Residential Buildings'' (``ASHRAE Standard 90.1''). (42 
U.S.C. 6314(a)(4)(A)) Further, if such an industry test procedure is 
amended, DOE must amend its test procedure to be consistent with the 
amended industry test procedure, unless DOE determines, by rule 
published in the Federal Register and supported by clear and convincing 
evidence, that the amended test procedure would not produce test 
results that reflect the energy efficiency, energy use, and estimated 
operating costs of that equipment during a representative average use 
cycle or would be unduly burdensome to conduct. (42 U.S.C. 
6314(a)(4)(B))
    EPCA also requires that, at least once every 7 years, DOE evaluate 
test procedures for each type of covered equipment including WSHPs, to 
determine whether amended test procedures would more accurately or 
fully comply with the requirements for the test procedures to be 
reasonably designed to produce test results that reflect energy 
efficiency, energy use, and estimated operating costs during a 
representative average use cycle and not be unduly burdensome to 
conduct. (42 U.S.C. 6314(a)(1)(A))
    DOE is proposing amendments to the test procedures for WSHPs in 
satisfaction of its statutory obligations under EPCA.
3. Description and Estimate of Small Entities Regulated
    DOE uses the Small Business Administration (``SBA'') small business 
size standards to determine whether manufacturers qualify as ``small 
businesses,'' which are listed by the North American Industry 
Classification System (``NAICS'').\40\ The SBA considers a business 
entity to be small business if, together with its affiliates, it 
employs less than a threshold number of workers specified in 13 CFR 
part 121.
---------------------------------------------------------------------------

    \40\ 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 July 16, 2021).
---------------------------------------------------------------------------

    WSHP manufacturers, who produce the equipment covered by this rule, 
are classified under NAICS code 333415, ``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. This employee threshold includes all employees in a 
business's parent company and any other subsidiaries.
    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. The Department conducted a 
focused inquiry into small business manufacturers of the equipment 
covered by this rulemaking. DOE's analysis relied on publicly available 
information and databases to identify potential small businesses that 
manufacture WSHPs domestically. DOE utilized the California Energy 
Commission's Modernized Appliance Efficiency

[[Page 53342]]

Database System (``MAEDbS'') \41\ and the DOE's Certification 
Compliance Database (``CCD'') \42\ in identifying manufacturers. DOE 
screened out private labelers because original equipment manufacturers 
(``OEMs'') would likely be responsible for any costs associated with 
testing to the proposed test procedure. As a result of this inquiry, 
DOE identified a total of 25 OEMs of WSHPs in the United States 
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 25 OEMs of WSHPs, DOE identified seven as small, 
domestic manufacturers for consideration. DOE used subscription-based 
business information tools to determine headcount and revenue of these 
small businesses.
---------------------------------------------------------------------------

    \41\ MAEDbS is available at www.cacertappliances.energy.ca.gov/Pages/Search/AdvancedSearch.aspx (Last accessed Dec. 1, 2021).
    \42\ Certified equipment in the CCD are listed by product class 
and can be accessed at www.regulations.doe.gov/certification-data/ 
(Last accessed Dec. 1, 2021).
---------------------------------------------------------------------------

4. Description and Estimate of Compliance Requirements
    In this NOPR, DOE proposes to add new appendices C and C1 to 
subpart F of part 431, both titled ``Uniform test method for measuring 
the energy consumption of water-source heat pumps,'' (``appendix C'' 
and ``appendix C1,'' respectively). The current DOE test procedure for 
WSHPs would be relocated to appendix C without change. DOE is proposing 
in appendix C1 to adopt generally the industry test standard AHRI 340/
360-2022 for WSHPs, with certain additional provisions regarding test 
conditions to improve representativeness, accuracy, and repeatability. 
Appendix C1 would be for determining IEER, and use of appendix C1 would 
not be required until such time as compliance is required with amended 
energy conservation standards for WSHPs based on IEER (should DOE adopt 
such standards) or should a manufacturer choose to make voluntary 
representations of IEER. Additionally, DOE is proposing to increase the 
scope of applicability of the test procedure (including both appendices 
C and C1) to include all WSHPs with a full-load cooling capacity 
between 135,000 Btu/h and 760,000 Btu/h. Lastly, this NOPR seeks to 
amend certain representation and enforcement provisions for WSHPs in 10 
CFR part 429.
    Appendix C does not contain any changes from the current Federal 
test procedure, and, therefore, would have no cost to industry and 
would not require retesting solely as a result of DOE's adoption of 
this proposed amendment to the test procedure, if made final.
    In appendix C1, DOE is proposing to adopt generally AHRI 340/360-
2022 as the test procedure for WSHPs. The proposed test procedure in 
appendix C1 includes provisions for measuring efficiency of WSHPs in 
terms of the IEER metric for cooling mode and the COP metric for 
heating mode. Appendix C1 is not mandatory at this point in time. 
Should DOE adopt energy conservation standards based on the proposed 
metrics in appendix C1 (IEER and COP) in the future, DOE anticipates 
manufacturers would incur costs to re-rate models as a result of the 
standards. The current DOE test procedure (applicable only to WSHP with 
cooling capacity less than 135,000 Btu/h) results in costs of 
approximately $2,200 per unit for third-party laboratory testing. DOE 
estimates the cost for third-party laboratory testing according to the 
proposed appendix C1 to be $4,450 per unit.
    Furthermore, as mentioned, DOE is proposing to increase in the 
scope of applicability of the test procedure to include all WSHPs with 
a full-load cooling capacity between 135,000 Btu/h and 760,000 Btu/h. 
However, testing for these WSHPs is not currently mandatory because 
there are no energy conservation standards for WSHPs at or above 
135,000 Btu/h at the present time. Consequently, manufacturers would 
not incur costs as result of this TP NOPR unless they choose to make 
voluntary representations regarding the IEER of the subject equipment. 
Any voluntary representations would need to be based on the test 
procedure in appendix C starting 360 days after the publication of a 
test procedure final rule. Should DOE adopt future energy conservation 
standards denominated in terms of IEER to expand coverage of WSHPs with 
a full-load cooling capacity between 135,000 Btu/h and 760,000 Btu/h, 
DOE manufacturers could incur first-time rating costs as a result of 
the standard. DOE estimates the cost for third-party lab testing 
according to the proposed appendix C1 for measuring IEER and COP of 
WSHPs with a cooling capacity between 135,000 Btu/h and 760,000 Btu/h 
to be $12,000 per unit.
    If WSHP manufacturers conduct physical testing to certify a basic 
model, two units are required to be tested per basic model. The 
physical test cost, according to the proposed amendments, would range 
between $8,900 to $24,000 per basic model.\43\ However, manufacturers 
may elect to use AEDMs.\44\ 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. 
DOE's requirements for validation of AEDMs at 10 CFR 429.70(c)(2)(iv) 
specify that an AEDM validated with testing of two WSHP basic models 
can be used to develop ratings for WSHPs of any cooling capacity. If a 
manufacturer chooses to update and validate an AEDM for WSHPs based on 
testing a model with a cooling capacity less than 135,000 Btu/h, DOE 
estimates the cost would be $12,800. If a manufacturer chooses to 
update and validate an AEDM for WSHPs based on testing a model with a 
cooling capacity greater than or equal to 135,000 Btu/h, DOE estimates 
the cost would be $27,900.\45\ Additionally, DOE estimates a cost of 
approximately $41 per basic model for determining energy efficiency 
using the validated AEDM.
---------------------------------------------------------------------------

    \43\ The cost to test one unit with a cooling capacity less than 
135,000 Btu/h is $4,450, so the cost to test two units is $8,900. 
The cost to test one unit with a cooling capacity greater than 
135,000 Btu/h is $12,000, so the cost to test two units is $24,000.
    \44\ In accordance with 10 CFR 429.70.
    \45\ DOE estimated initial costs to validate an AEDM assuming 80 
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 a engineering technician wage of $41 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 technician wage of $41 per hour.
---------------------------------------------------------------------------

    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 that small business manufacturers 
will afford themselves of the cost-saving opportunity associated with 
use of an AEDM.
    DOE identified seven small, domestic OEMs of WSHPs that manufacture 
equipment impacted by DOE's proposal to adopt metrics in terms of IEER 
and COP. Additionally, of these manufacturers, DOE identified one OEM 
that currently manufactures equipment with a cooling capacity between 
135,000 Btu/h and 760,000 Btu/h. DOE estimates

[[Page 53343]]

the range of potential costs to these small businesses as follows.
    Given the potential for DOE to adopt energy conservation standards 
based on the proposed metrics in 10 CFR part 431, subpart F, appendix 
C1 (IEER and COP) in the future, DOE estimates here the range of 
potential re-rating costs for the seven small, domestic OEMs. The 
small, domestic OEMs manufacture an average of 38 basic models per 
manufacturer and average $14.0 million in annual revenue. DOE estimates 
that the associated re-rating costs for these seven manufacturers would 
be approximately $14,400 per manufacturer, when utilizing AEDMs. 
Therefore, the average cost to re-rate all basic models is estimated to 
be less than 1 percent of annual revenue for these small businesses.
    Should DOE adopt future energy conservation standards to include 
all WSHPs with a cooling capacity between 135,000 Btu/h and 760,000 
Btu/h, DOE estimates that the one small, domestic manufacturer of this 
equipment-type would incur first-time rating costs of $28,100 while 
making use of an AEDM. DOE estimates this manufacturer to have an 
annual revenue of $11.0 million. Therefore, should DOE adopt future 
energy conservation standards to include all WSHPs with a cooling 
capacity between 135,000 Btu/h and 760,000 Btu/h and this manufacturer 
were required to re-rate all its models to the proposed metrics in 10 
CFR part 431, subpart F, appendix C1 (IEER and COP). DOE estimates the 
cost would be less than 1 percent of annual revenue for this small 
business.\46\
---------------------------------------------------------------------------

    \46\ DOE estimated the cumulative burden to represent $42,500.
---------------------------------------------------------------------------

    Issue 33: DOE requests comment on the number of small OEMs DOE 
identified. DOE also seeks comment on the Department's estimates of 
potential costs these small manufacturers may incur as a result of its 
proposed amendments to the WSHP test procedure.
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.
6. Significant Alternatives to the Rule
    The discussion in the previous section analyzes impacts on small 
businesses that would be expected to result from DOE's proposed test 
rule, if finalized. The Department has tentatively determined that 
there are no better alternatives than the test procedure proposed in 
this NOPR, in terms of both meeting the agency's objectives pursuant to 
EPCA and reducing burden. Whenever possible, DOE seeks to utilize 
applicable industry test procedures as a way to minimize burdens on 
regulated parties. In reviewing alternatives to the proposed test 
procedure, DOE examined other industry test procedures when applicable. 
Ultimately, DOE proposes to amend the test procedure for WSHPs to 
incorporate by reference AHRI 340/360-2022, the industry test procedure 
for testing CUAC/HPs. Furthermore, AHRI 340/360-2022 in turn references 
ANSI/ASHRAE 37-2009, which provides a method of test applicable to many 
categories of air conditioning and heating equipment. DOE has 
tentatively concluded that incorporation by reference of these industry 
test standards would best achieve the statutory objectives of 
representativeness and not being unduly burdensome on manufacturers, 
including small businesses.
    Additionally, 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 WSHP models. Without AEDMs, DOE estimates the typical 
cost to physically test all WSHP basic models for an average small 
manufacturer would be $340,000.
    Additional compliance flexibilities may be available through other 
means. Manufacturers subject to DOE's energy conservation 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 WSHPs must certify to DOE that their equipment 
complies with any applicable energy conservation standards. To certify 
compliance, manufacturers must first obtain test data for their 
equipment 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 
WSHPs. (See generally 10 CFR part 429.) The collection-of-information 
requirement for the certification and recordkeeping is subject to 
review and approval by 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 WSHPs in this NOPR. Instead, DOE may consider 
proposals to amend the certification requirements and reporting for 
WSHPs 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 will be used to develop and implement future energy 
conservation standards for WSHPs. 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 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. Accordingly, neither an 
environmental assessment nor an environmental impact statement is 
required.

E. Review Under Executive Order 13132

    Executive Order 13132, ``Federalism,'' 64 FR 43255 (August 10, 
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

[[Page 53344]]

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 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 if 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 www.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 
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 WSHPs 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.

[[Page 53345]]

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 Federal test procedure for WSHPs 
would incorporate testing methods contained in certain sections of the 
following applicable commercial test standards: AHRI 340/360-2022 and 
ANSI/ASHRAE 37-2009. 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 test standards:

    AHRI 340/360-2022 is an industry-accepted test procedure for 
measuring the performance of unitary air-conditioning & air-source 
heat pump equipment. AHRI Standard 340/360-2022 is reasonably 
available on AHRI's website at: www.ahrinet.org/.
    ANSI/ASHRAE 37-2009, as updated by the errata sheet, is an 
industry-accepted test procedure for measuring the performance of 
electrically driven unitary air-conditioning and heat pump 
equipment. ANSI/ASHRAE 37-2009 is reasonably available on ANSI's 
website at: https://webstore.ansi.org/.
    ASHRAE errata sheet to ANSI/ASHRAE Standard 37-2009 is a 
technical corrections sheet for ANSI/ASHRAE 37-2009. The errata 
sheet for ANSI/ASHRAE 37-2009 is reasonably available on ASHRAE's 
website at: www.ashrae.org/.
    ISO Standard 13256-1:1998 is an industry-accepted test procedure 
for measuring the performance of water-source heat pump equipment. 
ISO Standard 13256-1:1998 is reasonably available on ISO's website 
at: https://webstore.ansi.org/.

    The following standards were previously-approved for incorporation 
by reference in the locations where they appear in the regulatory text: 
AHRI 210/240-2008, AHRI 340/360-2007, AHRAE 127-2007, AHRI 1230-2010, 
AHRI 390-2003.

V. Public Participation

A. Participation in the Public Meeting 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: 
https://www.energy.gov/eere/buildings/public-meetings-and-comment-deadlines. Participants are responsible for ensuring their systems are 
compatible with the webinar software.
    Additionally, you may request an in-person meeting to be held prior 
to the close of the request period provided in the DATES section of 
this document. Requests for an in-person meeting may be made by 
contacting Appliance and Equipment Standards Program staff at (202) 
287-1445 or by email: [email protected].

B. Procedure for Submitting Prepared General Statements for 
Distribution

    Any person who has an interest in the topics addressed in this 
NOPR, 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 public meeting webinar. Such persons may submit 
requests to speak via email to the Appliance and Equipment Standards 
Program at: [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 rulemaking and the topics they 
wish to discuss. Such persons should also provide a daytime telephone 
number where they can be reached.
    DOE requests persons selected to make an oral presentation to 
submit an advance copy of their statement 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 Public Meeting Webinar

    DOE will designate a DOE official to preside at the public meeting 
webinar 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 public meeting webinar. 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 public meeting webinar and until the end of the comment period, 
interested parties may submit further comments on the proceedings and 
any aspect of the rulemaking.
    The webinar will be conducted in an informal, conference style. DOE 
will present a general overview of the topics addressed in this 
rulemaking, allow time for prepared general statements by participants, 
and encourage all interested parties to share their views on issues 
affecting this 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 allow, 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 and comment on 
statements made by others. 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 rulemaking. The official conducting the 
webinar 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 public meeting webinar.
    A transcript of the public meeting webinar will be included in the 
docket,

[[Page 53346]]

which can be viewed as described in the Docket section at the beginning 
of this document. 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.\47\ Interested parties may submit 
comments, data, and other information using any of the methods 
described in the ADDRESSES section at the beginning of this document.
---------------------------------------------------------------------------

    \47\ 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 itself 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. Otherwise, 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 in a cover letter. Include your first 
and last names, email address, telephone number, and optional mailing 
address. With this instruction followed, 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 telefacsimiles (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 comments on the proposed expansion of the 
scope of applicability of the Federal test procedure to include WSHPs 
with cooling capacity between 135,000 and 760,000 Btu/h.
    Issue 2: DOE requests comments on the proposed change to the 
definition of WSHP to explicitly indicate that WSHP is a category of 
commercial package air-conditioning and heating equipment, and to 
clarify that the presence of an indoor fan does not apply to coil-only 
units.
    Issue 3: DOE requests comment on its proposal to adopt the test 
methods specified in AHRI 340/360-2022 for calculating the IEER of 
WSHPs. DOE also requests comment on its proposal that all EER tests at 
full-load and part-load conditions specified in Table 1 of ISO 13256-
1:1998 (i.e., full-load tests at 86 [deg]F, 77 [deg]F, and 59 [deg]F 
and part-load tests at 86 [deg]F, 68 [deg]F, and 59 [deg]F) are 
optional.
    Issue 4: DOE requests comment on the proposal to allow 
determination of IEER using two different methods: (1) testing in 
accordance with AHRI 340/360-2022; or (2) interpolation and 
extrapolation of cooling capacity and power values based on testing in 
accordance with the proposed test procedure at the EWTs specified in 
Table 1 of ISO 13256-1:1998. Specifically, DOE seeks feedback on the 
proposed method for calculating IEER via interpolation and 
extrapolation, and on whether this approach would serve as a potential 
burden-reducing option as compared to

[[Page 53347]]

testing at the AHRI 340/360-2022 conditions.
    Issue 5: DOE requests comment on whether the proposed methodology 
to determine IEER based on interpolation and extrapolation is 
appropriate for variable-speed units. DOE would consider requiring 
variable-speed equipment be tested only according to AHRI 340/360-2022 
and, thus, testing physically at the IEER EWTs, if suggested by 
commenters.
    Issue 6: DOE seeks feedback on whether the proposed interpolation 
and extrapolation method should be based on testing at the ISO 13256-
1:2021 EWTs.
    Issue 7: DOE seeks comment and data on the representativeness of 55 
[deg]F as the EWT condition for determining COP. Specifically, DOE 
requests feedback and data on whether a lower EWT, such as 50 [deg]F, 
would be more representative of heating operation of WSHPs. DOE will 
further consider any alternate EWT suggested by comments in developing 
any final rule.
    Issue 8: DOE requests comment on the proposal to allow 
determination of COP using two different methods: (1) testing at 55 
[deg]F; or (2) interpolation of heating capacity and power values based 
on testing in accordance with the proposed test procedure at EWTs 
specified for heating tests in Table 2 of ISO 13256-1:1998 (i.e., 50 
[deg]F and 68 [deg]F). Specifically, DOE seeks feedback on the proposed 
method for calculating COP via interpolation, and on whether this 
approach would serve as a potential burden-reducing option as compared 
to testing at 55 [deg]F.
    Issue 9: DOE requests comment on its proposal to specify in 
proposed appendix C1 use of the cooling entering air conditions from 
AHRI 340/360-2022 (i.e., 80 [deg]F dry-bulb temperature and 67 [deg]F 
wet-bulb temperature) and the heating entering air conditions from AHRI 
340/360-2022 (i.e., 70 [deg]F dry-bulb temperature and a maximum of 60 
[deg]F wet-bulb temperature).
    Issue 10: DOE requests comment on the proposal to adopt provisions 
from AHRI 340/360-2022 such that testing would be conducted within 
tolerance of the AHRI 340/360-2022 minimum ESP requirements, and 
efficiency ratings would include the fan power measured to overcome the 
tested ESP.
    Issue 11: DOE requests comment on the proposed adoption of 
provisions from AHRI 340/360-2022 for setting airflow and ESP for WSHP 
testing.
    Issue 12: DOE requests comment on its proposed instructions for 
setting airflow and ESP for ducted WSHP units with discrete-step fans.
    Issue 13: DOE requests comment on its proposal for setting airflow 
and ESP for non-ducted WSHP units.
    Issue 14: DOE requests comment on its proposed approach to adopt 
the provisions in AHRI 340/360-2022 and ANSI/ASHRAE 37-2009 regarding 
primary and secondary capacity measurements.
    Issue 15: DOE requests comment on the proposal to adopt the cyclic 
degradation equation specified in Section 6.2.3.2 of AHRI 340/360-2022 
for WSHPs, which assumes continuous indoor fan operation when the 
compressor cycles off.
    Issue 16: DOE requests comment on the proposed provisions to 
account for pump power to overcome both internal pressure drop and a 
representative level of liquid ESP for WSHPs with and without integral 
pumps. DOE specifically requests comment on the representativeness of 
20 ft of water column as the liquid ESP for WSHPs.
    Issue 17: DOE requests comment on the proposed requirements for 
using water or a brine of 15-percent solution by mass of sodium 
chloride as the test liquid. DOE also requests comment on the 
representativeness and test burden associated with permitting the use 
of different liquids for different tests.
    Issue 18: DOE requests comments on the proposal to utilize the 
thermodynamic properties specified in ANSI/ASHRAE 37-2009 through DOE's 
proposed incorporation by reference of AHRI 340/360-2022.
    Issue 19: DOE requests comment on its proposal to adopt the AHRI 
340/360-2022 approach for setting liquid flow rate for the full-load 
cooling test, namely by specifying inlet and outlet liquid temperature 
conditions rather than using a manufacturer-specified flow rate.
    Issue 20: DOE requests feedback on its proposals to use 
manufacturer-specified part-load liquid flow rates for part-load tests, 
that the part-load flow rate be no higher than the full-load flow rate, 
and to use the full-load liquid flow rate if no part-load liquid flow 
rate is specified.
    Issue 21: DOE requests comment on its proposal to use the liquid 
flow rate determined from the full-load cooling test for all heating 
tests.
    Issue 22: DOE requests comment on its proposal to specify an 
operating tolerance of 2 percent and a condition tolerance of 1 percent 
for liquid flow rate in all tests with a target liquid flow rate.
    Issue 23: DOE requests comments on the proposal to adopt the 
provisions for line loss adjustments included in Sections 7.6.7.1 and 
7.3.3.4 of ANSI/ASHRAE 37-2009 through incorporation by reference of 
AHRI 340/360-2022.
    Issue 24: DOE requests comments on the proposal to adopt the 
calculation of discharge coefficients and air measurement apparatus 
requirements of ANSI/ASHRAE 37-2009.
    Issue 25: DOE requests comments on the proposal to adopt the air 
condition measurement provisions in Appendix C of AHRI 340/360-2022.
    Issue 26: DOE requests comments on the proposal to adopt the duct 
loss provisions in Section 7.3.3.3 of ASHRAE 37-2009.
    Issue 27: DOE requests comments on the proposal to adopt the 
refrigerant charging requirements in Section 5.8 of AHRI 340/360-2022.
    Issue 28: DOE requests comments on the proposal to adopt the 
voltage provisions in Section 6.1.3.1 of AHRI 340/360-2022.
    Issue 29: DOE seeks comment on its proposals regarding specific 
components in 10 CFR 429.43, 10 CFR 429.134, and 10 CFR part 431, 
subpart F, appendix C1.
    Issue 30: DOE requests comment on its proposal to adopt the methods 
for comparing relative efficiency of standard and non-standard indoor 
fan motors and integrated fan and motor combinations specified in 
Section D4 of AHRI 340/360-2022 in the proposed test procedure in 10 
CFR part 431, subpart F, appendix C1, as well as in provisions for 
determination of represented values in 10 CFR 429.43(a) and provisions 
for DOE assessment and enforcement testing in 10 CFR 429.134.
    Issue 31: DOE requests comment on its proposals related to 
represented values and verification testing of cooling capacity for 
WSHPs.
    Issue 32: DOE requests comment on its understanding of the impact 
of the test procedure proposals in this NOPR. DOE also seeks specific 
feedback on the estimated costs to rate WSHP models with an AEDM.
    Issue 33: DOE requests comment on the number of small OEMs DOE 
identified. DOE also seeks comment on the Department's estimates of 
potential costs these small manufacturers may incur as a result of its 
proposed amendments to the WSHP test procedure.

VI. Approval of the Office of the Secretary

    The Secretary of Energy has approved publication of this notice of 
proposed rulemaking and request for comment.

[[Page 53348]]

List of Subjects

10 CFR Part 429

    Administrative practice and procedure, Confidential business 
information, Energy conservation, Household appliances, Imports, 
Incorporation by reference, Intergovernmental relations, Reporting and 
recordkeeping requirements, Small businesses.

10 CFR Part 431

    Administrative practice and procedure, Confidential business 
information, Energy conservation, Household appliances, Imports, 
Incorporation by reference, Intergovernmental relations, Laboratories, 
Reporting and recordkeeping requirements, Small businesses.

Signing Authority

    This document of the Department of Energy was signed on August 3, 
2022, by Kelly J. Speakes-Backman, Principal Deputy Assistant for 
Energy Efficiency and Renewable Energy, 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 August 4, 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 amended on July 27, 2022 (published at 87 FR 45164), 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.  429.4 by:
0
a. Revising paragraph (a);
0
b. Redesignating paragraph (c)(2) as paragraph (c)(3); and
0
c. Adding new paragraph (c)(2).

    The revision and addition read as follows.


Sec.  429.4   Materials incorporated by reference.

    (a) Certain material is incorporated by reference into this part 
with the 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, the U.S. Department of Energy 
(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 the 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], https://www.energy.gov/eere/buildings/appliance-and-equipment-standards-program. 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.
* * * * *
    (c) * * *
    (2) AHRI Standard 340/360-2022 (I-P) (``AHRI 340/360-2022''), 2022 
Standard for Performance Rating of Commercial and Industrial Unitary 
Air-conditioning and Heat Pump Equipment, AHRI-approved January 26, 
2022; IBR approved for Sec.  429.43.
* * * * *
0
3. Amend Sec.  429.43 by adding paragraph (a)(3)(ii) to read as 
follows:


Sec.  429.43   Commercial heating, ventilating, air conditioning (HVAC) 
equipment.

    (a) * * *
    (3) * * *
    (ii) Water-Source Heat Pumps. When certifying to standards in terms 
of IEER, the following provisions apply.
    (A) Individual model selection:
    (1) Representations for a basic model must be based on the least 
efficient individual model(s) distributed in commerce among all 
otherwise comparable model groups comprising the basic model, except as 
provided in paragraph (a)(3)(ii)(A)(2) of this section for individual 
models that include components listed in table 1 to paragraph 
(a)(3)(ii)(A) of this section. For the purpose of this paragraph 
(a)(3)(ii)(A)(1), ``otherwise comparable model group'' means a group of 
individual models distributed in commerce within the basic model that 
do not differ in components that affect energy consumption as measured 
according to the applicable test procedure specified at 10 CFR 431.96 
other than those listed in table 1 to paragraph (a)(3)(ii)(A) of this 
section. An otherwise comparable model group may include individual 
models distributed in commerce with any combination of the components 
listed in table 1 (or none of the components listed in table 1). An 
otherwise comparable model group may consist of only one individual 
model.
    (2) For a basic model that includes individual models distributed 
in commerce with components listed in table 1 to paragraph 
(a)(3)(ii)(A) of this section, the requirements for determining 
representations apply only to the individual model(s) of a specific 
otherwise comparable model group distributed in commerce with the least 
number (which could be zero) of components listed in table 1 included 
in individual models of the group. Testing under this paragraph shall 
be consistent with any component-specific test provisions specified in 
section 7 of appendix C1 to subpart F of part 431.

                       Table 2 to Paragraph (a)(3)
------------------------------------------------------------------------
          Component                           Description
------------------------------------------------------------------------
Desiccant Dehumidification     An assembly that reduces the moisture
 Components.                    content of the supply air through
                                moisture transfer with solid or liquid
                                desiccants.
Air Economizers..............  An automatic system that enables a
                                cooling system to supply outdoor air to
                                reduce or eliminate the need for
                                mechanical cooling during mild or cold
                                weather.

[[Page 53349]]

 
Ventilation Energy Recovery    An assembly that preconditions outdoor
 System (VERS).                 air entering the equipment through
                                direct or indirect thermal and/or
                                moisture exchange with the exhaust air,
                                which is defined as the building air
                                being exhausted to the outside from the
                                equipment.
Steam/Hydronic Heat Coils....  Coils used to provide supplemental
                                heating.
Refrigerant Reheat...........  A heat exchanger located downstream of
                                the indoor coil that heats the supply
                                air during cooling operation using high-
                                pressure refrigerant in order to
                                increase the ratio of moisture removal
                                to cooling capacity provided by the
                                equipment.
Fire/Smoke/Isolation Dampers.  A damper assembly including means to open
                                and close the damper mounted at the
                                supply or return duct opening of the
                                equipment.
Powered Exhaust/Powered        A powered exhaust fan is a fan that
 Return Air Fans.               transfers directly to the outside a
                                portion of the building air that is
                                returning to the unit, rather than
                                allowing it to recirculate to the indoor
                                coil and back to the building. A powered
                                return fan is a fan that draws building
                                air into the equipment.
Sound Traps/Sound Attenuators  An assembly of structures through which
                                the supply air passes before leaving the
                                equipment or through which the return
                                air from the building passes immediately
                                after entering the equipment for which
                                the sound insertion loss is at least 6
                                dB for the 125 Hz octave band frequency
                                range.
Process Heat Recovery/Reclaim  A heat exchanger located inside the unit
 Coils/Thermal Storage.         that conditions the equipment's supply
                                air using energy transferred from an
                                external source using a vapor, gas, or
                                liquid.
Indirect/Direct Evaporative    Water is used indirectly or directly to
 Cooling of Ventilation Air.    cool ventilation air. In a direct system
                                the water is introduced directly into
                                the ventilation air and in an indirect
                                system the water is evaporated in
                                secondary air stream and the heat is
                                removed through a heat exchanger.
Condenser Pumps/Valves/        Additional components in the water
 Fittings.                      circuit for water control or filtering.
Condenser Water Reheat.......  A heat exchanger located downstream of
                                the indoor coil that heats the supply
                                air during cooling operation using water
                                from the condenser coil in order to
                                increase the ratio of moisture removal
                                to cooling capacity provided by the
                                equipment.
Grill Options................  Special grills used to direct airflow in
                                unique applications (such as up and away
                                from a rear wall).
Non-Standard Indoor Fan        The standard indoor fan motor is the
 Motors.                        motor specified in the manufacturer's
                                installation instructions for testing
                                and shall be distributed in commerce as
                                part of a particular model. A non-
                                standard motor is an indoor fan motor
                                that is not the standard indoor fan
                                motor and that is distributed in
                                commerce as part of an individual model
                                within the same basic model.
                               For a non-standard indoor fan motor(s) to
                                be considered a specific component for a
                                basic model (and thus subject to the
                                provisions of (a)(3)(ii)(A)(2) of this
                                section), the following provisions must
                                be met:
                               Non-standard indoor fan motor(s) must
                                meet the minimum allowable efficiency
                                determined per Section D4.1 of AHRI 340/
                                360-2022 (incorporated by reference, see
                                Sec.   429.4) (i.e., for non-standard
                                indoor fan motors) or per Section D4.2
                                of AHRI 340/360-2022 for non-standard
                                indoor integrated fan and motor
                                combinations). If the standard indoor
                                fan motor can vary fan speed through
                                control system adjustment of motor
                                speed, all non-standard indoor fan
                                motors must also allow speed control
                                (including with the use of a variable-
                                frequency drive).
------------------------------------------------------------------------

    (B) The represented value of cooling capacity must be between 95 
percent and 100 percent of the mean of the cooling capacities measured 
for the units in the sample selected as described in paragraph 
(a)(1)(ii) of this section, or between 95 percent and 100 percent of 
the cooling capacity output simulated by the AEDM as described in 
paragraph (a)(2) of this section.
* * * * *
0
4. Amend Sec.  429.134 by adding paragraph (t) to read as follows:


Sec.  429.134   Product-specific enforcement provisions.

* * * * *
    (t) Water-Source Heat Pumps. The following provisions apply for 
assessment and enforcement testing of models subject to standards in 
terms of IEER.
    (1) Verification of Cooling Capacity. The cooling capacity of each 
tested unit of the basic model will be measured pursuant to the test 
requirements of appendix C1 to subpart F of 10 CFR part 431. The mean 
of the measurements will be used to determine the applicable standards 
for purposes of compliance.
    (2) Specific Components. If a basic model includes individual 
models with components listed at table 1 to Sec.  429.43(a)(3)(ii)(A) 
and DOE is not able to obtain an individual model with the least number 
(which could be zero) of those components within an otherwise 
comparable model group (as defined in Sec.  429.43(a)(3)(ii)(A)(1)), 
DOE may test any individual model within the otherwise comparable model 
group.
    (3) Approach for Determining IEER. If the manufacturer specifies 
that they used ``Option 2'' as described in section 5.1.2 of appendix 
C1 (i.e., using interpolation and extrapolation to determine 
performance at IEER entering water temperatures), DOE will assess 
compliance for the basic model based on testing in accordance with 
``Option 2'' as described in section 5.1.2 of appendix C1. If the 
manufacturer does not specify that they used ``Option 2'' as described 
in section 5.1.2 of appendix C1, DOE will assess compliance for IEER 
for the basic model based on testing in accordance ``Option 1'' as 
described in section 5.1.1 of appendix C1.

PART 431--ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND 
INDUSTRIAL EQUIPMENT

0
5. 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
6. Amend Sec.  431.92 by revising the definition for ``Water-source 
heat pump'' to read as follows:

[[Page 53350]]

Sec.  431.92   Definitions concerning commercial air conditioners and 
heat pumps.

* * * * *
    Water-source heat pump means commercial package air-conditioning 
and heating equipment that is a single-phase or three-phase reverse-
cycle heat pump that uses a circulating water loop as the heat source 
for heating and as the heat sink for cooling. The main components are a 
compressor, refrigerant-to-water heat exchanger, refrigerant-to-air 
heat exchanger, refrigerant expansion devices, refrigerant reversing 
valve, and indoor fan (except that coil-only units do not include an 
indoor fan). Such equipment includes, but is not limited to, water-to-
air water-loop heat pumps.
0
7. Amend Sec.  431.95 by:
0
a. Redesignating paragraphs (b)(4) through (b)(7) as paragraphs (b)(5) 
through (b)(8);
0
b. Adding new paragraph (b)(4);
0
c. Revising paragraphs (c)(2);
0
d. Redesignating paragraphs (c)(3) through (7) as paragraphs (c)(5) 
through (8);
0
e. Adding new paragraph (c)(3);
0
f. In the introductory text to (d), remove the text ``http://''; and
0
g. Revise paragraph (d)(1).

    The additions and revisions read as follows:


Sec.  431.95  Materials incorporated by reference.

* * * * *
    (b) * * *
    (4) AHRI Standard 340/360-2022 (I-P) (``AHRI 340/360-2022''), 2022 
Standard for Performance Rating of Commercial and Industrial Unitary 
Air-conditioning and Heat Pump Equipment, AHRI-approved January 26, 
2022: IBR approved for appendix C1 to this subpart.
* * * * *
    (c) * * *
    (2) ANSI/ASHRAE Standard 37-2009 (``ANSI/ASHRAE 37-2009''), Methods 
of Testing for Rating Electrically Driven Unitary Air-Conditioning and 
Heat Pump Equipment, ASHRAE approved June 24, 2009; IBR approved -for 
Sec.  431.96 and appendices A, B, and C1 to this subpart.
    (3) ASHRAE errata sheet to ANSI/ASHRAE Standard 37-2009 (``ASHRAE 
37-2009 TE''), issued March 27, 2019; IBR approved -for appendix C1 to 
this subpart.
* * * * *
    (d) * * *
    (1) ISO Standard 13256-1 (``ISO Standard 13256-1:1998''), ``Water-
source heat pumps--Testing and rating for performance--Part 1: Water-
to-air and brine-to-air heat pumps,'' approved 1998, IBR approved for 
appendix C to this subpart.
* * * * *
0
8. Amend Sec.  431.96 by revising paragraph (b)(1) and table 1 to 
paragraph (b) to read as follows:


Sec.  431.96   Uniform test method for the measurement of energy 
efficiency of commercial air conditioners and heat pumps.

* * * * *
    (b) * * * (1) Determine the energy efficiency and capacity of each 
category of covered equipment by conducting the test procedure(s) 
listed in table 1 to this paragraph (b) along with any additional 
testing provisions set forth in paragraphs (c) through (g) of this 
section and appendices A through C1 to this subpart, that apply to the 
energy efficiency descriptor for that equipment, category, and cooling 
capacity. The omitted sections of the test procedures listed in table 1 
to this paragraph (b) must not be used.
* * * * *

                                Table 1 to Paragraph (b)--Test Procedures for Commercial Air Conditioners and Heat Pumps
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                      Additional test
                                                               Cooling capacity or                                Use tests,        procedure provisions
           Equipment type                   Category            moisture removal       Energy efficiency       conditions, and      as indicated in the
                                                                  capacity \2\             descriptor         procedures \1\ in     listed paragraphs of
                                                                                                                                        this section
--------------------------------------------------------------------------------------------------------------------------------------------------------
Small Commercial Package Air-        Air-Cooled, 3-Phase,    <65,000 Btu/h.........  SEER and HSPF........  AHRI 210/240-2008      Paragraphs (c) and
 Conditioning and Heating Equipment.  AC and HP.                                                             (omit section 6.5).    (e).
                                     Air-Cooled AC and HP..  >=65,000 Btu/h and      EER, IEER, and COP...  Appendix A to this     None.
                                                              <135,000 Btu/h.                                subpart.
                                     Water-Cooled and        <65,000 Btu/h.........  EER..................  AHRI 210/240-2008      Paragraphs (c) and
                                      Evaporatively-Cooled                                                   (omit section 6.5).    (e).
                                      AC.
                                                             >=65,000 Btu/h and      EER..................  AHRI 340/360-2007      Paragraphs (c) and
                                                              <135,000 Btu/h.                                (omit section 6.3).    (e).
                                     Water-Source HP.......  <135,000 Btu/h........  EER and COP..........  Appendix C to this     None.
                                                                                                             subpart\3\.
                                     Water-Source HP.......  <135,000 Btu/h........  IEER and COP.........  Appendix C1 to this    None.
                                                                                                             subpart\3\.
Large Commercial Package Air-        Air-Cooled AC and HP..  >=135,000 Btu/h and     EER, IEER and COP....  Appendix A to this     None.
 Conditioning and Heating Equipment.                          <240,000 Btu/h.                                subpart.
                                     Water-Cooled and        >=135,000 Btu/h and     EER..................  AHRI 340/360-2007      Paragraphs (c) and
                                      Evaporatively-Cooled    <240,000 Btu/h.                                (omit section 6.3).    (e).
                                      AC.
                                     Water-Source HP.......  >=135,000 Btu/h and     EER and COP..........  Appendix C to this     None.
                                                              <240,000 Btu/h.                                subpart\3\.
                                     Water-Source HP.......  >=135,000 Btu/h and     IEER and COP.........  Appendix C1 to this    None.
                                                              <240,000 Btu/h.                                subpart\3\.
Very Large Commercial Package Air-   Air-Cooled AC and HP..  >=240,000 Btu/h and     EER, IEER and COP....  Appendix A to this     None.
 Conditioning and Heating Equipment.                          <760,000 Btu/h.                                subpart.

[[Page 53351]]

 
                                     Water-Cooled and        >=240,000 Btu/h and     EER..................  AHRI 340/360-2007      Paragraphs (c) and
                                      Evaporatively-Cooled    <760,000 Btu/h.                                (omit section 6.3).    (e).
                                      AC.
                                     Water-Source HP.......  >=240,000 Btu/h and     EER and COP..........  Appendix C to this     None.
                                                              <760,000 Btu/h.                                subpart\3\.
                                     Water-Source HP.......  >=240,000 Btu/h and     IEER and COP.........  Appendix C1 to this    None.
                                                              <760,000 Btu/h.                                subpart\3\.
Packaged Terminal Air Conditioners   AC and HP.............  <760,000 Btu/h........  EER and COP..........  Paragraph (g) of this  Paragraphs (c), (e),
 and Heat Pumps.                                                                                             section.               and (g).
Computer Room Air Conditioners.....  AC....................  <65,000 Btu/h.........  SCOP.................  ASHRAE 127-2007 (omit  Paragraphs (c) and
                                                                                                             section 5.11).         (e).
                                                             >=65,000 Btu/h and      SCOP.................  ASHRAE 127-2007 (omit  Paragraphs (c) and
                                                              <760,000 Btu/h.                                section 5.11).         (e).
Variable Refrigerant Flow Multi-     AC....................  <65,000 Btu/h (3-       SEER.................  AHRI 1230-2010 (omit   Paragraphs (c), (d),
 split Systems.                                               phase).                                        sections 5.1.2 and     (e), and (f).
                                                                                                             6.6).
                                                             >=65,000 Btu/h and      EER..................  AHRI 1230-2010 (omit   Paragraphs (c), (d),
                                                              <760,000 Btu/h.                                sections 5.1.2 and     (e), and (f).
                                                                                                             6.6).
Variable Refrigerant Flow Multi-     HP....................  <65,000 Btu/h (3-       SEER and HSPF........  AHRI 1230-2010 (omit   Paragraphs (c), (d),
 split Systems, Air-cooled.                                   phase).                                        sections 5.1.2 and     (e), and (f).
                                                                                                             6.6).
                                                             >=65,000 Btu/h and      EER and COP..........  AHRI 1230-2010 (omit   Paragraphs (c), (d),
                                                              <760,000 Btu/h.                                sections 5.1.2 and     (e), and (f).
                                                                                                             6.6).
Variable Refrigerant Flow Multi-     HP....................  <760,000 Btu/h........  EER and COP..........  AHRI 1230-2010 (omit   Paragraphs (c), (d),
 split Systems, Water-source.                                                                                sections 5.1.2 and     (e), and (f).
                                                                                                             6.6).
Single Package Vertical Air          AC and HP.............  <760,000 Btu/h........  EER and COP..........  AHRI 390-2003 (omit    Paragraphs (c) and
 Conditioners and Single Package                                                                             section 6.4).          (e).
 Vertical Heat Pumps.
Direct Expansion-Dedicated Outdoor   All...................  <324 lbs. of moisture   ISMRE2 and ISCOP2....  Appendix B to this     None.
 Air Systems.                                                 removal/hr.                                    subpart.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Incorporated by reference; see Sec.   431.95.
\2\ Moisture removal capacity is determined according to appendix B of this subpart.
\3\ For equipment with multiple appendices listed in this table 1, consult the notes at the beginning of those appendices to determine the applicable
  appendix to use for testing.

* * * * *
0
9. Add appendix C to subpart F of part 431 to read as follows:

Appendix C to Subpart F of Part 431--Uniform Test Method for Measuring 
the Energy Consumption of Water-Source Heat Pumps

    Note: Manufacturers must use the results of testing under this 
appendix to determine compliance with the relevant standard at Sec.  
431.97 as that standard appeared in the January 1, 2022 edition of 
10 CFR parts 200-499. Specifically, representations must be based on 
testing according to either this appendix or 10 CFR 431.96 as it 
appeared in the 10 CFR parts 200-499 edition revised as of January 
1, 2022.
    Starting on [Date 360 days after publication of the final rule 
in the Federal Register], voluntary representations with respect to 
the energy efficiency ratio (EER) of water-source heat pumps with 
cooling capacity greater than or equal to 135,000 Btu/h and less 
than 760,000 Btu/h must be based on testing according to appendix C 
of this subpart. Manufacturers may also use appendix C to make 
voluntary representations with respect to EER prior to [Date 360 
days after publication of the final rule in the Federal Register].
    Starting on [Date 360 days after publication of the final rule 
in the Federal Register], voluntary representations with respect to 
the integrated energy efficiency ratio (IEER) of water-source heat 
pumps must be based on testing according to appendix C1 of this 
subpart. Manufacturers may also use appendix C1 to make voluntary 
representations with respect to IEER prior to [Date 360 days after 
publication of the final rule in the Federal Register].
    Starting on the compliance date for any amended energy 
conservation standards for water-source heat pumps based on IEER, 
any representations, including compliance certifications, made with 
respect to the energy use or energy efficiency of water-source heat 
pumps must be based on testing according to appendix C1 of this 
subpart.
    Manufacturers may also to certify compliance with any amended 
energy conservation standards for water-source heat pumps based on 
IEER prior to the applicable compliance date for those standards, 
and those compliance certifications must be based on testing 
according to appendix C1 of this subpart.


    1. Incorporation by Reference.
    DOE incorporated by reference in Sec.  431.95 the entire 
standard for ISO 13256-1:1998. To the extent there is a conflict 
between the terms or provisions of a referenced industry standard 
and this appendix, the appendix provisions control.
    2. General.
    Determine the energy efficiency ratio (EER) and coefficient of 
performance (COP) in accordance with ISO 13256-1:1998.
    Section 3 of this appendix provides additional instructions for 
determining EER and COP.

[[Page 53352]]

    3. Additional Provisions for Equipment Set-up. The only 
additional specifications that may be used in setting up the basic 
model for testing are those set forth in the installation and 
operation manual shipped with the unit. Each unit should be set up 
for test in accordance with the manufacturer installation and 
operation manuals. Sections 3.1 through 3.2 of this appendix provide 
specifications for addressing key information typically found in the 
installation and operation manuals.
    3.1. If a manufacturer specifies a range of superheat, sub-
cooling, and/or refrigerant pressure in its installation and 
operation manual for a given basic model, any value(s) within that 
range may be used to determine refrigerant charge or mass of 
refrigerant, unless the manufacturer clearly specifies a rating 
value in its installation and operation manual, in which case the 
specified rating value must be used.
    3.2. The airflow rate used for testing must be that set forth in 
the installation and operation manuals being shipped to the 
commercial customer with the basic model and clearly identified as 
that used to generate the DOE performance ratings. If a rated 
airflow value for testing is not clearly identified, a value of 400 
standard cubic feet per minute (scfm) per ton must be used.

0
10. Add appendix C1 to subpart F of part 431 to read as follows:

Appendix C1 to Subpart F of Part 431--Uniform Test Method for Measuring 
the Energy Consumption of Water-Source Heat Pumps

    Note: Prior to the compliance date of amended standards for 
water-source heat pumps that rely on integrated energy efficiency 
ratio (IEER) published after January 1, 2022, representations with 
respect to the energy use or energy efficiency of water-source heat 
pumps, including compliance certifications, must be based on energy 
efficiency ratio (EER) testing according to this appendix C of this 
subpart.
    Starting on [Date 360 days after publication of the final rule 
in the Federal Register], voluntary representations with respect to 
the IEER of water-source heat pumps must be based on testing 
according to this appendix. Manufacturers may also use this appendix 
C1 to make voluntary representations with respect to IEER prior to 
[Date 360 days after publication of the final rule in the Federal 
Register].
    Starting on the compliance date for any amended energy 
conservation standards for water-source heat pumps based on IEER, 
any representations, including compliance certifications, made with 
respect to the energy use or energy efficiency of water-source heat 
pumps must be based on testing according to this appendix.
    Manufacturers may also certify compliance with any amended 
energy conservation standards for water-source heat pumps based on 
IEER prior to the applicable compliance date for those standards, 
and those compliance certifications must be based on testing 
according to this appendix.


    1. Incorporation by Reference.
    DOE incorporated by reference in Sec.  431.95 the entire 
standard for AHRI 340/360-2022 and ANSI/ASHRAE 37-2009 (which 
includes ASHRAE 37-2009 TE). However, only certain enumerated 
provisions of AHRI 340/360-2022 are applicable, while the enumerated 
provisions of ANSI/ASHRAE 37-2009 are inapplicable as set out in 
this section 1. To the extent there is a conflict between the terms 
or provisions of a referenced industry standard and this appendix, 
the appendix provisions control, followed by AHRI 340/360-2022, 
followed by ANSI/ASHRAE 37-2009.
    1.1. Applicable provisions.
    1.1.1. AHRI 340/360-2022:
    (a) Section 3 Definitions, except the following subsections: 3.2 
(Basic Model), 3.4 (Commercial and Industrial Unitary Air-
conditioning Equipment), 3.5 (Commercial and Industrial Unitary Heat 
Pump), 3.7 (Double-duct System), 3.8 (Energy Efficiency Ratio), 3.12 
(Heating Coefficient of Performance), 3.14 (Integrated Energy 
Efficiency Ratio), 3.15 (Indoor Single Package Air-conditioners), 
3.17 (Makeup Water), 3.23 (Published Rating), 3.26 (Single Package 
Air-Conditioners), 3.27 (Single Package Heat Pumps), 3.29 (Split 
System Air-conditioners), 3.30 (Split System Heat Pump), and 3.36 
(Year Round Single Package Air-conditioners);
    (b) Section 5 Test Requirements;
    (c) Section 6 Rating Requirements, except the following 
subsections: 6.1.1.7, 6.1.2.1 (Values of Standard Capacity Ratings), 
6.1.3.4.5, 6.1.3.5.4 (Heating Test for MZVAV Units), 6.1.3.5.5 
(Part-Load Cooling Tests for MZVAV Units), 6.5 (Ratings), 6.6 
(Uncertainty), and 6.7 (Verification Testing);
    (d) Appendix A References--Normative;
    (e) Appendix C Indoor and Outdoor Air Condition Measurement--
Normative; and
    (f) Appendix E Method of Testing Unitary Air Conditioning 
Products--Normative.
    1.1.2. [Reserved]
    1.2. Inapplicable provisions.
    1.2.1. ANSI/ASHRAE 37-2009
    (a) Section 1 Purpose, as specified in section 2.2 of this 
appendix;
    (b) Section 2 Scope, as specified in section 2.2 of this 
appendix; and
    (c) Section 4 Classification, as specified in section 2.2 of 
this appendix.
    1.2.2. [Reserved]
    2. General.
    Determine integrated energy efficiency ratio (IEER) and heating 
coefficient of performance (COP) in accordance with AHRI 340/360-
2022 and ANSI/ASHRAE 37-2009; however, only the following enumerated 
provisions of AHRI 340/360-2022 are applicable, as set forth in 
section 2.1 of this appendix. All sections of ANSI/ASHRAE 37-2009 
are applicable with the exception of provisions listed in section 
2.2 of this appendix.
    Sections 2 through 7 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 
340/360-2022, followed by ANSI/ASHRAE 37-2009. 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.
    2.1. Test requirements and test conditions specified for water-
cooled equipment in AHRI 340/360-2022 and ANSI/ASHRAE 37-2009 are 
applicable to water-source heat pumps.
    2.2. For units without integral fans, use test requirements and 
test conditions specified as ``coil-only'' in AHRI 340/360-2022 and 
ANSI/ASHRAE 37-2009.
    2.3. When using the Outdoor Liquid Coil Method, when calculating 
the total heating capacity, use the ASHRAE 37-2009 TE heating 
capacity formula for section 7.6.5.1 of ANSI/ASHRAE 37-2009.
    3. Airflow and External Static Pressure.
    3.1. Non-Ducted Units.
    These provisions apply to units that are not configured 
exclusively for delivery of conditioned air to the indoor space 
without a duct(s).
    3.1.1. Target Airflow and ESP.
    Determine the target airflow in accordance with Section 6.1.3.4 
of AHRI 340/360-2022, using an external static pressure (ESP) of 
0.00 in H2O in place of the ESP specified in Section 
6.1.3.3 of AHRI 340/360-2022. Exclude Section 6.1.3.3 of AHRI 340/
360-2022.
    3.1.2. Airflow and ESP Tolerances and Set-Up.
    Exclude Section 6.1.3.5 of AHRI 340/360-2022, and use the 
provisions in this section for indoor external static pressure and 
airflow set-up. For each test, set indoor airflow while operating 
the unit at the rating conditions specified for the test. After 
setting the airflow, no adjustments may be made to the fan control 
settings during the test.
    3.1.2.1. Tolerances.
    All tolerances for airflow and ESP specified in section 3.1.2 of 
this appendix for setting airflow and ESP are condition tolerances 
that apply for each test. Specifically, the average value of a 
parameter measured over the course of the test shall vary from the 
target value by no more than the condition tolerance. Operating 
tolerances for ESP and nozzle pressure drop are specified in Table 
11 of AHRI 340/360-2022.
    3.1.2.2. Use the manufacturer-specified fan control settings for 
all tests for which they are provided. Use the full-load cooling fan 
control settings specified by the manufacturer for all tests for 
which fan control settings are not specified. If there are no 
manufacturer-specified fan control settings for any tests, use the 
as-shipped fan control settings for all tests.
    3.1.2.3. For all tests, conduct the test at 0.00 in H2O with a 
condition tolerance of -0/+0.05 in H2O.
    3.1.2.4. For heating tests and part-load cooling tests for which 
there is no manufacturer-specified airflow and the cooling full-load 
rated indoor airflow is not used as the airflow for the test because 
there are manufacturer-specified fan control settings or other 
instructions used to obtain steady-state operation for the test, per 
the provisions of Section 6.1.3.4 of AHRI 340/360-2022, there is no 
airflow condition

[[Page 53353]]

tolerance for that test. For all other tests, the airflow condition 
tolerance is 3% of the target airflow determined in 
section 3.1.1 of this appendix.
    3.1.2.5. If both the ESP and airflow cannot be simultaneously 
maintained within tolerance for any test, maintain the ESP within 
the required tolerance and use an airflow as close to the 
manufacturer-specified value as possible. The average airflow rate 
measured over the course of the test shall be within 3% 
of the airflow rate measured after setting airflow for the test.
    3.1.2.6. If section 3.1.2.5 of this appendix is used to set the 
full-load cooling airflow, use the measured full-load cooling 
airflow as the target airflow for all subsequent tests that call for 
the full-load cooling airflow.
    3.2. Ducted Units.
    These provisions apply to units that are configured for delivery 
of conditioned air to the indoor space with a duct(s).
    3.2.1. For units with continuously variable-speed fans, set 
airflow and external static pressure in accordance with Sections 
6.1.3.3, 6.1.3.4, and 6.1.3.5 of AHRI 340/360-2022.
    3.2.2. For units without continuously variable-speed fans, set 
airflow and external static pressure in accordance with Sections 
6.1.3.3., 6.1.3.4., and 6.1.3.5 of AHRI 340/360-2022, except use 
section 3.2.2.1 of this appendix in place of Sections 6.1.3.5.2.4 
and 6.1.3.5.3.2.3 of AHRI 340/360-2022.
    3.2.2.1. For two adjacent fan control settings, if both airflow 
and ESP tolerances cannot be met, (e.g., decreasing fan speed when 
the ESP or airflow are too high causes the ESP or airflow to be 
lower than the tolerance range, and increasing fan speed when the 
ESP or airflow are too low causes the ESP or airflow to be higher 
than the tolerance range), operate at the lower fan control setting, 
adjust the airflow measuring apparatus to maintain the ESP within -
0.00/+0.05 in H2O of the requirement determined in Section 6.1.3.3 
of AHRI 340/360-2022, and maintain the airflow at a rate no lower 
than 90% of the airflow rate determined in Section 6.1.3.3 of AHRI 
340/360-2022. If increasing ESP to within -0.00/+0.05 in H2O of the 
requirement determined in Section 6.1.3.3 of AHRI 340/360-2022 
reduces airflow of the unit under test to less than 90% of the 
manufacturer-specified airflow, then the next higher fan control 
setting shall be utilized to obtain rated airflow. Using this higher 
fan control setting, maintain airflow within tolerance and maintain 
the ESP as close as possible to the value determined in Section 
6.1.3.3 of AHRI 340/360-2022.
    4. Test Liquid, Liquid ESP, and Pump Effect.
    4.1. The test liquid for all tests other than the optional HFL3 
low-temperature heating test specified in Table 9 of this appendix 
must be water unless the manufacturer specifies to use a brine of 
15% solution by mass of sodium chloride in water. The test liquid 
for the optional HFL3 low-temperature heating test must be a brine 
of 15% solution by mass of sodium chloride in water.
    4.2. For units with an integral pump, set the external static 
pressure to 20 ft of water column, with a -0/+1 ft condition 
tolerance and a 1 ft operating tolerance.
    4.3. For units without an integral pump, when calculating EER 
and COP, an addition for the pump effect, PE, must be added to the 
unit's measured power and determined using Equation 1 of this 
appendix. Use this adder in place of Section 6.1.1.7 of AHRI 340/
360-2022.
[GRAPHIC] [TIFF OMITTED] TP30AU22.038

Where:

PE = Pump effect, W
WF = Liquid flow rate, gpm
PPB = Basic Pumping Penalty (Table 1), W/(gpm*psi)
[Delta]P = Pressure drop measured across liquid heat exchanger, psi
C = 25 W/gpm based on 20 ft external head

     Table 1--Basic Pumping Penalty (PPB) vs. Liquid Flow Rate (WF)
------------------------------------------------------------------------
                                                           Basic pumping
                                                          penalty (PPB),
               Liquid flow rate (WF), gpm                   W/(gpm*psi)
 
------------------------------------------------------------------------
1.0-4.0.................................................            5.00
4.1-7.9.................................................            3.88
8.0-11.9................................................            2.69
12.0-15.9...............................................            2.32
16.0-19.9...............................................            2.14
20.0 and above..........................................            2.02
------------------------------------------------------------------------

    4.4. Condenser section power (PCD) in Equation 4 of AHRI 340/
360-2022 must be determined as follows (instead of determining via 
Section 6.2.3.2 of AHRI 340/360-2022):
    4.4.1. For units with an integral pump, PCD is equal to the 
measured pump power.
    4.4.2. For units without an integral pump, PCD is equal to the 
pump effect determined per section 4.3 of this appendix.
    5. Cooling Rating.
    5.1. Methods for Determining IEER.
    Determine the integrated energy efficiency ratio (IEER) using 
one of two options, as described in the following sections 5.1.1 and 
5.1.2 of this appendix.
    5.1.1. Option 1: Determine IEER in Accordance with Section 6.2 
of AHRI 340/360-2022.
    Test at the four IEER inlet water temperatures specified for 
water-cooled equipment in Table 9 of AHRI 340/36-2022, and perform 
all tests according to sections 2 through 4 and section 7 of this 
appendix.
    Except as adjusted for operation at low condenser temperatures 
per Section E7 of AHRI 340/360-2022, for part-load cooling tests, 
use manufacturer-specified liquid flow rates. For all part-load 
cooling tests, the liquid flow rate shall not exceed the liquid flow 
rate used for the cooling full-load tests. If the manufacturer-
specified part-load cooling liquid flow rate is higher than the 
liquid flow rate used for the cooling full-load tests, use the 
liquid flow rate used for the cooling full-load tests. If no 
manufacturer-specified value for part-load cooling liquid flow rate 
is provided, use the liquid flow rate used for the cooling full-load 
tests. The condition tolerance on liquid flow rate in part-load 
tests is 1% of the target liquid flow rate.
    5.1.2. Option 2: Determine IEER by Interpolation and 
Extrapolation.
    Test at the inlet water temperatures described in Tables 2 and 3 
of this appendix, then interpolate and extrapolate to the IEER inlet 
water temperatures specified in Table 4 of this appendix. Sections 
5.1.2.1 through 5.1.2.6 of this appendix specify the steps required 
to determine IEER using Option 2.
    5.1.2.1. Measure Capacity at Option 2 Inlet Water Temperatures.
    For all units, conduct full-load cooling tests at the inlet 
water temperatures as specified in section 5.1.2.1.1 of this 
appendix. For staged capacity controlled and proportionally 
controlled units, conduct part-load cooling tests at the inlet water 
temperatures as specified in section 5.1.2.1.2 of this appendix. 
Perform all tests according to provisions outlined in sections 2 
through 4 and 7 of this appendix. No part-load cooling tests are 
required for fixed-capacity controlled units.
    For all tests, measure the following values: cooling capacity; 
total power; compressor power; condenser section power; control 
circuit power and any auxiliary loads; and indoor fan power. 
Condenser section power must be determined in accordance with 
section 4.4.1 and 4.4.2 of this appendix.
    5.1.2.1.1. Full-load Tests.
    For all units, perform tests to determine full-load capacity at 
each of the conditions specified in Table 2 of this appendix. Follow 
all provisions for full-load cooling airflow in section 3 of this 
appendix.
    The full-load cooling liquid flow rate shall be determined 
during the ``CFL3 high temperature'' test in Table 2 of this 
appendix, using fixed inlet and outlet water temperatures. For the 
``CFL2 medium temperature'' and ``CFL1 low temperature'' tests in 
Table 2 of this appendix, use the liquid flow rate obtained during 
the ``CFL3 high temperature'' test in Table 2 of this appendix with 
a condition tolerance on liquid flow rate of 1% of the target liquid 
flow rate.

                                Table 2--IEER Option 2 Full-Load Test Conditions
----------------------------------------------------------------------------------------------------------------
                                                                     CFL3 high      CFL2 medium      CFL1 low
                            Test name                               temperature     temperature     temperature
----------------------------------------------------------------------------------------------------------------
Air entering indoor side:
    Dry bulb, [deg]F............................................            80.0            80.0            80.0

[[Page 53354]]

 
    Wet bulb, [deg]F............................................            67.0            67.0            67.0
Condenser liquid temperature:
    Entering, [deg]F............................................            86.0            77.0            59.0
    Leaving, [deg]F.............................................            96.0      See note 1      See note 1
----------------------------------------------------------------------------------------------------------------
Notes
1. All full-load tests must be conducted at the liquid flow rate as determined from the CFL3 high temperature
  cooling test.

Where:

CFL3 = The highest temperature Cooling Full-Load test at temperature 
conditions as defined in Table 2
CFL2 = The medium temperature Cooling Full-Load test at temperature 
conditions as defined in Table 2
CFL1 = The lowest temperature Cooling Full-Load test at temperature 
conditions as defined in Table 2

    5.1.2.1.2. Part-load Tests.
    For staged-capacity controlled units and proportionally 
controlled units, additionally perform tests to determine part-load 
capacity at each of the conditions specified in Table 3 of this 
appendix. Perform all part-load tests using the minimum compressor 
speed of the unit. Follow all provisions for part-load cooling 
airflow in section 3 of this appendix.
    Except as adjusted for operation at low condenser temperatures 
per Section E7 of AHRI 340/360-2022, for part-load cooling tests, 
use manufacturer-specified liquid flow rates. For all part-load 
cooling tests, the liquid flow rate shall not exceed the liquid flow 
rate used for the cooling full-load tests. If the manufacturer-
specified part-load cooling liquid flow rate is higher than the 
liquid flow rate used for the cooling full-load tests, use the 
liquid flow rate used for the cooling full-load tests. If no 
manufacturer-specified value for part-load cooling liquid flow rate 
is provided, use the liquid flow rate used for the cooling full-load 
tests. The condition tolerance on liquid flow rate is 1% of the 
target liquid flow rate.

                                Table 3--IEER Option 2 Part-Load Test Conditions
----------------------------------------------------------------------------------------------------------------
                                                                     CPL3 high      CPL2 medium      CPL1 low
                            Test name                               temperature     temperature     temperature
----------------------------------------------------------------------------------------------------------------
Air entering indoor side:
    Dry bulb, [deg]F............................................            80.0            80.0            80.0
    Wet bulb, [deg]F............................................            67.0            67.0            67.0
Condenser liquid temperature:
    Entering, [deg]F............................................            86.0            68.0            59.0
----------------------------------------------------------------------------------------------------------------

Where:

CPL3 = The highest temperature Cooling Part-Load test at temperature 
conditions as defined in Table 3
CPL2 = The medium temperature Cooling Part-Load test at temperature 
conditions as defined in Table 3
CPL1 = The lowest temperature Cooling Part-Load test at temperature 
conditions as defined in Table 3

    5.1.2.2. Interpolate and Extrapolate Measurements to IEER 
Entering Liquid Temperatures.
    Use sections 5.1.2.2.1 and 5.1.2.2.2 of this appendix to 
interpolate and extrapolate the values measured in section 5.1.2.1 
of this appendix from the inlet water temperatures used in Tables 2 
and 3 of this appendix to the IEER inlet water temperatures 
specified in Table 4 of this appendix.

                                            Table 4--IEER Conditions
----------------------------------------------------------------------------------------------------------------
                                                                                     Entering
                                                                                      liquid         Weighting
              IEER point                     Capacity level        Percent load     temperature     factor [%]
                                                                                     [[deg]F]
----------------------------------------------------------------------------------------------------------------
A.....................................  Full....................             100            85.0             2.0
B.....................................  Part....................              75            73.5            61.7
C.....................................  Part....................              50            62.0            23.8
D.....................................  Part....................              25            55.0            12.5
----------------------------------------------------------------------------------------------------------------

    5.1.2.2.1. Full Load.
    For all units, calculate the full-load capacity and total power 
at IEER points A through D using Equation 2 of this appendix and the 
parameters outlined in Table 5 of this appendix.
    For fixed-capacity control units, also calculate the full-load 
compressor power, condenser section power, control circuit power and 
any auxiliary loads, and indoor fan power at IEER points B through D 
using Equation 2 of this appendix and the parameters outlined in 
Table 5 of this appendix.
    The interpolated value of each parameter is designated by 
Vcalc in Equation 2 of this appendix.
[GRAPHIC] [TIFF OMITTED] TP30AU22.039


[[Page 53355]]



                                  Table 5--Full-Load Interpolation Input Values
----------------------------------------------------------------------------------------------------------------
                                Tlow [[deg]F]  Thigh [[deg]F]  Tcalc [[deg]F]
          IEER point                                                                Vlow\1\          Vhigh\1\
----------------------------------------------------------------------------------------------------------------
A............................            77.0            86.0            85.0  Value from CFL2   Value from CFL3
                                                                                Medium            High
                                                                                Temperature.      Temperature.
B............................            59.0            77.0            73.5  Value from CFL1.  Value from CFL2
                                                                               Low Temperature.  Medium
                                                                                                  Temperature.
C............................            59.0            77.0            62.0  Value from CFL1.  Value from CFL2
                                                                               Low Temperature.  Medium
                                                                                                  Temperature.
D............................            59.0            77.0            55.0  Value from CFL1.  Value from CFL2
                                                                               Low Temperature.  Medium
                                                                                                  Temperature.
----------------------------------------------------------------------------------------------------------------
Notes
1. For each given measured value (i.e., cooling capacity; total power; compressor power; condenser section
  power; control circuit power and any auxiliary loads; and indoor fan power), use the measured value from the
  specified test in Table 2 of this appendix.

    5.1.2.2.2. Part Load.
    For staged-capacity controlled and proportionally controlled 
units, calculate the part-load capacity, total power, compressor 
power, condenser section power, control circuit power and any 
auxiliary loads, and indoor fan power at IEER points B through D 
using Equation 2 of this appendix and the parameters outlined in 
Table 6 of this appendix. The interpolated value of each parameter 
is designated by Vcalc in Equation 2 of this appendix.

                                  Table 6--Part-Load Interpolation Input Values
----------------------------------------------------------------------------------------------------------------
                               Tlow  [[deg]F]       Thigh           Tcalc
          IEER point                              [[deg]F]        [[deg]F]         Vlow \1\         Vhigh \1\
----------------------------------------------------------------------------------------------------------------
B............................            68.0            86.0            73.5  Value from CPL2   Value from CPL3
                                                                                Medium            High
                                                                                Temperature.      Temperature.
C............................            59.0            68.0            62.0  Value from CPL1   Value from CPL2
                                                                                Low Temperature.  Medium
                                                                                                  Temperature
D............................            59.0            68.0            55.0  Value from CPL1   Value from CPL2
                                                                                Low Temperature.  Medium
                                                                                                  Temperature
----------------------------------------------------------------------------------------------------------------
Notes:
\1\ For each given measured value (i.e., cooling capacity; total power; compressor power; condenser section
  power; control circuit power and any auxiliary loads; and indoor fan power), use the measured value from the
  specified test in Table 3 of this appendix.

    5.1.2.3. Calculate Full-load and Part-load EERs at IEER Points.
    For all units, calculate the full-load EER for each IEER point A 
through D of Table 5 as the ratio of the full-load capacity in Btu/h 
to the full-load total power in W determined in section 5.1.2.2.1 of 
this appendix.
    For staged capacity controlled and proportionally controlled 
units, also calculate the part-load EER for each IEER point B 
through D of Table 5 as the ratio of the part-load capacity in Btu/h 
to the part-load total power in W determined in section 5.1.2.2.2 of 
this appendix.
    5.1.2.4. Determine Tested Percent Load at IEER Points B Through 
D.
    For all units, use Equation 3 to divide the interpolated full-
load capacity values at IEER points B through D (determined in 
section 5.1.2.2.1 of this appendix) by the full-load capacity at 
IEER point A (determined in section 5.1.2.2.1 of this appendix).
    For staged capacity control units and proportionally controlled 
units, use Equation 3 to divide the interpolated part-load capacity 
values at IEER points B through D (determined in section 5.1.2.2.2 
of this appendix), by the full-load capacity at IEER point A 
(determined in section 5.1.2.2.1 of this appendix).
    The values calculated at this stage are referred to as ``tested 
percent load'' in section 5.1.2.5 of this appendix.
[GRAPHIC] [TIFF OMITTED] TP30AU22.040

Where:

PLTested = The full-load or part-load tested percent load 
at a given IEER point
qx = The full-load or part-load capacity at a given IEER 
point calculated in sections 5.1.2.2.1 and 5.1.2.2.2 of this 
appendix for IEER points B through D, Btu/h
qA, FL = The full-load capacity calculated in section 
5.1.2.2.1 of this appendix for IEER point A, Btu/h

    5.1.2.5. Determine EER at the IEER Load Level for IEER Points B 
Through D.
    For each of the IEER points B through D of Table 5, determine 
the EER at the IEER percent load specified in Table 4 of this 
appendix (i.e., 75, 50, or 25). For each IEER point B through D of 
Table 5, if the full-load or part-load tested percent load 
calculated in section 5.1.2.4 of this appendix is within the allowed 
range specified in Table 7 of this appendix, use the corresponding 
EER determined in section 5.1.2.3 of this appendix as the EER for 
the IEER point. In all other cases, the EER must be determined by 
adjustments as described in sections 0 and 5.1.2.5.2 of this 
appendix.

                                    Table 7--Tolerance on Capacity Percentage
----------------------------------------------------------------------------------------------------------------
                                                                                      Minimum         Maximum
                                                                  Target percent     allowable       allowable
                           IEER point                                  load       tested percent  tested percent
                                                                                       load            load
----------------------------------------------------------------------------------------------------------------
B...............................................................              75              72              78
C...............................................................              50              47              53
D...............................................................              25              22              28
----------------------------------------------------------------------------------------------------------------


[[Page 53356]]

    5.1.2.5.1. Fixed-capacity Control Units.
    For fixed-capacity control units, perform all adjustments of EER 
values by cyclic degradation of the full-load EERs to account for 
the impact of the compressor cycling to meet a load. Perform the 
adjustments as specified in section 5.1.2.5.4 of this appendix.
    5.1.2.5.2. Staged Capacity Control Units and Proportionally 
Controlled Units.
    For IEER points B through D of Table 5, if the part-load tested 
percent load calculated in section 5.1.2.4 of this appendix is below 
the minimum allowable tested percent load in Table 7 of this 
appendix, calculate EER for this IEER point by interpolating between 
the full-load EER and part-load EER as specified in section 
5.1.2.5.3 of this appendix. If the part-load tested percent load 
calculated in section 5.1.2.4 of this appendix is above the maximum 
allowable tested percent load in Table 7 of this appendix, calculate 
EER for this point using the cyclic degradation adjustment in 
section 5.1.2.5.4 of this appendix.
    5.1.2.5.3. Calculate EER by Interpolation Between Full Load and 
Part Load.
    Calculate EER at a single IEER point by interpolating between 
the full-load tested percent load and the part-load tested percent 
load calculated in section 5.1.2.4 of this appendix to the IEER 
point load percentage specified in Table 4 of this appendix, as 
shown in Equation 4 of this appendix.
[GRAPHIC] [TIFF OMITTED] TP30AU22.041

Where:

PLTarget = The IEER load fraction at the desired rating 
condition from Table 4 of this appendix, represented as a percentage 
(i.e., 75, 50, or 25)
PLTested,PL = The part-load tested percent load at the 
desired rating condition calculated in section 5.1.2.4 of this 
appendix
PLTested,FL = The full-load tested percent load at the 
desired rating condition calculated in section 5.1.2.4 of this 
appendix
EERPL = The part-load EER calculated in section 5.1.2.3 
of this appendix
EERFL = The full-load EER calculated in section 5.1.2.3 
of this appendix

    5.1.2.5.4. Calculate EER by Cyclic Degradation.
    For fixed capacity control units, adjust the full-load EER at a 
single IEER point for cyclic degradation by using Equation 5 through 
Equation 7 of this appendix with values calculated for full load in 
section 5.1.2.2.1 of this appendix.
    For staged capacity control and proportionally controlled units, 
adjust the part-load EER at a single IEER point for cyclic 
degradation by using Equation 5 through Equation 7 of this appendix 
with values calculated for part load in section 5.1.2.2.2 of this 
appendix.
[GRAPHIC] [TIFF OMITTED] TP30AU22.042

[GRAPHIC] [TIFF OMITTED] TP30AU22.043

[GRAPHIC] [TIFF OMITTED] TP30AU22.044

Where:

PLTested = The tested percent load calculated in section 
5.1.2.4 of this appendix
PLTarget = The IEER percentage of full load from Table 4 
of this appendix, represented as a percentage (i.e., 75, 50, or 25)
PC = Compressor power at a given IEER point calculated in 
section 5.1.2.2 of this appendix for IEER points B through D, W
PCD = Condenser Section power, including the total 
pumping effect calculated in section 4.3 of this appendix, at a 
given IEER point calculated in section 5.1.2.2 of this appendix for 
IEER points B through D, W
PCT = Control circuit power and any auxiliary loads at a 
given IEER point calculated in section 5.1.2.2 of this appendix for 
IEER points B through D, W
PIF = Indoor fan power at a given IEER point calculated 
in section 5.1.2.2 of this appendix for IEER points B through D, W
qx = The full-load or part-load capacity at a given IEER 
point calculated in section 5.1.2.2 of this appendix for IEER points 
B through D, Btu/h

    5.1.2.6. Calculate IEER.
    Use Equation 8 of this appendix to calculate IEER as a weighted 
mean of the EERs determined at each of the IEER points.

[[Page 53357]]

[GRAPHIC] [TIFF OMITTED] TP30AU22.045

Where:

EERA = Full-load EER at IEER point A determined in 
section 5.1.2.3 of this appendix.
EERB = EER at IEER point B determined in section 5.1.2.5 
of this appendix
EERC = EER at IEER point C determined in section 5.1.2.5 
of this appendix
EERD = >EER at IEER point D determined in section 5.1.2.5 
of this appendix

    5.2. Optional Representations of EER.
    Representations of EER at any full-load or part-load conditions, 
made using conditions specified in section 5.1.2.1.1 or 5.1.2.1.2 of 
this appendix and the provisions of sections 2 through 4 and 7 of 
this appendix are optional.
    6. Heating Rating.
    6.1. Liquid Flow Rate.
    If IEER was determined using Option 1 in section 5.1 of this 
appendix, use the liquid flow rate determined from the ``Standard 
Rating Conditions Cooling'' test for water-cooled equipment as 
defined in Table 6 of AHRI 340/360-2022 for all heating tests. If 
IEER was determined using Option 2 in section 5.1 of this appendix, 
use the liquid flow rate determined from the CFL3 high temperature 
cooling test in section 5.1.2.1.1 of this appendix for all heating 
tests in Tables 8 and 9 of this appendix. The condition tolerance on 
liquid flow rate is 1%.
    6.2. Methods for Determining COP.
    Determine the COP using one of two options, as described in the 
following sections 6.2.1 and 6.2.2 of this appendix.
    6.2.1. Option A: Determine COP by Testing at Conditions 
Specified in Table 8 of this Appendix.
    Determine COP according to the applicable provisions in sections 
2 through 4 and 7 of this appendix using the conditions in Table 8 
of this appendix. Use the liquid flow rate specified in section 6.1 
of this appendix.

               Table 8--Standard Heating Rating Conditions
------------------------------------------------------------------------
                                                           HFL0  rating
                        Test name                           temperature
------------------------------------------------------------------------
Air entering indoor side
    Dry bulb, [deg]F....................................            70.0
    Wet bulb, [deg]F....................................      60.0 (max)
Liquid temperature
    Entering, [deg]F....................................            55.0
    Leaving, [deg]F.....................................      See note 1
------------------------------------------------------------------------
Notes
1. All heating tests must be conducted at the liquid flow rate specified
  in section 6.1 of this appendix.

Where:

HFL0 = The standard rating condition Heating Full-Load test as 
defined in Table 8
    6.2.2. Option B: Determine COP by Interpolation.
    Test at the HFL3 and HFL2 conditions in Table 9 of this 
appendix, then interpolate to the HFL0 inlet water temperature 
specified in Table 8 of this appendix. Sections 6.2.2.1 and 6.2.2.2 
of this appendix specify the steps required to determine COP using 
Option B.

                                   Table 9--Optional Heating Rating Conditions
----------------------------------------------------------------------------------------------------------------
                                                                    HFL3  high     HFL2  Medium      HFL1  Low
                            Test name                               temperature     temperature     temperature
----------------------------------------------------------------------------------------------------------------
Air entering indoor side
    Dry bulb, [deg]F............................................            70.0            70.0            70.0
    Wet bulb, [deg]F............................................      60.0 (max)      60.0 (max)      60.0 (max)
Liquid temperature
    Entering, [deg]F............................................            68.0            50.0            32.0
    Leaving, [deg]F.............................................      See note 1      See note 1      See note 1
----------------------------------------------------------------------------------------------------------------
Notes
1. All heating tests must be conducted at the liquid flow rate specified in section 6.1 of this appendix.

Where:

HFL3 = The highest temperature Heating Full-Load test at temperature 
conditions as defined in Table 9
HFL2 = The medium temperature Heating Full-Load test at temperature 
conditions as defined in Table 9
HFL1 = The lowest temperature Heating Full-Load test at temperature 
conditions as defined in Table 9
    6.2.2.2. Measure Capacity and Total Power at Option B Inlet 
Water Temperatures.
    Conduct heating tests at the HFL3 and HFL2 conditions specified 
in Table 9 of this appendix according to the applicable provisions 
in sections 2 through 4 and 7 of this appendix. The liquid flow rate 
must be set as defined in section 6.1 of this appendix. For all 
tests, measure heating capacity and total power.
    6.2.2.3. Interpolate Measurements to COP Entering Liquid 
Temperature.
    Interpolate the heating capacity and total power values measured 
in section 6.2.2.1 of this appendix from the inlet liquid 
temperatures used in section 6.2.2.1 of this appendix to the inlet 
liquid temperature specified in Table 8 of this appendix. Use 
Equation 9 of this appendix and the parameters outlined in Table 10 
of this appendix. The interpolated value of each parameter is 
designated by Vcalc in Equation 9 of this appendix.
[GRAPHIC] [TIFF OMITTED] TP30AU22.046


[[Page 53358]]



                                  Table 10--Heating Interpolation Input Values
----------------------------------------------------------------------------------------------------------------
                                     Thigh [[deg]F]   Tcalc [[deg]F]
           Tlow [[deg]F]                                                    Vlow \1\              Vhigh \1\
----------------------------------------------------------------------------------------------------------------
50.0..............................            68.0             55.0   Value from HFL2       Value from HFL3 High
                                                                       Medium Temperature.   Temperature
----------------------------------------------------------------------------------------------------------------
Notes
1. For each given measured value (i.e., heating capacity in W and total power in W), use the measured value from
  the specified test in Table 9 of this appendix.

    6.2.2.4. Calculate COP as the ratio of the interpolated heating 
capacity in W to the interpolated total power in W calculated in 
section 6.2.2.2 of this appendix.
    6.3. Optional Representations of COP.
    Representations of COP using the conditions specified in Table 9 
of this appendix are optional and are determined according to the 
applicable provisions of sections 2 through 4 and 7 of this 
appendix. The liquid flow rate must be set as defined in section 6.1 
of this appendix.
    Representations of part-load COP using the conditions specified 
in Table 11 of this appendix are optional and are determined 
according to the applicable provisions of sections 2 through 4 and 7 
of this appendix. For part-load heating tests, use manufacturer-
specified liquid flow rates. For all part-load heating tests, the 
liquid flow rate shall not exceed the liquid flow rate defined in 
section 6.1 of this appendix. If the manufacturer-specified part-
load heating liquid flow rate is higher than the liquid flow rate 
used for the cooling full-load tests, use the liquid flow rate used 
for the cooling full-load tests. If no manufacturer-specified value 
for part-load heating liquid flow rate is provided, use the liquid 
flow rate defined in section 6.1 of this appendix. The condition 
tolerance on liquid flow rate is 1%.

                                 Table 11--Optional Part-Load Heating Conditions
----------------------------------------------------------------------------------------------------------------
                                                                     HPL3 high      HPL2 medium      HPL1 low
                            Test name                               temperature     temperature     temperature
----------------------------------------------------------------------------------------------------------------
Air entering indoor side:
    Dry bulb, [deg]F............................................            70.0            70.0            70.0
    Wet bulb, [deg]F............................................      60.0 (max)      60.0 (max)      60.0 (max)
Liquid temperature:
    Entering, [deg]F............................................            68.0            50.0            41.0
----------------------------------------------------------------------------------------------------------------

Where:

HPL3 = The highest temperature Heating Part-Load test at temperature 
conditions as defined in Table 11
HPL2 = The medium temperature Heating Part-Load test at temperature 
conditions as defined in Table 11
HPL1 = The lowest temperature Heating Part-Load test at temperature 
conditions as defined in Table 11

    7. Set-Up and Test Provisions for Specific Components.
    When testing a WSHP that includes any of the features listed in 
Table 12 of this appendix, test in accordance with the set-up and 
test provisions specified in Table 12 of this appendix.

            Table 12--Test Provisions for Specific Components
------------------------------------------------------------------------
          Component                Description         Test provisions
------------------------------------------------------------------------
Desiccant Dehumidification    An assembly that      Disable desiccant
 Components.                   reduces the           dehumidification
                               moisture content of   components for
                               the supply air        testing.
                               through moisture
                               transfer with solid
                               or liquid
                               desiccants.
Air Economizers.............  An automatic system   For any air
                               that enables a        economizer that is
                               cooling system to     factory-installed,
                               supply outdoor air    place the
                               to reduce or          economizer in the
                               eliminate the need    100% return
                               for mechanical        position and close
                               cooling during mild   and seal the
                               or cold weather.      outside air dampers
                                                     for testing. For
                                                     any modular air
                                                     economizer shipped
                                                     with the unit but
                                                     not factory-
                                                     installed, do not
                                                     install the
                                                     economizer for
                                                     testing.
Fresh Air Dampers...........  An assembly with      For any fresh air
                               dampers and means     dampers that are
                               to set the damper     factory-installed,
                               position in a         close and seal the
                               closed and one open   dampers for
                               position to allow     testing. For any
                               air to be drawn       modular fresh air
                               into the equipment    dampers shipped
                               when the indoor fan   with the unit but
                               is operating.         not factory-
                                                     installed, do not
                                                     install the dampers
                                                     for testing.
Power Correction Capacitors.  A capacitor that      Remove power
                               increases the power   correction
                               factor measured at    capacitors for
                               the line connection   testing.
                               to the equipment.
Ventilation Energy Recovery   An assembly that      For any VERS that is
 System (VERS).                preconditions         factory-installed,
                               outdoor air           place the VERS in
                               entering the          the 100% return
                               equipment through     position and close
                               direct or indirect    and seal the
                               thermal and/or        outside air dampers
                               moisture exchange     and exhaust air
                               with the exhaust      dampers for
                               air, which is         testing, and do not
                               defined as the        energize any VERS
                               building air being    subcomponents
                               exhausted to the      (e.g., energy
                               outside from the      recovery wheel
                               equipment.            motors). For any
                                                     VERS module shipped
                                                     with the unit but
                                                     not factory-
                                                     installed, do not
                                                     install the VERS
                                                     for testing.

[[Page 53359]]

 
Barometric Relief Dampers...  An assembly with      For any barometric
                               dampers and means     relief dampers that
                               to automatically      are factory-
                               set the damper        installed, close
                               position in a         and seal the
                               closed position and   dampers for
                               one or more open      testing. For any
                               positions to allow    modular barometric
                               venting directly to   relief dampers
                               the outside a         shipped with the
                               portion of the        unit but not
                               building air that     factory-installed,
                               is returning to the   do not install the
                               unit, rather than     dampers for
                               allowing it to        testing.
                               recirculate to the
                               indoor coil and
                               back to the
                               building.
UV Lights...................  A lighting fixture    Turn off UV lights
                               and lamp mounted so   for testing.
                               that it shines
                               light on the indoor
                               coil, that emits
                               ultraviolet light
                               to inhibit growth
                               of organisms on the
                               indoor coil
                               surfaces, the
                               condensate drip
                               pan, and/other
                               locations within
                               the equipment.
Steam/Hydronic Heat Coils...  Coils used to         Test with steam/
                               provide               hydronic heat coils
                               supplemental          in place but
                               heating.              providing no heat.
Refrigerant Reheat..........  A heat exchanger      De-activate
                               located downstream    refrigerant reheat
                               of the indoor coil    coils for testing
                               that heats the        so as to provide
                               supply air during     the minimum (none
                               cooling operation     if possible) reheat
                               using high-pressure   achievable by the
                               refrigerant in        system controls.
                               order to increase
                               the ratio of
                               moisture removal to
                               cooling capacity
                               provided by the
                               equipment.
Fire/Smoke/Isolation Dampers  A damper assembly     For any fire/smoke/
                               including means to    isolation dampers
                               open and close the    that are factory-
                               damper mounted at     installed, set the
                               the supply or         dampers in the
                               return duct opening   fully open position
                               of the equipment.     for testing. For
                                                     any modular fire/
                                                     smoke/isolation
                                                     dampers shipped
                                                     with the unit but
                                                     not factory-
                                                     installed, do not
                                                     install the dampers
                                                     for testing.
Process Heat recovery/        A heat exchanger      Disconnect the heat
 Reclaim Coils/Thermal         located inside the    exchanger from its
 Storage.                      unit that             heat source for
                               conditions the        testing.
                               equipment's supply
                               air using energy
                               transferred from an
                               external source
                               using a vapor, gas,
                               or liquid.
------------------------------------------------------------------------

[FR Doc. 2022-17075 Filed 8-29-22; 8:45 am]
BILLING CODE 6450-01-P