[Federal Register Volume 87, Number 57 (Thursday, March 24, 2022)]
[Proposed Rules]
[Pages 16830-16884]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-04269]



[[Page 16829]]

Vol. 87

Thursday,

No. 57

March 24, 2022

Part II





Department of Energy





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10 CFR Parts 429 and 430





Energy Conservation Program: Test Procedure for Test Procedures for 
Central Air Conditioners and Heat Pumps; Proposed Rule

  Federal Register / Vol. 87 , No. 57 / Thursday, March 24, 2022 / 
Proposed Rules  

[[Page 16830]]


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DEPARTMENT OF ENERGY

10 CFR Parts 429 and 430

[EERE-2021-BT-TP-0030]
RIN 1904-AF29


Energy Conservation Program: Test Procedure for Test Procedures 
for Central Air Conditioners and 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 the 
test procedures for central air conditioners and heat pumps that will 
be required for certification of compliance with applicable energy 
conservation standards starting January 1, 2023 to address a limited 
number of specific issues. DOE is seeking comment from interested 
parties on the proposal.

DATES: DOE will accept comments, data, and information regarding this 
proposal no later than May 23, 2022. See section V, ``Public 
Participation,'' for details. DOE will hold a webinar on Monday, April 
18, 2022, from 1 p.m. to 4 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. Follow the 
instructions for submitting comments. Alternatively, interested persons 
may submit comments, identified by docket number EERE-2021-BT-TP-0030 
by any of the following methods:
    1. Federal eRulemaking Portal: www.regulations.gov. Follow the 
instructions for submitting comments.
    2. Email: to [email protected]. Include 
docket number EERE-2021-BT-TP-0030 in the subject line of the message.
    No telefacsimiles (``faxes'') will be accepted. For detailed 
instructions on submitting comments and additional information on this 
process, see section V of this document.
    Although DOE has routinely accepted public comment submissions 
through a variety of mechanisms, including postal mail and hand 
delivery/courier, the Department has found it necessary to make 
temporary modifications to the comment submission process in light of 
the ongoing COVID-19 pandemic. DOE is currently suspending receipt of 
public comments via postal mail and hand delivery/courier. If a 
commenter finds that this change poses an undue hardship, please 
contact Appliance Standards Program staff at (202) 586-1445 to discuss 
the need for alternative arrangements. Once the COVID-19 pandemic 
health emergency is resolved, DOE anticipates resuming all of its 
regular options for public comment submission, including postal mail 
and hand delivery/courier.
    Docket: The docket, which includes Federal Register notices, public 
meeting attendee lists and transcripts, comments, and other supporting 
documents/materials, is available for review at www.regulations.gov. 
All documents in the docket are listed in the www.regulations.gov 
index. However, some documents listed in the index, such as those 
containing information that is exempt from public disclosure, may not 
be publicly available.
    The docket web page can be found at www.regulations.gov/docket/EERE-2021-BT-TP-0030. The docket web page contains instructions on how 
to access all documents, including public comments, in the docket. See 
section V for information on how to submit comments through 
www.regulations.gov.

FOR FURTHER INFORMATION CONTACT: 
    Ms. Catherine Rivest, U.S. Department of Energy, Office of Energy 
Efficiency and Renewable Energy, Building Technologies Office, EE-2J, 
1000 Independence Avenue SW, Washington, DC 20585-0121. Telephone: 
(202) 586-7335. Email [email protected].
    Mr. Pete Cochran, U.S. Department of Energy, Office of the General 
Counsel, GC-33, 1000 Independence Avenue SW, Washington, DC 20585-0121. 
Telephone: (202) 586-9496. Email: [email protected].
    For further information on how to submit a comment, review other 
public comments and the docket, or participate in a public meeting, 
contact the Appliance and Equipment Standards Program staff at (202) 
287-1445 or by email: [email protected].

SUPPLEMENTARY INFORMATION: DOE proposes to maintain the following 
previously approved incorporations by references in 10 CFR part 430:
    ANSI/AHRI 210/240-2008 with Addenda 1 and 2, 2008 Standard for 
Performance Rating of Unitary Air-Conditioning & Air-Source Heat Pump 
Equipment, ANSI approved October 27, 2011;
    ANSI/AHRI 1230-2010 with Addendum 2, 2010 Standard for Performance 
Rating of Variable Refrigerant Flow (VRF) Multi-Split Air-Conditioning 
and Heat Pump Equipment, ANSI approved August 2, 2010.
    Copies of AHRI 210/240-2008 and AHRI 1230-2010 can be obtained from 
the Air-Conditioning, Heating, and Refrigeration Institute, 2111 Wilson 
Boulevard, Suite 500, Arlington, VA 22201, (703) 524-8800, or by going 
to www.ahrinet.org.
    ANSI/ASHRAE 23.1-2010, Methods of Testing for Rating the 
Performance of Positive Displacement Refrigerant Compressors and 
Condensing Units that Operate at Subcritical Temperatures of the 
Refrigerant, ANSI approved January 28, 2010;
    ANSI/ASHRAE Standard 37-2009, Methods of Testing for Rating 
Electrically Driven Unitary Air-Conditioning and Heat Pump Equipment, 
ANSI approved June 25, 2009;
    ANSI/ASHRAE 41.1-2013, Standard Method for Temperature Measurement, 
ANSI approved January 30, 2013;
    ANSI/ASHRAE 41.2-1987 (Reaffirmed 1992), ``Standard Methods for 
Laboratory Airflow Measurement,'' ANSI approved April 20, 1992;
    ANSI/ASHRAE 41.6-2014, Standard Method for Humidity Measurement, 
ANSI approved July 3, 2014;
    ANSI/ASHRAE 41.9-2011, Standard Methods for Volatile-Refrigerant 
Mass Flow Measurements Using Calorimeters, ANSI approved February 3, 
2011;
    ANSI/ASHRAE 116-2010, Methods of Testing for Rating Seasonal 
Efficiency of Unitary Air Conditioners and Heat Pumps, ANSI approved 
February 24, 2010.
    Copies of ASHRAE 23.1-2010, ANSI/ASHRAE 37-2009, ANSI/ASHRAE 41.1-
2013, ASHRAE 41.2-1987 (RA 1992), ASHRAE 41.6-2014, ASHRAE 41.9-2011, 
and ASHRAE 116-2010 can be purchased from www.ashrae.org/resources_
publications.
    ANSI/AMCA 210-2007, ANSI/ASHRAE 51-2007, Laboratory Methods of 
Testing Fans for Certified Aerodynamic Performance Rating, Figure 2A 
and Figure 12, ANSI approved August 17, 2007.
    Copies of AMCA 210-2007 can be purchased from www.amca.org/store/index.php.
    For a further discussion of these standards, see section IV.M of 
this document.

[[Page 16831]]

Table of Contents

I. Authority and Background
    A. Authority
    B. Background
    C. Deviation From Appendix A
II. Synopsis of the Notice of Proposed Rulemaking
III. Discussion
    A. Scope of Applicability
    B. Topics Arising From Test Procedure Waivers
    1. Fan Power at Reduced Airflows for Coil-Only Systems
    2. Variable-Speed Coil-Only Test Procedure
    3. Space-Constrained Coil-Only CAC Ratings
    C. Other Test Procedure Revisions
    1. Air Volume Rate Changing With Outdoor Conditions
    2. Wet Bulb Temperature for H4 5 [deg]F Heating Tests
    3. Hierarchy of Manufacturer Installation Instructions
    4. Adjusting Airflow Measurement Apparatus To Achieve Desired 
SCFM at Part-Load Conditions
    5. Revision of Equations Representing Full-Speed Variable-Speed 
Heat Pump Operation at and Above 45 [deg]F Ambient Temperature
    6. Calculations for Triple-Capacity Northern Heat Pumps
    7. Heating Nominal Air Volume Rate for Variable-Speed Heat Pumps
    8. Clarifications for HSPF2 Calculation
    9. Distinguishing Central Air Conditioners and Heat Pumps From 
Commercial Equipment
    10. Additional Test Procedure Revisions
    D. Other Representation Proposed Revisions
    1. Required Represented Values for Models Certified Compliant 
With Regional Standards
    E. Test Procedure Costs and Impact
    F. Compliance Date and Waivers
IV. Procedural Issues and Regulatory Review
    A. Review Under Executive Order 12866
    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. Submission of Comments
    B. Issues on Which DOE Seeks Comment
    C. Participation in the Webinar
    D. Conduct of the Webinar
VI. Approval of the Office of the Secretary

I. Authority and Background

    Central air conditioners (``CACs'') and central air conditioning 
heat pumps (``HPs'') (collectively, ``CAC/HPs'') are included in the 
list of ``covered products'' for which DOE is authorized to establish 
and amend energy conservation standards and test procedures (42 U.S.C. 
6292(a)(3)). DOE's energy conservation standards and test procedures 
for CAC/HPs are currently prescribed at title 10 of the Code of Federal 
Regulations (``CFR''), part 430 section 32(c), and 10 CFR part 430 
subpart B appendices M (``Appendix M'') and M1 (``Appendix M1''). The 
following sections discuss DOE's authority to establish test procedures 
for CAC/HPs and relevant background information regarding DOE's 
consideration of test procedures for this product.

A. Authority

    The Energy Policy and Conservation Act, as amended (``EPCA''),\1\ 
authorizes DOE to regulate the energy efficiency of a number of 
consumer products and certain industrial equipment. (42 U.S.C. 6291-
6317) Title III, Part B \2\ of EPCA established the Energy Conservation 
Program for Consumer Products Other Than Automobiles, which sets forth 
a variety of provisions designed to improve energy efficiency. These 
products include CAC/HPs,\3\ the subject of this document. (42 U.S.C. 
6292(a)(3))
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    \1\ All references to EPCA in this document refer to the statute 
as amended through the Energy Act of 2020, Public Law 116-260 (Dec. 
27, 2020).
    \2\ For editorial reasons, upon codification in the U.S. Code, 
Part B was redesignated Part A.
    \3\ This rulemaking uses the term ``CAC/HP'' to refer 
specifically to central air conditioners (which include heat pumps) 
as defined by EPCA. (42 U.S.C. 6291(21))
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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. 6291), 
test procedures (42 U.S.C. 6293), labeling provisions (42 U.S.C. 6294), 
energy conservation standards (42 U.S.C. 6295), and the authority to 
require information and reports from manufacturers (42 U.S.C. 6296).
    The Federal testing requirements consist of test procedures that 
manufacturers of covered products must use as the basis for: (1) 
Certifying to DOE that their products comply with the applicable energy 
conservation standards adopted pursuant to EPCA (42 U.S.C. 6295(s)), 
and (2) making representations about the efficiency of those consumer 
products (42 U.S.C. 6293(c)). Similarly, DOE must use these test 
procedures to determine whether the products comply with relevant 
standards promulgated under EPCA. (42 U.S.C. 6295(s))
    Federal energy efficiency requirements for covered products 
established under EPCA generally supersede State laws and regulations 
concerning energy conservation testing, labeling, and standards. (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. 6297(d))
    Under 42 U.S.C. 6293, EPCA sets forth the criteria and procedures 
DOE must follow when prescribing or amending test procedures for 
covered products. EPCA requires that any test procedures prescribed or 
amended under this section be reasonably designed to produce test 
results which measure energy efficiency, energy use or estimated annual 
operating cost of a covered product during a representative average use 
cycle or period of use and not be unduly burdensome to conduct. (42 
U.S.C. 6293(b)(3))
    If the Secretary determines, on her own behalf or in response to a 
petition by any interested person, that a test procedure should be 
prescribed or amended, the Secretary shall promptly publish in the 
Federal Register proposed test procedures and afford interested persons 
an opportunity to present oral and written data, views, and arguments 
with respect to such procedures. (42 U.S.C. 6293(b)(2)) The comment 
period on a proposed rule to amend a test procedure shall be at least 
60 days and may not exceed 270 days. Id. In prescribing or amending a 
test procedure, the Secretary shall take into account such information 
as the Secretary determines relevant to such procedure, including 
technological developments relating to energy use or energy efficiency 
of the type (or class) of covered products involved. (Id.)
    DOE's regulations at 10 CFR 430.27 provide that any interested 
person may seek a waiver from the test procedure requirements if 
certain conditions are met. A waiver allows manufacturers to use an 
alternate test procedure in situations in which the DOE test procedure 
cannot be used to test the product or equipment, or use of the DOE test 
procedure would generate unrepresentative results. 10 CFR 430.27(a)(1). 
DOE's regulations at 10 CFR 430.27(l) require that as soon as 
practicable after the granting of any waiver, DOE will publish in the 
Federal Register a NOPR to amend its

[[Page 16832]]

regulations so as to eliminate any need for the continuation of such 
waiver. As soon thereafter as practicable, DOE will publish in the 
Federal Register a final rule. 10 CFR 430.27(l). DOE is publishing this 
NOPR for the limited purpose of addressing its obligations under the 
waiver process regulations at 10 CFR 430.27.

B. Background

    As discussed, DOE's existing test procedures for CAC/HPs appear at 
appendix M and appendix M1 (both titled ``Uniform Test Method for 
Measuring the Energy Consumption of Central Air Conditioners and Heat 
Pumps'').
    On January 5, 2017, DOE published a final rule regarding the 
Federal test procedure for CAC/HPs. 82 FR 1426 (``January 2017 Final 
Rule''). The January 2017 Final Rule amended appendix M and established 
appendix M1, use of which is required beginning January 1, 2023 for any 
representations, including compliance certifications, made with respect 
to the energy use or efficiency of CAC/HPs. appendix M provides for the 
measurement of the cooling and heating performance of CAC/HPs using the 
seasonal energy efficiency ratio (``SEER'') metric and heating seasonal 
performance factor (``HSPF'') metric, respectively. appendix M1 
specifies a revised SEER metric (i.e., SEER2) and a revised HSPF metric 
(``HSPF2'').
    Since the publication of the January 2017 Final Rule, DOE has 
granted various petitions for waiver and interim waiver from certain 
provisions of appendix M and/or M1.\4\ Additionally, DOE has become 
aware of certain provisions in appendix M1 for which additional detail 
and direction may be needed to avoid potential confusion and reduce 
test burden. Therefore, DOE is proposing changes to improve the 
functionality of appendix M1 to address these issues.
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    \4\ Waivers granted to GD Midea Heating and Ventilating 
Equipment Co., Ltd. (83 FR 56065), Johnson Controls, Inc. (83 FR 
12735 and 84 FR 52489), and TCL Air Conditioner (Zhongshan) Co., 
Ltd. (84 FR 11941);, interim waivers granted to National Comfort 
Products, Inc. (83 FR 24754), Aerosys Inc. (83 FR 24762), LG 
Electronics U.S.A., Inc. (85 FR 40272), and Goodman Manufacturing 
Company, L.P. (86 FR 40534).
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    In addition, on May 8, 2019, AHRI submitted a comment responding to 
the notice of proposal to revise and adopt procedures, interpretations, 
and policies for consideration of new or revised energy conservation 
standards (2020 Process Rule NOPR, 84 FR 3910, Feb. 13, 2019). The 
comment included as Exhibit 2 a ``List of Errors Found in both appendix 
M and appendix M1'' (``AHRI Exhibit 2'', EERE-2017-BT-STD-0062-0117 at 
pp. 23-24). Many of the errors pointed out by AHRI regard typographical 
errors in appendix M and appendix M1. DOE is addressing these issues in 
this rulemaking.

C. Deviation From Appendix A

    In accordance with section 3(a) of 10 CFR part 430, subpart C, 
appendix A (``Appendix A''), DOE notes that it is deviating from the 
provision in appendix A regarding the early assessment process prior to 
the NOPR stage to notify stakeholders that DOE is considering a 
rulemaking to amend a test procedure and solicit comment on whether an 
amended test procedure would more accurately measure energy efficiency, 
energy use, water use (as specified in EPCA), or estimated annual 
operating cost of a covered product during a representative average use 
cycle or period of use without being unduly burdensome to conduct or 
reduce testing burden. DOE is opting to deviate from this provision by 
proposing changes to the test procedure in this proposed rule without 
first having gone through the early assessment process because DOE has 
already been made aware by stakeholders that the test procedure for 
CACs/HPs could be enhanced to improve repeatability, 
representativeness, and accuracy, and reduce testing burden, and the 
proposals in this document are aimed at addressing those issues. 
Additionally, resolution of these issues has some urgency because the 
test procedure the proposals address is required to be used for testing 
starting on January 1, 2023. Hence, because DOE is aware that the test 
procedure could be improved to be more repeatable and representative, 
and less burdensome, a general early assessment process of request of 
comments, data, and information prior to the NOPR stage is not 
considered necessary.

II. Synopsis of the Notice of Proposed Rulemaking

    In this notice of proposed rulemaking (``NOPR''), DOE proposes to 
update appendix M1 to subpart B of part 430, ``Uniform Test Method for 
Measuring the Energy Consumption of Central Air Conditioners and Heat 
Pumps.'' DOE has identified certain provisions of appendix M1 that may 
benefit from additional detail and/or instruction. The proposed updates 
are as follows:
    (1) Adjusting the default fan power for two-stage coil-only systems 
when testing at low stage with reduced air volume rate to be more 
representative of fan input power trends as air volume rate reduces;
    (2) Defining ``Variable-speed Communicating Coil-only Central Air 
Conditioner or Heat Pump'' and ``Variable-speed Non-communicating Coil-
only Central Air Conditioner or Heat Pump'' and establishing procedures 
specific for testing such systems;
    (3) Allowing the adjustment of the air volume rate as a function of 
outdoor air temperature during testing for blower coil systems with 
either multiple-speed or variable-speed indoor fans and with a control 
system capable of adjusting air volume rate as function of outdoor air 
temperature;
    (4) Adjusting the maximum wet bulb temperature from 3 [deg]F to 4 
[deg]F for the H4 test condition;
    (5) Specifying in section 2(B) of appendix M1, that the 
instructions presented in the labels attached to the unit take 
precedence over the installation manuals printed and shipped with a 
product;
    (6) Specifying in sections 3.1.4.1.1, 3.1.4.1.2, and 3.1.4.4.3 of 
appendix M1 that the airflow measurement apparatus fan must be adjusted 
if necessary to maintain the same air volume rate for different test 
conditions for systems not including multiple-speed or variable-speed 
indoor fans with control system capability to adjust air volume rate as 
function of operating conditions such as outdoor air temperature; and
    (7) Revising the equations representing full-capacity operation of 
variable-speed heat pumps at and above 45 [deg]F ambient temperature to 
be consistent with the intent for nominal capacity operation.
    Additionally, in this notice of proposed rulemaking (``NOPR''), DOE 
proposes to update 10 CFR part 429, ``Certification, Compliance, and 
Enforcement for Consumer Products and Commercial and Industrial 
Equipment''. DOE has identified certain provisions of part 429 that may 
benefit from additional detail and/or instruction. The proposed updates 
are as follows:
    (1) Clarifying the language for required represented values for 
single-stage and two-stage coil-only CACs; and
    (2) Providing additional direction regarding the regional standard 
requirements in part 429.
    DOE's proposed substantive actions are summarized in Table II.1 
compared to the current test procedure as well as the reason for the 
proposed change (``attribution''). Additional proposed

[[Page 16833]]

incidental changes are summarized in Tables III-2 and III-3 in section 
III.C.10 of this document.

  Table II-1--Summary of Changes in Proposed Test Procedure Relative to
                         Current Test Procedure
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                                     Proposed test
  Current DOE test procedure           procedure           Attribution
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Calculate indoor fan power of   Calculate indoor fan    Improve
 two-stage coil-only CACs and    power of two-stage      representativen
 HPs using constant default      coil-only CACs and      ess.
 fan power values that do not    HPs for reduced air
 vary with air volume rate       volume rate tests
 (441W/1000 scfm for most two-   using new default fan
 stage coil-only CACs and HPs    power values air
 and 406 W/1000 scfm for         volume rate (360 W/
 mobile-home and space-          1000 scfm for most
 constrained CACs and HPs).      two-stage coil-only
                                 CACs and HPs and 331
                                 W/1000 scfm for
                                 mobile-home and space-
                                 constrained CACs and
                                 HPs).
No test procedure provisions    Test procedures and     Incorporate test
 for variable-speed, coil-only   requirements            procedures
 CACs and HPs.                   established for         contained in
                                 variable-speed coil-    test procedure
                                 only systems, include   waivers.
                                 new definitions for
                                 ``Variable-speed
                                 Communicating Coil-
                                 only Central Air
                                 Conditioner or Heat
                                 Pump'' and ``Variable-
                                 speed Non-
                                 communicating Coil-
                                 only Central Air
                                 Conditioner or Heat
                                 Pump'', for which the
                                 newly established
                                 test procedures have
                                 more flexibility.
Appendix M1 currently does not  For blower coil         Improve
 explicitly allow for            systems with multiple-  representativen
 variation of air volume rate    speed or variable-      ess for certain
 as outdoor temperature          speed indoor fans and   models.
 changes when testing blower     the control system
 coil systems.                   capability to adjust
                                 air volume rate as a
                                 function of outdoor
                                 air temperature,
                                 allow such air volume
                                 rate variation during
                                 testing.
Appendix M1 contains            Amend the wet bulb      Reduce test
 provisions for conducting an    test condition for      burden by
 optional H4 heating test at a   the H4 test to be 4     reducing the
 5 [deg]F outdoor ambient dry-   [deg]F maximum          time needed to
 bulb temperature and, at a      instead of the          remove
 maximum, a 3 [deg]F outdoor     current condition of    sufficient
 wet-bulb temperature.           3 [deg]F maximum.       moisture to
                                                         achieve the wet
                                                         bulb
                                                         requirement.
Clarification regarding which   Add direction to        Improve
 form of installation            prioritize the          representativen
 instructions to use, if         instructions            ess and
 multiple forms are provided,    presented in the        repeatability.
 only for VRF multisplit         label attached to the
 systems.                        unit over the
                                 installation
                                 instructions shipped
                                 with the unit for all
                                 CAC/HP products.
Appendix M1 currently is not    Add specific            Improve
 clear about how to achieve      instruction to adjust   representativen
 the same air volume rate for    the airflow             ess and
 different test conditions.      measurement apparatus   repeatability.
                                 fan but not the fan
                                 of the unit under
                                 test to achieve the
                                 same air volume rate
                                 for different tests.
The equations for full-         Revise the equations    Improve
 capacity operation for          for full-capacity       representativen
 variable-speed heat pumps at    operation at and        ess.
 and above 45 [deg]F ambient     above 45 [deg]F to be
 temperature are based on        more consistent with
 operating in this range with    compressor speed used
 a compressor speed the same     in normal operation
 as its operation in 17 [deg]F   for this temperature
 ambient temperature.            range, represented by
                                 the nominal heating
                                 test condition, H1N.
10 CFR part 429 provides        Reinforce the language  Improve clarity.
 requirements regarding          explaining regional
 regional CAC/HP efficiency      requirements.
 standards.
10 CFR 429.16(a)(1) provides    Modify the              Improve
 requirements for represented    instructions in that    repeatability.
 values of single-stage and      section to improve
 two-stage coil-only CACs that   clarity without
 can lead to different           changing meaning.
 interpretation.
10 CFR 430.2 defines central    Add exclusions for      Improved
 air conditioner, excluding      additional commercial   representativen
 two commercial package air-     package air-            ess.
 conditioning and heating        conditioning and
 categories--packaged terminal   heating categories
 air conditioners and packaged   that justifiably are
 terminal heat pumps.            not central air
                                 conditioners.
------------------------------------------------------------------------

    As mentioned previously, DOE is also fixing typographical errors in 
appendix M and appendix M1 that were commented upon by AHRI. DOE is 
addressing these issues in this rulemaking.
    Under 42 U.S.C. 6293(e)(1), DOE is required to determine whether an 
amended test procedure will alter the measured energy use of any 
covered product. If an amended test procedure does alter measured 
energy use, DOE is required to make a corresponding adjustment to the 
applicable energy conservation standard to ensure that minimally 
compliant covered products remain compliant. (42 U.S.C. 6293(e)(2)) DOE 
has tentatively determined that the proposed amendments described in 
section III of this NOPR would not alter the measured efficiency of 
CAC/HPs that are rated using the test procedure that is currently 
required for testing, i.e., appendix M. The proposals applicable for 
appendix M are simply fixing errors within the current test procedure. 
With respect to appendix M1, many of the proposals clarify test 
procedures rather than making changes that would affect the 
measurements. Variable-speed coil-only systems are not addressed 
currently in appendix M, so this proposal is establishing a method of 
test for those products. For two-stage coil-only systems, DOE is 
proposing to adjust the fan power to be more representative as further 
described in section X, which DOE believes will slightly improve the 
measured efficient of these combinations as compared to their current 
representative values. Given that two-sage combinations are not 
representative of minimally compliant combinations, DOE has tentatively 
determined that this proposal would not require an adjustment to the 
energy conservation standard for central air conditioners and heat 
pumps to ensure that minimally compliant central air conditioners and 
heat pumps would remain compliant. Additionally, DOE has tentatively 
determined that the proposed amendments, if made final, would not 
increase the cost of testing. Discussion of DOE's proposed actions are 
addressed in detail in section III of this NOPR.

[[Page 16834]]

III. Discussion

A. Scope of Applicability

    DOE is proposing to amend the test procedures at appendix M1 for 
CAC/HP and to implement a few minor clerical revisions to the test 
procedures at appendix M. A Central air conditioner or central air 
conditioner heat pump is defined as a product, other than a packaged 
terminal air conditioner or packaged terminal heat pump, which is 
powered by single phase electric current, air cooled, rated below 
65,000 British thermal units per hour (``Btu/h''), not contained within 
the same cabinet as a furnace, the rated capacity of which is above 
225,000 Btu/h, and is a heat pump or a cooling unit only. A central air 
conditioner or central air conditioning heat pump may consist of: A 
single-package unit; an outdoor unit and one or more indoor units; an 
indoor unit only; or an outdoor unit with no match. In the case of an 
indoor unit only or an outdoor unit with no match, the unit must be 
tested and rated as a system (combination of both an indoor and an 
outdoor unit). 10 CFR 430.2.
    Appendix M1 applies to the following CACs/HPs:
    (a) Split-system air conditioners, including single-split, multi-
head mini-split, multi-split (including VRF), and multi-circuit 
systems;
    (b) Split-system heat pumps, including single-split, multi-head 
mini-split, multi-split (including VRF), and multi-circuit systems;
    (c) Single-package air conditioners;
    (d) Single-package heat pumps;
    (e) Small-duct, high-velocity systems (including VRF);
    (f) Space-constrained products--air conditioners; and
    (g) Space-constrained products--heat pumps.
    See Section 1.1 of appendix M1.
    DOE is not proposing to change the scope of CACs/HPs covered by 
appendix M1.

B. Topics Arising From Test Procedure Waivers

1. Fan Power at Reduced Airflows for Coil-Only Systems
    Coil-only systems are indoor units that are distributed in commerce 
without an indoor blower or separate designated air mover. Such systems 
installed in the field rely on a separately installed furnace or a 
modular blower for indoor air movement. Because coil-only CAC/HPs do 
not include their own indoor fan to circulate air, the DOE test 
procedures prescribe equations that are used to calculate the assumed 
(i.e., ``default'') power input and heat output of an average furnace 
fan with which the test procedure assumes the indoor coil is pared in a 
field installation. The resulting fan power input value is added to the 
electrical power consumption measured during testing. The resulting fan 
heat output value is subtracted from the measured cooling capacity of 
the CAC/HP for cooling mode tests and added to the measured heating 
capacity for heating mode tests. In appendix M1, separate fan power and 
fan heat equations are provided for different types of coil-only 
systems (i.e., the equations for mobile home or space-constrained are 
different than for ``conventional'' non-mobile home and non-space-
constrained). In each equation, the measured airflow rate (in cubic 
feet per minute of standard air (``scfm'')) is multiplied by a defined 
coefficient (expressed in Watts (``W'') per 1,000 scfm (``W/1000 
scfm'') for fan power, and British Thermal Units (``Btu'') per hour 
(``Btu/h'') per 1,000 scfm (``Btu/h/1000 scfm'') for fan heat), 
hereafter referred to as the ``default fan power coefficient'' and 
``default fan heat coefficient.''
    In appendix M, the default fan power coefficient is defined as 365 
W/1000 scfm, and the default fan heat coefficient is defined as 1,250 
Btu/h/1000 scfm.\5\ (appendix M, section 3.3.d). For testing of two-
stage coil-only systems, appendix M requires testing at two load 
conditions: (1) Full-load, operating at full compressor stage, and (2) 
low-load (also referred to as part-load), operating at the lower 
compressor stage. The test procedure defines the relative air volume 
rates to use for each test; in general, the part-load test has a lower 
air volume rate than the full-load test.\6\ For both the default fan 
power coefficient and default fan heat coefficient, the same 
coefficient is used for both the full-load and part-load tests.\7\
---------------------------------------------------------------------------

    \5\ For example, for a CAC/HP test conducted at an airflow rate 
of 1640 scfm, the default fan power would be calculated as (365 W/
1000 scfm x 1,640 scfm = 599 W); and the default fan heat would be 
calculated as (1,250 Btu/1000 scfmh x 1,640 scfm = 2,050 Btu/h).
    \6\ Specifically, the indoor air volume rate to be used for 
testing at part-load (i.e., the ``cooling minimum air volume rate'') 
is the higher of (1) the rate specified by the installation 
instructions included with the unit by the manufacturer, or (2) 75 
percent of the cooling full-load air volume rate (see section 
3.1.4.2.c of appendix M).
    \7\ For example, for a two-stage coil-only system that has a 
cooling full-load air volume rate of 1,640 scfm and a cooling 
minimum (i.e., part-load) air volume rate of 1,230, the default fan 
power at full load would be calculated as (365 W/1000 scfm x 1,640 
scfm = 599 W); and default fan power at part-load would be 
calculated as (365 W/1000 scfm x 1,230 scfm = 449 W).
---------------------------------------------------------------------------

    The January 2017 Final Rule adopted certain values in appendix M1 
to be more representative of field conditions, as compared to appendix 
M (i.e., consistent with indoor fan power consumption at the increased 
minimum required external static pressures defined in appendix M1). 82 
FR 1426, 1451-1453. Specifically, appendix M1 defines separate default 
fan power coefficients and default fan heat coefficients for coil-only 
systems intended for installation in mobile-home applications and for 
space-constrained systems, as opposed to those intended for all other 
``conventional'' applications. Id. Specifically, for coil-only units 
installed in mobile-home and space-constrained systems, appendix M1 
defines a default fan power coefficient of 406 W/1000 scfm and a 
default fan heat coefficient of 1,385 Btu/h/1000 scfm. For coil-only 
units installed in conventional (i.e., non-mobile-home and non-space-
constrained) systems, appendix M1 defines a default fan power 
coefficient of 441 W/1000 scfm and a default fan heat coefficient of 
1,505 Btu/h/1000 scfm. (10 CFR part 430, subpart B, appendix M1, 
section 3.3.d). As with appendix M, in appendix M1, for both the 
default fan power coefficient and default fan heat coefficient, the 
same coefficient is used for both the full-load and part-load tests.
    In updating the default fan power coefficients and default fan heat 
coefficients for coil-only systems in appendix M1, DOE relied on indoor 
fan electrical power consumption data collected from product 
literature, testing, and exchanges with manufacturers during a previous 
furnace fan rulemaking (see 79 FR 500, 506; Jan. 3, 2014) to determine 
appropriate values for these coefficients for coil-only products. 80 FR 
69277, 69318.
    By letter dated September 7, 2021, Nortek filed a petition for 
waiver and interim waiver from the test procedure for CAC/HPs set forth 
in appendix M1.\8\ Specifically, Nortek requested waivers for basic 
models of ducted, coil-only, two-stage CAC/HPs. Nortek asserted that 
appendix M1 contains errors in the calculations for capacity adjustment 
and power consumption for the indoor fan at part-load conditions 
resulting from a faulty assumption of default fan wattage at reduced 
airflows. (Nortek, EERE-2021-BT-WAV-0025, No. 1 at p. 1) Nortek 
asserted that by applying the same default fan power coefficient and 
default fan heat coefficient to both the full-load and part-load tests, 
appendix M1 incorrectly establishes a linear

[[Page 16835]]

relationship between indoor airflow and fan power (and fan heat); 
whereas, according to Nortek, a cubic relationship should be applied 
instead, citing the theoretical fan affinity laws that describe the 
relationship between fan power and airflow. (Nortek, EERE-2021-BT-WAV-
0025, No. 1 at p. 2) Nortek recommended an alternate test procedure 
that would define lower default fan power coefficients and default fan 
heat coefficients for the part-load tests, instead of applying the same 
coefficients to both the full-load and part-load tests, as is done in 
appendix M1. (Nortek, EERE-2021-BT-WAV-0025, No. 1 at pp. 4-9)
---------------------------------------------------------------------------

    \8\ As noted, appendix M1 is the test procedure applicable to 
CAC/HPs beginning January 1, 2023.
---------------------------------------------------------------------------

    On November 16, 2021, DOE published a notification that announced 
its receipt of the petition for waiver and denial of Nortek's petition 
for an interim waiver. 86 FR 63357 (``Notification of Petition for 
Waiver''). In the Notification of Petition for Waiver, DOE noted that 
applying the modified default fan power coefficients and default fan 
heat coefficients in appendix M1 to products such as those that are the 
subject of Nortek's petition was determined to be representative of the 
systems' performance and reflected the adoption of the recommendations 
of a working group formed to negotiate a notice of proposed rulemaking 
for energy conservation standards for CAC/HPs; and that the modified 
coefficients were subject to public comment during the 2016 test 
procedure rulemaking for CAC/HPs. 82 FR 1426, 1452 (January 5, 2017). 
DOE also noted that Nortek commented in support of the modified 
coefficients during the 2016 rulemaking. Id.
    In response to the issue raised by Nortek, DOE re-examined the 
furnace fan electrical power consumption data collected for the furnace 
fans rulemaking (see 79 FR 506, Jan. 3, 2014) that was used to develop 
the default fan power coefficients and default fan heat coefficients 
for coil-only products in appendix M1. In establishing the current 
coefficients, for each furnace fan in DOE's furnace fan dataset, DOE 
developed correlations of airflow and power consumption as functions of 
external static pressure (``ESP''), and then applied those correlations 
to a reference ductwork system curve to predict the actual operating 
airflow and power consumption at each fan speed setting for the furnace 
fan.
    DOE has extended the prior analysis to examine both full-load and 
part-load air volume rates.\9\ DOE correlated the predicted power 
consumption with the predicted air volume rate for each furnace fan to 
determine adjusted values of the default fan power coefficients that 
may result in a more representative estimate of fan power and fan heat 
at reduced airflow conditions, compared to the coefficients currently 
defined in appendix M1. DOE's analysis indicates that at a reduced air 
volume rate of 75 percent, the average indoor fan power coefficient 
would be 360 W/1000 scfm for coil-only CAC/HPs in a conventional (i.e., 
non-mobile-home and non-space-constrained) installation. For mobile-
home and space-constrained systems, to the average indoor fan power 
coefficient would be 331 W/1000 scfm. DOE also calculated the 
associated fan heat coefficients associated with these power input 
levels. The average indoor fan heat coefficients would be 1,228 Btu/hr/
1000 scfm and 1,130 Btu/h/1000 scfm for conventional (i.e., non-mobile-
home and non-space-constrained) and mobile-home/space-constrained 
installations, respectively.
---------------------------------------------------------------------------

    \9\ To ensure consistency across analyses, DOE aggregated the 
data by applying market weightings to each type and brand of furnace 
model, using the same market shares that were used in the previous 
analysis for the 2016 CAC TP Rulemaking.
---------------------------------------------------------------------------

    The analysis conducted by DOE resulted in higher default fan power 
coefficients and default fan heat coefficients at the reduced 75 
percent air volume rate than the values presented in the Nortek waiver 
petition. DOE tentatively concludes that its analysis is a more 
appropriate representation of average furnace fan power consumption 
than the results presented by Nortek for the following reasons: (1) 
DOE's analysis relied on test and specification data from a collection 
of actual furnaces operating at reduced air volume rates, whereas the 
Nortek analysis derived default fan power values using a theoretical 
relationship between full-load and part-load conditions; (2) DOE's 
analysis applied the same weighting factors that were used to develop 
the full-load default values during the 2016 CAC TP Rulemaking, whereas 
Nortek's analysis introduced new weighting factors and motor efficiency 
data without indicating the source of the data; and (3) DOE's analysis 
considered performance data from an additional type of fan motor not 
considered by Nortek (specifically, constant-torque brushless-
permanent-magnet ``X13'' motors). Therefore, in this NOPR DOE proposes 
to amend the default fan power coefficients and default fan heat 
coefficients for coil-only fan power when operating at reduced air 
volume rates to reflect the results of its analysis. Specifically, when 
operating at 75 percent air volume rate (or higher manufacturer-
specified air volume rate that is between the 75 percent air volume 
rate and the full-load air volume rate as described in appendix M1, 
section 3.1.4.2.c), DOE proposes to specify for ducted two-capacity 
coil-only systems a default fan power coefficient of 360 W/1000 scfm 
and a default fan heat coefficient of 1,228 Btu/h/1000 scfm for units 
installed in conventional systems; and a default fan power coefficient 
of 331 W/1000 scfm and a default fan heat coefficient of 1,130 Btu/h/
1000 scfm for mobile home and space-constrained systems.\10\
---------------------------------------------------------------------------

    \10\ For example, under DOE's proposed changes to Appendix M1, 
for a two-stage coil-only system in a conventional application that 
has a cooling full-load air volume rate of 1,640 scfm and a cooling 
minimum (i.e., part-load) air volume rate of 1,230, the default fan 
power at full load would be calculated as (441 W/1000 scfm x 1,640 
scfm = 723 W); and default fan power at part-load would be 
calculated as (371 W/1000 scfm x 1,230 scfm = 456 W).
---------------------------------------------------------------------------

    The reduced air volume rate used for low-stage operation of two-
stage coil-only systems may be higher than 75 percent of the full-load 
air volume rate, if the manufacturer's instructions specify a higher 
part-load air volume rate. DOE is proposing that in such cases, the 
default fan power values associated with full-load air volume rate be 
used. However, the appropriate default fan power coefficient and 
default fan heat coefficient may be values between the reduced values 
discussed above and the values used for full-load air volume rate. For 
such cases, DOE could consider alternative options, other than 
requiring use of the full-load air volume default fan power and fan 
heat coefficients. Two alternative options include (1) allowing the 
reduced value up to a threshold value, e.g., 80 percent of full-load 
air volume rate, above which the full-load value would be required, and 
(2) requiring a linear interpolation of the default fan power 
coefficient between the reduced value at 75 percent of full-load air 
volume rate to the full-load value at 100 percent.\11\ DOE seeks 
comment on whether one these alternate approaches should be adopted 
instead of the proposed use of the single reduced coefficients for the 
category discussed previously.
---------------------------------------------------------------------------

    \11\ For example, for non-mobile-home and non-space-constrained 
systems, if a linear interpolation of the default fan power 
coefficient is required, it would be equal to 371 + (441-
371)*(%FLAVR-75%)/(100%-75%), where %FLAVR is the reduced air volume 
rate used for the test expressed as a percentage of the full load 
air volume rate.
---------------------------------------------------------------------------

    DOE requests comment on its proposal to specify a reduced default 
fan power coefficient and default fan heat coefficient at part-load 
airflows in the calculations of SEER2 and HSPF2

[[Page 16836]]

for ducted two-stage coil-only systems. DOE requests comment on the 
specific default fan power coefficients and default fan heat 
coefficients proposed. If the proposed values are not appropriate, DOE 
seeks data to support selection of alternative values. Additionally, 
DOE requests comment on whether a single default fan power coefficient 
(and default fan heat coefficient) should be used for each product 
class group regardless of the actual air volume rate used for low-stage 
tests, or whether one of the alternative approaches discussed in the 
NOPR should be considered, or any other alternative. DOE also requests 
comment on whether any two-stage systems use a part-load air volume 
rate higher than 75 percent of the full-load air volume rate, and if 
so, whether the ratio is a value less than 100 percent.
2. Variable-Speed Coil-Only Test Procedure
    As discussed, appendix M1 contains provisions for testing split-
system CAC/HPs equipped with ``coil only'' indoor units that, in a 
field installation, are paired with an existing furnace or other air 
handler in order to circulate conditioned air through ductwork. These 
provisions apply to single-stage and two-stage systems.\12\ appendix M1 
does not include provisions for testing variable-speed systems equipped 
with coil-only indoor units.
---------------------------------------------------------------------------

    \12\ Section 3.1.4.2 (cooling minimum air volume rate), section 
3.1.4.3 (cooling intermediate air volume rate), and section 3.1.4.6 
(heating intermediate air volume rate) of appendix M1.
---------------------------------------------------------------------------

    Since the publication of the January 2017 Final Rule, DOE has 
granted test procedure waivers to GD Midea Heating & Ventilating 
Equipment Co., Ltd. (``GD Midea'') (83 FR 56065 (Nov. 9, 2018)) and TCL 
air conditioner (zhongshan) Co. Ltd. (``TCL AC'') (84 FR 11941 (Mar. 
29, 2019)), and an interim waiver for LG Electronics U.S.A., Inc. 
(``LGE'') (85 FR 40272 (July 6, 2020)), for specified basic models of 
variable-speed, coil-only CAC/HPs. In each of these cases, the 
petitioners identified their variable-speed coil only systems as ``non-
communicative'' systems for which compressor speed varies based only on 
controls located on the outdoor unit, and for which the indoor unit 
maintains a constant indoor blower fan speed (see, e.g., 83 FR 24767, 
24769 (May 30, 2018)). As required under the specified alternate test 
procedures, the subject systems must be tested according to the 
appendix M provisions applicable to variable-speed systems (e.g., three 
different compressor speeds in the cooling mode), except that the 
subject systems must be tested using the full-load cooling air volume 
rate at all test conditions, commensurate with the constant indoor 
blower fan speed that these units would experience (GD Midea, EERE-
2017-BT-WAV-0060, No. 1, pp. 1-3; TCL, EERE-2018-BT-WAV-0013, No. 1, 
pp. 2-4; LG, EERE-2019-BT-WAV-0023, No. 1, pp 3-4). DOE notes that the 
waivers for these models were granted for appendix M only and will 
expire on Jan 1, 2023--the date when use of appendix M1 becomes 
required for any representations, including compliance certifications, 
made with respect to the energy use, power, or efficiency of CAC/HPs.
    DOE notes also that the waivers for ``non-communicative'' variable-
speed coil-only systems did not address comprehensively how the outdoor 
units are controlled to turn on or off in cooling mode or in heating 
mode, nor how the compressor speeds are set to match the internal 
building load. Regarding the latter, the waivers indicated only that 
``compressor speed varies based only on controls located on the outdoor 
unit'' (GD Midea, EERE-2017-BT-WAV-0060, No. 1, p. 6; TCL, EERE-2018-
BT-WAV-0013, No. 1, p. 4; LG, EERE-2019-BT-WAV-0023, No. 1, pp 2). DOE 
did not receive information in the waiver petitions regarding, nor has 
it evaluated, the compressor speed selections used for different test 
conditions specified in appendix M or appendix M1. Further, DOE has not 
compared these speed selections with those used by blower-coil variable 
speed systems for the same test conditions. Based on the information 
received and evaluated, DOE has yet to receive sufficient evidence that 
can be relied on to conclude that the alternate test procedures 
specified in the waivers are representative of average use cycles of 
CAC/HPs other than those subject to the granted waivers, as required by 
EPCA for DOE test procedures.
    DOE has also granted an interim test procedure waiver to Goodman 
Manufacturing Company, L.P. (``Goodman'') (86 FR 40534 (July 28, 2021)) 
for their basic models of variable-speed, coil-only CAC/HPs. Unlike the 
aforementioned test procedure waivers, Goodman represented, and 
supported in their petition, that their systems have communicative 
controls, where both the outdoor unit and indoor coil communicate with 
each other to control both the variable-speed compressor and multi-
speed indoor fan. 86 FR 40534, 40539. As a result, the alternate test 
procedure prescribed under the interim waiver requires use of two 
different indoor air volume rates during testing to simulate the 
impacts of communicative control that would be realized in a typical 
field installation. 86 FR 40534, 40538. Specifically, the Goodman 
waiver requires use of the cooling full-load air volume rate for the 
full-load cooling and full-load heating tests; and the cooling minimum 
air volume rate for the cooling minimum, heating minimum, cooling 
intermediate, and heating intermediate tests. Id.
    In response to the notice of petition for waiver, Rheem questioned 
the approach of the alternate test procedure in specifying two 
different indoor air volume rates during testing of these basic models. 
(Rheem, EERE-2021-BT-WAV-0001, No. 7 at p. 1). Rheem expressed concern 
that the alternate test procedure would allow Goodman an unfair 
competitive advantage, (i.e., by allowing reduced airflow rates at low-
load test conditions while other variable-speed coil-only products 
would be required to test at full-load cooling air volume rate for all 
test conditions), that it would be unlikely that installers would 
correctly install the communicative products to enable the indoor fan 
control requested in Goodman's proposed alternate test procedure, and 
that most furnace fans currently installed are not capable of adding 
controls to set multiple airflow rates. In response to the Rheem 
comment, Goodman stated that almost all two-stage coil-only ratings 
today utilize a lower indoor air volume rate for low-stage compressor 
operation, and highlighted training procedures and other best-practices 
put in place to ensure proper installation of communicating systems. 
(Goodman, EERE-2021-BT-WAV-0001, No. 8 at pp. 1-4)
    As stated in a final rule published in 2005, use of a lower air 
volume rate for low-stage operation is based on the assumption that the 
two-capacity coil-only unit would most often be used with an existing 
multi-tap furnace blower (i.e., a furnace fan capable of multiple 
speeds). 70 FR 59122, 59128 (October 11, 2005). The two-stage coil-only 
test provisions in the DOE test procedure are premised on the 
installation location having two-stage thermostat wiring (Final Rule 
Technical Supporting Document, EERE-2014-BT-STD-0048, No. 98, p. 8-25). 
DOE similarly assumes the presence of the necessary wiring for the 
installation of variable-speed systems.
    As mentioned in the notification of the interim waiver issued in 
response to the Goodman petition, DOE reviewed numerous materials 
relevant to the control of the Goodman variable-speed coil-only system, 
including additional materials Goodman provided in support of the 
petition. 86 FR 40534, 40537 (July

[[Page 16837]]

28, 2021). These materials included installation manuals and other 
information that confirmed similarities between the system's control 
and the control of more conventional variable-speed blower-coil systems 
(including the use of communicating controls), providing justification 
for claims that the alternate test procedure specified in the waiver 
would be representative of average use.
    DOE notes that Goodman's interim waiver was granted for both 
appendix M and appendix M1. The waiver for appendix M will expire on 
the date representations are required to be based on testing according 
to appendix M1 (Jan 1, 2023), and the waiver for appendix M1 will 
expire on the date on which use of an amended test procedure that 
addresses the issues presented in the Goodman waiver is required to 
demonstrate compliance. 10 CFR 430.27(h)(3).
    In this NOPR, DOE proposes to add testing provisions addressing 
variable-speed coil-only systems in appendix M1. DOE also proposes to 
define ``communicating control'' in the context of variable-speed, 
coil-only CAC/HPs in order to differentiate between the test procedure 
provisions that would be applicable to communicating systems from those 
applicable to non-communicating systems.
    DOE is proposing provisions as generally prescribed in the relevant 
waivers, except that DOE is proposing to require that all variable-
speed coil-only systems, regardless of communicative capability, would 
be tested using the cooling minimum air volume rate for the cooling 
minimum, heating minimum, cooling intermediate, and heating 
intermediate tests. This proposal is consistent with the conditions 
specified in the interim waiver granted to Goodman. DOE further 
proposes to require that non-communicative variable-speed coil-only 
systems be tested using the newly proposed provisions for variable-
speed compressor with non-communicating coil-only systems (i.e., 
eliminating the EV test for cooling and H2V for 
heating as well as including H22, H21 and 
H31 for heating), whereas systems that meet the newly 
proposed criteria for ``communicating'' control would follow the 
existing variable-speed test procedure.
    Regarding indoor air volume rate, the proposed test procedure would 
utilize the same procedure as for ducted two-capacity coil-only units. 
As discussed previously, the two-stage coil-only test procedure is 
premised on the capability of controlling an existing multi-tap furnace 
fan at two air volume rates for cooling operation. DOE is not proposing 
to amend this approach. DOE is proposing to apply a similar approach to 
the testing of variable-speed coil-only systems. As such, DOE proposes 
to align the requirements for minimum air volume rate between two-
capacity and variable-speed coil-only indoor units, regardless of 
communicating capabilities. This includes adopting the reduced default 
fan power and default fan heat coefficients at reduced air volume rates 
discussed in section I.B.1. However, if the system does not include the 
capability to control an existing furnace fan at two air volume rates, 
the manufacturer has the option of specifying minimum/intermediate air 
volume rates equal to the full-load air volume rate. Regarding 
compressor speed, the proposed test procedure would limit use of the 
variable-speed testing provisions to those systems meeting the newly 
proposed criteria for communicating control.
    As previously stated, the test procedure for two-stage coil-only 
systems is premised on the system using a two-stage thermostat and 
associated wiring that responds to indoor temperature measurements and 
sends voltage signals that enable two-stage control of both the 
compressor speed and the indoor fan speed. A more sophisticated control 
approach is required to enable a variable speed system to modulate 
compressor speed control (e.g., proprietary thermostat, serial 
communication wiring, and/or electronic sensors at the indoor coil). 
DOE proposes to define ``Communicating Variable-speed Coil-only Central 
Air Conditioner or Heat Pump'' in section 1.2 of appendix M1 to 
distinguish variable-speed coil-only systems with such control as the 
following:
    Variable-Speed Communicating Coil-Only Central Air Conditioner or 
Heat Pump means a variable-speed compressor system having a coil-only 
indoor unit that is installed with a control system that (a) 
communicates the difference in space temperature and space setpoint 
temperature (not a setpoint value inferred from on/off thermostat 
signals) to the control that sets compressor speed; (b) provides a 
signal to the indoor fan to set fan speed appropriate for compressor 
staging and air volume rate; and (c) has installation instructions 
indicating that the required control system meeting both (a) and (b) 
must be installed.
    DOE also proposes to define variable-speed systems that do not have 
this communicating feature as the following:
    Variable-Speed Non-communicating Coil-Only Central Air Conditioner 
or Heat Pump means a variable-speed compressor system having a coil-
only indoor unit that does not meet the definition of variable-speed 
communicating coil-only central air conditioner or heat pump.
    Variable-speed coil-only systems that meet the ``communicating'' 
definition would be tested like any other variable-speed system, except 
that the heating full-load air volume rate would be equal to the 
cooling full-load air volume rate, and the intermediate and minimum 
cooling and heating air volume rates would all be the higher of (1) the 
rate specified by the installation instructions included with the unit 
by the manufacturer, and (2) 75 percent of the full-load cooling air 
volume rate.
    DOE proposes that those variable-speed coil-only systems that are 
not ``communicating'' as defined above would be tested with additional 
limitations as if they have some variable-speed system characteristics 
and some two-stage coil-only system characteristics. Specifically, (a) 
the outdoor unit and/or the indoor unit would be provided with a 
control signal indicating operation at high or low stage, rather than 
testing with compressor speed fixed at specified speeds, and (b) air 
volume rates would be determined consistent with the requirement for 
two-stage coil-only systems. A key implication of (a) is that there 
would be no intermediate compressor speed operation. Many of the 
requirements associated with variable-speed operation would, however, 
be retained. For example, such systems would be allowed to have 
``minimum speed-limiting'' control for heat pump mode (see the 
alternative calculations representing minimum-speed operation in 
appendix M1, section 4.2.4.b). The test method for non-communicating 
variable-speed coil-only systems would include requiring tests for 
minimum-speed operation for both the 35 [deg]F and 17 [deg]F heating 
test conditions so that the HSPF2 calculations utilize test results for 
appropriate compressor speeds. Also, the full compressor speed during 
heating mode operation would be allowed to vary with outdoor 
temperature, there would be an H1N test to represent the 
nominal capacity, and the same provisions for calculation of full-speed 
capacity and power applied to conventional variable-speed systems would 
be used (see, e.g., the calculations in appendix M1, sections 3.6.4, 
4.2.4.c, and 4.2.4.d). If a manufacturer chooses to run the optional 
H12 test (i.e. if compressor speed for the H1N 
test is different than compressor speed for the H32 test, 
and

[[Page 16838]]

the manufacturer chooses to run the H12 test rather than use 
the standardized slope factors described in appendix M1 section 
3.6.4.b), then the test would be run with over-ride of compressor speed 
using the same speed as used for the H32 test--this is the 
only test for which such over-ride would be allowed.
    To ensure consistency of testing, it may be necessary for 
manufacturers to certify whether a variable-speed coil-only rating is 
based on non-communicating or communicating control. However, this 
change is not being proposed in this NOPR and may be considered in a 
separate rulemaking.
    DOE requests comment on its proposals related to test procedures 
for variable-speed coil-only CAC/HPs and on its proposed definitions 
for variable-speed communicating and non-communicating coil-only CAC/
HPs.
    DOE recognizes that there may be variable-speed control technology 
that cannot be tested according to the proposed test approach described 
previously for non-communicating variable-speed coil-only systems. 
Specifically, the test approach may not result in tests that meet the 
stability requirements for testing (i.e., the measurements might not 
meet the tolerance requirements in Table 2 of ANSI/ASHRAE 37-2009, 
``Methods of Testing for Rating Electrically Driven Unitary Air-
Conditioning and Heat Pump Equipment,'' (``ASHRAE 37-2009''), which is 
incorporated by reference by the DOE test procedure). Or the proposed 
test procedure might evaluate such a basic model in a manner so 
unrepresentative of its true energy consumption characteristics as to 
provide materially inaccurate comparative data. In this case, the 
manufacturer may petition DOE for a waiver and include a suggested 
alternate test procedure. See 10 CFR 430.27. As part of its review of 
such a waiver and alternate test procedure, DOE would consider the 
correlation between results of a suggested alternate test procedure and 
results of testing when using the two-stage two-wire controls expected 
to be available in a general coil-only system installation, recognizing 
that the latter testing may involve dynamics that exceed the 
measurement tolerances discussed above. DOE would also consider the 
control hardware involved in achieving appropriate control for indoor 
and outdoor conditions and some understanding of how the control works.
    DOE is aware that installations using non-communicating controls 
may not be limited only to variable-speed coil-only systems, but could 
also occur with variable-speed blower-coil systems. DOE's proposal 
makes a distinction between the testing approach used for coil-only 
configurations and the testing approach used for blower-coil 
configurations. As coil-only installations are much more likely than 
blower-coil installations to involve use of both the existing furnace 
fan and existing controls, the test procedure should be reflective of 
coil-only installations because they are more representative than 
blower coil installations.
    DOE has considered whether the current test procedures for 
variable-speed systems generally give manufacturers too much 
flexibility in specifying fixed settings of the compressor and indoor 
fan for testing without requiring the selected settings to be 
demonstrated using native control testing. DOE is well aware that there 
is ongoing work addressing questions about whether the current DOE test 
procedure for variable-speed systems is fully representative of native 
control operation. However, DOE has initiated this rulemaking not as a 
comprehensive revision that will satisfy the 7-year lookback 
requirements (see 42 U.S.C. 6293(b)(1)(A)), but instead as an action 
that will address a focused group of known issues, including those that 
have been raised through the test procedure waiver process. Thus, DOE 
is limiting its proposals addressing potential concerns about variable-
speed systems to coil-only systems, for which there are clear 
differences in system controls architecture, particularly when using 
non-communicating controls, which impact the performance of these 
systems in the field. However, DOE may more comprehensively address 
these issues for all variable-speed systems in a future rulemaking.
Coil-Only Variable-Speed System Representations and Testing
    Coil-only testing approaches for variable-speed systems address the 
installation of variable-speed technology in which the newly-installed 
system uses existing components, for example an existing furnace fan. 
For single-capacity and two-capacity air-conditioners, certification 
requirements anticipate this potential gap by requiring that such 
models include performance representations with a coil-only combination 
representative of the least-efficient combination in which the outdoor 
unit is sold (see 10 CFR 429.16(a)(1)). DOE considered whether such a 
requirement may be appropriate for variable-speed systems.
    A review of manufacturing materials, such as product datasheets and 
installation instructions, indicates that there is a wide range of 
instruction provided regarding the need to pair a variable-speed 
outdoor unit with specific models of indoor units and/or air movers 
(e.g., furnaces) whose controls can be coordinated with those of the 
outdoor unit to optimize performance. Some literature is very clear 
that achieving the rated performance requires installation with 
specific models of mating components with variable-speed indoor fans 
and communicating controls. However, other models have literature that 
does not mention the need for such pairing of components. The latter 
group is not limited to brands that have received test procedure 
waivers or interim waivers for variable-speed coil-only systems. Thus, 
it is possible that variable-speed systems are being installed in coil-
only applications for which the system representations may not be 
representative of actual performance because the representations are 
blower-coil based. Realizing this possibility, DOE considered the 
approaches that could be applied to address this issue.
    Currently, every single-split system AC with other than single-
stage and two-stage compressors must represent every individual 
combination distributed in commerce, including all coil-only and blower 
coil combinations. 10 CFR 429.16(a)(1). These regulations, when 
combined with the test procedure proposals in this NOPR, would require 
manufacturers to represent variable-speed ACs based on how they 
distribute them in commerce, which includes whether they are coil-only 
communicating, coil-only noncommunicating, or blower coil, as 
applicable to a given model of outdoor unit. DOE would evaluate how 
manufacturers distribute models of outdoor units based on review of 
product datasheets, installation and operation manuals, product 
marketing, relevant databases (including the AHRI database), 
manufacturer websites, and other related materials that help inform the 
consumer how the outdoor unit should be installed.
    As noted previously, representations of efficiency for single-split 
air conditioners with a single-stage or two-stage compressor must 
include at least one coil-only combination representative of the least-
efficient combination distributed in commerce with that outdoor unit. 
10 CFR 429.16(a)(1). As part of this rulemaking, DOE considered 
adopting such an approach for all single-split outdoor units, including 
variable speed models, to ensure that representations include all 
installations that may occur in the field. However, based on the

[[Page 16839]]

information DOE has from the previous energy conservation standards 
rulemaking pertaining to central air conditioners and heat pumps, less 
than 5 percent of variable-speed system installations are coil-only 
installations. 82 FR 1786. Further, the number of certified 
combinations of variable-speed coil-only systems is a small percentage 
of all of the variable-speed system certifications.\13\ Based on this 
information, DOE concludes that installations of variable-speed systems 
in coil-only applications are not likely to be representative of 
variable-speed system operation as a whole. For this reason, DOE is not 
proposing a blanket coil-only representation requirement for variable-
speed systems. However, DOE may revisit this possibility if it 
determines that there is significant distribution in commerce of coil-
only variable-speed systems using outdoor units that do not include a 
coil-only representation.
---------------------------------------------------------------------------

    \13\ For example, there are roughly 27,000 combinations listed 
in the AHRI Database for which a non-zero intermediate indoor air 
volume rate is listed, indicating that the combination is a 
variable-speed model. DOE reviewed the current certifications in the 
certification compliance management system and found that there are 
approximately 400 variable-speed coil-only combinations, 
representing roughly 1.5 percent of the total variable speed 
combinations certified to the Department.
---------------------------------------------------------------------------

    In order improve representativeness of the representations of 
variable-speed systems used in coil-only combinations, DOE proposes to 
require a coil-only tested combination for any variable-speed outdoor 
unit distributed in commerce in a coil-only combination. In addition, 
DOE proposes to require that, if a manufacturer distributes in commerce 
an outdoor unit basic model with other than a single-stage or two-stage 
compressor in non-communicating coil-only combinations, the combination 
selected for testing be a non-communicating coil-only combination. If a 
manufacturer distributes in commerce an outdoor unit basic model with 
other than a single-stage or two-stage compressor only in communicating 
coil-only combinations, then the combination selected for testing that 
outdoor model would be a communicating coil-only combination. Finally, 
if the manufacturer does not distribute in commerce any coil-only 
combinations, then the individual combination selected for testing for 
split-system AC and HP with other than a single-stage or two-stage 
compressor would be a blower-coil combination.
    DOE notes that the variable-speed coil-only waiver petitions 
addressed both air-conditioners and heat pumps. Thus, DOE's considered 
whether the coil-only tested combination requirement should apply to 
variable speed heat pumps and/or to single-stage and/or two-stage heat 
pumps. DOE notes that coil-only heat pumps allow the heating system to 
provide heat either using the furnace or the heat pump. There has been 
greater interest in such systems in recent years, since they provide 
heating with a furnace in extreme cold conditions for which a heat pump 
may have limited capacity and/or reduced efficiency.\14\ DOE is 
proposing in this NOPR to require coil-only tested combinations for 
variable-speed heat pumps, but not for single- and two-stage heat 
pumps, because DOE expects that the representativeness of blower-coil 
tests would deviate more from coil-only tests for variable-speed 
systems, due to the use of a variable-speed indoor fan and use of an 
intermediate air volume rate used for intermediate-speed testing for 
variable-speed systems. The test procedures for single-stage and two-
stage heat pumps are more restrictive with regard to allowed air volume 
rates and thus performance differences between blower-coil and coil-
only operation would be less.
---------------------------------------------------------------------------

    \14\ https://www.trane.com/residential/en/resources/glossary/dual-fuel-heat-pump/(last accessed 2/4/2022).
---------------------------------------------------------------------------

    Regarding variable-speed coil-only systems using indoor units 
manufactured by independent coil manufacturers (``ICMs''), the 
regulations require certification of the performance of any variable-
speed coil-only combinations distribution in commerce, and whether any 
given combination is coil-only (see 10 CFR 429.16(a)(1)). However, DOE 
notes that a tested combination for an ICM indoor unit must include the 
least-efficient outdoor unit with which the indoor unit is distributed 
in commerce (see 10 CFR 429.6(b)(2)(i)). DOE does not believe any 
changes are needed to this proposal with respect to ICM certifications 
as the current regulations already encompass representing all 
combinations distributed in commerce, including noncommunicating and 
communicating variable-speed coil only systems.
    DOE requests comment on its approach for variable speed coil-only 
systems. More specifically, DOE seeks comment on its proposal to 
require coil-only tested combinations for variable-speed systems, both 
air-conditioners and heat pumps, that are distributed in commerce with 
coil-only combinations. DOE also requests comment on the proposal to 
require that the tested combination be a non-communicating coil-only 
combination, if the outdoor unit is distributed in commerce in a non-
communicating coil-only combination.
3. Space-Constrained Coil-Only CAC Ratings
    DOE's regulations at 10 CFR 429.16 prescribe certification 
requirements for CAC/HPs. Paragraph (a)(1) of that section includes a 
table specifying the required represented values for each ``tested 
combination'' of CAC/HPs. Table III-1 is an excerpt from the table in 
10 CFR 429.16(a)(1) showing represented value requirements for 
different varieties of split-system CAC/HPs.

    Table III-1--Required Represented Values for Split-System CAC/HPs
                      [Excerpted from 429.16(a)(1)]
------------------------------------------------------------------------
                                    Equipment       Required represented
           Category                subcategory             values
------------------------------------------------------------------------
Outdoor Unit and Indoor Unit    Single-Split-      Every individual
 (Distributed in Commerce by     System AC with     combination
 OUM).                           Single-Stage or    distributed in
                                 Two-Stage          commerce must be
                                 Compressor         rated as a coil-only
                                 (including Space-  combination. For
                                 Constrained and    each model of
                                 Small-Duct, High   outdoor unit, this
                                 Velocity Systems   must include at
                                 (SDHV)).           least one coil-only
                                                    value that is
                                                    representative of
                                                    the least efficient
                                                    combination
                                                    distributed in
                                                    commerce with that
                                                    particular model of
                                                    outdoor unit.
                                                    Additional blower-
                                                    coil representations
                                                    are allowed for any
                                                    applicable
                                                    individual
                                                    combinations, if
                                                    distributed in
                                                    commerce.
                                Single-Split-      Every individual
                                 System AC with     combination
                                 Other Than         distributed in
                                 Single-Stage or    commerce, including
                                 Two-Stage          all coil-only and
                                 Compressor         blower coil
                                 (including Space-  combinations.
                                 Constrained and
                                 SDHV).

[[Page 16840]]

 
                                Single-Split-      Every individual
                                 System HP          combination
                                 (including Space-  distributed in
                                 Constrained and    commerce.
                                 SDHV).
                                Multi-Split,       For each model of
                                 Multi-Circuit,     outdoor unit, at a
                                 or Multi-Head      minimum, a non-
                                 Mini-Split Split   ducted ``tested
                                 System--non-SDHV   combination.'' For
                                 (including Space-  any model of outdoor
                                 Constrained).      unit also sold with
                                                    models of ducted
                                                    indoor units, a
                                                    ducted ``tested
                                                    combination.'' When
                                                    determining
                                                    represented values
                                                    on or after January
                                                    1, 2023, the ducted
                                                    ``tested
                                                    combination'' must
                                                    comprise the highest
                                                    static variety of
                                                    ducted indoor unit
                                                    distributed in
                                                    commerce (i.e.,
                                                    conventional, mid-
                                                    static, or low-
                                                    static). Additional
                                                    representations are
                                                    allowed, as
                                                    described in
                                                    paragraph (c)(3)(i)
                                                    of this section.
                                Multi-Split,       For each model of
                                 Multi-Circuit,     outdoor unit, an
                                 or Multi-Head      SDHV ``tested
                                 Mini-Split Split   combination.''
                                 System--SDHV.      Additional
                                                    representations are
                                                    allowed, as
                                                    described in
                                                    paragraph (c)(3)(ii)
                                                    of this section.
------------------------------------------------------------------------

    As presented in Table III-1, single-split CACs with single-stage or 
two-stage compressors are required to provide represented values for 
every individual combination distributed in commerce, each rated as a 
coil-only combination. For each model of outdoor unit, this must 
include at least one coil-only value that is representative of the 
least efficient combination distributed in commerce with that model of 
outdoor unit. Additional blower-coil ratings are allowed (i.e., 
optional) for any applicable individual combinations, if distributed in 
commerce. DOE has become aware that these provisions may contain 
ambiguity over the precise rating requirements for single-split CACs. 
For example, if the least efficient combination distributed in commerce 
for a given basic model includes a blower-coil indoor unit (as opposed 
to the assumption that a coil-only combination would be least 
efficient), the existing provisions are unclear on which combination 
would be used to rate the basic model. Accordingly, DOE is proposing to 
amend the language in the table found in 10 CFR 429.16(a)(1) to clarify 
the rating requirements pertaining to single-split CACs with single-
stage or two-stage compressors.\15\
---------------------------------------------------------------------------

    \15\ DOE's proposed clarifications would require every single-
stage and two-stage outdoor unit of single-split CAC to have a 
compliant rating with a coil-only combination that is distributed in 
commerce and representative of the least efficient combination 
distributed in commerce for that particular model of outdoor unit
---------------------------------------------------------------------------

    DOE requests comment on its proposal to clarify the language for 
required represented values of coil-only CACs found in the table at 10 
CFR 429.16(a)(1)
    The requirement to provide coil-only ratings for each basic model 
also applies to single split CACs designed for space-constrained 
applications (``SC-CAC''). DOE has received three petitions for test 
procedure waivers related to the represented value requirements for SC-
CACs. The first was a petition from National Comfort Products, Inc. 
(``NCP'') dated March 20, 2017 (Docket No. EERE-2017-BT-WAV-0030-0001); 
the second was a petition from AeroSys, Inc. (``AeroSys'') dated May 
29, 2017 (Docket No. EERE-2017-BT-WAV-0042-0001); and the third was a 
petition from First Company (``First Co.'') dated May 25, 2018 (Docket 
No. EERE-2018-BT-WAV-0012-0002). Each petitioner claimed that specified 
basic models of SC-CAC outdoor units listed in their respective 
petitions are designed and intended to be sold only with proprietary 
blower-coil indoor units equipped with high-efficiency electronically 
commutated (``ECM'') fan motors, and not as a coil-only combination 
(NCP, EERE-2017-BT-WAV-0030, No. 1 at p. 1; AeroSys, EERE-2017-BT-WAV-
0042; No. 1 at p. 1, First Co., EERE-2018-BT-WAV-0012, No. 2 at p. 1) 
Each petitioner also claimed that the identified blower-coil indoor 
units operate at a much lower wattage than the default fan power 
required by appendix M for coil-only combinations and asserted that 
appendix M would not result in a representative rating for the 
specified basic models (NCP, Id. at p. 2; AeroSys, Id. at p. 1, First 
Co., Id. at pp. 2-3) Each petitioner requested waivers requiring that 
the specified basic models be tested according to appendix M and that 
representations be determined by pairing models only with blower-coil 
indoor units (i.e., requesting exemption from the requirement in 10 CFR 
429.16(a)(1) to provide represented values based on a coil-only 
combination). (NCP, Id. at p. 3; AeroSys, Id. at p. 6, First Co., Id. 
at p. 6) These waiver requests were predicated on the premise that the 
basic models of outdoor units identified by NCP, AeroSys, and First Co. 
are not intended to be sold with a coil-only indoor unit pairing and 
are designed to be sold with only the specified blower-coil indoor 
units containing high-efficiency ECM fans.
    In a notice published May 30, 2021, DOE granted AeroSys's petition 
for interim waiver. Since that time, AeroSys filed for bankruptcy and 
thus DOE stopped further evaluation of the AeroSys test procedure 
waiver request.
    With respect to First Co.'s petition, DOE has concluded that 
statements provided in product specification sheets and installation 
instructions for the subject basic models appear inconsistent with 
First Co.'s assertion that the subject basic models are distributed in 
commerce exclusively for use with blower-coil indoor units. For 
example, installation instructions for affected models include language 
describing these units as replacements for R-22 systems, and the 
existing indoor units are unlikely to have the high-efficiency motors 
used in the described blower-coil indoor units. Additionally, some spec 
sheets include additional language indicating that installation is 
intended with existing indoor units that are unlikely to have high 
efficiency motors.
    As NCP's waiver petition and the prescribed alternate test 
procedure are specific to appendix M, the interim waiver will terminate 
on the date on which testing is required under appendix M1 (i.e., 
January 1, 2023); there is no need for continuation of the waiver once 
testing is required under appendix M1. Moreover, as discussed in the 
following paragraphs, DOE has tentatively determined that it would be 
inappropriate to amend appendix M1 to provide for the testing of split-
system

[[Page 16841]]

CACs as requested in the waiver petitions.
    DOE is required per EPCA to prescribe test procedures that are 
reasonably designed to produce test results which measure energy 
efficiency during a representative average use cycle or period of use, 
as determined by the Secretary. (42 U.S.C. 6293(b)(3)) For split-system 
central air conditioner and heat pump outdoor units, determination of 
what constitutes a representative average use cycle or period of use 
must include consideration of combinations in which a unit is paired in 
field installations. DOE published an energy conservation standard 
final rule to set new standards for central air conditioners and heat 
pumps on January 6, 2017. 82 FR 1786. In the rulemaking that culminated 
in this final rule, DOE examined the typical installations for split-
system CACs and HPs as part of its assessment of life-cycle costs. DOE 
determined that 39 percent of split-system CAC installations in 2021 
\16\ would be full-system replacements including a blower-coil indoor 
unit. Of the 61 percent remaining CAC installations, DOE's determined 
that 75 percent of these would require replacement of the entire system 
(i.e., both outdoor unit and coil-only indoor unit) and 25 percent 
would involve solely replacement of the outdoor unit (i.e., leaving the 
existing coil-only indoor unit and refrigerant line-sets intact). 
(Docket No. EERE-2014-BT-STD-0048-0098, p. 8-8).
---------------------------------------------------------------------------

    \16\ DOE based its life-cycle analysis on the assumption that 
the year of product purchase date would be 2021, which at the time 
was the assumed effective date of energy conservation standards for 
CACs and HPs. Accordingly, all installation figures were forecast 
through the year 2021.
---------------------------------------------------------------------------

    DOE's analysis indicates that installations involving blower-coil 
indoor units are in the minority for split-system CACs. While DOE does 
not have data showing the installation breakdown specifically for 
space-constrained systems, DOE assumes in the absence of such data that 
the general installation trends would apply to equally to space-
constrained systems. Additionally, DOE has observed instances for which 
outdoor units designed for space-constrained applications are being 
distributed in commerce without a corresponding blower-coil indoor 
unit,\17\ indicating the potential for pairing a replacement outdoor 
unit with an existing indoor unit using a legacy fan that would not 
likely be comparable to the ECM fan of the blower-coil indoor unit on 
which the system rating is based. DOE notes that the cited example is 
for sale of an NCP outdoor unit, which indicates that it is impossible 
to ensure that installations are of systems with blower-coil indoor 
units, as suggested by NCP's waiver petition.
---------------------------------------------------------------------------

    \17\ www.ferguson.com/product/national-comfort-products-3000-series-25-tons-12-seer-r-410a-27200-btuh-room-air-conditioner-nncpe4303010/_/R-4397660.
---------------------------------------------------------------------------

    Consequently, DOE tentatively concludes that measuring the 
performance of space-constrained systems exclusively with high-
efficiency blower-coil combinations, as requested in the NCP, AeroSys, 
and First Co. waiver petitions, is not generally representative of 
field operation. Based on this tentative conclusion, amendment to the 
existing requirements for represented values in 10 CFR 429.16 to allow 
manufacturers to avoid the coil-only test requirement for single-speed 
and two-stage space-constrained CACs would provide test results that 
are not representative of an average use cycle or period of use. DOE is 
not proposing amendments to appendix M1 regarding the test procedure 
waiver granted to NCP.
    DOE requests comment on its planned approach not to propose waiving 
the coil-only rating requirement for space-constrained air conditioners 
and heat pumps. To support any comments suggesting that DOE reverse 
this decision, DOE requests shipment and/or installation data for 
space-constrained systems to clarify the characteristics of 
representative installations.

C. Other Test Procedure Revisions

1. Air Volume Rate Changing With Outdoor Conditions
    When testing CAC/HP systems under appendix M1, section 3.1.4 
requires determining airflow setting(s) before testing begins; unless 
otherwise specified, no changes are to be made to the airflow 
setting(s) after initiation of testing. The subsections of section 
3.1.4 provide instructions for establishing air volume rates for the 
following test conditions: Cooling full-load (section 3.1.4.1), cooling 
minimum (section 3.1.4.2), cooling intermediate (section 3.1.4.3), 
heating full-load (section 3.1.4.4), heating minimum (section 3.1.4.5), 
heating intermediate (section 3.1.4.6), and heating nominal (section 
3.1.4.7).
    For example, section 3.1.4.1.1.a of appendix M1 provides 
instructions for determining the cooling full-load air volume rate for 
ducted blower coil systems other than those having a constant-air-
volume-rate indoor blower. Within that section, a seven-step process is 
followed to determine the final fan speed or control settings to be 
used for testing. Step (7) of the process specifies using the measured 
air volume rate as the cooling full-load air volume rate, and to use 
the final fan speed or control settings for all tests that use the 
cooling full-load air volume rate. Sections 3.1.4.2.a and 3.1.4.4.3.a 
specify a similar process for determining cooling minimum air volume 
rate and heating full-load air volume rate, respectively. These 
sections similarly specify using use the measured air volume rate and 
final fan speed or control settings for all tests that use the cooling 
minimum air volume rate or heating full-load air volume rate, 
respectively.
    As noted, sections 3.1.4.1.1.a, 3.1.4.2.a, and 3.1.4.3.a of 
appendix M1 specify using the air volume rates determined in those 
respective sections for all tests. By contrast, sections 3.2.2.2, 
3.2.3.b, and 3.2.4.b specify using air volume rates that represent a 
``normal installation'' when testing units having a single-speed 
compressor where the indoor section uses a single variable-speed 
variable-air-volume rate indoor blower or multiple indoor blowers 
(3.2.2.2), when testing units having a two-capacity compressor 
(3.2.3.b), and when testing units having a variable-speed compressor 
(3.2.4.b). In some cases, reference to ``air volume rates that 
represent a normal installation'' could conflict with the air volume 
rates determined in sections 3.1.4.1.1.a, 3.1.4.2.a, and 3.1.4.3.a.
    For example, many modern blower-coil systems have multiple-speed or 
variable-speed indoor fans and control systems (i.e. the type of units 
covered under section 3.2.2.2) that may have the capability to vary fan 
speed in response to operating conditions in order to optimize 
performance. Under ``normal installation'' for such units, air volume 
rate changes in response to operating conditions such as outdoor air 
temperature. For these types of systems, the instructions in sections 
3.1.4.1.1.a, 3.1.4.2.a, and 3.1.4.3.a to use a fixed (constant) air 
volume rate for all tests conflict with the instructions in sections 
3.2.2.2, 3.2.3.b, and 3.2.4.b to use air volume rates that represent a 
normal installation.
    For units with multiple-speed or variable-speed indoor fans and 
control systems that have the capability to vary fan speed in response 
to operating conditions, requiring air volume rate to remain constant 
as outdoor air temperature changes during testing may not provide test 
results that are representative of field operation.
    To address this issue, DOE proposes to explicitly state in Step 7 
of sections 3.1.4.1.1.a, 3.1.4.2.a, and 3.1.4.3.a that,

[[Page 16842]]

for blower coil systems in which the indoor blower capacity modulation 
correlates with outdoor dry bulb temperature or sensible to total 
cooling capacity ratio, use an air volume rate that represents a normal 
operation. To ensure consistency of testing, it may be necessary for 
manufacturers to certify whether the system varies blower speeds with 
outdoor air conditions. However, this change is not being proposed in 
this notice and may be addressed in a separate rulemaking.
    DOE requests comments on its proposal to add language clarifying 
how to implement variation of blower speed for different ambient 
temperature test conditions.
2. Wet Bulb Temperature for H4 5 [deg]F Heating Tests
    Appendix M1 specifies required and optional heating mode test 
conditions for heat pumps, designated as ``H'' conditions. See Tables 
11 through 15 of appendix M1. appendix M1 provides for conducting 
optional ``H4'' heating tests at a 5 [deg]F outdoor ambient dry-bulb 
temperature and, at a maximum, a 3 [deg]F outdoor wet-bulb 
temperature.\18\ DOE initially proposed a target wet-bulb temperature 
for the H4 test of 3.5 [deg]F in an SNOPR published in August 2016 
(``August 2016 SNOPR''). 81 FR 58164, 58193. ACEEE, NRDC, and ASAP 
agreed with DOE's proposal of a target wet bulb temperature of 3.5 
[deg]F for the optional 5 [deg]F test. (ACEEE, NRDC, and ASAP, EERE-
2016-BT-TP-0029, No. 33 at p. 8) Carrier/UTC, Lennox, JCI, Ingersoll 
Rand, Goodman, Nortek, NEEA, Rheem, the CA IOUs, AHRI, and Mitsubishi 
all recommended that the target wet bulb temperature for the 5 [deg]F 
test should be 3 [deg]F or less, rather than the proposed 3.5 [deg]F 
target. The commenters indicated that holding tight tolerances on the 
wet bulb temperature at such low temperatures is very challenging, but 
the frost loading for this temperature is so low that the variation in 
the wet bulb temperature level would not affect the test significantly. 
Unico made a similar recommendation but suggested a maximum of 4 [deg]F 
wet bulb temperature. (Carrier/UTC, No. 36 at p. 12; Lennox, EERE-2016-
BT-TP-0029, No. 25 at p. 15; JCI, EERE-2016-BT-TP-0029, No. 24 at p. 
17; Ingersoll Rand, EERE-2016-BT-TP-0029, No. 38 at p. 7, Goodman No. 
39 at p. 11; Nortek, EERE-2016-BT-TP-0029, No. 22 at p. 16; Unico, 
EERE-2016-BT-TP-0029, No. 30 at p. 7; NEEA, EERE-2016-BT-TP-0029, No. 
35 at p. 3; Rheem, EERE-2016-BT-TP-0029, No. 37 at p. 6; CA IOU, EERE-
2016-BT-TP-0029, No.32 at p.4; AHRI, EERE-2016-BT-TP-0029, No. 27 at 
p.19; Mitsubishi, No. 29 at p.4).
---------------------------------------------------------------------------

    \18\ The tests at this condition are optional for heat pumps, 
except for Triple-Capacity Northern heat pumps.
---------------------------------------------------------------------------

    In the January 2017 TP Final Rule, DOE agreed that the amount of 
moisture in 5 [deg]F air would be sufficiently low that imposing a 
maximum wet bulb temperature of 3 [deg]F would be adequate to ensure 
test repeatability; hence DOE adopted the suggestion to require a 3 
[deg]F maximum wet bulb temperature in the January 2017 TP Final Rule 
(82 FR 1426). Since the publication of the 2017 Final Rule, DOE and 
other stakeholders have gained additional experience testing to the new 
appendix M1, including testing at the 5 [deg]F H4 heating condition. 
DOE has received informal comments and has independently observed that 
holding the wet-bulb tolerance of maximum 3 [deg]F is difficult for 
some test labs, especially for extended periods of time, and that even 
if this low humidity level can be attained, the additional 0.5 to 1.0 
[deg]F wet bulb reduction adds significant time to testing (as compared 
to maximum wet bulb requirements of 3.5 [deg]F and 4 [deg]F, 
respectively).
    The 3 [deg]F wet bulb condition represents an extremely dry air 
condition, which is difficult to attain and maintain due to issues with 
infiltration and ground moisture passing through the floor in some 
laboratory setups. Accordingly, DOE is proposing to amend the wet bulb 
test condition for all H4 tests to be 4 [deg]F maximum instead of the 
current condition of 3 [deg]F maximum. Because, as previously 
identified in comments, there is very little moisture content in the 
air at 5 [deg]F dry-bulb temperature, DOE does not expect that the 
change in wet bulb temperature condition will have a significant impact 
on test results.
    DOE seeks comment on its proposal to amend the wet bulb temperature 
condition for the H4 heating tests from the existing 3 [deg]F maximum 
temperature to a maximum temperature of 4 [deg]F.
3. Hierarchy of Manufacturer Installation Instructions
    Instructions for installation of CAC/HP products can take multiple 
forms, including documents shipped with the product, labels affixed to 
the outdoor unit and/or indoor unit, and online documents.
    Section 2(A) of appendix M1 provides requirements regarding the 
installation instructions to be used and their order of precedence 
(i.e., installation instruction hierarchy) for variable refrigerant 
flow (``VRF'') multi-split systems. Section 2(A) specifies that 
installation instructions that appear in the labels applied to the unit 
take precedence over installation instructions that are shipped with 
the unit. Further, Section 2(A) specifies that the term 
``manufacturer's installation instructions'' does not include online 
manuals. Appendix M1 does not specify installation instruction 
hierarchy for any other types of CAC/HP products.
    Throughout appendix M1, references to manufacturer's installation 
instructions are made regarding refrigerant charging requirements 
(section 2.2.5), installation of an air supply plenum adapter accessory 
for testing small-duct, high-velocity systems (section 2.4.1.c), and 
control circuit connections between the furnace and the outdoor unit 
for coil-only systems (section 3.13.1.a).
    DOE notes that it initially proposed in a supplemental NOPR 
published November 9, 2015 (``November 2015 SNOPR'') that the hierarchy 
of installation instructions be located in proposed section 2.2.5.1 of 
appendix M1, which pertains to refrigerant charging requirements. See 
80 FR 69278, 69350.\19\ However, as finalized in the June 2016 Final 
Rule, the installation instruction hierarchy provision was located 
within section 2(A) of appendix M1, and therefore applies only to 
testing of VRF multi-split systems. 81 FR 36992, 37060. The June 2016 
Final Rule did not provide a discussion of this change.
---------------------------------------------------------------------------

    \19\ DOE also notes that as initially proposed, installation 
instructions that are shipped with the unit were to take precedence 
over installation instructions that appear in the labels applied to 
the unit, but this hierarchy was reversed in the final rule. 81 FR 
36992, 37060.
---------------------------------------------------------------------------

    The requirements regarding installation instruction would be 
equally applicable to classes of CAC/HP other than VRF multi-split 
systems. As noted, manufacturer's installation instructions are 
referenced in a number of provisions in appendix M1. Therefore, DOE is 
proposing to add in section 2(B) of appendix M1, ``Testing Overview and 
Conditions for Systems Other than VRF,'' the same requirements 
associated with installation instructions that are in section 2(A), 
i.e. what instructions can be used and what instructions take 
precedence. This proposal would align the approach for all classes of 
CAC/HP with the current approach for VRF CAC.
    DOE requests comment on the proposed alignment of the VRF and non-
VRF test procedures when it comes to instruction precedence.

[[Page 16843]]

4. Adjusting Airflow Measurement Apparatus To Achieve Desired SCFM at 
Part-Load Conditions
    DOE is aware that the specifications for cooling full-load air 
volume rates for both ducted and non-ducted units may require 
additional detail to provide improved repeatability. Sections 
3.1.4.1.1, 3.1.4.2, and 3.1.4.4.3 of appendix M1 each specify seven 
steps for achieving the correct air volume rate to be used for testing 
(cooling full-load air volume rate, cooling minimum air volume rate, 
and heating full-load air volume rate, respectively). In each section, 
Step 7 mentions ``fan speed'' and ``control settings'' without 
indicating whether they are the speed and settings of the unit under 
test, of the airflow measurement apparatus, or both. DOE notes that 
cooling full-load air volume rate, cooling minimum air volume rate, and 
heating full-load air volume rate may each be used for multiple test 
conditions. However, when using this same air-volume rate at different 
test conditions, it may be necessary to adjust one of the fans to 
achieve the same air-volume rate, due to differences in air density 
and/or loading of condensate on the indoor coil.\20\ In sections 
3.1.4.1.1, 3.1.4.2, and 3.1.4.4.3 of appendix M1, Step 7 identifies the 
air volume rate (cooling full-load, cooling minimum, and heating full-
load, respectively) to be used for all test conditions that use the 
same air volume rate, but it does not indicate what adjustments are 
allowed or required to obtain it.
---------------------------------------------------------------------------

    \20\ When operating in cooling mode, water vapor in the return 
air may condense and collect and flow down the coil into the indoor 
unit's drain pan. This removal of water vapor is called 
dehumidification--it occurs only in cooling mode and its magnitude 
depends on the test conditions.
---------------------------------------------------------------------------

    These sections may be misinterpreted to indicate that both the fan 
speed of the unit under test and the airflow measurement apparatus fan 
speed should not be adjusted during testing. As previously described, 
if both the test unit fan speed and the measurement apparatus fan speed 
are fixed, differences in air density and/or loading of condensate 
could cause differences in measured air volume rate at different test 
conditions, with no recourse for correction. This interpretation could 
then cause tests to be conducted at different air volume rates across 
test conditions, whereas the test procedure at sections 3.1.4.1.1, 
3.1.4.2, and 3.1.4.4.3 of appendix M1 requires the tests to be 
conducted at the same air volume rate across different conditions. To 
minimize the potential for misinterpretation, DOE is proposing to 
explicitly require that the airflow measurement apparatus fan be 
adjusted if needed to maintain constant air volume rate for all tests 
using the same air volume rate. Similarly, the section would explicitly 
state that the speed and settings of the fan of the unit under test are 
not to be adjusted.
    DOE requests comment on its proposal to add more specific direction 
to step 7 of sections 3.1.4.1.1, 3.1.4.2, and 3.1.4.4.3.
5. Revision of Equations Representing Full-Speed Variable-Speed Heat 
Pump Operation at and Above 45 [deg]F Ambient Temperature
    A compressor's speed at full speed may change as the outdoor 
temperature changes. While the compressor speed at full speed may 
differ at different outdoor temperatures, accuracy of predictions using 
the test results from two temperature conditions to calculate the 
performance for a third temperature condition is maximized when the 
same compressor speed is used for the tests at the two different 
ambient temperature conditions (see, e.g., 81 FR 58164, 58178 (August 
24, 2016)).
    For calculation of full-compressor performance in the temperature 
ranges less than 17 [deg]F and greater than or equal to 45 [deg]F, the 
test procedure determines performance based on the H32 and 
H12 tests, which are conducted at 17 [deg]F and 47 [deg]F, 
respectively (see appendix M1, sections 4.2.4.c, which refers to 
equations 4.2.2-3 and 4.2.2-4 in Section 4.2.2). As indicated in 
appendix M1 in the Table 14 footnotes, the H12 test is run 
with the compressor speed that represents normal operation at 17 [deg]F 
conditions. However, for many variable-speed heat pumps, this is a 
higher compressor speed than would be normal for operation at 47 [deg]F 
conditions.
    The H1N test represents normal 47 [deg]F operation, as 
indicated in the Table 14 footnotes. For heat pumps with different 
normal speeds for 17 [deg]F and 47 [deg]F conditions, the full-
compressor performance equation is not appropriately representative for 
temperatures greater than or equal to 45 [deg]F. For example, at 47 
[deg]F, the equation would indicate that the capacity is equal to the 
H12 capacity, even though the H1N test is 
specifically intended to represent capacity at 47 [deg]F. To rectify 
this issue, DOE proposes to amend the portion of the equations 
representing performance in conditions warmer than 45 [deg]F. 
Specifically, the capacity equation for this temperature range would be 
multiplied by the ratio of the capacities of the H1N and 
H12 tests. Similarly, the power input equation for this 
range would be multiplied by the ratio of the power inputs measured in 
the H1N and H12 tests. This would change the 
calculated capacity and power input for the range of temperature above 
45 [deg]F to be consistent with the compressor speed of the 
H1N test (which is intended to represent performance in this 
range), rather than with the compressor speed of the H32 
test, which is conducted in a 17 [deg]F ambient temperature.
    While DOE believes that the proposed amendments would provide more 
representative results, DOE does not expect that such changes would 
significantly affect heat pump HSPF2 measurements. This is because the 
full-capacity performance would affect HSPF2 only when the calculated 
building load exceeds the calculated intermediate capacity of a 
variable-speed heat pump, which DOE believes to be a rare occurrence in 
the ambient temperature range above 45 [deg]F. In the cases that would 
affect HSPF2, the change would increase the measured efficiency, since 
H1N COP is expected to be higher than H12 COP due 
to its lower compressor speed.
    DOE requests comment on the proposed change to the full-capacity 
performance equations for variable-speed heat pumps in the ambient 
temperature range above 45 [deg]F, adjusting the equations for capacity 
and power by the ratio of capacity and power, respectively, associated 
with H1N and H12 operation.
6. Calculations for Triple-Capacity Northern Heat Pumps
    Section 4.2.6 of appendix M1 includes additional steps for 
calculating HSPF2 of a heat pump having a triple-capacity compressor. 
Heat pumps with triple-capacity compressors respond to building heating 
load by operating at low (k=1), high (k=2), or booster (k=3) capacity 
or by cycling on and off at one or more of those stages. Section 
4.2.6.5 covers the scenario where the heat pump alternates between high 
(k=2) and booster (k=3) compressor capacity to satisfy the building 
load. In this scenario, the total electrical power consumption is 
determined by calculating the fraction of time the system spends 
operating in the high and booster stage, respectively, and then 
weighting the steady-state power consumption at each operating state 
accordingly. Section 4.2.6.5 gives equations for calculating the 
fraction of load addressed by the high compressor stage, denoted as 
``Xk=2(Tj)'', as well as the fraction of load 
addressed by the booster compressor stage 
``Xk=3(Tj)''. These proportions should, by 
definition, be complementary because the system is

[[Page 16844]]

either operating in high compressor stage or boost compressor stage. 
However, the equation for the booster capacity load factor 
``Xk=3(Tj)'' is erroneously set equal to the 
high-capacity load factor ``Xk=2(Tj)'' as opposed 
to the complementary value ``1 Xk=2(Tj).'' 
Therefore, DOE is proposing to correct the booster capacity load factor 
equation to be defined as Xk=3(Tj) = 1 - 
Xk=2(Tj).
    DOE seeks comment on its proposal to revise the calculation for 
booster capacity load factor equation for triple-capacity northern heat 
pumps.
7. Heating Nominal Air Volume Rate for Variable-Speed Heat Pumps
    Appendix M1 includes procedures for calculating the heating 
capacity and power input for variable-speed heat pumps at various test 
conditions. The H1N test is used to calculate the nominal 
heating capacity of the system at 47 [deg]F ambient temperature, 
whereas the H12 test is used to calculate maximum heating 
capacity at 47 [deg]F and the H11 test is used to calculate 
minimum heating capacity at 47 [deg]F. Section 3.1.4.7 of appendix M1 
requires that manufacturers must specify a heating nominal air volume 
rate for each variable-speed heat pump system and must provide 
instructions for setting the fan speed or controls. The heating full-
load air volume rate is defined in section 3.1.4.4 of appendix M1, 
which ties the heating full-load air volume rate to the cooling full-
load air volume rate and denotes static pressure requirements. However, 
in Table 14 to appendix M1 (which specifies heating mode test 
conditions for units having a variable-speed compressor), the 
H1N test (used for calculating nominal heating capacity at 
47 [deg]F) is erroneously specified as using the ``Heating Full-load'' 
air volume rate instead of the heating nominal air volume rate. Because 
the H1N test is intended to represent nominal heating 
capacity, DOE is proposing to amend Table 14 to specify the ``heating 
nominal air volume rate'' as defined in section 3.1.4.7 of appendix M1 
as opposed to the ``heating full-load air volume rate''. As discussed 
in section I.B.2 of this NOPR, DOE is also proposing to amend the test 
provisions for variable-speed compressor systems with coil-only indoor 
units. The proposal mentioned in this section would only apply to 
variable-speed systems equipped with blower-coil indoor units, while 
variable-speed coil-only systems would be required to test using the 
heating full-load air volume rate at the H1N test condition.
    DOE requests comment on its proposal to specify heating nominal air 
volume rate as the air volume rate to be used for the H1N 
heating test for variable-speed heat pumps.
8. Clarifications for HSPF2 Calculation
    Section 4.2 of appendix M1 contains methodologies for calculating 
HSPF2 for all heat pumps. DOE has identified an instance where 
additional instruction may be warranted to make clear the calculation 
procedure across different types of heat pump systems. DOE proposes to 
clarify the appropriate slope adjustment factor to be used in the 
calculation for building heating load (Equation 4.2-2).
    As written, Equation 4.2-2 refers to the heating load line slope 
adjustment factor ``C'', which varies by climate region according to 
Table 20. However, Table 20 includes both the ``C'' factor as well as a 
factor denoted ``CVS''--the variable-speed slope factor, 
which includes different coefficients that impact calculation of HSPF2. 
CVS is not explicitly referenced in the definitions 
surrounding Equation 4.2-2, therefor DOE is proposing to amend the 
language of that paragraph to indicate that the slope adjustment factor 
``C'' should be used when calculating building heating load except for 
variable-speed compressor systems, where the variable-speed slope 
adjustment factor ``CVS'' should be used instead.
    DOE seeks comment on its proposal to clarify the calculation 
process for heating load line slope factor as it pertains to variable-
speed heat pumps.
9. Distinguishing Central Air Conditioners and Heat Pumps From 
Commercial Equipment
    EPCA defines ``industrial equipment'' as equipment of a type which, 
among other requirements, is not a covered product under section 
6291(a)(2), i.e., not a covered consumer product. (42 U.S.C.6311(2)(A)) 
Small, large, and very large commercial package air conditioning and 
heating equipment are included as types of covered industrial 
equipment. (42 U.S.C.6311(1)(B,C,D))
    EPCA defines ``central air conditioner'' as a product, other than a 
packaged terminal air conditioner, which is powered by single phase 
electric current, is air-cooled, is rated below 65,000 Btu per hour, is 
not contained within the same cabinet as a furnace the rated capacity 
of which is above 225,000 Btu per hour, and is a heat pump or a cooling 
only unit. DOE understands that there are basic models that exists on 
the market that meet the central air conditioner definition but are 
exclusively distributed in commerce for commercial and industrial 
applications. In DOE's view, there are certain types of equipment that 
meet the definition of CAC but that EPCA was not intended to regulate 
as consumer products. To clarify that any such model is not a central 
air conditioner, DOE proposes to revise the central air conditioner 
definition so that it explicitly excludes these equipment categories, 
similar to the way the definition excludes packaged terminal air 
conditioners and packaged terminal heat pumps. The exclusion for 
single-package vertical air-conditioners and heat pumps would refer 
specifically to those models that could be confused with central air 
conditioners, i.e., those that are single-phase with capacity less than 
65,000 Btu/h, for which the test procedure notice of proposed 
rulemaking for single-package vertical air conditioners and heat pumps 
has proposed new definitions. 87 FR 2490, 2518 (January 14, 2022).
    DOE emphasizes that the exclusion from the central air conditioner 
definition for a given model depends on whether it meets the definition 
for one of the excluded categories. For example, a model must meet the 
packaged terminal air conditioner definition to be considered to be a 
packaged terminal air conditioner. Suppose a model meets the 
characteristics listed in the central air conditioner definition, but 
otherwise has similarities to packaged terminal air conditioners. If 
such a model is not ``intended for mounting through the wall,'' it 
would be missing a key characteristic of the packaged terminal air 
conditioner definition (see 10 CFR 431.92), and, unless it met the 
definition for one of the other categories proposed to be excluded, it 
is considered a central air conditioner irrespective of whether it gets 
installed in a consumer or commercial building.
10. Additional Test Procedure Revisions
    On May 8, 2019, AHRI submitted a comment responding to the notice 
of proposal to revise and adopt procedures, interpretations, and 
policies for consideration of new or revised energy conservation 
standards (2020 Process Rule NOPR, 84 FR 3910, Feb. 13, 2019). The 
comment included as Exhibit 2 a ``List of Errors Found in appendix M 
and appendix M1'' (``AHRI Exhibit 2'', EERE-2017-BT-STD-0062-0117 at 
pp. 23-24). Many of the errors pointed out by AHRI regard typographical 
errors in appendix M and appendix M1. DOE published a notice of 
corrections to appendices M and M1 on December 2, 2021 (``December 2021 
Corrections Notice''). 86 FR 68389. The December 2021 Corrections 
Notice

[[Page 16845]]

addressed some of the ``Errors'' identified in AHRI Exhibit 2, but not 
all of them. DOE is proposing to address additional ``Errors'' 
identified in AHRI Exhibit 2 in this NOPR to improve accuracy and 
representativeness of the test procedures.
a. Revisions Specific to Appendix M
    AHRI's comment identified three areas of appendix M where they 
requested changes. These are detailed in Table III-2. Additionally, DOE 
has identified one transcription error in the December 2021 Corrections 
Notice related to changes made in section 3.6.4 of appendix M. DOE is 
making corresponding revisions in this NOPR to correct that 
transcription error.

                                Table III-2--AHRI-Identified Errors to Appendix M
----------------------------------------------------------------------------------------------------------------
                                 Original appendix M
          Section                      language              AHRI comment summary           Proposed change
----------------------------------------------------------------------------------------------------------------
1.2........................  ``Nominal cooling capacity   The H1N test is required    Remove the ``Optional H1N
                              is approximate to the air    in section 3.6.4, and       test'' and replace the
                              conditioner cooling          section 3.6.4 designates    ``H12'' with ``H1N''.
                              capacity tested at A or A2   the H1N test--not the H12
                              condition. Nominal heating   test.
                              capacity is approximate to
                              the heat pump heating
                              capacity tested in H12
                              test (or the optional H1N
                              test)''.
4.1.4.2....................  ...........................  The EER\k=1\(Tj) should be  Revise the formula to
                                                           EER\k=2\(Tj) because the    implement this change to
                                                           coefficient ``A'' only      EER\k=2\(Tj).
                                                           utilizes the maximum
                                                           speed temperature, T2.
4.2.c......................  ``For a variable-speed heat  2017 and later versions of  Accurately implement the
                              pump, Qh\k\(47) =            appendix M use H\k=2\calc   change intended by the
                              Qh\k=N\(47), the space       for all conditions, as      December 2021 Corrections
                              heating capacity             explained in 3.6.4. This    Notice.
                              determined from the H1N      should not be an
                              test''.                      exception for the rest of
                                                           the calculations.
----------------------------------------------------------------------------------------------------------------

    The following sections discuss proposed changes to the language of 
appendix M that DOE believes will improve clarity regarding how tests 
and calculations are to be conducted to determine capacity levels and 
efficiency metrics.
i. Definition of Nominal Cooling Capacity
    AHRI commented that the definition of Nominal Cooling Capacity in 
Section 1.2 of appendix M incorrectly references the H1N 
test as ``optional.'' AHRI claimed that, on the contrary, the 
H1N test is required for heat pumps. DOE agrees with the 
AHRI comment, since Section 3.6.4, ``Tests for a Heat Pump Having a 
Variable-Speed Compressor,'' requires the H1N test. 
Therefore, DOE is proposing to revise the definition of ``Nominal 
Capacity'' to remove the references to the H12 test in its 
entirety. Referring to the H1N test will avoid confusion.
ii. Revising Energy Efficiency Ratio Equation at Intermediate 
Compressor Speed
    In section 4.1.4.2 of appendix M, there are a series of equations 
used to calculate EER\k=i\(Tj), the steady-state energy 
efficiency ratio of the test unit when operating at an intermediate 
compressor speed (k=i) for outdoor temperature Tj. This 
value is calculated using a quadratic equation: EER\k=i\(Tj) 
= A + B*Tj + C*Tj\2\. These coefficients (A, B 
and C) are calculated by their own respective formulae.
    AHRI commented that the formula for the ``A'' coefficient has an 
error. Specifically, EER\k=1\(T2) in the equation should be 
EER\k=2\(T2) because the coefficient ``A'' only utilizes 
maximum-speed temperature T2. As described further in this 
section, DOE is proposing to revise this calculation such that it uses 
the intended ``k=2''. The use of ``k=2'' is supported both by its 
appearance in ASHRAE 116-2010, ``Methods for Testing for Rating 
Seasonal Efficiency of Unitary Air Conditioners and Heat Pumps'' (see 
page 25) and also in the DOE test procedure final rule that first 
established test methods for variable-speed systems. 49 FR 8304, 8316 
(March 14, 1987).
iii. Clarification of Compressor Speed Limits in Heating Tests for Heat 
Pumps Having a Variable-Speed Compressor
    In the December 2021 Corrections Notice, DOE discussed corrections 
to the compressor speed limitations for the H1N heating mode 
test for both appendix M and appendix M1. 86 FR 68389, 68390. However, 
when setting out the correcting language in the amendatory instruction 
for appendix M, the instructions erroneously directed to revise the 
fifth sentence of paragraph a to section 3.6.4, when the instructions 
were intended to revise the seventh sentence of the same paragraph. As 
currently printed, the text in paragraph a of section 3.6.4 to appendix 
M includes two sentences starting with ``for a cooling/heating heat 
pump . . .'' that give conflicting instructions. Accordingly, DOE is 
proposing to revise this paragraph to reflect the intent of the 
December 2021 Corrections Notice and, by extension, the January 2017 
Final Rule.
b. Revisions Specific to Appendix M1
    AHRI's comment identified one area of appendix M1 where they 
requested changes. This requested change is detailed in Table III-2.

[[Page 16846]]



           Table III-3--AHRI-Identified Errors to Appendix M1
------------------------------------------------------------------------
                           Original
       Section           appendix M1      AHRI comment   Proposed change
                           language         summary
------------------------------------------------------------------------
4.2..................  Qh(47 [deg]F):   For variable     Revise the
                        the heating      speed heat       language to be
                        capacity at 47   pumps, the       clearer about
                        [deg]F           language         what capacity
                        determined       should be        to use for
                        from the H2      clarified to     different
                        H12 or H1N       H\k=2\ calc..    types of
                        test, Btu/h..                     heating-only
                                                          heat pumps.
------------------------------------------------------------------------

    The following sections discuss proposed changes to the language of 
appendix M1 that DOE believes will improve clarity regarding how tests 
and calculations are to be conducted to determine capacity levels and 
efficiency metrics.
i. Detailed Descriptions of Capacity for Different Subcategories
    AHRI commented that in Section 4.2 of appendix M1, which describes 
the calculation for HSPF2 for different subcategories of heat pumps, 
there is a lack of clarity in the term for heating capacity measured at 
47 [deg]F, ``Qh(47 [deg]F),'' in Equation 2-2, the building 
load, ``BL(Tj),'' equation. Currently, the description of 
Qh(47 [deg]F) says that it is ``determined from the H, 
H12 or H1N test.'' Additionally, the first ``H'' 
is missing an additional character to specify the appropriate test 
point. DOE agrees with AHRI's assessment of this description, and DOE 
is proposing to revise this description to include specific 
instructions for which test point is appropriate for different heat 
pump subcategories. DOE is proposing to specify that the H1 test is for 
a heat pump with a single-speed compressor, the H12 test is 
for a heat pump with a two-speed compressor, and the H1N 
test is for a heat pump with a variable-speed compressor.
    However, AHRI commented regarding a ``H\k=2\calc'' term. 
DOE notes that this term does not exist in this section of appendix M1. 
While DOE is revising this section to add clarity in light of AHRI's 
general comment, DOE will not be proposing to make the exact edit AHRI 
proposes.
c. Revisions to Both Appendix M and Appendix M1
    AHRI's comment claimed that there are two sections in both appendix 
M and appendix M1 that contain similar errors. These errors are 
detailed below in Table III-4.
[GRAPHIC] [TIFF OMITTED] TP24MR22.000

    The following sections discuss proposed changes to the language of 
both appendix M and appendix M1 that DOE believes will improve clarity 
regarding how tests and calculations are to be conducted to determine 
capacity levels and efficiency metrics.
i. Revising Part Load Factor Equation for Heat Pumps in Section 4.2.3.3
    AHRI's comment claims that the part load factor (PLF) equation in 
section 4.2.3.3 of both appendix M and appendix M1 contain two errors. 
The first error is that the equation is missing a closing square 
bracket, and the second is that the heating mode low-capacity load 
factor, ``X\k=1\(Tj),'' is incorrectly referenced instead of 
the high-capacity load factor, ``X\k=2\(Tj).'' DOE notes 
that this equation is actually correct in appendix M1. The high-
capacity load factor is appropriate in this equation because section 
4.2.3.3 applies to heat pumps that only operate at high (k=2) 
compressor capacity. Therefore, the high-capacity load factor should be 
used in this case for the part load factor. DOE is proposing to revise 
this formula in appendix M to include the closing square bracket and to 
use the high-capacity load factor.
ii. Revising the Ratio of Electrical Energy Used for Resistive Space 
Heating Equation in Section 4.2.3.4
    AHRI has identified an error in the equation for electrical energy 
consumed by the heat pump for electric resistance auxiliary heating for 
bin temperature, Tj divided by the total number of hours in 
the heating season, ``RH(Tj)/N,'' used in section 4.2.3.4 of 
both appendix M and appendix M1. AHRI indicated that the equation used 
in section 4.2.3.4

[[Page 16847]]

includes a multiplication operator where it should have subtraction. 
The subtraction operator is consistent with all other instances of 
RH(Tj)/N in both appendix M and appendix M1. DOE agrees that 
the equation for RH(Tj)/N in section 4.2.3.4 of both 
appendix M and appendix M1 is incorrect, and therefore DOE is proposing 
to revise this equation to include the subtraction operator rather than 
a multiplication operator.
    DOE requests comments on the proposals to implement the correcting 
revisions described in this section.

D. Other Representation Proposed Revisions

    Manufacturers, including importers, must use product-specific 
certification templates to certify compliance to DOE. For CAC/HPs, the 
certification template reflects the general certification requirements 
specified at 10 CFR 429.12 and the product-specific requirements 
specified at 10 CFR 429.16. As discussed in the previous paragraphs, 
DOE is not making any proposals related to certification requirements 
in this rulemaking and any such changes may be addressed in a future 
rulemaking.
1. Required Represented Values for Models Certified Compliant With 
Regional Standards
    DOE's standards for CAC at 10 CFR 430.32(c) include both amended 
national standards with which compliance is required for models 
manufactured on or after January 1, 2023, and amended regional 
standards with which compliance is required for units installed on or 
after January 1, 2023. See 10 CFR 430.32(c)(5)-(6). In addition, as 
discussed in section III.B.3, DOE's regulations at 10 CFR 429.16 
describe certification requirements for central air conditioners and 
central air conditioning heat pumps, and paragraph (a)(1) of this 
section requires single-split CACs with single-stage or two-stage 
compressors, at a minimum, to rate each outdoor model as part of a 
coil-only combination representative of the least efficient combination 
distributed in commerce with that particular outdoor unit.
    On December 16, 2021, DOE issued final guidance regarding whether a 
model of outdoor unit for a single-split-system AC with single-stage or 
two-stage compressor whose coil-only rating under M1 does not meet 
regional standards, but where certain blower-coil combinations that 
include the outdoor model do meet regional standards, can be installed 
in the SE or SW region. DOE's guidance states that ``In order to be 
installed in the SE or SW region, the outdoor unit must have at least 
one coil-only combination that is compliant with the regional standard 
applicable at the time of installation.''
    As background, DOE notes that it finalized provisions related to 
this issue in a June 2016 Test Procedure Final Rule (81 FR 36992, June 
8, 2016) with minor revisions in a January 2017 Test Procedure Final 
Rule (82 FR 1426, January 5, 2017); a July 2016 Enforcement Final Rule 
(81 FR 45387, July 14, 2016); and a January 2017 Energy Conservation 
Standards Direct Final Rule (82 FR 1786, January 6, 2017). These 
provisions were based on consensus recommendations by two ASRAC Working 
Groups--a Regional Standards Enforcement Working Group (``Enforcement 
WG'') that concluded on October 24, 2014 (See final report: Docket No. 
EERE-2011-BT-CE-0077, No. 70), and a Central Air Conditioner and Heat 
Pump Energy Conservation Standards Working Group (``ECS WG'') that 
concluded on January 19, 2016 (See term sheet: Docket No. EERE-2014-BT-
STD-0048, No. 76).
    The July 2016 Enforcement Final Rule adopted several provisions of 
relevance here, with a focus on enforcement of the existing energy 
conservation standards:
     10 CFR 429.102(c)(4) contains provisions regarding what a 
``product installed in violation'' includes, specifying, among other 
things: ``(i) A complete central air conditioning system that is not 
certified as a complete system that meets the applicable standard. 
Combinations that were previously validly certified may be installed 
after the manufacturer has discontinued the combination, provided the 
combination meets the currently applicable standard. . . . [and] (iii) 
An outdoor unit that is part of a certified combination rated less than 
the standard applicable in the region in which it is installed.'' 81 FR 
45387, 45393-45394.
     10 CFR 429.158(a) specifies that if DOE determines a model 
of outdoor unit fails to meet the applicable regional standard(s) when 
tested in a combination certified by the same manufacturer, then the 
outdoor unit basic model will be deemed noncompliant with the regional 
standard(s). 81 FR 45387, 45397.
     10 CFR 430.32(c)(3)-(4) provides that any outdoor unit 
model that has a certified combination with a rating below 14 SEER 
cannot be installed in either the southern or southwest region. 81 FR 
45387, 45391.
    The June 2016 TP Final Rule adopted several certification 
provisions of relevance here, with a focus on the amended energy 
conservation standards recommended by the ECS WG. In particular, the 
June 2016 TP Final Rule noted that the ECS WG recommended energy 
conservation standards for central air conditioners based on coil-only 
ratings. 81 FR 36992, 37002. (June 8, 2016). The recommended standard 
levels for split system air conditioners may very well have been higher 
if they had been based on blower-coil ratings. For example, the 
recommended standard levels for split system heat pumps, which are 
based on blower-coil ratings, are approximately one point higher than 
those for split system air conditioners.
    In addition, the ECS WG recommended that DOE implement the 
requirement that every single-split air conditioner combination 
distributed in commerce must be rated, and that every single-stage and 
two-stage condensing (outdoor) unit distributed in commerce (other than 
a condensing unit for a 1-to-1 mini split) must have at least 1 coil-
only rating that is representative of the least efficient coil 
distributed in commerce with a particular condensing unit. Every 
condensing unit distributed in commerce must have at least 1 tested 
combination, and for single-stage and two-stage condensing units (other 
than condensing units for a 1-to-1 mini split) this must be a coil-only 
combination. (Docket No. EERE-2014-BT-STD-0048, No. 76, Recommendation 
#7) In the June 2016 Final Rule, DOE adopted these recommendations 
along with regional limitations for represented values of individual 
combinations:
     10 CFR 429.16(a)(1) contains provisions for required 
represented values, stating that for single-split system AC with 
single-stage or two-stage compressor, every individual combination 
distributed in commerce must be rated as a coil-only combination. For 
each model of outdoor unit, this must include at least one coil-only 
value that is representative of the least efficient combination 
distributed in commerce with that particular model of outdoor unit. 
Additional blower-coil representations are allowed for any applicable 
individual combinations, if distributed in commerce. 81 FR 36992, 
37002.
     10 CFR 429.16(b)(2)(i) specifies that for each basic model 
of single-split system AC with single-stage or two-stage compressor, 
the model of outdoor unit must be tested with a model of coil-only 
indoor unit. 81 FR 36992, 37002.
     10 CFR 429.16(a)(4)(i) [as modified in the January 2017 TP 
Final Rule] states that a basic model may only be certified as 
compliant with a regional standard if all individual combinations 
within that basic model meet the

[[Page 16848]]

regional standard for which it is certified, and that a model of 
outdoor unit that is certified below a regional standard can only be 
rated and certified as compliant with a regional standard if the model 
of outdoor unit has a unique model number and has been certified as a 
different basic model for distribution in each region. 81 FR 36992, 
37012 [as 10 CFR 429.16(a)(3)(i)]; 82 FR 1426.
    DOE notes that the July 2016 Enforcement Final Rule stated that the 
adopted provisions in 10 CFR 430.32(c)(3)-(4) were meant to be 
complementary to the regional limitations adopted in the June 2016 TP 
Final Rule at 10 CFR 429.16(a)(3)(i) [now 10 CFR 429.16(a)(4)(i)]. 81 
FR 45387, 45391. In the January 2017 CAC DFR, DOE adopted additional 
language in 10 CFR 430.32 relevant to the amended standards:
     10 CFR 430.32(c)(6)(ii) provides that any outdoor unit 
model that has a certified combination with a rating below the 
applicable standard level(s) for a region cannot be installed in that 
region. The least-efficient combination of each basic model must comply 
with this standard. 82 FR 1786, 1857.
    Finally, DOE notes that the general enforcement provisions in 
Subpart C to part 429 also apply to CAC standards (both national and 
regional), including:
     10 CFR 429.102(a)(1), specifying that the failure of a 
manufacturer to properly certify covered products in accordance with 10 
CFR 429.12 and 429.14 through 429.62 is a prohibited act subject to 
enforcement action.
    Taken together, the regional standards, certification, and 
enforcement provisions require that, in order to comply with a regional 
standard, the least efficient combination of each basic model must 
comply. 10 CFR 430.32(c)(6)(ii). Further, each basic model of single-
split system AC with single-stage or two-stage compressor must include 
a represented value for a coil-only combination representative of the 
least efficient combination distributed in commerce with the model of 
outdoor unit, and each model of outdoor unit must be tested with a 
model of coil-only indoor unit. (10 CFR 429.16(a)(1) and 
429.16(b)(2)(i)). While manufacturers can create a regional-specific 
basic model under 10 CFR 429.16(a)(4)(i), such a basic model must still 
be certified properly according to the other provisions in that 
section. As such, in order to comply with a regional standard, a 
regional-specific basic model of single-split system AC with single-
stage or two-stage compressor must include at least one coil-only 
combination that complies with the regional standard. Failure to 
certify a regional-specific basic model according to the provisions in 
10 CFR 429.16(a)(1) and 429.16(b)(2)(i) is a prohibited act under 10 
CFR 429.102(a)(1).
    Similarly, while 10 CFR 429.102(c)(4)(i) states that combinations 
that were previously validly certified may be installed after the 
manufacturer has discontinued the combination, provided the combination 
meets the currently applicable standard. The provision at 10 CFR 
429.102(c)(4)(i) was designed to allow sell-through of inventory that 
manufacturers had discontinued for reasons other than non-compliance 
with a regional standard. 81 FR 45387, 45393. It was not intended, nor 
in the light of all other provisions can it be read, as allowing 
installation of models of outdoor unit that do not comply with the 
applicable regional standard at the time of installation (i.e., have no 
combinations of coil-only units that comply with the amended regional 
standards, which, as stated previously, were developed based on coil-
only ratings).
    Based on this background, the CAC regional guidance states in part:
    In general, a basic model may be certified as compliant with a 
regional standard (and, as of January 1, 2023, meets the applicable 
amended regional standard) only if all individual combinations within 
that basic model meet the regional standard for which it is certified. 
All individual model combinations within a basic model must include, 
for single-split-system AC with single-stage or two-stage compressor 
(including space-constrained and SDHV systems), a coil-only combination 
representative of the least-efficient combination in which the specific 
outdoor unit is distributed in commerce. See 10 CFR 429.16(a)(1); 
429.16(a)(4)(i); 430.32(c)(6).
    A manufacturer may sell an outdoor unit of identical design in the 
SE and SW regions, if the manufacturer separates the basic model (i.e. 
outdoor unit model) into different basic models with unique model 
numbers for distribution in each region, provided that the basic models 
for the SE and SW regions: (1) Do not include any individual 
combinations that are not compliant with the regional standard 
applicable at the time of installation; and (2) include at least one 
coil-only combination that is representative of the least-efficient 
combination in which the specific outdoor unit is distributed in 
commerce. Id.
    DOE notes that the install-through provisions in 10 CFR 
429.102(c)(4)(i) allows existing stock of discontinued basic model 
combinations to be installed in the SE or SW regions as long as they 
were previously validly certified as compliant to the regional 
standards applicable at the time of installation. DOE further notes 
that the term ``previously validly certified'' means that all 
combinations within the basic model must show compliance with the 
regional standard applicable at the time of installation, including, 
for single-split-system AC with single-stage or two-stage compressor 
(including space-constrained and SDHV systems), a coil-only combination 
representative of the least-efficient combination in which the specific 
outdoor unit is distributed in commerce, in order for the install-
through provisions to apply.
    DOE proposes to add additional direction to the regulatory text in 
10 CFR 429.16(a)(1) and (a)(4)(i), 10 CFR 429.102(c)(4)(i) and (iii), 
and 10 CFR 430.32(c)(6)(ii) to more explicitly cross-reference the 
existing regulatory text to clarify the interplay of the existing 
requirements and reinforce the guidance.
    In addition, DOE notes that the table in 10 CFR 429.16(a)(1) states 
that the required coil-only value must be ``representative of the least 
efficient combination distributed in commerce with that particular 
model of outdoor unit'' (emphasis added). Sections 429.140 through 
429.158 provide enforcement procedures specific to regional standards, 
10 CFR 429.142 includes records retention of information regarding 
sales of outdoor units, indoor units, and single-package units, and 10 
CFR 429.144 specifies requirements for records requests. When 
determining if a model of indoor unit is distributed in commerce with a 
particular model of outdoor unit, DOE may review catalogs, product 
literature, installation instructions, and advertisements, and may also 
request sales records.
    Finally, 10 CFR 429.158 discusses products determined noncompliant 
with regional standards. Paragraphs (a) and (b) cross-reference 10 CFR 
429.102(c), stating that the certifying manufacturer is liable for 
distribution of noncompliant units in commerce. DOE notes that 10 CFR 
429.102(c) refers to distributors, contractors, and dealers, while 10 
CFR 429.102(a)(10) states that it is prohibited ``for any manufacturer 
or private labeler to knowingly sell a product to a distributor, 
contractor, or dealer with knowledge that the entity routinely violates 
any regional standard applicable to the product.'' Therefore, DOE 
proposes that 10 CFR 429.158(a)-(b) cross-reference 10 CFR 
429.102(a)(10) rather than 10 CFR 429.102(c).

[[Page 16849]]

    DOE requests comment on its proposals to the regulatory text in 10 
CFR part 429, and in particular, whether they clarify the requirements 
and align with DOE's issued guidance or whether additional 
clarification is needed.

E. Test Procedure Costs and Impact

    As discussed, DOE's existing test procedures for CAC/HPs appear at 
appendix M and appendix M1 (both titled ``Uniform Test Method for 
Measuring the Energy Consumption of Central Air Conditioners and Heat 
Pumps''). In this NOPR, DOE proposes to amend the existing test 
procedure for CACs and HPs to provide additional detail and instruction 
to ensure the representativeness of the test procedure and to reduce 
potential burden. As discussed, DOE is proposing limited amendments to 
appendix M1, which is the required test procedure beginning January 1, 
2023.
    DOE has tentatively determined that the proposed amendments in this 
NOPR would improve the representativeness, accuracy, and 
reproducibility of the test results, and they would not be unduly 
burdensome for manufacturers to conduct or result in increased testing 
cost as compared to the current test procedure.
    The proposed amendment to the wet bulb temperature maximum for the 
5 [deg]F ambient temperature condition, discussed in section III.C.2, 
would amend the condition from 3 [deg]F to 4 [deg]F. This change is 
proposed based, in part, on feedback from manufacturers that the 
proposed change to 4 [deg]F would be easier to achieve than 3 [deg]F. 
As such, DOE does not anticipate that this provision would increase the 
burden of conducting testing under appendix M1.
    With regards to the additional test procedure proposals introduced 
in sections III.B and III.C of this NOPR, DOE does not believe that 
these will cause manufacturers to incur any additional test procedure 
costs. The proposals to (a) define revised fan wattages for low-stage 
testing of two-stage coil-only units, and (b) revise the equations for 
full-capacity operation of variable-speed heat pumps at and above 45 
[deg]F affect calculations rather than testing. The proposals for 
variable-speed coil-only air conditioners and heat pumps provide 
instructions for testing such models that are currently the subject of 
test procedure waivers. The proposals to (a) revise text regarding 
variation of fan speed with ambient temperature, (b) explicitly 
indicate that the airflow measurement apparatus fan should be adjusted 
to maintain constant airflow for certain models, and (c) clarify that 
the instructions on a label affixed to the unit take precedence over 
the instructions shipped with the unit provide additional instruction 
to improve consistency of testing but would not increase either the 
number of tests or the duration of tests. Finally, the proposed changes 
in 10 CFR part 429 neither modify the test procedure nor increase the 
number of units that would be required to be tested. Thus, DOE does not 
anticipate these additional procedures would cause any increased test 
procedure costs.

F. Compliance Date and Waivers

    EPCA prescribes that, if DOE amends a test procedure, all 
representations of energy efficiency and energy use, including those 
made on marketing materials and product labels, must be made in 
accordance with that amended test procedure, beginning 180 days after 
publication of such a test procedure final rule in the Federal 
Register. (42 U.S.C. 6293(c)(2))
    If DOE were to publish an amended test procedure EPCA provides an 
allowance for individual manufacturers to petition DOE for an extension 
of the 180-day period if the manufacturer may experience undue hardship 
in meeting the deadline. (42 U.S.C. 6293(c)(3)) To receive such an 
extension, petitions must be filed with DOE no later than 60 days 
before the end of the 180-day period and must detail how the 
manufacturer will experience undue hardship. (Id.)
    Upon the compliance date of test procedure provisions of an amended 
test procedure, should DOE issue a such an amendment, any waivers that 
had been previously issued and are in effect that pertain to issues 
addressed by such provisions are terminated. 10 CFR 430.27(h)(3). 
Recipients of any such waivers would be required to test the products 
subject to the waiver according to the amended test procedure as of the 
compliance date of the amended test procedure. The amendments proposed 
in this document pertain to issues addressed by waivers granted to GD 
Midea Heating and Ventilating Equipment Co., (83 FR 56065, Case No. 
2017-013), and TCL AC (84 FR 11941, Case No. 2018-009); and interim 
waivers granted to Aerosys (83 FR 24762, Case No. 2017-008), LG 
Electronics (85 FR 40272, Case No. 2019-008), and Goodman (86 FR 40534, 
Case No. 2021-001). To the extent such waivers and interim waivers 
permit the petitioner to test according to an alternate test procedure 
to appendix M, such waivers and interim waivers will terminate on the 
date testing is required according to appendix M1 (i.e., January 1, 
2023), independent of this rulemaking. To the extent that such waivers 
and interim waivers permit the petitioner to test according to an 
alternate test procedure to appendix M1 at such time as testing is 
required according to appendix M1, such waivers and interim waivers 
would terminate on January 1, 2023, if the amendments in this NOPR are 
adopted as proposed.
    DOE notes that the waiver issued to Johnson Controls (83 FR 12735, 
Case No. CAC-051; 84 FR 52489, Case No. CAC-050) and interim waiver 
granted to National Comfort Products (83 FR 24754, Case No. 2017-008) 
will terminate on January 1, 2023, the date beginning which testing 
according to appendix M1 is required, independent of this NOPR.

IV. Procedural Issues and Regulatory Review

A. Review Under Executive Order 12866

    The Office of Management and Budget (``OMB'') has determined that 
this test procedure rulemaking does not constitute a ``significant 
regulatory action'' under section 3(f) of Executive Order (``E.O.'') 
12866, Regulatory Planning and Review, 58 FR 51735 (Oct. 4, 1993). 
Accordingly, this action was not subject to review under the Executive 
order by the Office of Information and Regulatory Affairs (``OIRA'') in 
OMB.

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: http://energy.gov/gc/office-general-counsel">energy.gov/gc/office-general-counsel.
    DOE reviewed this proposed rule under the provisions of the 
Regulatory Flexibility Act and the procedures and policies published on 
February 19, 2003. DOE certifies that the proposed rule, if adopted, 
would not have significant economic impact on a substantial number of 
small entities.

[[Page 16850]]

The factual basis of this certification is set forth in the following 
paragraphs.
    Under 42 U.S.C. 6293, the statute sets forth the criteria and 
procedures DOE must follow when prescribing or amending test procedures 
for covered products. EPCA requires that any test procedures prescribed 
or amended under this section must be reasonably designed to produce 
test results which measure energy efficiency, energy use or estimated 
annual operating cost of a covered product during a representative 
average use cycle or period of use and not be unduly burdensome to 
conduct. (42 U.S.C. 6293(b)(3))
    DOE is proposing a limited number of amendments to the test 
procedure for central air conditioners and heat pumps (``CAC/HPs'') to 
address specific issues that have been raised in test procedure waivers 
regarding appendix M1 to subpart B of 10 CFR part 430.
    In this NOPR, DOE proposes the following updates to the test 
procedure for CACs/HPs:
    1. Update default fan power for coil-only CACs and HPs that can 
utilize different fan speeds and the 75% intermediate airflow.
    2. Define ``Communicating Variable-speed Coil-only Central Air 
Conditioner or Heat Pump'' and prescribing an appropriate test 
procedure.
    3. Add the control system capability to adjust air volume rate as a 
function of outdoor air temperature for blower coil systems with 
multiple-speed or variable-speed indoor fans.
    4. Amend the wet bulb test condition for the 5 [deg]F dry, outdoor 
ambient test to have a 4 [deg]F maximum.
    5. Add direction to prioritize the instructions presented in the 
label attached to the unit over the instructions included in the 
installation instructions shipped with the unit.
    6. Add specific instruction to adjust the exhaust fan speed to 
achieve a constant cooling full-load air volume rate through the 
airflow measurement apparatus.
    7. Revise the equations representing full-capacity performance of 
variable-speed heat pumps for the temperature range above 45 [deg]F to 
be more consistent with field operation.
    8. Providing additional direction regarding the regional standard 
requirements in 10 CFR part 429.
    For manufacturers of CACs/HPs, the Small Business Administration 
(``SBA'') has set a size threshold, which defines those entities 
classified as ``small businesses'' for the purposes of the statute. DOE 
used the SBA's small business size standards to determine whether any 
small entities would be subject to the requirements of the rule. See 13 
CFR part 121. The equipment covered by this rule is classified under 
North American Industry Classification System (``NAICS'') code 
333415,\21\ ``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. 
DOE identified manufacturers using DOE's Compliance Certification 
Database (``CCD''),\22\ the AHRI database,\23\ the California Energy 
Commission's Modernized Appliance Efficiency Database System 
(``MAEDbS''),\24\ the ENERGY STAR Product Finder database,\25\ and the 
prior CAC/HP rulemakings. DOE used the publicly available information 
and subscription-based market research tools (e.g., reports from Dun & 
Bradstreet \26\) to identify 33 original equipment manufacturers 
(``OEMs'') of the covered equipment. Of the 33 OEMs, DOE identified 
eight domestic manufacturers of CACs/HPs that meet the SBA definition 
of a ``small business.''
---------------------------------------------------------------------------

    \21\ 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 October 1, 2021).
    \22\ DOE's Compliance Certification Database is available at: 
www.regulations.doe.gov/ccms (last accessed October 11, 2021).
    \23\ The AHRI Database is available at: www.ahridirectory.org/ 
(last accessed October 1, 2021).
    \24\ California Energy Commission's MAEDbS is available at 
cacertappliances.energy.ca.gov/Pages/ApplianceSearch.aspx (last 
accessed October 1, 2021).
    \25\ The ENERGY STAR Product Finder database is available at 
energystar.gov/productfinder/ (last accessed September 22, 2021).
    \26\ app.dnbhoovers.com.
---------------------------------------------------------------------------

    This NOPR proposes amendments to the test procedure for CAC/HP for 
which compliance is not required until January 1, 2023. As discussed in 
more detail in section III.E of this document, DOE has initially 
determined that the proposed amendments to the test procedure would not 
require retesting or re-rating, with the potential exception of 
variable-speed coil-only units. While DOE believes the variable-speed 
coil-only units will be isolated to a very small fraction of models 
distributed in commerce (i.e., less than 1 percent based on 
manufacturer representations in DOE's current Compliance Management 
Database), a manufacturer will have need to ensure their 
representations are made in accordance with these amendments if 
finalized. DOE notes that none of the variable-speed coil-only basic 
models certified currently with DOE are manufactured by small 
manufacturers. Additionally, the test procedure amendments would not 
result in any change in burden associated the DOE test procedure for 
CACs/HP. Therefore, DOE initially concludes that the test procedure 
amendments proposed in this NOPR would not have a ``significant 
economic impact on a substantial number of small entities,'' and that 
the preparation of an IRFA is not warranted. DOE will transmit the 
certification and supporting statement of factual basis to the Chief 
Counsel for Advocacy of the Small Business Administration for review 
under 5 U.S.C. 605(b). DOE welcomes comment on the Regulatory 
Flexibility certification conclusion.

C. Review Under the Paperwork Reduction Act of 1995

    Manufacturers of CAC/HP must certify to DOE that their products 
comply with any applicable energy conservation standards. To certify 
compliance, manufacturers must first obtain test data for their 
products according to the DOE test procedures, including any amendments 
adopted for those test procedures. DOE has established regulations for 
the certification and recordkeeping requirements for all covered 
consumer products and commercial equipment, including CACs/HPs. (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.
    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 CAC/HP. DOE has determined that this 
proposed rule falls into a class of actions that are categorically 
excluded from review under the National

[[Page 16851]]

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 (Aug. 4, 1999) 
imposes certain requirements on agencies formulating and implementing 
policies or regulations that preempt State law or that have federalism 
implications. The Executive order requires agencies to examine the 
constitutional and statutory authority supporting any action that would 
limit the policymaking discretion of the States and to carefully assess 
the necessity for such actions. The Executive order also requires 
agencies to have an accountable process to ensure meaningful and timely 
input by State and local officials in the development of regulatory 
policies that have federalism implications. On March 14, 2000, DOE 
published a statement of policy describing the intergovernmental 
consultation process it will follow in the development of such 
regulations. 65 FR 13735. DOE has examined this proposed rule and has 
determined that it would not have a substantial direct effect on the 
States, on the relationship between the national government and the 
States, or on the distribution of power and responsibilities among the 
various levels of government. EPCA governs and prescribes Federal 
preemption of State regulations as to energy conservation for the 
products that are the subject of this proposed rule. States can 
petition DOE for exemption from such preemption to the extent, and 
based on criteria, set forth in EPCA. (42 U.S.C. 6297(d)) No further 
action is required by Executive Order 13132.

F. Review Under Executive Order 12988

    Regarding the review of existing regulations and the promulgation 
of new regulations, section 3(a) of Executive Order 12988, ``Civil 
Justice Reform,'' 61 FR 4729 (Feb. 7, 1996), imposes on Federal 
agencies the general duty to adhere to the following requirements: (1) 
Eliminate drafting errors and ambiguity, (2) write regulations to 
minimize litigation, (3) provide a clear legal standard for affected 
conduct rather than a general standard, and (4) promote simplification 
and burden reduction. Section 3(b) of Executive Order 12988 
specifically requires that executive agencies make every reasonable 
effort to ensure that the regulation (1) clearly specifies the 
preemptive effect, if any, (2) clearly specifies any effect on existing 
Federal law or regulation, (3) provides a clear legal standard for 
affected conduct while promoting simplification and burden reduction, 
(4) specifies the retroactive effect, if any, (5) adequately defines 
key terms, and (6) addresses other important issues affecting clarity 
and general draftsmanship under any guidelines issued by the Attorney 
General. Section 3(c) of Executive Order 12988 requires Executive 
agencies to review regulations in light of applicable standards in 
sections 3(a) and 3(b) to determine whether they are met, or it is 
unreasonable to meet one or more of them. DOE has completed the 
required review and determined that, to the extent permitted by law, 
the proposed rule meets the relevant standards of Executive Order 
12988.

G. Review Under the Unfunded Mandates Reform Act of 1995

    Title II of the Unfunded Mandates Reform Act of 1995 (``UMRA'') 
requires each Federal agency to assess the effects of Federal 
regulatory actions on State, local, and Tribal governments and the 
private sector. Public Law 104-4, sec. 201 (codified at 2 U.S.C. 1531). 
For a proposed regulatory action likely to result in a rule that may 
cause the expenditure by State, local, and Tribal governments, in the 
aggregate, or by the private sector of $100 million or more in any one 
year (adjusted annually for inflation), section 202 of UMRA requires a 
Federal agency to publish a written statement that estimates the 
resulting costs, benefits, and other effects on the national economy. 
(2 U.S.C. 1532(a), (b)) The UMRA also requires a Federal agency to 
develop an effective process to permit timely input by elected officers 
of State, local, and Tribal governments on a proposed ``significant 
intergovernmental mandate,'' and requires an agency plan for giving 
notice and opportunity for timely input to potentially affected small 
governments before establishing any requirements that might 
significantly or uniquely affect small governments. On March 18, 1997, 
DOE published a statement of policy on its process for 
intergovernmental consultation under UMRA. 62 FR 12820; also available 
at http://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%.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

[[Page 16852]]

``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 CAC/HPs is not a significant 
regulatory action under Executive Order 12866. Moreover, it would not 
have a significant adverse effect on the supply, distribution, or use 
of energy, nor has it been designated as a significant energy action by 
the Administrator of OIRA. Therefore, it is not a significant energy 
action, and, accordingly, DOE has not prepared a Statement of Energy 
Effects.

L. Review Under Section 32 of the Federal Energy Administration Act of 
1974

    Under section 301 of the Department of Energy Organization Act 
(Pub. L. 95-91; 42 U.S.C. 7101), DOE must comply with section 32 of the 
Federal Energy Administration Act of 1974, as amended by the Federal 
Energy Administration Authorization Act of 1977. (15 U.S.C. 788; 
``FEAA'') Section 32 essentially provides in relevant part that, where 
a proposed rule authorizes or requires use of commercial standards, the 
notice of proposed rulemaking must inform the public of the use and 
background of such standards. In addition, section 32(c) requires DOE 
to consult with the Attorney General and the Chairman of the Federal 
Trade Commission (``FTC'') concerning the impact of the commercial or 
industry standards on competition.
    The proposed modifications to the test procedure for CACs/HPs would 
maintain the incorporation of testing methods contained in certain 
sections of the following commercial standards: ANSI/AHRI 210/240-2008 
with Addenda 1 and 2, (``AHRI 210/240-2008''): 2008 Standard for 
Performance Rating of Unitary Air-Conditioning & Air-Source Heat Pump 
Equipment, ANSI approved October 27, 2011; ANSI/AHRI 1230-2010 with 
Addendum 2, (``AHRI 1230-2010''): 2010 Standard for Performance Rating 
of Variable Refrigerant Flow (VRF) Multi-Split Air-Conditioning and 
Heat Pump Equipment, ANSI approved August 2, 2010; ANSI/ASHRAE 23.1-
2010, (``ASHRAE 23.1-2010''): Methods of Testing for Rating the 
Performance of Positive Displacement Refrigerant Compressors and 
Condensing Units that Operate at Subcritical Temperatures of the 
Refrigerant, ANSI approved January 28, 2010; ANSI/ASHRAE Standard 37-
2009, (``ANSI/ASHRAE 37-2009''), Methods of Testing for Rating 
Electrically Driven Unitary Air-Conditioning and Heat Pump Equipment, 
ANSI approved June 25, 2009; ANSI/ASHRAE 41.1-2013, (``ANSI/ASHRAE 
41.1-2013''): Standard Method for Temperature Measurement, ANSI 
approved January 30, 2013; ANSI/ASHRAE 41.6-2014, (``ASHRAE 41.6-
2014''): Standard Method for Humidity Measurement, ANSI approved July 
3, 2014; ANSI/ASHRAE 41.9-2011, (``ASHRAE 41.9-2011''): Standard 
Methods for Volatile-Refrigerant Mass Flow Measurements Using 
Calorimeters, ANSI approved February 3, 2011; ANSI/ASHRAE 116-2010, 
(``ASHRAE 116-2010''): Methods of Testing for Rating Seasonal 
Efficiency of Unitary Air Conditioners and Heat Pumps, ANSI approved 
February 24, 2010; ANSI/ASHRAE 41.2-1987 (Reaffirmed 1992), (``ASHRAE 
41.2-1987 (RA 1992)''): ``Standard Methods for Laboratory Airflow 
Measurement'', ANSI approved April 20, 1992; and ANSI/AMCA 210-2007, 
ANSI/ASHRAE 51-2007, (``AMCA 210-2007'') Laboratory Methods of Testing 
Fans for Certified Aerodynamic Performance Rating, ANSI approved August 
17, 2007.
    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 it was 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

    The following standard was previously approved for incorporation by 
reference in appendix M1 where it appears and no change is proposed:
    ANSI/ASHRAE Standard 37-2009, Methods of Testing for Rating 
Electrically Driven Unitary Air-Conditioning and Heat Pump Equipment, 
ANSI approved June 25, 2009;

V. Public Participation

A. 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.\27\ Interested parties may submit 
comments using any of the methods described in the ADDRESSES section at 
the beginning of this document.
---------------------------------------------------------------------------

    \27\ DOE has historically provided a 75-day comment period for 
test procedure NOPRs pursuant to the North American Free Trade 
Agreement, U.S.-Canada-Mexico (``NAFTA''), Dec. 17, 1992, 32 I.L.M. 
289 (1993); the North American Free Trade Agreement Implementation 
Act, Public Law 103-182, 107 Stat. 2057 (1993) (codified as amended 
at 10 U.S.C.A. 2576) (1993) (``NAFTA Implementation Act''); and 
Executive Order 12889, ``Implementation of the North American Free 
Trade Agreement,'' 58 FR 69681 (Dec. 30, 1993). However, on July 1, 
2020, the Agreement between the United States of America, the United 
Mexican States, and the United Canadian States (``USMCA''), Nov. 30, 
2018, 134 Stat. 11 (i.e., the successor to NAFTA), went into effect, 
and Congress's action in replacing NAFTA through the USMCA 
Implementation Act, 19 U.S.C. 4501 et seq. (2020), implies the 
repeal of E.O. 12889 and its 75-day comment period requirement for 
technical regulations. Thus, the controlling laws are EPCA and the 
USMCA Implementation Act. Consistent with EPCA's public comment 
period requirements for consumer products, the USMCA only requires a 
minimum comment period of 60 days. Consequently, DOE now provides a 
60-day public comment period for test procedure NOPRs.
---------------------------------------------------------------------------

    Submitting comments via www.regulations.gov. The 
www.regulations.gov web page will require you to provide your name and 
contact information. Your contact information will be viewable to DOE 
Building Technologies staff only. Your contact information will not be 
publicly viewable except for your first and last names, organization 
name (if any), and submitter representative name (if any). If your 
comment is not processed properly because of technical difficulties, 
DOE will use this information to contact you. If DOE cannot read your 
comment due to technical difficulties and cannot contact you for 
clarification, DOE may not be able to consider your comment.
    However, your contact information will be publicly viewable if you 
include it in the comment or in any documents attached to your comment. 
Any information that you do not want to be publicly viewable should not 
be included in your comment, nor in any document attached to your 
comment. 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

[[Page 16853]]

secrets and commercial or financial information (hereinafter referred 
to as Confidential Business Information (``CBI'')). Comments submitted 
through www.regulations.gov cannot be claimed as CBI. Comments received 
through the website will waive any CBI claims for the information 
submitted. For information on submitting CBI, see the Confidential 
Business Information section.
    DOE processes submissions made through www.regulations.gov before 
posting. Normally, comments will be posted within a few days of being 
submitted. However, if large volumes of comments are being processed 
simultaneously, your comment may not be viewable for up to several 
weeks. Please keep the comment tracking number that www.regulations.gov 
provides after you have successfully uploaded your comment.
    Submitting comments via email. Comments and documents submitted via 
email also will be posted to www.regulations.gov. If you do not want 
your personal contact information to be publicly viewable, do not 
include it in your comment or any accompanying documents. Instead, 
provide your contact information on a cover letter. Include your first 
and last names, email address, telephone number, and optional mailing 
address. The cover letter will not be publicly viewable as long as it 
does not include any comments.
    Include contact information each time you submit comments, data, 
documents, and other information to DOE. No faxes will be accepted.
    Comments, data, and other information submitted to DOE 
electronically should be provided in PDF (preferred), Microsoft Word or 
Excel, WordPerfect, or text (ASCII) file format. Provide documents that 
are not secured, written in English and free of any defects or viruses. 
Documents should not contain special characters or any form of 
encryption and, if possible, they should carry the electronic signature 
of the author.
    Campaign form letters. Please submit campaign form letters by the 
originating organization in batches of between 50 to 500 form letters 
per PDF or as one form letter with a list of supporters' names compiled 
into one or more PDFs. This reduces comment processing and posting 
time.
    Confidential Business Information. Pursuant to 10 CFR 1004.11, any 
person submitting information that he or she believes to be 
confidential and exempt by law from public disclosure should submit via 
email two well-marked copies: One copy of the document marked 
confidential including all the information believed to be confidential, 
and one copy of the document marked non-confidential with the 
information believed to be confidential deleted. DOE will make its own 
determination about the confidential status of the information and 
treat it according to its determination.
    It is DOE's policy that all comments may be included in the public 
docket, without change and as received, including any personal 
information provided in the comments (except information deemed to be 
exempt from public disclosure).

B. 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:
    (1) DOE requests comment on its proposal to specify a reduced 
default fan power coefficient and default fan heat coefficient at part-
load airflows in the calculations of SEER2 and HSPF2 for ducted two-
stage coil-only systems. DOE requests comment on the specific default 
fan power coefficients and default fan heat coefficients proposed. If 
the proposed values are not appropriate, DOE seeks data to support 
selection of alternative values. Additionally, DOE requests comment on 
whether a single default fan power coefficient (and default fan heat 
coefficient) should be used for each product class group regardless of 
the actual air volume rate used for low-stage tests, or whether one of 
the alternative approaches discussed in the NOPR should be considered, 
or any other alternative. If an alternative approach should be used, 
DOE requests details indicating how such an alternative should be 
implemented, and justification for its use rather than the proposed 
approach. See section III.B.1.
    (2) DOE requests comment on its proposals related to test 
procedures for variable-speed coil-only CAC/HPs and on its proposed 
definitions for variable-speed communicating and non-communicating 
coil-only CAC/HPs. See section III.B.2.
    (3) DOE requests comment on its proposal to clarify the language 
for required represented values of coil-only CACs found in the table at 
10 CFR 429.16(a)(1). See section III.B.3.
    (4) DOE requests comment on its planned approach to require the 
coil-only rating requirement for space-constrained air conditioners and 
heat pumps. DOE requests shipment and/or installation data for space-
constrained systems to clarify the characteristics of representative 
installations. See section III.B.3.
    (5) DOE requests comments on its proposal to add language 
clarifying how to implement variation of blower speed for different 
ambient temperature test conditions. See section III.C.1.
    (6) DOE seeks comment on its proposal to amend the wet bulb 
temperature condition for the H4 heating tests from the existing 3 
[deg]F maximum temperature to a maximum temperature of 4 [deg]F. See 
section III.C.2.
    (7) DOE requests comment on the proposed alignment of the VRF and 
non-VRF test procedures when it comes to instruction precedence. See 
section III.C.3.
    (8) DOE requests comment on its proposal to add more specific 
direction to step 7 of sections 3.1.4.1.1, 3.1.4.2, and 3.1.4.4.3. See 
section III.C.4.
    (9) DOE requests comment on the proposed change to the full-
capacity performance equations for variable-speed heat pumps in the 
ambient temperature range above 45 [deg]F, adjusting the equations for 
capacity and power by the ratio of capacity and power, respectively, 
associated with H1N and H12 operation. See section III.C.5.
    (10) DOE requests comment on its proposals to the regulatory text 
in 10 CFR part 429. See section III.D.1.

C. Participation in the Webinar

    The time and date of the webinar are listed in the DATES section at 
the beginning of this document. If no participants register for the 
webinar, it will be cancelled.
    Webinar registration information, participant instructions, and 
information about the capabilities available to webinar participants 
will be published on DOE's website: https://www1.eere.energy.gov/buildings/appliance_standards/standards.aspx?productid=48&action=viewlive. Participants are 
responsible for ensuring their systems are compatible with the webinar 
software. Procedure for Submitting Prepared General Statements for 
Distribution. Any person who has an interest in the topics addressed in 
this notice, or who is representative of a group or class of persons 
that has an interest in these issues, may request an opportunity to 
make an oral presentation at the webinar. Such persons may submit to 
[email protected]. Persons who wish to speak 
should include with their request a computer file in WordPerfect, 
Microsoft Word, PDF, or text (ASCII) file format that briefly describes 
the nature of their interest in this rulemaking and the

[[Page 16854]]

topics they wish to discuss. Such persons should also provide a daytime 
telephone number where they can be reached.
    Persons requesting to speak should briefly describe the nature of 
their interest in this rulemaking and provide a telephone number for 
contact. DOE requests persons selected to make an oral presentation to 
submit an advance copy of their statements at least two weeks before 
the webinar. At its discretion, DOE may permit persons who cannot 
supply an advance copy of their statement to participate, if those 
persons have made advance alternative arrangements with the Building 
Technologies Office. As necessary, requests to give an oral 
presentation should ask for such alternative arrangements.

D. Conduct of the Webinar

    DOE will designate a DOE official to preside at the webinar/public 
meeting and may also use a professional facilitator to aid discussion. 
The meeting will not be a judicial or evidentiary-type public hearing, 
but DOE will conduct it in accordance with section 336 of EPCA (42 
U.S.C. 6306). A court reporter will be present to record the 
proceedings and prepare a transcript. DOE reserves the right to 
schedule the order of presentations and to establish the procedures 
governing the conduct of the webinar/public meeting. There shall not be 
discussion of proprietary information, costs or prices, market share, 
or other commercial matters regulated by U.S. anti-trust laws. After 
the webinar/public meeting and until the end of the comment period, 
interested parties may submit further comments on the proceedings and 
any aspect of the rulemaking.
    The webinar/public meeting will be conducted in an informal, 
conference style. DOE will present a summary of the proposals, 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 permit, as time permits, other 
participants to comment briefly on any general statements.
    At the end of all prepared statements on a topic, DOE will permit 
participants to clarify their statements briefly. Participants should 
be prepared to answer questions by DOE and by other participants 
concerning these issues. DOE representatives may also ask questions of 
participants concerning other matters relevant to this rulemaking. The 
official conducting the webinar/public meeting will accept additional 
comments or questions from those attending, as time permits. The 
presiding official will announce any further procedural rules or 
modification of the above procedures that may be needed for the proper 
conduct of the webinar/public meeting.
    A transcript of the webinar/public meeting will be included in the 
docket, which can be viewed as described in the Docket section at the 
beginning of this document. In addition, any person may buy a copy of 
the transcript from the transcribing reporter.

VI. Approval of the Office of the Secretary

    The Secretary of Energy has approved publication of this proposed 
rule.

List of Subjects

10 CFR Part 429

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

10 CFR Part 430

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

Signing Authority

    This document of the Department of Energy was signed on February 
22, 2022, by Kelly J. Speakes-Backman, Principal Deputy Assistant 
Secretary 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 February 24, 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 430 of chapter II of title 10, Code of Federal 
Regulations as set forth below:

PART 429--CERTIFICATION, COMPLIANCE, AND ENFORCEMENT FOR CONSUMER 
PRODUCTS AND COMMERCIAL AND INDUSTRIAL EQUIPMENT

0
1. The authority citation for part 429 continues to read as follows:

    Authority: 42 U.S.C. 6291-6317; 28 U.S.C. 2461 note.

0
2. Section 429.16 is amended by:
0
a. Revising the table 1 to paragraph (a)(1);
0
b. Revising paragraph (a)(4)(i); and
0
c. Revising the table in paragraph (b)(2)(i).
    The revisions read as follows:


Sec.  429.16  Central air conditioners and central air conditioning 
heat pumps.

    (a) * * *
    (1) * * *

                       Table 1 to Paragraph (a)(1)
------------------------------------------------------------------------
                                    Equipment       Required represented
           Category                subcategory             values
------------------------------------------------------------------------
Single-Package Unit...........  Single-Package AC  Every individual
                                 (including space-  model distributed in
                                 constrained).      commerce.
                                Single-Package HP
                                 (including space-
                                 constrained).

[[Page 16855]]

 
Outdoor Unit and Indoor Unit    Single-Split-      Every individual
 (Distributed in Commerce by     System AC with     combination
 OUM).                           Single-Stage or    distributed in
                                 Two-Stage          commerce. Each model
                                 Compressor         of outdoor unit must
                                 (including Space-  include a
                                 Constrained and    represented value
                                 Small-Duct, High   for at least one
                                 Velocity Systems   coil-only individual
                                 (SDHV)).           combination that is
                                                    distributed in
                                                    commerce and which
                                                    is representative of
                                                    the least efficient
                                                    combination
                                                    distributed in
                                                    commerce with that
                                                    particular model of
                                                    outdoor unit. For
                                                    that particular
                                                    model of outdoor
                                                    unit, additional
                                                    represented values
                                                    for coil-only and
                                                    blower-coil
                                                    individual
                                                    combinations are
                                                    allowed, if
                                                    distributed in
                                                    commerce.
                                Single-Split       Every individual
                                 System AC with     combination
                                 Other Than         distributed in
                                 Single-Stage or    commerce, including
                                 Two-Stage          all coil-only and
                                 Compressor         blower-coil
                                 (including Space-  combinations.
                                 Constrained and
                                 SDHV).
                                Single-Split-      Every individual
                                 System HP          combination
                                 (including Space-  distributed in
                                 Constrained and    commerce.
                                 SDHV).
                                Multi-Split,       For each model of
                                 Multi-Circuit,     outdoor unit, at a
                                 or Multi-Head      minimum, a non-
                                 Mini-Split Split   ducted ``tested
                                 System--non-SDHV   combination.'' For
                                 (including Space-  any model of outdoor
                                 Constrained).      unit also sold with
                                                    models of ducted
                                                    indoor units, a
                                                    ducted ``tested
                                                    combination.'' When
                                                    determining
                                                    represented values
                                                    on or after January
                                                    1, 2023, the ducted
                                                    ``tested
                                                    combination'' must
                                                    comprise the highest
                                                    static variety of
                                                    ducted indoor unit
                                                    distributed in
                                                    commerce (i.e.,
                                                    conventional, mid-
                                                    static, or low-
                                                    static). Additional
                                                    representations are
                                                    allowed, as
                                                    described in
                                                    paragraphs (c)(3)(i)
                                                    and (c)(3)(ii) of
                                                    this section,
                                                    respectively.
                                Multi-Split,       For each model of
                                 Multi-Circuit,     outdoor unit, an
                                 or Multi-Head      SDHV ``tested
                                 Mini-Split Split   combination.''
                                 System--SDHV.      Additional
                                                    representations are
                                                    allowed, as
                                                    described in
                                                    paragraph
                                                    (c)(3)(iii) of this
                                                    section.
Indoor Unit Only Distributed    Single-Split-      Every individual
 in Commerce by ICM.             System Air         combination
                                 Conditioner        distributed in
                                 (including Space-  commerce.
                                 Constrained and
                                 SDHV).
                                Single-Split-
                                 System Heat Pump
                                 (including Space-
                                 Constrained and
                                 SDHV).
                                Multi-Split,       For a model of indoor
                                 Multi-Circuit,     unit within each
                                 or Multi-Head      basic model, an SDHV
                                 Mini-Split Split   ``tested
                                 System--SDHV.      combination.''
                                                    Additional
                                                    representations are
                                                    allowed, as
                                                    described in section
                                                    (c)(3)(iii) of this
                                                    section.
------------------------------------------------------------------------
            Outdoor Unit with no Match             Every model of
                                                    outdoor unit
                                                    distributed in
                                                    commerce (tested
                                                    with a model of coil-
                                                    only indoor unit as
                                                    specified in
                                                    paragraph (b)(2)(i)
                                                    of this section).
------------------------------------------------------------------------

* * * * *
    (4) * * *
    (i) Regional. A basic model (model of outdoor unit) may only be 
certified as compliant with a regional standard if all individual 
combinations within that basic model meet the regional standard for 
which it is certified, including the coil-only combination as specified 
in paragraph (a)(1) of this section, as applicable. A model of outdoor 
unit that is certified below a regional standard can only be rated and 
certified as compliant with a regional standard if the model of outdoor 
unit has a unique model number and has been certified as a different 
basic model for distribution in each region, where the basic model(s) 
certified as compliant with a regional standard meet the requirements 
of the first sentence. An ICM cannot certify an individual combination 
with a rating that is compliant with a regional standard if the 
individual combination includes a model of outdoor unit that the OUM 
has certified with a rating that is not compliant with a regional 
standard. Conversely, an ICM cannot certify an individual combination 
with a rating that is not compliant with a regional standard if the 
individual combination includes a model of outdoor unit that an OUM has 
certified with a rating that is compliant with a regional standard.
* * * * *
    (b) * * *
    (2) * * *
    (i) * * *

                                         Table 2 to Paragraph (b)(2)(i)
----------------------------------------------------------------------------------------------------------------
             Category                Equipment subcategory           Must test:                   With:
----------------------------------------------------------------------------------------------------------------
Single-Package Unit..............  Single-Package AC          The individual model      N/A.
                                    (including Space-          with the lowest SEER
                                    Constrained).              (when testing in
                                   Single-Package HP           accordance with
                                    (including Space-          appendix M to subpart B
                                    Constrained).              of part 430) or SEER2
                                                               (when testing in
                                                               accordance with
                                                               appendix M1 to subpart
                                                               B of part 430).

[[Page 16856]]

 
Outdoor Unit and Indoor Unit       Single-Split-System AC     The model of outdoor      A model of coil-only
 (Distributed in Commerce by OUM).  with Single-Stage or Two-  unit.                     indoor unit.
                                    Stage Compressor
                                    (including Space-
                                    Constrained and Small-
                                    Duct, High Velocity
                                    Systems (SDHV)).
                                   Single-Split-System HP     The model of outdoor      A model of indoor unit.
                                    with Single-Stage or Two-  unit.
                                    Stage Compressor
                                    (including Space-
                                    Constrained and SDHV).
                                   Single-Split System AC or  The model of outdoor      A model of coil-only
                                    HP with Other Than         unit.                     indoor unit. If the
                                    Single-Stage or Two-                                 outdoor unit is
                                    Stage Compressor having                              distributed in commerce
                                    a coil-only individual                               in a non-communicating
                                    combination (including                               variable-speed coil-
                                    Space-Constrained and                                only combination, the
                                    SDHV).                                               tested combination must
                                                                                         be non-communicating.
                                   Single-Split System AC or  The model of outdoor      A model of indoor unit.
                                    HP with Other Than         unit.
                                    Single-Stage or Two-
                                    Stage Compressor without
                                    a coil-only individual
                                    combination (including
                                    Space-Constrained and
                                    SDHV).
                                   Multi-Split, Multi-        The model of outdoor      At a minimum, a ``tested
                                    Circuit, or Multi-Head     unit.                     combination'' composed
                                    Mini-Split Split System--                            entirely of non-ducted
                                    non-SDHV (including                                  indoor units. For any
                                    Space-Constrained).                                  models of outdoor units
                                                                                         also sold with models
                                                                                         of ducted indoor units,
                                                                                         test a second ``tested
                                                                                         combination'' composed
                                                                                         entirely of ducted
                                                                                         indoor units (in
                                                                                         addition to the non-
                                                                                         ducted combination). If
                                                                                         testing under appendix
                                                                                         M1 to subpart B of part
                                                                                         430, the ducted
                                                                                         ``tested combination''
                                                                                         must comprise the
                                                                                         highest static variety
                                                                                         of ducted indoor unit
                                                                                         distributed in commerce
                                                                                         (i.e., conventional,
                                                                                         mid-static, or low-
                                                                                         static).
                                   Multi-Split, Multi-        The model of outdoor      A ``tested combination''
                                    Circuit, or Multi-Head     unit.                     composed entirely of
                                    Mini-Split Split System--                            SDHV indoor units.
                                    SDHV.
Indoor Unit Only (Distributed in   Single-Split-System Air    A model of indoor unit..  The least efficient
 Commerce by ICM).                  Conditioner (including                               model of outdoor unit
                                    Space-Constrained and                                with which it will be
                                    SDHV).                                               paired where the least
                                                                                         efficient model of
                                                                                         outdoor unit is the
                                                                                         model of outdoor unit
                                                                                         in the lowest SEER
                                                                                         combination (when
                                                                                         testing under appendix
                                                                                         M to subpart B of part
                                                                                         430) or SEER2
                                                                                         combination (when
                                                                                         testing under appendix
                                                                                         M1 to subpart B of part
                                                                                         430) as certified by
                                                                                         the OUM. If there are
                                                                                         multiple models of
                                                                                         outdoor unit with the
                                                                                         same lowest SEER (when
                                                                                         testing under appendix
                                                                                         M to subpart B of part
                                                                                         430) or SEER2 (when
                                                                                         testing under appendix
                                                                                         M1 to subpart B of part
                                                                                         430) represented value,
                                                                                         the ICM may select one
                                                                                         for testing purposes.
                                   Single-Split-System Heat   Nothing, as long as an    ........................
                                    Pump (including Space-     equivalent air
                                    Constrained and SDHV).     conditioner basic model
                                                               has been tested. If an
                                                               equivalent air
                                                               conditioner basic model
                                                               has not been tested,
                                                               must test a model of
                                                               indoor unit.

[[Page 16857]]

 
                                   Multi-Split, Multi-        A model of indoor unit..  A ``tested combination''
                                    Circuit, or Multi-Head                               composed entirely of
                                    Mini-Split Split System--                            SDHV indoor units,
                                    SDHV.                                                where the outdoor unit
                                                                                         is the least efficient
                                                                                         model of outdoor unit
                                                                                         with which the SDHV
                                                                                         indoor unit will be
                                                                                         paired. The least
                                                                                         efficient model of
                                                                                         outdoor unit is the
                                                                                         model of outdoor unit
                                                                                         in the lowest SEER
                                                                                         combination (when
                                                                                         testing under appendix
                                                                                         M to subpart B of part
                                                                                         430) or SEER2
                                                                                         combination (when
                                                                                         testing under appendix
                                                                                         M1 to subpart B of part
                                                                                         430) as certified by
                                                                                         the OUM. If there are
                                                                                         multiple models of
                                                                                         outdoor unit with the
                                                                                         same lowest SEER
                                                                                         represented value (when
                                                                                         testing under appendix
                                                                                         M to subpart B of part
                                                                                         430) or SEER2
                                                                                         represented value (when
                                                                                         testing under appendix
                                                                                         M1 to subpart B of part
                                                                                         430), the ICM may
                                                                                         select one for testing
                                                                                         purposes.
Outdoor Unit with No Match.......  .........................  The model of outdoor      A model of coil-only
                                                               unit.                     indoor unit meeting the
                                                                                         requirements of section
                                                                                         2.2e of appendix M or
                                                                                         M1 to subpart B of part
                                                                                         430.
----------------------------------------------------------------------------------------------------------------

0
3. Section 429.102 is amended by revising paragraphs (c)(4)(i) and 
(iii) to read as follows:


Sec.  429.102  Prohibited acts subjecting persons to enforcement 
action.

* * * * *
    (c) * * *
    (4) * * *
    (i) A complete central air conditioning system that is not 
certified as a complete system that meets the applicable standard. 
Combinations that were previously validly certified may be installed 
after the manufacturer has discontinued the combination, provided all 
combinations within the basic model, including for single-split-system 
AC with single-stage or two-stage compressor at least one coil-only 
combination as specified in paragraph (a)(1) of this section, comply 
with the regional standard applicable at the time of installation.
* * * * *
    (iii) An outdoor unit that is part of a certified combination rated 
less than the standard applicable in the region in which it is 
installed or, where applicable, an outdoor unit with no certified coil-
only combination as specified in paragraph (a)(1) of this section that 
meets the standard applicable in the region in which it is installed.


Sec.  429.158  [Amended]

0
4. Section 429.158 is amended by removing ``Sec.  429.102(c)'' in 
paragraphs (a) and (b) and adding in its place ``Sec.  
429.102(b)(10)''.

PART 430--ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS

0
5. The authority citation for part 430 continues to read as follows:

    Authority: 42 U.S.C. 6291-6309; 28 U.S.C. 2461 note.

0
6. Section 430.2 is amended by revising the definition for ``Central 
air conditioner or central air conditioning heat pump'' to read as 
follows:


Sec.  430. 2  Definitions.

* * * * *
    Central air conditioner or central air conditioning heat pump means 
a product, other than a packaged terminal air conditioner, packaged 
terminal heat pump, single-phase single-package vertical air 
conditioner with cooling capacity less than 65,000 Btu/h, single-phase 
single-package vertical heat pump with cooling capacity less than 
65,000 Btu/h, computer room air conditioner, or unitary dedicated 
outdoor air system as these equipment categories are defined at 10 CFR 
431.92, which is powered by single phase electric current, air cooled, 
rated below 65,000 Btu per hour, not contained within the same cabinet 
as a furnace, the rated capacity of which is above 225,000 Btu per 
hour, and is a heat pump or a cooling unit only. A central air 
conditioner or central air conditioning heat pump may consist of: A 
single-package unit; an outdoor unit and one or more indoor units; an 
indoor unit only; or an outdoor unit with no match. In the case of an 
indoor unit only or an outdoor unit with no match, the unit must be 
tested and rated as a system (combination of both an indoor and an 
outdoor unit). For all central air conditioner and central air 
conditioning heat pump-related definitions, see appendix M or M1 of 
subpart B of this part.
* * * * *
0
7. Section 430.32 is amended by revising paragraph (c)(6)(ii) to read 
as follows:


Sec.  430.32  Energy and water conservation standards and their 
compliance dates.

* * * * *
    (c) * * *
    (6) * * *
    (ii) Any model of outdoor unit that has a certified combination 
with a rating below the applicable standard level(s) for a region 
cannot be installed in that region. The least-efficient combination of 
each basic model, which for single-split-system AC with single-stage or

[[Page 16858]]

two-stage compressor (including Space-Constrained and Small-Duct High 
Velocity Systems (SDHV)) must be a coil-only combination, must comply 
with the applicable standard. See 10 CFR 429.16(a)(1) and (a)(4)(i) of 
this chapter.
* * * * *
0
8. Appendix M to subpart B of part 430 is amended by:
0
a. Revising the definition of ``Nominal Capacity'' in section 1.2;
0
b. Revising paragraph a of section 3.6.4;
0
c. Revising section 4.1.4.2;
0
d. Revising the introductory text to section 4.2.3;
0
e. Revising the equation following the word ``Where:'' in section 
4.2.3.3; and
0
f. Revising section 4.2.3.4.
    The revisions read as follows:

Appendix M to Subpart B of Part 430--Uniform Test Method for Measuring 
the Energy Consumption of Central Air Conditioners and Heat Pumps

* * * * *
1. * * *
1.2 * * *
    Nominal Cooling Capacity is approximate to the air conditioner 
cooling capacity tested at A or A2 condition. Nominal 
heating capacity is approximate to the heat pump heating capacity 
tested in H1N test.
* * * * *
3. * * *
3.6.4 * * *
    a. Conduct one maximum temperature test (H01), two high 
temperature tests (H1N and H11), one frost 
accumulation test (H2V), and one low temperature test 
(H32). Conducting one or both of the following tests is 
optional: An additional high temperature test (H12) and an 
additional frost accumulation test (H22). If desired, 
conduct the optional maximum temperature cyclic (H0C1) test 
to determine the heating mode cyclic-degradation coefficient, 
CD\h\. If this optional test is conducted but yields a 
tested CD\h\ that exceeds the default CD\h\ or if 
the optional test is not conducted, assign CD\h\ the default 
value of 0.25. Test conditions for the eight tests are specified in 
Table 14. The compressor shall operate at the same heating full speed, 
measured by RPM or power input frequency (Hz), for the H12, 
H22 and H32 tests. For a cooling/heating heat 
pump, the compressor shall operate for the H1N test at a 
speed, measured by RPM or power input frequency (Hz), no lower than the 
speed used in the A2 test if the tested H1N 
heating capacity is less than the tested A2 cooling 
capacity. The compressor shall operate at the same heating minimum 
speed, measured by RPM or power input frequency (Hz), for the 
H01, H1C1, and H11 tests. Determine 
the heating intermediate compressor speed cited in Table 14 using the 
heating mode full and minimum compressors speeds and:

 [GRAPHIC] [TIFF OMITTED] TP24MR22.001

    Where a tolerance on speed of plus 5 percent or the next higher 
inverter frequency step from the calculated value is allowed.
* * * * *

4. * * *

4.1.4.2 Unit Operates at an Intermediate Compressor Speed (k=i) In 
Order To Match the Building Cooling Load at Temperature Tj,Qck=1(Tj) < 
BL(Tj) < Qck=2(Tj).
[GRAPHIC] [TIFF OMITTED] TP24MR22.002

where:

Qck=i(Tj) = BL(Tj), the 
space cooling capacity delivered by the unit in matching the 
building load at temperature Tj, Btu/h. The matching 
occurs with the unit operating at compressor speed k=i.
[GRAPHIC] [TIFF OMITTED] TP24MR22.003

EERk=i(Tj) = the steady-state energy 
efficiency ratio of the test unit when operating at a compressor 
speed of k=i and temperature Tj, Btu/h per W.

    Obtain the fractional bin hours for the cooling season, 
nj/N, from Table 19. For each temperature bin where the unit 
operates at an intermediate compressor speed, determine the energy 
efficiency ratio EERk=i(Tj) using,

EERk=i(Tj) = A + B * Tj + C * Tj2.

    For each unit, determine the coefficients A, B, and C by conducting 
the following calculations once:

A = EERk=2(T2)-(B * T2)-(C * T22)

[[Page 16859]]

[GRAPHIC] [TIFF OMITTED] TP24MR22.004

where:

T1 = the outdoor temperature at which the unit, when 
operating at minimum compressor speed, provides a space cooling 
capacity that is equal to the building load 
(Qck=1(T1) = BL(T1)), 
[deg]F. Determine T1 by equating Equations 4.1.3-1 and 
4.1-2 and solving for outdoor temperature.
Tv = the outdoor temperature at which the unit, when 
operating at the intermediate compressor speed used during the 
section 3.2.4 Ev test of this appendix, provides a space 
cooling capacity that is equal to the building load 
(Qck=v(Tv) = BL(Tv)), 
[deg]F. Determine Tv by equating Equations 4.1.4-3 and 
4.1-2 and solving for outdoor temperature.
T2 = the outdoor temperature at which the unit, when 
operating at full compressor speed, provides a space cooling 
capacity that is equal to the building load 
(Qck=2(T2) = BL(T2)), 
[deg]F. Determine T2 by equating Equations 4.1.3-3 and 
4.1-2 and solving for outdoor temperature.
[GRAPHIC] [TIFF OMITTED] TP24MR22.005

* * * * *

4.2 * * *

4.2.3

Additional Steps for Calculating the HSPF of a Heat Pump Having a Two-
Capacity Compressor

    The calculation of the Equation 4.2-1 quantities differ depending 
upon whether the heat pump would operate at low capacity (section 
4.2.3.1 of this appendix), cycle between low and high capacity (section 
4.2.3.2 of this appendix), or operate at high capacity (sections 
4.2.3.3 and 4.2.3.4 of this appendix) in responding to the building 
load. For heat pumps that lock out low capacity operation at low 
outdoor temperatures, the outdoor temperature at which the unit locks 
out must be that specified by the manufacturer in the certification 
report so that the appropriate equations can be selected.
* * * * *

4.2.3.3 Heat Pump Only Operates at High (k=2) Compressor Capacity at 
Temperature Tj and Its Capacity Is Greater Than the Building Heating 
Load, BL(Tj) < Qhk=2(Tj)

* * * * *
Xk=2(Tj) = BL(Tj)/Qhk=2(Tj); and

PLFj = 1-CDh (k=2) * [1-Xk=2(Tj)].
* * * * *

4.2.3.4 Heat Pump Must Operate Continuously at High (k=2) Compressor 
Capacity at Temperature Tj, BL(Tj) = Qhk=2(Tj)
[GRAPHIC] [TIFF OMITTED] TP24MR22.006

where:

[[Page 16860]]

[GRAPHIC] [TIFF OMITTED] TP24MR22.007

* * * * *
0
9. Appendix M1 to subpart B of part 430 is amended by:
0
a. Adding in alphabetical order definitions for ``Variable-speed 
Communicating Coil-only Central Air Conditioner or Heat Pump'' and 
``Variable-speed Non-communicating Coil-only Central Air Conditioner or 
Heat Pump'' in section 1.2;
0
b. Revising paragraph (B) and the undesignated paragraph following it 
in section 2;
0
c. Revising section 3.1.2;
0
d. Revising paragraphs a. and b. in section 3.1.4.1.1;
0
e. Revising paragraphs a. and b. and adding paragraph f in section 
3.1.4.2:
0
f. Revising paragraph b. and adding paragraph d. in section 3.1.4.3;
0
g. Revising paragraph a. in section 3.1.4.4.3;
0
h. Adding paragraph d. in section 3.1.4.6;
0
i. Revising section 3.1.4.7;
0
j. Revising paragraph a., adding paragraph d., and revising Table 8 in 
section 3.2.4;
0
k. Revising paragraph d., redesignating paragraph e. as paragraph f., 
and adding a new paragraph e. in section 3.3;
0
l. Revising the introductory text, redesignating paragraphs a. and b. 
as c. and d., respectively, adding new paragraphs a. and b., and 
revising newly redesignated paragraph c. in section 3.5.1;
0
m. Revising Table 11 in section 3.6.1;
0
n. Revising Table 12 in section 3.6.2;
0
o. Revising Table 13 in section 3.6.3
0
p. Revising section 3.6.4 and adding sections 3.6.4.1 and 3.6.4.2.;
0
q. Revising Table 15 in section 3.6.6;
0
r. Revising paragraph c., redesignating paragraphs d. and e. as e. and 
f., respectively, and adding new paragraph d. in section 3.7;
0
s. Revising paragraph b. in section 3.8;
0
t. Revising paragraph b. in section 3.9.1;
0
u. Revising section 4.1.4;
0
v. Adding sections 4.1.4.2.1 and 4.1.4.2.2;
0
w. Revising the language after ``Table 20'' and before paragraph a., 
including Equation 4.2-2, in section 4.2;
0
x. Revising the introductory text for section 4.2.3.;
0
y. Revising section 4.2.3.4;
0
z. Revising paragraphs a., b., c., and e., in section 4.2.4;
0
aa. Revising sections 4.2.4.1 and 4.2.4.2; and
0
bb. Removing the language ``and Xk=3(Tj) = 
Xk=2(Tj)'' and adding in its place ``and 
Xk=3(Tj) = 1 - Xk=2(Tj),'' 
in section 4.2.6.5.
    The revisions and additions read as follows:

Appendix M1 to Subpart B of Part 430--Uniform Test Method for Measuring 
the Energy Consumption of Central Air Conditioners and Heat Pumps

* * * * *

1.2 * * *

    Variable-speed Communicating Coil-only Central Air Conditioner 
or Heat Pump means a variable-speed compressor system having a coil-
only indoor unit that is installed with a control system that:
    (a) Communicates the difference in space temperature and space 
setpoint temperature (not a setpoint value inferred from on/off 
thermostat signals) to the control that sets compressor speed;
    (b) Provides a signal to the indoor fan to set fan speed 
appropriate for compressor staging; and
    (c) Has installation instructions indicating that the control 
system having these capabilities must be installed.
* * * * *
    Variable-speed Non-communicating Coil-only Central Air 
Conditioner or Heat Pump means a variable-speed compressor system 
having a coil-only indoor unit that is does not meet the definition 
of variable-speed communicating coil-only central air conditioner or 
heat pump.
* * * * *

2 * * *

    (B) For systems other than VRF, only a subset of the sections 
listed in this test procedure apply when testing and determining 
represented values for a particular unit. Table 1 shows the sections 
of the test procedure that apply to each system. This table is meant 
to assist manufacturers in finding the appropriate sections of the 
test procedure. Manufacturers are responsible for determining which 
sections apply to each unit tested based on the model 
characteristics. The appendix sections provide the specific 
requirements for testing. To use Table 1, first refer to the 
sections listed under ``all units''. Then refer to additional 
requirements based on:
    (1) System configuration(s),
    (2) The compressor staging or modulation capability, and
    (3) Any special features.
    Testing requirements for space-constrained products do not 
differ from similar products that are not space-constrained, and 
thus space-constrained products are not listed separately in this 
table. Air conditioners and heat pumps are not listed separately in 
this table, but heating procedures and calculations apply only to 
heat pumps.
    The ``manufacturer's published instructions,'' as stated in 
section 8.2 of ASHRAE Standard 37-2009 (incorporated by reference, 
see Sec.  430.3) and ``manufacturer's installation instructions'' 
discussed in this appendix mean the manufacturer's installation 
instructions that come packaged with the unit or appear in the 
labels applied to the unit. Manufacturer's installation instructions 
do not include online manuals. Installation instructions that appear 
in the labels applied to the unit shall take precedence over 
installation instructions that come packaged with the unit.
* * * * *

3.1.2 Manufacturer-Provided Equipment Overrides

    Where needed, the manufacturer must provide a means for 
overriding the controls of the test unit so that the compressor(s) 
operates at the specified speed or capacity and the indoor blower 
operates at the specified speed or delivers the specified air volume 
rate. For variable-speed non-communicating coil-only air 
conditioners and heat pumps, the control system shall be provided 
with a control signal indicating operation at high or low stage, 
rather than testing with the compressor speed fixed at specific 
speeds, with the exception that compressor speed override may be 
used for heating mode test H12.
* * * * *

3.1.4.1.1 * * *

    a. For all ducted blower coil systems, except those having a 
constant-air-volume-rate indoor blower:
    Step (1) Operate the unit under conditions specified for the A 
test (for single-stage units) or A2 test (for non-single-
stage units) using the certified fan speed or controls settings, and 
adjust the exhaust fan of the airflow

[[Page 16861]]

measuring apparatus to achieve the certified Cooling full-load air 
volume rate;
    Step (2) Measure the external static pressure;
    Step (3) If this external static pressure is equal to or greater 
than the applicable minimum external static pressure cited in Table 
4, the pressure requirement is satisfied; proceed to step 7 of this 
section. If this external static pressure is not equal to or greater 
than the applicable minimum external static pressure cited in Table 
4, proceed to step 4 of this section;
    Step (4) Increase the external static pressure by adjusting the 
exhaust fan of the airflow measuring apparatus until the first to 
occur of:
    (i) The applicable Table 4 minimum is equaled or
    (ii) The measured air volume rate equals 90 percent or less of 
the Cooling full-load air volume rate;
    Step (5) If the conditions of step 4 (i) of this section occur 
first, the pressure requirement is satisfied; proceed to step 7 of 
this section. If the conditions of step 4 (ii) of this section occur 
first, proceed to step 6 of this section;
    Step (6) Make an incremental change to the setup of the indoor 
blower (e.g., next highest fan motor pin setting, next highest fan 
motor speed) and repeat the evaluation process beginning above, at 
step 1 of this section. If the indoor blower setup cannot be further 
changed, increase the external static pressure by adjusting the 
exhaust fan of the airflow measuring apparatus until the applicable 
Table 4 minimum is equaled; proceed to step 7 of this section;
    Step (7) The airflow constraints have been satisfied. Use the 
measured air volume rate as the Cooling full-load air volume rate. 
Use the final indoor fan speed or control settings of the unit under 
test for all tests that use the Cooling full-load air volume rate. 
Adjust the fan of the airflow measurement apparatus if needed to 
obtain the same full-load air volume rate (in scfm) for all such 
tests, unless the system modulates indoor blower speed with outdoor 
dry bulb temperature or to adjust the sensible to total cooling 
capacity ratio--in this case, use an air volume rate that represents 
a normal installation and calculate the target external static 
pressure as described in section 3.1.4.2 of this appendix.
    b. For ducted blower coil systems with a constant-air-volume-
rate indoor blower. For all tests that specify the Cooling full-load 
air volume rate, obtain an external static pressure as close to (but 
not less than) the applicable Table 4 value that does not cause 
either automatic shutdown of the indoor blower or a value of air 
volume rate variation QVar, defined as follows, that is 
greater than 10 percent.
[GRAPHIC] [TIFF OMITTED] TP24MR22.008

Where:

Qmax = maximum measured airflow value
Qmin = minimum measured airflow value
QVar = airflow variance, percent

    Additional test steps as described in section 3.3.f of this 
appendix are required if the measured external static pressure exceeds 
the target value by more than 0.03 inches of water.
* * * * *

3.1.4.2 * * *

    a. For a ducted blower coil system without a constant-air-volume 
indoor blower, adjust for external static pressure as follows:
    Step (1) Operate the unit under conditions specified for the 
B1 test using the certified fan speed or controls settings, 
and adjust the exhaust fan of the airflow measuring apparatus to 
achieve the certified cooling minimum air volume rate;
    Step (2) Measure the external static pressure;
    Step (3) If this pressure is equal to or greater than the minimum 
external static pressure computed above, the pressure requirement is 
satisfied; proceed to step 7 of this section. If this pressure is not 
equal to or greater than the minimum external static pressure computed 
above, proceed to step 4 of this section;
    Step (4) Increase the external static pressure by adjusting the 
exhaust fan of the airflow measuring apparatus until either:
    (i) The pressure is equal to the minimum external static pressure, 
[Delta]Pst_i, computed above or
    (ii) The measured air volume rate equals 90 percent or less of the 
cooling minimum air volume rate, whichever occurs first;
    Step (5) If the conditions of step 4 (i) of this section occur 
first, the pressure requirement is satisfied; proceed to step 7 of this 
section. If the conditions of step 4 (ii) of this section occur first, 
proceed to step 6 of this section;
    Step (6) Make an incremental change to the setup of the indoor 
blower (e.g., next highest fan motor pin setting, next highest fan 
motor speed) and repeat the evaluation process beginning above, at step 
1 of this section. If the indoor blower setup cannot be further 
changed, increase the external static pressure by adjusting the exhaust 
fan of the airflow measuring apparatus until it equals the minimum 
external static pressure computed above; proceed to step 7 of this 
section;
    Step (7) The airflow constraints have been satisfied. Use the 
measured air volume rate as the cooling minimum air volume rate. Use 
the final indoor fan speed or control settings of the unit under test 
for all tests that use the cooling minimum air volume rate. Adjust the 
fan of the airflow measurement apparatus if needed to obtain the same 
cooling minimum air volume rate (in scfm) for all such tests, unless 
the system modulates the indoor blower speed with outdoor dry bulb 
temperature or to adjust the sensible to total cooling capacity ratio--
in this case, use an air volume rate that represents a normal 
installation and calculate the target minimum external static pressure 
as described in this section 3.1.4.2.
    b. For ducted units with constant-air-volume indoor blowers, 
conduct all tests that specify the cooling minimum air volume rate--
(i.e., the A1, B1, C1, F1, 
and G1 Tests)--at an external static pressure that does not 
cause either an automatic shutdown of the indoor blower or a value of 
air volume rate variation QVar, defined in section 
3.1.4.1.1.b of this appendix, that is greater than 10 percent, while 
being as close to, but not less than the target minimum external static 
pressure. Additional test steps as described in section 3.3.f of this 
appendix are required if the measured external static pressure exceeds 
the target value by more than 0.03 inches of water.
* * * * *
    f. For ducted variable-speed compressor systems tested with a coil-
only indoor unit, the cooling minimum air volume rate is the higher of:
    (1) The rate specified by the installation instructions included 
with the unit by the manufacturer; or
    (2) 75 percent of the cooling full-load air volume rate. During the 
laboratory tests on a coil-only (fanless) system, obtain this cooling 
minimum air volume rate regardless of the pressure drop across the 
indoor coil assembly.
* * * * *

3.1.4.3 * * *

    b. For a ducted blower coil system with a constant-air-volume 
indoor blower, conduct the EV Test at an external static 
pressure that does not cause either an automatic shutdown of the indoor 
blower or a value of air volume rate variation QVar, defined 
in section 3.1.4.1.1.b of this appendix, that is greater than 10 
percent, while being as close to, but not less than the target minimum 
external static pressure. Additional test steps as described in section 
3.3.f of this appendix are required if the measured external static 
pressure exceeds the target value by more than 0.03 inches of water.
* * * * *
    d. For ducted variable-speed compressor systems tested with a coil-
only indoor unit, use the cooling minimum air volume rate as determined 
in section 3.1.4.2(f) of this appendix, without regard to the pressure 
drop across the indoor coil assembly.
* * * * *

[[Page 16862]]

3.1.4.4.3 * * *

    a. For all ducted heating-only blower coil system heat pumps, 
except those having a constant-air-volume-rate indoor blower: Conduct 
the following steps only during the first test, the H1 or 
H12 test:
    Step (1) Adjust the exhaust fan of the airflow measuring apparatus 
to achieve the certified heating full-load air volume rate.
    Step (2) Measure the external static pressure.
    Step (3) If this pressure is equal to or greater than the Table 4 
minimum external static pressure that applies given the heating-only 
heat pump's rated heating capacity, the pressure requirement is 
satisfied; proceed to step 7 of this section. If this pressure is not 
equal to or greater than the applicable Table 4 minimum external static 
pressure, proceed to step 4 of this section;
    Step (4) Increase the external static pressure by adjusting the 
exhaust fan of the airflow measuring apparatus until either:
    (i) The pressure is equal to the applicable Table 4 minimum 
external static pressure; or
    (ii) The measured air volume rate equals 90 percent or less of the 
heating full-load air volume rate, whichever occurs first;
    Step (5) If the conditions of step 4 (i) of this section occur 
first, the pressure requirement is satisfied; proceed to step 7 of this 
section. If the conditions of step 4 (ii) of this section occur first, 
proceed to step 6 of this section;
    Step (6) Make an incremental change to the setup of the indoor 
blower (e.g., next highest fan motor pin setting, next highest fan 
motor speed) and repeat the evaluation process beginning above, at step 
1 of this section. If the indoor blower setup cannot be further 
changed, increase the external static pressure by adjusting the exhaust 
fan of the airflow measuring apparatus until it equals the applicable 
Table 4 minimum external static pressure; proceed to step 7 of this 
section;
    Step (7) The airflow constraints have been satisfied. Use the 
measured air volume rate as the heating full-load air volume rate. Use 
the final indoor fan speed or control settings of the unit under test 
for all tests that use the heating full-load air volume rate. Adjust 
the fan of the airflow measurement apparatus if needed to obtain the 
same heating full-load air volume rate (in scfm) for all such tests, 
unless the system modulates indoor blower speed with outdoor dry bulb 
temperature--in this case, use an air volume rate that represents a 
normal installation and calculate the target minimum external static 
pressure as described in section 3.1.4.2 of this appendix.
* * * * *

3.1.4.6 * * *

    d. For ducted variable-speed compressor systems tested with a coil-
only indoor unit, use the heating minimum air volume rate, which (as 
specified in section 3.1.4.5.1.a.(3) of this appendix) is equal to the 
cooling minimum air volume rate, without regard to the pressure drop 
across the indoor coil assembly.
* * * * *

3.1.4.7 Heating Nominal Air Volume Rate

    The manufacturer must specify the heating nominal air volume rate 
and the instructions for setting fan speed or controls. Calculate 
target minimum external static pressure as described in section 3.1.4.2 
of this appendix. Make adjustments as described in section 3.1.4.6 of 
this appendix for heating intermediate air volume rate so that the 
target minimum external static pressure is met or exceeded. For ducted 
variable-speed compressor systems tested with a coil-only indoor unit, 
use the heating full-load air volume rate as the heating nominal air 
volume rate.
* * * * *

3.2.4 * * *

    a. Conduct five steady-state wet coil tests: The A2, 
EV, B2, B1, and F1 Tests 
(the EV test is not applicable for variable speed non-
communicating coil-only air conditioners and heat pumps). Use the two 
optional dry-coil tests, the steady-state G1 Test and the 
cyclic I1 Test, to determine the cooling mode cyclic 
degradation coefficient, CDc. If the two optional 
tests are conducted and yield a tested CDc that 
exceeds the default CDc or if the two optional 
tests are not conducted, assign CDc the default 
value of 0.25. Table 8 specifies test conditions for these seven tests. 
The compressor shall operate at the same cooling full speed, measured 
by RPM or power input frequency (Hz), for both the A2 and 
B2 tests. The compressor shall operate at the same cooling 
minimum speed, measured by RPM or power input frequency (Hz), for the 
B1, F1, G1, and I1 tests. 
Determine the cooling intermediate compressor speed cited in Table 8, 
as required, using:
[GRAPHIC] [TIFF OMITTED] TP24MR22.009

where a tolerance of plus 5 percent or the next higher inverter 
frequency step from that calculated is allowed.
* * * * *
    d. For variable-speed non-communicating coil-only air conditioners 
and heat pumps, the manufacturer-provided equipment overrides for full 
and minimum compressor speed described in section 3.1.2 of appendix M1 
shall be limited to two stages of digital on/off control.

[[Page 16863]]



                                    Table 8--Cooling Mode Test Condition for Units Having a Variable-Speed Compressor
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                          Air entering indoor unit        Air entering outdoor unit
                                            temperature ([deg]F)            temperature ([deg]F)
           Test description           ----------------------------------------------------------------     Compressor speed      Cooling air volume rate
                                          Dry bulb        Wet bulb        Dry bulb        Wet bulb
--------------------------------------------------------------------------------------------------------------------------------------------------------
A2 Test--required (steady, wet coil).              80              67              95          \1\ 75  Cooling Full............  \2\ Cooling Full-Load.
B2 Test--required (steady, wet coil).              80              67              82          \1\ 65  Cooling Full............  \2\ Cooling Full-Load.
EV Test--required \7\ (steady, wet                 80              67              87          \1\ 69  Cooling Intermediate....  \3\ Cooling
 coil).                                                                                                                           Intermediate.
B1 Test--required (steady, wet coil).              80              67              82           \1\65  Cooling Minimum.........  \4\ Cooling Minimum.
F1 Test--required (steady, wet coil).              80              67              67         \1\53.5  Cooling Minimum.........  \4\ Cooling Minimum.
G1 Test \5\--optional (steady, dry-                80           (\6\)              67  ..............  Cooling Minimum.........  \4\ Cooling Minimum.
 coil).
I1 Test \5\--optional (cyclic, dry-                80           (\6\)              67  ..............  Cooling Minimum.........   (\6\)
 coil).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ The specified test condition only applies if the unit rejects condensate to the outdoor coil.
\2\ Defined in section 3.1.4.1 of this appendix.
\3\ Defined in section 3.1.4.3 of this appendix.
\4\ Defined in section 3.1.4.2 of this appendix.
\5\ The entering air must have a low enough moisture content so no condensate forms on the indoor coil. DOE recommends using an indoor air wet bulb
  temperature of 57 [deg]F or less.
\6\ Maintain the airflow nozzle(s) static pressure difference or velocity pressure during the ON period at the same pressure difference or velocity
  pressure as measured during the G1 Test.
\7\ The EV test is not applicable for variable-speed non-communicating coil-only air conditioners and heat pumps.

* * * * *

3.3 * * *

    d. For mobile home and space-constrained ducted coil-only system 
tests,
    (1) For two-stage or variable-speed systems, for all steady-state 
wet coil tests that specify the cooling minimum air volume rate or 
cooling intermediate air volume rate (i.e., the A1, 
B1, EV, and F1 tests) and for which 
the minimum or intermediate air volume rate is 75 percent of the 
cooling full-load air volume rate:
[GRAPHIC] [TIFF OMITTED] TP24MR22.010

    (2) For two-stage or variable-speed systems, for all steady-state 
wet coil tests that specify the cooling full-load air volume rate 
(i.e., the A2 and B2 tests) or tests using a 
minimum or intermediate air volume rate that is greater than 75 percent 
of the cooling full-load air volume rate:

[[Page 16864]]

[GRAPHIC] [TIFF OMITTED] TP24MR22.011

where VS is the average measured indoor air volume rate 
expressed in units of cubic feet per minute of standard air (scfm).
    e. For non-mobile, non-space-constrained home ducted coil-only 
system tests,
    (1) For two-stage or variable-speed systems, for all steady-state 
wet coil tests that specify the cooling minimum air volume rate or 
cooling intermediate air volume rate (i.e., the A1, 
B1, EV, and F1 tests) and for which 
the minimum or intermediate air volume rate is 75 percent of the 
cooling full-load air volume rate:
[GRAPHIC] [TIFF OMITTED] TP24MR22.012

    (2) For two-stage or variable-speed systems, for all steady-state 
wet coil tests that specify the cooling full-load air volume rate 
(i.e., the A2 and B2 tests) or tests using a 
minimum or intermediate air volume rate that is greater than 75 percent 
of the cooling full-load air volume rate:

[[Page 16865]]

[GRAPHIC] [TIFF OMITTED] TP24MR22.013

where VS is the average measured indoor air volume rate 
expressed in units of cubic feet per minute of standard air (scfm).

  Table 9--Test Operating and Test Condition Tolerances for Section 3.3
    Steady-State Wet Coil Cooling Mode Tests and Section 3.4 Dry Coil
                           Cooling Mode Tests
------------------------------------------------------------------------
                                          Test operating  Test condition
                                           tolerance \1\   tolerance \1\
------------------------------------------------------------------------
Indoor dry-bulb, [deg]F:
    Entering temperature................             2.0             0.5
    Leaving temperature.................             2.0  ..............
Indoor wet-bulb, [deg]F:
    Entering temperature................             1.0         \2\ 0.3
    Leaving temperature.................         \2\ 1.0  ..............
Outdoor dry-bulb, [deg]F:
    Entering temperature................             2.0             0.5
    Leaving temperature.................         \3\ 2.0  ..............
Outdoor wet-bulb, [deg]F:
    Entering temperature................             1.0         \4\ 0.3
    Leaving temperature.................         \3\ 1.0  ..............
External resistance to airflow, inches              0.05        \5\ 0.02
 of water...............................
Electrical voltage, % of reading........             2.0             1.5
Nozzle pressure drop, % of reading......             2.0  ..............
------------------------------------------------------------------------
\1\ See section 1.2 of this appendix, Definitions.
\2\ Only applies during wet coil tests; does not apply during steady-
  state, dry coil cooling mode tests.
\3\ Only applies when using the outdoor air enthalpy method.
\4\ Only applies during wet coil cooling mode tests where the unit
  rejects condensate to the outdoor coil.
\5\ Only applies when testing non-ducted units.

* * * * *

3.5.1 * * *

    The automatic controls that are installed in the test unit must 
govern the OFF/ON cycling of the air moving equipment on the indoor 
side (i.e. the exhaust fan of the airflow measuring apparatus and the 
indoor blower of the test unit). For ducted coil-only systems rated 
based on using a fan time-delay relay, control the indoor coil airflow 
according to the OFF delay listed by the manufacturer in the 
certification report. For ducted units having a variable-speed indoor 
blower that has been disabled (and possibly removed), start and stop 
the indoor airflow at the same instances as if the fan were enabled. 
For all other ducted coil-only systems, cycle the indoor coil airflow 
in unison with the cycling of the compressor. If air damper boxes are 
used, close them on the inlet and outlet side during the OFF period. 
Airflow through the indoor coil should stop within 3 seconds after the 
automatic controls of the test unit de-energize (or if the airflow 
system has been disabled (and possibly removed), within 3 seconds after 
the automatic controls of the test unit would have de-energized) the 
indoor blower.
    a. For mobile home and space-constrained ducted coil-only systems,
    (1) For two-stage or variable-speed systems, for all cyclic dry-
coil tests that specify the cooling minimum air volume rate (i.e., the 
D1 and I1 tests) and for which the minimum air 
volume rate is 75 percent of the cooling full-load air volume rate, 
increase ecyc,dry by the quantity,

[[Page 16866]]

[GRAPHIC] [TIFF OMITTED] TP24MR22.014

where VS is the average indoor air volume rate from the 
section 3.4 dry coil steady-state test and is expressed in units of 
cubic feet per minute of standard air (scfm).

    (2) For two-stage or variable-speed systems, for all cyclic dry-
coil tests that specify the cooling full-load air volume rate (i.e., 
the D2 test) or tests using a minimum air volume rate that 
is greater than 75 percent of the cooling full-load air volume rate 
increase ecyc,dry by the quantity,
[GRAPHIC] [TIFF OMITTED] TP24MR22.015

    (3) For single-stage systems, for all cyclic dry-coil tests (i.e., 
the D test) increase ecyc,dry by the quantity calculated in 
Equation 3.5-4 and decrease qcyc,dry by the quantity 
calculated in Equation 3.5-5
    b. For ducted, non-mobile, non-space-constrained home coil-only 
units,
    (1) For two-stage or variable-speed systems, for all cyclic dry-
coil tests that specify the cooling minimum air volume rate (i.e., the 
D1 and I1 tests) and for which the minimum air 
volume rate is 75 percent of the cooling full-load air volume rate, 
increase ecyc,dry by the quantity,
[GRAPHIC] [TIFF OMITTED] TP24MR22.016

    (2) For two-stage or variable-speed systems, for all cyclic dry-
coil tests that specify the cooling full-load air volume rate (i.e., 
the D2 test) or tests using a minimum air volume rate that 
is greater than 75 percent of the cooling full-load air volume rate 
increase ecyc,dry by the quantity,

[[Page 16867]]

[GRAPHIC] [TIFF OMITTED] TP24MR22.017

    (3) For single-stage systems, for all cyclic dry-coil tests (i.e., 
the D test) increase ecyc,dry by the quantity calculated in 
Equation 3.5-8 and decrease qcyc,dry by the quantity 
calculated in Equation 3.5-9
    c. For units having a variable-speed indoor blower that is disabled 
during the cyclic test, increase ecyc,dry and decrease 
qcyc,dry based on: The product of [[tau]2-
[tau]1] and the indoor blower power (in W) measured during 
or following the dry coil steady-state test; or,
* * * * *

3.6 * * *

3.6.1 Tests for a Heat Pump Having a Single-Speed Compressor and Fixed 
Heating Air Volume Rate

* * * * *

   Table 11--Heating Mode Test Conditions for Units Having a Single-Speed Compressor and a Fixed-Speed Indoor
                         Blower, a Constant Air Volume Rate Indoor Blower, or Coil-Only
----------------------------------------------------------------------------------------------------------------
                                   Air entering indoor unit        Air entering outdoor unit
                                     temperature ([deg]F)             temperature ([deg]F)         Heating air
       Test description       ------------------------------------------------------------------   volume rate
                                  Dry bulb         Wet bulb        Dry bulb         Wet bulb
----------------------------------------------------------------------------------------------------------------
H1 test (required, steady)...              70  60 (max).......              47  43.............  Heating Full-
                                                                                                  Load.\1\
H1C test (optional, cyclic)..              70  60 (max).......              47  43.............  (\2\)
H2 test (required)...........              70  60 (max).......              35  33.............  Heating Full-
                                                                                                  Load.\1\
H3 test (required, steady)...              70  60 (max).......              17  15.............  Heating Full-
                                                                                                  Load.\1\
H4 test (optional, steady)...              70  60 (max).......               5  4 (max)........  Heating Full-
                                                                                                  Load.\1\
----------------------------------------------------------------------------------------------------------------
\1\ Defined in section 3.1.4.4 of this appendix.
\2\ Maintain the airflow nozzle(s) static pressure difference or velocity pressure during an ON period at the
  same pressure or velocity as measured during the H1 test.

* * * * *

3.6.2 Tests for a Heat Pump Having a Single-Speed Compressor and a 
Single Indoor Unit Having Either (1) a Variable-Speed, Variable-Air-
Rate Indoor Blower Whose Capacity Modulation Correlates With Outdoor 
Dry Bulb Temperature or (2) Multiple Indoor Blowers

* * * * *

   Table 12--Heating Mode Test Conditions for Units With a Single-Speed Compressor That Meet the Section 3.6.2
                                            Indoor Unit Requirements
----------------------------------------------------------------------------------------------------------------
                                   Air entering indoor unit        Air entering outdoor unit
                                     temperature ([deg]F)             temperature ([deg]F)         Heating air
       Test description       ------------------------------------------------------------------   volume rate
                                  Dry bulb         Wet bulb        Dry bulb         Wet bulb
----------------------------------------------------------------------------------------------------------------
H12 test (required, steady)..              70  60 (max).......              47  43.............  Heating Full-
                                                                                                  Load.\1\
H11 test (required, steady)..              70  60 (max).......              47  43.............  Heating
                                                                                                  Minimum.\2\
H1C1 test (optional, cyclic).              70  60 (max).......              47  43.............  (\3\)
H22 test (required)..........              70  60 (max).......              35  33.............  Heating Full-
                                                                                                  Load.\1\
H21 test (optional)..........              70  60 (max).......              35  33.............  Heating
                                                                                                  Minimum.\2\
H32 test (required, steady)..              70  60 (max).......              17  15.............  Heating Full-
                                                                                                  Load.\1\
H31 test (required, steady)..              70  60 (max).......              17  15.............  Heating
                                                                                                  Minimum\2\
H42 test (optional, steady)..              70  60 (max).......               5  4 (max)........  Heating Full-
                                                                                                  Load.\1\
----------------------------------------------------------------------------------------------------------------
\1\ Defined in section 3.1.4.4 of this appendix.
\2\ Defined in section 3.1.4.5 of this appendix.

[[Page 16868]]

 
\3\ Maintain the airflow nozzle(s) static pressure difference or velocity pressure during an ON period at the
  same pressure or velocity as measured during the H11 test.

* * * * *

3.6.3 Tests for a Heat Pump Having a Two-Capacity Compressor (see 
Section 1.2 of This Appendix, Definitions), Including Two-Capacity, 
Northern Heat Pumps (see Section 1.2 of This Appendix, Definitions)

* * * * *

                                    Table 13--Heating Mode Test Conditions for Units Having a Two-Capacity Compressor
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                   Air entering indoor unit temperature        Air entering outdoor unit
                                                 ([deg]F)                        temperature ([deg]F)                                 Heating air volume
         Test description         ----------------------------------------------------------------------------  Compressor capacity          rate
                                      Dry bulb           Wet bulb           Dry bulb           Wet bulb
--------------------------------------------------------------------------------------------------------------------------------------------------------
H01 test (required, steady)......              70  60 (max)............              62  56.5................  Low.................  Heating Minimum.\1\
H12 test (required, steady)......              70  60 (max)............              47  43..................  High................  Heating Full-
                                                                                                                                      Load.\2\
H1C2 test (optional,\7\ cyclic)..              70  60 (max)............              47  43..................  High................  (\3\)
H11 test (required, steady)......              70  60 (max)............              47  43..................  Low.................  Heating Minimum.\1\
H1C1 test (optional, cyclic).....              70  60 (max)............              47  43..................  Low.................  (\4\)
H22 test (required)..............              70  60 (max)............              35  33..................  High................  Heating Full-
                                                                                                                                      Load.\2\
H21 test\5,6\ (required).........              70  60 (max)............              35  33..................  Low.................  Heating Minimum.\1\
H32 test (required, steady)......              70  60 (max)............              17  15..................  High................  Heating Full-
                                                                                                                                      Load.\2\
H31 test\5\ (required, steady)...              70  60 (max)............              17  15..................  Low.................  Heating Minimum.\1\
H42 test (optional, steady)......              70  60 (max)............               5  4 (max).............  High................  Heating Full-
                                                                                                                                      Load.\2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Defined in section 3.1.4.5 of this appendix.
\2\ Defined in section 3.1.4.4 of this appendix.
\3\ Maintain the airflow nozzle(s) static pressure difference or velocity pressure during an ON period at the same pressure or velocity as measured
  during the H12 test.
\4\ Maintain the airflow nozzle(s) static pressure difference or velocity pressure during an ON period at the same pressure or velocity as measured
  during the H11 test.
\5\ Required only if the heat pump's performance when operating at low compressor capacity and outdoor temperatures less than 37 [deg]F is needed to
  complete the section 4.2.3 HSPF2 calculations.
\6\ If table note #5 applies, the section 3.6.3 equations for Q hk=1 (35) and E hk=1 (17) may be used in lieu of conducting the H21 test.
\7\ Required only if the heat pump locks out low-capacity operation at lower outdoor temperatures.

* * * * *

3.6.4 Tests for a Heat Pump Having a Variable-Speed Compressor

3.6.4.1. Variable-Speed Compressor Other Than Non-communicating Coil-
Only Heat Pumps

    a. Conduct one maximum temperature test (H01), two high 
temperature tests (H1N and H11), one frost 
accumulation test (H2V), and one low temperature test 
(H32). Conducting one or more of the following tests is 
optional: an additional high temperature test (H12), an 
additional frost accumulation test (H22), and a very low 
temperature test (H42). Conduct the optional high 
temperature cyclic (H1C1) test to determine the heating mode 
cyclic-degradation coefficient, CDh. If this 
optional test is conducted and yields a tested 
CDh that exceeds the default 
CDh or if the optional test is not conducted, 
assign CD\h\ the default value of 0.25. Test conditions for 
the nine tests are specified in Table 14A. The compressor shall operate 
for the H12, H22 and H32 Tests at the 
same heating full speed, measured by RPM or power input frequency (Hz), 
as the maximum speed at which the system controls would operate the 
compressor in normal operation in 17 [deg]F ambient temperature. The 
compressor shall operate for the H1N test at the maximum 
speed at which the system controls would operate the compressor in 
normal operation in 47 [deg]F ambient temperature. Additionally, for a 
cooling/heating heat pump, the compressor shall operate for the 
H1N test at a speed, measured by RPM or power input 
frequency (Hz), no lower than the speed used in the A2 test 
if the tested H1N heating capacity is less than the tested 
A2 cooling capacity. The compressor shall operate at the 
same heating minimum speed, measured by RPM or power input frequency 
(Hz), for the H01, H1C1, and H11 
Tests. Determine the heating intermediate compressor speed cited in 
Table 14A using the heating mode full and minimum compressors speeds 
and:

[[Page 16869]]

[GRAPHIC] [TIFF OMITTED] TP24MR22.018

where a tolerance of plus 5 percent or the next higher inverter 
frequency step from that calculated is allowed.
    b. If one of the high temperature tests (H12 or 
H1N) is conducted using the same compressor speed (RPM or 
power input frequency) as the H32 test, set the 47 [deg]F 
capacity and power input values used for calculation of HSPF2 equal to 
the measured values for that test:
[GRAPHIC] [TIFF OMITTED] TP24MR22.019

    Qhk=2(47) is the capacity measured in the 
high temperature test (H12 or H1N) that used the 
same compressor speed as the H32 test, and
    Ehk=2(47) is the power input measured in the 
high temperature test (H12 or H1N) which used the 
same compressor speed as the H32 test.
    Evaluate the quantities Qhk=2(47) and 
Ehk=2(47) according to section 3.7 of this 
appendix.
    Otherwise (if no high temperature test is conducted using the same 
speed (RPM or power input frequency) as the H32 test), 
calculate the 47 [deg]F capacity and power input values used for 
calculation of HSPF2 as follows:
[GRAPHIC] [TIFF OMITTED] TP24MR22.020

Qhk=2(17) is the capacity measured in the 
H32 test,
Ehk=2(17) is the power input measured in the 
H32 test,
CSF is the capacity slope factor, equal to 0.0204/[deg]F for split 
systems and 0.0262/[deg]F for single-package systems, and
PSF is the Power Slope Factor, equal to 0.00455/[deg]F.

    c. If the H22 test is not done, use the following 
equations to approximate the capacity and electrical power at the 
H22 test conditions:

[[Page 16870]]

[GRAPHIC] [TIFF OMITTED] TP24MR22.021

    Qhk=2(17) and Ehk=2(17) 
and are the capacity and power input measured in the H32 
test.
    d. Determine the quantities Qhk=2(17) and 
Ehk=2(17) from the H32 test, determine 
the quantities Qhk=2(5) and 
Ehk=2(5) from the H42 test, and 
evaluate all four according to section 3.10 of this appendix.
    e. For multiple-split heat pumps (only), the following procedures 
supersede the above requirements. For all Table 14A tests specified for 
a minimum compressor speed, turn off at least one indoor unit. The 
manufacturer shall designate the particular indoor unit(s) to be turned 
off. The manufacturer must also specify the compressor speed used for 
the Table 14A H2V test, a heating mode intermediate 
compressor speed that falls within \1/4\ and \3/4\ of the difference 
between the full and minimum heating mode speeds. The manufacturer 
should prescribe an intermediate speed that is expected to yield the 
highest COP for the given H2V test conditions and bracketed 
compressor speed range. The manufacturer can designate that one or more 
specific indoor units are turned off for the H2V test.

  Table 14A--Heating Mode Test Conditions for Units Having a Variable-Speed Compressor Other Than Variable-speed Non-communicating Coil-Only Heat Pumps
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                   Air entering indoor unit temperature        Air entering outdoor unit
                                                 ([deg]F)                        temperature ([deg]F)                                 Heating air volume
         Test description         ----------------------------------------------------------------------------   Compressor speed            rate
                                      Dry bulb           Wet bulb           Dry bulb           Wet bulb
--------------------------------------------------------------------------------------------------------------------------------------------------------
H01 test (required, steady)......              70  60 (max)............              62  56.5................  Heating Minimum.....  Heating Minimum.\1\
H12 test (optional, steady)......              70  60 (max)............              47  43..................  Heating Full \4\....  Heating Full-
                                                                                                                                      Load.\3\
H11 test (required, steady)......              70  60 (max)............              47  43..................  Heating Minimum.....  Heating Minimum.\1\
H1N test (required, steady)......              70  60 (max)............              47  43..................  Heating Full \5\....  Heating Nominal\7\
H1C1 test (optional, cyclic).....              70  60 (max)............              47  43..................  Heating Minimum.....  (\2\)
H22 test (optional)..............              70  60 (max)............              35  33..................  Heating Full \4\....  Heating Full-
                                                                                                                                      Load.\3\
H2V test (required)..............              70  60 (max)............              35  33..................  Heating Intermediate  Heating
                                                                                                                                      Intermediate.\6\
H32 test (required, steady)......              70  60 (max)............              17  15..................  Heating Full \4\....  Heating Full-
                                                                                                                                      Load.\3\
H42 test (optional, steady)......              70  60 (max)............               5  4 (max).............  Heating Full \8\....  Heating Full-
                                                                                                                                      Load.\3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Defined in section 3.1.4.5 of this appendix.
\2\ Maintain the airflow nozzle(s) static pressure difference or velocity pressure during an ON period at the same pressure or velocity as measured
  during the H11 test.
\3\ Defined in section 3.1.4.4 of this appendix.
\4\ Maximum speed that the system controls would operate the compressor in normal operation in 17 [deg]F ambient temperature. The H12 test is not needed
  if the H1N test uses this same compressor speed.
\5\ Maximum speed that the system controls would operate the compressor in normal operation in 47 [deg]F ambient temperature.
\6\ Defined in section 3.1.4.6 of this appendix.
\7\ Defined in section 3.1.4.7 of this appendix.
\8\ Maximum speed that the system controls would operate the compressor in normal operation at 5 [deg]F ambient temperature.

3.6.4.2. Variable-Speed Compressor With Non-communicating Coil-Only 
Heat Pumps

    a. Conduct one maximum temperature test (H01), two high 
temperature tests (H1N and H11), two frost 
accumulation test (H22 and H21), and two low 
temperature tests (H32 and H31). Conducting one 
or both of the following tests is optional: An additional high 
temperature test (H12) and a very low temperature test 
(H42). Conduct the optional high temperature cyclic 
(H1C1) test to determine the heating mode cyclic-degradation 
coefficient, CDh. If this optional test is 
conducted and yields a tested CDh that exceeds 
the default CDh or if the optional test is not 
conducted, assign CDh the default value of 0.25. 
Test conditions for the ten tests are specified in Table 14B. The 
compressor shall operate for the H12 and H32 
tests at the same heating full speed, measured by RPM or power input 
frequency (Hz), as the maximum speed at which the system controls would 
operate the compressor in normal operation in 17 [deg]F ambient 
temperature. The compressor shall operate for the H1N test 
at the maximum speed at which the system controls would operate the 
compressor in normal operation in 47 [deg]F ambient temperature. 
Additionally, for a cooling/heating heat pump, the compressor shall 
operate for the H1N test at a speed, measured by RPM or 
power input frequency (Hz), no lower than the speed used in the 
A2 test if the tested H1N heating capacity is 
less than the tested A2 cooling capacity. The compressor 
shall operate at the same heating minimum speed, measured by RPM or 
power input frequency (Hz), for the H01, H1C1, 
and H11 tests.
    b. If one of the high temperature tests (H12 or 
H1N) is conducted using the same compressor speed (RPM or 
power

[[Page 16871]]

input frequency) as the H32 test, set the 47 [deg]F capacity 
and power input values used for calculation of HSPF2 equal to the 
measured values for that test:
[GRAPHIC] [TIFF OMITTED] TP24MR22.022

    Qhk=2(47) is the capacity measured in the 
high temperature test (H12 or H1N) which used the 
same compressor speed as the H32 test, and
    Ehk=2(47) is the power input measured in the 
high temperature test (H12 or H1N) which used the 
same compressor speed as the H32 test.
    Evaluate the quantities Qhk=2(47) and 
Ehk=2(47) according to section 3.7 of this 
appendix.
    Otherwise (if no high temperature test is conducted using the same 
speed (RPM or power input frequency) as the H32 test), 
calculate the 47 [deg]F capacity and power input values used for 
calculation of HSPF2 as follows:
[GRAPHIC] [TIFF OMITTED] TP24MR22.023

    Qhk=2(17) is the capacity measured in the 
H32 test,
    Ehk=2(17) is the power input measured in the 
H32 test,
CSF is the capacity slope factor, equal to 0.0204/[deg]F for split 
systems, and
PSF is the Power Slope Factor, equal to 0.00455/[deg]F.

    c. Determine the quantities Qhk=2(17) and 
Ehk=2(17) from the H32 test, determine 
the quantities Qhk=2(5) and 
Ehk=2(5) from the H42 test, and 
evaluate all four according to section 3.10 of this appendix.

                            Table 14B--Heating Mode Test Conditions for Variable-Speed Non-communicating Coil-Only Heat Pumps
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                   Air entering indoor unit temperature        Air entering outdoor unit
                                                 ([deg]F)                        temperature ([deg]F)                                 Heating air volume
         Test description         ----------------------------------------------------------------------------   Compressor speed            rate
                                      Dry bulb           Wet bulb           Dry bulb           Wet bulb
--------------------------------------------------------------------------------------------------------------------------------------------------------
H01 test (required, steady)......              70  60 (max)............              62  56.5................  Heating Minimum.....  Heating Minimum.\1\
H12 test (optional, steady)......              70  60 (max)............              47  43..................  Heating Full \4\....  Heating Full-
                                                                                                                                      Load.\3\
H11 test (required, steady)......              70  60 (max)............              47  43..................  Heating Minimum.....  Heating Minimum.\1\
H1N test (required, steady)......              70  60 (max)............              47  43..................  Heating Full \5\....  Heating Full-
                                                                                                                                      Load.\3\
H1C1 test (optional, cyclic).....              70  60 (max)............              47  43..................  Heating Minimum.....  (\2\)
H22 test (required)..............              70  60 (max)............              35  33..................  Heating Full \6\....  Heating Full-
                                                                                                                                      Load.\3\
H21 test (required)..............              70  60 (max)............              35  33..................  Heating Minimum \7\.  Heating Minimum.\1\
H32 test (required, steady)......              70  60 (max)............              17  15..................  Heating Full \4\....  Heating Full-
                                                                                                                                      Load.\3\

[[Page 16872]]

 
H31 test (required, steady)......              70  60 (max)............              17  15..................  Heating Minimum \8\.  Heating Minimum.\1\
H42 test (optional, steady)......              70  60 (max)............               5  4 (max).............  Heating Full \9\....  Heating Full-
                                                                                                                                      Load.\3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Defined in section 3.1.4.5 of this appendix.
\2\ Maintain the airflow nozzle(s) static pressure difference or velocity pressure during an ON period at the same pressure or velocity as measured
  during the H11 test.
\3\ Defined in section 3.1.4.4 of this appendix.
\4\ Maximum speed that the system controls would operate the compressor in normal operation in 17 [deg]F ambient temperature. The H12 test is not needed
  if the H1N test uses this same compressor speed.
\5\ Maximum speed that the system controls would operate the compressor in normal operation in 47 [deg]F ambient temperature.
\6\ Maximum speed that the system controls would operate the compressor in normal operation in 35 [deg]F ambient temperature.
\7\ Minimum speed that the system controls would operate the compressor in normal operation in 35 [deg]F ambient temperature.
\8\ Minimum speed that the system controls would operate the compressor in normal operation in 17 [deg]F ambient temperature.
\9\ Maximum speed that the system controls would operate the compressor in normal operation in 5 [deg]F ambient temperature.

* * * * *

3.6.6. Heating Mode Tests for Northern Heat Pumps with Triple-Capacity 
Compressors

* * * * *

                                   Table 15--Heating Mode Test Conditions for Units With a Triple-Capacity Compressor
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                     Air entering indoor unit ([deg]F)    Air entering outdoor unit ([deg]F)
         Test description         ----------------------------------------------------------------------------  Compressor capacity   Heating air volume
                                      Dry bulb           Wet bulb           Dry bulb           Wet bulb                                      rate
--------------------------------------------------------------------------------------------------------------------------------------------------------
H01 Test (required, steady)......              70  60 (max)............              62  56.5................  Low.................  Heating Minimum.\1\
H12 (required, steady)...........              70  60 (max)............              47  43..................  High................  Heating Full-
                                                                                                                                      Load.\2\
H1C2 Test (optional,\8\ cyclic...              70  60 (max)............              47  43..................  High................  (\3\)
H11 Test (required, steady)......              70  60 (max)............              47  43..................  Low.................  Heating Minimum.\1\
H1C1 Test (optional, cyclic).....              70  60 (max)............              47  43..................  Low.................  (\4\)
H23 Test (optional, steady)......              70  60 (max)............              35  33..................  Booster.............  Heating Full-
                                                                                                                                      Load.\2\
H22 Test (required)..............              70  60 (max)............              35  33..................  High................  Heating Full-
                                                                                                                                      Load.\2\
H21 Test (required)..............              70  60 (max)............              35  33..................  Low.................  Heating Minimum.\1\
H33 Test (required, steady)......              70  60 (max)............              17  15..................  Booster.............  Heating Full-
                                                                                                                                      Load.\2\
H3C3 Test 5 6 (optional, cyclic).              70  60 (max)............              17  15..................  Booster.............  (\7\)
H32 Test (required, steady)......              70  60 (max)............              17  15..................  High................  Heating Full-
                                                                                                                                      Load.\2\
H31 Test \5\ (required, steady)..              70  60 (max)............              17  15..................  Low.................  Heating Minimum.\1\
H43 Test (required, steady)......              70  60 (max)............               5  4 (max).............  Booster.............  Heating Full-
                                                                                                                                      Load.\2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Defined in section 3.1.4.5 of this appendix.
\2\ Defined in section 3.1.4.4 of this appendix.
\3\ Maintain the airflow nozzle(s) static pressure difference or velocity pressure during the ON period at the same pressure or velocity as measured
  during the H12 test.
\4\ Maintain the airflow nozzle(s) static pressure difference or velocity pressure during the ON period at the same pressure or velocity as measured
  during the H11 test.
\5\ Required only if the heat pump's performance when operating at low compressor capacity and outdoor temperatures less than 37 [deg]F is needed to
  complete the section 4.2.6 HSPF2 calculations.
\6\ If table note \5\ applies, the section 3.6.6 equations for Qhk=1(35) and Ehk=1(17) may be used in lieu of conducting the H21 test.
\7\ Maintain the airflow nozzle(s) static pressure difference or velocity pressure during the ON period at the same pressure or velocity as measured
  during the H33 test.
\8\ Required only if the heat pump locks out low-capacity operation at lower outdoor temperatures

* * * * *

3.7 * * *

    c. For mobile home and space-constrained ducted coil-only system 
tests,
    (1) For two-stage or variable-speed systems, for all steady-state 
maximum temperature and high temperature tests that specify the heating 
minimum air volume rate or the heating intermediate air volume rate 
(i.e., the H01 and H11 tests) and for which the 
minimum or intermediate air volume rate is 75 percent of the cooling 
full-load air volume rate:
[GRAPHIC] [TIFF OMITTED] TP24MR22.024


[[Page 16873]]


    (2) For two-stage or variable-speed systems, for all steady-state 
maximum temperature and high temperature tests that specify the heating 
full-load air volume rate or the heating nominal air volume rate (i.e., 
the H12 and the H1N tests) or tests using a 
minimum or intermediate air volume rate that is greater than 75 percent 
of the cooling full-load air volume rate:
[GRAPHIC] [TIFF OMITTED] TP24MR22.025

    (3) For single-stage systems, for all steady-state maximum 
temperature and high temperature tests (i.e., the H1 test)--
[GRAPHIC] [TIFF OMITTED] TP24MR22.026

Where VS is the average measured indoor air volume rate 
expressed in units of cubic feet per minute of standard air (scfm).
    d. For non-mobile, non-space-constrained home ducted coil-only 
system tests,
    (1) For two-stage or variable-speed systems, for all steady-state 
maximum temperature and high temperature tests that specify the heating 
minimum air volume rate or the heating intermediate air volume rate 
(i.e., the H01 and H11 tests) and for which the 
minimum or intermediate air volume rate is 75 percent of the cooling 
full-load air volume rate:
[GRAPHIC] [TIFF OMITTED] TP24MR22.027

    (2) For two-stage or variable-speed systems, for all steady-state 
maximum temperature and high temperature tests that specify the heating 
full-load air volume rate or the heating nominal air volume rate (i.e., 
the H12 and the H1N tests) or tests using a 
minimum or intermediate air volume rate that is greater than 75 percent 
of the cooling full-load air volume rate:

[[Page 16874]]

[GRAPHIC] [TIFF OMITTED] TP24MR22.028

where VS is the average measured indoor air volume rate 
expressed in units of cubic feet per minute of standard air (scfm).
* * * * *

3.8 * * *

    b. For ducted coil-only system heat pumps (excluding the special 
case where a variable-speed fan is temporarily removed),
    (1) For mobile home and space-constrained ducted coil-only systems
    (i) For two-stage or variable-speed systems, for all cyclic heating 
tests that specify the heating minimum air volume rate (i.e., the 
H1C1 test), increase qcyc by the amount 
calculated using Equation 3.5-3. Additionally, increase ecyc 
by the amount calculated using Equation 3.5-2.
    (ii) For two-stage or variable-speed systems, for all cyclic 
heating tests that specify the heating full-load air volume rate (i.e., 
the H1C2 test), increase qcyc by the amount 
calculated using Equation 3.5-5. Additionally, increase ecyc 
by the amount calculated using Equation 3.5-4.
    (iii) For single-stage systems, for all cyclic heating tests (i.e., 
the H1C and H1C1 tests), increase qcyc by the 
amount calculated using Equation 3.5-5. Additionally, increase 
ecyc by the amount calculated using Equation 3.5-4.
    (2) For non-mobile home and non-space-constrained ducted coil-only 
systems
    (i) For two-stage or variable-speed systems, for all cyclic heating 
tests that specify the heating minimum air volume rate (i.e., the 
H1C1 test)--increase qcyc by the amount 
calculated using Equation 3.5-7. Additionally, increase ecyc 
by the amount calculated using Equation 3.5-6.
    (ii) For two-stage or variable-speed systems, for all cyclic 
heating tests that specify the heating full-load air volume rate (i.e., 
the H1C2 test)--increase qcyc by the amount 
calculated using Equation 3.5-9. Additionally, increase ecyc 
by the amount calculated using Equation 3.5-8.
    (iii) For single-stage systems, for all cyclic heating tests (i.e., 
the H1C and H1C1 tests)--increase qcyc by the 
amount calculated using Equation 3.5-9. Additionally, increase 
ecyc by the amount calculated using Equation 3.5-8.
    In making these calculations, use the average indoor air volume 
rate (VS) determined from the section 3.7 of this appendix 
steady-state heating mode test conducted at the same test conditions.
* * * * *

3.9.1 * * *
[GRAPHIC] [TIFF OMITTED] TP24MR22.029

    (1) For mobile home and space-constrained ducted coil-only system 
tests,
    (i) For two-stage or variable-speed systems, for all frost 
accumulation tests that specify the heating minimum air volume rate or 
the heating intermediate air volume rate (i.e., the H21 and 
H2V tests) and for which the minimum or intermediate air 
volume rate is 75 percent of the cooling full-load air volume rate,

[[Page 16875]]

[GRAPHIC] [TIFF OMITTED] TP24MR22.030

    (ii) For two-stage and variable-speed systems, for all frost 
accumulation tests that specify the heating full-load air volume rate 
or the heating nominal air volume rate (i.e., the H22 test) 
or tests using a minimum or intermediate air volume rate that is 
greater than 75 percent of the cooling full-load air volume rate:
[GRAPHIC] [TIFF OMITTED] TP24MR22.031

where VS is the average measured indoor air volume rate 
expressed in units of cubic feet per minute of standard air (scfm).
    (2) For non-mobile home and non-space-constrained ducted coil-only 
systems,
    (i) For two-stage or variable-speed systems, for all frost 
accumulation tests that specify the heating minimum air volume rate or 
the heating intermediate air volume rate (i.e., the H21 and H2V tests) 
and for which the minimum or intermediate air volume rate is 75 percent 
of the cooling full-load air volume rate,
[GRAPHIC] [TIFF OMITTED] TP24MR22.032

    (ii) For two-stage and variable-speed systems, for all frost 
accumulation tests that specify the heating full-load air volume rate 
or the heating nominal air volume rate (i.e., the H22 test) or tests 
using a minimum or intermediate air volume rate that is greater than 75 
percent of the cooling full-load air volume rate:

[[Page 16876]]

[GRAPHIC] [TIFF OMITTED] TP24MR22.033

where VS is the average measured indoor air volume rate 
expressed in units of cubic feet per minute of standard air (scfm).
* * * * *

4.1.4 SEER2 Calculations for an Air Conditioner or Heat Pump Having a 
Variable-Speed Compressor

    Calculate SEER2 using Equation 4.1-1. Evaluate the space cooling 
capacity, Qck=1(Tj), and electrical 
power consumption, Eck=1(Tj), of the 
test unit when operating at minimum compressor speed and outdoor 
temperature Tj.. Use,
[GRAPHIC] [TIFF OMITTED] TP24MR22.034

where Qck=1(82) and 
Eck=1(82) are determined from the B1 
test, Qck=1(67) and 
Eck=1(67) are determined from the F1 test, and 
all four quantities are calculated as specified in section 3.3 of this 
appendix. Evaluate the space cooling capacity, 
Qck=2(Tj), and electrical power 
consumption, Eck=2(Tj), of the test 
unit when operating at full compressor speed and outdoor temperature 
Tj. Use Equations 4.1.3-3 and 4.1.3-4, respectively, where 
Qck=2(95) and Eck=2(95) are 
determined from the A2 test, Qck=2(82) 
and Ec\k=2\(82) are determined from the B2 test, 
and all four quantities are calculated as specified in section 3.3 of 
this appendix. For units other than variable-speed non-communicating 
coil-only air-conditioners or heat pumps, calculate the space cooling 
capacity, Qck=v(Tj), and electrical 
power consumption, Eck=v(Tj), of the 
test unit when operating at outdoor temperature Tj and the 
intermediate compressor speed used during the section 3.2.4 (and Table 
8) EV test of this appendix using,
[GRAPHIC] [TIFF OMITTED] TP24MR22.035

where Qck=v(87) and 
Eck=v(87) are determined from the EV 
test and calculated as specified in section 3.3 of this appendix. 
Approximate the slopes of the k=v intermediate speed cooling capacity 
and electrical power input curves, MQ and ME, as 
follows:

[[Page 16877]]

[GRAPHIC] [TIFF OMITTED] TP24MR22.036

    Use Equations 4.1.4-1 and 4.1.4-2, respectively, to calculate 
Qck=1(87) and Eck=1(87).
* * * * *

4.1.4.2.1 Units That Are Not Variable-Speed Non-Communicating Coil-Only 
Air Conditioners or Heat Pumps

    If the unit operates at an intermediate compressor speed (k=i) in 
order to match the building cooling load at temperature Tj, 
Qck=1(Tj) < BL(Tj) < 
Qck=2(Tj).
[GRAPHIC] [TIFF OMITTED] TP24MR22.037

    Where:
    Qck=1(Tj) = BL(Tj), the 
space cooling capacity delivered by the unit in matching the building 
load at temperature Tj, in Btu/h. The matching occurs with 
the unit operating at compressor speed k = i.
[GRAPHIC] [TIFF OMITTED] TP24MR22.038

EERk=i(Tj) = the steady-state energy efficiency 
ratio of the test unit when operating at a compressor speed of k = i 
and temperature Tj, Btu/h per W.
Obtain the fractional bin hours for the cooling season, nj/
N, from Table 19 of this section. For each temperature bin where the 
unit operates at an intermediate compressor speed, determine the energy 
efficiency ratio EERk=i(Tj) using the following 
equations,
For each temperature bin where 
Qck=1(Tj) < BL(Tj) < 
Qck=v(Tj),
[GRAPHIC] [TIFF OMITTED] TP24MR22.039

where:

EERk=1(Tj) is the steady-state energy 
efficiency ratio of the test unit when operating at minimum 
compressor speed and temperature Tj, in Btu/h per W, calculated 
using capacity Qck=1(Tj) calculated 
using Equation 4.1.4-1 and electrical power consumption 
Eck=1(Tj) calculated using Equation 
4.1.4-2;
EERk=v(Tj) is the steady-state energy 
efficiency ratio of the test unit when operating at intermediate 
compressor speed and temperature Tj, in Btu/h per W, calculated 
using capacity Qck=v(Tj) calculated 
using Equation 4.1.4-3 and electrical power consumption 
Eck=v(Tj) calculated using Equation 
4.1.4-4;
EERk=2(Tj) is the steady-state energy 
efficiency ratio of the test unit when operating at full compressor 
speed and temperature Tj, Btu/h per W, calculated using capacity 
Qck=2(Tj) and electrical power 
consumption Eck=2(Tj), both 
calculated as described in section 4.1.4 of this appendix; and
BL(Tj) is the building cooling load at temperature 
Tj, Btu/h.

[[Page 16878]]

4.1.4.2.2 Variable-Speed Non-Communicating Coil-Only Air Conditioners 
or Heat Pumps

    If the unit alternates between high (k=2) and low (k=1) compressor 
capacity to satisfy the building cooling load at temperature 
Tj, Qck=1(Tj) < 
BL(Tj) < Qck=2(Tj).
[GRAPHIC] [TIFF OMITTED] TP24MR22.040

[GRAPHIC] [TIFF OMITTED] TP24MR22.041

Xk=2(Tj) = 1-Xk=1(Tj), the 
cooling mode, high capacity load factor for temperature bin j 
(dimensionless).
Obtain the fractional bin hours for the cooling season, nj/
N, from Table 19. Obtain Qck=1(Tj), 
Eck=1(Tj), 
Qck=2(Tj), and 
Eck=2(Tj) as described in section 
4.1.4 of this appendix.
* * * * *

4.2 * * *

Evaluate the building heating load using
[GRAPHIC] [TIFF OMITTED] TP24MR22.042

where,

Tj = the outdoor bin temperature, [deg]F;
Tzl = the zero-load temperature, [deg]F, which varies by 
climate region according to Table 20;
C = slope (adjustment) factor, which varies by climate region 
according to Table 20. When calculating building load for a 
variable-speed compressor system, substitute CVS for C;
Qc(95 [deg]F) = the cooling capacity at 95 [deg]F 
determined from the A or A2 test, Btu/h. For heating-only 
heat pump units, replace Qc(95 [deg]F) in Equation 4.2-2 
with Qh(47 [deg]F);
Qh(47 [deg]F) = the heating capacity at 47 [deg]F 
determined from the H1 test for units having a single-speed 
compressor, H12 for units having a two-capacity 
compressor, and H1N test for units having a variable-
speed compressor, Btu/h.
* * * * *

4.2.3 * * *

    The calculation of the Equation 4.2-1 quantities differ depending 
upon whether the heat pump would operate at low capacity (section 
4.2.3.1 of this appendix), cycle between low and high capacity (section 
4.2.3.2 of this appendix), or operate at high capacity (sections 
4.2.3.3 and 4.2.3.4 of this appendix) in responding to the building 
load. For heat pumps that lock out low capacity operation at low 
outdoor temperatures, the outdoor temperature at which the unit locks 
out must be that specified by the manufacturer in the certification 
report so that the appropriate equations can be selected.
* * * * *

4.2.3.4 Heat Pump Must Operate Continuously at High (k=2) Compressor 
Capacity at Temperature Tj, BL(Tj) = 
Qhk=2(Tj)

[[Page 16879]]

[GRAPHIC] [TIFF OMITTED] TP24MR22.043

4.2.4 * * *

    a. Minimum Compressor Speed.
    For units other than variable-speed non-communicating coil-only 
heat pumps, evaluate the space heating capacity, 
Qhk=1(Tj), and electrical power 
consumption, Ehk=1(Tj), of the heat 
pump when operating at minimum compressor speed and outdoor temperature 
Tj using
[GRAPHIC] [TIFF OMITTED] TP24MR22.044

where Qhk=1(62) and 
Ehk=1(62) are determined from the H01 
test, Qhk=1(47) and 
Ehk=1(47) are determined from the H11 
test, and all four quantities are calculated as specified in section 
3.7 of this appendix.
    For variable-speed non-communicating coil-only heat pumps, when 
Tj is greater than or equal to 47 [deg]F, evaluate the space 
heating capacity, Qhk=1(Tj), and 
electrical power consumption, 
Ehk=1(Tj), of the heat pump when 
operating at minimum compressor speed as described in Equations 4.2.4-1 
and 4.2.4-2, respectively. When Tj is less than 47 [deg]F, 
evaluate the space heating capacity, 
Qhk=1(Tj), and electrical power 
consumption, Ehk=1(Tj) using

[[Page 16880]]

[GRAPHIC] [TIFF OMITTED] TP24MR22.045

and
[GRAPHIC] [TIFF OMITTED] TP24MR22.046

where Qhk=1(47) and 
Ehk=1(47) are determined from the H11 
test, and both quantities are calculated as specified in section 3.7 of 
this appendix; Qhk=1(35) and 
Ehk=1(35) are determined from the H21 
test, and are calculated as specified in section 3.9 of this appendix; 
Qhk=1(17) and Ehk=1(17) are 
determined from the H31 test, and are calculated as 
specified in section 3.10 of this appendix; and 
Qhk=2(Tj) and 
Ehk=2(Tj) are calculated as described 
in section 4.2.4.c or 4.2.4.d of this appendix, as appropriate.
    b. Minimum Compressor Speed for Minimum-speed-limiting Variable-
speed Heat Pumps: For units other than variable-speed non-communicating 
coil-only heat pumps, evaluate the space heating capacity, 
Qhk=1(Tj), and electrical power 
consumption, Ehk=1(Tj), of the heat 
pump when operating at minimum compressor speed and outdoor temperature 
Tj using

[[Page 16881]]

[GRAPHIC] [TIFF OMITTED] TP24MR22.047

where Qhk=1(62) and 
Ehk=1(62) are determined from the H01 
test, Qhk=1(47) and 
Ehk=1(47) are determined from the H11 
test, and all four quantities are calculated as specified in section 
3.7 of this appendix; Qhk=v(35) and 
Ehk=v(35) are determined from the H2v 
test and are calculated as specified in section 3.9 of this appendix; 
and Qhk=v(Tj) and 
Ehk=v(Tj) are calculated using 
equations 4.2.4-7 and 4.2.4-8, respectively.
    For variable-speed non-communicating coil-only heat pumps, evaluate 
the space heating capacity, Qhk=1(Tj), 
and electrical power consumption, 
Ehk=1(Tj), of the heat pump as 
described in section 4.2.4.a, using Equations 4.2.4-1, 4.2.4-2, 4.2.4-3 
and 4.2.4-4, as appropriate.
    c. Full Compressor Speed for Heat Pumps for which the 
H42 test is not conducted.
    Evaluate the space heating capacity, 
Qhk=2(Tj), and electrical power 
consumption, Ehk=2(Tj), of the heat 
pump when operating at full compressor speed and outdoor temperature 
Tj using
[GRAPHIC] [TIFF OMITTED] TP24MR22.048

and

[[Page 16882]]

[GRAPHIC] [TIFF OMITTED] TP24MR22.049

    Determine Qhk=N(47) and 
Ehk=N(47) from the H1N test and the 
calculations specified in section 3.7 of this appendix. See section 
3.6.4.b of this appendix regarding determination of the capacity 
Qhcalck=2(47) and power input 
Ehcaclk=2(47) used in the HSPF2 calculations to 
represent the H12 Test. Determine 
Qhk=2(35) and Ehk=2(35) 
from the H22 test and the calculations specified in section 
3.9 of this appendix or, if the H22 test is not conducted, 
by conducting the calculations specified in section 3.6.4 of this 
appendix. Determine Qhk=2(17) and 
Ehk=2(17) from the H32 test and the 
methods specified in section 3.10 of this appendix.
* * * * *
    e. Intermediate Compressor Speed. For units other than variable-
speed non-communicating coil-only heat pumps, calculate the space 
heating capacity, Qhk=v(Tj), and 
electrical power consumption, 
Ehk=v(Tj), of the heat pump when 
operating at outdoor temperature Tj and the intermediate 
compressor speed used during the section 3.6.4 H2V test 
using
[GRAPHIC] [TIFF OMITTED] TP24MR22.050

where Qhk=v(35) and 
Ehk=v(35) are determined from the H2V 
test and calculated as specified in section 3.9 of this appendix. 
Approximate the slopes of the k=v intermediate speed heating capacity 
and electrical power input curves, MQ and ME, as 
follows:
[GRAPHIC] [TIFF OMITTED] TP24MR22.051

    Use Equations 4.2.4-1 and 4.2.4-2, respectively, to calculate 
Qhk=1(35) and Ehk=1(35), 
whether or not the heat pump is a minimum-speed-limiting variable-speed 
heat pump.
    For variable-speed non-communicating coil-only heat pumps, there is 
no intermediate speed.

4.2.4.1 Steady-State Space Heating Capacity When Operating at Minimum 
Compressor Speed is Greater Than or Equal to the Building Heating Load 
at Temperature Tj, Qhk=1(Tj 
=BL(Tj).

Evaluate the Equation 4.2-1 quantities
[GRAPHIC] [TIFF OMITTED] TP24MR22.052

as specified in section 4.2.3.1 of this appendix. Except now use 
Equations 4.2.4-1 and 4.2.4-2 (for heat pumps that are not minimum-
speed-limiting and are not variable-speed non-communicating coil-only 
heat pumps), Equations 4.2.4-1, 4.2.4-2, 4.2.4-3 and 4.2.4-4 as 
appropriate (for variable-speed non-communicating coil-only heat 
pumps), or Equations 4.2.4-5 and 4.2.4.-6 (for minimum-speed-limiting 
variable-speed heat pumps that are not variable-speed non-communicating 
coil-only heat pumps) to evaluate 
Qhk=1(Tj) and 
Ehk=1(Tj), respectively, and replace 
section 4.2.3.1 references to ``low capacity'' and section 3.6.3 of 
this

[[Page 16883]]

appendix with ``minimum speed'' and section 3.6.4 of this appendix.

4.2.4.2 Heat Pump Operates at an Intermediate Compressor Speed (k=i) 
or, for a Variable-Speed Non-Communicating Coil-Only Heat Pump, Cycles 
Between High and Low Speeds, in Order to Match the Building Heating 
Load at a Temperature Tj, 
Qhk=1(Tj) j) 
hk=2(Tj).

    For units that are not variable-speed non-communicating coil-only 
heat pumps, calculate
[GRAPHIC] [TIFF OMITTED] TP24MR22.053

and [delta](Tj) is evaluated using Equation 4.2.3-3, while
    Qhk=i(Tj) = BL(Tj), the 
space heating capacity delivered by the unit in matching the building 
load at temperature (Tj), in Btu/h. The matching occurs with 
the heat pump operating at compressor speed k=i, and
    COPk=i(Tj) = the steady-state coefficient of 
performance of the heat pump when operating at compressor speed k=i and 
temperature Tj (dimensionless).
    For each temperature bin where the heat pump operates at an 
intermediate compressor speed, determine 
COPk=i(Tj) using the following equations,
    For each temperature bin where 
Qhk=1(Tj) j) 
hk=v(Tj),
[GRAPHIC] [TIFF OMITTED] TP24MR22.054

    For each temperature bin where 
Qhk=v(Tj) <=BL(Tj) 
hk=2(Tj),
[GRAPHIC] [TIFF OMITTED] TP24MR22.055


[[Page 16884]]


where:

COPhk=1(Tj) is the steady-state 
coefficient of performance of the heat pump when operating at 
minimum compressor speed and temperature Tj, dimensionless, 
calculated using capacity Qhk=1(Tj) 
calculated using Equation 4.2.4-1 or 4.2.4-3 and electrical power 
consumption Ehk=1(Tj) calculated 
using Equation 4.2.4-2 or 4.2.4-4;
COPhk=v(Tj) is the steady-state 
coefficient of performance of the heat pump when operating at 
intermediate compressor speed and temperature Tj, dimensionless, 
calculated using capacity Qhk=v(Tj) 
calculated using Equation 4.2.4-7 and electrical power consumption 
Ehk=v(Tj) calculated using Equation 
4.2.4-8;
COPhk=2(Tj) is the steady-state 
coefficient of performance of the heat pump when operating at full 
compressor speed and temperature Tj (dimensionless), calculated 
using capacity Qhk=2(Tj) and 
electrical power consumption 
Ehk=2(Tj), both calculated as 
described in section 4.2.4; and
BL(Tj) is the building heating load at temperature 
Tj, in Btu/h.
[GRAPHIC] [TIFF OMITTED] TP24MR22.056

* * * * *
[FR Doc. 2022-04269 Filed 3-23-22; 8:45 am]
BILLING CODE 6450-01-P