`[Federal Register Volume 90, Number 4 (Tuesday, January 7, 2025)]
[Rules and Regulations]
[Pages 1224-1285]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-30852]



[[Page 1223]]

Vol. 90

Tuesday,

No. 4

January 7, 2025

Part II





Department of Energy





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10 CFR Parts 429 and 430





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

  Federal Register / Vol. 90 , No. 4 / Tuesday, January 7, 2025 / Rules 
and Regulations  

[[Page 1224]]


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DEPARTMENT OF ENERGY

10 CFR Parts 429 and 430

[EERE-2022-BT-TP-0028]
RIN 1904-AF49


Energy Conservation Program: Test Procedure for Central Air 
Conditioners and Heat Pumps

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

ACTION: Final rule.

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SUMMARY: This final rule amends the Federal test procedure for central 
air conditioners and heat pumps (``CAC/HPs'') to incorporate by 
reference the latest versions of the applicable industry standards. 
Specifically, DOE is incorporating by reference the latest version of 
the relevant industry consensus test standard, AHRI 210/240-2024 (I-P) 
for the current test procedure for CAC/HPs (``appendix M1'') for 
measuring the current cooling and heating metrics--seasonal energy 
efficiency ratio 2 (``SEER2'') and heating seasonal performance factor 
2 (``HSPF2''). DOE is incorporating by reference the new industry 
consensus test standard, AHRI 1600-2024 (I-P), for a new test procedure 
(``appendix M2'') for CAC/HPs that adopts two new metrics--seasonal 
cooling and off-mode rating efficiency (``SCORE'') and seasonal heating 
and off-mode rating efficiency (``SHORE''). Testing to the SCORE and 
SHORE metrics would not be required until such time as compliance is 
required with any amended energy conservation standard based on the new 
metrics. Additionally, DOE is amending certain provisions of DOE's 
regulations related to representations and enforcement for CAC/HPs.

DATES: The effective date of this rule is February 6, 2025. The 
amendments will be mandatory for product testing starting July 7, 2025. 
Manufacturers will be required to use the amended test procedure until 
the compliance date of any final rule establishing amended energy 
conservation standards based on the newly established test procedure. 
At such time, manufacturers will be required to begin using the newly 
established test procedure.
    The incorporation by reference of certain publications listed in 
this rule is approved by the Director of the Federal Register on 
February 6, 2025.

ADDRESSES: 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, not all documents listed in the index may be publicly 
available, such as those containing information that is exempt from 
public disclosure.
    A link to the docket web page can be found at www.regulations.gov/docket/EERE-2022-BT-TP-0028. The docket web page contains instructions 
on how to access all documents, including public comments, in the 
docket.
    For further information on how to review the docket contact the 
Appliance and Equipment Standards Program staff at (202) 287-1445 or by 
email: [email protected].

FOR FURTHER INFORMATION CONTACT: 
    Dr. Pradeep Prathibha, U.S. Department of Energy, Office of Energy 
Efficiency and Renewable Energy, Building Technologies Office, EE-5B, 
1000 Independence Avenue SW, Washington, DC 20585-0121. Telephone: 
(240) 255-0630. 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) 586-4798. Email: [email protected].

SUPPLEMENTARY INFORMATION: DOE maintains previously approved 
incorporations by reference and incorporates by reference the following 
industry standards into 10 CFR parts 429 and 430:
    AHRI Standard 210/240-2024 (I-P), Performance Rating of Unitary 
Air-conditioning and Air-source Heat Pump Equipment, copyright 2024 
(``AHRI 210/240-2024'').
    AHRI Standard 1600-2024 (I-P), Performance Rating of Unitary Air-
conditioning and Air-source Heat Pump Equipment, copyright 2024 (``AHRI 
1600-2024'').
    Copies of AHRI 210/240-2024 and AHRI 1600-2024 can be obtained from 
the Air-Conditioning, Heating, and Refrigeration Institute (AHRI), 2311 
Wilson Blvd., Suite 400, Arlington, VA 22201, (703) 524-8800, or online 
at: www.ahrinet.org.
    ANSI/ASHRAE Standard 16-2016, Method of Testing for Rating Room Air 
Conditioners, Packaged Terminal Air Conditioners, and Packaged Terminal 
Heat Pumps for Cooling and Heating Capacity, ANSI approved November 1, 
2016 (``ANSI/ASHRAE 16'').
    ANSI/ASHRAE Standard 37-2009, Methods of Testing for Rating 
Electrically Driven Unitary Air-Conditioning and Heat Pump Equipment, 
ANSI-approved June 25, 2009 (``ASHRAE 37-2009'').
    ANSI/ASHRAE Standard 116-2010, Methods of Testing for Rating 
Seasonal Efficiency of Unitary Air Conditioners and Heat Pumps, ANSI 
approved February 24, 2010 (``ANSI/ASHRAE 116-2010'').
    Copies of ANSI/ASHRAE 16, ASHRAE 37-2009, and ANSI/ASHRAE 116-2010 
can be purchased from the American Society of Heating, Refrigerating, 
and Air-Conditioning Engineers (``ASHRAE'') website at www.ashrae.org/resources--publications.
    See section IV.N of this document for further discussion of these 
standards.

Table of Contents

I. Authority and Background
    A. Authority
    B. Background
II. Synopsis of the Final Rule
III. Discussion
    A. Scope of Applicability
    B. Updates to Industry Standards
    1. AHRI 210/240-2024
    2. AHRI 1600-2024
    3. ANSI/ASHRAE 37-2009
    4. ANSI/ASHRAE 16-2016
    5. ANSI/ASHRAE 116-2010
    C. Revised CAC/HP Test Procedure
    D. Efficiency Metrics
    1. Metrics Applicable to Appendix M1
    2. Metrics Applicable to Appendix M2
    E. Near-Term Changes in the CAC/HP Test Procedure
    1. Controls Verification Procedure for Variable Speed Systems
    2. Low-Temperature Heating Performance
    3. Cut-Out and Cut-In Temperature Verification
    4. Low-Static Single-Split Blower-Coil System Definition and 
Testing Provisions
    5. Mandatory Constant Circulation Systems
    6. Provisions for Outdoor Units With No Match
    7. Inlet and Outlet Duct Configurations
    8. Heat Comfort Controllers
    F. Long-Term Changes in the CAC Test Procedure
    1. Power Consumption of Auxiliary Components
    2. Impact of Defrost on Performance
    3. Updates to Building Load Lines and Temperature Bin Hours
    4. Default Fan Power Coefficients for Coil-Only Systems
    5. Air Flow Limits To Address Inadequate Dehumidification
    G. General Comments Received in Response to the April 2024 NOPR
    H. Represented Values
    1. Represented Values for the Federal Trade Commission
    2. Off-Mode Power
    3. AEDM Tolerance for SCORE and SHORE
    4. Removal of the AEDM Exception for Split-System CAC/HPs
    I. Enforcement Provisions

[[Page 1225]]

    1. Verifying Cut-Out and Cut-In Temperatures
    2. Controls Verification Procedure
    J. Test Procedure Costs and Impacts
    1. Appendix M1
    2. Appendix M2
    K. Effective and Compliance Dates
IV. Procedural Issues and Regulatory Review
    A. Review Under Executive Orders 12866, 13563, and 14094
    B. Review Under the Regulatory Flexibility Act
    1. Descriptions of Reasons for Action
    2. Objectives of, and Legal Basis for, Rule
    3. Description and Estimate of Small Entities Regulated
    4. Description and Estimate of Compliance Requirements
    5. Duplication, Overlap, and Conflict With Other Rules and 
Regulations
    1. Certification Statement
    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. Congressional Notification
    N. Description of Materials Incorporated by Reference
V. 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 the U.S. Department of Energy 
(``DOE'') is authorized to establish and amend energy conservation 
standards and test procedures. (42 U.S.C. 6292 (a)(3)) DOE's test 
procedure for CAC/HPs is currently prescribed at 10 CFR part 430, 
subpart B, appendix M1 (``appendix M1''). The following sections 
discuss DOE's authority to establish and amend the test procedure for 
CAC/HPs and relevant background information regarding DOE's 
consideration of the test procedure for this product.

A. Authority

    The Energy Policy and Conservation Act, Pub. L. 94-163, 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, as codified) Title III, Part B of EPCA \2\ 
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, 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), which reflects the last statutory amendments that impact 
Parts A and A-1 of EPCA.
    \2\ For editorial reasons, upon codification in the U.S. Code, 
Part B was redesignated Part A.
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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 under EPCA (42 U.S.C. 6295(s)), and (2) 
making other representations about the efficiency of those products (42 
U.S.C. 6293(c)). Similarly, DOE must use these test procedures to 
determine whether the products comply with any 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 shall 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 (as determined by the Secretary) or period of use and shall not 
be unduly burdensome to conduct. (42 U.S.C. 6293(b)(3))
    EPCA also requires that, at least once every seven years, DOE 
evaluate test procedures for each type of covered product, including 
CAC/HPs, to determine whether amended test procedures would more 
accurately or fully comply with the requirements for the test 
procedures to not be unduly burdensome to conduct and be reasonably 
designed to produce test results that reflect energy efficiency, energy 
use, and estimated operating costs during a representative average use 
cycle or period of use. (42 U.S.C. 6293(b)(1)(A))
    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. The comment period on a proposed rule 
to amend a test procedure shall be at least 60 days and may not exceed 
270 days. 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. (42 U.S.C. 6293(b)(2)). If DOE determines 
that test procedure revisions are not appropriate, DOE must publish its 
determination not to amend the test procedures.
    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 requires 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 notice of proposed rulemaking (``NOPR'') to amend 
its 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).
    In addition, EPCA requires that DOE amend its test procedures for 
all covered products to integrate measures of standby mode and off-mode 
energy consumption into the overall energy efficiency, energy 
consumption, or other

[[Page 1226]]

energy descriptor, unless the current test procedure already 
incorporates the standby mode and off-mode energy consumption, or if 
such integration is technically infeasible. (42 U.S.C. 
6295(gg)(2)(A)(i)-(ii)) If an integrated test procedure is technically 
infeasible, DOE must prescribe separate standby mode and off-mode 
energy use test procedures for the covered product, if a separate test 
is technically feasible. (42 U.S.C. 6295(gg)(2)(A)(ii)) Any such 
amendment must consider the most current versions of the International 
Electrotechnical Commission (IEC) Standard 62301 \3\ and IEC Standard 
62087 \4\ as applicable. (42 U.S.C. 6295(gg)(2)(A)) DOE is publishing 
this final rule in satisfaction of the seven-year review requirement 
specified in EPCA. (42 U.S.C. 6293(b)(1)(A))
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    \3\ IEC 62301, Household electrical appliances--Measurement of 
standby power (Edition 2.0, 2011-01).
    \4\ IEC 62087, Audio, video and related equipment--Methods of 
measurement for power consumption (Edition 1.0, Parts 1-6: 2015, 
Part 7: 2018).
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B. Background

    On April 5, 2024, DOE published in the Federal Register a notice of 
proposed rulemaking (``NOPR'') (``April 2024 NOPR'') proposing to 
update the Federal test procedure for CAC/HPs by: (1) incorporating by 
reference at appendix M1 the most recent draft version of the AHRI 
Standard 210/240 industry test procedure, AHRI 210/240-202X Draft, for 
measuring SEER2 and HSPF2; and (2) establishing a new test procedure at 
10 CFR part 430, subpart B, appendix M2 (``appendix M2'') that 
references the draft new industry test procedure, AHRI 1600-202X Draft, 
for measuring new efficiency metrics, seasonal cooling and off mode 
rating efficiency (``SCORE''), and seasonal heating and off mode rating 
efficiency (``SHORE''). 89 FR 24206. Copies of the AHRI drafts were 
added to the docket for this rulemaking for review by interested 
parties.5 6 As stated in the April 2024 NOPR, if AHRI 210/
240-202X Draft and AHRI 1600-202X Draft were to be finalized and 
formally adopted, DOE's intention would be to reference the final 
published version of AHRI 210/240 and AHRI 1600 in DOE's subsequent 
test procedure final rule. 89 FR 24206, 24209. DOE held a public 
meeting webinar on April 25, 2024 to discuss the proposed amendments to 
the CAC/HP test procedure presented in the April 2024 NOPR.
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    \5\ The AHRI 210/240-202X Draft test procedure is available in 
the docket for this rulemaking at: www.regulations.gov/document/EERE-2022-BT-TP-0028-0017.
    \6\ The AHRI 1600-202X Draft test procedure is available in the 
docket for this rulemaking at: www.regulations.gov/document/EERE-2022-BT-TP-0028-0018.
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    DOE received comments in response to the April 2024 NOPR from the 
interested parties listed in table I.1.

            Table I-1--List of Commenters With Written Submissions in Response to the April 2024 NOPR
----------------------------------------------------------------------------------------------------------------
                                          Reference in this
             Commenter(s)                    final rule        Comment No. in the docket      Commenter type
----------------------------------------------------------------------------------------------------------------
Air-Conditioning, Heating, and         AHRI..................  25.......................  Trade Association.
 Refrigeration Institute.
Pacific Gas and Electric Company, San  CA IOUs...............  32.......................  Utilities.
 Diego Gas and Electric, and Southern
 California Edison; collectively, the
 California Investor-Owned Utilities.
Carrier Global Corporation...........  Carrier...............  29.......................  Manufacturer.
Copeland LP..........................  Copeland..............  31.......................  Manufacturer.
Daikin Comfort Technologies North      Daikin................  36 and 40................  Manufacturer.
 America Inc.
GE Appliances........................  GE Appliances.........  37.......................  Manufacturer.
Heating, Air-conditioning &            HARDI.................  26.......................  Trade Association.
 Refrigeration Distributors
 International.
Johnson Controls.....................  JCI...................  35.......................  Manufacturer.
Appliance Standards Awareness          Joint Advocates.......  30.......................  Efficiency
 Project, National Consumer Law                                                            Organization,
 Center, and New York State Energy                                                         Consumer Advocacy
 Research and Development Authority.                                                       Organization, and
                                                                                           State Agency.
Keith Rice...........................  Keith Rice............  33.......................  HVAC R&D Engineer.
Lennox International Inc.............  Lennox................  24.......................  Manufacturer.
LG Electronics U.S.A., Inc...........  LG....................  38.......................  Manufacturer.
Mitsubishi Electric US...............  Mitsubishi............  28.......................  Manufacturer.
National Comfort Products............  NCP...................  27.......................  Manufacturer.
Northwest Energy Efficiency Alliance.  NEEA..................  39.......................  Efficiency
                                                                                           Organization.
Rheem Manufacturing Company..........  Rheem.................  34.......................  Manufacturer.
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    A parenthetical reference at the end of a comment quotation or 
paraphrase provides the location of the item in the public record.\7\ 
To the extent that interested parties have provided written comments 
that are substantively consistent with any oral comments provided 
during the April 25, 2024 public meeting, DOE cites the written 
comments throughout this final rule. DOE did not identify any oral 
comments provided during the April 25, 2024, public meeting that are 
not substantively addressed by written comments.
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    \7\ The parenthetical reference provides a reference for 
information located in the docket of DOE's rulemaking to develop 
test procedures for CAC/HPs. (Docket No. EERE-2022-BT-TP-0028, which 
is maintained at: www.regulations.gov). The references are arranged 
as follows: (commenter name, comment docket ID number at page of 
that document).
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    In May 2024, AHRI finalized AHRI 210/240-202X Draft and AHRI 1600-
202X Draft without substantial change, and published AHRI Standard 210/
240-2024, ``Performance Rating of Unitary Air-conditioning and Air-
source Heat Pump Equipment'' (``AHRI 210/240-2024''), and AHRI Standard 
1600-2024, ``Performance Rating of Unitary Air-conditioning and Air-
source Heat Pump Equipment'' (``AHRI 1600-2024''), respectively.

II. Synopsis of the Final Rule

    In this final rule, DOE is updating its regulations for CAC/HPs by: 
(1) amending appendix M1 to incorporate by reference the latest 
industry standard, AHRI 210/240-2024, while maintaining the current 
efficiency metrics EER2, SEER2 and HSPF2; and (2) establishing a new 
appendix M2 that references the new industry test

[[Page 1227]]

procedure, AHRI 1600-2024, for measuring new efficiency metrics, EER, 
SCORE and SHORE. Appendix M2 would be the applicable test method for 
CAC/HPs for any standards denominated in terms of SCORE and SHORE. Use 
of appendix M2 would not be required until such time as compliance is 
required with any amended energy conservation standard based on the new 
metrics, should DOE adopt such standards. After the date on which 
compliance with appendix M2 would be required, appendix M1 would no 
longer be required as part of the Federal test procedure. DOE is also 
amending certain provisions within DOE's regulations for representation 
and enforcement consistent with the proposed test procedure amendments.
    Table II.1 summarizes the adopted changes to the amended appendix 
M1 and the new appendix M2 test procedures, as well as the reason for 
the adopted change.

  Table II-1--Summary of Changes in Amended Appendix M1 and New Appendix M2 Test Procedures Relative to Current
                                                 Test Procedure
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                                           Appendix M1 test         Appendix M2 test
DOE test procedure prior to amendment         procedure                procedure               Attribution
----------------------------------------------------------------------------------------------------------------
Incorporates by reference AHRI 210/    Incorporates by          Incorporates by          Updates to the
 240-2008.                              reference AHRI 210/240-  reference AHRI 1600-     applicable industry
                                        2024.                    2024.                    test procedures.
Includes provisions for determining    Maintains provisions     Includes provisions for  Updates to the
 SEER2, HSPF2, EER2, and PW,OFF.        for determining SEER2,   determining SCORE and    applicable industry
                                        HPSF2, EER2, and         SHORE and maintains      test procedures.
                                        PW,OFF.                  provisions for
                                                                 determining EER (same
                                                                 as EER2).
Includes certain CAC/HP provisions     Includes provisions to   Includes provisions to   Improve
 regarding determination of             remove the alternative   remove the AEDM          representativeness of
 represented values in 10 CFR 429.16.   efficiency               exception for split-     test procedure.
                                        determination method     systems, to extend the
                                        (``AEDM'') exception     AEDM tolerance
                                        for split-systems in     requirement to SCORE
                                        10 CFR 429.16.           and SHORE, and to no
                                                                 longer require
                                                                 representations of the
                                                                 PW,OFF metric in 10
                                                                 CFR 429.16.
Does not include certain CAC/HP-       Includes CAC/HP-         Includes CAC/HP-         Clarify how DOE will
 specific enforcement provisions in     specific enforcement     specific enforcement     conduct enforcement
 10 CFR 429.134(k).                     provisions regarding     provisions regarding     testing.
                                        verification of cut-     verification of cut-
                                        out and cut-in           out and cut-in
                                        temperatures and a       temperatures and a
                                        controls verification    controls verification
                                        procedure.               procedure.
----------------------------------------------------------------------------------------------------------------

    DOE has determined that the amendments to the CAC/HP test 
procedures in appendix M1 and newly established appendix M2 would not 
be unduly burdensome to conduct. Furthermore, DOE has determined that 
the amendments to appendix M1 would not alter the measured efficiency 
of CAC/HPs or require retesting or recertification solely as a result 
of DOE's adoption of the amendments to the test procedure. 
Additionally, DOE has determined that the amendments to appendix M1 
would not increase the cost of testing. Representations of energy use 
or energy efficiency would be required to be based on testing in 
accordance with the amended test procedure in appendix M1 beginning 180 
days after the date of publication of the test procedure final rule in 
the Federal Register.
    DOE has determined, however, that new appendix M2 would alter the 
measured efficiency of CAC/HPs, in part because the amended test 
procedure would adopt different energy efficiency metrics than in the 
current test procedure. Additionally, DOE has determined that testing 
according to the new appendix M2 would not increase the cost of testing 
as compared to appendix M1. Cost estimates are discussed in section 
III.J of this document. As discussed, use of appendix M2 would not be 
required until the compliance date of amended energy conservation 
standards denominated in terms of SCORE and SHORE, should DOE adopt 
such standards.
    The amendments to representation requirements in 10 CFR 429.16 
would not be required until 180 days after publication in the Federal 
Register of this final rule.
    Discussion of DOE's proposed actions are addressed in further 
detail in section III of this final rule.

III. Discussion

A. Scope of Applicability

    This rulemaking applies to CAC/HPs. DOE defines the term central 
air conditioner or central air conditioner heat pump to mean a product, 
other than a packaged terminal air conditioner or packaged terminal 
heat pump, single-phase single-package vertical air conditioner with 
cooling capacity less than 65,000 British thermal units (``Btu'') per 
hour (``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/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). For all central air conditioner and central air 
conditioning heat pump-related definitions, see appendix M or M1 of 
subpart B of this part. 10 CFR 430.2.
    Consistent with the April 2024 NOPR, DOE is not proposing any 
changes to the CAC/HP definition. However, DOE notes that the last 
sentence in the CAC/HP definition includes references to see additional 
definitions in appendices M and M1. As noted in section II, in this 
final rule, DOE is incorporating by reference the latest industry 
standards, AHRI 210/240-2024 and AHRI 1600-2024, including the relevant 
definitions

[[Page 1228]]

in these standards. Therefore, references to appendices M and M1 are no 
longer relevant in the CAC/HP definition. To prevent confusion, DOE is 
removing the last sentence in the definition that contains these 
references. 10 CFR 430.2.
    The current scope of the CACs/HP test procedure includes:
    (a) Split-system air conditioners, including single-split, multi-
head mini-split, multi-split (including variable refrigerant flow 
(``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 amending the scope of CACs/HPs covered by the test 
procedure in appendix M1 or appendix M2.

B. Updates to Industry Standards

    DOE is incorporating by reference AHRI 210/240-2024 and the 
relevant standards it references as the basis for the updated appendix 
M1 test procedure. Similarly, DOE is incorporating by reference AHRI 
1600-2024 and the relevant standards it references as the basis for the 
new appendix M2 test procedure. Incorporating each industry standard in 
full as the basis for each respective appendix would enable DOE to 
better harmonize with the industry standard and eliminate manufacturer 
burden in certifying with separate test procedures. The following 
sections discuss the referenced standards for appendices M1 and M2.
1. AHRI 210/240-2024
    In the April 2024 NOPR, DOE noted that AHRI and other relevant 
stakeholders, including DOE, worked to develop a revised AHRI 210/240 
standard, AHRI 210/240-202X Draft, that included updates to address 
issues pertaining to the CAC/HP test procedure with broad stakeholder 
consensus. 89 FR 24206, 24211-24212. DOE proposed to amend its test 
procedure for CAC/HPs at appendix M1 by incorporating by reference AHRI 
210/240-202X Draft. Id. Because AHRI 210/240-202X Draft was in draft 
form at the time of the publication of the April 2024 NOPR, DOE noted 
that it intended to update its incorporation by reference to the final 
published version of AHRI 210/240-202X Draft in the final rule, unless 
the draft version is not finalized before the final rule or there are 
substantive changes between the draft and published versions, in which 
case DOE may adopt the substance of the AHRI 210/240-202X Draft or 
provide additional opportunity for comment on the substantive changes 
to the updated industry consensus standard. Id. In May 2024, AHRI 
published the finalized AHRI 210/240 standard, AHRI 210/240-2024, which 
did not include any significant deviations from AHRI 210/240-202X 
Draft.
    AHRI, the CA IOUs, Carrier, Daikin, GE Appliances, JCI, Lennox, and 
NEEA were generally supportive of DOE`s proposal on updating appendix 
M1 by adopting the finalized AHRI 210/240 standard. (AHRI, No. 25 at p. 
3; Carrier, No. 29 at p. 4; CA IOUs, No. 32 at p. 1; Daikin, No. 36 at 
p. 1; GE Appliances, No. 37 at pp. 4-5; JCI, No. 35 at p. 1; Lennox, 
No. 24 at p. 3; NEEA, No. 39 at p. 2) AHRI commented that it supports 
the adoption of AHRI 210/240-2024 as a revised appendix M1, but with 
minimal additions and some exclusions, and will be publishing an 
addendum to AHRI 210/240-2024 that will include the aforementioned 
minimal additions that DOE established in the April 2024 NOPR, 
including revision to the definition of outdoor unit with no match. 
(AHRI, No. 25 at p. 3)
    The Joint Advocates and CA IOUs encouraged DOE to adopt AHRI 210/
240-2024 in the new CAC/HP test procedure final rule as soon as 
possible. (Joint Advocates, No. 30 at p. 1; CA IOUs, No. 32 at p. 1) 
Carrier stated that it supports the incorporation by reference of AHRI 
210/240-2024 into a revised appendix M1, but with some recommendations. 
(Carrier, No. 29 at p. 4) Rheem commented that even though it supported 
the adoption of the consensus AHRI 210/240-2024 in the updated Appendix 
M1, it was concerned that the new versions of ANSI/ASHRAE Standard 37-
2009 \8\ and ANSI/ASHRAE Standard 16-2016 \9\ with major changes, which 
are to be published in the near future, are not currently referenced in 
AHRI 210/240-2024. (Rheem, No. 34 at p. 3) Specifically, Rheem pointed 
out that once the new versions of the aforementioned ASHRAE standards 
are published, AHRI 210/240-2024 should be revised to incorporate 
references to the revised standards, and subsequently, DOE should 
update appendix M1 to incorporate the revised AHRI 210/240-2024 by 
reference. (Id. at pp. 3-4) Rheem further commented that since AHRI 
210/240-2024 cites sections of 10 CFR 429.16, and of appendix M1 to 
subpart B of 10 CFR part 430, it should be revised to ensure that these 
references to CFR are still appropriate, since DOE has proposed major 
revisions to these sections from the CFR. (Id.) Rheem pointed to the 
newly introduced enforcement provisions in 10 CFR 429.134(k), which 
require calculation of average capacity (10 CFR 
429.134(k)(4)(iii)(A)(1) and (2)) or time-averaged integrated (10 CFR 
429.134(k)(4)(iii)(A)(3)) capacity and power consumption, and Rheem 
suggested updates to appendix I of AHRI 210/240-2024 to state that 
average capacity, average power consumption, time-averaged integrated 
capacity, and time-integrated power consumption should be calculated 
according to the appropriate sections of AHRI 210/240-2024 and ANSI/
ASHRAE 16, as applicable. (Id.) Rheem pointed out that table 8 of AHRI 
210/240-2024, which lists the test conditions for CAC/HPs under test, 
does not include the details on how to measure the compressor speed for 
cooling full-speed tests (A2 and B2), and cooling minimum-speed tests 
(B1, F1, G1, and I1) for variable-speed compressor units, as currently 
specified in section 3.2.4(a) of appendix M1. (Id. at p. 4) Rheem 
commented that the aforementioned details should be added as notes 
under table 8 of AHRI 210/240-2024, after appropriate translations of 
the test nomenclature.\10\ Id.
---------------------------------------------------------------------------

    \8\ ANSI/ASHRAE 37-2009 provides a method of test for many 
categories of air-conditioning and heating products and equipment, 
including CAC/HPs.
    \9\ ANS/ASHRAE 16-2016 provides a method of test for rating room 
air conditioners, packaged terminal air conditioners, and packaged 
terminal heat pumps.
    \10\ Currently, all full-speed cooling and heating mode tests in 
appendix M1 are identified with ``2'' in the subscript of the 
relevant test, whereas AHRI 210/240-202X and AHRI 1600-202X identify 
them with the ``Full'' subscript. Similarly, all minimum-speed 
cooling and heating mode tests in appendix M1 are identified with 
``1'' in the subscript of the relevant test, whereas AHRI 210/240-
202X and AHRI 1600-202X identify them with the ``Low'' subscript.
---------------------------------------------------------------------------

    In response to Rheem's comment, DOE notes that in the April 2024 
NOPR, DOE proposed to incorporate by reference AHRI 210/240-202X draft 
and the AHRI 1600-202X draft, at revised appendix M1 and new appendix 
M2, respectively, while this final rule is updating these references to 
the final drafts, AHRI 210/240-2024 and AHRI 1600-2024. DOE has 
reviewed the finalized standards, AHRI 210/240-2024 and AHRI 1600-2024, 
and has concluded that all current references to 10 CFR 429.16 in the 
standards would

[[Page 1229]]

not require revision. Additionally, DOE clarifies that any further 
updates to appendix I of the AHRI 210/240 and AHRI 1600 standards to 
add the definitions of average capacity, average power consumption, 
time-averaged integrated capacity, and time-integrated power 
consumption will have to be initiated by AHRI, as part of an addendum. 
DOE has determined that additional definitions are not necessary at 
this time and notes that an updated appendix I to AHRI 210/240 and AHRI 
1600 is not yet available for review; therefore, DOE is not adopting 
additional definitions as recommended by Rheem at this time. Regarding 
Rheem's comment on table 8 of AHRI 210/240-2024 lacking language from 
section 3.2.4 (a) of the current appendix M1 for maintaining the same 
full compressor speed for all full-speed cooling tests, and the same 
minimum compressor speed for all minimum-speed cooling tests, DOE is 
adding provisions in section 2 of the revised appendix M1 and section 2 
of the new appendix M2, consistent with the existing requirement in 
appendix M1, as follows:
    For cooling mode tests of variable capacity systems, the compressor 
shall operate at the same cooling full speed, measured by RPM of power 
input frequency (Hz), for both AFull and BFull 
tests. Additionally, the compressor shall operate at the same cooling 
minimum speed, measured by RPM or power input frequency (Hz), for the 
BLow, FLow, GLow, and ILow 
tests.
    As noted, in May 2024, AHRI published AHRI 210/240-2024, which does 
not include any significant deviations from AHRI 210/240-202X Draft. As 
such, the adoption of AHRI 210/240-2024 in this final rule is 
consistent with the proposal to reference AHRI 210/240-202X Draft in 
the April 2024 NOPR.
    Therefore, DOE is amending its test procedure for CAC/HPs by 
incorporating by reference AHRI 210/240-2024 for use in the new 
appendix M1. Specifically, in the new test procedure for CAC/HPs at 
appendix M1, DOE is adopting sections 3 (excluding 3.2.16, 3.2.20, 
3.2.46, 3.2.51, 3.2.63, 3.2.78 and 3.2.79), 5 (excluding 5.1.6.2), 6.1-
6.3, and 6.6, and Appendices D, E, G, and K of AHRI 210/240-2024.\11\
---------------------------------------------------------------------------

    \11\ DOE notes that the substance of these provisions remains 
the same as those proposed in the April 2024 NOPR, but AHRI did some 
reorganization in moving from AHRI 210/240-202X Draft to AHRI 210/
240-2024. Consequently, the adopted section numbers cited here 
differ from those presented in DOE's proposed rule. See 89 FR 24206, 
24212.
---------------------------------------------------------------------------

    Additionally, as proposed in the April 2024 NOPR, DOE is making 
additions and deletions to the incorporations by reference for the CAC/
HP Federal test procedure (see 10 CFR 430.3) to align with the 
references made within AHRI 210/240-2024. 89 FR 24206, 24212.
    Currently, appendix M1 incorporates by reference: AMCA 210-
2007,\12\ AHRI 210/240-2008, AHRI 1230-2010,\13\ ASHRAE 23.1-2010,\14\ 
ANSI/ASHRAE 37-2009, and ASHRAE 116-2010. 10 CFR 430.3.
---------------------------------------------------------------------------

    \12\ ANSI/AMCA 210-2007, ANSI/ASHRAE 51-2007, (``AMCA 210-
2007'') Laboratory Methods of Testing Fans for Certified Aerodynamic 
Performance Rating, ANSI approved Aug. 17, 2007. A copy of AMCA 210-
2007 can be purchased from the Air Movement and Control Association 
International Inc. (``AMCA'') website at www.amca.org/store/index.php.
    \13\ 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 Aug. 2, 2010. A copy of AHRI 1230-2010 can be obtained from 
AHRI, 2111 Wilson Boulevard, Suite 500, Arlington, VA 22201, USA, 
703-524-8800, or by going to www.ahrinet.org.
    \14\ 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 Jan. 28, 
2010. A copy of ASHRAE 23.1-2010 can be obtained from the ASHRAE 
website at www.ashrae.org/resources--publications.
---------------------------------------------------------------------------

    In the amended test procedure at appendix M1, DOE is adding an 
incorporation by reference to ANSI/ASHRAE 16-2016 and removing 
incorporations by reference to AMCA 210-2007, AHRI 210/240-2008, AHRI 
1230-2010, and ASHRAE 23.1-2010. Therefore, DOE is incorporating by 
reference AHRI 210/240-2024, ANSI/ASHRAE 16-2016, ANSI/ASHRAE 37-2009, 
and ANSI/ASHRAE 116-2010, at appendix M1.
2. AHRI 1600-2024
    In parallel to the AHRI 210/240-202X Draft, AHRI and other relevant 
stakeholders, including DOE, worked to develop a forward-looking AHRI 
test procedure that would act as the successor to the AHRI 210/240-202X 
Draft and be effective in the long term (i.e., AHRI 1600-202X Draft).
    In the April 2024 NOPR, DOE proposed to establish a new test 
procedure for CAC/HPs at appendix M2 by incorporating by reference AHRI 
1600-202X Draft (in its entirety). 89 FR 24206, 24212. DOE noted that 
it intended to update its incorporation by reference to the final 
published version of AHRI 1600-202X Draft in the final rule, unless the 
draft version is not finalized before the final rule or there are 
substantive changes between the draft and published versions, in which 
case DOE may adopt the substance of the AHRI 1600-202X Draft or provide 
additional opportunity for comment on the substantive changes to the 
updated industry consensus standard. Id. In May 2024, AHRI published 
the finalized AHRI 1600 standard, AHRI 1600-2024, which did not include 
any significant deviations from AHRI 1600-202X Draft.
    Several stakeholders, namely Lennox, AHRI, Mitsubishi, Copeland, 
the CA IOUs, Rheem, Daikin, NEEA, and Carrier, appreciated DOE's 
efforts of collaborating with the stakeholders to develop the AHRI 1600 
standard, and supported its adoption at appendix M2. (Lennox, No. 24 at 
p. 4; AHRI, No. 25 at p. 3; \15\ Mitsubishi, No. 28 at p. 1; Copeland, 
No. 31 at p. 1; CA IOUs, No. 32 at p. 2; Rheem, No. 34 at p. 4; Daikin, 
No. 36 at p. 1; NEEA, No. 39 at p. 2; Carrier, No. 29 at p. 4) Rheem 
commented that in a similar vein to its comment made on AHRI 210/240-
2024 (see section III.B.1 of this document), DOE should be aware that 
the revised editions of ANSI/ASHRAE Standard 37 and ANSI/ASHRAE 
Standard 16 are currently not referenced in AHRI Standard 1600-2024. 
(Rheem, No. 34 at p. 4) Rheem further pointed to DOE`s inclusion of the 
energy efficiency metric energy efficiency ratio 2 (``EER2) in 10 CFR 
430.23(m)(2); several sections of 10 CFR 429.16 and 10 CFR 
429.134(k)(4); and sections 2, 4.1, and 4.2 of appendix M2 to subpart B 
of 10 CFR part 430, which in turn incorporate AHRI 1600-2024 by 
reference, which only includes energy efficiency ratio (``EER'') as the 
efficiency metric, and not EER2. (Id. at p. 5) Rheem stated that this 
mismatch should be resolved by either DOE revising its relevant 
references from EER2 to EER, or that AHRI 1600-2024 should be revised 
to replace all instances of EER with EER2. (Id.) Further, Rheem pointed 
out that section 4.1 of the new appendix M2 references 10 CFR 431.97, 
in relation to certification to the energy conservation standards SCORE 
and SHORE, and suggested this citation should be changed to 10 CFR 
430.32(c), which will be amended to prescribe energy conservation 
standards for CAC/HPs. (Id.) Additionally, as noted in section III.B.1 
for AHRI 210/240-2024, Rheem commented that table 8 of AHRI 1600-2024 
should contain sentences similar to section 3.2.4(a) of appendix M1, to

[[Page 1230]]

specify that for variable-speed compressor systems, the cooling full 
compressor speed for both A2 and B2 tests should be same, and the 
cooling minimum compressor speed for the B1, F1, G1, and I1 tests 
should remain the same. (Id. at p. 4)
---------------------------------------------------------------------------

    \15\ While AHRI`s comment noted support for the adoption of the 
AHRI 1600 standard at appendix M1, DOE surmises that this is a 
typographical error, and AHRI intended to express support for 
adoption at appendix M2 instead. As proposed in the April 2024 NOPR, 
appendix M1 references the draft AHRI 210/240 standard.
---------------------------------------------------------------------------

    In response to Rheem's comment regarding AHRI 210/240-2024 
retaining the EER2 metric while AHRI 1600-2024 using the EER metric, 
DOE agrees with Rheem that this mismatch has potential to confuse users 
of the test procedure. DOE notes that the EER2 metric in AHRI 210/240-
2024 is identical to the EER metric in AHRI 1600-2024. Both metrics are 
evaluated at the same test conditions and convey the same full-load 
efficiency information. Therefore, for appendix M1, which references 
AHRI 210/240-2024, DOE is retaining the EER2 metric. For appendix M2, 
which references AHRI 1600-2024, DOE is including EER as the full-load 
metric, with EER evaluated the same way as EER2 per appendix M1. DOE is 
making appropriates changes in the regulatory text at 10 CFR parts 429 
and 430, and appendix M2, to reflect this clarification. In response to 
Rheem's comment for the citation of the SCORE and SHORE energy 
conservation standards in the April 2024 NOPR, DOE agrees that the 
correct citation is to 10 CFR 430.32(c), and not 10 CFR 431.97. 
Finally, as mentioned in section III.B.1 of this document, DOE is 
adding language to section 2 of appendix M2 to explicitly state that 
for variable-capacity compressor systems, the cooling full compressor 
speeds for both AFull and BFull tests should be 
identical, and the cooling minimum compressor speed for the 
BLow, FLow, GLow, and ILow 
tests should be identical.
    As discussed, AHRI 1600-2024 does not include any significant 
deviations from AHRI 1600-202X Draft. As such, the adoption of AHRI 
1600-2024 in this final rule is consistent with the proposal to 
reference AHRI 1600-202X Draft in the April 2024 NOPR.
    DOE is amending its test procedure for CAC/HPs by incorporating by 
reference AHRI 1600-2024 for use in the new appendix M2. Specifically, 
in the new test procedure for CAC/HPs at appendix M2, DOE is adopting 
sections 3 (excluding 3.2.16, 3.2.20, 3.2.45, 3.2.50, 3.2.63, 3.2.78, 
and 3.2.79), 5 (excluding 5.1.6.2), 6 (excluding 6.1.8, 6.2, 6.3, 6.4, 
and 6.5), 11, and 12 and appendices D, E, G, K, and L of the AHRI 1600-
202X Draft in the Federal test procedure for CAC/HPs at appendix M2.
    Additionally, consistent with the April 2024 NOPR, DOE is also 
incorporating by reference ANSI/ASHRAE 16-2016, ANSI/ASHRAE 37-2009, 
and ANSI/ASHRAE 116-2010, which are referenced within AHRI 1600-2024. 
Therefore, in total, DOE is proposing to incorporate by reference AHRI 
1600-2024, ANSI/ASHRAE 16-2016, ANSI/ASHRAE 37-2009, and ANSI/ASHRAE 
116-2010, at appendix M2.
3. ANSI/ASHRAE 37-2009
    ANSI/ASHRAE 37-2009 provides a method of test for electrically 
driven unitary air-conditioning and heat pump equipment, which includes 
CAC/HPs. In the April 2024 NOPR, DOE proposed to incorporate by 
reference ANSI/ASHRAE 37-2009 at both appendix M1 and appendix M2, 
since AHRI 210/240-202X Draft and AHRI 1600-202X Draft both reference 
test instructions in ANSI/ASHRAE 37-2009. 89 FR 24206, 24212. The 
finalized versions of these draft standards, AHRI 210/240-2024 and the 
AHRI 1600-2024, also reference ANSI/ASHRAE 37-2009. More specifically, 
sections 5, 6, 8, and 11 and appendices C, D, E, I, and J of AHRI 210/
240-2024 and AHRI 1600-2024 refer to methods of test in ANSI/ASHRAE 37-
2009.
    DOE currently incorporates by reference ANSI/ASHRAE 37-2009 in 10 
CFR part 430, subpart B, and the current incorporation by reference 
applies to the current Federal test procedure for CAC/HPs specified at 
appendix M1. Given that AHRI 210/240-2024 Draft references ANSI/ASHRAE 
37-2009 for several test instructions, DOE has concluded, consistent 
with the April 2024 NOPR, that it is appropriate to maintain the 
existing incorporation by reference of ANSI/ASHRAE 37-2009 in appendix 
M1. Additionally, given that AHRI 1600-2024 references ANSI/ASHRAE 37-
2009 for several test instructions, DOE has concluded, consistent with 
the April 2024 NOPR, that it is appropriate to incorporate by reference 
ANSI/ASHRAE 37-2009 for use with appendix M2.
4. ANSI/ASHRAE 16-2016
    ANSI/ASHRAE 16-2016, which provides a method of test for rating 
room air conditioners, packaged terminal air conditioners, and packaged 
terminal heat pumps, is referenced for testing CAC/HPs by both the AHRI 
210/240-202X Draft and the AHRI 1600-202X Draft. Consequently, in the 
April 2024 NOPR, DOE proposed to incorporate by reference ANSI/ASHRAE 
16-2016 at both appendix M1 and appendix M2. 89 FR 24206, 24213. The 
finalized versions of the AHRI draft standards, AHRI 210/240-2024 and 
AHRI 1600-2024, also reference ANSI/ASHRAE 16-2016. More specifically, 
section 5.1.1 of AHRI 210/240-2024 and AHRI 1600-2024 refer to testing 
of non-ducted CAC/HPs from provisions in ANSI/ASHRAE 16-2016, or by 
using a combination of provisions in ANSI/ASHRAE 37-2009 and ANSI/
ASHRAE 116-2016.
    Currently, ANSI/ASHRAE 16-2016 is not incorporated by reference in 
appendix M1. DOE has concluded that testing conducted per ANSI/ASHRAE 
16-2016 for non-ducted CAC/HPs will not impact ratings in comparison to 
testing conducted per provisions in ANSI/ASHRAE 37-2009 and ANSI/ASHRAE 
116-2010. Thus, given that AHRI 210/240-2024 and AHRI 1600-2024 refer 
to ANSI/ASHRAE 16-2016 as an option for testing of non-ducted CAC/HPs, 
and it does not impact ratings, DOE has concluded, consistent with the 
April 2024 NOPR, that it is appropriate to incorporate by reference 
ANSI/ASHRAE 16-2016 for appendices M1 and M2.
5. ANSI/ASHRAE 116-2010
    ANSI/ASHRAE 116-2010, which provides a method of test for unitary 
air conditioners and heat pumps with a cooling capacity of 65,000 Btu/h 
and less, is referenced for testing CAC/HPs by both AHRI 210/240-202X 
Draft and AHRI 1600-202X Draft. Consequently, in the April 2024 NOPR, 
DOE proposed to incorporate by reference ANSI/ASHRAE 116-2010 at both 
appendix M1 and appendix M2. 89 FR 24206, 24213. The finalized versions 
of the AHRI draft standards, AHRI 210/240-2024 and AHRI 1600-2024, also 
reference ANSI/ASHRAE 116-2010. More specifically, sections 5, 6, 8, 
and 11 and appendices D and E of AHRI 210/240-2024 and AHRI 1600-2024 
refer to methods of test in ANSI/ASHRAE 116-2010.
    Given that AHRI 210/240-2024 references ANSI/ASHRAE 116-2010 for 
several test instructions, DOE has concluded, consistent with the April 
2024 NOPR, that it is appropriate to maintain the incorporation by 
reference of ANSI/ASHRAE 116-2010 in appendix M1. Additionally, given 
that the AHRI 1600-2024 Draft references ANSI/ASHRAE 116-2010 for 
several test instructions, DOE has concluded, consistent with the April 
2024 NOPR, that it is appropriate to incorporate by reference ANSI/
ASHRAE 116-2010 for use with appendix M2.

C. Revised CAC/HP Test Procedure

    As discussed, EPCA requires that test procedures for each type of 
covered product, including CAC/HPs, not be unduly burdensome to conduct 
and be reasonably designed to produce test

[[Page 1231]]

results that reflect energy efficiency, energy use, and estimated 
operating costs during a representative average use cycle or period of 
use. (42 U.S.C. 6293(b)(3))
    In this final rule, DOE is maintaining the current efficiency 
metrics, EER2, SEER2 and HSPF2, at appendix M1 and is referencing AHRI 
210/240-2024 for measuring the existing metrics. DOE has determined 
that the amendments to appendix M1 would not affect the measured 
efficiency of CAC/HPs or require retesting solely because of DOE's 
adoption of the amendments to the appendix M1 test procedure. At 
appendix M1, DOE is incorporating by reference the following sections 
of the AHRI 210/240-2024: sections 3 (with certain exclusions \16\), 5 
(with one exclusion \17\), 6 (with certain exclusions \18\), 11, and 
12, as well as appendices D, E, G, K, and L.
---------------------------------------------------------------------------

    \16\ DOE is not incorporating by reference the following 
provisions in section 3 of AHRI 210/240-2024 because the terms are 
either defined in appendix M1, or are not needed for the DOE test 
procedure: 3.2.16 (Double-duct System), 3.2.20 (Gross Capacity), 
3.2.46 (Oil Recovery Mode), 3.2.51 (Published Rating), 3.2.63 
(Standard Filter), 3.2.78 (Unitary Air-conditioner), and 3.2.79 
(Unitary Heat Pump).
    \17\ DOE is not incorporating by reference the following 
provision in section 5 of AHRI 210/240-2024 because the term is 
defined in appendix M1: 5.1.6.2 (Outdoor Unit with No Match 
(OUWNM)).
    \18\ DOE is not incorporating by reference the following 
provisions in section 6 of AHRI 210/240-2024 because the provisions 
are either defined in 10 CFR 429.16, or are not needed for the DOE 
test procedure: 6.1.8 (Tested Combinations or Tested Units), 6.2 
(Application Ratings), 6.3 (Publication of Ratings), 6.4 (Ratings), 
and 6.5 (Uncertainty and Variability).
---------------------------------------------------------------------------

    Additionally, DOE is establishing a new test procedure at appendix 
M2 that adopts AHRI 1600-2024, including the new SCORE and SHORE 
metrics.\19\ Use of appendix M2 is not required until the compliance 
date of any amended standards denominated in terms of the new metrics 
for appendix M2, should such standards be adopted. At appendix M2, DOE 
is referencing the following sections of AHRI 1600-2024: sections 3 
(with certain exclusions \20\), 5 (with one exclusion \21\), 6 (with 
certain exclusions \22\), 11, and 12 and appendices D, E, G, K and L.
---------------------------------------------------------------------------

    \19\ As explained in Section III.B.2, DOE will replace EER2 in 
appendix M1 with EER in appendix M2. However, EER will be calculated 
in a manner identical to EER2, and both convey the same full load 
test information.
    \20\ DOE is not incorporating by reference the following 
provisions in section 3 of AHRI 1600-2024 because the terms are 
either defined in appendix M1, or are not needed for the DOE test 
procedure: 3.2.16 (Double-duct System), 3.2.20 (Gross Capacity), 
3.2.45 (Oil Recovery Mode), 3.2.50 (Published Rating), 3.2.63 
(Standard Filter), 3.2.78 (Unitary Air-conditioner), and 3.2.79 
(Unitary Heat Pump).
    \21\ DOE is not incorporating by reference the following 
provision in section 5 of AHRI 1600-2024 because the term is defined 
in appendix M2: 5.1.6.2 (Outdoor Unit with No Match (OUWNM)).
    \22\ DOE is not incorporating by reference the following 
provisions in section 6 of AHRI 1600-2024 D because the provisions 
are either defined in 10 CFR 429.16, or are not needed for the DOE 
test procedure: 6.1.8 (Tested Combinations or Tested Units), 6.2 
(Application Ratings), 6.3 (Publication of Ratings), 6.4 (Ratings), 
and 6.5 (Uncertainty and Variability).
---------------------------------------------------------------------------

    Further, at both appendix M1 and appendix M2, DOE is incorporating 
by reference the following: ANSI/ASHRAE 37-2009, except sections 1 
(Purpose), 2 (Scope), and 4 (Classifications); ANSI/ASHRAE 16-2016 
except sections 1 (Purpose), 2 (Scope), and 4 (Classifications); and 
ANSI/ASHRAE 116-2010 except sections 1 (Purpose), 2 (Scope), 4 
(Classifications), and 7 (Methods of Test).

D. Efficiency Metrics

    As discussed, DOE is updating the current Federal test procedure 
for CAC/HPs at appendix M1 consistent with the most recent draft 
version of the relevant industry consensus test procedure, AHRI 210/
240-2024. DOE is also establishing a new Federal test procedure at 10 
CFR part 430, subpart B, appendix M2, consistent with the new industry 
consensus test procedure, AHRI 1600-2024. Sections III.D.1 and III.D.2 
of this document discuss which metrics are applicable for appendices M1 
and M2, respectively.
1. Metrics Applicable to Appendix M1
    Consistent with the April 2024 NOPR, appendix M1 maintains the 
current energy efficiency metrics (i.e., EER2, SEER2, and HSPF2), and 
includes a new optional metric: the peak load coefficient of 
performance (``COPpeak''), applicable to central heat pumps 
(``CHPs''). The amendments to appendix M1 to align with AHRI 210/240-
2024 maintain the existing energy efficiency metrics, and DOE has 
determined that testing under appendix M1 would be consistent with the 
existing test procedure and there would be no impact on measured 
efficiencies.
2. Metrics Applicable to Appendix M2
    The newly established appendix M2 introduces new integrated cooling 
and integrated heating efficiency metrics, namely SCORE and SHORE, 
respectively. Unlike SEER2 and HSPF2, which are seasonal energy 
efficiency descriptors, SCORE and SHORE are integrated metrics that 
include off mode power, PW,OFF. Hence, appendix M2 will not 
require separate representations for off mode power. Appendix M2 will 
retain the full-load EER metric, with EER evaluated in the same way as 
appendix M1.\23\ Appendix M2 also includes the optional metric 
COPpeak.
---------------------------------------------------------------------------

    \23\ AHRI 1600-2024 replaced the EER2 and COP2 metrics from AHRI 
210/240-2024 with EER and COP. For consistency, appendix M2 will 
follow the nomenclature in AHRI 1600-2024 and will hence use EER as 
the full-load metric, while appendix M1 will use the EER2 metric.
---------------------------------------------------------------------------

E. Near-Term Changes in the CAC/HP Test Procedure

    The following sections discuss issues that affect the CAC/HP test 
procedure in the near term--i.e., they will be required 180 days after 
publication of the final rule. As previously explained, these near-term 
revisions are implemented at appendix M1 via incorporation by reference 
of the relevant industry consensus test procedure, AHRI 210/240-2024. 
DOE has reviewed AHRI 210/240-2024 and has concluded that it satisfies 
the EPCA requirement that test procedures should not be unduly 
burdensome to conduct and should be representative of an average use 
cycle. (42 U.S.C. 6293(b)(3)) These near-term amendments in appendix M1 
do not alter the measured efficiency of CAC/HPs in terms of the current 
cooling and heating test metrics, SEER2 and HSPF2, or the current off 
mode metric, PW,OFF.
    DOE clarifies that while all issues discussed subsequently within 
this section are near-term, they are also part of the long-term CAC/HP 
test procedure--i.e., these revisions are also included in AHRI 1600-
2024, which DOE is incorporating by reference at appendix M2. As such, 
when discussing these near-term changes, DOE makes references to both 
AHRI 210/240-2024 and AHRI 1600-2024.
1. Controls Verification Procedure for Variable-Speed Systems
    Appendix M1 uses a steady-state test concept for variable-speed 
systems where test room conditions are kept within narrow operating 
tolerances for each test point, and the CAC/HP system is manually 
controlled to operate at a fixed specified compressor speed and airflow 
rate for each test point. As part of the previous rulemaking, several 
stakeholders encouraged DOE to review ways to improve the 
representativeness of the test procedures for CAC/HPs (especially 
variable-speed systems), particularly to consider test procedures where 
the unit operates under its own native controls in responding to 
conditioning loads (i.e., load-based testing).\24\
---------------------------------------------------------------------------

    \24\ A load-based test method differs from the steady-state test 
method currently used in DOE test procedures for air-conditioning 
and heat pump equipment. In a steady-state test method, the indoor 
room is maintained at a constant temperature throughout the test. In 
this type of test, any variable-speed or variable-position 
components of air conditioners and heat pumps are set in a fixed 
position, which is typically specified by the manufacturer. In 
contrast, a load-based test has the conditioning load applied to the 
indoor room using a load profile that approximates how the load 
varies for units installed in the field. In this type of test, an 
air-conditioning system or heat pump is allowed to automatically 
determine and vary its control settings in response to the imposed 
conditioning loads rather than relying on manufacturer-specified 
settings.

---------------------------------------------------------------------------

[[Page 1232]]

    To review this topic in detail as part of the current rulemaking, 
in an RFI published on January 24, 2023, (the ``January 2023 RFI''), 
DOE requested comments, information, and data pertaining to the 
consideration of load-based testing methodologies under development by 
various organizations and whether certain aspects of these 
methodologies might be adopted into the DOE test procedure. 88 FR 4091, 
4098-4101.
    In the April 2024 NOPR, based on review of the stakeholder comments 
received in response to the January 2023 RFI--specifically, that it has 
not yet been conclusively demonstrated that load-based testing methods 
have sufficient repeatability and reproducibility to be the basis of 
direct measurement of system performance--DOE tentatively concluded 
that use for direct measurement of performance for regulatory purposes 
would not be suitable at this time. 89 FR 24206, 24220. Instead, DOE 
tentatively concluded that it would be appropriate to continue to allow 
regulatory tests to use fixed-speed settings for testing variable-speed 
systems, while developing a controls verification procedure (``CVP'') 
that could be used for audit, assessment, and enforcement testing to 
ensure that the fixed-speed settings are representative of native 
(unfixed) control, in which the control system may vary compressor 
speed and/or indoor airflow. Id.
    DOE noted that AHRI and other relevant stakeholders, including DOE, 
participated in the development of revised AHRI test standards to 
address several issues raised in the January 2023 RFI, including the 
representativeness of fixed-speed testing for variable-speed systems. 
89 FR 24206, 24220. From these discussions on the revised AHRI test 
standards, consensus was developed on using a CVP approach. Id. In 
section III.F.1.e of the April 2024 NOPR, DOE provided a summary of the 
CVP approach in Appendix I of AHRI 210/240-202X Draft and AHRI 1600-
202X Draft. 89 FR 24206, 24220-24222.
    DOE acknowledged that the CVP approach outlined in appendix I of 
the relevant AHRI drafts represented industry consensus regarding: (1) 
the verification of compliance of systems with the variable capacity 
system definition, and (2) verification of the consistency of fixed-
speed settings of compressor and indoor fans with native control 
operation as part of enforcement. 89 FR 24206, 24222. DOE considered 
that the CVP approach presented a more representative test procedure 
for variable-speed systems operating in the field, because it provided 
a tool to verify that the fixed compressor speed settings and indoor 
air fan settings used in regulatory tests are representative of native 
control operation as the unit operates to maintain the thermostat set 
point, i.e., indoor dry-bulb temperature. Id. For these reasons, DOE 
proposed to incorporate by reference appendix I of AHRI 210/240-202X 
Draft to support enforcement associated with testing conducted in 
accordance with appendix M1, and to incorporate by reference appendix I 
of AHRI 1600-202X Draft to support enforcement associated with testing 
conducted in accordance with appendix M2. Id.
    In response to DOE's proposal, several stakeholders, namely Lennox, 
the CA IOUs, Rheem, Daikin, GE Appliances, and Carrier, generally 
showed support for DOE's proposal on implementing the CVP approach for 
certification of variable-speed products. (Lennox, No. 24 at p. 2; CA 
IOUs, No. 32 at p. 2; Rheem, No. 34 at p. 5; Daikin, No. 36 at p. 3; GE 
Appliances, No. 37 at p. 4; Carrier, No. 29 at p. 5)
    The Joint Advocates commented that even though it is not 
appropriate to adopt load-based testing for measuring the direct 
regulatory test performance of CAC/HPs due to insufficient information 
on repeatability and reproducibility of load-based testing methods, DOE 
should consider adopting them as an integral part of the test procedure 
in a future update to the CAC/HP test procedure. (Joint Advocates, No. 
30 at pp. 3-4) Further, the Joint Advocates commented that test data 
that will better inform repeatability and reproducibility of load-based 
tests will be coming out in the near future. (Id.) The Joint Advocates 
expressed concern that since the CVP is only an enforcement provision, 
manufacturers are not required to conduct it while rating their 
product, and hence, adopting some version of load-based testing will 
ensure that all certified ratings are more representative of unit 
performance in the field. (Id.)
    In response to the Joint Advocates' comment, DOE reiterates that it 
explored the potential of adopting a load-based method for direct 
measurement of performance in the April 2024 NOPR. However, as 
discussed in the April 2024 NOPR, the consensus of affected 
stakeholders was to adopt a CVP approach instead of a wholesale load-
based method test procedure. 89 FR 24206, 24222. DOE is not aware of 
additional information, such as new load-based test data, available for 
review to assess the feasibility of adopting load-based testing as a 
mandatory part of the CAC/HP test procedure. Even though the CVP is 
primarily intended for use by DOE for assessment and enforcement 
purposes, it is expected that manufacturers will preemptively utilize 
the CVP to evaluate the fixed-speed settings used for certification 
tests of their variable-speed products to ensure consistency with 
native-control operation.
    AHRI 210/240-2024 and AHRI 1600-2024, the industry standards DOE is 
referencing in this final rule, finalized the relevant test method for 
the CVP at appendix I without any substantial change as compared to 
their corresponding drafts. Therefore, consistent with the April 2024 
NOPR, DOE is incorporating by reference appendix I of AHRI 210/240-2024 
to support enforcement associated with testing conducted in accordance 
with appendix M1, and to incorporate by reference appendix I of AHRI 
1600-2024 to support enforcement associated with testing conducted in 
accordance with appendix M2. The enforcement provisions are discussed 
in more detail in section III.I.2 of this document.
2. Low-Temperature Heating Performance
    In the April 2024 NOPR, DOE proposed to incorporate by reference 
AHRI 210/240-202X and AHRI 1600-202X Drafts and adopt several test 
procedure provisions that pertained to low-temperature heating 
performance. 89 FR 24206, 24222-24225. Specifically, DOE proposed to 
(1) reference the definition of ``cold climate heat pump'' (``CCHP'') 
contained in the AHRI drafts, (2) reference the requirement for 
products certified as a CCHP to conduct the H4 heating test (either the 
H4, H4Full, or H4Boost heating test, as 
applicable), (3) retain the current size-for-cooling approach, and (4) 
include COPpeak as an optional representation for combined 
heat pump and electric resistance heat efficiency at 5 [deg]F outdoor 
temperature for CHPs, as outlined in appendix K of AHRI 210/240-202X 
and AHRI 1600-202X Drafts,\25\ at appendix M1 and appendix M2, 
respectively.
---------------------------------------------------------------------------

    \25\ In several instances of the April 2024 NOPR, DOE 
incorrectly referred to appendix L of the respective AHRI 210/240-
202X and AHRI 1600-202X Drafts as the appendices regarding 
COPpeak. (See 89 FR 24206, 24225). These were 
typographical errors, since the appendices regarding 
COPpeak are at appendix K of the respective AHRI 210/240-
202X and AHRI 1600-202X Drafts.

---------------------------------------------------------------------------

[[Page 1233]]

    DOE did not receive any comments regarding the aforementioned 
proposals in the April 2024 NOPR. AHRI 210/240-2024 and AHRI 1600-2024, 
the final versions of the draft AHRI standards, finalized the same low-
temperature heating performance provisions without change. Therefore, 
consistent with the April 2024 NOPR proposal, DOE is incorporating by 
reference AHRI 210/240-2024 and AHRI 1600-2024 and adopting the low-
temperature heating performance provisions discussed in the 
aforementioned paragraphs.
3. Cut-Out and Cut-In Temperature Verification
    Appendix J of AHRI 210/240-202X Draft and also of AHRI 1600-202X 
Draft includes a test applicable to all CHPs to determine cut-out and 
cut-in temperatures (i.e., Toff and Ton 
respectively).\26\ In the April 2024 NOPR, DOE proposed that during 
assessment and enforcement testing of CHPs, DOE may verify the cut-out 
and cut-in temperatures using the test specified in appendix J of AHRI 
210/240-202X Draft, when conducting assessment and enforcement testing 
associated with appendix M1, and the test specified in appendix J of 
AHRI 1600-202X Draft, when conducting assessment and enforcement 
testing associated with appendix M2. The proposal indicated that, if 
conducting the appendix J cut-out/cut-in verification, the tested 
values determined for these temperatures would be used as the 
Toff and Ton values for the unit. 89 FR 24206, 
24226.
---------------------------------------------------------------------------

    \26\ In several instances of the April 2024 NOPR, DOE 
incorrectly referred to appendix K of the respective AHRI 210/240-
202X and AHRI 1600-202X Drafts as the appendices regarding cut-out 
and cut-in temperature verification. (See 89 FR 24206, 24226 and 89 
FR 24206, 24243). These were typographical errors, since the 
appendices regarding cut-out and cut-in temperature verification are 
at appendix J of the respective AHRI 210/240-202X and AHRI 1600-202X 
Drafts.
---------------------------------------------------------------------------

    AHRI 210/240-2024 and AHRI 1600-2024, the industry standards DOE is 
referencing in this final rule, finalized the relevant test method for 
determining cut-out and cut-in temperatures at appendix J without any 
substantial change as compared to their respective drafts. Therefore, 
consistent with the April 2024 NOPR, DOE is incorporating by reference 
appendix J of AHRI 210/240-2024 and AHRI 1600-2024 at appendix M1 and 
appendix M2, respectively.
    As further discussed in section III.I.1 of this document, DOE may 
verify certified cut-out and cut-in temperatures using the test methods 
in appendix J of the relevant AHRI drafts for the purposes of 
assessment and enforcement testing.
4. Low-Static Single-Split Blower-Coil System Definition and Testing 
Provisions
    Section 3.1.4.1.1 of appendix M1 defines the minimum external 
static pressure (``ESP'') for ducted blower-coil systems in table 4. 
For conventional blower-coil systems (i.e., all CAC/HPs that are not 
classified as ceiling-mount, wall-mount, mobile home, low-static, mid-
static, small-duct high-velocity (``SDHV''), or space-constrained), the 
minimum ESP is specified as 0.5 inches of water column (``in. wc.''). 
The definition for low-static blower-coil systems includes only multi-
split and multi-head mini-split systems--it does not include single-
split systems.
    AHRI 210/240-202X Draft and AHRI 1600-202X Draft include a new 
definition specific for low-static single-split blower-coil systems, as 
shown below.
    ``Low-static single-split blower-coil system'' means a ducted 
single-split system air conditioner or heat pump for which all of the 
following apply:
    (1) The Outdoor Unit has a Specified cooling capacity less than or 
equal to 24,000 Btu/h;
    (2) If the Outdoor Unit is a heat pump or a variable capacity air 
conditioner, it is separately Specified with a blower-coil indoor unit 
tested with a minimum 0.5 in H2O ESP, otherwise it is separately 
Specified with a coil-only indoor unit; and
    (3) The Indoor Unit is marketed for and produces a maximum ESP less 
than 0.5 in H2O when operated at the Specified cooling full-load 
airflow not exceeding 400 scfm per Specified ton of cooling.
    Both drafts also include provisions requiring low-static single-
split blower-coil systems to be tested at their specified airflow (not 
to exceed 400 standardized cubic feet per minute (``scfm'') per 
specified ton of cooling capacity) at their maximum airflow setting. If 
the ESP achieved at the specified airflow is less than 0.1 in. wc., the 
provisions require adjustment of the airflow measurement apparatus fan 
to reduce airflow and increase ESP until a minimum of 0.1 in. wc. is 
achieved.
    In the April 2024 NOPR, DOE proposed to incorporate by reference 
the new definition of low-static single-split blower-coil system and 
associated testing provisions, which would include single-split systems 
that cannot accommodate the 0.5 in. wc. required for testing single-
split blower-coil systems in accordance with the current DOE test 
procedure in appendix M1. 89 FR 24206, 24227.
    DOE did not receive any comments regarding the aforementioned 
proposals in the April 2024 NOPR. AHRI 210/240-2024 and AHRI 1600-2024 
finalized the definition and testing provisions for low-static single-
split blower-coil systems without substantial change as compared with 
their respective drafts. Therefore, consistent with the April 2024 NOPR 
proposals, DOE is incorporating by reference AHRI 210/240-2024 and AHRI 
1600-2024, and adopting the definition and testing provisions for low-
static single-split blower-coil systems.
    In advance of adopting these changes, multiple manufacturers, 
including Samsung HVAC America LLC (``Samsung''),\27\ Mitsubishi,\28\ 
and Hisense (Guangdong) Air Conditioning Co. Ltd. (``Hisense''),\29\ 
petitioned DOE for test procedure waivers pertaining to low-static 
single-split blower-coil systems. All petitions asserted nearly 
identical circumstances and model limitations--that it was impossible 
to test certain basic models according to appendix M1 because the 
models could not operate at the conventional minimum ESP requirement of 
0.5 in. wc. found in table 4 of appendix M1. Subsequently, 
manufacturers could not certify compliance for or sell these products.
---------------------------------------------------------------------------

    \27\ See Samsung's petition at www.regulations.gov/docket/EERE-2023-BT-WAV-0010.
    \28\ See Mitsubishi's petition at www.regulations.gov/docket/EERE-2023-BT-WAV-0015.
    \29\ See Hisense's petition at www.regulations.gov/docket/EERE-2023-BT-WAV-0011.
---------------------------------------------------------------------------

    On June 5, 2023, DOE published a notification of petition for 
waiver and grant of an interim waiver that permits Samsung to use an 
alternative test procedure for the basic models subject to its 
petition. 88 FR 36558. The alternative test procedure allows Samsung to 
test its basic models that are designed for low-static, short-duct 
applications at 0.1 in. wc. ESP and to make proportional adjustments to 
fan power and capacity such that the results are equivalent to 
performance measured at 0.5 in. wc. ESP. 88 FR 36558, 36561-36563. DOE 
initially determined that this alternate test procedure was appropriate 
and allowed for the accurate measurement of the energy efficiency of 
the specified basic models, while alleviating the testing problems 
cited in implementing the DOE test procedure for the models. Id.
    In the April 2024 NOPR, DOE noted that, should the new definition 
of low-

[[Page 1234]]

static single-split blower-coil system and the associated testing 
provisions be adopted, DOE would terminate Samsung's interim waiver 
pending final determination. 89 FR 24206, 24227. The interim waiver was 
granted with the understanding that it was impossible to test the 
manufacturer's specific basic models according to the prescribed test 
procedures in appendix M1. Given that DOE is adopting provisions for 
low-static single-split blower-coil systems, DOE concludes that this 
alternate test procedure is no longer necessary. Therefore, DOE is 
terminating the aforementioned waiver for Samsung. DOE notes that the 
ratings for the subject Samsung basic models may change when moving to 
the amended appendix M1 test procedure outlined in this final rule.
    DOE has not published a notification of petition for waiver or 
granted interim waivers for either the Mitsubishi or Hisense petitions. 
However, for the same reasons that DOE is terminating Samsung's 
aforementioned waiver, DOE concludes that an alternate test procedure 
is no longer necessary. DOE considers the petitions submitted by 
Mitsubishi and Hisense to be addressed sufficiently by the low-static 
single-split blower-coil system definition and testing provisions 
adopted in this final rule.
5. Mandatory Constant Circulation Systems
    Currently, nearly all CAC/HP products are designed with R-410A as 
the refrigerant. However, under global warming potential (``GWP'') 
restrictions enacted by an Environmental Protection Agency (``EPA'') 
final rule published on October 24, 2023 (``October 2023 EPA final 
rule''), the use of R-410A is scheduled to be phased out for CAC/HP 
products.\30\ 88 FR 73098. The EPA Significant New Alternatives Policy 
(``SNAP'') Program evaluates and regulates substitutes for ozone-
depleting chemicals (such as CAC/HP refrigerants) that are being phased 
out under the stratospheric ozone protection provisions of the Clean 
Air Act. (42 U.S.C. 7401 et seq.) \31\ Of interest to CAC/HPs, the EPA 
SNAP Program's list of viable substitutes \32\ includes a group of 
refrigerants classified as A2L refrigerants. While these refrigerants 
have GWP levels meeting the requirements of the October 2023 EPA Final 
Rule, they face stricter safety requirements than R-410A due to the 
moderate flammability associated with their ``2L'' ASHRAE safety 
classification.\33\ Many of the safety requirements specifically 
address mitigation of ignition risk in case of refrigerant leakage. One 
mitigation option for refrigerant leakage is air circulation, which can 
be initiated when a leak is detected, or the system can use ``constant 
circulation,'' running the fan, typically at a reduced speed, at all 
times. This latter approach has energy use implications, which are 
addressed in the AHRI 210/240 and AHRI 1600 standards.\34\
---------------------------------------------------------------------------

    \30\ EPA published an interim final rule on December 26, 2023 
(``EPA Technology Transition Interim Final Rule'') that allows 1 
additional year, until January 1, 2026, solely for the installation 
of new CAC/HPs using components manufactured or imported prior to 
January 1, 2025. 88 FR 88825.
    \31\ Additional information regarding EPA's SNAP Program is 
available online at www.epa.gov/ozone/snap/.
    \32\ A list of EPA SNAP Program-approved refrigerant substitutes 
is available at www.epa.gov/snap/substitutes-residential-and-light-commercial-air-conditioning-and-heat-pumps.
    \33\ ASHRAE assigns safety classification to refrigerants based 
on toxicity and flammability data. The capital letter designates a 
toxicity class based on allowable exposure, and the numeral denotes 
flammability. For toxicity, class A denotes refrigerants of lower 
toxicity, and class B denotes refrigerants of higher toxicity. For 
flammability, class 1 denotes refrigerants that do not propagate a 
flame when tested as per the standard; classes 2 and 2L denote 
refrigerants of lower flammability; and class 3 denotes highly 
flammable refrigerants (such as hydrocarbons).
    \34\ DOE is aware that a refrigerant leakage detection system 
may also draw power, which would also be addressed in the AHRI 210/
240 and AHRI 1600 test standards. However it is DOE's understanding 
that the impact of this power is much less than operation of the fan 
in constant circulation mode.
---------------------------------------------------------------------------

    AHRI 210/240-202X Draft and AHRI 1600-202X Draft include a new 
definition for ``mandatory constant circulation system'' (``MCCS''). 
The updated industry standard drafts also include testing provisions 
for such systems, specifically requiring that CAC/HPs meeting the 
mandatory constant circulation system definition not use the default 
cooling and heating degradation coefficients, but rather evaluate these 
degradation coefficients using the respective cyclic tests specified by 
table 7 of AHRI 210/240-202X Draft and AHRI 1600-202X Draft, conducted 
in accordance with section E12 of appendix E of AHRI 210/240-202X Draft 
and AHRI 1600-202X Draft. In the April 2024 NOPR, DOE proposed to 
incorporate by reference the new definition of MCCS and the 
aforementioned testing provisions outlined in AHRI 210/240-202X Draft 
and AHRI 1600-202X Draft, at appendix M1 and appendix M2, respectively. 
89 FR 24206, 24228.
    In response to DOE's proposal, Carrier expressed support for the 
MCCS testing approach, but it commented that there is ambiguity 
regarding the specific products to which the MCCS testing approach 
applies. (Carrier, No. 29 at pp. 2-3) Carrier stated that for a CAC/HP 
system with a charge quantity between m1 and m2,\35\ the room size in 
which the UL 60335-2-40 4th edition refrigerant safety standard allows 
the system to be installed (or the effective volume into which 
refrigerant would be dispersed in case of leakage) is limited. Further, 
this limitation can be stricter if the system does not employ air 
circulation, either continuously or initiated by a refrigerant leak 
detection system (``LDS''). (Id.) Carrier requested that DOE provide 
further specificity on the testing approach for products that might 
require air circulation as mitigation in some installations but not 
necessarily all installations. (Id.) Carrier recommended that DOE 
require all systems with a charge level greater than m1 and less than 
or equal to m2 that do not contain an LDS be tested as an MCCS since 
how and where these products are installed in the field are outside the 
manufacturer's control (besides a label specifying the required area). 
(Id.)
---------------------------------------------------------------------------

    \35\ UL 60335-2-40 fourth edition defines charge quantities m1 
and m2 based on the type of refrigerant.
---------------------------------------------------------------------------

    In a rebuttal, Daikin opposed Carrier's aforementioned 
recommendation, for several reasons. (Daikin, No. 40 at p. 1) First, 
Daikin commented that UL 60335-2-40 4th edition is clear in its 
requirements for information that must be provided in installation 
instructions, including instructions regarding how to install the 
product in accordance with refrigerant safety codes, including how to 
meet the minimum floor area requirements. (Id.) Daikin specifically 
pointed to Annex DD of UL 60335-2-40 4th edition, which specifies that 
an original equipment manufacturer (``OEM'') must include details of 
minimum installation height, minimum floor area, and other appropriate 
information in installation instructions to ensure safety requirements 
are met. (Id.) Daikin also commented that CAC/HPs using A2L 
refrigerant, in addition to providing information in installation 
instructions, must have adequate warning labels (per Clause 7 of UL 
60335-2-40 4th edition, Annex 101.DVF of UL 60335-2-40 4th edition, and 
EPA SNAP Rule 25), such that the installer will be well aware the 
product being installed needs special attention. (Id.)
    Second, Daikin commented that the minimum floor area required by 
ASHRAE 15.2 (with which UL 60335-2-40 requires compliance), for some 
situations, does not depend on whether

[[Page 1235]]

the system employs circulation (whether continuous or LDS initiated) to 
meet mitigation requirements. (Daikin, No. 40 at p. 2)
    Third, Daikin commented that, if a manufacturer chooses to use 
continuous circulation airflow as the method of leak mitigation, the 
manufacturer must conduct additional safety verification of that 
function, per Annex GG of UL 60335-2-40 4th edition (specifically, 
Clause GG.2.2.2DV). (Daikin, No. 40 at pp. 2-3) Annex GG of UL 60335-2-
40 4th edition states that a product using continuous circulation shall 
(1) run the indoor fan continuously, except for short periods of 
maintenance and service; (2) detect or monitor continuously if the 
airflow rate drops below a specific level (Qmin); and (3) if 
the airflow drops below the specified level, provide an output signal 
that airflow is reduced and disable compressor operation unless the 
compressor operation reduces the leak rate or the total amount of 
refrigerant released to the indoor space. Consequently, Daikin 
commented that, if the manufacturer chooses to rely on continuous 
circulation as the mitigation method, the OSHA-certified Nationally 
Recognized Testing Laboratory (``NRTL'') that certifies the product to 
meet the safety standard UL 60335-2-40 must check by inspection that 
the manufacturer runs the fan continuously. (Id.)
    Fourth, Daikin commented on the DOE test procedure emphasis on 
installation instructions. (Daikin, No. 40 at p. 3) The DOE test 
procedure requirement to follow the OEM installation instructions when 
installing a system for testing is based on the premise that the 
installation instructions provide a setup representative of field 
installation. Thus, Daikin asserted it would be logical for DOE to be 
consistent and also assume that the installing contractor would follow 
requirements related to refrigerant safety that are laid out in 
installation instructions. (Id.)
    In response to the Carrier and Daikin comments, it is DOE's 
understanding (as noted in Daikin's comment) that use of constant 
circulation as the method of refrigerant leakage risk mitigation 
requires that the CAC/HP product must be inherently designed with this 
feature--a contractor cannot be in compliance with UL 60335-2-40 4th 
edition requirements if the feature is selected in the field for a 
system that does not inherently already have it. Specifically, an NRTL 
must certify upon inspection that a product using constant circulation 
for safety code compliance indeed runs its indoor fan continuously. 
Thus, the circumstances ``outside the manufacturer's control'' 
involving installation by a contractor using constant circulation as 
the means of mitigation of systems without LDS and without MCCS that 
Carrier mentioned in its comment are violations of refrigerant safety 
codes. While such violations may occur in the future, DOE concludes 
that the seriousness of the potential consequences would make them 
infrequent, i.e., such circumstances could not be considered 
representative of the installation of such systems. Therefore, DOE 
determines that, for testing according to the DOE test procedure, it is 
not appropriate to require testing using constant circulation for 
products with charge between m1 and m2 that don't have an LDS and are 
not inherently an MCCS. However, any product using constant circulation 
to comply with refrigerant safety codes that would meet the MCCS 
definition in AHRI 210/240-202X Draft and AHRI 1600-202X Draft could be 
verified to have this status by powering up the unit, and consequently 
will be required to test as an MCCS.
    AHRI 210/240-2024 and AHRI 1600-2024 finalized the definition and 
testing provisions for MCCS without substantial change. DOE has 
determined that the definition and approach included in the finalized 
versions provide a more representative measure of CAC/HP efficiency for 
systems utilizing mandatory constant circulation as a means of 
refrigerant leakage mitigation. Therefore, consistent with the April 
2024 NOPR proposals, DOE is incorporating by reference AHRI 210/240-
2024 and AHRI 1600-2024 and adopting the definition and testing 
provisions for MCCS.
    Daikin noted in its comment that the certification aspects of the 
MCCS test procedure changes were not included in the April 2024 NOPR. 
(Daikin, No. 40 at p. 3) Daikin recommended that DOE include as 
mandatory certification a declaration from the manufacturer regarding 
whether the CAC/HP product relies upon mandatory continuous circulation 
or not. (Id.) Further, Daikin suggested that whether a product uses 
continuous circulation or not could be validated by operation of the 
product when it is powered up, as well as validated by the safety 
agency (i.e., NRTL) certification report. (Id.)
    In response to Daikin's recommendation, DOE notes that it will 
consider certification requirements for CAC/HPs, including a 
requirement to certify whether the CAC/HP product relies upon mandatory 
constant circulation or not, in a separate rulemaking. However, DOE may 
validate whether a system utilizes constant circulation when powered up 
for the purposes of assessment or enforcement testing.
6. Dual-Fuel Heat Pumps
    Heat pumps generally have reduced capacity and perform less 
efficiently at low ambient outdoor temperatures than they do at 
moderate ambient outdoor temperatures. Most heat pumps require some 
form of auxiliary heat when outdoor temperature is low to satisfy 
building load in excess of heat pump capacity. DOE is aware of HPs that 
combine the operation of a conventional electric HP with back-up heat 
provided by fuel, such as a gas fuel-fired furnace or boiler. These are 
referred to as ``dual-fuel'' systems or hybrid heat pumps (``HHPs'') 
and provide an alternative to heat pumps specifically designed to 
perform in cold climates (i.e., cold climate heat pumps). Dual-fuel 
systems rely on heat pump operation at milder ambient temperatures, but 
switch to the back-up heating source at low ambient temperatures.
    The AHRI 210/240-202X Draft and AHRI 1600-202X Draft included a new 
definition for dual-fuel heat pump systems. Additionally, the two AHRI 
drafts introduced a new seasonal efficiency metric, Dual Fuel 
Utilization Efficiency (``DFUE''), meant to capture the heating 
efficiency of such dual-fuel heat pump systems. Calculation of DFUE 
according to the draft standards is optional, requires no additional 
testing, and is outlined in appendix L of both standards.
    In the April 2024 NOPR, DOE tentatively determined that while the 
definition and optional test approach included in the draft industry 
standards may provide a representative test approach for dual-fuel heat 
pump systems, DOE was at that time continuing to evaluate whether to 
include such provisions in its CAC/HP test procedures. 89 FR 24206, 
24229. Therefore, DOE proposed to not incorporate by reference the new 
definition of dual-fuel heat pump and the optional seasonal efficiency 
metric, DFUE, outlined in the AHRI 210/240-202X and AHRI 1600-202X 
Drafts. Id.
    AHRI 210/240-2024 and AHRI 1600-2024 finalized the definition and 
optional seasonal efficiency metric, DFUE, for dual-fuel heat pump 
without substantial change. Based on DOE's continued evaluation of the 
dual-fuel provisions in the two AHRI drafts, DOE has concluded that 
such provisions are not necessary in the CAC/HP test procedures. 
Therefore, DOE is not incorporating by reference the new definition of 
dual-fuel heat pump and

[[Page 1236]]

the optional seasonal efficiency metric, DFUE, outlined in the AHRI 
210/240-2024 and AHRI 1600-2024. However, DOE recognizes that 
representations of dual-fuel heat pump performance may be useful to 
consumers. Therefore, while DOE is not proposing provisions for dual-
fuel heat pumps, DOE would allow manufacturers to make optional 
representations of dual-fuel heat pump performance consistent with 
available AHRI industry test standards.
    DOE notes that since dual-fuel heat pump systems are comprised of 
two covered products currently subject to energy conservations 
standards (i.e., a heat pump and a furnace), DOE would continue to 
require reporting of the relevant CAC/HP and consumer furnace heating 
metrics--EER2, SEER2, HSPF2, EER, SCORE and SHORE for CAC/HP, and AFUE 
for consumer furnaces; regardless of whether a manufacturer chooses to 
rate their dual-fuel heat pumps with the DFUE metric. DOE also notes 
that the current representation requirements at 10 CFR 429.16 require 
representation of every individual heat pump combination distributed in 
commerce. As such, installing an outdoor HP unit and an indoor coil 
with an existing furnace (or other air mover) that is not being 
replaced would constitute distribution in commerce of a coil-only heat 
pump combination for which DOE requires a coil-only representation.
7. Rating Individual Components of Split Systems
(a) Background
    DOE's test procedure in appendix M1 and its rating and 
certification requirements for central air conditioners and heat pumps 
in 10 CFR 429.16 have provisions that apply based on the configurations 
in which these products are distributed in commerce. This includes 
provisions for outdoor units of a split system that are not distributed 
in commerce with any indoor units, which DOE's regulations refer to as 
an outdoor unit with no match (``OUWNM'').
    Specifically, 10 CFR 429.16(b)(2) requires that the ratings for 
basic models of split-system central air conditioners or heat pumps 
distributed in commerce as an OUWNM be based on the testing of a model 
of coil-only indoor unit meeting the requirements of section 2.2e of 
appendix M1. Section 2.2.e of appendix M1 requires that an OUWNM be 
tested using a coil-only indoor unit with a single cooling air volume 
rate whose coil has round tubes of outer diameter no less than 0.375 
inches, and normalized gross indoor fin surface (``NGIFS,'' gross 
indoor fin surface divided by the measured cooling capacity) no greater 
than 1.0 square inch per British thermal unit per hour (sq in/Btu/hr). 
(10 CFR 429.16 (b)(2)(i) and appendix M1, section 2.2.e) These 
provisions were introduced in a final rule regarding CAC/HP test 
procedures published on June 8, 2016 (``June 2016 Final Rule''), to 
address outdoor-unit-only replacements of old R-22 outdoor units. 81 FR 
36992, 37008-37012.
    Effective January 1, 2010, EPA banned sales and distribution of 
CAC/HPs designed to use R-22, a hydrochlorofluorocarbon (``HCFC'') 
refrigerant that causes ozone depletion. 74 FR 66450 (Dec. 15, 2009). 
However, EPA continued to allow sale and distribution of ``components'' 
of CAC/HP systems for repair purposes, such as outdoor units. Id. at 74 
FR 66452. In the June 2016 Final Rule, DOE introduced the testing 
provisions for OUWNMs to ensure that performance ratings for such 
installations would be representative of the replacement of outdoor 
units originally designed for R-22 and using the original indoor units. 
See 81 FR 36992, 37008-37011.
    In a final rule published on October 24, 2023 (``October 2023 EPA 
final rule''), pursuant to provisions of the American Innovation and 
Manufacturing Act (``AIM Act''), enacted on December 17, 2020 (42 
U.S.C. 7675), EPA restricted the installation of residential and light 
commercial systems that are designed for hydrofluorocarbon (``HFC'') 
refrigerants having a GWP greater than 700, starting January 1, 2025. 
88 FR 73098. On December 26, 2023, EPA published an amendment to the 
October 2023 EPA Final Rule that extended the installation deadline to 
January 1, 2026, as long as the ``specified components'' being 
installed were manufactured or imported prior to January 1, 2025 
(``December 2023 EPA interim final rule''). 88 FR 88825.
    Split-system CAC/HPs are included in the scope of residential and 
light commercial systems As such, new split-system CAC/HPs designed for 
use with R-410A and sold as a combination of an outdoor and indoor unit 
would be banned for installation, per the October 2023 EPA Final Rule. 
However, EPA provides an exemption, permitting the sales of specified 
components, to allow consumers to service and repair existing systems 
that are over the GWP limits defined in the October 2023 EPA Final 
Rule, provided the specified components are used only to service 
existing systems and are subject to labeling and reporting 
requirements. 88 FR 73098, 73124-73125. This provides an exemption for 
individual specified components of R-410A based split-system CAC/HPs to 
be sold as replacements, including condensing units and evaporator 
units, similar to the component exemption adopted by the EPA when R-22 
was phased out. 74 FR 66450, 66459-66460.
(b) NOPR Proposal
    In the April 2024 NOPR, DOE noted that while the current OUWNM 
provisions were precipitated by EPA's ruling on R-22 units, DOE's 
intention was to apply them more broadly to any case where an outdoor 
unit is sold without an indoor unit. 89 FR 24206, 24230. DOE noted that 
the current OUWNM provisions apply for any outdoor units that are 
distributed in commerce without an indoor matching pair, regardless of 
the refrigerant the outdoor unit employs. Id. DOE clarified that per 
the October 2023 EPA Final Rule, any outdoor unit designed for R-410A 
or any banned refrigerant as per EPA regulations, when distributed in 
commerce without an indoor unit on or after January 1, 2026, would be 
deemed an outdoor unit with no match. Id. DOE further noted that, 
similar to EPA requirements for the R-22 ban, EPA is allowing such an 
outdoor unit to be installed as a replacement specified component for 
an existing system but not to be installed with indoor units for 
installation as a complete split CAC/HP system. Id.
    DOE noted that appendix M1 currently does not explicitly define 
outdoor units with no match and that while AHRI 210/240-202X Draft and 
AHRI 1600-202X Draft define outdoor units with no match, the definition 
applies explicitly only to R-22 replacement outdoor units and outdoor 
units using refrigerants with properties similar to R-22. Id. Because 
the definition of outdoor unit with no match in AHRI 210/240-202X Draft 
and AHRI 1600-202X Draft is specifically focused on R-22 outdoor units, 
DOE proposed not to incorporate the definition by reference, and 
instead proposed a clarifying definition that is consistent with DOE's 
intention in the June 2016 Final Rule. Id.
    DOE proposed the following definition for OUWNM in the April 2024 
NOPR for appendix M1:
    Outdoor Unit with No Match (OUWNM). An Outdoor Unit that is not 
distributed in commerce with any indoor units, and that meets any of 
the following criteria:
    (a) Is designed for use with a refrigerant that makes the unit 
banned for installation when paired with an Indoor Unit as a system, 
according to EPA regulations,

[[Page 1237]]

    (b) Is designed for use with a refrigerant that has a 95 [deg]F 
midpoint saturation absolute pressure that is  18 percent 
of the 95 [deg]F saturation absolute pressure for R-22, or
    (c) Is shipped without a specified refrigerant from the point of 
manufacture or is shipped such that more than 2 pounds of refrigerant 
are required to meet the charge per section 5.1.8 of AHRI 210/240-202X 
Draft. This shall not apply if either (a) the factory charge is equal 
to or greater than 70 percent of the outdoor unit internal volume times 
the liquid density of refrigerant at 95 [deg]F, or (b) an A2L 
refrigerant is approved for use and listed in the certification report.
    DOE noted that the proposed definition of OUWNM for appendix M2 is 
the same as that for appendix M1, except that the reference in part (c) 
of the definition is to section 5.1.8 of AHRI 1600-202X Draft. Id.
    DOE tentatively concluded that the proposed definition would 
further help clarify that the existing test procedure and rating 
requirements for outdoor units with no match are applicable to R-410A-
based systems and any other refrigerants banned by EPA regulations from 
January 1, 2026, as they have been previously, for R-22 and any other 
ozone-depleting refrigerants. Id. As proposed, the definition would 
apply to all types of outdoor units (i.e., heat pump, air conditioner, 
single-speed, two-speed, variable-speed, etc.) and outdoor units with 
no match would continue to be tested with an indoor coil having a 
nominal tube diameter of 0.375 in and an NGIFS of 1.0 or less (as 
determined in section 5.1.6.3 of AHRI 210/240-202X Draft and AHRI 1600-
202X Draft). Id. DOE clarified that the determination of represented 
values, alternative efficiency determination method (``AEDM'') 
requirements, combinations selected for testing, and certification 
report requirements applicable to outdoor units with no match would 
remain the same as those specified in table 1 to paragraph (a)(1), 
paragraph (c)(2), table 2 to paragraph (b)(2)(i), and paragraph (e)(3), 
respectively, in 10 CFR 429.16. Id. DOE noted that existing outdoor 
models currently distributed in commerce as part of a split-system 
basic model that transition to a replacement outdoor unit only would 
need to be tested, rated, and recertified under the provisions in 10 
CFR 429.16 for an outdoor unit with no match. Id. DOE noted that the 
basic model number would need to change to reflect that the outdoor 
unit is no longer part of a combination as previously certified, but 
rather as an outdoor unit with no match; however, the outdoor unit 
model could still be assigned the same individual model number. Id.
(c) Interaction With EPA Regulations
    In response to its April 2024 NOPR, DOE received comments from 
stakeholders on a variety of issues related to compliance with DOE's 
regulations in the context of the October 2023 EPA Final Rule. These 
specific comments are addressed in the next section, but to ensure 
clarity this section first summarizes the key elements of compliance 
with DOE testing, rating, and certification requirements for these 
products during the period of implementation of the EPA rules.
    As specified in the October 2023 EPA Final Rule, and modified in 
the December 2023 EPA interim final rule, installation of central air 
conditioner and heat pump systems manufactured or imported on or after 
January 1, 2025, that use a refrigerant with a GWP higher than 700 
would be prohibited from being installed beginning on January 1, 2025. 
A system comprised of ``specified components'' manufactured or imported 
prior to January 1, 2025, can still be installed until January 1, 2026. 
The EPA's rule permits the continued manufacture, distribution, and 
installation of individual specified components that use higher GWP 
refrigerants on or after January 1, 2026, only as replacements for 
components in existing systems provided they are labeled for this use 
as specified in the EPA rule.
    The DOE definition of the term ``central air conditioner or central 
air conditioning heat pump'' in 10 CFR 430.2 specifies that 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. Further, the DOE 
definition specifies that 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). In 
addition, DOE's requirements in 10 CFR 429.16(a) specify required 
representations based on how the model is distributed in commerce 
(i.e., as part of a matched system, as an indoor unit only, or as an 
outdoor unit with no match).
    DOE's rules for testing and rating covered products to establish 
compliance with energy conservation standards apply to basic models as 
distributed in commerce by the manufacturer (or importer). Although the 
deadlines for installation of specified components under EPA's rule 
apply to certain products based on their date of manufacture or import 
(i.e., depending on whether they were manufactured prior to January 1, 
2025), DOE's rules for how the manufacturer must test, rate, and 
certify their products apply based on the date of manufacture (or 
importation) and on how each basic model is distributed in commerce 
(i.e., as part of a matched system or as an OUWNM), with the purpose 
being to ensure that each basic model complies with the energy 
conservation standard that applies to that basic model. A manufacturer 
or importer is not required to retest and/or recertify a basic model 
unless the manufacturer either makes a change to that basic model that 
would make it a new basic model under DOE's definition of that term in 
10 CFR 430.2 or makes a change to the configuration in which it is 
being distributed in commerce such that a different tested combination 
requirement applies to it under 10 CFR 429.16. Stated within the 
context of the EPA's rule, a basic model of condensing unit that 
previously had been rated and certified to DOE in one or more 
combinations would not have to be re-tested and rated under the OUWNM 
provisions until such a time as the manufacturer ceases distribution of 
that basic model as part of a matched pair and begins distributing it 
as an OUWNM. At that point, the manufacturer must test, rate, and 
certify that condensing unit under the OUWNM as a new basic model, as 
under the basic model definition in 10 CFR 430.2 the model as an OUWNM 
cannot be the same basic model as it would have been in a combination.
    For R-410A (or other refrigerant with GWP above 700) outdoor units 
manufactured (or imported) prior to January 1, 2025, which under the 
EPA's rule can still be installed as a system until January 1, 2026, 
the certifications of those models based on their tested combinations 
remain valid under DOE regulations as long as manufacturers continue to 
distribute them in commerce as a system. However, if at some point the 
manufacturer chooses to distribute in commerce the unit alone and not 
as a combination with any indoor units (either before January 1, 2026 
or after that date as a service-only replacement component to comply 
with EPA's rule), the outdoor unit would have to be tested, rated, and 
certified in accordance with the OUWNM provisions. This also applies 
for R-410A (or other refrigerant with GWP above 700) outdoor units 
manufactured or imported on or after January 1, 2025, as DOE expects 
that manufacturers would cease distribution of the outdoor units

[[Page 1238]]

as part of a combination, as these systems could no longer be installed 
anywhere in the U.S. This certification as a new basic model must be 
made prior to the date at which the manufacturer begins distributing 
those outdoor units as an OUWMN and would be indicated to DOE in its 
certification reports via a discontinued model filing for the model as 
distributed in a combination and certification as a new basic model of 
OUWNM.
    For an indoor unit intended only for replacement in an existing 
system and which is no longer distributed in commerce for installation 
as a combination, as would be the case for an existing system that uses 
a refrigerant banned by EPA, the requirement in 10 CFR 430.2 and table 
1 of 10 CFR 429.16(a) for the indoor unit to be rated as part of a 
system would still apply even though the indoor unit is no longer being 
distributed in commerce as part of a combination. This rating 
requirement would apply regardless of whether the manufacturer of the 
indoor unit is an ICM. If the indoor unit uses a refrigerant allowed by 
EPA only for component replacement (e.g., R-410A), the rating for such 
a unit would be based on a combination using that refrigerant, and per 
EPA regulations could not be distributed in commerce as a combination. 
However, this does not imply that the indoor unit cannot be rated, nor 
that the entire system would have to be replaced. DOE notes further 
that any such rating for the indoor unit must be compliant with current 
standards, and that any indoor units distributed in commerce for use in 
a system that uses a refrigerant subject to the EPA ban would need to 
have been certified to DOE as compliant with the applicable standards 
as part of a combination before January 1, 2025 and must have been 
tested and rated in every combination with an outdoor unit with which 
it has been previously distributed in commerce.
(d) Comments Received
    In their response to the NOPR, the Joint Advocates and Lennox fully 
supported the proposed provisions for OUWNMs. The Joint Advocates 
agreed that DOE's clarifying definition for OUWNM will help ensure 
representative ratings and that the proposed definition is consistent 
with DOE's intent in the June 2016 Final Rule. (Joint Advocates, No. 30 
at p. 3) Lennox strongly supported the DOE proposal that any outdoor 
unit designed for R-410A or any banned refrigerant as per EPA 
regulations, when distributed in commerce without an indoor unit on or 
after January 1, 2026, would be deemed an outdoor unit with no match. 
(Lennox, No. 24 at p. 2).
    Several commenters requested more clarity or expressed concerns on 
DOE's OUWNM provisions. These are discussed in the following 
subsections.
(1) OUWNM Definition
[GRAPHIC] [TIFF OMITTED] TR07JA25.000

    An Outdoor Unit that is not distributed in commerce by the 
manufacturer with any indoor units, and that meets any of the following 
criteria:
    (a) is designed for use with a refrigerant that makes the unit 
banned for installation when paired with a new Indoor Unit as a system, 
according to EPA regulations in 40 CFR chapter I, subchapter C,
    [provisions (b) and (c) unchanged]
    Rheem requested that DOE consider simplifying the proposed 
definition for OUWNMs because some of the bullet points may overlap or 
conflict with each other. (Rheem, No. 34 at p. 3) Rheem noted that in 
SNAP Final Rule 237, EPA has approved R-32, R-452B, R-454A, R-454B, R-
454C, and R-457A for use in residential and light commercial air-
conditioning and heat pump end use, which also includes CAC/HPs. (Id.) 
Rheem commented that among these substitutes, R-454C and R-457A have a 
95 [deg]F midpoint saturation absolute pressure within 18 percent of 
the 95 [deg]F saturation absolute pressure for R-22, thus meeting the 
provisions in 4.1(b) and 3.1(b) of the proposed OUWNM definition at 
appendix M1 and appendix M2, respectively. (Id.) Rheem suggested that 
DOE simplify the definition of OUWNM to avoid confusion. (Id.)
    DOE appreciates that AHRI is taking steps to update AHRI 210/240-
2024 and AHRI 1600-2024 standards to broaden the OUWNM provisions 
beyond R-22 outdoor units and make them applicable to any outdoor units 
that are distributed in commerce without an indoor matching pair, 
regardless of the refrigerant the outdoor unit employs. Such an 
implementation would be consistent with DOE's proposed definition of 
OUWNMs in the April

[[Page 1239]]

2024 NOPR. DOE disagrees with the addition of ``by the manufacturer'' 
in the OUWNM definition to qualify distribution in commerce, since 
under EPCA the term ``distribution in commerce'' also applies to 
subsequent distribution after the initial offering by the manufacturer. 
The proposed addition would undercut the general applicability of that 
term across the distribution chain as established in EPCA. As explained 
in DOE's March 7, 2011, final rule that established the certification 
provisions in Part 429, application of the term ``distribution in 
commerce'' would depend on a particular manufacturer's production 
practices, business decisions, and the facts and circumstances of a 
particular case. 76 FR 12422, 12426. . However, DOE agrees with the 
inclusion of the term ``new'' to clarify that the EPA ban specifically 
pertains to new system installations, and for further clarification is 
including the term ``new'' to describe both the indoor unit with which 
the outdoor unit is paired and the newly created system. In addition, 
notwithstanding the broad applicability of the term ``distribute in 
commerce,'' DOE notes that under 10 CFR 429.102(a)(6) it is a 
prohibited act for a manufacturer or private labeler to distribute in 
commerce any new covered product or covered equipment that is not in 
compliance with an applicable energy conservation standard prescribed 
under the Act, and therefore the obligation to certify that basic 
models are in compliance with the standards lies with the manufacturer 
and importer. This is also the basis for the requirement in 10 CFR 
429.12(a) that each manufacturer, before distributing in commerce any 
basic model of a covered product or covered equipment subject to an 
applicable energy conservation standard, certify that the model meets 
the applicable energy conservation standard.
    DOE agrees with Rheem that certain SNAP-approved refrigerants, for 
example R-454C and R-457A, have pressure-temperature relationship 
characteristics similar to R-22 and would meet provision (b) of the 
proposed OUWNM definition. DOE notes that both these refrigerants have 
GWPs equal to or less than 150, and thus could potentially be under 
consideration for future reductions in GWP as compared with 
refrigerants R-454B and R-32, the primary near-term candidates for 
transition from R-410A. To ensure that these SNAP-approved refrigerants 
would not be subject to provision (b) of the proposed OUWNM definition, 
DOE is qualifying provision (b) with a GWP limit--specifically, only 
refrigerants with GWP greater than 150 (per EPA's measure) would be 
subject to provision (b).
    In summary, DOE is making minor modifications to the OUWNM 
definition as follows:
    An Outdoor Unit that is not distributed in commerce with any indoor 
units, and that meets any of the following criteria:
    (a) Is designed for use with a refrigerant that makes the unit 
banned for installation when paired with a new Indoor Unit as a system, 
according to EPA regulations in 40 CFR chapter I, subchapter C;
    (b) Is designed for use with a refrigerant that has a 95 [deg]F 
midpoint saturation absolute pressure that is 18 percent of 
the 95 [deg]F saturation absolute pressure for R-22 and a global 
warming potential greater than 150 per EPA regulations in 40 CFR 84.64; 
or
    (c) Is shipped without a specified refrigerant from the point of 
manufacture or is shipped such that more than 2 pounds of refrigerant 
are required to meet the charge per section 5.1.8 of AHRI 210/240-
2024.\36\ This shall not apply if either (a) the factory charge is 
equal to or greater than 70 percent of the outdoor unit internal volume 
times the liquid density of refrigerant at 95 [deg]F, or (b) an A2L 
refrigerant is approved for use and listed in the certification report.
---------------------------------------------------------------------------

    \36\ For Appendix M2, the definition references section 5.1.8 of 
AHRI 1600-2024.
---------------------------------------------------------------------------

(2) Clarity on Interaction With EPA Rule
    AHRI and Carrier requested further clarity on how DOE's OUWNM 
provisions will interface with the October 2023 EPA final rule, 
particularly in terms of timing and scope. (AHRI, No. 25 at pp. 2-4; 
Carrier, No. 29 at p. 3)
    AHRI appreciated DOE's proposal to expand the OUWNM definition to 
include HFC refrigerants having a GWP greater than 700, in line with 
EPA's ban, but noted that the interaction between the EPA and DOE 
regulations are complex and implementation questions remain. (AHRI, No. 
25 at p. 2) AHRI cautioned that care must be taken to ensure industry 
and downstream distribution partners understand and can remain 
compliant with applicable regulations and that consumers who recently 
installed products with R-410A refrigerant have meaningful access to 
service parts for the useful life of their equipment. (Id.) AHRI noted 
that while no date has been included with the DOE-proposed OUWNM 
definition, the NOPR preamble presents the proposed date of 2026. 
(AHRI, No. 25 at p. 3) AHRI sought clarification that OUWNM ratings 
would only be required for split-system outdoor units using HFC 
refrigerants having a GWP greater than 700 manufactured after January 
1, 2025. (Id.) AHRI attached a spreadsheet (Exhibit 1) that contained 
requests for clarification from DOE on questions regarding the 
prohibitions for manufacture, distribution, and installation of various 
product types. (AHRI, No. 25 at pp. 5-6). Specifically, AHRI requested 
clarification on whether DOE's proposal applies to split-system CAC/HP 
products imported into the United States, but which are not for sale in 
the United States. (Id.)
    Carrier appreciated DOE's intent to further clarify the OUWNM 
requirements and noted that it is clear that the OUWNM category is the 
equivalent of EPA's service-only condenser allowance in the market. 
(Carrier, No. 29 at p. 3) Carrier commented that it supports DOE 
stating the application of OUWNM requirements to a service-only R-410A 
condensing unit, but requested that DOE provide additional clarity in 
the final rule on certain aspects, including effective date, which unit 
types OUWNM applies to, and the indoor airflow requirements. (Id.) In 
particular, Carrier requested that DOE make the following 
clarifications to better help the regulated community in complying with 
applicable efficiency and refrigerant regulations: (1) R-410A 
condensing units manufactured or imported on or after January 1, 2025 
would need to be tested and rated as an OUWNM because EPA prohibits the 
installation of those outdoor units with a new indoor unit; (2) any R-
410A outdoor and indoor units manufactured before January 1, 2025 could 
be sold and installed utilizing the existing DOE-certified system 
rating, because EPA is allowing installation; (3) since EPA prohibits 
the sale and installation of any R-410A outdoor and indoor units in 
2026 regardless of production date, any remaining pre-2025 inventory 
held by a manufacturer would be required to be recertified using the 
OUWNM procedure when distributed in commerce on or after January 1, 
2026; and (4) any pre-2025 R-410A air conditioners in the Southeast or 
Southwest regions could not be installed without being recertified as 
an OUWNM. (Carrier, No. 29 at p. 3)
    In response to AHRI, DOE clarifies that OUWNM ratings for split-
system outdoor units employing refrigerants with GWP greater than 700 
would be required for units distributed in commerce as service-only 
placement

[[Page 1240]]

components (i.e., not as a combination) from the point of manufacture 
and thus subject to DOE's testing and rating requirements for outdoor 
units with no match in Appendix M1 and 10 CFR 429.16. As discussed in 
the previous section of this notice, DOE expects that manufacturers 
would need to make this transition for units manufactured after January 
1, 2025, which it intends to make available as service-only replacement 
components for existing systems. Regarding units that are imported into 
the United States but not distributed and sold for installation within 
the United States, DOE notes that its requirements specified in 10 CFR 
parts 429, 430, and 431 shall not apply to any covered product or 
covered equipment if: (a) such covered product or covered equipment is 
manufactured, sold, or held for sale for export from the United States 
or is imported for export; (b) such covered product or covered 
equipment or any container in which it is enclosed, when distributed in 
commerce, bears a stamp or label stating ``NOT FOR SALE FOR USE IN THE 
UNITED STATES''; and (c) such product is, in fact, not distributed in 
commerce for use in the United States. 10 CFR 429.6.
    DOE notes that the additional detail provided in the preceding 
section of this notice, and in the preceding paragraphs, is largely 
consistent with Carrier's suggestions. However, DOE wishes to correct 
two of Carrier's clarifications: (1) the recertification of remaining 
pre-2025 inventory would not be required provided those basic models 
were correctly certified based on how they were distributed at the time 
of their manufacture; and (2) the applicability of these provisions for 
units to be installed in the Southeast or Southwest do not differ from 
products subject to nationwide standards. The only difference for 
installation in the Southeast or Southwest is that the regional energy 
conservation standards would apply for such installations, as would 
otherwise be the case per 10 CFR 430.32(c)(6), and the efficiency 
rating as certified by the manufacturer must indicate those basic 
models comply with the applicable regional standards and may be 
installed in the Southeast and/or Southwest regions.
(3) Recertification of Units Already Distributed in Commerce
    Several commenters expressed concern with the recertification as 
OUWNMs of units already distributed in commerce, when installed after 
January 1, 2026.
    AHRI sought clarification on the intended meaning of the phrase 
``distributed in commerce.'' (AHRI, No. 25 at p. 3) AHRI noted that the 
current DOE regulation places no restrictions on distribution of 
products if the product was initially certified and regional standards 
are not an issue for the product and location. (AHRI, No. 25 at p. 6) 
AHRI noted that DOE's NOPR proposal requires existing outdoor models 
currently distributed in commerce as part of a split-system basic model 
that transition to a replacement outdoor unit only to be tested, rated, 
and recertified under the provisions in 10 CFR 429.16 for an outdoor 
unit with no match. (Id.) AHRI noted that per EPCA, ``distribution in 
commerce'' means ``to sell in commerce, to import, to introduce or 
deliver for introduction into commerce, or to hold for sale or 
distribution after introduction into commerce,'' and that 
``distribution in commerce'' applies to both the initial offering for 
sale by the manufacturer and the subsequent distribution by downstream 
partners (i.e., sale by the distributor to the contractor, or the 
contractor to the homeowner). (Id.) AHRI cautioned that without linking 
the requirements to a manufacture/import date, DOE's proposal 
complicates the distribution of outdoor units manufactured pre-2025 
that are no longer in possession of the manufacturer or private 
labeler. (Id.) AHRI questioned how DOE will enforce the proposal on 
products subject to national energy efficiency standards. (Id.)
    AHRI contended that for products subject to national standards, DOE 
is constrained by the application of the base national standard, which 
``applies to all products manufactured or imported into the United 
States on and after the effective date of the standard.'' \37\ (AHRI, 
No. 25 at p. 6) Therefore, AHRI asserted that space-constrained 
products; small-duct high-velocity, air conditioners in the North; and 
heat pumps manufactured or imported prior to January 1, 2025 that were 
certified as compliant with the base national standard can still be 
installed in the United States until the inventory is depleted. (Id.) 
AHRI questioned how DOE could require manufacturers, distributors, or 
contractors to retroactively apply testing, rating, or certification 
requirements on outdoor units subject to national standards that were 
distributed in commerce and are no longer in the manufacturer's 
possession. (AHRI, No. 25 at pp. 6-7) AHRI requested for DOE to link 
the OUWNM definition to a manufacture/import date, as DOE's proposal 
complicates the distribution of outdoor units manufactured prior to 
January 1, 2025 that are no longer in possession of the manufacturer 
(or private labeler). (AHRI, No. 25 at p. 7) Similarly, for products 
subject to regional standards, AHRI questioned how DOE could require 
manufacturers, distributors, or contractors to retroactively apply 
testing, rating, or certification for outdoor units manufactured/
imported in 2024 and no longer in possession of the manufacturer. (Id.) 
AHRI requested clarification on whether DOE intended that air 
conditioners slated for the Southeast and Southwest regions, 
manufactured/imported in 2024, and still in possession of the 
manufacturer be recertified as OUWNMs on January 1, 2025. (Id.)
---------------------------------------------------------------------------

    \37\ 42 U.S.C. 6295(o)(6)(E).
---------------------------------------------------------------------------

    AHRI noted that while the NOPR preamble states that ``the basic 
model number would need to change to reflect that the outdoor unit is 
no longer part of a combination as previously certified, but rather as 
an outdoor unit with no match, but the outdoor unit model could still 
be assigned the same individual model number,'' DOE has not described 
in the proposed regulatory text how the testing, rating, and 
recertification for outdoor units distributed in commerce by outdoor 
unit manufacturers (``OUMs'') for a former certified combination that 
transitions to OUWNMs for replacement will be completed. (AHRI, No. 25 
at p. 6) AHRI expressed concern that this may create logistical 
complications, given that ``distributed in commerce'' applies to both 
the initial sale and the subsequent sale of products that have already 
entered commerce and are no longer in the possession of the 
manufacturer to be recertified. (Id.) AHRI contended that certification 
of a condensing unit as an OUWNM should apply to products manufactured 
after January 1, 2025. (Id.)
    HARDI strongly opposed any restriction on the ability of its 
members to sell products already in inventory, including install date 
regulations, such as EPA's transitions program and the statutorily 
required install date in DOE's regional standards for split-system 
central air conditioners. (HARDI, No. 26 at pp. 1-2) HARDI commented 
that it believed install date requirements hinder the ability of the 
heating, ventilation, air-conditioning, and refrigeration industry to 
move to more energy-efficient or environmentally friendly products and 
that install date regulations that cause dead inventory are ineffective 
because they create waste, increase costs, and constitute a

[[Page 1241]]

regulatory taking.\38\ (Id.) HARDI commented that it was its 
understanding that the phrase ``currently distributed in commerce'' 
does not intend to include CAC/HP equipment already in distributors' 
warehouses, but it asserted that, just like with the confusing 
compliance regime caused by the install date associated with regional 
standards for split-system central air conditioners, if this phrase is 
used in the final regulation, local compliance officials will prevent 
repairs to existing systems if the outdoor unit does not have proof of 
meeting the minimum efficiency standard. (HARDI, No. 26 at p. 2) HARDI 
suggested that the best course of action is to apply the OUWNM testing 
and certification requirements at the same date of manufacture timeline 
as the EPA requirement for outdoor condensing units to be marked ``For 
servicing existing equipment only.'' (Id.) HARDI noted that for split-
system CAC/HPs, EPA requires anything manufactured after January 1, 
2025 to be marked ``For servicing existing equipment only.'' (Id.) 
HARDI further noted that while new split-system CAC/HPs can be 
installed until January 1, 2026 using R-410A or other high-GWP 
refrigerants, EPA requires those systems to be manufactured before 
January 1, 2025, and outdoor units manufactured after January 1, 2025 
can only be used as components, thereby meeting the proposed definition 
of OUWNMs. (Id.) HARDI recommended that DOE limit the need to test, 
rate, and recertify equipment to only outdoor units manufactured after 
January 1, 2025, as this will ensure that equipment intended to be 
installed as an OUWNM does meet the minimum efficiency requirements 
while not affecting equipment originally sold for installation as a 
matched system. (Id.)
---------------------------------------------------------------------------

    \38\ HARDI notes that a regulatory taking is a ``taking of 
property under the Fifth Amendment by way of regulation that 
seriously restricts a property owner's rights,'' Blacks Law 
Dictionary, 11th Edition. (HARDI, No. 26 at p. 1).
---------------------------------------------------------------------------

    JCI expressed concerns with DOE's proposal to require 
recertification of units ``currently distributed in commerce'' to meet 
the OUWNM requirements, contending that requiring recertification of a 
component as part of a system that was previously certified as 
compliant and has already entered commerce, i.e., is no longer in the 
possession of the original manufacturer, is overly burdensome for 
manufacturers, distributors, and contractors, and will be problematic 
for DOE to enforce without tying enforcement to the manufacture/import 
date. (JCI, No. 35 at p. 2) JCI recommended that for outdoor units that 
have entered commerce, the ``date of manufacture'' be used as the 
enforcement mechanism. (Id.) JCI commented that it was its 
understanding that outdoor units manufactured on or after January 1, 
2025 would be required to meet DOE's OUWNM criteria if they were still 
in the possession of the original manufacturer. (Id.) JCI stated that 
clarifying that the OUWNM requirements would take effect on January 1, 
2025, versus the NOPR date of January 1, 2026, reduces the amount of 
inventory in the channel that would require recertification. (Id.)
    Rheem also expressed concern about language for OUWNMs applicable 
to ``existing outdoor models currently distributed in commerce,'' where 
these products would need to be recertified and given a new basic model 
number in the event that they are only eligible for component 
replacement per EPA's Technology Transitions rule. (Rheem, No. 34 at p. 
3) Rheem asserted that the notion of obtaining proof of new rating and 
a different model number is unreasonable to require once the equipment 
has left manufacturer warehouses, as the application of new labels and 
rating certifications is impractical to carry out at the distributor 
and installer levels. (Id.) Rheem commented that EPA appears to 
recognize this impracticality and does not require relabeling of 
equipment made prior to January 1, 2025 to indicate ``for service 
only.'' (Id.) Rheem contended that a change in the test procedure 
should not render obsolete a product currently in commerce that was 
compliant at the time of manufacture. (Id.)
    As indicated by AHRI, DOE notes that per EPCA, the terms ``to 
distribute in commerce'' and ``distribution in commerce'' mean to 
``sell in commerce, to import, to introduce or deliver for introduction 
into commerce, or to hold for sale or distribution after introduction 
into commerce.'' (42 U.S.C. 6291(16)) Under the statutory definition, 
this term can apply to the initial offering of sale by a manufacturer 
or by subsequent distribution by downstream partners. As was discussed 
in the previous section, the December 2023 EPA Interim Final Rule 
allows for a 1-year sell-through period (until January 1, 2026) for any 
CAC/HP system employing a refrigerant with a GWP of 700 or greater, 
provided the specified component is manufactured or imported prior to 
January 1, 2025 (see 40 CFR 84.54(c)(1)). Since EPA prohibits the 
installation of any specified CAC/HP components to create a new system 
employing a refrigerant with a GWP of 700 or greater on or after 
January 1, 2026, irrespective of the manufacturing date, any remaining 
pre-2025 inventory (i.e., imported or manufactured before January 1, 
2025) held by any channel of distribution (manufacturer or distributor) 
could not be installed as a system after January 1, 2026.
    DOE's rating and certification requirements in 10 CFR 429.16 for 
central air conditioners and heat pumps apply based on how a 
manufacturer distributes the models in commerce. If the manufacturer 
ceases distribution in commerce of a model of outdoor unit that was 
previously part of a combination and begins distributing it only as an 
OUWNM to allow for use as a service-only replacement under the EPA's 
rules for components of an R-410A system, that model of outdoor unit 
would need to be recertified under the OUWNM requirements regardless of 
when that transition occurs, since the manufacturer (or private 
labeler) has an obligation to ensure that any basic model it 
distributes is compliant with the applicable energy conservation 
standard for the configuration (or configurations) in which the 
manufacturer distributes it. However, the requirement to recertify 
those basic models does not apply retroactively to units of a basic 
model that were already distributed in commerce as part of a 
combination and had been correctly certified according to DOE's 
regulations.
    Regarding AHRI's concern about enforcement of national standards, 
DOE notes that no changes were proposed to national standards in the 
April 2024 NOPR, and none are being finalized in this rulemaking. The 
purpose of the clarification provided in this rulemaking is to ensure 
that manufacturers have a clear understanding of how to comply with 
DOE's certification requirements for products that will be subject to 
EPA regulations. DOE's certification provisions in 10 CFR 429.12(a) 
specify that each manufacturer, before distributing in commerce any 
basic model of a covered product or covered equipment subject to an 
applicable energy conservation standard set forth in parts 430 or 431, 
and annually thereafter . . . shall submit a certification report to 
DOE certifying that each basic model meets the applicable energy 
conservation standard(s). To the extent that outdoor units that were 
previously certified as compliant as part of a matched system begin 
being distributed in commerce as outdoor units with no match, they are 
being distributed as a new basic model, and therefore, must certify 
compliance with the applicable energy conservation

[[Page 1242]]

standards. The application of the base national standard, as referenced 
by AHRI, still applies to the outdoor unit based on its manufacture 
date, but compliance with that standard must be determined for the 
basic model distributed in commerce (i.e., the OUWNM).
    DOE notes that the EPA regulations include a 1-year sell-through 
period to reduce inventory of units that may be in danger of not 
complying with the EPA rule. DOE's rationale also applies to AHRI's 
concern on regional standards. However, DOE notes that there is 
confusion on the applicability of the EPA dates on the regional level. 
DOE clarifies, consistent with the national application, that air 
conditioners certified as able to be installed in the Southeast and 
Southwest regions manufactured or imported before January 1, 2025, and 
that have already been distributed in commerce, would not need to be 
certified as OUWNMs on January 1, 2025, provided the manufacturer had 
already certified compliance with the applicable energy conservation 
standards. For units intended for installation in the Southeast or 
Southwest regions, this would include a certification that they comply 
with those applicable standards. As previously explained in this 
notice, the only distinction from CAC/HP products that are not subject 
to regional efficiency standards is that split-system AC outdoor units 
certified as OUWNM would have to meet the applicable standards for the 
Southeast or Southwest regions to be installed in those regions.
    DOE notes there may be confusion regarding the applicability of the 
compliance dates in the EPA rule and how these dates affect DOE 
regional standards requirements. To be clear, the EPA rule has no 
effect on DOE requirements. For certain split-system central air 
conditioning systems or certain OUWNMs to be installed in the Southeast 
or Southwest region consistent with DOE regional standards 
requirements, the system/OUWNM must be certified to DOE as compliant 
with the applicable regional standard(s), and the certification must 
indicate that the model/combination can be installed in the Southeast 
and/or Southwest region. While the EPA rule may change the approach a 
manufacture may take with respect to testing and certifying a 
particular model, it does not change DOE requirements.
    In response to AHRI's concern that DOE has not described in the 
proposed regulatory text how the testing, rating, and recertification 
for OUWNMs will be completed, DOE notes that the testing requirements 
are laid out in section 4.2 of revised appendix M1 and section 3.2 of 
new appendix M2. Additionally, as noted in the April 2024 NOPR, and 
explained in the preceding section of this notice, existing outdoor 
models currently distributed in commerce as part of a split-system 
basic model that the manufacturer transitions to a replacement outdoor 
unit only would need to be tested, rated, and certified under the 
provisions in 10 CFR 429.16 for an outdoor unit with no match. 89 FR 
24206, 24231. As described previously in this section, distribution of 
such a model as an OUWNM represents distribution in commerce of a new 
basic model, and accordingly, the basic model must be certified as 
compliant with the applicable energy conservation standards. DOE may 
consider additional certification requirements under a separate 
rulemaking regarding appliance and equipment certification.
    In response to HARDI, DOE clarifies that the reporting obligations 
apply to manufacturers, and importers, and thus basic models previously 
distributed in commerce by the manufacturer that were certified by the 
manufacturer in accordance with 10 CFR 429.12 do not need to be 
recertified. Regarding HARDI's criticism of regulation based on install 
date requirements, DOE clarifies that, whereas the EPA rule is based on 
the date of installation, the application of the OUWNM provisions are 
based on the configuration in which the manufacturer (or importer) 
distributed the basic model from the point of manufacture (or import). 
It does not depend upon distributor or retail sales and offerings. DOE 
notes that the EPA regulations include a 1-year sell-through period for 
pre-2025 inventory to provide time to reduce inventory. The OUWNM 
provisions in this rulemaking simply align with the EPA action 
undertaken in the October 2023 EPA rule. In response to HARDI's 
recommendation to limit the need to test, rate, and recertify equipment 
to only outdoor units manufactured after January 1, 2025, DOE agrees 
that most inventory manufactured prior to January 1, 2025, will likely 
be distributed in commerce with indoor units and be installed prior to 
January 1, 2026; however, to the extent that any outdoor units 
manufactured prior to January 1, 2025, continue to be distributed in 
commerce by the manufacturer after January 1, 2026, as OUWNM, the 
manufacturer must test consistent with the requirements applicable to 
OUWNMs and certify the compliance of such models with the applicable 
energy conservation standard.
    In response to JCI, DOE again stresses that the timing for 
implementation of the OUWNM provisions is tied to the EPA rule. 
Specifically, an outdoor unit no longer has a match when EPA 
requirements no longer allow installation with an indoor unit to create 
a new system, and thus must be certified to DOE as an OUWNM as it 
continues to be distributed in commerce. As discussed in III.E.7.c(2), 
DOE clarifies that any outdoor CAC/HP units manufactured or imported on 
or after January 1, 2025 and employing refrigerants with GWP greater 
than 700 (for example, R-410A), would need to be tested and rated as an 
OUWNM, consistent with the EPA requirement that such models be used 
``for servicing existing equipment only.'' For units manufactured or 
imported before January 1, 2025 the existing DOE-certified system 
rating can be used, provided the manufacturer does not continue 
distribution of the outdoor units alone, because the EPA regulations 
permit installations of such systems until January 1, 2026. However, if 
the unit is distributed in commerce alone and not as a combination with 
any indoor units, as likely would be the case for products intended for 
installation as an individual replacement component of an existing 
system, the outdoor unit would have to be certified in accordance with 
the OUWNM provisions prior to the date at which the manufacturer begins 
distributing those outdoor units as an OUWMN, as indicated to DOE in 
its certification reports via a discontinued model filing for the model 
as distributed in a combination and certification as an OUWNM.
    In response to Rheem's claim that EPA does not require relabeling 
of equipment made prior to January 1, 2025 to indicate ``for service 
only,'' DOE notes that the EPA labeling requirement at 40 CFR 84.58(b) 
states, ``Effective upon the date listed for each subsector in Sec.  
84.54(c) . . . any specified component . . . that uses or is intended 
to use any regulated substance, or blend containing any regulated 
substance . . . must have a permanent label compliant with paragraph 
(c) \39\ of this section containing the information in paragraph (a)(1) 
of this section. For specified components that are intended for use

[[Page 1243]]

with a regulated substance or blends containing a regulated substance 
that exceed the applicable GWP limit or HFC restriction, the label must 
state ``For servicing existing equipment only'' in addition to the 
other required labeling elements.'' (See 40 CFR 84.58(b)) 40 CFR 
84.58(c) requires the label to list, at a minimum, the refrigerant and 
the date of manufacture. DOE is aware that there are two dates listed 
in the relevant paragraph for split-system CAC/HPs under section Sec.  
84.54(c)--January 1, 2025 and January 1, 2026. As discussed above and 
in the preceding section of this notice the December 2023 EPA Interim 
Final Rule pushed back the restriction on R-410A and similar 
refrigerants such that components manufactured prior to January 1, 2025 
could be installed as part of systems prior to January 1, 2026, and 
thereafter would be installable only for servicing existing equipment. 
Thus, unless EPA intended for the ``for servicing existing equipment 
only'' words to be on specified components starting January 1, 2025, 
when they would still be allowed to be used for system installations, 
EPA regulations effectively state that the required label would have to 
be applied or changed while the component is in distribution, i.e., 
after leaving the manufacturer but before installation. However, DOE 
notes that these labeling provisions are separate from its own 
regulatory requirements and that manufacturers seeking more specific 
guidance on the implementation of these provisions should consult EPA.
---------------------------------------------------------------------------

    \39\ The reference is to paragraph (c) but should be to 
paragraph (d), which specifies label design (e.g., English language, 
durable and printed/affixed to the product exterior surface, readily 
visible and legible, etc.). Paragraph (c) addresses products in the 
foam or aerosol sector and is not relevant for the refrigeration, 
air-conditioning, and heat pump sector addressed in paragraph (b).
---------------------------------------------------------------------------

    Regarding Rheem's contention that a change in the test procedure 
should not render a currently compliant product obsolete, DOE notes 
that it is the EPA action, and not a change to the DOE test procedure, 
that would prevent the installation of a previously certified CAC/HP 
system. In accordance with this EPA action, DOE's OUWNM provisions in 
the test procedure provide a means for manufacturers to assign an 
energy efficiency rating to split-system outdoor units after the EPA 
has banned them for full-system installations. As discussed earlier in 
this section and in the preceding section, to the extent that the 
manufacturer of the outdoor unit of a previously certified CAC/HP 
system begins distributing it in commerce as an OUWNM, it would become 
a new basic model and the manufacturer would need to certify that it 
complies with the applicable energy conservation standard.
    In a comment related to concerns regarding recertification as OUWNM 
of outdoor units already distributed in commerce, GE Appliances 
indicated that products currently in production would need redesign to 
comply with cut-out/cut-in temperature and CVP enforcement testing. (GE 
Appliances, No. 37 at p. 6) They commented that since import and 
production of legacy R-410A equipment will cease after January 1, 2025, 
there will be no need to redesign existing inventory, in order to 
comply with the cut-out/cut-in temperature and CVP enforcement test. 
Id. They pointed out that most of DOE`s energy efficiency enforcements 
are based on date of import or manufacture, so exclusion of R-410A 
legacy equipment from CVP and cut-out/cut-in enforcement testing would 
be consistent with this practice, and that failing to exclude these 
products from such enforcement would lead to stranded inventory, 
resulting in the loss of embodied carbon in the inventory, with little/
no energy efficiency saving. Id.
    In response to the comment by GE Appliances, certifications 
required to be made by a manufacturer for the compressor and indoor 
blower speed of any variable capacity system at specific test 
conditions must represent normal operation. The CVP provisions 
established in this final rule describe how DOE would verify that 
certified values are appropriate for the purposes of DOE enforcement 
testing. Hence, DOE would expect existing properly-certified variable 
speed CAC/HPs and CHPs to pass the CVP enforcement with minimal or no 
adjustment to existing performance representations. Further, DOE 
certainly would not expect changes sufficient to call into question the 
compliance of such models with DOE efficiency standards. Similarly, 
although cut-out and cut-in temperatures are not currently required to 
be certified, DOE would expect manufacturers to have certified HSPF2 
values that are consistent with the actual cut-out/cut-in 
characteristics of certified models. Manufacturers are not required 
themselves to conduct CVP testing. To the extent that manufacturers are 
correctly certifying performance of existing models, there would be no 
need to recertify or redesign such models in response to DOE 
implementing CVP testing for enforcement purposes. Therefore, DOE 
disagrees with the suggestion of GE Appliances, that there should be 
specific exclusions for legacy R-410A CAC/HPs from the CVP and cut-out/
cut-in temperature enforcement provisions.
(4) Applicability to Multi-Head Mini-Splits, Multi-Splits, and Multi-
Circuit Systems
    AHRI and Carrier requested clarity on whether the OUWNM provisions 
are applicable to multi-head mini-split, multi-split, or multi-circuit 
systems. (AHRI, No. 25 at pp. 4-5; Carrier, No. 29 at pp. 3-4).
    Carrier requested that DOE confirm that the OUWNM certification 
requirement is applicable to all split-system condensing units within 
the scope of appendix M1, which includes single-split, multi-head mini-
split, multi-split (including VRF), and multi-circuit air conditioner 
and heat pump systems. (Carrier, No. 29 at pp. 3-4) Specifically, 
Carrier commented that it believes multi-head mini-split and multi-
split systems should also require the OUWNM certification. (Id.) 
Carrier noted that while these systems are generally intended to be 
installed with multiple indoor units, they can be installed with a 
single indoor unit, which could be ducted or ductless, and that 
multiple manufacturers have combinations that utilize a mini-split 
(traditionally known as a ``ductless outdoor unit'') with a 
conventional ``ducted'' indoor unit and coil combination. (Id.) Carrier 
further noted that multi-split and mini-VRF outdoor units are able to 
be rated, certified, and used in combination with a single indoor unit 
as well as the typical multiple indoor units. (Id.) Carrier expressed 
concern that if OUWNM provisions are not required for these systems 
that can be installed with a single indoor unit, they could be used to 
replace the condenser on a system with an indoor unit that was never a 
certified combination, yielding poor system efficiencies. (Id.) Carrier 
commented that it was its understanding that EPA's reasoning to allow a 
service-only condenser was to address the customer concern of replacing 
their entire system upon a part failure in the condenser. (Id.) Carrier 
stated that in its experience, this does not happen regularly in the 
market, and if there is a premature part failure in the condenser, the 
part (i.e., compressor, expansion valve, motor, control board, or coil) 
is replaced or repaired, especially in the case of complex outdoor 
units such as multi-split condensers. (Id.) Carrier noted that in the 
situation the condenser fails at end of life, it is common practice to 
replace the entire system. (Id.) For these reasons, Carrier requested 
that DOE clarify that all split-system condensing units within the 
scope of appendix M1 that are manufactured beginning January 1, 2025 
with R-410A or any banned refrigerant must be certified as an OUWNM. 
(Id.).
    AHRI noted that appendix M1 defines the tested combination of a 
multi-head mini-split, multi-split, or multi-circuit system to consist 
of one outdoor unit

[[Page 1244]]

with one or more compressors matched with between two and five indoor 
units. (AHRI, No. 25 at p. 4) AHRI further noted that appendix M1 
requires that these indoor units must collectively have a nominal 
cooling capacity greater than or equal to 95 percent and less than or 
equal to 105 percent of the nominal cooling capacity of the outdoor 
unit. (Id.) AHRI requested that DOE confirm (1) if multi-head systems 
would test as OUWNM with one or two indoor units per appendix M1, 
section 2.2(e); and (2) if the preference is for testing multi-head 
systems with two (or more) indoor units, whether the coil-only indoor 
unit coil shall be split evenly between the two, or in another 
configuration. (AHRI, No. 25 at pp. 4-5).
    DOE agrees with the reasons presented by Carrier and clarifies that 
the OUWNM provisions are applicable to all split-system CAC/HPs within 
the scope of appendix M1--including single-split, multi-head mini-
split, multi-split (including VRF), and multi-circuit air conditioner 
and heat pump systems. As noted by AHRI, per appendix M1, the tested 
combination of a multi-head mini-split, multi-split, or multi-circuit 
system requires between two and five indoor units. However, the indoor 
unit requirements (which are based on the highest sales volume family) 
are not explicitly applicable for OUWNM testing. As indicated by 
Carrier, multi-head systems can be installed and are able to be rated 
with either a single indoor unit or multiple indoor units. To provide 
maximum flexibility to manufacturers and to limit test burden, DOE 
clarifies that, for multi-head systems being certified under the 
outdoor unit with no match provisions, (1) multi-head systems capable 
of being paired with a single indoor coil shall be tested with a single 
indoor coil; and (2) multi-head systems incapable of being paired with 
a single indoor coil shall be tested with the least amount (between two 
to five) of identical indoor coils. If testing with two or more indoor 
coils, all coils shall have the same dimensions. The current testing 
instructions in section 2.2(e) of appendix M1 \40\ are written for a 
single indoor coil, but the same concept of the NGIFS can be extended 
to two or more identical indoor coils. Specifically, when evaluating 
NGIFS with two or more indoor coils, the total summation of the fin 
surface area would include all coils. DOE may consider certification 
requirements to include whether one or more indoor coils were used to 
evaluate an OUWNM rating in a separate rulemaking.
---------------------------------------------------------------------------

    \40\ These instructions are also included in sections 5.1.6.2 
and 5.1.6.3 of AHRI 210/240-2024 and AHRI 1600-2024.
---------------------------------------------------------------------------

(5) Control Type and Communicating System
    Carrier also requested that DOE clarify that OUWNM certification is 
required for all condensing units, regardless of the control type being 
used to generate the system rating. (Carrier, No. 29 at p. 4) Carrier 
noted that many of the communicating variable-speed condensers on the 
market today also have the capability to operate with a conventional 
24-V non-communicating thermostat and that it would be extremely 
difficult to exclude these units from the OUWNM certification and 
ensure they were actually being matched with a certified communicating 
indoor unit that was previously installed. (Id.)
    Conversely, GE Appliances commented that multi-head ductless split 
systems and VRF systems under 65k BTU, which are almost always 
variable-speed communicating systems, are unable to complete the 
existing test procedure for an OUWNM listing, as existing software does 
not support or allow a coil-only match without connection to a matched 
indoor unit. (GE Appliances, No. 37 at p. 4) GE asserted that the 
inability to provide replacement outdoor units to service existing 
communicating systems will lead to significant harm for consumers, the 
environment, and DOE's goals for heat pumps and variable-speed systems. 
(Id.) GE Appliances requested that DOE allow outdoor-unit-only listings 
for variable-speed communicating systems capable of supporting multiple 
indoor coils based on the lowest-performing system performance for the 
outdoor coil for any previously listed system or currently produced, 
compatible communicating coil. (Id.) GE Appliances asserted that 
because outdoor units for communicating systems can generally only work 
with matched indoor units using the same communications protocol, there 
is little risk of improper combinations to create systems that perform 
worse than efficiency levels required by DOE. (Id.) GE Appliances 
further commented that listing OUWNM units for these systems in this 
manner ensures accurate consumer information about expected product 
performance and also ensures service components' availability where 
they would otherwise be restricted. (Id.)
    Mitsubishi also asserted that while it understands the broad 
industry support for DOE to extend the definition of OUWNM to R-410A 
outdoor units, the proposed language does not take into account the 
emergence and expansion of communicating variable-speed equipment. 
(Mitsubishi, No. 28 at p. 2) Mitsubishi contended that like every other 
inverter-driven variable-capacity ductless OEM, Mitsubishi systems and 
components are unable to test or operate with any coil in a lab or in 
the field that is not equipped with proprietary communication protocol 
and firmware, and that evaluating their outdoor units as OUWNMs renders 
these controls and advancements completely useless. (Id.) Mitsubishi 
requested that either communicating variable-speed systems be exempted 
from the OUWNM provisions, or that specific allowances be considered to 
enable communicating variable-capacity outdoor units to be tested in a 
way that demonstrates compliance with Federal efficiency minimum 
standards. (Id.)
    DOE clarifies that the OUWNM requirements will apply to all split-
system CAC/HPs units, whether they use proprietary controls to 
communicate conditioned-space temperature and/or humidity, use a 
generic thermostat, or allow either installation approach. Also, DOE 
understands that many ductless multi-split systems and VRF systems are 
variable-speed systems that employ software that requires the outdoor 
unit to be paired with a recognized indoor unit (i.e., a pairing 
confirming system).\41\ Manufacturers of ductless multi-split systems 
and VRF systems may already have the means to test these systems with a 
generic indoor unit or may need to reprogram their outdoor units to 
allow operation with a generic indoor unit, for units using a 
refrigerant with GWP greater than 700 that are manufactured after 
January 1, 2025. While the latter option may require additional 
software rework, this reprogramming would require limited engineering 
hours to implement, such that DOE does not consider it to be burdensome 
to manufacturers. In response to GE's proposal to allow outdoor-unit-
only listings for such systems based on the lowest-performing system 
combination for the outdoor coil, and Mitsubishi's request for such 
systems to be exempted from the OUWNM provisions or given special

[[Page 1245]]

allowances, DOE notes that neither approach provides confirmation that 
a given outdoor unit could not be field paired with a nonproprietary 
indoor unit(s). Therefore, to maintain consistency across all split-
system CAC/HPs, irrespective of the control type, DOE is exempting 
neither pairing confirming variable-speed systems nor variable-speed 
communicating systems from the OUWNM provisions, nor allowing either 
category of outdoor units to be rated based on its lowest-performing 
combination.
---------------------------------------------------------------------------

    \41\ While the term used by commenters to refer to such systems 
is ``communicating,'' DOE notes that the current test procedure uses 
this term differently. Specifically, ``communicating,'' per the 
current test procedure, refers to the ability of the system to 
communicate in-space temperature with both the outdoor and indoor 
units, instead of communication between the indoor and outdoor 
units. DOE also notes that neither the AHRI test standards (210/240 
and 1600) nor the test procedure being finalized in this rule use 
the term ``communicating.'' To prevent confusion, DOE is referring 
to these systems as ``pairing confirming systems.''
---------------------------------------------------------------------------

(6) Service Coil Definition
    GE Appliances and Mitsubishi requested revision to the ``service 
coil'' definition (see 10 CFR appendix M1, section 1.2) to also include 
integrated indoor blowers within the definition's scope. (GE 
Appliances, No. 37 at pp. 1-3; Mitsubishi, No. 28 at p. 2)
[GRAPHIC] [TIFF OMITTED] TR07JA25.001


[[Page 1246]]


[GRAPHIC] [TIFF OMITTED] TR07JA25.002

    GE Appliances contended that revising the definition of service 
coil to account for DFS systems is essential to protect consumers who 
have recently installed DFS systems using R-410A refrigerant and that 
without these revisions, indoor replacement units to repair DFS systems 
during their expected useful life may be limited, and consumers may be 
required to replace entire systems instead of merely components. (Id.) 
GE further commented that if DFS systems are not able to have indoor 
coil replacements, there is a risk of significant negative consumer 
sentiment toward DFS systems. (Id.)
    Mitsubishi asserted that circumstances where full replacement of 
ductless indoor units would be significantly less costly than field 
replacement of individual parts would needlessly impact the pocketbooks 
of homeowners and consume scarce technician labor hours. (Mitsubishi, 
No. 28 at p. 2) Mitsubishi recommended a carve out or alteration of the 
current definition of service coil to allow ductless indoor units to be 
sold for purposes of service, as it would remedy this concern and be 
better aligned with the EPA Technology Transitions rule and guidance. 
(Id.)
    DOE concurs with GE Appliances that mini-split, multi-split, and 
VRF systems have become more prevalent in the residential air-
conditioning market. As noted by GE Appliances, the current service 
coil definition does not include indoor units that have integrated 
indoor blowers. DOE also notes that the service coil definition in AHRI 
210/240-2024 and AHRI 1600-2024, the industry standards DOE is 
referencing in this final rule, also do not include integrated indoor 
blowers within the service coil definition. Both appendix M1 (see 
section 1.2 of appendix M1) and the AHRI standards define ``indoor 
unit'', which includes integrated blowers within the definition's 
scope. The indoor unit definition in Appendix M1 also explicitly notes 
that a service coil is not an indoor unit. In relevance to the EPA 
rule, the labelling requirements at 40 CFR 84.58(b) clarify the 
installation allowances of indoor units. Specifically, 40 CFR 84.58(b) 
notes that, after January 1, 2025, specified components intended for 
use with banned refrigerants shall have the label ``For servicing 
existing equipment only'' attached. Any indoor units that are intended 
to be used with banned refrigerants (such as R-410A) fall within the 
scope of specified components and under the aforementioned regulatory 
provisions under the EPA's rule would need to have this label attached.
    As was noted in the previous section of this notice, the CAC/HP 
definition in 10 CFR 430.2 includes a requirement that indoor units 
sold alone be rated as part of a combination. Specifically, the 
definition states ``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).'' Such 
indoor units may be distributed by indoor coil manufacturers (``ICMs'') 
which, as defined in Appendix M1, manufacture indoor units but do not 
manufacture single-package units or outdoor units. They may also be 
distributed in commerce alone and not as part of a combination by non-
ICMs for the replacement market. For an indoor unit intended only for 
replacement in an existing system and which is no longer distributed in 
commerce for installation as a combination, as would be the case for an 
existing system that uses a refrigerant banned by EPA, the requirement 
in table 1 of 10 CFR 429.16(a) for the indoor unit to be rated as part 
of a system would still apply even though the indoor unit is no longer 
being distributed in commerce as part of a combination. This rating 
requirement would apply regardless of whether the manufacturer of the 
indoor unit is an ICM. If the indoor unit uses a refrigerant allowed by 
EPA only for component replacement (e.g., R-410A), the rating for such 
a unit would be based on a combination using that refrigerant, and per 
EPA regulations could not be distributed in commerce as a combination. 
However, this does not imply that the indoor unit cannot be rated, nor 
that the entire system would have to be replaced, as suggested by GE. 
DOE notes further that any such rating

[[Page 1247]]

for the indoor unit must be compliant with current standards, and that 
any indoor units distributed in commerce for use in a system that uses 
a refrigerant subject to the EPA ban would need to have been certified 
to DOE as compliant with the applicable standards as part of a 
combination before January 1, 2025.
(7) Space-Constrained Systems
    NCP commented that it performed analysis, testing, and simulations 
of through-the-wall space-constrained R-410A systems to evaluate 
available options to meet the proposed OUWNM requirement for applicable 
outdoor condensing units. (NCP, No. 27 at p. 2) NCP contended that the 
results of this testing \42\ indicated that its space-constrained 
outdoor condensing units would not meet applicable minimum efficiency 
requirements when rated using a generic indoor coil as specified by the 
OUWNM requirements. (Id.) NCP asserted that it was not aware of any 
space-constrained outdoor condensing units from other manufacturers 
that could meet efficiency requirements when rated as an OUWNM. (Id.) 
NCP asserted that the OUWNM requirements in DOE's proposed rule would 
effectively prohibit any space-constrained R-410A outdoor condensing 
unit after January 1, 2026, and leave manufacturers with stranded 
inventory. (NCP, No. 27 at p. 2) NCP contended that occupants of 
multifamily housing units with recently installed space-constrained R-
410A split systems would be left without options for service 
replacement of their outdoor condensing unit section, beyond 
installation of the entire indoor and outdoor split system. (Id.) To 
provide relief from excessive cost burdens, NCP suggested that DOE 
should include language in the final rule that coil-only ratings for 
space-constrained split-system outdoor units with R-410A are 
permissible until January 1, 2028, for units manufactured before 
January 1, 2025. (Id.) Alternatively, NCP suggested that DOE should use 
its enforcement discretion to provide additional 2-year sell through 
before OUWNM ratings are required for through-the-wall space-
constrained R-410A outdoor condensing units. (Id.)
---------------------------------------------------------------------------

    \42\ NCP shared results of its analysis in confidential exhibits 
A and B.
---------------------------------------------------------------------------

    DOE reviewed the confidential data provided by NCP for select 
outdoor unit models and agrees that the data suggests that these models 
cannot meet applicable minimum efficiency requirements when tested as 
OUWNMs. However, DOE notes that the data provided does not include 
performance data or estimates for designs with any technology 
improvements, e.g., two-stage or variable-speed compressors. Thus it is 
not clear that compliance with Federal standards is impossible for 
space-constrained OUWNMs.
    DOE further notes that NCP suggests a delay of the OUWNM 
requirement until January 1, 2028, but the need for replacement outdoor 
units would still exist after January 1, 2028, only 3 years after EPA's 
transition date for R-410A. This would suggest that NCP believes that 
space-constrained outdoor unit designs can be developed to be compliant 
with standards using the OUWNM test requirements starting on that date. 
Regarding stranded inventory, as clarified earlier in section 
III.E.6.c.1, DOE notes that the EPA rule includes a 1-year sell-through 
period that would enable any accumulated inventory to be distributed, 
beyond which any space-constrained CAC/HP outdoor units using R-410A 
would need to certify as OUWNMs. As discussed elsewhere in this final 
rule, to the extent that units are distributed in commerce as OUWNMs, 
they would be distributed as a different basic model as compared to 
distribution in commerce when paired with an indoor unit.
    For these reasons, DOE has determined that there is not sufficient 
justification for delaying the OUWNM requirements for R-410A space-
constrained CAC/HP products. Additionally, as discussed previously in 
this section, the timing of permitted installations of R-410A systems 
and components is based on EPA's refrigerant regulations. DOE is 
clarifying the applicability of the test procedure requirements in this 
final rule to allow for component installations consistent with EPA's 
requirements.
(8) Representativeness of Paired Indoor Coil
    Rheem questioned the appropriateness of the indoor coil 
specifications currently required for OUWNM testing. (Rheem, No. 34 at 
pp. 2-3) Rheem provided historical background of DOE's OUWNM provisions 
by citing language from past rulemaking notices, noting some of the 
following key points:
    (1) DOE first proposed an NGIFS for rating and certifying the 
performance of outdoor units designed for R-22 in the November 9, 2015 
SNOPR, where DOE proposed an upper limit on NGIFS equal to 1.15. 80 FR 
69278, 69404.
    (2) DOE indicated that its analysis supporting NGIFS values for 
OUWNM testing was based on reverse-engineered SEER 13 split systems 
(blower-coil combinations) designed for R-22. 81 FR 36992, 37010.
    (3) However, DOE set the upper limit on NGIFS at 1.0 in the June 
08, 2016 Final Rule, arguing that a lower NGIFS better reflected the 
installed base of indoor units, since the installed base also included 
10 SEER split systems. 81 FR 36992, 37010.
    (4) In the August 24, 2016 SNOPR, DOE acknowledged that legacy 
(existing) indoor units matched with no-match outdoor units would not 
always be indoor units designed for R-22, and that the NGIFS 1.0 upper 
limit did not provide a good representation of the heat transfer 
performance of indoor coils with newer designs. 81 FR 58164.
    Rheem also commented on the DOE proposal in the August 8, 2016 
SNOPR to adopt a maximum NGIFS requirement generally for testing of 
single-split coil-only systems. Because this proposal did not address 
OUWNM outdoor units and because DOE did not adopt the proposal, Rheem 
stated that it is not relevant to the OUWNM discussion. Based on the 
historical context provided from prior rules, Rheem requested DOE 
review the test provisions for OUWNMs, the definition of NGIFS, and its 
upper limit to accurately represent the current installed base of 
indoor coils with which such condensing units would be matched in the 
field. (Rheem, No. 34 at p. 3)
    DOE appreciates Rheem's comment charting the historical development 
of the OUWNM testing provisions. As noted earlier in section III.E.7 
and indicated by Rheem's comment, the current instruction at section 
2.2.e of appendix M1 requires that an OUWNM be tested using a coil-only 
indoor unit coil that has round tubes of outer diameter no less than 
0.375 inches and NGIFS of no greater than 1.0 sq in/Btu/hr. These 
indoor coil specifications were initially finalized for appendix M in 
the June 8, 2016 Final Rule and extended to appendix M1 in the January 
2017 Final Rule. 81 FR 36992, 82 FR 1426. DOE did not propose revision 
of the requirements in the April 2024 NOPR.
    In response to Rheem's comment, DOE reviewed historical data, 
starting with shipments analysis supporting the energy conservation 
standards direct final rule published on January 6, 2017 (``January 
2017 DFR''). 82 FR 1786. DOE conducted analysis to determine whether a 
substantial percentage of CAC system replacements in 2025 would occur 
in residences in which the indoor unit would have been installed prior 
to 2010, i.e., when the representative indoor unit would have been part 
of a

[[Page 1248]]

13 SEER R-22 system, consistent with DOE's initial analysis to 
establish the NGIFS requirements. To conduct this analysis, DOE used 
national impact analysis results provided in the January 2017 DFR and 
its supporting documents and spreadsheets. (See 82 FR 1786, 1822-1824) 
In this assessment, DOE considered that a portion of system 
replacements have been outdoor-unit-only installations, consistent with 
the January 2017 DFR assumptions for the percentage of installations 
involving just an outdoor unit. This factor increases the average age 
of an existing indoor unit, since, for some portion of the existing 
residences, the indoor unit would not have been replaced during the 
last outdoor unit replacement.
    The results of this analysis indicate that more than 60 percent of 
system replacements in 2025 would involve a residence where the indoor 
unit was installed before 2010. DOE also considered sensitivity of this 
analysis to differences between shipment projections made to support 
the January 2017 DFR and actual recent-year shipments and found that an 
analysis updated for recent shipment data would suggest a slightly 
higher percentage for pre-2010 indoor units. Thus, DOE concludes that 
the NGIFS limit initially established in the June 8, 2016 Final Rule is 
still representative, and DOE is not revising it in this final rule.
(9) Single Cooling Air Volume Rate
    AHRI, the CA IOUs, Carrier, and Daikin recommended that DOE retain 
the requirement to test OUWNMs with a single cooling air volume rate. 
(AHRI, No. 25 at p. 5; CA IOUs, No. 32 at pp. 2-3; Carrier, No. 29 at 
p. 4; Daikin, No. 36 at p. 2)
    AHRI recommended that the testing instructions proposed for OUWNMs 
at section 4.2 of appendix M1 also include the current regulatory 
requirement that the coil-only indoor unit has a ``single cooling air 
volume rate.'' (AHRI, No. 25 at p. 5) The CA IOUs also recommended that 
DOE retain the requirement for testing OUWNMs with a ``single cooling 
air volume rate'' in section 4.2 of the proposed revision to appendix 
M1 and include an identical requirement in section 3.2 of appendix M2. 
(CA IOUs, No. 32 at p. 2) The CA IOUs commented that they believe this 
specific requirement of a single cooling air volume rate was 
inadvertently left out of the new AHRI standards. (Id.) The CA IOUs 
reasoned that because OUWNMs are compatible with any existing air 
handler that continues to remain as the primary air-moving system after 
the originally paired outdoor unit is replaced, DOE cannot guarantee 
that such systems will have controls capable of varying airflow during 
operation and should, therefore, continue to require a single air 
volume rate. (Id.) Carrier also noted that the current appendix M1 
requirements for OUWNM testing require a single cooling air volume 
rate, and it recommended that DOE continue to require a single cooling 
air volume rate. (Carrier, No. 29 at p. 4) Daikin strongly suggested 
that DOE maintain the single airflow rate requirement for all OUWNMs, 
reasoning that OUWNMs do not include an indoor unit change and would, 
therefore, not have any enhancements, such as non-bleed expansion 
valves or blower delays, to improve cyclic performance. (Daikin, No. 36 
at p. 2)
    The current requirements at section 2.2e of appendix M1 require 
that an OUWNM be tested using a coil-only indoor unit at a single 
cooling air volume rate. DOE notes that this requirement was 
inadvertently left out of the April 2024 NOPR. DOE agrees with the 
reasoning presented by commenters advocating that this requirement be 
retained. Therefore, DOE is including language at section 4.2 of 
revised appendix M1 and section 3.2 of new appendix M2, requiring the 
use of a single cooling air volume rate when testing OUWNMs.
(10) Use of Default Degradation Coefficient for OUWNM Testing
    AHRI, the CA IOUs, and Daikin recommended that DOE use the default 
degradation coefficient of 0.25 for all OUWNMs, for both heating and 
cooling modes. (AHRI, No. 25 at p. 5; CA IOUs, No. 32 at p. 3; Daikin, 
No. 36 at p. 2)
    AHRI noted that the existing provisions for OUWNMs for degradation 
coefficient in enforcement is to use the default value (0.25), whereas 
the published versions of AHRI 210/240-2024 and AHRI 1600-2024 allow 
for testing of CD for OUWNMs. (AHRI, No. 25 at p. 5) AHRI strongly 
recommended that DOE adopt the default degradation coefficient of 0.25 
for all OUWNMs, for both heating and cooling modes. (Id.) AHRI reasoned 
that a significant portion of OUWNM units are applied in multifamily 
apartment dwelling situations, where the probability of being properly 
paired with an indoor product that can be retrofitted to have a time 
delay, or having an indoor product that is retrofitted with a non-bleed 
thermal expansion valve or an electronic expansion valve is relatively 
low (since many multifamily apartment dwelling indoor systems are 
ceiling-mount blower coil systems or wall-mount blower coil systems). 
(Id.) Therefore, AHRI contended that a substantial portion of OUWNMs 
installed in multifamily applications would not have the lower CD in 
the real world, as experienced in testing. (Id.) The CA IOUs also 
suggested that the cyclic degradation default values in proposed 
appendices M1 and M2 align with the current requirement in 10 CFR part 
429 for OUWNMs. (CA IOUs, No. 32 at p. 3) The CA IOUs noted that they 
supported the use of default values because the metering device, which 
is unknown for an OUWNM, significantly affects cyclic degradation. 
(Id.) Daikin also suggested that the default value of 0.25 be used for 
both cooling and heating degradation coefficients for OUWNMs. (Daikin, 
No. 36 at p. 2)
    As noted by commenters, the current enforcement requirement at 10 
CFR 429.134(k)(2)(ii) states that DOE will use the default cooling and 
heating degradation coefficients when testing models of OUWNMs. DOE 
agrees with the reasoning presented by commenters and notes that this 
enforcement requirement was put in place on the basis of the same 
rationale. Additionally, the requirement was intended to be adopted 
broadly for testing, not just for enforcement, as indicated in the June 
2016 Test Procedure Final Rule. 81 FR 36992, 37011. To clarify that 
this requirement also applies to testing, DOE is including provisions 
at section 4.2 of revised appendix M1 and section 3.2 of new appendix 
M2 to require that testing of OUWNMs only use the default degradation 
coefficients (0.25) for both cooling and heating modes.
8. Inlet and Outlet Duct Configurations
    Both appendix D of the AHRI 210/240-202X Draft and appendix D of 
the AHRI 1600-202X Draft define lists of clarifications/exceptions to 
their referenced version of ASHRAE Test Standard 37 (ANSI/ASHRAE 37-
2009). These clarifications/exceptions have been revised repeatedly 
throughout the version history of the AHRI 210/240 standard. In the 
April 2024 NOPR, DOE noted that both appendix D of AHRI 210/240-202X 
Draft and appendix D of AHRI 1600-202X Draft contain updates regarding 
inlet and outlet duct configurations, including the duct revisions 
investigated in RP 1581 and RP 1743 to accommodate smaller 
environmental chambers. These updates are consistent with the draft of 
an update of ANSI/ASHRAE Standard 37 (``May 2023 ASHRAE 37 Draft''). 
DOE surmised that the inclusion of these May 2023 ASHRAE 37 Draft 
updates in appendix D of the relevant AHRI drafts represented industry 
consensus, and DOE tentatively determined that the

[[Page 1249]]

updates are appropriate for CAC/HP testing. 89 FR 24206, 24231. 
Consequently, DOE proposed to incorporate by reference appendix D of 
AHRI 210/240-202X Draft at appendix M1 and to incorporate by reference 
appendix D of AHRI 1600-202X Draft at appendix M2. Id.
    DOE noted that AHRI 210/240-202X Draft and AHRI 1600-202X Draft 
reference the current version of ASHRAE Test Standard 37, ANSI/ASHRAE 
37-2009, because the May 2023 ASHRAE 37 Draft had not yet been 
finalized and published. Id. DOE further noted that it may choose to 
update its incorporation by reference to the final published version of 
the May 2023 ASHRAE 37 Draft in a future rulemaking. Id.
    DOE did not receive any comments regarding the aforementioned 
proposals in the April 2024 NOPR. AHRI 210/240-2024 and AHRI 1600-2024 
finalized the updates regarding inlet and outlet duct configurations 
without substantial change. Both standards continue to reference ANSI/
ASHRAE 37-2009 since the May 2023 ASHRAE 37 Draft has not yet been 
finalized. Therefore, consistent with the April 2024 NOPR proposal, DOE 
is incorporating by reference Appendix D of AHRI 210/240-2024 and AHRI 
1600-2024, at appendix M1 and appendix M2, respectively. DOE is also 
continuing to maintain reference to ANSI/ASHRAE 37-2009 since the May 
2023 ASHRAE 37 Draft has not yet been finalized.
9. Heat Comfort Controllers
    A heat comfort controller enables a heat pump to regulate the 
operation of the electric resistance elements such that the air 
temperature leaving the indoor section does not fall below a specified 
temperature (see section 1.2 of appendix M1).
    In the April 2024 NOPR, DOE noted that appendix M1 does not 
currently specify additional steps for calculating the HSPF2 of heat 
pumps having a heat comfort controller and having a variable-speed 
compressor. 89 FR 24206, 24231. DOE noted that AHRI 210/240-202X Draft 
and AHRI 1600-202X Draft specify additional steps for calculating the 
HSPF2 and SHORE of heat pumps having a variable-capacity compressor and 
a heat comfort controller and that these additional steps are similar 
to the additional steps for calculating the HSPF2 and SHORE of other 
system types having a heat comfort controller. Id. DOE tentatively 
determined that the inclusion of these additional steps for calculating 
HSPF2 and SHORE is appropriate for heat pumps having a variable-
capacity compressor and a heat comfort controller, because these 
provisions provide representative measures of unit operation when 
installed with heat comfort controllers. Id. Therefore, DOE proposed to 
incorporate by reference the additional steps for calculating the HSPF2 
of heat pumps having a variable-capacity compressor and a heat comfort 
controller outlined in section 11.2.2.5 of AHRI 210/240-202X Draft, at 
appendix M1. Id. Likewise, DOE proposed to incorporate by reference the 
additional steps for calculating the SHORE of heat pumps having a 
variable-capacity compressor and a heat comfort controller outlined in 
section 11.2.2.5 of AHRI 1600-202X Draft, at appendix M2. Id.
    DOE did not receive any comments regarding these proposals. AHRI 
210/240-2024 and AHRI 1600-2024 finalized the updates to the heat 
comfort controller calculations without substantial change. Therefore, 
consistent with the April 2024 NOPR proposals, DOE is incorporating by 
reference section 11.2.2.5 of AHRI 210/240-2024 and AHRI 1600-2024, at 
appendix M1 and appendix M2, respectively.

F. Long-Term Changes in the CAC Test Procedure

    The following sections discuss issues that affect the CAC/HP test 
procedure in the long term--i.e., they will be effective when new CAC/
HP standards are established in terms of the efficiency metrics SCORE 
and SHORE in appendix M2. As previously explained, these long-term 
revisions would be implemented at the new appendix M2 via incorporation 
by reference of the relevant industry consensus test procedure, AHRI 
1600-2024. DOE has reviewed AHRI 1600-2024 and has concluded that it 
satisfies the EPCA requirement that test procedures should not be 
unduly burdensome to conduct and should be representative of an average 
use cycle. (42 U.S.C. 6293(b)(3)) These long-term amendments in 
appendix M2 would alter the measured efficiency of CAC/HPs and would 
require representations in terms of new cooling and heating test 
metrics, SCORE and SHORE, respectively.
1. Power Consumption of Auxiliary Components
    AHRI 1600-202X Draft introduces SCORE and SHORE as replacements for 
the current cooling and heating performance metrics, SEER2 and HSPF2, 
used to determine the measured efficiency of CAC/HPs. Unlike SEER2 and 
HSPF2, which are seasonal efficiency metrics that don't include all 
energy consumed by the systems, these new metrics do address energy use 
of all components and operational modes, specifically including the 
standby and off mode power consumption of auxiliary components. These 
include those components discussed previously (i.e., crankcase heaters 
and indoor fans utilizing constant circulation) for both SCORE and 
SHORE, and, additionally, base pan heaters for SHORE.
    SEER2 and HSPF2 are both ratio metrics that include all calculated 
space conditioning in the numerator and all energy use associated with 
space conditioning in the denominator. In contrast, AHRI 1600-202X 
Draft includes two new quantities--Es,c (measured in watt-
hours), added to the denominator of the calculation for SCORE, meant to 
represent all auxiliary component energy usage during cooling mode 
(i.e., during both cooling conditioning hours and cooling-season 
shoulder hours, as applicable), and Es,h (also measured in 
watt-hours), added to the denominator of the calculation for SHORE, 
that is meant to represent all auxiliary component energy usage during 
heating mode (i.e., during both heating conditioning hours and heating-
season shoulder hours, as applicable). Table 14 and table 16 of AHRI 
1600-202X Draft outline instructions for determining each component's 
number of standby power operating hours in cooling mode and heating 
modes, and appendix G of AHRI 1600-202X Draft \43\ outlines 
instructions for determining the average power of all auxiliary 
components considered in the calculations of either Es,c or 
Es,h.
---------------------------------------------------------------------------

    \43\ In the April 2024 NOPR, DOE incorrectly referred to 
appendix H of AHRI 1600-202X Draft as the appendix regarding the 
determination of average power of auxiliary components (see 89 FR 
24206, 24236). This was a typographical error, since the appendix 
regarding the determination of average power of auxiliary components 
is at appendix G of AHRI 1600-202X Draft.
---------------------------------------------------------------------------

    In the April 2024 NOPR, DOE tentatively concluded that the 
respective inclusions of Es,c and Es,h into the 
calculations of the new cooling and heating performance metrics, SCORE 
and SHORE, represent industry consensus regarding whether to reflect 
the power consumption of auxiliary components in the efficiency metrics 
for CAC/HPs. 89 FR 24206, 24236. DOE tentatively determined that 
inclusion of the energy consumed by auxiliary components in the 
efficiency metrics for CAC/HPs would result in more representative 
measures of efficiency. Id. Therefore, DOE proposed to incorporate by 
reference the new cooling and heating performance metrics, SCORE and 
SHORE, as

[[Page 1250]]

included in AHRI 1600-202X Draft, and the associated provisions 
regarding the standby and off mode power consumption of auxiliary 
components, in appendix M2. Id.
    DOE did not receive any comments regarding this proposal. AHRI 
1600-2024 finalized the new cooling and heating performance metrics, 
SCORE and SHORE, and the associated provisions regarding the standby 
and off mode power consumption of auxiliary components, without 
substantial change. Therefore, consistent with the April 2024 NOPR 
proposal, DOE is incorporating by reference AHRI 1600-2024, and 
adopting the SCORE and SHORE metrics, and the associated provisions 
regarding the standby and off mode power consumption of auxiliary 
components, at appendix M2.
2. Impact of Defrost on Performance
    In order for HPs to undergo a defrost cycle, which aims to remove 
the moisture collected as frost on the outdoor coil, an HP temporarily 
switches to cooling mode operation. This enables an HP to transfer heat 
from the indoor coil to the outdoor coil, thus providing the heat 
needed to warm the coil above freezing temperature and melt the frost.
    In the April 2024 NOPR, DOE explained how AHRI 1600-202X Draft 
introduces two changes to the treatment of defrost performance of CAC/
HPs: (1) it simplifies the demand defrost credit by uniformly applying 
a 3-percent increase to the SHORE rating for all HPs equipped with 
demand defrost, and (2) it accounts for the use of supplementary heat 
during defrost using a new defrost heat and defrost overrun debits. 89 
FR 24206, 24236-24238. DOE surmised that AHRI 1600-202X Draft's 
introduction of the simplified demand defrost credit in AHRI 1600-202X 
Draft represented industry consensus regarding improvements to the 
accuracy of the credit, incentives for more efficient defrost control 
strategies, and more accurate representations of modern defrost control 
technologies in the test procedure. 89 FR 24206, 24237. DOE tentatively 
determined that a simplified demand defrost credit would disincentivize 
unnecessary early defrosts (90 minutes after the termination of the 
prior defrost cycle), accurately represent defrost energy use while 
limiting test burden, and consequently allow for more advanced and 
efficient defrost control strategies. Similarly, DOE tentatively 
determined that the defrost heat and defrost overrun debits associated 
with accounting for use of supplementary heat during defrost 
represented industry consensus and that these debits result in more 
representative CAC/HP efficiencies for models with supplementary heat 
during defrost. Therefore, DOE proposed to incorporate by reference at 
appendix M2 the defrost-related provisions from AHRI 1600-202X Draft.
    In response to DOE's proposal, the Joint Advocates stated that they 
acknowledge the improvements made to the treatment of defrost in the 
proposed appendix M2. (Joint Advocates, No. 30 at p. 4) However, the 
Joint Advocates also commented that, by assigning the defrost credit 
and debits based on a yes or no framework, the proposed appendix M2 
does not capture the true differentiation that exists between defrost 
controls. (Id.) The Joint Advocates encouraged DOE to collect 
information about defrost mechanisms and consider how defrost impact 
may be better represented in a future update to the CAC/HP Federal test 
procedures. (Id.)
    In response to the Joint Advocates, DOE notes that it will continue 
to review the defrost credit and debits and may propose changes once 
more information is made available. However, since little or no 
information is currently available and the defrost credit and debits 
represent industry consensus, DOE is adopting the defrost credit and 
debits without modification, as proposed.
    DOE did not receive any other comments regarding this proposal. 
AHRI 1600-2024 finalized the defrost related provisions discussed in 
the aforementioned paragraphs, without substantial change. Therefore, 
consistent with the April 2024 NOPR proposal, DOE is incorporating by 
reference AHRI 1600-2024 and adopting the defrost-related provisions at 
appendix M2.
3. Updates to Building Load Lines and Temperature Bin Hours
    In the April 2024 NOPR, DOE discussed several changes introduced in 
AHRI 1600-202X Draft with regard to the building load lines and 
temperature bin hours used when determining the new seasonal metrics, 
SCORE and SHORE. 89 FR 24206, 24238-24239. Specifically, DOE noted that 
(1) the new metrics use total hours instead of fractional hours; (2) 
total hours are split into conditioning hours and shoulder hours, with 
the cooling conditioning hours and cooling-season shoulder hours for 
each bin listed in table 15 of AHRI 1600-202X Draft \44\ and the 
heating conditioning hours and heating-season shoulder hours for each 
bin listed in table 18 of AHRI 1600-202X Draft; \45\ and (3) the 
cooling and heating building load lines were revised based on PNNL 
EnergyPlus simulations. Id.
---------------------------------------------------------------------------

    \44\ In the relevant April 2024 NOPR preamble discussion, there 
were instances where DOE mistakenly referred to section table 13 of 
AHRI 1600-202X Draft. This has been corrected to table 15 of AHRI 
1600-202X Draft in this final rule preamble discussion.
    \45\ In the relevant April 2024 NOPR preamble discussion, there 
were instances where DOE mistakenly referred to table 15 of AHRI 
1600-202X Draft. This has been corrected to table 18 of AHRI 1600-
202X Draft in this final rule preamble discussion.
---------------------------------------------------------------------------

    DOE surmised that the switch from fractional hours to total hours, 
the associated values of the conditioning hours and shoulder hours, and 
changes in the building load line equations represented industry 
consensus for calculations of the new cooling and heating performance 
metrics, SCORE and SHORE. 89 FR 24206, 24239. DOE proposed to 
incorporate by reference the new cooling conditioning hours, cooling-
season shoulder hours, heating conditioning hours, heating-season 
shoulder hours, and the updated building load line equations in AHRI 
1600-202X Draft, at appendix M2. Id.
    In response to DOE's proposal, Copeland asserted that, while a 
differentiated load line for variable-speed systems is indeed 
consistent with AHRI 1600-2024, it may no longer be representative of 
how various compressor-staging technologies are sized and installed in 
the field by the time ratings in terms of SCORE and SHORE take effect. 
(Copeland, No. 31 at pp. 2-3) Copeland pointed to a recent (February 
2024) revision of the capacity range sizing recommendations for two-
stage systems in the third edition of Air Conditioning Contractors of 
America's (``ACCA's'') Manual S[supreg] \46\ as the source of its 
concern, remarking that these revisions were not available when the 
AHRI Standards Technical Committee discussions regarding AHRI 210/240-
2024 and AHRI 1600-2024 took place. (Id.)
---------------------------------------------------------------------------

    \46\ To access the normative section of the third edition of the 
ACCA Manual S, see www.acca.org/standards/technical-manuals/manual-s.
---------------------------------------------------------------------------

    Copeland also noted that the slope factors used to differentiate 
the heating building load line for variable-speed HPs from single-stage 
and two-stage HPs in the current appendix M1 (i.e., C and 
CVS) were derived from an Oak Ridge National Laboratory 
(``ORNL'') analysis \47\ and influenced by the capacity range sizing 
recommendations in the second edition of ACCA's Manual S. (Copeland, 
No. 31 at pp. 2-3) Copeland commented that the second

[[Page 1251]]

edition of ACCA's Manual S allowed a range of capacity from 0.9 to 1.15 
for single-stage and two-stage HPs and 0.9 to 1.3 for variable-speed 
HPs, which, if used to calculate a size adjustment factor for variable-
speed HPs, equals 1.07 (by dividing (0.9 + 1.3) by (0.9 + 1.15)). (Id.) 
Taking this same approach with the third edition of ACCA's Manual S, 
which allows oversizing for two-stage HPs up to 1.25 and up to 1.3 for 
variable-speed HPs, Copeland stated that the size adjustment factor for 
variable-speed HPs would be 1.02 (by dividing (0.9 + 1.3) by (0.9 + 
1.25)) instead of 1.07. (Id.)
---------------------------------------------------------------------------

    \47\ See www.regulations.gov/document/EERE-2016-BT-TP-0029-0002.
---------------------------------------------------------------------------

    Rather than adjusting the values of C and CVS, however, 
Copeland encouraged DOE to consider eliminating the differentiated load 
line altogether, since a building's load calculation is not dependent 
on the compression technology of a heating and/or cooling system. 
(Copeland, No. 31 at pp. 2-3) Copeland also commented that it could not 
find any field data to support the idea that technicians vary 
oversizing practices based on compression technologies. Copeland 
asserted it is more likely that technicians calculate the load of the 
building and then select the next-larger capacity an OEM has available 
in a good, better, best offering when presenting quotes to homeowners. 
(Id.)
    In response to Copeland's comment encouraging DOE to consider 
eliminating the differentiated load line altogether, DOE notes that 
similar concerns were raised and addressed in the previous CAC/HP final 
rule, published by DOE on January 5, 2017 (``January 2017 Final 
Rule''). 82 FR 1426. In the January 2017 Final Rule, DOE noted that the 
incorporation of differentiated slope factors does not suggest any 
difference in building load when using different technology. 82 FR 
1426, 1456. Rather, the slope factor simply represents the ratio of 
building load to heat pump capacity. Id. DOE acknowledged that 
variable-speed products are slightly more oversized in comparison to 
the building heating load than are single-speed and two-stage products. 
Id. Keeping the building load constant and increasing the variable-
speed HP capacity reduces the building load/capacity ratio; hence DOE 
selected a lower slope factor (i.e., CVS, equal to 1.07) for 
variable-speed HPs as compared to the slope factor for single-stage and 
two-stage HPs (i.e., C, equal to 1.15). Id. In the absence of robust 
data showing average load/capacity ratios for different products, DOE 
based its building load factors on ACCA's Manual S recommendations, at 
the time using the second edition. The topic of a differentiated 
building load line for variable-speed units was also discussed during 
the development of the AHRI 210/240 and 1600 standards, and consensus 
was formed that it was appropriate to retain the differentiated line. 
Notably, both AHRI 210/240-2024 and AHRI 1600-2024 include a 
differentiated building load line for variable-speed units.
    In response to Copeland's comment, DOE notes that additional 
changes to the capacity range sizing recommendations were made in the 
third edition of ACCA's Manual S that were not mentioned in Copeland's 
comment. Specifically, the minimum capacity factor recommended for 
variable-speed heat pumps was increased from 0.9 in the second edition 
of ACCA's Manual S to 1.0 in the third edition of ACCA's Manual S.\48\ 
Incorporating this change into the approach taken by Copeland (as 
described in the preceding paragraphs), the size adjustment factor for 
variable-speed HPs as compared with two-stage heat pumps would remain 
1.07 (by dividing (1 + 1.3) by (0.9 + 1.25)). DOE agrees that a future 
revisit of these issues, taking into consideration the revision to 
Manual S and any new data that could be collected to shed light on 
potential sizing differences, and allowing for a robust discussion of 
the issues among relevant stakeholders, may be appropriate when the 
AHRI test standards and DOE test procedure undergo amendments in 
future. However, DOE notes the committee consensus for retaining the 
1.07 factor in the test standards, as reflected in AHRI 1600-2024, and 
is finalizing the DOE test procedure with this factor in this document.
---------------------------------------------------------------------------

    \48\ See table N1.16.2.4 in the normative section of the third 
edition of ACCA's Manual S, available here: www.acca.org/standards/technical-manuals/manual-s.
---------------------------------------------------------------------------

    AHRI 1600-2024 finalized the updates to the building load lines and 
temperature bin hours, without substantial change from AHRI 1600-202X 
Draft. Therefore, consistent with the April 2024 NOPR proposal, DOE is 
incorporating by reference AHRI 1600-2024 and adopting the associated 
building load lines and temperature bin hours, at appendix M2. DOE is 
also clarifying that representations of SHORE made using the ``Cold 
Climate Average'' heating conditioning hours and shoulder season hours 
in table 18 of AHRI 1600-2024 are optional.
4. Default Fan Power Coefficients for Coil-Only Systems
    Coil-only air conditioners are matched split systems consisting of 
a condensing unit and indoor coil 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/HP 
combinations do not include a designated air mover to circulate air, 
the DOE test procedures prescribe default values for power input and 
heat output to represent the furnace fan with which the indoor coil 
would be paired in a field installation. The default values are equal 
to the measured airflow rate (in scfm) multiplied by a defined 
coefficient (expressed in Watts (``W'') per 1,000 scfm (``W/1,000 
scfm'') for fan power, and Btu/h per 1,000 scfm (``Btu/h/1,000 scfm'') 
for fan heat), hereafter referred to as the ``default fan power 
coefficient'' and ``default fan heat coefficient.'' 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 (e.g., the equations 
for mobile home or space-constrained are different than for 
``conventional'' non-mobile home and non-space-constrained, and the 
equations for single-stage are different than for two-stage and 
variable speed).\49\ See, e.g., appendix M1, section 3.3. For single-
stage coil-only units installed in mobile homes and for single-stage 
space-constrained systems, appendix M1 defines a default fan power 
coefficient of 406 W/1,000 scfm and a default fan heat coefficient of 
1,385 Btu/h/1,000 scfm. See, e.g., appendix M1, section 3.3.d. For 
single-stage 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/1,000 scfm and a default fan 
heat coefficient of 1,505 Btu/h/1,000

[[Page 1252]]

scfm. See, e.g., appendix M1, section 3.3.e.
---------------------------------------------------------------------------

    \49\ The different default fan power and default fan heat 
coefficients for mobile-home and space-constrained systems as 
compared to conventional systems reflect the lower duct pressure 
drop expected for such systems in field operation--the lower values 
are consistent with the lower ESP levels required in testing of 
blower-coil systems intended for mobile home and spaced-constrained 
applications (see table 4 of appendix M1).
---------------------------------------------------------------------------

    In addition to the aforementioned default fan powers for single-
stage coil-only systems, which reflect full-load operation, appendix M1 
defines lower-load default fan powers at a reduced air volume rate of 
75 percent for two-stage and variable-speed coil-only systems. Appendix 
M1 then uses these full-load and lower-load default fan powers to 
interpolate default fan power coefficients and default fan heat 
coefficients for the full-load and part-load tests, depending on the 
air volume rate used for each test expressed as a percentage of the 
cooling full-load air volume rate (``%FLAVR''). See, e.g., appendix M1, 
section 3.3, equations for DFPCMHSC and DFPCC. 
Appendix M1 interpolates the default fan power coefficient for two-
stage and variable speed coil-only units installed in mobile homes and 
for two-stage and variable-speed space-constrained coil-only systems 
(``DFPCMHSC''), using assumptions for full-load default fan 
power at 406 W (i.e., the same as for single-stage systems) and a 
lower-load default fan power at a reduced air volume rate of 75 
percent, at 308 W. For ``conventional'' non-mobile-home and non-space-
constrained two-stage and variable-speed systems, appendix M1 
interpolates the default fan power coefficient (``DFPCC'') 
using assumptions for full-load default fan power at 441 W (i.e., the 
same as for single-stage systems) and a lower-load default fan power at 
a reduced air volume rate of 75 percent, at 335 W. The default fan 
power values used in the determination of the default fan power 
coefficients were a result of empirical analysis presented by DOE in 
the October 2022 Final Rule. (See 87 FR 64550, 64555-64559).
    In the April 2024 NOPR, DOE noted that AHRI 1600-202X Draft defines 
revised lower-load default fan powers at a reduced air volume rate of 
65 percent (rather than 75 percent) for two-stage and variable-speed 
coil-only systems and updates the default fan power values used in each 
interpolation to better reflect the fan power values used by coil-only 
systems today (on average). 89 FR 24206, 24239-24240. AHRI 1600-202X 
Draft also moves mobile home systems from the default fan power 
coefficient equation for space-constrained systems to the equation for 
``conventional'' non-space-constrained systems, because insufficient 
evidence was presented to the AHRI Standards Technical Committee to 
justify that default fan power coefficients for mobile home systems 
should be different from ``conventional'' systems. Therefore, solely 
for space-constrained coil-only systems, AHRI 1600-202X Draft uses a 
full-load default fan power of 293 W and a lower-load default fan power 
of 135 W in the default fan power coefficient interpolation 
(``DFPCSC''). 89 FR 24206, 24239-24240. For non-space-
constrained coil-only systems, AHRI 1600-202X Draft uses a full-load 
default fan power of 346 W and a lower-load default fan power of 159 W 
in the default fan power coefficient interpolation 
(``DFPCNSC''). Id. All default fan powers are lower than 
those used in the calculation of DFPCMHSC and 
DFPCC in appendix M1.
    DOE surmised that the new equations for default fan power 
coefficients and default fan heat coefficients (and their reduced full-
load default fan powers and their reduced lower-load default fan powers 
at a reduced air volume rate of 65 percent) in AHRI 1600-202X Draft 
represented industry consensus regarding the assumed power input and 
heat output of an average furnace fan or modular blower with which the 
test procedure assumes the indoor coil is paired in a field 
installation. Id. DOE tentatively determined that the reduced full-load 
and low-load default fan powers more accurately reflected the average 
design of the current installed base for blowers paired with coil-only 
CAC/HP installations, which increasingly use more efficient fan motors 
(with lower wattages). Id. DOE also tentatively determined that the 
reduced air volume rate more accurately reflected the average low-load 
air volume rate of the currently installed base for blowers paired with 
coil-only CAC/HP installations. Id. Therefore, DOE proposed to 
incorporate by reference the default fan power coefficient equations 
and default fan heat coefficient equations, and associated default fan 
powers used to interpolate such coefficients, in AHRI 1600-202X Draft, 
at appendix M2. Id.
    DOE did not receive any comments regarding this proposal. AHRI 
1600-2024 finalized the changes to the default fan power coefficients 
for coil-only systems, without change. Therefore, consistent with the 
April 2024 NOPR proposal, DOE is incorporating by reference AHRI 1600-
2024 and the associated provisions for default fan power coefficients, 
at appendix M2.
5. Airflow Limits To Address Inadequate Dehumidification
    In the April 2024 NOPR, DOE explained that, to address adequate 
dehumidification in hot and warm, humid climates, AHRI 1600-202X Draft 
established new airflow limits for the cooling mode tests to avoid high 
sensible heat ratios. 89 FR 24206, 24240. Specifically, section 6.1.5.2 
of AHRI 1600-202X Draft sets a maximum airflow limit at 37.5 scfm per 
1000 Btu/h (i.e., 450 cubic feet per minute (``cfm'') per ton of 
capacity) for cooling full airflow. Id. Additionally, section 6.1.5.3 
of AHRI 1600-202X Draft sets a maximum airflow limit at 50 scfm per 
1,000 Btu/h (i.e., 600 cfm per ton of capacity) for cooling low 
airflow. Id. Should the cooling full airflow or cooling low airflow 
specified by the manufacturer exceed these limits, AHRI 1600-202X Draft 
requires that airflows be reduced to meet these limits for testing. Id.
    In the April 2024 NOPR, DOE surmised that the addition and 
selection of specific cooling airflow limits in AHRI 1600-202X Draft 
represented industry consensus regarding the issue of inadequate 
dehumidification. 89 FR 24206, 24240. DOE tentatively determined that 
such airflow limits were appropriate to ensure that CAC/HPs provide 
adequate dehumidification during cooling mode operation and, therefore, 
DOE proposed to incorporate by reference the cooling full airflow and 
cooling low airflow limits specified in the AHRI 1600-202X Draft, at 
appendix M2. Id.
    DOE did not receive any comments regarding this proposal. AHRI 
1600-2024 finalized the cooling full airflow and cooling low airflow 
limits without change. Therefore, consistent with the April 2024 NOPR, 
DOE is incorporating by reference AHRI 1600-2024 and the associated 
airflow limits at appendix M2.

G. General Comments Received in Response to the April 2024 NOPR

    In response to the April 2024 NOPR, DOE received several general 
comments not specific to any one test procedure provision. This section 
discusses those general comments received.
    The Joint Advocates commented that before appendix M2 is enforced, 
DOE should encourage manufacturers to optionally rate their systems 
using SCORE and SHORE, i.e., the appendix M2 energy efficiency metrics. 
(Joint Advocates, No. 30 at p. 1) The Joint Advocates commented that 
such ratings would allow DOE to do an appropriate crosswalk from SEER2 
to SCORE, and HSPF2 to SHORE, to support the next round of CAC/HP 
standards rulemaking. (Id.) As discussed in section II of this 
document, use of appendix M2 would not be required until the compliance 
date of amended energy conservation standards denominated in terms of 
SCORE and SHORE, should DOE adopt such standards. However,

[[Page 1253]]

manufacturers may choose to make optional representations based on the 
metrics in appendix M2 and are encouraged to provide any test data to 
DOE to help support an analysis of the crosswalk of the energy 
efficiency metrics from appendix M1 to appendix M2.
    Additionally, the Joint Advocates commented that the bin method 
used to calculate HSPF2 and SHORE assumes that an HP will provide as 
much capacity as possible and resistance heat will meet the remaining 
building load. (Joint Advocates, No. 30 at p. 4) However, the Joint 
Advocates asserted that control logic will ultimately determine the 
relative operation of these heat sources, which may not fit with the 
bin calculation method assumption described. (Id.) The Joint Advocates 
stated that, in the case that an HP uses more resistance heat than 
assumed by the bin calculation method, a lower efficiency would be 
observed in the field than the efficiency rated for an HP; 
subsequently, the Joint Advocates encouraged DOE to consider this 
aspect of the CAC/HP Federal test procedure in a future rulemaking. 
(Id.)
    In response to the Joint Advocates' comment, at this time DOE has 
not determined an approach to account for the controls of the heat pump 
working in tandem with electric resistance heat, and is not adopting 
such an approach in this final rule. DOE notes that it may consider 
such an approach in the future.

H. Represented Values

    In the following sections, DOE discusses requirements regarding 
represented values. To the extent that DOE is amending the requirements 
specified in 10 CFR part 429 regarding representations of CAC/HPs, such 
amendments to 10 CFR part 429, if made final, would be required 
starting 180 days after publication in the Federal Register of this 
final rule. Prior to 180 days after publication in the Federal Register 
of this final rule, the current requirements would apply. However, 
manufacturers would be permitted to choose between using the current or 
new requirements for a period between 30 days and 180 days after 
publication in the Federal Register of this test procedure final rule.
1. Represented Values for the Federal Trade Commission
    As described in a final rule regarding EnergyGuide labels published 
on October 12, 2022, the Federal Trade Commission (``FTC'') is 
responsible for periodical updates to energy labeling for major home 
appliances and other consumer products, including CAC/HPs, to help 
consumers compare competing models. 87 FR 61465, 61466. Among other 
disclosures, EnergyGuide labels for CAC/HPs include estimated annual 
energy costs for both cooling and heating, which are based on the 
represented values for each basic model's efficiencies (SEER2 and 
HSPF2, as applicable), cooling capacities, and estimates for cooling 
load hours (``CLH'') and heating load hours (``HLH'') in a year. CLH 
and HLH can be thought of as the hours of run time at full capacity 
required to provide seasonal conditioning (in Btu) as calculated in the 
test procedure to determine seasonal efficiencies. Currently, the FTC 
uses 1,000 and 1,572 hours as estimates for CLH and HLH, respectively, 
for all ratings of CAC/HP basic models.\50\
---------------------------------------------------------------------------

    \50\ See table 21 of appendix M1 for the current CLH and HLH 
estimates used for rating values.
---------------------------------------------------------------------------

    In the April 2024 NOPR, DOE proposed to retain the current CLH and 
HLH estimates in appendix M1, for use in conjunction with SEER2 and 
HSPF2 representations. 89 FR 24206, 24242-24243.
    For appendix M2, DOE proposed new estimates for CLH and HLH for use 
in conjunction with the proposed appendix M2 efficiency metrics, SCORE 
and SHORE. 89 FR 24206, 24243. DOE noted that unlike SEER2 and HSPF2, 
SCORE and SHORE are integrated metrics (that include off mode and 
standby power) and use updated weather data for the United States' 
average number of conditioning and shoulder-season hours per 
temperature bin. Id. Therefore, DOE tentatively determined that the 
proposed appendix M2 required new CLH and HLH values for use by the 
FTC. Id. Specifically, DOE proposed to use 1,457 and 972 hours as 
estimates for CLH and HLH, respectively, for use in conjunction with 
SCORE and SHORE representations. Id. DOE presented step-by-step 
derivations of proposed appendix M2 CLH and HLH values in a docketed 
white paper titled ``Derivation of Proposed Appendix M2 Cooling Load 
Hours and Heating Load Hours for the Federal Trade Commission.'' \51\ 
Id.
---------------------------------------------------------------------------

    \51\ See Docket No. EERE-2022-BT-TP-0028-0019.
---------------------------------------------------------------------------

    In response to DOE's proposal, Keith Rice requested that the basis 
for these revised cooling and heating load hours (and the revised 
building load lines and temperature bin hours, discussed in section 
III.F.3 of this final rule) be well documented in a published report. 
(Keith Rice, No. 33 at p. 1) Keith Rice commented that this is 
important considering that the proposed CLH and HLH values for appendix 
M2 give a much higher weighting to cooling energy use performance 
relative to heating. (Id.)
    In response to Keith Rice, DOE notes that the CLH and HLH values 
presented in its docketed white paper were derived from the building 
load lines and temperature bin hours presented in AHRI 1600-202X Draft. 
Therefore, the report requested by Keith Rice (i.e., a report detailing 
the basis for the revised building load lines and temperature bin hours 
in AHRI 1600-2024) would need to be provided by AHRI. DOE understands 
the value of publicizing the weather analysis that forms the basis of 
the building load lines and temperature bin hours under appendix M2. 
Subsequently, DOE is willing to support AHRI in the process of 
publicizing a weather analysis report, as requested by Keith Rice.
    DOE did not receive any other comments regarding the proposal for 
new CLH and HLH values under appendix M2. Therefore, for the reasons 
discussed in the preceding paragraphs and the April 2024 NOPR, DOE is 
adopting different CLH and HLH values under appendix M2 than under the 
current appendix M1, as proposed.
    In response to DOE's proposals for CLH and HLH, Keith Rice also 
commented on the proposed calculations of annual operating costs in the 
April 2024 NOPR. (Keith Rice, No. 33 at p. 1) Keith Rice noted that the 
calculations of annual operating costs for single- versus variable-
speed HPs in the current appendix M1 and proposed appendix M2 give a 7-
percent additional energy savings benefit to variable-speed systems 
when compared on an equal rated capacity basis. (Id.) Keith Rice 
recommended, reasoning that consumers would expect that operating cost 
comparisons would be on the basis of equal house loads, that the 
existing appendix M1 and proposed appendix M2 operating cost 
calculation approaches be modified to remove the extra 7-percent 
benefit. (Id.) Keith Rice commented that, in the current appendix M1 
and proposed appendix M2, the seasonal energy performance factors 
(i.e., SEER2 and HSPF2 for appendix M1 and SCORE and SHORE for appendix 
M2) for variable-speed systems have already been boosted by the 
assumption of lower cooling and heating building loads for a given 
cooling capacity. (Id. at pp. 1-2) Subsequently, Keith Rice suggested 
that the V-factor of 0.93 in cooling mode and the lower 1.07 
Cx factor in heating mode be removed from the operating cost 
calculations for energy labeling so as to not result in a type of 
double counting

[[Page 1254]]

of energy savings benefits for variable-speed units. (Id.)
    DOE appreciates Keith Rice's comments regarding the calculations of 
annual operating costs and understands that, if a variable-speed 
product is compared with a single- or two-stage product on an apples-
to-apples basis (i.e., if both products hypothetically had the same 
represented cooling capacity and same represented SEER2 or HSPF2 under 
appendix M1 or SCORE or SHORE under appendix M2), the calculations of 
annual operating costs for a variable-speed product would yield 7-
percent lower results. However, DOE notes that this 7-percent 
difference has been used by FTC for some time--since it was adopted in 
the January 2017 Final Rule. 82 FR 1426, 1473-1475. Additionally, DOE 
notes that this 7-percent difference in annual operating costs is 
relatively marginal compared to other factors of variability, such as 
electricity rates, consumer usage patterns, etc. For these reasons, DOE 
is adopting the calculations of annual operating costs as proposed in 
the April 2024 NOPR, which are unchanged from the existing calculations 
of annual operating costs.
2. Off Mode Power
    Off mode power, PW,OFF, is a required represented value 
for all CAC/HPs, as specified in 10 CFR 429.16(a)(1). Currently, 
section 3.13 of appendix M1 includes testing instructions to determine 
off-mode power ratings for CAC/HPs. In the April 2024 NOPR, DOE 
proposed to incorporate by reference AHRI 210/240-202X Draft at 
appendix M1, and it noted that section 11.3 and appendix G of AHRI 210/
240-202X Draft \52\ include the same test instructions to determine 
PW,OFF as are present in the current appendix M1. 89 FR 
24206, 24243. Therefore, DOE proposed no changes in representation 
requirement for off mode testing when testing per appendix M1. Id.
---------------------------------------------------------------------------

    \52\ In the April 2024 NOPR preamble discussion, there were 
instances where DOE mistakenly referred to section 11.2.3 and 
appendix H of AHRI 210/240-202X Draft. This has been corrected to 
section 11.3 and appendix G of AHRI 210/240-202X Draft in this final 
rule preamble discussion.
---------------------------------------------------------------------------

    For appendix M2, DOE noted that the applicable metrics, SCORE and 
SHORE, directly incorporate off mode power consumption and as such, 
requiring representation of PW,OFF would be redundant for 
appendix M2. 89 FR 24206, 24243. Therefore, DOE proposed to clarify at 
10 CFR 429.16(a)(2) that represented values of PW,OFF are 
only required when testing in accordance with appendix M1. Id.
    Additionally, 10 CFR 429.16(b)(2)(ii) currently allows flexibility 
for manufacturers to not test each individual model/combination (or 
tested combination) for PW,OFF, but at a minimum, test at 
least one individual model/combination for PW,OFF among 
individual models/combinations with similar off mode construction. In 
the April 2024 NOPR, DOE proposed to retain this flexibility for 
testing to appendix M1. 89 FR 24206, 24243.
    For appendix M2, DOE extended similar flexibility for determining 
off mode power values P1 (off mode power in shoulder season) 
and P2 (off mode power in heating season), which are used to 
calculate the SCORE and SHORE metrics when testing to appendix M2. 89 
FR 24206, 24243. Specifically, DOE proposed at 10 CFR 429.16(b)(2)(iii) 
that when testing in accordance with appendix M2 and determining SCORE 
and SHORE, each individual model/combination is not required to be 
tested for values of P1 (off mode power in shoulder season) 
and P2 (off mode power in heating season). Id. Instead, at a 
minimum, among individual models/combinations with similar off mode 
construction (even spanning different models of outdoor units), a 
manufacturer must test at least one individual model/combination, for 
which P1 and P2 are the most consumptive. Id.
    In response to the April 2024 NOPR, Carrier, Lennox, and Rheem all 
commented in support of DOE's proposal pertaining to off mode power. 
(Carrier, No. 29 at p. 5; Lennox, No. 24 at p. 4; Rheem, No. 34 at p. 
5) Therefore, for the reasons discussed in the preceding paragraph and 
the April 2024 NOPR, DOE is adopting these changes as proposed.
3. AEDM Tolerance for SCORE and SHORE
    DOE's existing regulations allow the use of an AEDM, in lieu of 
testing, to simulate the efficiency of CAC/HPs. 10 CFR 429.16(d). For 
models certified with an AEDM, results from DOE verification tests are 
subject to certain tolerances when compared to certified ratings. 10 
CFR 429.70(e)(5)(v). The current tolerance specified for efficiency 
metrics for CAC/HPs (i.e., SEER2, HSPF2, and EER2) requires that the 
result from the DOE verification test must be greater than or equal to 
0.95 multiplied by the certified represented value.
    In the April 2024 NOPR, to maintain consistency with the existing 
efficiency metrics, DOE proposed to extend the same tolerance 
requirement to the new efficiency metrics measured per appendix M2--
EER, SCORE and SHORE. 89 FR 24206, 24243.
    DOE did not receive any comments regarding this proposal pertaining 
to AEDM tolerances on the new metrics and, therefore, DOE is adopting 
the change as proposed.
4. Removal of the AEDM Exception for Split-System CAC/HPs
    Currently, the AEDM requirements at 10 CFR 429.70(e) allow that, 
until July 1, 2024, non-space-constrained single-split-system CAC/HPs 
rated based on testing in accordance with appendix M1 are allowed to 
test a single-unit sample from 20 percent of the basic models 
distributed in commerce to validate the AEDM. On or after July 1, 2024, 
validation of the AEDM has to be based on complete testing of each 
basic model. See 10 CFR 429.70(e)(2)(i)(A). Corresponding provisions 
are also included at 10 CFR 429.16, paragraphs (b)(2)(i) and 
(c)(1)(i)(B).
    In the April 2024 NOPR, DOE noted that since amendments proposed in 
the NOPR are not expected to be finalized and made effective before 
July 1, 2024, the AEDM exception for non-space-constrained single-
split-system CAC/HPs would no longer apply at the time this rulemaking 
finalizes. 89 FR 24206, 24243. As such, DOE proposed to remove the 
date-based application of the AEDM requirement and instead clarify that 
AEDM validation for all CAC/HPs, including non-space-constrained 
single-split-system CAC/HPs, must be based on complete testing of each 
basic model. Id. DOE did not receive any comments regarding this 
proposal and is adopting the change as proposed.

I. Enforcement Provisions

1. Verifying Cut-Out and Cut-In Temperatures
    In the April 2024 NOPR, DOE proposed that for assessment and 
enforcement testing of HP models, the cut-out and cut-in temperatures 
may be verified using the test method in appendix J of AHRI 210/240-
202X Draft and AHRI 1600-202X Draft, and that if this method is 
conducted, the cut-in and cut-out temperatures determined using this 
method will be used to calculate the relevant heating metric for 
purposes of compliance. 89 FR 24206, 24243.
    AHRI 210/240-2024 and AHRI 1600-2024, the industry standards DOE is 
referencing in this final rule, finalized the relevant test method for 
determining cut-out and cut-in temperatures in appendix J without any 
substantial change. Therefore, consistent with the April 2024 NOPR, DOE 
is adding product-specific provisions at 10 CFR

[[Page 1255]]

429.134(k)--specifically, DOE is adding provisions that for assessment 
and enforcement testing of HP models, the cut-out and cut-in 
temperatures may be verified using the method in appendix J of AHRI 
210/240-2024 or AHRI 1600-2024, and that if this method is conducted, 
the cut-in and cut-out temperatures determined using this method will 
be used to calculate the relevant heating metric for purposes of 
compliance.
    In response to the April 2024 NOPR, the Joint Advocates encouraged 
DOE to adopt a requirement for manufacturers to report and certify cut-
out and cut-in temperatures for all HPs as part of a separate 
rulemaking. (Joint Advocates, No. 30 at p. 2) DOE maintains that it 
will consider certification requirements for CAC/HPs, including the 
potential requirement for certification of cut-out and cut-in 
temperatures, in a separate rulemaking, as noted in the April 2024 
NOPR. 89 FR 24206, 24243.
    Additionally, the Joint Advocates expressed uncertainty regarding 
whether DOE intended to limit cut-out and cut-in temperature 
verification to CCHPs, specifically pointing to the following sentence 
\53\ of the April 2024 NOPR preamble: ``DOE is proposing that for 
assessment and enforcement testing of CHP models, the cut-out and cut-
in temperatures may be verified using the method in appendix J and that 
if this method is conducted, the cut-in and cut-out temperatures 
determined using this method will be used to calculate the relevant 
heating metric for purposes of compliance.'' (Joint Advocates, No. 30 
at p. 2) DOE surmises that the Joint Advocates' uncertainty stems from 
the use of the acronym ``CHP'' in this sentence. DOE clarifies that 
``CHP'' stands for ``central heat pump,'' not ``cold climate heat 
pump,'' and that the cut-out and cut-in temperature verification test 
in appendix J of the respective AHRI Drafts applies to all central heat 
pumps.
---------------------------------------------------------------------------

    \53\ See 89 FR 24206, 24243.
---------------------------------------------------------------------------

2. Controls Verification Procedure
(a) DOE's Proposal
    In the April 2024 NOPR, DOE proposed to establish requirements for 
DOE's use of the CVP per appendix I of AHRI 210/240-202X Draft and AHRI 
1600-202X Draft for the purposes of assessment and enforcement testing. 
89 FR 24206, 24243-24244.
    DOE proposed that if after conducting the CVP a unit is determined 
to be either a variable-capacity compressor system; variable-capacity 
certified, single-capacity system; or variable-capacity certified, two-
capacity system, and meets the tolerances on capacity measurement (6 
percent) and efficiency \54\ (10 percent) for the applicable CVP load 
intervals, the efficiency metrics for the unit will be evaluated by 
conducting the prescribed DOE rating tests per appendix M1 or appendix 
M2 applicable to that system. 89 FR 24206, 24244. DOE clarified that 
these tests will be conducted based on the override instructions from 
the manufacturer for setting the appropriate compressor and fan speeds 
for each test. Id.
---------------------------------------------------------------------------

    \54\ EER2 and COP2 for cooling load intervals and heating load 
intervals, respectively, when tested in accordance with appendix M1, 
and EER and COP, for cooling load intervals and heating load 
intervals, respectively, when tested in accordance with appendix M2.
---------------------------------------------------------------------------

    However, if either of the full- or minimum-load CVP intervals fail 
to meet the required tolerances, and the control device allows 
monitoring and adjustment of the compressor and indoor blower speeds, 
and is the same control device used for certification and CVP 
tests,\55\ DOE proposed that it will conduct certification tests by 
setting the speeds for the tests to the average values observed during 
the corresponding failed CVP interval.\56\ 89 FR 24206, 24244. 
Alternatively, if either of the full- or minimum-load CVP intervals 
fail to meet the required tolerances, and the control device does not 
allow adjustment of the compressor and indoor blower speeds or is not 
the same control device used for certification tests, DOE proposed to 
use the average capacity and power(s) or, for CVP intervals that do not 
meet the operating tolerances and condition tolerances, time-averaged 
integrated capacity and time-averaged integrated power(s), measured 
during the CVP, in order to calculate SEER2, HSPF2, and EER2 for 
appendix M1, and SCORE, SHORE, and EER, for appendix M2. Id. For 
certification tests that do not have a corresponding CVP interval, DOE 
proposed to calculate the corresponding efficiency by adjusting the 
capacity and power, by application of a ratio to the corresponding CVP 
interval.\57\ Id.
---------------------------------------------------------------------------

    \55\ For the purpose of the CVP, ``adjustment'' means that the 
control device has the ability to make discrete adjustments, as 
required, to the compressor and indoor blower speeds without the 
need of any additional hardware or non-publicly available software.
    \56\ For tests that do not correspond to any load intervals of 
the CVP, DOE proposed to adjust the compressor speed as follows: the 
compressor speeds for tests BFull, BLow, 
H3,low, and H0Low will be set at the same 
speeds observed in the CVP load intervals associated with the 
AFull, FLow, H3Full, 
H4Full, and H1Low tests, respectively.
    \57\ As an example per the proposal, the capacity at 
BFull condition, QB,Full, will be calculated 
by the following equation: QB,Full = 
QB,Full,Certification x QCVP,A,Full 
QA,Full,Certification, where 
QB,Full,Certification is the capacity at BFull 
condition, QCVP,A,Full is the full-load interval capacity 
in cooling mode, and QA,Full,Certification is the 
capacity at Afull condition.
---------------------------------------------------------------------------

    For CHPs determined to be a variable-capacity certified, single-
capacity system or variable-capacity certified, two-capacity system 
that are certified/marketed for use with only a proprietary control 
device, DOE proposed to utilize two options: (1) contact the 
manufacturer to provide override control instructions consistent with 
the full- and, if applicable, minimum-speed operation observed during 
the CVP, to enable tests without a corresponding CVP interval to be 
conducted at the appropriate speeds; or (2) conduct the tests for 
H1Nom, H2Full, H2Low, and 
H3Low, as applicable, using the certified instructions, and 
for other certification tests, calculate the corresponding efficiency 
by adjusting the capacity and efficiency, by application of a ratio to 
the corresponding CVP interval.\58\ 89 FR 24206, 24244. Otherwise, DOE 
proposed that the same simulated thermostat low-voltage signal that 
resulted in full-speed compressor operation for the full-load intervals 
shall be used for all certification full-load tests (for variable-
capacity certified, single-capacity system or variable-capacity 
certified, two-capacity systems), and the same simulated thermostat 
low-voltage signal that resulted in low-speed compressor operation for 
the low-load intervals shall be used for all certification low-load 
tests (for variable-capacity certified, two-capacity system). Id.
---------------------------------------------------------------------------

    \58\ As an example, the capacity at HOLow condition, 
QH0,Low, will be calculated by the following equation: 
QH0,Low = QH0,Low,Certification x 
QCVP,H1,Low/QH1,Low,Certification.
---------------------------------------------------------------------------

(b) Comments Received
    In response to these proposals, DOE received several comments 
related to various aspects of the CVP's adoption for enforcement and 
assessment testing. The comments are summarized in the following 
subsections.
(1) General Feedback
    Lennox, the CA IOUs, Rheem, and GE Appliances all supported DOE's 
proposed CVP enforcement provisions utilizing the methods in the AHRI 
210/240 and AHRI 1600 standards. (Lennox, No. 24 at p. 5; CA IOUs, No. 
32 at p. 2; Rheem, No. 34 at p. 5; GE Appliances, No. 37 at p. 4) The 
CA IOUs commented that the new provisions in AHRI 210/240 will help 
consumers realize that heat pumps are an efficient means for space 
heating and cooling. (CA IOUs, No. 32 at p. 2)
    AHRI pointed out the differences between the CVP outlined in AHRI 
210/

[[Page 1256]]

240 and AHRI 1600, and the CVP outlined in the ENERGY STAR[supreg] 
Version 6.1 (``EPA Energy Star CVP'') Specifications for CACs and Air-
Source Heat Pumps (``ASHPs''),\59\ which are shown in table III.1. 
(AHRI, No. 25 at pp. 8-9)
---------------------------------------------------------------------------

    \59\ See: www.energystar.gov/sites/default/files/asset/document/ENERGY%20STAR%20Version%206.1%20Central%20Air%20Conditioner%20and%20Heat%20Pump%20Final%20Specification%20%28Rev.%20January%20%202022%29.pdf.

                     Table III--1 Summary of CVP in AHRI 210/240 and the EPA Energy Star CVP
                                            [AHRI, No. 25 at pp. 8-9]
----------------------------------------------------------------------------------------------------------------
                                                       Test segments   Test duration for
           Test type              Test segments CAC         CHP               CAC          Test duration for CHP
----------------------------------------------------------------------------------------------------------------
AHRI 210/240 and AHRI 1600--    3...................               6  9-19 hours.........  18-38 hours.
 Appendix I.
EPA Energy Star CVP...........  None................               1  None...............  Up to 2 hours.
----------------------------------------------------------------------------------------------------------------

    Similarly, LG commented that even though the Energy Star CVP is 
used to certify ENERGY STAR CCHPs, DOE's Cold Climate Heat Pump 
Technology Challenge (``DOE CCHP Tech Challenge'') \60\ implemented a 
``Min/Mild'' CVP test.\61\ (LG, No. 38 at p. 3) LG suggested that the 
presence of multiple CVPs to certify identical products would place 
undue test burden on manufacturers, and DOE should incorporate the 
``Min/Mild'' CVP in their CVP enforcement provisions, rather than going 
with the CVP outlined in the AHRI 210/240 and 1600 standards. (Id.)
---------------------------------------------------------------------------

    \60\ On May 19, 2021, DOE, in conjunction with EPA and NRCan, 
announced the DOE CCHP Tech Challenge as part of the Energy, 
Emissions, and Equity (``E3'') Initiative. The specification of the 
DOE CCHP Tech Challenge is available at https://www.energy.gov/eere/buildings/cchp-technology-challenge-specifications.
    \61\ The ``Min/Mild'' test is a load-based test conducted at 
outdoor conditions of 47 [deg]F dry bulb temperature, and 43 [deg]F 
wet bulb temperature, and indoor conditions of 70 [deg]F dry bulb 
temperature and 60 [deg]F wet bulb temperature, in order to validate 
the minimum capacity (at 47 [deg]F outdoor dry bulb temperature) of 
CCHPs participating in the DOE CCHP Tech Challenge.
---------------------------------------------------------------------------

    In response to AHRI's comment, DOE notes that the scope of the 
ENERGY STAR CVP only includes ENERGY STAR CCHPs, specifically 
performance at the 5 [deg]F test condition. In contrast, the CVP 
outlined in AHRI 210/240-202X Draft and AHRI 1600-202X Draft is 
applicable more broadly to all variable-capacity CAC/HPs. Because of 
the increased scope of the latter CVP, more heating test conditions are 
included, resulting in increased heating tests, both in number and 
duration. The CVP outlined in appendix I of AHRI 210/240-202X Draft and 
AHRI 1600-202X Draft also includes a 5 [deg]F test for all CHPs that 
report performance at the H4 conditions, and is functionally the same 
test as the ENERGY STAR CVP.
    In response to LG, DOE notes that although the ``Min/Mild'' CVP is 
a load-based method, it has a different method of inducing the 
conditioning load on the indoor psychrometric chamber as opposed to the 
CVP outlined in AHRI 210/240-202X Draft and AHRI 1600-202X Draft. As 
DOE detailed in the January 2023 RFI, the ``Min/Mild'' CVP uses the 
test chamber-induced load application scheme, where a fixed cooling or 
heating load is applied to the psychrometric chamber, and the unit 
under test responds to the test chamber-induced load to maintain the 
desired set point temperature. 88 FR 4091, 4094-4095. In contrast, the 
CVP in AHRI 210/240-202X Draft and AHRI 1600-202X Draft uses the 
virtual load approach, where the load is varied to simulate the 
building response if the capacity of the unit under test does not match 
the imposed load. Id. DOE notes that the CVP outlined in appendix I of 
AHRI 210/240-202X Draft and AHRI 1600-202X Draft represents industry 
consensus to ensure that fixed-speed settings of variable-speed systems 
would be achieved using native (unfixed) control. 89 FR 24206, 24222. 
Therefore, DOE considers that the CVP in appendix I of AHRI 210/240-
202X Draft and AHRI 1600-202X Draft is the most suitable option to 
support enforcement associated with testing conducted in accordance 
with appendices M1 and M2.
(2) Delaying CVP Compliance Due to Uncertain CVP Tolerances
    As noted in section III.E.1 of this document, DOE proposed in the 
April 2024 NOPR that systems determined to be variable-capacity 
compressor systems; variable-capacity certified, single-capacity 
systems; or variable-capacity certified, two-capacity systems after 
conducting the CVP, must meet tolerances of 6 percent and 10 percent on 
capacity and energy efficiency, respectively. 89 FR 24206, 24244.
    Lennox commented that the proposed tolerances appeared to be 
reasonable from Lennox's testing, but it noted that DOE should ensure 
that the proposed tolerances are not very stringent and expressed its 
openness to talk with DOE on the matter. (Lennox, No. 24 at p. 5) The 
Joint Advocates also supported the proposed tolerance values and 
requested that DOE continue evaluating appropriate values for the 
tolerances. (Joint Advocates, No. 30 at p. 1).
    AHRI, Carrier, Daikin, GE Appliances, JCI, LG, and Rheem had 
several issues with the aforementioned tolerances on capacity and 
energy efficiency for the CVP enforcement proposed by DOE, and they 
requested that DOE delay the compliance date CVP enforcement testing. 
(AHRI, No. 25 at p. 8; Carrier, No. 29 at p. 2; Daikin, No. 36 at pp. 
3-4; GE Appliances, No. 37 at p. 4; JCI, No. 35 at pp. 2-3; LG, No. 38 
at p. 1; Rheem, No. 34 at p. 5)
    AHRI commented that even though the tolerances proposed by DOE were 
discussed with all stakeholders during development of the AHRI 210/240 
and AHRI 1600 standards, AHRI is aiming to conduct CVP testing during 
2025, analyze the proposed tolerances, and provide the relevant 
information to DOE by spring 2026, which will determine if the proposed 
tolerances are supported by test data. (AHRI, No. 25 at p. 8) 
Therefore, AHRI requested that DOE defer the effective date of CVP 
enforcement provisions to July 2026 at the earliest. (Id. at p. 9)
    Carrier recommended that DOE delay the compliance date of the CVP 
enforcement to be 360 days after the publication of the final rule and 
revisit the proposed tolerances on capacity and efficiency once the 
industry has test data available to confirm appropriate tolerance 
values. (Carrier, No. 29 at p. 2) Carrier further commented that even 
though the tolerances proposed by DOE were discussed with stakeholders 
during the Unitary Small Equipment Standards Technical Committee (``USE 
STC'') negotiations, the consensus was

[[Page 1257]]

to not specify any tolerances at that time due to a lack of lab test 
data and uncertainty in the CVP. (Id.) Carrier expressed concern that 
the proposed tolerances would result in inappropriate characterization 
of system performance and may require manufacturers to retest and 
recertify products, thereby increasing the cost of testing. (Id.)
    Daikin commented that it does not have sufficient test data from 
Daikin's own test laboratories to agree or disagree with the tolerances 
proposed by DOE. (Daikin, No. 36 at pp. 3-4) Daikin requested that DOE 
be open to delay CVP enforcement dates and changes to the tolerances 
once stakeholders can provide test data to either validate or modify 
the current tolerances. (Id.)
    GE Appliances commented that it agrees with AHRI's recommendation 
on delaying CVP enforcement to no sooner than July 2026. (GE 
Appliances, No. 37 at p. 4) GE Appliances further commented that this 
will allow time for lab testing to validate DOE's proposed tolerances, 
and for building additional lab capacity for CVP testing, which takes 
longer than some existing CVP procedures, such as the ENERGY STAR CVP. 
(Id. at pp. 4-5) GE Appliances expressed concern that there are some 
items \62\ in the CVP in AHRI 210/240 that may require changes to the 
tolerances proposed by DOE. (Id.) GE Appliances pointed to a mismatch 
between the text and the equations in 10 CFR 429.134(k)(4)(iii)(B), 
stating that the language regarding capacity and efficiency tolerances 
provide for a two-sided tolerance, while the formulas only allow for 
one side of the range. (Id. at p. 5) GE Appliances recommended that the 
capacity equations should be modified to show a two-sided tolerance 
(ensuring consistency with the text), but since a one-sided tolerance 
seems appropriate for efficiency, the text in 429.134(k)(4)(iii)(D) 
should be updated to note that the equations are not ``within'' the 
specified tolerance and are one sided. (Id.)
---------------------------------------------------------------------------

    \62\ GE Appliances, in its example, pointed out that the target 
sensible load for the full-load and low-load tests were set at 97 
percent and 103 percent respectively, which may lead to unbalanced 
bilateral tolerance.
---------------------------------------------------------------------------

    JCI commented that since the CVP tests proposed in AHRI 210/240 are 
complex and time consuming, it is crucial for laboratories under the 
AHRI audit program to put in place tolerances that are achievable. 
(JCI, No. 35 at p. 3) JCI requested that DOE delay CVP enforcement 
testing until sufficient CVP test data has been collected by labs to 
establish such tolerances. (Id.)
    LG commented that since the CVP is a new and untried procedure, the 
capacity and efficiency tolerances proposed by DOE, of 6 percent and 10 
percent respectively, should be reevaluated before finalizing the CVP 
enforcement. (LG, No. 38 at p. 1) LG asserted that the proposed 
tolerances may not be sufficient to compare a certification test with 
the CVP test, noting that the certification tests utilize fixed 
compressor speed and airflow rate while the CVP tests modulate 
compressor speed and airflow rate to optimize thermal comfort and 
system performance. (Id.) Additionally, LG commented that even though 
the CVP would only be utilized during enforcement testing, 
manufacturers would need to verify CVP test values in order to 
internally assess the products, for which third-party testing may also 
be required to obtain reliable test data. (Id. at p. 3) LG asserted 
that while self-verification in the manufacturer's internal lab may be 
available, this option also requires additional testing time and cost. 
(Id.) Therefore, LG requested that DOE align the compliance date of the 
CVP enforcement with appendix M2's effective date, since manufacturers 
will have to do some retesting and recertification with the advent of 
appendix M2, and this would help reduce their overall test burden. 
(Id.)
    Similarly, Rheem questioned if there was adequate test data 
available to justify the tolerances on capacity and energy efficiency 
proposed by DOE for the full- and minimum-load intervals. (Rheem, No. 
34 at p. 5) Rheem requested delaying the compliance data of the CVP to 
July 2026 so that the CVP test data collected by AHRI in 2025 may be 
analyzed and help validate the proposed tolerances. (Id.) Rheem 
referred to a residential furnace fans final rule published by DOE in 
the Federal Register on July 3, 2014 (``July 2014 Furnace Fan Final 
Rule''), in which the fan energy rating (``FER'') metric's enforcement 
was delayed by DOE. (Id. at p. 6) Rheem commented that DOE should 
utilize the aforementioned flexibility in delaying enforcement 
provisions, in order to delay enforcement of the CVP. (Id.) Rheem noted 
that section I5.1.5 from appendix I of AHRI 210/240-2024 and AHRI 1600-
2024--which prescribes a maximum allowable variation in EER/COP equal 
to 5 percent--is redundant, given that all condition and operating 
tolerances have already been prescribed in section I5 and in the CVP 
enforcement provisions by DOE at 10 CFR 429.134(k). (Id. at p. 7)
    As noted by AHRI, the CVP tolerances on capacity and efficiency, 6 
percent and 10 percent, respectively, were discussed with the 
stakeholders during the development of the AHRI standards. During these 
discussions, DOE presented unit capacity, compressor speed, and 
efficiency data on 10 different variable-speed CHPs--five (5) ducted 
split CHPs and five (5) ductless mini-split CHPs. The CHP units were 
from seven (7) different manufacturers and had capacities ranging from 
1.5 tons to 3 tons. Regulatory cooling and heating tests were conducted 
on these units as per the existing appendix M1 procedure, and CVP tests 
were conducted using the test chamber-induced load application scheme, 
as explained in section III.I.2.b.(1) of this document. The SEER2 and 
HSPF2 metrics were evaluated for the units using both the regulatory 
test values and those obtained from the CVP. Table III-2 shows the 
comparison of the regulatory and CVP capacities and energy efficiency 
for each of the 10 units, for cooling full load, cooling low load, 
heating full load, and heating low load. The following can be observed, 
if 10% is the allowable tolerance for capacity and efficiency, when 
comparing the regulatory and CVP values: (1) unit 1 was out of 
tolerance on the cooling full load, and heating low load capacity and 
efficiency, (2) unit 3 was out of tolerance on the cooling low load 
capacity, and heating low load capacity and efficiency, (3) unit 6 was 
out of tolerance on the heating full load and heating low load capacity 
and efficiency, (4) unit 9 was out of tolerance on the cooling low load 
and heating low load efficiency, and (5) unit 10 was out of tolerance 
on the cooling low load and heating low load capacity and efficiency. 
For the aforementioned units, the SEER2 values were recalculated by use 
of the tested out of tolerance CVP load intervals and adjustment of the 
applicable load intervals without a CVP for full load or low load 
efficiencies and capacities, using the following equations:

[[Page 1258]]

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                                Table III-2--Regulatory and CVP Capacity and Energy Efficiency of 10 Variable Speed CHPs
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               Certification      CVP                                          %age            %age
              Unit No.                         Test           capacity (Btu/   capacity    Certification  CVP efficiency   difference in   difference in
                                                                    hr)        (Btu/hr)    efficiency *          *           capacity       efficiency
--------------------------------------------------------------------------------------------------------------------------------------------------------
1...................................  Cooling Full..........          22,515      25,343            13.2            11.6             -13              12
                                      Cooling Low...........           6,521       6,870            23.6            22.5               2               5
                                      Heating Full..........          18,853      18,659             2.0             2.0               1               0
                                      Heating Low...........          10,138      15,309             4.4             3.8              27              14
2...................................  Cooling Full..........          18,614      17,423            15.0            15.2               6              -2
                                      Cooling Low...........          11,444      12,325            17.6            15.8               5              10
                                      Heating Full..........          10,787      15,961             2.3             2.1             -48              11
                                      Heating Low...........           9,837      10,591             3.7             2.5               7              32
3...................................  Cooling Full..........          33,062      32,397            12.7            12.7               2               0
                                      Cooling Low...........          16,969      23,183            19.1            18.2              19               5
                                      Heating Full..........          19,038      19,120             2.0             2.1               0              -3
                                      Heating Low...........          16,373      20,290             4.9             4.3              21              13
4...................................  Cooling Full..........          34,439      33,290            13.0            12.7               3               3
                                      Cooling Low...........          13,196      13,660            24.2            24.5               1              -1
                                      Heating Full..........          18,707      25,224             2.1             1.9             -35              11
                                      Heating Low...........           9,880      10,081             4.1             4.1               1               1
5...................................  Cooling Full..........          22,655      21,477            13.5            13.8               5              -2
                                      Cooling Low...........           6,373       7,031            24.0            23.3               3               3
                                      Heating Full..........          19,415      18,423             2.1             2.0               5               3
                                      Heating Low...........          10,092      10,011             4.5             3.8               0              16
6...................................  Cooling Full..........          21,668      22,734            12.7            12.1              -5               5
                                      Cooling Low...........          11,124      11,018            20.8            18.8               0               9
                                      Heating Full..........          12,992      22,441             2.6             1.9             -73              26
                                      Heating Low...........           9,197      10,934             5.2             4.5              13              13
7...................................  Cooling Full..........          33,470      33,290            12.7            12.7               1               0
                                      Cooling Low...........          12,503      13,660            23.9            24.5               3              -2
                                      Heating Full..........          17,430      17,217             2.0             2.0               1              -1
                                      Heating Low...........           9,871       9,915             4.4             4.3               0               2
8...................................  Cooling Full..........          35,324      38,800            13.7            13.4             -10               3
                                      Cooling Low...........          20,254      20,824            19.9            19.1               2               4
                                      Heating Full..........          37,690      37,498             2.4             2.4               1               0
                                      Heating Low...........          20,128      19,479             4.5             4.4              -2               2
9...................................  Cooling Full..........          22,515      22,455            13.2            13.4               0              -2
                                      Cooling Low...........           6,521       6,602            23.6            18.3               0              22
                                      Heating Full..........          18,853      18,890             2.0             2.0               0               1
                                      Heating Low...........          10,138      10,199             4.4             3.9               0              12
10..................................  Cooling Full..........           15215       14969            14.1            13.3               2               6
                                      Cooling Low...........           4,752       5,497            30.3            27.3               5              10
                                      Heating Full..........          20,509      18,824             2.2             2.1               8               6
                                      Heating Low...........           3,644       4,998             6.1             5.1               7              17
--------------------------------------------------------------------------------------------------------------------------------------------------------
* EER2 for cooling tests (in Btu/hr/W), COP2 for heating tests.

    The recalculated SEER2 for units 1, 3, 6, 9 and 10, are shown in 
table III-3, indicating that the highest difference between the 
recalculated (or adjusted) SEER2 was no greater than 9.7%. Unit 6 was 
in tolerance for both the full and low load intervals and the reduction 
in SEER2 using the adjusted values was 6.3%. Therefore, it was 
concluded that a maximum energy efficiency tolerance of 10% would be 
appropriate for CVP enforcement of variable capacity compressor 
systems.

[[Page 1259]]



 Table III-3--Comparison of Recalculated SEER2 With the Certified SEER2 for Units That Were Out of Tolerance on
                                           Capacity and/or Efficiency
----------------------------------------------------------------------------------------------------------------
                                                                                               %age difference
                      Unit No.                         Certified SEER2     Adjusted SEER2   between adjusted and
                                                                                               certified SEER2
----------------------------------------------------------------------------------------------------------------
1...................................................              17.50              16.66                  -4.9
3...................................................              17.02              16.22                  -4.7
6...................................................              18.88              17.69                  -6.3
9...................................................              17.51              15.81                  -9.7
10..................................................              23.84              22.64                  -5.0
----------------------------------------------------------------------------------------------------------------

    For capacity, the tolerance of 6% was proposed in the April 2024 
NOPR, as a result of discussions with stakeholders during development 
of appendix I of the AHRI 210/240-202X Draft and AHRI 1600-202X Draft. 
89 FR 24206, 24243-24244. In appendix I of the AHRI 210/240-202X Draft 
and AHRI 1600-202X Draft, equations I2 and I3 show the calculation of 
the cooling virtual sensible load at outdoor conditions of 95 [deg]F 
and 67 [deg]F, respectively, and equations I9, I10, and I11 show the 
calculation of the heating virtual load at outdoor conditions of 5 
[deg]F, 17 [deg]F, and 47 [deg]F, respectively. Each of these equations 
provide a 3% factor on the cooling and heating full load and low load 
target virtual loads. Based on the data presented above in table III-2 
and the discussions with relevant stakeholders during the development 
of appendix I of the AHRI 210/240-202X Draft, DOE has determined 6% as 
an appropriate tolerance for capacity measurements during the CVP test.
    During development of the AHRI Standards, no counter data was 
presented by any of the stakeholders to suggest revising the tolerances 
of 6% on unit capacity, and 10% on unit efficiency, for CVP 
enforcement. DOE has also not received any CVP test data in response to 
the April 2024 NOPR to indicate that the proposed tolerances are not 
appropriate. Therefore, DOE is finalizing the aforementioned tolerances 
as part of the CVP enforcement provisions at 10 CFR 429.134(k).
    Regarding delaying the CVP enforcement date so that stakeholders 
have sufficient time to conduct CVP testing and for DOE to wait for 
AHRI's CVP testing in 2025 to help inform the proposed capacity and 
efficiency tolerances, DOE notes that the CVP is not required as part 
of testing, and a manufacturer is currently required to certify the 
compressor and indoor blower speed at settings that represent normal 
operation for any variable capacity system. Therefore, some form of 
validation to determine the settings for normal operation should 
already be in place to allow the manufacturers to properly certify 
these settings. The CVP outlined in appendix I of AHRI 210/240-202X 
Draft and AHRI 1600-202X Draft is intended to standardize such a 
procedure. Hence, even if manufacturers wanted to prepare to conduct 
the CVP on their products to prepare for potential enforcement by DOE, 
the test burden is limited.
    Regarding Rheem's comment on DOE delaying the enforcement of the 
FER metric for furnace fans, DOE clarifies that the FER metric was 
established as a regulatory metric, and is hence not comparable to the 
CVP procedure in appendix I of AHRI 210/240-202X Draft and AHRI 1600-
202X Draft, which DOE intends to utilize only for the purposes of 
assessment and enforcement testing of variable-capacity compressor 
systems. As discussed, the enforcement provisions explain what DOE may 
do in the case of enforcement testing for CAC/HPs and are not a 
requirement for manufacturer testing. As such, DOE does not see reason 
to delay the CVP enforcement provisions from their current effective 
date, i.e., 180 days after publication of this final rule in the 
Federal Register.
    DOE considers that the proposed tolerances on capacity and energy 
efficiency, of 6 percent and 10 percent, respectively, are currently 
the most appropriate values based on the variable-speed test data 
analyzed by DOE. At this time, no additional data is available nor has 
been provided by stakeholders and, therefore, DOE is finalizing its 
proposals on the tolerances and is not establishing a delayed effective 
date for the CVP. DOE welcomes any additional CVP test data as it 
becomes available.

[[Page 1260]]

[GRAPHIC] [TIFF OMITTED] TR07JA25.007

    In response to Rheem's comment (Rheem, No. 34 at p. 5) regarding 
the tolerances specified in section I5 in appendix I of AHRI 210/240-
202X Draft and AHRI 1600-202X Draft being redundant, DOE clarifies that 
this tolerance was incorporated in order to determine if the variable-
capacity compressor system under test met the stability requirements 
and subsequently determines the appropriate CVP test interval to be 
evaluated. Therefore, DOE disagrees with Rheem that this tolerance is 
redundant in the AHRI drafts.

[[Page 1261]]

[GRAPHIC] [TIFF OMITTED] TR07JA25.008

(3) Clarification on Enforcement Provisions
    Several commenters requested more clarity on the CVP enforcement 
provisions and made their own recommendations for some of the 
calculations and provisions proposed by DOE.
    The Joint Advocates pointed to DOE's proposal for evaluation of CVP 
results when tolerances on capacity and energy efficiency are not met, 
and the control used for conducting CVP does not provide means for 
overriding compressor and indoor blower speeds (10 CFR 
429.134(k)(4)(v)(B)) to adjust power measurements. (Joint Advocates, 
No. 30 at p. 2) In this case, the Joint Advocates commented that DOE 
proposed that power adjustment should be done by multiplication with 
the ratio of the efficiency measured during the CVP test interval 
divided by efficiency measured during the certification test (for the 
corresponding CVP interval). (Id.) The Joint Advocates noted that 
because of the 6-percent tolerance allowed for the full-load CVP 
interval-capacity measurements, the capacity ratio may not be equal to 
1, and hence it may not be appropriate to use the ratio of efficiencies 
(EER2 or COP2, as applicable). (Id.) The Joint Advocates suggested that 
DOE consider adjusting power by multiplying the ratio of powers, as 
follows:
[GRAPHIC] [TIFF OMITTED] TR07JA25.009

    Additionally, the Joint Advocates pointed to the provisions in 10 
CFR 429.134(k)(4)(v)(A) and (B)--where DOE proposed that for CVP tests 
for which capacity and efficiency tolerances are not met, the 
certification tests must be conducted by using the compressor speeds 
determined in the corresponding CVP test (or certification test results 
must be adjusted) and the certification tests will be used for 
calculating the unit's efficiency metrics. (Id. at p. 3) The Joint 
Advocates expressed concern that if the recalculated efficiency metric 
is compliant, but is lower than the value certified to DOE, this will 
result in a misleading efficiency rating and average energy cost 
printed on the FTC label. (Id.) The Joint Advocates pointed toward the 
rerate and recertify provision \63\ for VRF multi-split air 
conditioners and heat pumps (``VRF

[[Page 1262]]

multi-split systems''), which was specified by DOE in a final rule on 
October 20, 2022, suggesting that a similar provision should be adopted 
for CAC/HPs (``October 2022 VRF Final Rule''). 87 FR 63894.
---------------------------------------------------------------------------

    \63\ In the October 2022 VRF Final Rule, DOE specifies that if a 
manufacturer becomes aware that any of the certified operational 
settings for the critical parameters are determined to be invalid 
according to the results of a CVP, whether that CVP be performed by 
the manufacturer or another party, the manufacturer would be 
required to recertify the operational settings of those critical 
parameters for all affected basic models, as well as rerate and 
recertify the affected basic models.
---------------------------------------------------------------------------

    In response to the Joint Advocates' comment on adjustment of power 
of certification tests for which a corresponding CVP interval did not 
exist, DOE did an analysis on an example case for a variable-capacity 
CAC unit. DOE assumed that for a hypothetical variable-capacity 
compressor 3-ton CAC unit, with a certified EER2A,Full of 
12, the capacity at BFull condition was 40,000 Btu/hr, and 
the EER2B,Full was 15. It was assumed that after conducting 
the CVP on the unit, the value of the EER2 measured using the full-load 
CVP test dropped to 11.28, as shown in table III.4. DOE then evaluated 
the capacity and power at the BFull condition--the power was 
adjusted by using the energy efficiency ratios first, as proposed by 
DOE in the April 2022 CAC NOPR, and was separately adjusted by using 
the power ratios, as suggested by the Joint Advocates.
BILLING CODE 6450-01-P
[GRAPHIC] [TIFF OMITTED] TR07JA25.010

BILLING CODE 6450-01-C
    DOE observed that adjusting the power using the energy efficiency 
ratios resulted in the certification and CVP values for energy 
efficiency being out of tolerance, i.e., -11.6 percent, whereas 
adjusting the power using the power ratios resulted in this difference 
being -6 percent. Additionally, DOE revisited its analysis of the 
regulatory and CVP test data of the 10 variable-speed CHPs that was 
used to develop the 6-percent tolerance on capacity and 10-percent 
tolerance on efficiency, as explained in section III.I.2.b.(2) of this 
document. DOE observed that for one of the units, the power ratio 
adjusted EER2B,Low value was only 5.9 percent lower than the 
actual EER2 for the Blow CVP test, , but the efficiency 
ratio adjusted EER2B,Low was 26 percent higher than

[[Page 1263]]

the . DOE realizes that using the efficiency ratios to adjust power 
measurements may result in inflated energy efficiencies of the 
variable-capacity compressor units that DOE will run a CVP on. 
Therefore, DOE is adopting the proposed revision by the Joint Advocates 
and modifying the equations at 10 CFR 429.134(k)(4)(v)(B) that are used 
to adjust the power measurements for certification tests requiring 
adjustment with no CVP interval (any required certification test other 
than AFull, FLow, H1Low, 
H3Full, and H4Full), as follows:
    Cooling full power:
    [GRAPHIC] [TIFF OMITTED] TR07JA25.011
    
    Cooling minimum power:
    [GRAPHIC] [TIFF OMITTED] TR07JA25.012
    
    Heating minimum power:
    [GRAPHIC] [TIFF OMITTED] TR07JA25.013
    
    Regarding the Joint Advocates' recommendation to establish a rerate 
and recertify provision similar to the one in the October 2022 VRF 
Final Rule (see Sec.  429.43(b)(5)), DOE notes that if a variable-
capacity compressor system meets the minimum standards after the CVP 
assessment or enforcement, but the recalculated metric is lower than 
the value certified to DOE, DOE may choose to take enforcement action 
regarding invalid certification of the basic model. At this time, DOE 
is not adopting the rerate and recertify provision but may consider 
inclusion in a future certification rulemaking.
    In response to the CVP enforcement provisions, Rheem requested 
several clarifications and made its own recommendations, including some 
changes and corrections to the finalized standards, AHRI 210/240-2024 
and AHRI 1600-2024.
    Rheem requested clarification from DOE on the provisions in 10 CFR 
429.134(k)(4)(iii)(B) and (D). 89 FR 24206, 24259. (Rheem, No. 34 at p. 
6) Rheem noted that at 10 CFR 429.134(k)(4)(iii)(B) and (D), DOE 
proposed maximum allowable tolerances between the heating capacity and 
heating efficiency measured during the full-load interval of the CVP 
and the corresponding certification test. (Id.) Rheem commented that 
the proposed regulatory text in the section reads as if the full-load 
interval of the heating mode CVP must be conducted at both 17 [deg]F 
and 5 [deg]F, while section I4.2.1 of AHRI 210/240-2024 and AHRI 1600-
2024 does not require full-load interval of the heating CVP to be 
conducted at both 17 [deg]F and 5 [deg]F for all heat pumps. (Id.) 
Additionally, Rheem noted that in 10 CFR 429.134(k)(4)(i)(C), DOE 
proposed that the CVP will be allowed to be terminated without 
conducting the minimum load interval if, according to 10 CFR 429.134(k) 
(4)(ii)(B), a system is determined to be a variable-capacity certified, 
single-capacity system. 89 FR 24206, 24258. (Rheem, No. 34 at p. 6) 
Rheem commented that it interprets this provision to mean that in such 
a case, capacity, and energy efficiency tolerance at low-load 
intervals, as per 10 CFR 429.134(k)(4)(iii)(C) and (D), will not be 
necessary. (Id.) In 10 CFR 429.134(k)(v)(B), Rheem noted that DOE 
proposed to use the capacity slope factor (``CSF'') and power slope 
factor (``PSF'') for extrapolating an ``adjusted'' heating capacity and 
heating power consumption at H3 (17 [deg]F outdoor dry bulb 
temperature) test condition when the compressor is operating at low 
stage, using the system`s measured performance during the heating mode 
CVP's low-load interval. (Id.) 89 FR 24206, 24260-24261. Rheem 
commented that the values of CSF and PSF will be adopted from AHRI 210/
240-2024 or from section 3.6.4.1(b) of the current appendix M1, and it 
questioned their accuracy for low-speed compressor operation, since 
they were derived for compressor operation at full speed. (Rheem, No. 
34 at p. 6) In its comment, Rheem also questioned the extrapolation 
using these CSF and PSF values for minimum-speed-limiting heat pumps, 
as defined \64\ in AHRI 210/240-2024 and AHRI 1600-2024. (Id.) Finally, 
Rheem pointed to a typographical error in sections I4.3.1.4 of AHRI 
210/240-2024 and AHRI 1600-2024, and it made suggestions for correcting 
it.\65\ (Id.) Rheem commented that since no indoor entering wet bulb 
temperature is prescribed for any of the load and transition intervals 
of the heating CVP, corrections should be made in section I5.1 and 
section I5.1.3 of AHRI 210/240-2024 and AHRI 1600-2024 to reflect that 
any tolerances on indoor entering wet bulb temperatures should only be 
applicable to the cooling mode CVP tests. (Id. at p. 7)
---------------------------------------------------------------------------

    \64\ Minimum-speed-limiting variable-speed HPs are defined at 
section 3.2.32 of AHRI 210/240-202X Draft and 3.2.31 of AHRI 1600-
202X Draft as: A heat pump for which the minimum compressor speed 
(represented by revolutions per minute or motor power input 
frequency) is higher than its minimum value for operation in a 47 
[deg]F ambient temperature for any bin temperature tj for which the 
calculated heating load is less than the calculated intermediate-
speed capacity.
    \65\ Rheem suggested that either the phrase ``. . . where the 
range of capacity does not vary by more than 15 percent'' should be 
deleted fully, or the words ``. . . does not vary'' should be 
replaced with the word ``varies,'' since the AHRI USE STC's intent 
when developing this requirement was to encapsulate systems that 
cycle on/off, instead of modulating between compressor speeds/
stages.
---------------------------------------------------------------------------

    In response to Rheem`s comments, DOE clarifies that since the CVP 
for enforcement will be carried out as per appendix I of the AHRI 210/
240 and AHRI 1600 standards, the full-load interval of the heating mode 
CVP at 5 [deg]F will only be enforced for those CHPs that have reported 
regulatory

[[Page 1264]]

performance at the H4full test, while the CVP at 17 [deg]F 
will be carried out for all CHPs, including units for which performance 
at H4full conditions has not been reported. Additionally, 
DOE clarifies that for systems that are determined to be variable-
capacity certified, single-capacity systems, as per 10 CFR 429.134(k) 
(4)(ii)(B), there will be no need to conduct the minimum load interval, 
and therefore, Rheem's understanding that capacity and energy 
efficiency tolerance at low load intervals, as per 10 CFR 
429.134(k)(4)(iii)(C) and (D), will not be applicable, is correct. 
Regarding Rheem's comment on the use of CSF and PSF values from the 
AHRI standards, DOE notes that it has not received any test data from 
stakeholders that would indicate that the use of these slope factors is 
inaccurate at low compressor speed tests. In the absence of any test 
data, DOE is maintaining the CSF values of 0.0204/[deg]F for split 
systems and 0.0262/[deg]F for single-package units, and PSF value of 
0.00455/[deg]F, as per the April 2024 NOPR, to extrapolate an adjusted 
heating capacity and heating power consumption at H3 (17 [deg]F) test 
conditions when the compressor is operating at low stage, using tested 
system performance during the heating CVP's low load interval. The CSF 
and PSF values are used for extrapolation at the H3Low test 
condition capacity and heating power consumption only for Variable 
Capacity Certified, Two Capacity Systems, when the control device for 
conducting the CVP and certification tests does not meet the 
requirements of monitoring and adjustment of the compressor speed and 
indoor blower speed, as outlined in 10 CFR 429.134 (k)(4)(v)(A).
    In response to Rheem's comment on questioning this extrapolation 
for minimum-speed-limiting heat pumps, no evidence has been provided by 
Rheem to argue that the current CSF and PSF values may be inexact for 
the aforementioned extrapolation. However, DOE recognizes the concern 
raised by Rheem, and notes that systems determined to be Variable 
Capacity Certified, Two Capacity Systems, after conducting the CVP, 
will not be subject to extrapolation using the minimum speed limiting 
heat pump adjustments, as per equations 11.189 to 11.194 of AHRI 210/
240-2024 when tested in accordance with appendix M1, and per equations 
11.199 to 11.204 of AHRI 1600-2024, when tested in accordance with 
appendix M2. Additionally, DOE clarifies that there are no 
typographical errors in sections I4.3.1.4 of AHRI 210/240 and AHRI 
1600--the phrase ``. . . where the range of capacity does not vary by 
more than 15 percent'' is referring to the range of capacity the unit 
can modulate from its high-/on-capacity value and is therefore 
consistent with the intent of this section. Regarding Rheem's comment 
on tolerances on indoor entering wet bulb temperature and indoor 
leaving wet bulb temperature (in sections I5.1 and I5.1.3, 
respectively) in AHRI 210/240 and AHRI 1600, being applicable to 
cooling mode CVP tests only, DOE agrees, and it is making amendments at 
10 CFR 429.134(k)(4)(iii)(A) as follows (additions shown in italics):
    The data collected in the CVP per paragraph (k)(4)(i)(A) or 
paragraph (k)(4)(i)(B) of this section shall be evaluated for the 
duration of the individual CVP full or minimum load interval, excluding 
the preliminary 30 minutes of equilibrium data, to determine compliance 
with test condition tolerances and test operating tolerances listed in 
section I5.1 of appendix I of AHRI 210/240-2024 (incorporated by 
reference, see Sec.  429.4) (if testing in accordance with appendix 
M1); or of AHRI 1600-2024 (incorporated by reference, see Sec.  429.4) 
(if testing in accordance with appendix M2), with the exception that 
the indoor entering wet bulb deviation in section I5.1 and test 
operating tolerance in section I5.1.3 are applicable only for cooling 
mode CVP.
    JCI also requested clarity on various aspects of the CVP 
enforcement provisions. (JCI, No. 35 at pp. 2-3). In particular, JCI 
expressed concern about systems that utilize variable-capacity 
compressors rated as ``coil only'' systems and ``certified'' to DOE as 
variable-capacity systems, but which are rated and tested per two-speed 
test procedures.\66\ (Id.) JCI asserted that its concern stems from the 
broad definition of variable-capacity systems in AHRI 210/240-2024.\67\ 
(Id.) JCI commented that according to its interpretation, if such a 
system is certified to DOE as a multi- or variable-stage design but is 
tested to the coil-only two-stage test procedure, then the system is 
subject to CVP test requirements. (Id.)
---------------------------------------------------------------------------

    \66\ In the October 2022 CAC Final Rule, DOE defined ``variable-
speed communicating coil-only central air conditioner or heat pump'' 
and ``variable-speed non-communicating coil-only central air 
conditioner or heat pump.'' 87 FR 64550,64589. DOE`s understanding 
is that JCI is referring to non-communicating variable-speed coil-
only (``VSCO'') CAC/HPs in their comment, since the October 2022 CAC 
Final Rule established a two-stage test procedure for non-
communicating VSCO CAC/HPs. 87 FR 6450, 64591-64597. Such systems 
will only be tested using an on-off control signal and will not have 
any tests at intermediate speeds. Id.
    \67\ AHRI 210/240-2024 section 3.2.81 defines Variable Capacity 
System (Variable Capacity Air-conditioner or Variable Capacity Heat 
Pump): an air-conditioner or heat pump that has either a) a variable 
capacity compressor, or b) a digital compressor, and that controls 
the system by monitoring system operation and automatically 
modulating the compressor output, indoor airflow, and other system 
parameters as required in order to maintain the indoor room 
temperature.
---------------------------------------------------------------------------

    In a similar vein, JCI requested clarification on whether such 
systems, classified as OUWNMs (since they are sold in commerce without 
matching indoor units), would be subject to rating and testing per the 
CVP requirements. (JCI, No. 35 at pp. 2-3) Finally, JCI requested for 
clarification on whether DOE-certified, two-stage systems that have 
discrete fixed capacities and airflow rates, but are equipped with 
variable-capacity compressors, will be subject to the CVP enforcement 
or not. (Id. at p. 3)
    In response to JCI's comment regarding the variable-speed coil-only 
(``VSCO'') test provisions in the October 2022 CAC TP Final Rule, DOE 
clarifies that once the revised appendix M1 and the new appendix M2 are 
finalized, the VSCO test provisions for non-communicating and 
communicating systems in the current appendix M1 will be sunset. This 
is because these provisions are not part of the AHRI 210/240 and AHRI 
1600 standards, which are the basis of the revised appendix M1, and new 
appendix M2, respectively. Therefore, all VSCO systems will be 
certified and tested as variable-capacity compressor systems, and DOE 
may conduct the CVP on such units, to see if they comply with the 
variable-speed definition. JCI's question regarding OUWNMs is unclear--
however, DOE clarifies that the CVP is applicable to all variable-speed 
systems, and therefore, if such systems are certified as variable-speed 
systems, they will be subject to CVP enforcement. Finally, DOE 
clarifies that the CVP enforcement is applicable only to systems that 
are certified as variable-capacity compressor systems, as defined in 
section 3.2.80 of AHRI 210/240-2024 and AHRI 1600-2024. Therefore, any 
systems that are certified as two-capacity (or two-stage) systems, as 
defined in section 3.2.76 of AHRI 210/240-2024 and AHRI 1600-2024, will 
not be subject to CVP enforcement by DOE.
    GE Appliances supported the addition of a CVP for enforcement 
testing of variable-speed systems, but it commented that a number of 
lingering issues require resolution before DOE utilizes the CVP for 
enforcement testing.

[[Page 1265]]

(GE Appliances, No. 37 at p. 4) GE Appliances also commented that 
additional test data is required for validation of some provisions 
proposed by DOE in the April 2024 NOPR. (Id.) GE Appliances commented 
that the AHRI 210/240 standard specifies that the CVP tests should be 
done either with a proprietary control or with a simulated thermostat 
control, but it requested that DOE clarify when a control is considered 
proprietary, since multiple types of control systems are available, 
including those with hybrid control capability.\68\ (Id. at pp. 5-6)
---------------------------------------------------------------------------

    \68\ GE Appliances gave an example of hybrid control where an 
adaptor can be connected to a 24-V thermostat and variable-speed 
communicating equipment. For such control systems, the thermostat 
sends an on/off signal, and the adaptor then decides the set point 
temperature during unit operation.
---------------------------------------------------------------------------

    In response to GE Appliances, DOE clarifies that the differences 
between a proprietary control and simulated (generic) thermostat were 
discussed in detail with the stakeholders during the development of the 
AHRI 210/240 and AHRI 1600 standards. It is DOE's understanding and 
intent for implementation of the CVP that the ``control'' is the device 
that senses temperature in the conditioned space, has a user interface 
that allows setting of a desired space temperature (the ``set point''), 
and provides a signal or communication to the CAC or HP system that 
initiates system operation and/or steps or level of operation to reduce 
the gap between the temperature and the set point. Accordingly, as per 
the example scenario presented by GE Appliances in their comment, an 
adapter \69\ provided as part of the system or specified for 
installation that allows the basic model to connect with any generic 
(non-proprietary) thermostat is not the ``control.'' In the case in 
which such an adapter allows a generic thermostat to be installed in 
the conditioned space, the generic thermostat is the control, and the 
simulation of the generic thermostat (as described in section I3.1 of 
AHRI 210/240-2024 and AHRI 1600-2024) would be used. Only when the 
device measuring the space temperature and providing user input to 
adjust the set point is proprietary would installation of the 
proprietary device for the test be used. Any system having a ``hybrid'' 
control approach that could use either a generic or proprietary 
``control'' would be tested using the generic approach.
---------------------------------------------------------------------------

    \69\ DOE would like to clarify that if the adapter is an 
integral part of every unit shipped without a proprietary control 
that would otherwise not operate, the adapter would be connected to 
the simulated thermostat signal.
---------------------------------------------------------------------------

    LG also made several comments in response to the CVP enforcements 
proposed by DOE in the April 2024 NOPR. 89 FR 24206, 24258-24261. LG 
pointed out that as per the CVP, the indoor room`s set point is 
controlled according to the virtual load approach, in which the range 
of temperature difference between the thermostat set point and the 
indoor room condition during the proposed CVP test is 0-3 [deg]F. (LG, 
No. 38 at pp. 1-2) LG questioned whether the virtual load is 
appropriate for variable-capacity systems that do not operate at 
minimum speed when the indoor room temperature is not close to the 
thermostat set point. (Id.) LG further expressed concern that the term 
``certification'' test was not fully specified, as it could mean either 
(1) the tested value of the certification test, or (2) the value of the 
enforcement test conducted under the same conditions as the 
certification test. (Id. at p. 2) LG commented that if the 
``certification'' test was (1), it requests clarification if this would 
be a mean value of the two or more tested samples. (Id.) However, if it 
was (2), then LG requested that DOE provide more information on sample 
size and election.\70\ (Id.) Finally, LG recommended that due to 
existing deviations during testing, instead of comparing the CVP test 
values with the certification test values during enforcement, they 
should be compared to values provided by the manufacturer in the DOE 
database.\71\ (Id.)
---------------------------------------------------------------------------

    \70\ Currently, 10 CFR 429.16 (b)(3) describes the sampling plan 
for enforcement of CAC/HPs.
    \71\ DOE`s interpretation is that LG is referring to the 
Compliance Certification Database, available at 
www.regulations.doe.gov/ccms.
---------------------------------------------------------------------------

    In response to LG`s comment, DOE clarifies that the return air 
temperature equation in appendix I of AHRI 210/240-2024 is a function 
of the previous return air temperature target, RAT(t),time, the 
calculated virtual load (VLs for cooling mode CVP, and VL 
for heating mode CVP) at target outdoor ambient dry-bulb temperature 
Tj, measured unit capacity, and a thermal mass constant, C. 
The difference between the thermostat set-point and indoor room dry-
bulb temperature is dependent on the unit control and operation. The 
virtual load and return air temperature equations ensure the 
temperature difference between the thermostat set-point and indoor room 
dry-bulb temperature are within 1 [deg]F for systems that control the 
unit properly. The difference between the thermostat set-point and 
indoor room dry-bulb temperature could reach 3 [deg]F only if the unit 
could not achieve the virtual load target capacity at each test 
interval. Further, DOE clarifies that ``the corresponding certification 
test'' refers to an enforcement test conducted in accordance with 
appendix M1 or appendix M2, as applicable. The sample size of the 
selected units will be in accordance with provisions in 10 CFR 429.110. 
Finally, DOE clarifies that during the CVP enforcement, comparisons of 
the CVP full and minimum load intervals will be made to the 
certification test conducted just before the CVP tests.
    Carrier requested clarity from DOE on determining variable-speed 
unit operation when the intermediate tests do not show satisfactory 
variable-speed characteristics. (Carrier, No. 29 at p. 2) Specifically, 
Carrier commented that it was unclear on whether DOE`s proposal on a 
system`s cycling between stages is an accurate way of determining it is 
a single-capacity versus a two-capacity system, if the intermediate CVP 
requirement is not met. (Id.)
    In response to Carrier`s comment, DOE clarifies that 10 CFR 
429.134(k)(4)(C)(ii)(B) and (k)4)(C)(ii)(C) state that after conducting 
the CVP enforcement tests, the unit under test will be determined to be 
a variable-capacity certified, single-capacity system, or a variable-
capacity certified, two-capacity system, on the basis of the test 
results as per appendix I of AHRI 210/240 and AHRI 1600 (see section 
III.E.1 of this document for details). DOE reiterates that this 
determination, on whether a system is single capacity or two capacity, 
on the basis of its cycling between off and single-stage/capacity level 
and cycling between more than one stage/capacity level, respectively, 
represents industry consensus on this matter. This is because this 
determination was discussed and agreed upon with AHRI and all other 
stakeholders, during development of appendix I of the AHRI 210/240 and 
AHRI 1600 standards.

J. Test Procedure Costs and Impacts

    EPCA requires that test procedures proposed by DOE not be unduly 
burdensome to conduct. (42 U.S.C. 6293(b)(3)) As discussed, DOE is 
updating the current Federal test procedure for CAC/HPs at appendix M1 
consistent with the relevant industry consensus test procedure, AHRI 
210/240-2024. DOE is also establishing a new Federal test procedure at 
10 CFR part 430, subpart B, appendix M2, consistent with the new 
industry consensus test procedure, AHRI 1600-2024. Appendix M2 would 
not be required for use until the compliance date of amended standards 
for CAC/HPs. DOE is also amending its

[[Page 1266]]

representation and enforcement provisions for CAC/HPs.
1. Appendix M1
    In the April 2024 NOPR, DOE proposed to incorporate by reference 
AHRI 210/240-202X Draft and relevant industry standards referenced in 
AHRI 210/240-202X Draft at appendix M1. 89 FR 24206, 24244. DOE also 
proposed to amend certain provisions for representations and 
enforcement in 10 CFR part 429, consistent with the changes proposed to 
the test procedure. Id. DOE noted that the proposed revisions to 
appendix M1 would retain the current efficiency metrics (i.e., EER2, 
SEER2, and HSPF2). Id. DOE walked through the anticipated compliance 
costs associated with the proposed test procedure at appendix M1 and 
tentatively determined that proposed amendments would not result in an 
increase in testing cost relative to the current test procedure. Id. 
DOE also tentatively concluded that the proposed revisions to the test 
procedure in appendix M1 would not change efficiency ratings for CAC/
HPs, and therefore would not require retesting or redesign solely as a 
result of DOE's adoption of the proposed amendments to the DOE test 
procedure, if made final. Id. DOE requested comment on these tentative 
determinations under Issue 5 of the April 2024 NOPR. Id.
    In response, Lennox was supportive of DOE's tentative 
determinations, commenting that it believes the proposed appendix M1 
amendments in the April 2024 NOPR should result in a test procedure 
that is not unduly burdensome to conduct, consistent with EPCA 
statutory requirements. (Lennox, No. 24 at p. 6) While less supportive 
overall, Carrier commented that it agrees the proposed amendments to 
appendix M1 in the April 2024 NOPR would not result in any retesting or 
any increase in testing cost for a typical CAC/HP. (Carrier, No. 29 at 
p. 5) In addition, Carrier asserted that test costs and burden would 
increase, however, for certain products as a result of the proposed 
CVP- and CCHP-related provisions. (Id.)
    In addition to Carrier, Rheem and LG were also less supportive of 
DOE's tentative determinations, citing the additional test costs and 
burden associated with CVP testing. (Carrier, No. 29 at p. 5; LG, No. 
38 at p. 3; Rheem, No. 34 at p. 7) More specifically, Rheem commented 
that additional costs associated with the proposed test procedure will 
stem from modifications to psychrometric test cells in order to comply 
with the CVP. (Rheem, No. 34 at p. 7) LG commented that an extensive 
amount of time and associated costs are necessary to conduct CVP 
testing. (LG, No. 38 at p. 3) LG asserted that, in addition to 30 
minutes of stabilization time, it takes a minimum of 11.5 hours and a 
maximum of 20.5 hours for the cooling CVP test, and a minimum of 16.5 
hours and a maximum of 28.5 hours for the CCHP heating CVP test, 
resulting in third-party testing costs between 13,000 and 24,000 U.S. 
dollars. (Id.)
    In response to the Carrier, Rheem, and LG comments regarding 
additional test costs and burden associated with the CVP, DOE 
reiterates that the proposed CVP for variable-capacity compressor 
systems in appendix I of AHRI 210/240-2024 is not mandatory for 
manufacturers to perform. In the April 2024 NOPR, DOE also noted that, 
to the extent that a manufacturer has not already verified the 
appropriateness of the fixed performance during regulatory tests as 
compared to native control operation (i.e., the system may currently be 
improperly certified), a manufacturer may need to adjust fixed-speed 
overrides used in regulatory tests in accordance with the CVP and 
subsequently rerun the regulatory tests. 89 FR 24206, 24244-24245. 
However, having no strong evidence to the contrary, DOE noted it 
expects that current variable-capacity certifications are generally 
consistent with system performance. Id. As such, DOE concluded that any 
such cost to verify performance and potentially retest is negligible. 
Id.
    In response to Carrier's comment regarding additional test costs 
and burden associated with CCHP provisions (i.e., the required 
H42 test for products claimed as CCHPs), DOE reiterates that 
a manufacturer's claim of CCHP status for its product is optional. 89 
FR 24206, 24244-24245. DOE also reiterates that it anticipates products 
choosing to certify as CCHPs are most likely to be already testing at 
the 5 [deg]F condition, and hence have no added costs or test burden 
associated with them. Id.
    In this final rule, DOE is updating the incorporation by reference 
to AHRI 210/240-2024, the finalized version of AHRI 210/240-202X Draft. 
DOE is also referencing the relevant industry standards referenced in 
AHRI 210/240-2024 at appendix M1. As noted earlier, there are no 
substantial differences between AHRI 210/240-2024 and AHRI 210/240-202X 
Draft. As such, DOE's assessment of test procedure costs for appendix 
M1 are consistent with the April 2024 NOPR.
    DOE has determined that the amendments to appendix M1 and the 
representation and enforcement provisions would improve the 
representativeness, accuracy, and reproducibility of the test results 
and would not be unduly burdensome for manufacturers to conduct. DOE 
has determined that the amendments would not result in an increase in 
testing cost from the current test procedure. The revisions to the test 
procedure in appendix M1 for measuring EER2, SEER2, and HSPF2 per AHRI 
210/240-2024 would not increase third-party laboratory testing costs 
per unit relative to the current DOE test procedure. DOE estimates the 
current costs for physical testing, including off mode testing, to 
range from $10,800 to $19,800, depending on the configuration of the 
CAC/HP (single-stage, two-stage, variable-capacity). Further, DOE has 
concluded that the revisions to the test procedure in appendix M1 would 
not change efficiency ratings for CAC/HPs, and therefore would not 
require retesting or redesign solely as a result of DOE's adoption of 
the proposed amendments to the DOE test procedure.\72\
---------------------------------------------------------------------------

    \72\ Manufacturers are not required to perform laboratory 
testing on all basic models. In accordance with 10 CFR 429.16, CAC/
HP manufacturers may elect to use AEDMs. An AEDM is a computer 
modeling or mathematical tool that predicts the performance of non-
tested basic models. These computer modeling and mathematical tools, 
when properly developed, can provide a means to predict the energy 
usage or efficiency characteristics of a basic model of a given 
covered product or equipment and to reduce the burden and cost 
associated with testing.
---------------------------------------------------------------------------

2. Appendix M2
    In the April 2024 NOPR, DOE proposed to incorporate by reference 
AHRI 1600-202X Draft and relevant industry standards referenced in AHRI 
1600-202X Draft at appendix M2. 89 FR 24206, 24245. DOE also proposed 
to establish provisions for determining SCORE and SHORE, the new 
efficiency metrics applicable to appendix M2. Id. DOE walked through 
the anticipated compliance costs associated with the proposed test 
procedure at appendix M2 and tentatively determined that proposed 
amendments would not result in an increase in testing cost relative to 
the current test procedure. Id. DOE tentatively concluded that the 
proposed revisions to the test procedure in appendix M2 would change 
efficiency ratings for CAC/HPs--however, DOE noted testing and 
recertification based on appendix M2 would not be required until DOE 
adopts any amended CAC/HP standards in terms of the new metrics in a 
future energy conservation standards rulemaking. Id. DOE requested 
comment

[[Page 1267]]

on these tentative determinations under Issue 6 of the April 2024 NOPR. 
Id.
    In response, Lennox was supportive of DOE's tentative 
determinations, commenting that it believes the proposed appendix M2 in 
the April 2024 NOPR should result in a test procedure that is not 
unduly burdensome to conduct, consistent with EPCA statutory 
requirements. (Lennox, No. 24 at p. 6) Carrier agreed that the proposed 
appendix M2 in the April 2024 NOPR would not result in any increase in 
testing cost for a typical CAC/HP from the proposed appendix M1. 
(Carrier, No. 29 at p. 6) Rheem commented that it is not aware of 
available data to support the use of a different cost basis for 
appendix M2 testing. (Rheem, No. 34 at p. 7)
    In this final rule, DOE is updating the incorporation by reference 
to AHRI 1600-2024, the finalized version of AHRI 1600-202X Draft. DOE 
is also referencing the relevant industry standards referenced in AHRI 
210/240-2024 at appendix M1. As noted earlier, there are no substantial 
differences between AHRI 1600-2024 and AHRI 1600-202X Draft. As such, 
DOE's assessment of test procedure costs for appendix M2 are consistent 
with the April 2024 NOPR.
    DOE has determined that the amendments to appendix M2 and the 
representation and enforcement provisions would improve the 
representativeness, accuracy, and reproducibility of the test results 
and would not be unduly burdensome for manufacturers to conduct. DOE 
has determined that the amendments would not result in an increase in 
testing cost from the current test procedure. The revisions to the test 
procedure in appendix M2 for measuring EER2, SCORE, and SHORE per AHRI 
1600-2024 would not increase third-party laboratory testing costs per 
unit relative to the current DOE test procedure. DOE estimates the 
current costs for physical testing to range from $10,800 to $19,800, 
depending on the configuration of the CAC/HP (single-stage, two-stage, 
variable-capacity). DOE has concluded that the proposed revisions to 
the test procedure in appendix M2 would change efficiency ratings for 
CAC/HPs--however, testing and recertification based on appendix M2 
would not be required until DOE adopts any amended CAC/HP standards in 
terms of the new metrics in a future energy conservation standards 
rulemaking.

K. Effective, Compliance, and Other Required Use Dates

    The effective date for the adopted test procedure amendment will be 
30 days after publication of this final rule in the Federal Register. 
EPCA prescribes that all representations of energy efficiency and 
energy use, including those made on marketing materials and product 
labels must be made in accordance with an amended test procedure, 
beginning 180 days after publication of the final rule in the Federal 
Register. (42 U.S.C. 6293(c)(2)) However, CAC/HPs are not required to 
be tested according to the test procedure in appendix M2 (that relies 
on the SCORE and SHORE metrics) until the compliance date of amended 
energy conservation standards denominated in terms of SCORE and SHORE, 
should DOE adopt such standards.
    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.) To 
the extent the modified test procedure adopted in this final rule is 
required only for the evaluation and issuance of updated efficiency 
standards, compliance with the amended test procedure does not require 
use of such modified test procedure provisions until the compliance 
date of updated standards.
    Upon the compliance date of test procedure provisions in this final 
rule 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 are 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 
adopted in this document pertain to issues addressed by waiver granted 
to Samsung (88 FR 36558, Case No. 2022-009), as discussed in section 
III.E.4 of this final rule. To the extent that such interim waiver 
permits the petitioner to test according to an alternate test procedure 
to appendix M1, the interim waiver will terminate on the date the 
amendments to the appendix M1 test procedure take effect (i.e., 180 
days after publication of the test procedure final rule in the Federal 
Register).
    Notably, the amendments adopted in this final rule do not pertain 
to issues addressed by the interim waiver granted to Johnson Controls 
Inc. (``JCI'') (88 FR 72449, Case No. 2023-005) This interim waiver 
permits JCI to test certain basic models of CAC/HPs that use variable-
speed, oil-injected scroll compressors (``VSS systems'') with a 72-hour 
break-in period, in lieu of the 20-hour break-in limit prescribed in 
appendix M1. (Id.) The 72-hour break-in period permitted to the 
specific VSS systems listed in JCI's interim waiver is unique to the 
CAC/HP market, and DOE continues to assess whether there is a 
generalizable need for an extended break-in period for certain VSS 
systems beyond the specific basic models subject to the interim waiver 
granted to JCI. As such, DOE is not amending the test procedure to 
address the issues presented in the interim waiver granted to JCI at 
this time. To the extent the interim waiver permits JCI to test 
according to an alternate test procedure to appendix M1, the interim 
waiver will terminate on the date testing is required according to 
appendix M2, which will occur on the compliance date for updated 
efficiency standards. DOE notes that JCI may petition for another 
waiver at the time testing is required according to appendix M2.
    Additionally, as discussed in section III.E.7 of this final rule, 
DOE recognizes that stakeholders have requested clarification regarding 
the interaction of EPA's refrigerant regulations and DOE's 
certification and rating requirements for CAC/HPs. See table III-5 for 
a consolidated summary of the interaction of DOE's OUWNM certification 
and rating requirements under the EPA regulations timeline.

[[Page 1268]]



                     Table III-5--Summary of Certification and Rating Requirement Timelines
----------------------------------------------------------------------------------------------------------------
    Indoor or  outdoor unit                              Outdoor units with >700 GWP      Indoor units with >700
    manufactured or imported       Distributed as                refrigerant                  GWP refrigerant
----------------------------------------------------------------------------------------------------------------
Before 1/1/2025................  Matched System....  Per EPA, matched systems can be installed prior to January
                                                      1, 2026 as long as they were manufactured prior January 1,
                                                      2025.
                                                    ------------------------------------------------------------
                                 ..................  Must be certified/rated in           Must be certified/
                                                      combinations with indoor units as    rated in combinations
                                                      distributed in commerce before 1/1/  with outdoor units
                                                      2025 and the matched system must     distributed in
                                                      comply with applicable standard;     commerce before 1/1/
                                                      i.e., do not need to be certified/   2025 and the matched
                                                      rated as OUWNM.                      system must comply
                                                                                           with the applicable
                                                                                           standard.
                                                    ------------------------------------------------------------
                                 Indoor Unit or      Per EPA, indoor and outdoor units can also be installed as
                                  Outdoor Unit.       replacement units on or after January 1, 2025.
                                                    ------------------------------------------------------------
On or after 1/1/2025...........  Matched System....  Per EPA, matched systems can no longer be installed on or
                                                      after January 1, 2026.
                                                    ------------------------------------------------------------
                                 Indoor Unit or      Per EPA, indoor and outdoor units can be installed only as
                                  Outdoor Unit.       replacement units on or after January 1, 2026.
                                                    ------------------------------------------------------------
                                                     Must be certified/rated and as       Must be certified/
                                                      OUWNM and comply with the            rated in combinations
                                                      applicable standard.                 with outdoor units
                                                      Recertification/rerating required    distributed in
                                                      if previous ratings were matched     commerce before 1/1/
                                                      combinations. No new certification   2025 and the matched
                                                      of matched systems allowed.          system must comply
                                                                                           with the applicable
                                                                                           standard. No new
                                                                                           certification of
                                                                                           matched systems
                                                                                           allowed.
----------------------------------------------------------------------------------------------------------------

IV. Procedural Issues and Regulatory Review

A. Review Under Executive Orders 12866, 13563, and 14094

    Executive Order (``E.O.'') 12866, ``Regulatory Planning and 
Review,'' as supplemented and reaffirmed by E.O. 13563, ``Improving 
Regulation and Regulatory Review,'' 76 FR 3821 (Jan. 21, 2011) and 
amended by E.O. 14094, ``Modernizing Regulatory Review,'' 88 FR 21879 
(April 11, 2023), requires agencies, to the extent permitted by law, 
to: (1) propose or adopt a regulation only upon a reasoned 
determination that its benefits justify its costs (recognizing that 
some benefits and costs are difficult to quantify); (2) tailor 
regulations to impose the least burden on society, consistent with 
obtaining regulatory objectives, taking into account, among other 
things, and to the extent practicable, the costs of cumulative 
regulations; (3) select, in choosing among alternative regulatory 
approaches, those approaches that maximize net benefits (including 
potential economic, environmental, public health and safety, and other 
advantages; distributive impacts; and equity); (4) to the extent 
feasible, specify performance objectives, rather than specifying the 
behavior or manner of compliance that regulated entities must adopt; 
and (5) identify and assess available alternatives to direct 
regulation, including providing economic incentives to encourage the 
desired behavior, such as user fees or marketable permits, or providing 
information upon which choices can be made by the public. DOE 
emphasizes as well that E.O. 13563 requires agencies to use the best 
available techniques to quantify anticipated present and future 
benefits and costs as accurately as possible. In its guidance, the 
Office of Information and Regulatory Affairs (``OIRA'') in the Office 
of Management and Budget (``OMB'') has emphasized that such techniques 
may include identifying changing future compliance costs that might 
result from technological innovation or anticipated behavioral changes. 
For the reasons stated in this preamble, this final regulatory action 
is consistent with these principles.
    Section 6(a) of E.O. 12866 also requires agencies to submit 
``significant regulatory actions'' to OIRA for review. OIRA has 
determined that this final regulatory action does not constitute a 
``significant regulatory action'' under section 3(f) of E.O. 12866. 
Accordingly, this action was not submitted to OIRA for review under 
E.O. 12866.

B. Review Under the Regulatory Flexibility Act

    The Regulatory Flexibility Act (5 U.S.C. 601 et seq.) requires 
preparation of a final regulatory flexibility analysis (``FRFA'') for 
any final rule where the agency was first required by law to publish a 
proposed rule for public comment, unless the agency certifies that the 
rule, if promulgated, will not have a significant economic impact on a 
substantial number of small entities. As required by Executive Order 
13272, ``Proper Consideration of Small Entities in Agency Rulemaking,'' 
67 FR 53461 (August 16, 2002), DOE published procedures and policies on 
February 19, 2003 to ensure that the potential impacts of its rules on 
small entities are properly considered during the DOE rulemaking 
process. 68 FR 7990. DOE has made its procedures and policies available 
on the Office of the General Counsel's website: www.energy.gov/gc/office-general-counsel.
    DOE reviewed this final rule under the provisions of the Regulatory 
Flexibility Act and the procedures and policies published on February 
19, 2003. DOE has concluded that this rulemaking will not have a 
significant impact on a substantial number of small entities. 
Compliance with this test procedure is not required unless and until 
new energy conservation standards are established for covered CAC/HPs--
accordingly, there are no compliance costs stemming directly from this 
rulemaking.
    Still, although it is not required, DOE has undertaken a review of 
CAC/HP small business manufacturers and, in the following, is 
presenting the costs that those business may expect if testing on the 
basis of this test procedure were required in the future.

[[Page 1269]]

1. Estimated Number of Small Entities
    For the April 2024 NOPR, DOE conducted a focused inquiry into small 
business manufacturers of the products covered by this rulemaking. DOE 
used the SBA's small business size standards to determine whether any 
small entities would be subject to the requirements of the rule. The 
size standards are listed by North American Industry Classification 
System (``NAICS'') code as well as by industry description and are 
available at www.sba.gov/document/support-table-size-standards. 
Manufacturing CAC/HPs is classified under NAICS 333415, ``Air-
Conditioning and Warm Air Heating Equipment and Commercial and 
Industrial Refrigeration Equipment Manufacturing.'' 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 used available public 
information to identify potential small manufacturers. DOE accessed the 
Compliance Certification Database \73\ (``CCD''), the Modernized 
Appliance Efficiency Database System \74\ (``MAEDbS''), and the 
National Resources Canada database \75\ (``NRCan'') to create a list of 
companies that import or otherwise manufacture the products covered by 
this final rule. Once DOE created a list of potential manufacturers, 
DOE used market research tools to determine whether any met the SBA's 
definition of a small entity--based on the total number of employees 
for each company including parent, subsidiary, and sister entities--and 
gather annual revenue estimates.
---------------------------------------------------------------------------

    \73\ U.S. Department of Energy Compliance Certification 
Management System, available at www.regulations.doe.gov/ccms (last 
accessed July 30, 2023).
    \74\ California Energy Commission's Modernized Appliance 
Efficiency Database System, available at 
cacertappliances.energy.ca.gov/Login.aspx. (Last accessed Sept. 22, 
2023).
    \75\ Natural Resources Canada searchable product list, available 
at oee.nrcan.gc.ca/pml-lmp/ (last accessed Sept 19, 2023).
---------------------------------------------------------------------------

    Based on DOE's analysis, DOE identified 23 OEMs manufacturing CAC/
HPs covered by this test procedure. DOE screened out companies that do 
not meet the small entity definition and, additionally, screened out 
companies that are largely or entirely foreign owned and operated. Of 
the 23 OEMs identified OEMs, six were identified as domestic small 
businesses. DOE did not receive comments on the April 2024 NOPR in 
regard to its estimate of domestic small businesses.
2. Estimate of Small Business Testing Costs
    This final rule adopts updated industry test standards for CAC/HPs. 
DOE is updating the current Federal test procedure for CAC/HPs at 
appendix M1 consistent with the finalized version of the relevant 
industry consensus test procedure, AHRI 210/240-2024. DOE is also 
proposing a new Federal test procedure at 10 CFR part 430, subpart B, 
appendix M2, consistent with the finalized version of the industry 
consensus test procedure, AHRI 1600-2024. More specific amendments to 
the DOE test procedure are summarized in the following subsections.
(a) Cost and Compliance Associated With Appendix M1
    In appendix M1, DOE is incorporating by reference AHRI 210/240-2024 
for CAC/HPs and to amend certain provisions for representations and 
enforcement in 10 CFR part 429, consistent with the changes to the test 
procedure. 89 FR 24206, 24244. The revisions to appendix M1 would 
retain the previous test procedure's efficiency metrics--EER2, SEER2, 
and HSPF2. The testing requirements in appendix M1 are generally 
consistent with those in AHRI 210/240-2024, which in turn references 
ANSI/ASHRAE 37-2009, ANSI/ASHRAE 16-2016, and ANSI/ASHRAE 116-2010. 
This revision to the test procedure in appendix M1 for measuring EER2, 
SEER2, and HSPF2 would not increase third-party laboratory testing 
costs per unit relative to the current DOE test procedure. The Controls 
Verification Procedure (``CVP'') for variable-capacity compressor 
systems in appendix I of AHRI 210/240-2024 is not mandatory for 
manufacturers to perform, and DOE considers these developmental costs 
to be negligible and not burdensome to manufacturers. The 
H4full test (outdoor dry-bulb temperature of 5 [deg]F) will 
be mandatory, but DOE anticipates no added costs as units that will 
certify as CCHPs are likely currently testing at the 5 [deg]F 
condition. The determination of cut-in and cut-out temperatures in 
appendix J of the AHRI 210/240-2024 would be included in DOE's 
enforcement provisions and would not be mandatory for manufacturer 
testing, and thus manufacturers will not incur additional costs. 
Additionally, CAC/HPs equipped with mandatory circulation systems will 
have their cyclic degradation coefficients evaluated using respective 
cyclic tests, but DOE anticipates no added costs to manufacturers since 
cyclic tests are already often conducted on CAC/HPs (regardless of 
whether they are equipped with a mandatory constant circulation system) 
to improve the default cyclic degradation coefficients.
    DOE has concluded that the revisions to the test procedure in 
appendix M1 would not change efficiency ratings for CAC/HPs, and 
therefore would not require retesting as a result of DOE's adoption of 
this amendment to the test procedure.\76\ Further, the test procedure 
in appendix M1 would not increase third-party laboratory testing costs 
per unit; DOE estimates that the costs for physical testing prior to 
these amendments would range from $10,800 to $19,800, depending on the 
configuration of the CAC/HP (single-stage, two-stage, variable-
capacity). Therefore, DOE does not expect that the test procedure 
amendments in appendix M1 would result in manufacturers, including 
small manufacturers, incurring additional testing costs.
---------------------------------------------------------------------------

    \76\ Manufacturers are not required to perform laboratory 
testing on all basic models. In accordance with 10 CFR 429.16, CAC/
HP manufacturers may elect to use AEDMs. An AEDM is a computer 
modeling or mathematical tool that predicts the performance of non-
tested basic models. These computer modeling and mathematical tools, 
when properly developed, can provide a means to predict the energy 
usage or efficiency characteristics of a basic model of a given 
covered product or equipment and to reduce the burden and cost 
associated with testing.
---------------------------------------------------------------------------

(b) Cost and Compliance Associated With Appendix M2
    In appendix M2, DOE is establishing a new test procedure that 
references the industry test procedure, AHRI 1600-2024, for measuring 
new efficiency metrics, SCORE and SHORE. 89 FR 24204, 23245. Appendix 
M2 will not be effective until new standards are established for CAC/
HPs that rely on metrics present in appendix M2, should DOE adopt such 
standards. The testing requirements in appendix M2 are generally 
consistent with those in AHRI 1600-2024, which in turn references ANSI/
ASHRAE 37-2009, ANSI/ASHRAE 16-2016, and ASHRAE 116-2010. This revision 
to the test procedure in appendix M2 for measuring EER, SCORE, and 
SHORE is not expected to increase third-party laboratory testing costs 
per unit relative to the prior DOE test procedure. The standby and off-
mode power consumption of auxiliary components is determined using 
appendix G of AHRI 1600-2024 and does not differ substantially from the 
process to determine off-mode power from the current version of 
appendix M1, in section 3.13. The adoption of the new cooling and 
heating metric will not result in increased testing costs as compared 
to the previous test procedure. The other amendments--which include (a) 
building load lines and temperature bin hours for calculation of SCORE 
and SHORE, (b)

[[Page 1270]]

default fan power coefficients for coil-only systems, and (c) air flow 
limits to address inadequate dehumidification--also will not affect 
testing costs.
    The overall testing cost is not expected to increase with appendix 
M2. DOE estimates the costs of physical testing for the new metrics 
SCORE and SHORE to range from $10,800 to $19.800, depending on the 
configuration of the CAC/HP (single-stage, two-stage, variable-
capacity). Additionally, DOE allows the use of AEDMs. The use of an 
AEDM is expected to be less costly than physical testing of large 
numbers of CAC/HP models; DOE estimates the cost to develop an AEDM to 
be $19,383 per AEDM for a basic model, which includes the cost of 
physical testing done at a third-party laboratory to validate the 
AEDM.\77\ The development of the AEDM would reduce the need for 
physical testing on the part of manufacturers. Once the AEDM is 
developed, DOE estimates that it would take five minutes of an 
engineer's time to determine efficiency for each individual model 
within a basic model using the AEDM.
---------------------------------------------------------------------------

    \77\ DOE estimates that a mechanical engineer would take 60 
hours to create an AEDM. The fully burdened wage of a mechanical 
engineer is 68.05 based on an unburdened median wage of $47.84 and 
on wages representing 70.3 percent of labor costs. Average cost of 
third-party testing would be $14,400 given the previously described 
range of costs. See www.bls.gov/oes/current/oes172141.htm for the 
wage figure and www.bls.gov/news.release/archives/ecec_06182024.pdf 
for the wage percentage of labor costs figure.
---------------------------------------------------------------------------

    DOE understands all manufacturers currently certifying in the AHRI 
Directory (including small businesses) will be testing their models in 
accordance with AHRI 1600-2024, the industry test procedure DOE is 
referencing at appendix M2. As stated, testing and certification of the 
SCORE and SHORE metrics will not be required until the compliance date 
of any future energy conservation standards based on these metrics; 
however, DOE anticipates manufacturers will need to re-test their 
models to rate them in terms of the SCORE and SHORE metrics to comply 
with the AHRI certification program, and the re-rating will occur prior 
to a possible future energy conservation standards rulemaking. 
Accordingly, DOE has determined that the test procedure amendments 
would not add any additional testing burden to manufacturers--including 
the six domestic small manufacturers.
3. Certification Statement
    Based on the de minimis cost impacts, DOE certifies that this final 
rule does not have a ``significant economic impact on a substantial 
number of small entities,'' and determined that the preparation of a 
FRFA is not warranted. DOE will transmit a 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).

C. Review Under the Paperwork Reduction Act of 1995

    Manufacturers of CAC/HPs 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 CAC/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.
    DOE is not amending the certification or reporting requirements for 
CAC/HPs in this final rule. Instead, DOE may consider proposals to 
amend the certification requirements and reporting for CAC/HPs under a 
separate rulemaking regarding appliance and equipment certification. 
DOE will address changes to OMB Control Number 1910-1400 at that time, 
as necessary.
    Notwithstanding any other provision of the law, no person is 
required to respond to, nor shall any person be subject to a penalty 
for failure to comply with, a collection of information subject to the 
requirements of the PRA, unless that collection of information displays 
a currently valid OMB Control Number.

D. Review Under the National Environmental Policy Act of 1969

    In this final rule, DOE establishes test procedure amendments that 
it expects will be used to develop and implement future energy 
conservation standards for CAC/HPs. DOE has determined that this rule 
falls into a class of actions that are categorically excluded from 
review under the National Environmental Policy Act of 1969 (42 U.S.C. 
4321 et seq.) and DOE's implementing regulations at 10 CFR part 1021. 
Specifically, DOE has determined that adopting test procedures for 
measuring energy efficiency of consumer products and industrial 
equipment is consistent with activities identified in 10 CFR part 1021, 
appendix A to subpart D, A5 and A6. Accordingly, neither an 
environmental assessment nor an environmental impact statement is 
required.

E. Review Under Executive Order 13132

    Executive Order 13132, ``Federalism,'' 64 FR 43255 (August 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 examined this final 
rule and determined that it will 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 final 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 (February 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

[[Page 1271]]

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, 
this final 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 regulatory action resulting in a rule that may cause the 
expenditure by State, local, and Tribal governments, in the aggregate, 
or by the private sector of $100 million or more in any one year 
(adjusted annually for inflation), section 202 of UMRA requires a 
Federal agency to publish a written statement that estimates the 
resulting costs, benefits, and other effects on the national economy. 
(2 U.S.C. 1532(a)-(b)) The UMRA also requires a Federal agency to 
develop an effective process to permit timely input by elected officers 
of State, local, and Tribal governments on a proposed ``significant 
intergovernmental mandate,'' and requires an agency plan for giving 
notice and opportunity for timely input to potentially affected small 
governments before establishing any requirements that might 
significantly or uniquely affect small governments. On March 18, 1997, 
DOE published a statement of policy on its process for 
intergovernmental consultation under UMRA. 62 FR 12820; also available 
at www.energy.gov/gc/office-general-counsel. DOE examined this final 
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 proposed rule or policy that may affect 
family well-being. When developing a Family Policymaking Assessment, 
agencies must assess whether: (1) the action strengthens or erodes the 
stability or safety of the family and, particularly, the marital 
commitment; (2) the action strengthens or erodes the authority and 
rights of parents in the education, nurture, and supervision of their 
children; (3) the action helps the family perform its functions, or 
substitutes governmental activity for the function; (4) the action 
increases or decreases disposable income or poverty of families and 
children; (5) the proposed benefits of the action justify the financial 
impact on the family; (6) the action may be carried out by State or 
local government or by the family; and whether (7) the action 
establishes an implicit or explicit policy concerning the relationship 
between the behavior and personal responsibility of youth, and the 
norms of society. In evaluating the above factors, DOE has concluded 
that it is not necessary to prepare a Family Policymaking Assessment as 
none of the above factors are implicated. Further, this determination 
would not have any financial impact on families nor any impact on the 
autonomy or integrity of the family as an institution.

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 regulation will not 
result in any takings that might require compensation under the Fifth 
Amendment to the U.S. Constitution.

J. Review Under Treasury and General Government Appropriations Act, 
2001

    Section 515 of the Treasury and General Government Appropriations 
Act, 2001 (44 U.S.C. 3516 note) provides for agencies to review most 
disseminations of information to the public under guidelines 
established by each agency pursuant to general guidelines issued by 
OMB. OMB's guidelines were published at 67 FR 8452 (Feb. 22, 2002), and 
DOE's guidelines were published at 67 FR 62446 (Oct. 7, 2002). Pursuant 
to OMB Memorandum M-19-15, Improving Implementation of the Information 
Quality Act (April 24, 2019), DOE published updated guidelines which 
are available at www.energy.gov/sites/prod/files/2019/12/f70/DOE%20Final%20Updated%20IQA%20Guidelines%20Dec%202019.pdf. DOE has 
reviewed this final 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 significant energy action. A 
``significant energy action'' is defined as any action by an agency 
that promulgates 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 is likely to have a 
significant adverse effect on the supply, distribution, or use of 
energy; or (2) is designated by the Administrator of OIRA as a 
significant energy action. For any significant energy action, the 
agency must give a detailed statement of any adverse effects on energy 
supply, distribution, or use if the regulation is implemented, and of 
reasonable alternatives to the action and their expected benefits on 
energy supply, distribution, and use.
    This regulatory action 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

[[Page 1272]]

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 modifications to the test procedure for CAC/HPs adopted in this 
final rule incorporates testing methods contained in certain sections 
of the following commercial standards: AHRI 210/240-2024, AHRI 1600-
2024, ANSI/ASHRAE 37-2009 ANSI/ASHRAE 16-2016 and ASHRAE 116-2010. DOE 
has evaluated these standards and is unable to conclude whether they 
fully comply with the requirements of section 32(b) of the FEAA (i.e., 
whether they were developed in a manner that fully provides for public 
participation, comment, and review.) DOE has consulted with both the 
Attorney General and the Chairman of the FTC about the impact on 
competition of using the methods contained in these standards and has 
received no comments objecting to their use.

M. Congressional Notification

    As required by 5 U.S.C. 801, DOE will report to Congress on the 
promulgation of this rule before its effective date. The report will 
state that it has been determined that the rule is not a ``major rule'' 
as defined by 5 U.S.C. 804(2).

N. Description of Materials Incorporated by Reference

    In this final rule, DOE incorporates by reference the following 
test standards:
    AHRI 210/240-2024. This test standard is an update to AHRI 210/240-
2023 (2020), an industry-accepted test procedure for measuring the 
performance of Unitary Air-source Air-conditioners & Heat Pump 
Equipment. The revised appendix M1 will be consistent with provisions 
in AHRI 210/240-2024.
    AHRI 1600-2024. This test standard is a major update to AHRI 210/
240-2023 (2020), introducing new seasonal cooling and heating 
efficiency metrics, namely SCORE and SHORE. The new appendix M2 will be 
consistent with provisions in AHRI 210/240-2024.
    Copies of AHRI 210/240-2024 and AHRI 1600-2024 can be obtained from 
AHRI, 2311 Wilson Blvd., Suite 400, Arlington, VA 22201, (703) 524-
8800, or found online at www.ahrinet.org.
    ASHRAE 37-2009. This test standard is an industry-accepted test 
procedure that provides a method of test for many categories of air 
conditioning and heating equipment.
    ANSI/ASHRAE 16. This test standard is an industry-accepted test 
procedure that provides a method of test for room air conditioners, 
packaged terminal air conditioners, and packaged terminal heat pumps.
    ANSI/ASHRAE 116-2010. This test standard is an industry-accepted 
test procedure that provides a method of test for electrically driven, 
residential air-cooled air conditioners and heat pumps with cooling 
capacity of 65,000 Btu/hr. and less.
    Copies of ASHRAE 37-2009, ANSI/ASHRAE 16 and ANSI/ASHRAE 116-2010 
are available on ASHRAE's website at www.ashrae.org.
    The following standards were previously approved for incorporation 
by reference in the regulatory sections where they appear, and no 
changes are made: AHRI 210/240-2008, AHRI 1160, and ANSI 1230-2010.

V. Approval of the Office of the Secretary

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

List of Subjects

10 CFR Part 429

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

10 CFR Part 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 December 
18, 2024, by Jeffrey Marootian, 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 December 19, 2024.
Treena V. Garrett,
Federal Register Liaison Officer, U.S. Department of Energy.

    For the reasons stated in the preamble, DOE amends 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. Amend Sec.  429.4 by:
0
a. Revising paragraphs (a) and (c) introductory text;
0
b. Redesignating paragraphs (c)(2) through (7) as paragraphs (c)(3) 
through (8); and
0
c. Adding new paragraph (c)(2) and paragraph (c)(9).
    The revisions and additions read as follows:


Sec.  429.4  Materials incorporated by reference.

    (a) Certain material is incorporated by reference into this part 
with the approval of the Director of the Federal Register under 5 
U.S.C. 552(a) and 1 CFR part 51. To enforce any edition other than that 
specified in this section, the U.S. Department of Energy (DOE) must 
publish a document in the Federal Register and the material must be 
available to the public. All approved incorporation by reference (IBR) 
material is available for inspection at the Department of Energy (DOE) 
and at the National Archives and Records Administration (NARA). Contact 
DOE at: The U.S. Department of Energy, Office of Energy Efficiency and 
Renewable Energy, Building Technologies Office, EE-5B, 1000 
Independence Avenue SW, Washington, DC 20585-0121; (202) 586-9127; 
[email protected]; www.energy.gov/eere/buildings/appliance-and-equipment-standards-program. For information on the availability of 
this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations or email [email protected]. The material may be obtained 
from the sources in the following paragraphs of this section.
* * * * *

[[Page 1273]]

    (c) AHRI. Air-Conditioning, Heating, and Refrigeration Institute, 
2311 Wilson Blvd., Suite 400, Arlington, VA 22201, (703) 524-8800, or 
go to: www.ahrinet.org.
* * * * *
    (2) AHRI Standard 210/240-2024 (I-P), (``AHRI 210/240-2024''), 
Performance Rating of Unitary Air-conditioning and Air-source Heat Pump 
Equipment, copyright 2024; IBR approved for Sec.  429.134.
* * * * *
    (9) AHRI Standard 1600-2024 (I-P), (``AHRI 1600-2024''), 
Performance Rating of Unitary Air-conditioning and Air-source Heat Pump 
Equipment, copyright 2024; IBR approved for Sec.  429.134.
* * * * *

0
3. Amend Sec.  429.16 by revising paragraphs (a)(1) and (2), (a)(3)(i), 
(b)(2), (b)(3)(ii), (c)(1)(i)(B), (c)(1)(ii), (c)(3), (d)(2), and (f) 
to read as follows:


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

    (a) * * *
    (1) Required represented values. Determine the represented values 
(including as applicable, SEER2, EER2, HSPF2, PW,OFF, SCORE, 
SHORE, EER, cooling capacity, and heating capacity) for the individual 
models/combinations (or ``tested combinations'') specified in the 
following table.

                       Table 1 to Paragraph (a)(1)
------------------------------------------------------------------------
                                       Equipment           Required
            Category                  subcategory     represented values
------------------------------------------------------------------------
Single-Package Unit.............  Single-Package Air  Every individual
                                   Conditioner (AC)    model distributed
                                   (including space-   in commerce.
                                   constrained).
                                  Single-Package      Every individual
                                   Heat Pump (HP)      model distributed
                                   (including space-   in commerce.
                                   constrained).
Outdoor Unit and Indoor Unit      Single-Split-       Every individual
 (Distributed in Commerce by       System AC with      combination
 Outdoor Unit Manufacturer         Single-Stage or     distributed in
 (OUM)).                           Two-Stage           commerce. Each
                                   Compressor          model of outdoor
                                   (including Space-   unit must include
                                   Constrained and     a represented
                                   Small-Duct, High    value for at
                                   Velocity Systems    least one coil-
                                   (SDHV)).            only individual
                                                       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 Single-  distributed in
                                   Stage or Two-       commerce,
                                   Stage Compressor    including all
                                   (including Space-   coil-only and
                                   Constrained and     blower-coil
                                   SDHV).              combinations.
                                  Single-Split-       Every individual
                                   System HP           combination
                                   (including Space-   distributed in
                                   Constrained and     commerce.
                                   SDHV).
                                  Multi-Split, Multi- For each model of
                                   Circuit, or Multi-  outdoor unit, at
                                   Head Mini-Split     a minimum, a non-
                                   Split System--non-  ducted ``tested
                                   SDHV (including     combination.''
                                   Space-              For any model of
                                   Constrained).       outdoor unit also
                                                       sold with models
                                                       of ducted indoor
                                                       units, a ducted
                                                       ``tested
                                                       combination.''
                                                       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
                                                       (ii) of this
                                                       section,
                                                       respectively.
                                  Multi-Split, Multi- For each model of
                                   Circuit, or Multi-  outdoor unit, an
                                   Head Mini-Split     SDHV ``tested
                                   Split System--      combination.''
                                   SDHV.               Additional
                                                       representations
                                                       are allowed, as
                                                       described in
                                                       paragraph
                                                       (c)(3)(iii) of
                                                       this section.
Indoor Unit Only Distributed in   Single-Split-       Every individual
 Commerce by Independent Coil      System Air          combination
 Manufacturer (ICM).               Conditioner         distributed in
                                   (including Space-   commerce.
                                   Constrained and
                                   SDHV).
                                  Single-Split-
                                   System Heat Pump
                                   (including Space-
                                   Constrained and
                                   SDHV).

[[Page 1274]]

 
                                  Multi-Split, Multi- For a model of
                                   Circuit, or Multi-  indoor unit
                                   Head Mini-Split     within each basic
                                   Split System--      model, an SDHV
                                   SDHV.               ``tested
                                                       combination.''
                                                       Additional
                                                       representations
                                                       are allowed, as
                                                       described in
                                                       paragraph
                                                       (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.
------------------------------------------------------------------------

    (2) PW,OFF. Represented values of PW,OFF are 
only required when determining represented values in accordance with 10 
CFR part 430, subpart B, appendix M1. If individual models of single-
package systems or individual combinations (or ``tested combinations'') 
of split systems that are otherwise identical are offered with multiple 
options for off-mode-related components, determine the represented 
value for the individual model/combination with the crankcase heater 
and controls that are the most consumptive. A manufacturer may also 
determine represented values for individual models/combinations with 
less consumptive off-mode options; however, all such options must be 
identified with different model numbers for single-package systems or 
for outdoor units (in the case of split systems).
    (3) * * *
    (i) If a model of outdoor unit (used in a single-split, multi-
split, multi-circuit, multi-head mini-split, and/or outdoor unit with 
no match system) is distributed in commerce and approved for use with 
multiple refrigerants, a manufacturer must determine all represented 
values for that model using each refrigerant that can be used in an 
individual combination of the basic model (including outdoor units with 
no match or ``tested combinations''). This requirement may apply across 
the listed categories in the table 1 to paragraph (a)(1) of this 
section. A refrigerant is considered approved for use if it is listed 
on the nameplate of the outdoor unit.
* * * * *
    (b) * * *
    (2) Individual model/combination selection for testing. (i) Table 2 
to this paragraph (b)(2)(i) identifies the minimum testing requirements 
for each basic model that includes multiple individual models/
combinations; if a basic model spans multiple categories or 
subcategories listed in table 2, multiple testing requirements apply. 
For each basic model that includes only one individual model/
combination, test that individual model/combination.

                                         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
                                      Constrained).           seasonal.
                                     Single-Package HP       energy efficiency
                                      (including Space-       ratio 2 (SEER2).
                                      Constrained).          (when testing in
                                                              accordance with
                                                              appendix M1.
                                                             to subpart B of 10 CFR
                                                              part 430).
                                                             or seasonal cooling
                                                              and off-mode rating.
                                                             efficiency (SCORE)
                                                              (when testing.
                                                             in accordance with
                                                              appendix M2 to
                                                              subpart..
                                                             B of 10 CFR part 430).
Outdoor Unit and Indoor Unit         Single-Split-System AC  The model of outdoor    A model of coil-only indoor
 (Distributed in Commerce by OUM).    with Single-Stage or    unit.                   unit.
                                      Two-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    unit.
                                      Two-Stage Compressor
                                      (including Space-
                                      Constrained and SDHV).
                                     Single-Split System AC  The model of outdoor    A model of coil-only indoor
                                      or HP with Other Than   unit.                   unit.
                                      Single-Stage or Two-
                                      Stage Compressor
                                      having a coil-only
                                      individual
                                      combination
                                      (including Space-
                                      Constrained and SDHV).

[[Page 1275]]

 
                                     Single-Split System AC  The model of outdoor    A model of indoor unit.
                                      or 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-      unit.                   combination'' composed
                                      Head Mini-Split Split                           entirely of non-ducted
                                      System--non-SDHV                                indoor units. For any
                                      (including Space-                               models of outdoor units
                                      Constrained).                                   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).
                                                                                      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-      unit.                   composed entirely of SDHV
                                      Head Mini-Split Split                           indoor units.
                                      System--SDHV.
Indoor Unit Only (Distributed in     Single-Split-System     A model of indoor unit  The least efficient model
 Commerce by ICM).                    Air Conditioner                                 of outdoor unit with which
                                      (including Space-                               it will be paired where
                                      Constrained and SDHV).                          the least efficient model
                                                                                      of outdoor unit is the
                                                                                      model of outdoor unit in
                                                                                      the lowest SEER2
                                                                                      combination (when testing
                                                                                      under appendix M1 to
                                                                                      subpart B of 10 CFR part
                                                                                      430) or SCORE combination
                                                                                      (when testing under
                                                                                      appendix M2 to subpart B
                                                                                      of 10 CFR part 430) as
                                                                                      certified by the OUM. If
                                                                                      there are multiple models
                                                                                      of outdoor unit with the
                                                                                      same lowest SEER2 (when
                                                                                      testing under appendix M1
                                                                                      to subpart B of 10 CFR
                                                                                      part 430) or SCORE (when
                                                                                      testing under appendix M2
                                                                                      to subpart B of 10 CFR
                                                                                      part 430) represented
                                                                                      value, the ICM may select
                                                                                      one for testing purposes.
                                     Single-Split-System     Nothing, as long as an  ...........................
                                      Heat Pump (including    equivalent air
                                      Space-Constrained and   conditioner basic
                                      SDHV).                  model has been
                                                              tested. If an
                                                              equivalent air
                                                              conditioner basic
                                                              model has not been
                                                              tested, must test a
                                                              model of indoor unit.
                                     Multi-Split, Multi-     A model of indoor unit  A ``tested combination''
                                      Circuit, or Multi-                              composed entirely of SDHV
                                      Head Mini-Split Split                           indoor units, where the
                                      System--SDHV.                                   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
                                                                                      SEER2 combination (when
                                                                                      testing under appendix M1
                                                                                      to subpart B of 10 CFR
                                                                                      part 430) or SCORE
                                                                                      combination (when testing
                                                                                      under appendix M2 to
                                                                                      subpart B of 10 CFR part
                                                                                      430) as certified by the
                                                                                      OUM. If there are multiple
                                                                                      models of outdoor unit
                                                                                      with the same lowest SEER2
                                                                                      represented value (when
                                                                                      testing under appendix M1
                                                                                      to subpart B of 10 CFR
                                                                                      part 430) or SCORE
                                                                                      represented value (when
                                                                                      testing under appendix M2
                                                                                      to subpart B of 10 CFR
                                                                                      part 430), the ICM may
                                                                                      select one for testing
                                                                                      purposes.
Outdoor Unit with No Match.........  ......................  The model of outdoor    A model of coil-only indoor
                                                              unit.                   unit meeting the
                                                                                      requirements of section 4
                                                                                      of appendix M1 (when
                                                                                      testing under appendix M1
                                                                                      to subpart B of 10 CFR
                                                                                      part 430); or meeting the
                                                                                      requirements of section 3
                                                                                      of appendix M2 (when
                                                                                      testing under appendix M2
                                                                                      to subpart B of 10 CFR
                                                                                      part 430).
----------------------------------------------------------------------------------------------------------------

    (ii) When testing in accordance with appendix M1 to subpart B of 10 
CFR part 430, each individual model/combination (or ``tested 
combination'') identified in table 2 to paragraph (b)(2)(i) of this 
section is not required to be tested for PW,OFF. Instead, at 
a minimum, among individual models/combinations with similar off-mode 
construction (even spanning different models of outdoor units), a 
manufacturer must test at least one individual model/combination for 
PW,OFF.
    (iii) When testing in accordance with appendix M2 to subpart B of 
10 CFR part 430 and determining SCORE and SHORE, each individual model/
combination (or ``tested combination'') identified in table 2 to 
paragraph (b)(2)(i) of this section is not required to be tested for 
values of P1 (off-mode power in shoulder season) and 
P2 (off-mode power in heating Season). Instead, at a 
minimum, among individual models/combinations with similar off-mode 
construction (even spanning different models of outdoor units), a 
manufacturer must test at least one individual model/combination, for 
which P1 and P2 are the most consumptive.
    (3) * * *
    (ii) EER2, SEER2, HSPF2, SCORE, EER, and SHORE. Any represented 
value of the energy efficiency or other measure of energy consumption 
for which consumers would favor higher values shall be less than or 
equal to the lower of:
    (A) The mean of the sample, where:
    [GRAPHIC] [TIFF OMITTED] TR07JA25.014
    

and, x is the sample mean; n is the number of samples; and 
xi is the ith sample; or,


[[Page 1276]]


    (B) The lower 90 percent confidence limit (LCL) of the true mean 
divided by 0.95, where:
[GRAPHIC] [TIFF OMITTED] TR07JA25.015


and x is the sample mean; s is the sample standard deviation; n is the 
number of samples; and t0.90 is the Student's t-Distribution 
Value for a 90 percent one-tailed confidence interval with n-1 degrees 
of freedom (from appendix A to this subpart). Round represented values 
of EER2, SEER2, HSPF2, EER, SCORE and SHORE to the nearest 0.05.
* * * * *
    (c) * * *
    (1) * * *
    (i) * * *
    (B) The represented values of the measures of energy efficiency or 
energy consumption through the application of an AEDM in accordance 
with paragraph (d) of this section and Sec.  429.70. An AEDM may only 
be used to determine represented values for individual models or 
combinations in a basic model (or separate approved refrigerants within 
an individual combination) other than the individual model or 
combination(s) required for mandatory testing under paragraph (b)(2) of 
this section.
    (ii) When testing in accordance with appendix M1 to subpart B of 10 
CFR part 430, for every individual model/combination within a basic 
model tested pursuant to paragraph (b)(2) of this section, but for 
which PW,OFF testing was not conducted, the represented 
value of PW,OFF may be assigned through, either:
    (A) The testing result from an individual model/combination of 
similar off-mode construction; or
    (B) The application of an AEDM in accordance with paragraph (d) of 
this section and Sec.  429.70.
* * * * *
    (3) For multi-split systems, multi-circuit systems, and multi-head 
mini-split systems. The following applies:
    (i) When testing in accordance with appendix M1 to subpart B of 10 
CFR part 430, or appendix M2 to subpart B of 10 CFR part 430, for basic 
models that include additional varieties of ducted indoor units (i.e., 
conventional, low-static, or mid-static) other than the one for which 
representation is required in paragraph (a)(1) of this section, if a 
manufacturer chooses to make a representation, the manufacturer must 
conduct testing of a tested combination according to the requirements 
in paragraph (b)(3) of this section.
    (ii) When testing in accordance with appendix M1 to subpart B of 10 
CFR part 430, or appendix M2 to subpart B of 10 CFR part 430, for basic 
models that include mixed combinations of indoor units (any two kinds 
of non-ducted, low-static, mid-static, and conventional ducted indoor 
units), the represented value for the mixed combination is the mean of 
the represented values for the individual component combinations as 
determined in accordance with paragraph (b)(3) of this section.
    (iii) When testing in accordance with appendix M1 to subpart B of 
10 CFR part 430, or appendix M2 to subpart B of 10 CFR part 430, for 
basic models including mixed combinations of SDHV and another kind of 
indoor unit (any of non-ducted, low-static, mid-static, and 
conventional ducted), the represented value for the mixed SDHV/other 
combination is the mean of the represented values for the SDHV and 
other tested combination as determined in accordance with paragraph 
(b)(3) of this section.
    (iv) All other individual combinations of models of indoor units 
for the same model of outdoor unit for which the manufacturer chooses 
to make representations must be rated as separate basic models, and the 
provisions of paragraphs (b)(1) through (3) and (c)(3)(i) through (iii) 
of this section apply.
    (v) When testing in accordance with appendix M1 to subpart B of 10 
CFR part 430, and with respect to PW,OFF only, for every 
individual combination (or ``tested combination'') within a basic model 
tested pursuant to paragraph (b)(2) of this section, but for which 
PW,OFF testing was not conducted, the representative values 
of PW,OFF may be assigned through either:
    (A) The testing result from an individual model or combination of 
similar off-mode construction, or
    (B) Application of an AEDM in accordance with paragraph (d) of this 
section and Sec.  429.70.
    (d) * * *
    (2) Energy efficiency. Any represented value of the EER2, SEER2, 
HSPF2, EER, SCORE and SHORE, or other measure of energy efficiency of 
an individual model/combination for which consumers would favor higher 
values must be less than or equal to the output of the AEDM but no less 
than the standard.
* * * * *
    (f) Represented values for the Federal Trade Commission. Use the 
following represented value determinations to meet the requirements of 
the Federal Trade Commission.
    (1) Annual operating cost--cooling. Determine the represented value 
of estimated annual operating cost for cooling-only units or the 
cooling portion of the estimated annual operating cost for air-source 
heat pumps that provide both heating and cooling, as follows:
    (i) When using appendix M1 to subpart B of 10 CFR part 430, the 
product of:
    (A) The quotient of the represented value of cooling capacity, in 
Btu's per hour as determined in paragraph (b)(3)(iii) of this section, 
and multiplied by 0.93 for variable speed heat pumps only, divided by 
the represented value of SEER2, in Btu's per watt-hour, as determined 
in paragraph (b)(3)(ii) of this section.
    (B) The representative average use cycle for cooling of 1,000 hours 
per year;
    (C) A conversion factor of 0.001 kilowatt per watt; and
    (D) The representative average unit cost of electricity in dollars 
per kilowatt-hour as provided pursuant to section 323(b)(2) of the Act.
    (ii) When using appendix M2 to subpart B of 10 CFR part 430, the 
product of:
    (A) The quotient of the represented value of cooling capacity, in 
Btu's per hour as determined in paragraph (b)(3)(iii) of this section, 
and multiplied by 0.93 for variable speed heat pumps only, divided by 
the represented value of SCORE, in Btu's per watt-hour, as determined 
in paragraph (b)(3)(ii) of this section.
    (B) The representative average use cycle for cooling of 1,457 hours 
per year;
    (C) A conversion factor of 0.001 kilowatt per watt; and
    (D) The representative average unit cost of electricity in dollars 
per

[[Page 1277]]

kilowatt-hour as provided pursuant to section 323(b)(2) of the Act.
    (2) Annual operating cost--heating. Determine the represented value 
of estimated annual operating cost for air-source heat pumps that 
provide only heating or for the heating portion of the estimated annual 
operating cost for air-source heat pumps that provide both heating and 
cooling, as follows:
    (i) When using appendix M1 to subpart B of 10 CFR part 430, the 
product of:
    (A) The quotient of the represented value of cooling capacity (for 
air-source heat pumps that provide both cooling and heating) in Btu's 
per hour, as determined in paragraph (b)(3)(iii) of this section, or 
the represented value of heating capacity (for air-source heat pumps 
that provide only heating), as determined in paragraph (b)(3)(iii) of 
this section, divided by the represented value of HSPF2, in Btu's per 
watt-hour, calculated for Region IV, as determined in paragraph 
(b)(3)(ii) of this section;
    (B) The representative average use cycle for heating of 1,572 hours 
per year;
    (C) The adjustment factor of 1.15 (for heat pumps that are not 
variable speed) or 1.07 (for heat pumps that are variable speed), which 
serves to adjust the calculated design heating requirement and heating 
load hours to the actual load experienced by a heating system;
    (D) A conversion factor of 0.001 kilowatt per watt; and
    (E) The representative average unit cost of electricity in dollars 
per kilowatt-hour as provided pursuant to section 323(b)(2) of the Act;
    (ii) When using appendix M2 to subpart B of 10 CFR part 430, the 
product of:
    (A) The quotient of the represented value of cooling capacity (for 
air-source heat pumps that provide both cooling and heating) in Btu's 
per hour, as determined in paragraph (b)(3)(iii) of this section, or 
the represented value of heating capacity (for air-source heat pumps 
that provide only heating), as determined in paragraph (b)(3)(iii) of 
this section, divided by the represented value of SHORE, in Btu's per 
watt-hour, as determined in paragraph (b)(3)(ii) of this section;
    (B) The representative average use cycle for heating of 972 hours 
per year;
    (C) The adjustment factor of 1.15 (for heat pumps that are not 
variable speed) or 1.07 (for heat pumps that are variable speed), which 
serves to adjust the calculated design heating requirement and heating 
load hours to the actual load experienced by a heating system;
    (D) A conversion factor of 0.001 kilowatt per watt; and
    (E) The representative average unit cost of electricity in dollars 
per kilowatt-hour as provided pursuant to section 323(b)(2) of the Act;
    (3) Annual operating cost--total. Determine the represented value 
of estimated annual operating cost for air-source heat pumps that 
provide both heating and cooling by calculating the sum of the quantity 
determined in paragraph (f)(1) of this section added to the quantity 
determined in paragraph (f)(2) of this section.
    (4) Regional annual operating cost--cooling. Determine the 
represented value of estimated regional annual operating cost for 
cooling-only units or the cooling portion of the estimated regional 
annual operating cost for air-source heat pumps that provide both 
heating and cooling as follows:
    (i) When using appendix M1 to subpart B of 10 CFR part 430, the 
product of:
    (A) The quotient of the represented value of cooling capacity, in 
Btu's per hour as determined in paragraph (b)(3)(iii) of this section, 
and multiplied by 0.93 for variable speed heat pumps only, divided by 
the represented value of SEER2, in Btu's per watt-hour, as determined 
in paragraph (b)(3)(ii) of this section;
    (B) The estimated number of regional cooling load hours per year 
determined from the following table:

                    Table 4 to Paragraph (f)(4)(i)(B)
------------------------------------------------------------------------
                                                        Regional cooling
                   Climatic region                         load hours
------------------------------------------------------------------------
I....................................................              2,400
II...................................................              1,800
III..................................................              1,200
IV...................................................                800
V....................................................                400
VI...................................................                200
------------------------------------------------------------------------

    (C) A conversion factor of 0.001 kilowatts per watt; and
    (D) The representative average unit cost of electricity in dollars 
per kilowatt-hour as provided pursuant to section 323(b)(2) of the Act.
    (ii) When using appendix M2 to subpart B of part 430, regional 
annual operating cost for cooling-only units or the cooling portion of 
the estimated regional annual operating cost air-source heat pumps that 
provide both heating and cooling, does not apply.
    (5) Regional annual operating cost--heating. Determine the 
represented value of estimated regional annual operating cost for air-
source heat pumps that provide only heating or for the heating portion 
of the estimated regional annual operating cost for air-source heat 
pumps that provide both heating and cooling as follows:
    (i) When using appendix M1 to subpart B of 10 CFR part 430, the 
product of:
    (A) The estimated number of regional heating load hours per year 
determined from the following table:

                    Table 5 to Paragraph (f)(5)(i)(A)
------------------------------------------------------------------------
                                                        Regional cooling
                   Climatic region                         load hours
------------------------------------------------------------------------
I....................................................                493
II...................................................                857
III..................................................              1,247
IV...................................................              1,701
V....................................................              2,202
VI...................................................              1,842
------------------------------------------------------------------------

    (B) The quotient of the represented value of cooling capacity (for 
air-source heat pumps that provide both cooling and heating) in Btu's 
per hour, as determined in paragraph (b)(3)(iii)(C) of this section, or 
the represented value of heating capacity (for air-source heat pumps 
that provide only heating), as determined in paragraph (b)(3)(iii) of 
this section, divided by the represented value of HSPF2, in Btu's per 
watt-hour, calculated for the appropriate generalized climatic region 
of interest, and determined in paragraph (b)(3)(iii) of this section;
    (C) The adjustment factor of 1.15 (for heat pumps that are not 
variable speed) or 1.07 (for heat pumps that are variable speed), which 
serves to adjust the calculated design heating requirement and heating 
load hours to the actual load experienced by a heating system;
    (D) A conversion factor of 0.001 kilowatts per watt; and
    (E) The representative average unit cost of electricity in dollars 
per kilowatt-hour as provided pursuant to section 323(b)(2) of the Act.
    (ii) When using appendix M2 to subpart B of 10 CFR part 430, 
regional annual operating cost for air-source heat pumps that provide 
only heating or for the heating portion, does not apply.
    (6) Regional annual operating cost--total. For air-source heat 
pumps that provide both heating and cooling, the estimated regional 
annual operating cost is the sum of the quantity determined in 
paragraph (f)(4) of this section added to the quantity determined in 
paragraph (f)(5) of this section.
    (7) Annual operating cost--rounding. Round any represented values 
of estimated annual operating cost determined in paragraphs (f)(1) 
through (6) of this section to the nearest dollar per year.

[[Page 1278]]


0
4. Amend Sec.  429.70 by revising paragraphs (e)(1) and (e)(2)(i)(A) to 
read as follows:


Sec.  429.70  Alternative methods for determining energy efficiency and 
energy use.

* * * * *
    (e) * * *
    (1) Criteria an AEDM must satisfy. A manufacturer may not apply an 
AEDM to an individual model/combination to determine its represented 
values (EER2, SEER2, HSPF2, SCORE, EER, SHORE and/or PW,OFF) 
pursuant to this section unless authorized pursuant to Sec.  429.16(d) 
and:
    (i) The AEDM is derived from a mathematical model that estimates 
the energy efficiency or energy consumption characteristics of the 
individual model or combination (EER2, SEER2, HSPF2, EER, SCORE, SHORE 
and/or PW,OFF) as measured by the applicable DOE test 
procedure; and
    (ii) The manufacturer has validated the AEDM in accordance with 
paragraph (e)(2) of this section.
    (2) * * *
    (i) * * *
    (A) Minimum testing. The manufacturer must test each basic model as 
required under Sec.  429.16(b)(2).
* * * * *

0
5. Amend Sec.  429.134 by revising paragraph (k) to read as follows:


Sec.  429.134  Product-specific enforcement provisions.

* * * * *
    (k) Central air conditioners and heat pumps. Before July 7, 2025, 
the provisions in this section of this title as it appeared in the 10 
CFR parts 200-499 edition revised as of January 1, 2023, are 
applicable. On and after July 7, 2025, the following provisions apply.
    (1) Verification of cooling capacity. The cooling capacity of each 
tested unit of the individual model (for single-package systems) or 
individual combination (for split systems) will be measured pursuant to 
the test requirements of Sec.  430.23(m) of this chapter. The mean of 
the measurement(s) (either the measured cooling capacity for a single 
unit sample or the average of the measured cooling capacities for a 
multiple unit sample) will be used to determine the applicable 
standards for purposes of compliance.
    (2) Verification of CD value. (i) For central air 
conditioners and heat pumps other than models of outdoor units with no 
match, if manufacturers certify that they did not conduct the optional 
tests to determine the CD\c\ and/or CD\h\ value 
for an individual model (for single-package systems) or individual 
combination (for split systems), as applicable, for each unit tested, 
the default CD\c\ and/or CD\h\ value will be used 
as the basis for the calculation of SEER2 or HSPF2 when testing in 
accordance with appendix M1 to subpart B of 10 CFR part 430, or SCORE 
or SHORE when testing in accordance with appendix M2 to subpart B of 10 
CFR part 430. If manufacturers certify that they conducted the optional 
tests to determine the CD\c\ and/or CD\h\ value 
for an individual model (for single-package systems) or individual 
combination (for split systems), as applicable, the following 
provisions apply.
    (A) If testing in accordance with appendix M1 to subpart B of 10 
CFR part 430, the CD\c\ and/or CD\h\ value will 
be measured for each unit tested pursuant to appendix M1 to subpart B 
of 10 CFR part 430 and the result for each unit tested (either the 
tested value or the default value, as selected according to the 
criteria for the cyclic test in section E17 of AHRI 210/240-2024 
(incorporated by reference, see Sec.  429.4)) will be used as the basis 
for calculation of SEER2 or HSPF2.
    (B) If testing in accordance with appendix M2 to subpart B of 10 
CFR part 430, the CD\c\ and/or CD\h\ value will 
be measured for each unit tested pursuant to appendix M2 to subpart B 
of 10 CFR part 430 and the result for each unit tested (either the 
tested value or the default value, as selected according to the 
criteria for the cyclic test in section E17 of AHRI 1600-2024 
(incorporated by reference, see Sec.  429.4)) will be used as the basis 
for calculation of SCORE or SHORE.
    (ii) For models of outdoor units with no match, DOE will use the 
default CD\c\ and/or CD\h\ pursuant to appendix 
M1 to subpart B of 10 CFR part 430 or appendix M2 to subpart B of 10 
CFR part 430, as applicable.
    (3) Verification of cut-out and cut-in temperatures for central 
heat pumps. (i) When testing in accordance with appendix M1 to subpart 
B of 10 CFR part 430, the cut-out and cut-in temperatures may be 
verified using the method in appendix J of AHRI 210/240-2024 
(incorporated by reference, see Sec.  429.4). If this method is 
conducted, the tested TOFF,T and TON,T values 
determined in the test shall be used as the cut-out and cut-in 
temperatures, respectively, to calculate HSPF2.
    (ii) When testing in accordance with appendix M2 to subpart B of 10 
CFR part 430, the cut-out and cut-in temperatures may be verified using 
the method in appendix J of AHRI 1600-2024 (incorporated by reference, 
see Sec.  429.4). If this method is conducted, the tested 
TOFF,T and TON,T values determined in the test 
shall be used as the cut-out and cut-in temperatures, respectively, to 
calculate SHORE.
    (4) Verification of Variable Capacity Operation and of Fixed 
Settings for the Compressor and the Indoor Fan when Testing Variable 
Capacity Compressor Systems--(i) Conducting the controls verification 
procedure (CVP). A CVP may be performed for any model certified as a 
variable capacity compressor system for the purposes of assessment or 
enforcement testing conducted according to appendix M1 to subpart B of 
10 CFR part 430 or appendix M2 to subpart B of 10 CFR part 430 (i.e., 
the certification tests), as applicable. For a heat pump, either a 
cooling mode CVP, a heating mode CVP, or both may be conducted, as 
elected by DOE. If a CVP is not conducted, the override instructions 
for the compressor and indoor fan, as specified by the manufacturer, 
will be used to conduct the tests per appendix M1 to subpart B of 10 
CFR part 430 or, appendix M2 to subpart B of 10 CFR part 430, as 
applicable.
    (A) When testing in accordance with appendix M1 to subpart B of 10 
CFR part 430. The CVP will be conducted per appendix I of AHRI 210/240-
2024 (incorporated by reference, see Sec.  429.4).
    (B) When testing in accordance with appendix M2 to subpart B of 10 
CFR part 430. The CVP will be conducted per appendix I of AHRI 1600-
2024 (incorporated by reference, see Sec.  429.4).
    (C) Variable capacity certified, single capacity systems. For 
systems determined to be variable capacity certified, single capacity 
systems as described in paragraph (k)(4)(ii)(B) of this section, the 
CVP cooling and heating minimum intervals may be omitted.
    (ii) Variable capacity determination. (A) If the unit tested does 
meet the definition of a variable capacity compressor system based on 
performance of the CVP per paragraph (k)(4)(i)(A) or paragraph 
(k)(4)(i)(B) of this section, the efficiency metrics (SEER2, HSPF2, 
EER2, SCORE, SHORE, EER as applicable) shall be determined using the 
certification test applicable to variable capacity compressor systems.
    (B) If the unit tested does not meet the definition of a variable 
capacity compressor system based on performance of the CVP per 
paragraph (k)(4)(i)(A) or (B) of this section, and the tested unit is 
instead determined to be a variable capacity certified, single capacity 
system, the efficiency metrics (SEER2, HSPF2, EER2, SCORE, SHORE, EER 
as applicable) shall be determined using the certification test 
applicable to

[[Page 1279]]

variable capacity certified, single capacity systems.
    (C) If the unit tested does not meet the definition of a variable 
capacity compressor system based on performance of the CVP per 
paragraph (k)(4)(i)(A) or (B) of this section, and the tested unit is 
instead determined to be a variable capacity certified, two capacity 
system, the efficiency metrics (SEER2, HSPF2, EER2, SCORE, SHORE, EER 
as applicable) shall be determined using the certification test 
applicable to variable capacity certified, two capacity systems.
    (D) If, for a heat pump, a CVP is conducted for just one of the 
operating modes (heating or cooling), the system classifications for 
both modes will be based on the results of the one CVP conducted.
    (iii) CVP tolerance evaluation for full and minimum load intervals. 
(A) The data collected in the CVP per paragraph (k)(4)(i)(A) or (B) of 
this section shall be evaluated for the duration of the individual CVP 
full or minimum load interval excluding the preliminary 30 minutes of 
equilibrium data, to determine compliance with test condition 
tolerances and test operating tolerances listed in section I5.1 of 
appendix I of AHRI 210/240-2024 (if testing in accordance with appendix 
M1 to subpart B of 10 CFR part 430; (incorporated by reference, see 
Sec.  429.4)) or of AHRI 1600-2024 (if testing in accordance with 
appendix M2 to subpart B of 10 CFR part 430; (incorporated by 
reference, see Sec.  429.4)), with the exception that indoor entering 
wet bulb deviation in I5.1 and test operating tolerance in I5.1.3 is 
applicable only for cooling mode CVP.
    (1) If the specified tolerances are met under system operation for 
60 minutes, the average capacity and average power measured over this 
60-minute test interval shall be recorded.
    (2) If the four-hour time limit is reached by the system without 
maintaining the tolerances for a 60-minute period, but two successive 
test period sub-intervals are identified, each a minimum of 30 minutes, 
and comprised of a whole number of compressor cycles (either compressor 
on-off cycles or speed/capacity cycles) or in which minimal 
fluctuations of the compressor speed/capacity level are observed, where 
both the time averaged integrated capacity and time averaged integrated 
power of the two successive test period sub-intervals are observed to 
be within two percent of each other, a single capacity average and a 
single power average shall be recorded, both averaged over compressor-
on periods of the two successive test period sub-intervals. These 
average capacity and power values shall be considered the capacity and 
power values recorded for the test interval.
    (3) If the four-hour time limit is reached by the system without 
complying with either paragraph (k)(4)(iii)(A)(1) or (2) of this 
section, the time averaged integrated capacity and time averaged 
integrated power shall be recorded for only the compressor-on periods 
over the final 120 minutes of the test interval.
    (B) Determine whether the measured capacity for each full load 
interval, as evaluated per the CVP conducted in paragraph (k)(4)(i)(A) 
or (B) of this section, is no more than 6% less than the corresponding 
certification test capacity, as follows:
[GRAPHIC] [TIFF OMITTED] TR07JA25.016

Where:

qA,Full = Certification test capacity at AFull condition,
qCVP,A,Full = CVP test capacity at AFull condition,
qH3,Full = Certification test capacity at H3Full 
condition,
qCVP,H3,Full = CVP test capacity at H3Full condition,
qH4,Full = Certification test capacity at H4Full 
condition,
qCVP,H4,Full= CVP test capacity at H4Full condition,

    (C) Determine whether the measured capacity for each minimum load 
interval, as evaluated per the CVP conducted in paragraph (k)(4)(i)(A) 
or (B) of this section, is no more than 6% less than the corresponding 
certification test capacity, as follows:
[GRAPHIC] [TIFF OMITTED] TR07JA25.017

Where:

qCVP,F,Low= CVP test capacity at FLow condition,
qF,Low = Certification test capacity at FLow condition,
qCVP,H1,Low = CVP test capacity at H1Low condition,
qH1,Low= Certification test capacity at H1Low condition,

    (D) Determine whether the measured efficiency for the full and 
minimum load interval, as evaluated per the CVP conducted in paragraph 
(k)(4)(i)(A) or (B) of this section, is no more than 10% less than the 
corresponding certification test efficiency, as follows:

[[Page 1280]]

[GRAPHIC] [TIFF OMITTED] TR07JA25.018

[GRAPHIC] [TIFF OMITTED] TR07JA25.019

    (E) Cooling and heating efficiency requirements are shown using 
EER2 and COP2 to align with testing in accordance with appendix M1 to 
subpart B of 10 CFR part 430. When testing in accordance with appendix 
M2 to subpart B of 10 CFR part 430, replace EER2 with EER, and COP2 
with COP.
    (iv) Evaluation of results when CVP tolerances are met. If the 
tolerances for capacity and efficiency are met by the applicable full 
and minimum load intervals as per paragraphs (k)(4)(iii)(B) through (D) 
of this section, the certified override instructions for the compressor 
and indoor fan, as specified by the manufacturer, shall be deemed 
valid, and the efficiency metrics (SEER2, HSPF2, EER2, SCORE, SHORE, 
EER as applicable), shall be determined based on these certification 
tests with no adjustments determined based on the CVP results.
    (v) Evaluation of results when CVP tolerances are not met. If the 
tolerances for capacity and efficiency are not met by the applicable 
full and minimum load intervals as per paragraphs (k)(4)(iii)(B) 
through (D) of this section, the unit shall be tested per instructions 
in paragraphs (k)(4)(v)(A) through (C) of this section, as applicable. 
The instructions in paragraphs (k)(4)(v)(A) through (C) shall be 
followed, as applicable, only for the certification tests corresponding 
to the out of tolerance compressor speed interval based on the 
evaluations of paragraphs (k)(4)(iii)(B) through (D). For all 
compressor speed intervals for which the capacity and EER2/COP2/EER/COP 
are in tolerance as per paragraphs (k)(4)(iii)(B) through (D), the 
corresponding certification tests shall be used without adjustments.
    (A) The instructions of this paragraph shall be applied to systems 
for which the same control device used as per the CVP conducted in 
paragraph (k)(4)(i)(A) or (B) of this section is used as the means for 
overriding the controls, and both of the following are supported by the 
control device: monitoring of the compressor and indoor blower speed 
during native-control operation without otherwise impacting the control 
of the system; and monitoring and adjustment of the compressor and 
indoor blower speed during certification tests, where monitoring and 
adjustment means the control device has the ability to display and make 
discrete adjustments, as required, to the compressor and indoor blower 
speeds without additional hardware or non-publicly available software.
    (1) The compressor and indoor blower speed shall be monitored 
during the CVP conducted in paragraph (k)(4)(i)(A) or (B) of this 
section. The average compressor and indoor blower speeds and indoor air 
volume rate shall be evaluated for the same time period(s) used as 
described in paragraph (k)(4)(iii)(A) of this section to determine 
average capacity and power for the CVP test. The compressor speed for 
the certification test shall be set at this average value observed 
during the corresponding CVP test interval. The indoor blower speed 
shall be set as described in section 6.1.5 of AHRI 210/240-2024 (if 
testing in accordance with appendix M1 to subpart B of 10 CFR part 430; 
(incorporated by reference, see Sec.  429.4)) or of AHRI 1600-2024 (if 
testing in accordance with appendix M2 to subpart B of 10 CFR part 430; 
(incorporated by reference, see Sec.  429.4)), except the ``specified 
airflow'' shall be set as the average value observed during the 
corresponding CVP test interval. The same adjusted compressor speed 
shall be used for the other certification tests that require the same 
speed, as applicable, as detailed in table 1 to this paragraph 
(k)(4)(v)(A). Specifically, for each of the CVP tests listed in the 
first column for which either the capacity tolerances of paragraph 
(k)(4)(iii)(B) or (C) of this section are not met or the efficiency 
tolerances of paragraph (k)(4)(iii)(D) of this section are not met, the 
certification tests to be conducted again using the compressor speed 
determined in the corresponding CVP test are listed in the last three 
columns of the table, depending on which of the three kinds of system 
the model is designated.
    (2) If required, the adjusted qH3,Full and PH3,Full shall be used 
to calculate qk=2hcalc(47) and Pk=2hcalc(47), respectively, to 
represent performance at 47 [deg]F as described in section 11.2.2.4 of 
AHRI 210/240-2024 (if testing in accordance with appendix M1 to subpart 
B of 10 CFR part 430; (incorporated by reference, see Sec.  429.4)) or 
of AHRI 1600-2024 (if testing in accordance with appendix M2 to subpart 
B of 10 CFR part 430; (incorporated by reference, see Sec.  429.4)) and 
for use in calculating performance at 35 [deg]F. If required, the 
adjusted H1Low and H3Low tests shall be used to calculate qthi,H2,Low 
and PH2,Low, respectively, as described in section 6.1.3.4 of AHRI 210/
240-2024 (if testing in accordance with appendix M1 to subpart B of 10 
CFR part 430; (incorporated by reference, see Sec.  429.4)) or of AHRI 
1600-2024 (if testing in accordance with appendix M2 to subpart B of 10 
CFR part 430; (incorporated by reference, see Sec.  429.4)). No 
adjustments are required for intermediate or nominal compressor speed 
tests or, if cyclic tests are conducted, for the degradation 
coefficient(s).

[[Page 1281]]



                                        Table 1 to Paragraph (k)(4)(v)(A)
----------------------------------------------------------------------------------------------------------------
                                        Certification tests that use the indicated CVP test compressor speed or
                                       would have certification test results adjusted per paragraph (k)(4)(v)(B)
                                        of this section, if the CVP test is out of capacity or EER/COP tolerance
                                                       per paragraph (k)(4)(iii) of this section
               CVP test               --------------------------------------------------------------------------
                                          Variable capacity        Variable capacity
                                          certified, single     certified, two capacity     Variable capacity
                                           capacity system               system                   system
----------------------------------------------------------------------------------------------------------------
AFull................................  AFull, BFull...........  AFull, BFull...........  AFull, BFull.
FLow.................................  N/A....................  BLow, FLow.............  BLow, FLow.
H1Low................................  N/A....................  H0Low, H1Low, H3Low....  H0Low, H1Low.
H3Full...............................  H2Full, H3Full.........  H3Full.................  H3Full.
H4Full...............................  H4Full.................  H4Full.................  H4Full.
----------------------------------------------------------------------------------------------------------------

    (B) The instructions of this paragraph shall be applied to systems 
for which the means for overriding the compressor and indoor blower 
speed as discussed in paragraph (k)(4)(v)(A) of this section is not 
provided by the control used for conducting the CVP. For each of the 
CVP tests listed in the first column of table 1 to paragraph 
(k)(4)(v)(A) of this section for which either the capacity tolerances 
of paragraph (k)(4)(iii)(B) or (C) of this section are not met or the 
efficiency tolerances of paragraph (k)(4)(iii)(D) of this section are 
not met, depending on which of the three kinds of system the model is 
designated, the certification test results to be adjusted based on the 
results of the CVP test are indicated by the last three columns of the 
table for each CVP test listed in the first column.
    (1) The average capacities and power(s) measured during the CVP 
time period(s) described in paragraph (k)(4)(iii)(A) of this section 
shall be used (with no adjustment for tests having a CVP interval). For 
the certification tests requiring adjustment with no CVP interval (any 
required certification test in column 2, 3, or 4 of table 1 to 
paragraph (k)(4)(v)(A) of this section other than AFull, 
FLow, H1Low, H3Full and 
H4Full for which the column 1 CVP interval did not meet 
capacity or EER2/COP2/EER/COP tolerances), the capacity and power shall 
be adjusted. The capacity shall be adjusted by applying the ratio of 
the capacity measured during the CVP test interval divided by the 
capacity measured during the certification test (for the corresponding 
CVP interval). The power shall be adjusted by applying the ratio of the 
power measured during the CVP test interval divided by the power 
measured during the certification test (for the corresponding CVP 
interval), as follows:
    Cooling full capacity:
    [GRAPHIC] [TIFF OMITTED] TR07JA25.020
    
    Cooling full power:
    [GRAPHIC] [TIFF OMITTED] TR07JA25.021
    
    Cooling minimum capacity:
    [GRAPHIC] [TIFF OMITTED] TR07JA25.022
    
    Cooling minimum power:
    [GRAPHIC] [TIFF OMITTED] TR07JA25.023
    
    Heating minimum capacity:

[[Page 1282]]

[GRAPHIC] [TIFF OMITTED] TR07JA25.024

    Heating minimum power:
    [GRAPHIC] [TIFF OMITTED] TR07JA25.025
    
Where:

CSF = 0.0204/[deg]F, capacity slope factor for Split Systems
CSF = 0.0262/[deg]F, capacity slope factor for Single Package Units
PSF = 0.00455/[deg]F, power slope factor for all products

    (2) If required, the measured QH3,Full and EH3,Full from the CVP 
shall be used to calculate qk=2hcalc(47) and Pk=2hcalc(47), 
respectively, to represent performance at 47 [deg]F as described in 
section 11.2.2.4 of AHRI 210/240-2024 (if testing in accordance with 
appendix M1 to subpart B of 10 CFR part 430; (incorporated by 
reference, see Sec.  429.4)) or of AHRI 1600-2024 (if testing in 
accordance with appendix M2; (incorporated by reference, see Sec.  
429.4)), and for use in calculating performance at 35 [deg]F. If 
required, the measured H1Low from the CVP and the adjusted H3Low tests 
shall be used to calculate qthi,H2,Low and PH2,Low, respectively, as 
described in section 6.1.3.4 of AHRI 210/240-2024 (if testing in 
accordance with appendix M1 to subpart B of 10 CFR part 430; 
(incorporated by reference, see Sec.  429.4)) or of AHRI 1600-2024 (if 
testing in accordance with appendix M2 to subpart B of 10 CFR part 430; 
(incorporated by reference, see Sec.  429.4)). No adjustments are 
required for intermediate or nominal compressor speed tests or, if 
cyclic tests are conducted, the degradation coefficient(s).
    (C) If the test unit is determined to be variable capacity 
certified, single capacity system, or variable capacity certified, two 
capacity system and is not certified or marketed for use with only a 
proprietary control device, the same simulated thermostat low voltage 
signal that resulted in full speed compressor operation for the full 
load intervals shall be used for all certification full load tests. If 
the test unit is determined to be variable capacity certified, two 
capacity system and is not certified or marketed for use with only a 
proprietary control device the same simulated thermostat low voltage 
signal that resulted in low-speed compressor operation for the low load 
intervals shall be used for all certification low load tests.
* * * * *

PART 430--ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS

0
6. 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
7. Amend Sec.  430.2 by revising the definition of ``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 Sec.  
431.92 of this chapter, 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).
* * * * *

0
8. Amend Sec.  430.3 by:
0
a. Removing ``appendices M and M1'' and adding in its place ``appendix 
M'' in paragraph (b)(4) introductory text;
0
b. Revising paragraphs (c) and (g)(1) through (3);
0
c. Removing ``appendices M and M1'' and adding in its place ``appendix 
M'' in paragraphs (g)(4) introductory text and (g)(21);
0
d. Redesignating paragraphs (g)(22) through (24) as paragraphs (g)(23) 
through (25); and
0
e. Adding new paragraph (g)(22).
    The revisions and addition read as follows:


Sec.  430.3  Materials incorporated by reference.

* * * * *
    (c) AHRI. Air-Conditioning, Heating, and Refrigeration Institute, 
2311 Wilson Blvd., Suite 400, Arlington, VA 22201, (703) 524-8800, or 
go to: www.ahrinet.org.
    (1) 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 (Addendum 1 dated June 2011 and Addendum 2 dated March 2012); 
IBR approved for appendix M to subpart B, as follows:
    (i) Section 6--Rating Requirements, Section 6.1--Standard Ratings, 
6.1.3--Standard Rating Tests, 6.1.3.2--Electrical Conditions;

[[Page 1283]]

    (ii) Section 6--Rating Requirements, Section 6.1--Standard Ratings, 
6.1.3--Standard Rating Tests, 6.1.3.4--Outdoor-Coil Airflow Rate;
    (iii) Section 6--Rating Requirements, Section 6.1--Standard 
Ratings, 6.1.3--Standard Rating Tests, 6.1.3.5--Requirements for 
Separated Assemblies;
    (iv) Figure D1--Tunnel Air Enthalpy Test Method Arrangement;
    (v) Figure D2--Loop Air Enthalpy Test Method Arrangement; and
    (vi) Figure D4--Room Air Enthalpy Test Method Arrangement.
    (2) AHRI Standard 210/240-2024 (I-P), (``AHRI 210/240-2024''), 
Performance Rating of Unitary Air-conditioning and Air-source Heat Pump 
Equipment; IBR approved for appendix M1 to subpart B.
    (3) AHRI Standard 1160-2009 (``AHRI 1160''), Performance Rating of 
Heat Pump Pool Heaters, 2009; IBR approved for appendix P to subpart B.
    (4) 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 (including 
Addendum 1 dated March 2011), ANSI approved August 2, 2010 (Addendum 2 
dated June 2014); IBR approved for appendix M to subpart B, as follows:
    (i) Section 3--Definitions (except 3.8, 3.9, 3.13, 3.14, 3.15, 
3.16, 3.23, 3.24, 3.26, 3.27, 3.28, 3.29, 3.30, and 3.31);
    (ii) Section 5--Test Requirements, Section 5.1 (untitled), 5.1.3-
5.1.4;
    (iii) Section 6--Rating Requirements, Section 6.1--Standard 
Ratings, 6.1.5--Airflow Requirements for Systems with Capacities 
<65,000 Btu/h [19,000 W];
    (iv) Section 6--Rating Requirements, Section 6.1--Standard Ratings, 
6.1.6--Outdoor-Coil Airflow Rate (Applies to all Air-to-Air Systems);
    (v) Section 6--Rating Requirements, Section 6.2--Conditions for 
Standard Rating Test for Air-cooled Systems <65,000 Btu/h [19,000W] 
(except table 8); and
    (vi) Table 4--Refrigerant Line Length Correction Factors.
    (5) AHRI Standard 1600-2024 (I-P) (``AHRI 1600-2024''), Performance 
Rating of Unitary Air-conditioning and Air-source Heat Pump Equipment; 
IBR approved for appendix M2 to subpart B.
* * * * *
    (g) * * *
    (1) ANSI/ASHRAE Standard 16-2016 (``ANSI/ASHRAE 16''), Method of 
Testing for Rating Room Air Conditioners, Packaged Terminal Air 
Conditioners, and Packaged Terminal Heat Pumps for Cooling and Heating 
Capacity, ANSI approved November 1, 2016; IBR approved for appendices 
F, M1, and M2 to subpart B.
    (2) 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; IBR 
approved for appendix M to subpart B, as follows:
    (i) Section 5--Requirements;
    (ii) Section 6--Instruments;
    (iii) Section 7--Methods of Testing; and
    (iv) Section 8--Compressor Testing.
    (3) ANSI/ASHRAE Standard 37-2009, (``ASHRAE 37-2009''), Methods of 
Testing for Rating Electrically Driven Unitary Air-Conditioning and 
Heat Pump Equipment, ANSI approved June 25, 2009; IBR approved for 
appendices CC, CC1, M1, and M2 to subpart B.
* * * * *
    (22) ANSI/ASHRAE Standard 116-2010, (``ANSI/ASHRAE 116-2010''), 
Methods of Testing for Rating Seasonal Efficiency of Unitary Air 
Conditioners and Heat Pumps, ANSI approved February 24, 2010, IBR 
approved for appendices M1 and M2 to subpart B.
* * * * *

0
9. Amend Sec.  430.23 by revising paragraph (m) to read as follows:


Sec.  430.23  Test procedures for the measurement of energy and water 
consumption.

* * * * *
    (m) Central air conditioners and heat pumps. See the note at the 
beginning of appendices M1 and M2 to this subpart to determine the 
appropriate test method. Determine all values discussed in this section 
using a single appendix.
    (1) Determine cooling capacity from the steady-state wet-coil test 
(A or Afull Test), as per instructions in section 2 of 
appendix M1 or M2 to this subpart, and rounded off to the nearest:
    (i) To the nearest 50 Btu/h if cooling capacity is less than 20,000 
Btu/h;
    (ii) To the nearest 100 Btu/h if cooling capacity is greater than 
or equal to 20,000 Btu/h but less than 38,000 Btu/h; and
    (iii) To the nearest 250 Btu/h if cooling capacity is greater than 
or equal to 38,000 Btu/h and less than 65,000 Btu/h.
    (2) Determine seasonal energy efficiency ratio 2 (SEER2) as 
described in sections 2 and 5 of appendix M1 to this subpart or 
seasonal cooling and off-mode rating efficiency (SCORE) as described in 
sections 2 and 4 of appendix M2 to this subpart, and round off to the 
nearest 0.025 Btu/W-h.
    (3) Determine energy efficiency ratio 2 (EER2) as described in 
section 2 of appendix M1 or energy efficiency ratio (EER) as described 
in section 2 of appendix M2 to this subpart and round off to the 
nearest 0.025 Btu/W-h. EER2 (for appendix M1 to this subpart) or EER 
(for appendix M2 to this subpart) is the efficiency from the A or 
Afull test, whichever applies.
    (4) Determine heating seasonal performance factor 2 (HSPF2) as 
described in sections 2 and 5 of appendix M1 to this subpart or 
seasonal heating and off-mode rating efficiency (SHORE) as described in 
sections 2 and 4 of appendix M2 to this subpart, and round off to the 
nearest 0.025 Btu/W-h.
    (5) Determine PW,OFF, average off-mode power 
consumption, as described in section 3 of appendix M1 to this subpart, 
and round off to the nearest 0.5 W. Average off-mode power consumption 
is not required when testing in accordance with appendix M2 to this 
subpart.
    (6) Determine all other measures of energy efficiency or 
consumption or other useful measures of performance using appendix M1 
or M2 of this subpart.
* * * * *

0
10. Revise appendix M1 to subpart B of part 430 to 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

    Note: Prior to July 7, 2025, representations with respect to the 
energy use or efficiency of central air conditioners and heat pumps, 
including compliance certifications, must be based on testing 
conducted in accordance with:
    (a) Appendix M1 to this subpart, in the 10 CFR parts 200 through 
499 edition revised as of January 1, 2023; or
    (b) This appendix M1.
    Beginning July 7, 2025, and prior to the compliance date of 
amended standards for central air conditioners and heat pumps based 
on Seasonal Cooling and Off-mode Rating Efficiency (SCORE) and 
Seasonal Heating and Off-mode Rating Efficiency (SHORE), 
representations with respect to energy use or efficiency of central 
air conditioners and heat pumps, including compliance 
certifications, must be based on testing conducted in accordance 
with this appendix.
    Beginning on the compliance date of amended standards for 
central air conditioners and heat pumps based on SCORE and SHORE, 
representations with respect to energy use or efficiency of central 
air conditioners and heat pumps, including compliance 
certifications, must be based on testing conducted in accordance 
with appendix M2 to this subpart.

[[Page 1284]]

    Manufacturers may also certify compliance with any amended 
energy conservation standards for central air conditioners and heat 
pumps based on SCORE or SHORE prior to the applicable compliance 
date for those standards, and those compliance certifications must 
be based on testing in accordance with appendix M2 to this subpart.

1. Incorporation by Reference

    In Sec.  430.3, DOE incorporated by reference the entire 
standard for AHRI 210/240-2024, ANSI/ASHRAE 16, ASHRAE 37-2009 and 
ANSI/ASHRAE 116-2010. However, certain enumerated provisions of AHRI 
210/240-2024, ANSI/ASHRAE 16, ASHRAE 37-2009 and ANSI/ASHRAE 116-
2010, as set forth in sections 1.1 through 1.4 of this appendix, are 
inapplicable. To the extent there is a conflict between the terms or 
provisions of a referenced industry standard and the CFR, the CFR 
provisions control.

1.1. AHRI 210/240-2024

    (a) Section 1 Purpose is inapplicable,
    (b) Section 2 Scope is inapplicable,
    (c) The following subsections of Section 3 Definitions are 
inapplicable: 3.2.16 (Double-duct system), 3.2.20 (Gross capacity), 
3.2.46 (Oil Recovery Mode), 3.2.51 (Published Rating), 3.2.63 
(Standard Filter), 3.2.78 (Unitary Air-conditioner), 3.2.79 (Unitary 
Heat Pump),
    (d) Section 4 Classifications is inapplicable,
    (e) The following subsection of Section 5 Test Requirements is 
inapplicable: 5.1.6.2 (Outdoor Unit with No Match (OUWNM)),
    (f) The following subsections of Section 6 Rating Requirements 
are inapplicable: 6.1.8, 6.2, 6.3, 6.4 and 6.5
    (g) Section 7 Minimum Data Requirements for Published Ratings is 
inapplicable,
    (h) Section 8 Operating Requirements is inapplicable,
    (i) Section 9 Marking and Nameplate Data is inapplicable,
    (j) Section 10 Conformance Conditions is inapplicable,
    (k) Appendix A References--Normative is inapplicable,
    (l) Appendix B References--Informative is inapplicable,
    (m) Appendix C Secondary Capacity Check Requirements--Normative 
is inapplicable,
    (n) Appendix F Unit Configurations for Standard Efficiency 
Determination--Normative is inapplicable,
    (o) Appendix H Verification Testing--Normative is inapplicable,
    (p) Appendix I Controls Verification Procedure--Normative is 
inapplicable, and
    (q) Appendix J Determination of Cut in and Cut out 
temperatures--Normative is inapplicable.

1.2. ANSI/ASHRAE 37-2009

    (a) Section 1--Purpose is inapplicable,
    (b) Section 2--Scope is inapplicable, and
    (c) Section 4--Classification is inapplicable.

1.3. ANSI/ASHRAE 16-2016

    (a) Section 1--Purpose is inapplicable,
    (b) Section 2--Scope is inapplicable, and
    (c) Section 4--Classification is inapplicable.

1.4. ANSI/ASHRAE 116-2010

    (a) Section 1--Purpose is inapplicable,
    (b) Section 2--Scope is inapplicable,
    (c) Section 4--Classification is inapplicable,
    (d) Section 7--Methods of Test is inapplicable,
    (e) References is inapplicable,
    (f) Appendix A--Example Bin Calculations is inapplicable, and
    (g) Appendix B--Bibliography is inapplicable.

2. General

    Determine the cooling capacity, heating capacity, and applicable 
energy efficiency metrics (SEER2, HSPF2, and EER2) in accordance 
with the specified sections of AHRI 210/240-2024 and the applicable 
provisions of ANSI/ASHRAE 16, ASHRAE 37-2009, and ANSI/ASHRAE 116-
2010. The AFull (cooling mode) and H1Full or 
H1Nom (heating mode, if applicable) shall have a 
secondary capacity check completed. For all other tests in each 
mode, it is permissible to not use a secondary capacity check. For 
cooling mode tests of variable capacity systems, the compressor 
shall operate at the same cooling full speed, measured by RPM of 
power input frequency (Hz), for both AFull and 
BFull tests. Additionally, the compressor shall operate 
at the same cooling minimum speed, measured by RPM or power input 
frequency (Hz), for the BLow, FLow, 
GLow, and ILow tests.
    Sections 3, 4, and 5 of this appendix provide additional 
instructions for testing. In cases where there is a conflict, the 
language of this appendix takes highest precedence, followed, in 
order, by: AHRI 210/240-2024, ASHRAE 37-2009, ANSI/ASHRAE 16 and 
ANSI/ASHRAE 116-2010. Any subsequent amendment to a referenced 
document by the standard-setting organization will not affect the 
test procedure in this appendix, unless and until the test procedure 
is amended by DOE. Material is incorporated as it exists on the date 
of the approval, and a notice of any change in the incorporation 
will be published in the Federal Register.

3. Off-Mode Power

    Determine off-mode power, PW, OFF, in accordance with 
section 11.3 and appendix G of AHRI 210/240-2024.

4. Outdoor Units With No Match (OUWNM)

    4.1. Definition. An Outdoor Unit that is not distributed in 
commerce with any indoor units, that meets any of the following 
criteria:
    (a) Is designed for use with a refrigerant that makes the unit 
banned for installation when paired with a new Indoor Unit to create 
a new system, according to EPA regulations in 40 CFR chapter I, 
subchapter C,
    (b) Is designed for use with a refrigerant that has a 95 [deg]F 
midpoint saturation absolute pressure that is 18 percent 
of the 95 [deg]F saturation absolute pressure for R-22 and global 
warming potential greater than 150 per EPA regulations in 40 CFR 
84.64, or
    (c) Is shipped without a specified refrigerant from the point of 
manufacture or is shipped such that more than two pounds of 
refrigerant are required to meet the charge per section 5.1.8 of 
AHRI 210/240-2024. This shall not apply if either:
    (1) The factory charge is equal to or greater than 70% of the 
outdoor unit internal volume times the liquid density of refrigerant 
at 95 [deg]F, or
    (2) An A2L refrigerant is approved for use and listed in the 
certification report.
    4.2. Testing. An OUWNM shall be tested at a single cooling air 
volume rate with an indoor coil having nominal tube diameter of 
0.375 in and an NGIFS of 1.0 or less (as determined in section 
5.1.6.3 of AHRI 210/240-2024). Tested values of CD\c\ and/or CD\h\ 
are not permitted. The default value, 0.25, shall be used for both 
cooling and heating mode testing.

5. Test Conditions

    5.1. Test Conditions for Certifying Compliance with Standards. 
The following conditions specified in AHRI 210/240-2024 apply when 
testing to certify to the SEER2 and HSPF2 energy conservation 
standards in Sec.  430.32(c).
    (a) For cooling mode, use the rating conditions specified in 
table 8 of AHRI 210/240-2024 and the fractional cooling bin hours in 
table 15 of AHRI 210/240-2024 to determine SEER2, and EER2 for 
models subject to regional standards in terms of EER2.
    (b) For heat pump heating mode, use the rating conditions 
specified in table 8 of AHRI 210/240-2024 and the fractional heating 
bin hours specified for Region IV in table 16 of AHRI 210/240-2024 
to determine the heating efficiency metric, HSPF2.
    5.2. Optional Representations. Representations of EER2 made 
using the rating conditions specified in table 8 of AHRI 210/240-
2024 are optional for models not subject to regional standards in 
terms of EER2. Representations of HSPF2 made using the rating 
conditions specified in table 8 of AHRI 210/240-2024 and the 
fractional heating hours specified for Regions other than Region IV 
in table 16 of AHRI 210/240-2024 are optional. Representations of 
COPpeak made using appendix K are optional.


0
11. Add appendix M2 to subpart B of part 430 to read as follows:

Appendix M2 to Subpart B of Part 430--Uniform Test Method for Measuring 
the Energy Consumption of Central Air Conditioners and Heat Pumps

    Note: Prior to July 7, 2025, representations with respect to the 
energy use or efficiency of central air conditioners and heat pumps, 
including compliance certifications, must be based on testing 
conducted in accordance with:
    (a) Appendix M1 to this subpart, in the 10 CFR parts 200 through 
499 edition revised as of January 1, 2023; or
    (b) Appendix M1 to this subpart.
    Beginning July 7, 2025, and prior to the compliance date of 
amended standards for central air conditioners and heat pumps based 
on Seasonal Cooling and Off-mode Rating Efficiency (SCORE) and 
Seasonal Heating and Off-mode Rating Efficiency (SHORE), 
representations with respect to energy use or efficiency of central 
air conditioners and heat pumps, including

[[Page 1285]]

compliance certifications, must be based on testing conducted in 
accordance with appendix M1 to this subpart.
    Beginning on the compliance date of amended standards for 
central air conditioners and heat pumps based on SCORE and SHORE, 
representations with respect to energy use or efficiency of central 
air conditioners and heat pumps, including compliance 
certifications, must be based on testing conducted in accordance 
with this appendix.
    Manufacturers may also certify compliance with any amended 
energy conservation standards for central air conditioners and heat 
pumps based on SCORE or SHORE prior to the applicable compliance 
date for those standards, and those compliance certifications must 
be based on testing in accordance with this appendix.

1. Incorporation by Reference

    In Sec.  430.3, DOE incorporated by reference the entire 
standard for AHRI 1600-2024, ANSI/ASHRAE 16, ASHRAE 37-2009, and 
ANSI/ASHRAE 116-2010. However, certain enumerated provisions of AHRI 
1600-2024, ANSI/ASHRAE 16, ASHRAE 37-2009, and ANSI/ASHRAE 116-2010, 
as set forth in sections 1.1 through 1.4 of this appendix, are 
inapplicable. To the extent there is a conflict between the terms or 
provisions of a referenced industry standard and the CFR, the CFR 
provisions control.

1.1. AHRI 1600-2024

    (a) Section 1 Purpose is inapplicable,
    (b) Section 2 Scope is inapplicable,
    (c) The following sections of Section 3 Definitions are 
inapplicable: 3.2.16 (Double-duct system), 3.2.20 (Gross capacity), 
3.2.45 (Oil Recovery Mode), 3.2.50 (Published Rating), 3.2.63 
(Standard Filter), 3.2.78 (Unitary Air-conditioner), 3.2.79 (Unitary 
Heat Pump),
    (d) Section 4 Classifications is inapplicable,
    (e) The following subsection of Section 5 Test Requirements is 
inapplicable: 5.1.6.2 (Outdoor Unit with No Match (OUWNM)),
    (f) The following subsections of Section 6 Rating Requirements 
are inapplicable: 6.1.8, 6.2, 6.3, 6.4 and 6.5
    (g) Section 7 Minimum Data Requirements for Published Ratings is 
inapplicable,
    (h) Section 8 Operating Requirements is inapplicable,
    (i) Section 9 Marking and Nameplate Data is inapplicable,
    (j) Section 10 Conformance Conditions is inapplicable,
    (k) Appendix A References--Normative is inapplicable,
    (l) Appendix B References--Informative is inapplicable,
    (m) Appendix C Secondary Capacity Check Requirements--Normative 
is inapplicable,
    (n) Appendix F Unit Configurations for Standard Efficiency 
Determination--Normative is inapplicable,
    (o) Appendix H Verification Testing--Normative is inapplicable,
    (p) Appendix I Controls Verification Procedure--Normative is 
inapplicable, and
    (q) Appendix J Determination of Cut in and Cut out 
temperatures--Normative is inapplicable.

1.2. ANSI/ASHRAE 37-2009

    (a) Section 1--Purpose is inapplicable,
    (b) Section 2--Scope is inapplicable, and
    (c) Section 4--Classification is inapplicable.

1.3. ANSI/ASHRAE 16-2016

    (a) Section 1--Purpose is inapplicable,
    (b) Section 2--Scope is inapplicable, and
    (c) Section 4--Classification is inapplicable.

1.4. ANSI/ASHRAE 116-2010

    (a) Section 1--Purpose is inapplicable,
    (b) Section 2--Scope is inapplicable,
    (c) Section 4--Classification is inapplicable,
    (d) Section 7--Methods of Test is inapplicable,
    (e) References is inapplicable,
    (f) Appendix A--Example Bin Calculations is inapplicable, and
    (g) Appendix B--Bibliography is inapplicable.

2. General

    Determine the applicable energy efficiency metrics (SCORE, 
SHORE, and EER) in accordance with the specified sections of AHRI 
1600-2024 and the applicable provisions of ANSI/ASHRAE 16, ASHRAE 
37-2009, and ANSI/ASHRAE 116-2010. The AFull (cooling 
mode) and H1Full or H1Nom (heating mode, if 
applicable) shall have a secondary capacity check completed. For all 
other tests in each mode, it is permissible to not use a secondary 
capacity check. For cooling mode tests of variable capacity systems, 
the compressor shall operate at the same cooling full speed, 
measured by RPM of power input frequency (Hz), for both 
AFull and BFull tests. Additionally, the 
compressor shall operate at the same cooling minimum speed, measured 
by RPM or power input frequency (Hz), for the BLow, 
FLow, GLow, and ILow tests.
    Sections 3 and 4 of this appendix provide additional 
instructions for testing. In cases where there is a conflict, the 
language of this appendix takes highest precedence, followed, in 
order, by: AHRI 1600-2024, ASHRAE 37-2009, ANSI/ASHRAE 16, and ANSI/
ASHRAE 116-2010. Any subsequent amendment to a referenced document 
by the standard-setting organization will not affect the test 
procedure in this appendix, unless and until the test procedure is 
amended by DOE. Material is incorporated as it exists on the date of 
the approval, and a notice of any change in the incorporation will 
be published in the Federal Register.

3. Outdoor Units With No Match (OUWNM)

    3.1. Definition. An Outdoor Unit that is not distributed in 
commerce with any indoor units, that meets any of the following 
criteria:
    (a) Is designed for use with a refrigerant that makes the unit 
banned for installation when paired with a new Indoor Unit as a 
system, according to EPA regulations in 40 CFR chapter I, subchapter 
C,
    (b) Is designed for use with a refrigerant that has a 95 [deg]F 
midpoint saturation absolute pressure that is 18 percent 
of the 95 [deg]F saturation absolute pressure for R-22 and a global 
warming potential greater than 150 per EPA regulations in 40 CFR 
84.64, or
    (c) Is shipped without a specified refrigerant from the point of 
manufacture or is shipped such that more than two pounds of 
refrigerant are required to meet the charge per section 5.1.8 of 
AHRI 1600-2024. This shall not apply if either:
    (1) The factory charge is equal to or greater than 70% of the 
outdoor unit internal volume times the liquid density of refrigerant 
at 95 [deg]F or,
    (2) An A2L refrigerant is approved for use and listed in the 
certification report
    3.2. Testing. An OUWNM shall be tested at a single cooling air 
volume rate with an indoor coil having nominal tube diameter of 
0.375 in and an NGIFS of 1.0 or less (as determined in section 
5.1.6.3 of AHRI 1600-2024). Tested values of CD\c\ and/or CD\h\ are 
not permitted. The default value, 0.25, shall be used for both 
cooling and heating mode testing.

4. Test Conditions

    4.1. Test Conditions for Certifying Compliance with Standards. 
The following conditions specified in AHRI 1600-2024 apply if 
testing to certify to the SCORE and SHORE energy conservation 
standards in Sec.  430.32(c).
    (a) For cooling mode, use the rating conditions specified in 
table 8 of AHRI 1600-2024 and the `U.S. National Average' cooling 
conditioning hours and shoulder season hours in table 15 of AHRI 
1600-2024, to determine SCORE, and EER for models subject to 
regional standards in terms of EER.
    (b) For heat pump heating mode, use the rating conditions 
specified in table 8 of AHRI 1600-2024 and the `U.S. National 
Average' heating conditioning hours and shoulder season hours 
specified in table 18 of AHRI 1600-2024 to determine the heating 
efficiency metric, SHORE.
    4.2. Optional Representations. Representations of EER made using 
the rating conditions specified in table 8 of AHRI 1600-2024 are 
optional for models not subject to regional standards in terms of 
EER. Representations of SHORE made using the rating conditions 
specified in table 8 of AHRI 1600-2024 and the `Cold Climate 
Average' heating conditioning hours and shoulder season hours in 
table 18 of AHRI 1600-2024 are optional. Representations of 
COPpeak made using appendix K are optional.

[FR Doc. 2024-30852 Filed 1-6-25; 8:45 am]
BILLING CODE 6450-01-P`