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Rule2022-22511

Energy Conservation Program: Test Procedure for VRF Multi-Split Systems

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Published

October 20, 2022

Effective

November 21, 2022

Issuing agencies

Energy Department

Abstract

This final rule amends the test procedure for variable refrigerant flow ("VRF") multi-split air conditioners and heat pumps ("VRF multi-split systems") to incorporate by reference the latest version of the applicable industry test standard. This final rule also adopts the integrated energy efficiency ratio metric in its test procedures for VRF multi-split systems. Additionally, this final rule adopts provisions in the updated industry test procedure relevant to certification and enforcement, including a controls verification procedure.

Full Text

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<title>Federal Register, Volume 87 Issue 202 (Thursday, October 20, 2022)</title>
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[Federal Register Volume 87, Number 202 (Thursday, October 20, 2022)]
[Rules and Regulations]
[Pages 63860-63901]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2022-22511]

[[Page 63859]]

Vol. 87

Thursday,

No. 202

October 20, 2022

Part II

Department of Energy

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10 CFR Parts 429 and 431

Energy Conservation Program: Test Procedure for VRF Multi-Split
Systems; Final Rule

Federal Register / Vol. 87 , No. 202 / Thursday, October 20, 2022 /
Rules and Regulations

[[Page 63860]]

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DEPARTMENT OF ENERGY

10 CFR Parts 429 and 431

[EERE-2021-BT-TP-0019]
RIN 1904-AE43

Energy Conservation Program: Test Procedure for VRF Multi-Split
Systems

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

ACTION: Final rule.

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SUMMARY: This final rule amends the test procedure for variable
refrigerant flow (``VRF'') multi-split air conditioners and heat pumps
(``VRF multi-split systems'') to incorporate by reference the latest
version of the applicable industry test standard. This final rule also
adopts the integrated energy efficiency ratio metric in its test
procedures for VRF multi-split systems. Additionally, this final rule
adopts provisions in the updated industry test procedure relevant to
certification and enforcement, including a controls verification
procedure.

DATES: The effective date of this rule is November 21, 2022. The final
rule changes will be mandatory for VRF multi-split systems equipment
testing October 16, 2023. The incorporation by reference of certain
publications listed in this rule is approved by the Director of the
Federal Register on November 21, 2022. The incorporation by reference
of certain other publications listed in this rule was approved by the
Director of the Federal Register as of July 30, 2015, and July 16,
2012.

ADDRESSES: The docket, which includes Federal Register notices, public
meeting webinar attendee lists and transcripts, comments, and other
supporting documents/materials, is available for review at
<a href="http://www.regulations.gov">www.regulations.gov</a>. All documents in the docket are listed in the
<a href="http://www.regulations.gov">www.regulations.gov</a> index. However, some documents listed in the index,
such as those containing information that is exempt from public
disclosure, may not be publicly available.
A link to the docket web page can be found at <a href="http://www.regulations.gov/docket/EERE-2021-BT-TP-0019">www.regulations.gov/docket/EERE-2021-BT-TP-0019</a>. 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: <a href="/cdn-cgi/l/email-protection#5d1c2d2d31343c333e380e293c33393c2f392e0c28382e293432332e1d383873393238733a322b">[email&#160;protected]</a>.

FOR FURTHER INFORMATION CONTACT:
Ms. Catherine Rivest, U.S. Department of Energy, Office of Energy
Efficiency and Renewable Energy, Building Technologies Office, EE-5B,
1000 Independence Avenue SW, Washington, DC 20585-0121. Telephone:
(202) 586-7335. Email: <a href="/cdn-cgi/l/email-protection#d190a1a1bdb8b0bfb2b482a5b0bfb5b0a3b5a280a4b4a2a5b8bebfa291b4b4ffb5beb4ffb6bea7">[email&#160;protected]</a>.
Mr. Eric Stas, U.S. Department of Energy, Office of the General
Counsel, GC-33, 1000 Independence Avenue SW, Washington, DC 20585-0121.
Telephone: (202) 586-5827. Email: <a href="/cdn-cgi/l/email-protection#195c6b707a374a6d786a597168377d767c377e766f">[email&#160;protected]</a>.

SUPPLEMENTARY INFORMATION: DOE incorporates by reference the following
industry standards as follows:

AHRI Standard 1230 (I-P), ``2021 Standard for Performance Rating of
Variable Refrigerant Flow (VRF) Multi-Split Air-Conditioning and Heat
Pump Equipment;'' copyright 2021 (``AHRI 1230-2021'')--into parts 429
and 431.
ANSI/AHRI 1230-2010, 2010 Standard for Performance Rating of Variable
Refrigerant Flow (VRF) Multi-Split Air-Conditioning and Heat Pump
Equipment,'' approved August 2, 2010 and updated by addendum 1 in March
2011 (``ANSI/AHRI 1230-2010'')--into part 431.

Copies of AHRI 1230-2021 and ANSI/AHRI 1230-2010 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: <a href="http://www.ahrinet.org/search-standards.aspx">www.ahrinet.org/search-standards.aspx</a>.

ANSIASHRAE Standard 37-2009, ``Methods of Testing for Rating
Electrically Driven Unitary Air-Conditioning and Heat Pump Equipment,''
ASHRAE approved June 24, 2009, (``ANSI/ASHRAE 37-2009'')--into part
431.
ASHRAE Errata Sheet for ANSI/ASHRAE Standard 37-2009--Methods of
Testing for Rating Electrically Driven Unitary Air-Conditioning and
Heat Pump Equipment, ASHRAE approved March 27, 2019, (``ASHRAE Errata
Sheet for ANSI/ASHRAE Standard 37-2009'').

Copies of ANSI/ASHRAE Standard 37-2009 and ASHRAE Errata Sheet for
ANSI/ASHRAE Standard 37-2009 are available from ASHRAE, 180 Technology
Parkway NW, Peachtree Corners, GA 30092, (404)-636-8400, or online at
<a href="http://www.ashrae.org/">www.ashrae.org/</a>.
See section IV.N of this document for a further discussion of these
standards.

Table of Contents

I. Authority and Background
A. Authority
B. Background
II. Synopsis of the Final Rule
III. Discussion
A. Scope of Applicability
B. Organization of the VRF Multi-Split System Test Procedure
C. Industry Standards
1. Updates to AHRI 1230
2. ASHRAE 37
D. Metrics
1. IEER
2. Test Conditions Used for Efficiency Metrics
E. Controls Verification Procedure
1. Background
2. When the CVP Is Conducted
3. Critical Parameter Definition
4. Validation of Certified Critical Parameters
a. Validation Time Period
b. Validation Criteria
5. Determination of Alternate Critical Parameters
F. Allowable Critical Parameter Adjustment
1. Adjustment of Certified Critical Parameter Values
2. Adjustment of Alternate Critical Parameter Values
G. Certification, Compliance, and Enforcement
1. Determination of Represented Values
a. Introduction
b. NOPR Proposals and Comments
c. Final Rule Approach
2. Certification Reporting Requirements
a. Certification Requirements
b. Supplemental Testing Instructions
3. Models Required for AEDM Validation
4. Manufacturer Involvement
a. Role of Manufacturer Representative
b. Control Tool
5. Break-In Period
6. Certified Critical Parameter Operational Settings
7. Enforcement Sampling Plan
8. Certified vs. Tested Performance
H. Effective and Compliance Dates
I. Test Procedure Costs
IV. Procedural Issues and Regulatory Review
A. Review Under Executive Orders 12866 and 13563
B. Review Under the Regulatory Flexibility Act
C. Review Under the Paperwork Reduction Act of 1995
D. Review Under the National Environmental Policy Act of 1969
E. Review Under Executive Order 13132
F. Review Under Executive Order 12988
G. Review Under the Unfunded Mandates Reform Act of 1995
H. Review Under the Treasury and General Government
Appropriations Act, 1999
I. Review Under Executive Order 12630
J. Review Under Treasury and General Government Appropriations
Act, 2001
K. Review Under Executive Order 13211
L. Review Under Section 32 of the Federal Energy Administration
Act of 1974
M. Congressional Notification
N. Description of Materials Incorporated by Reference
V. Approval of the Office of the Secretary

[[Page 63861]]

I. Authority and Background

Commercial package air conditioning and heating equipment is
included in the list of ``covered equipment'' 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.
6311(1)(B)-(D)) Commercial package air conditioning and heating
equipment includes variable refrigerant flow multi-split air
conditioners and heat pumps (``VRF multi-split systems''). DOE's energy
conservation standards and test procedure for VRF multi-split systems
are currently prescribed at 10 CFR 431.97 and 10 CFR 431.96,
respectively. The following sections discuss DOE's authority to
establish test procedures for VRF multi-split systems and relevant
background information regarding DOE's consideration of test procedures
for this equipment.

A. Authority

The Energy Policy and Conservation Act, as amended (``EPCA''),\1\
Public Law 94-163 (42 U.S.C. 6291-6317, as codified), among other
things, authorizes DOE to regulate the energy efficiency of a number of
consumer products and certain industrial equipment. Title III, Part C
\2\ of EPCA, added by Public Law 95-619, Title IV, section 441(a),
established the Energy Conservation Program for Certain Industrial
Equipment, which sets forth a variety of provisions designed to improve
energy efficiency. This equipment includes small, large, and very large
commercial package air conditioning and heating equipment, which
includes VRF multi-split systems, the subject of this document. (42
U.S.C. 6311(1)(B)-(D))
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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 reflect 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 C was redesignated as Part A-1.
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The energy conservation program under EPCA consists essentially of
four parts: (1) testing; (2) labeling; (3) Federal energy conservation
standards, and (4) certification and enforcement procedures. Relevant
provisions of EPCA include definitions (42 U.S.C. 6311), energy
conservation standards (42 U.S.C. 6313), test procedures (42 U.S.C.
6314), labeling provisions (42 U.S.C. 6315), and the authority to
require information and reports from manufacturers (42 U.S.C. 6316; 42
U.S.C. 6296).
The Federal testing requirements consist of test procedures that
manufacturers of covered equipment must use as the basis for: (1)
certifying to DOE that their equipment complies with the applicable
energy conservation standards adopted pursuant to EPCA (42 U.S.C.
6316(b); 42 U.S.C. 6296), and (2) making other representations about
the efficiency of that equipment (42 U.S.C. 6314(d)). Similarly, DOE
uses these test procedures to determine whether the equipment complies
with relevant standards promulgated under EPCA.
Federal energy efficiency requirements for covered equipment
established under EPCA generally supersede State laws and regulations
concerning energy conservation testing, labeling, and standards. (42
U.S.C. 6316(a) and (b); 42 U.S.C. 6297) DOE may, however, grant waivers
of Federal preemption for particular State laws or regulations, in
accordance with the procedures and other provisions of EPCA. (42 U.S.C.
6316(b)(2)(D))
Under 42 U.S.C. 6314, EPCA sets forth the criteria and procedures
DOE must follow when prescribing or amending test procedures for
covered equipment. EPCA requires that any test procedures prescribed or
amended under this section must be reasonably designed to produce test
results which reflect energy efficiency, energy use, or estimated
annual operating cost of a given type of covered equipment during a
representative average use cycle and requires that test procedures not
be unduly burdensome to conduct. (42 U.S.C. 6314(a)(2))
With respect to VRF multi-split systems, EPCA requires that the
test procedures shall be those generally accepted industry testing
procedures or rating procedures developed or recognized by AHRI or the
American Society of Heating, Refrigerating, and Air-Conditioning
Engineers (``ASHRAE''), as referenced in ASHRAE/IES Standard 90.1,
``Energy Standard for Buildings Except Low-Rise Residential Buildings''
(``ASHRAE Standard 90.1''). (42 U.S.C. 6314(a)(4)(A)) Further, if such
an industry test procedure is amended, DOE must amend its test
procedure to be consistent with the amended industry test procedure
unless DOE determines, by a rule published in the Federal Register and
supported by clear and convincing evidence, that the amended test
procedure would be unduly burdensome to conduct or would not produce
test results that reflect the energy efficiency, energy use, and
estimated operating costs of that equipment during a representative
average use cycle. (42 U.S.C. 6314(a)(4)(B))
EPCA also requires that, at least once every 7 years, DOE evaluate
test procedures for each type of covered equipment, including VRF
multi-split systems, to determine whether amended test procedures would
more accurately or fully comply with the requirements for the test
procedures to not be unduly burdensome to conduct and be reasonably
designed to produce test results that reflect energy efficiency, energy
use, and estimated operating costs during a representative average use
cycle. (42 U.S.C. 6314(a)(1))
In addition, if the Secretary determines that a test procedure
amendment is warranted, DOE must publish proposed test procedures in
the Federal Register and afford interested persons an opportunity (of
not less than 45 days' duration) to present oral and written data,
views, and comments on the proposed test procedures. (42 U.S.C.
6314(b)) If DOE determines that test procedure revisions are not
appropriate, DOE must publish in the Federal Register its determination
not to amend the test procedures. (42 U.S.C. 6314(a)(1)(A)(ii))
DOE is publishing this final rule amending the test procedure for
VRF multi-split systems in satisfaction of its statutory obligations
under EPCA.

B. Background

DOE's existing test procedure for VRF multi-split systems appears
at 10 CFR 431.96, ``Uniform test method for the measurement of energy
efficiency of commercial air conditioners and heat pumps.'' The Federal
test procedure for VRF multi-split systems was last amended in a final
rule for standards and test procedures for certain commercial heating,
air conditioning, and water heating equipment published in the Federal
Register on May 16, 2012 (``May 2012 Final Rule''). 77 FR 28928. With
regard to VRF multi-split systems, the May 2012 Final Rule adopted the
test procedure ANSI/AHRI 1230-2010, ``2010 Standard for Performance
Rating of Variable Refrigerant Flow (VRF) Multi-Split Air-Conditioning
and Heat Pump Equipment,'' approved August 2, 2010 and updated by
Addendum 1 in March 2011 (``ANSI/AHRI 1230-2010''). 77 FR 28928, 28945-
28946 (May 16, 2012); see 10 CFR 431.96, Table 1. Specifically, the DOE
test procedure for VRF multi-split systems was modified to reference
ANSI/AHRI 1230-2010 with Addendum 1 but omitting sections 5.1.2 and
6.6. 77 FR 28928, 28990-28991 (May 16, 2012). The May 2012 Final Rule
also adopted additional requirements, listed in 10 CFR 431.96(c)
through (f), for measuring the energy efficiency ratio (``EER'') and
coefficient of performance (``COP'') for air-cooled VRF multi-split
systems with a cooling

[[Page 63862]]

capacity between 65,000 Btu/h and 760,000 Btu/h and water-source VRF
multi-split systems with a cooling capacity less than 760,000 Btu/h.
Id. These additional requirements specify provisions for equipment set-
up and provide for limited involvement of manufacturer representatives
during testing. 77 FR 28928, 28991 (May 16, 2012).
In 2016,\3\ ASHRAE Standard 90.1 was updated, but the 2016 update
did not make changes to the test procedure references in ASHRAE
Standard 90.1-2013 for VRF multi-split systems. On July 25, 2017, DOE
published in the Federal Register a request for information (``RFI'')
(``July 2017 ASHRAE TP RFI'') to collect information and data to
consider amendments to DOE's test procedures for commercial package air
conditioning and heating equipment with the test procedure updates
included in ASHRAE Standard 90.1-2016. 82 FR 34427. As part of the July
2017 ASHRAE TP RFI, DOE requested comment on the VRF multi-split
systems test procedure, under the 7-year-lookback review requirement.
82 FR 34427, 34429 (July 25, 2017). DOE identified several issues that
might have warranted modifications to the applicable VRF multi-split
systems test procedure, in particular concerning incorporation by
reference of the most recent version of the relevant industry
standard(s); efficiency metrics and calculations; and clarification of
test methods. 82 FR 34427, 34427 (July 25, 2017).
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\3\ No publication date is printed on ASHRAE Standard 90.1-2016,
but ASHRAE issued a press release on October 26, 2016, which is
available at <a href="http://www.ashrae.org/news/2016/ashrae-ies-publish-2016-energy-efficiency-standard">www.ashrae.org/news/2016/ashrae-ies-publish-2016-energy-efficiency-standard</a> (Last accessed April 30, 2021).
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In September 2017, AHRI published an update to ANSI/AHRI 1230-2010,
i.e., ANSI/AHRI 1230-2014 with Addendum 1 (although published in 2017,
the update uses a 2014 designation).
On April 11, 2018, DOE published in the Federal Register a notice
of its intent to establish a negotiated rulemaking working group
(``Working Group'') under the Appliance Standards and Rulemaking
Federal Advisory Committee (``ASRAC''), in accordance with the Federal
Advisory Committee Act \4\ and the Negotiated Rulemaking Act,\5\ to
negotiate the proposed test procedure and amended energy conservation
standards for VRF multi-split systems. 83 FR 15514. The purpose of the
Working Group was to discuss and, if possible, reach consensus on a
proposed rule regarding the test procedure and energy conservation
standards for VRF multi-split systems, as authorized by EPCA. Id. at 83
FR 15514.
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\4\ 5 U.S.C. App. 2, Public Law 92-463.
\5\ 5 U.S.C. 561-570, Public Law 104-320.
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The Working Group comprised 21 voting members including
manufacturers, energy efficiency advocates, utilities, and trade
organizations.\6\ On October 1, 2019, the Working Group reached
consensus on a term sheet (``VRF TP Term Sheet''; Docket No. EERE-2018-
BT-STD-0003-0044) that includes the following recommendations, which
highlight the most substantial changes:
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\6\ A complete list of the ASRAC VRF Working Group members is
available at: <a href="http://www.energy.gov/eere/buildings/appliance-standards-and-rulemaking-federal-advisory-committee#Variable%20Refrigerant%20Flow%20Multi-Split%20Air%20Conditioners%20and%20Heat%20Pumps%20Working%20Group">www.energy.gov/eere/buildings/appliance-standards-and-rulemaking-federal-advisory-committee#Variable%20Refrigerant%20Flow%20Multi-Split%20Air%20Conditioners%20and%20Heat%20Pumps%20Working%20Group</a>.
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(1) VRF multi-split systems should be rated with the Integrated
Energy Efficiency Ratio (``IEER'') metric to allow consumers to make
consistent comparisons with rooftop air conditioner ratings.
(2) The amended test procedure should not be required until the
compliance date of amended energy conservation standards.
(3) The Federal test procedure for VRF multi-split systems should
be consistent with the September 20, 2019 draft version of AHRI 1230,
with additional amendments to be implemented after the conclusion of
ASRAC negotiations.

(Id. at pp. 1-3)
On May 18, 2021, AHRI published an updated industry test standard
for VRF multi-split systems AHRI Standard 1230 (I-P), ``2021 Standard
for Performance Rating of Variable Refrigerant Flow (VRF) Multi-Split
Air-Conditioning and Heat Pump Equipment'' (``AHRI 1230-2021''). AHRI
1230-2021 references ANSI/ASHRAE Standard 37-2009, ``Methods of Testing
for Rating Electrically Driven Unitary Air-Conditioning and Heat Pump
Equipment'' (``ANSI/ASHRAE 37-2009''), as corrected by the Errata Sheet
issued March 27, 2019, for additional test set-up and methodology
specifications.
These changes, along with comments received in response to the July
2017 ASHRAE TP RFI, were addressed in a test procedure NOPR for VRF
multi-split systems published in the Federal Register on December 10,
2021 (``December 2021 VRF TP NOPR''). 86 FR 70644. In that NOPR, DOE
proposed to incorporate by reference AHRI 1230-2021 and ANSI/ASHRAE 37-
2009, as corrected by the Errata Sheet issued March 27, 2019) and
establish provisions for determining IEER for VRF multi-split systems.
Id. DOE also proposed to update its certification, compliance, and
enforcement (``CCE'') provisions for VRF multi-split systems to provide
information that is necessary for testing VRF multi-split systems
consistent with the updated industry test procedure AHRI 1230-2021. DOE
held a public meeting related to this NOPR on January 20, 2022
(hereafter, the ``NOPR public meeting'').
DOE received comments in response to the December 2021 VRF TP NOPR
from the interested parties listed in Table I.1.

Table I-1--List of Commenters With Written Submissions in Response to the December 2021 VRF TP NOPR
----------------------------------------------------------------------------------------------------------------
Reference in this final Docket entry
Commenter(s) rule No. Commenter type
----------------------------------------------------------------------------------------------------------------
Air-Conditioning, Heating, & AHRI...................... 12 Trade Association.
Refrigeration Institute.
Appliance Standards Awareness Project, Joint Advocates........... 9 Efficiency Advocacy
American Council for an Energy- Organization.
Efficient Economy, and Natural
Resources Defense Council.
California Energy Commission............ CEC....................... 10 State Official/Agency.
California Investor-Owned Utilities..... CA IOUs................... 11 Utilities.
Carrier Global Corporation.............. Carrier................... 7 Manufacturer.
Daikin North America LLC................ Daikin.................... 13 Manufacturer.
Lennox International.................... Lennox.................... 8 Manufacturer.
Northwest Energy Efficiency Analysis.... NEEA...................... 14 Efficiency Advocacy
Organization.
New York State Energy Research and NYSERDA................... 6 State Official/Agency.
Development Authority.
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[[Page 63863]]

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 NOPR public meeting, DOE cites the written comments
throughout this final rule. DOE did not identify any oral comments
provided during the webinar 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 VRF multi-split systems. (Docket No. EERE-2021-
BT-TP-0019, which is maintained at <a href="http://www.regulations.gov">www.regulations.gov</a>). The
references are arranged as follows: (commenter name, comment docket
ID number, page of that document).
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On March 1, 2022, DOE published in the Federal Register an energy
conservation standards NOPR (``March 2022 VRF ECS NOPR'') that proposed
amended energy conservation standards for VRF multi-split systems that
rely on the new IEER cooling metric and are equivalent to the levels
specified in ASHRAE Standard 90.1-2019. 87 FR 11335.

II. Synopsis of the Final Rule

In this final rule, DOE is amending 10 CFR 431.96, ``Uniform test
method for the measurement of energy efficiency of commercial air
conditioners and heat pumps,'' to revise the relevant references to the
most recent version of the industry test procedure as follows: (1)
incorporating by reference AHRI 1230-2021 and ANSI/ASHRAE 37-2009, as
corrected by the Errata Sheet issued March 27, 2019; and (2)
establishing provisions for determining IEER for VRF multi-split
systems. DOE is also adding new appendices D and D1 to subpart F of
part 431, both titled ``Uniform test method for measuring the energy
consumption of variable refrigerant flow multi-split air conditioners
and heat pumps (other than air-cooled with rated cooling capacity less
than 65,000 Btu/h),'' (``appendix D'' and ``appendix D1,''
respectively). The current DOE test procedure for VRF multi-split
systems is relocated from 10 CFR 431.96 to 10 CFR part 431, subpart F,
appendix D without change, and the new test procedure adopting AHRI
1230-2021 is established in appendix D1 for determining IEER.
Compliance with appendix D1 is not required until such time as
compliance is required with amended energy conservation standards for
VRF multi-split systems that rely on IEER, should DOE adopt such
standards.
In this final rule, DOE is also updating its certification,
compliance, and enforcement (``CCE'') provisions for VRF multi-split
systems, to require reporting of information that is necessary for
testing VRF multi-split systems consistent with the updated industry
test procedure AHRI 1230-2021. Most significantly, these changes
include the incorporation of the controls verification procedure
(``CVP'') from AHRI 1230-2021 into DOE's product-specific enforcement
provisions at 10 CFR 429.134, as well as accompanying certification
requirements at 10 CFR 429.43. Additionally, DOE is specifying tested
combinations to align with AHRI 1230-2021, clarifying the role of
manufacturer involvement during testing, and specifying how to
determine represented values for systems using different indoor unit
combinations DOE is not reducing the enforcement testing sample size
from four units to two units, as was proposed in the December 2021 VRF
TP NOPR. Figure 1 presents a process diagram for DOE's certification,
compliance, and enforcement regulations for VRF multi-split systems, as
described in this final rule.
BILLING CODE 6450-01-P

[[Page 63864]]

[GRAPHIC] [TIFF OMITTED] TR20OC22.000

BILLING CODE 6450-01-C
The adopted amendments are summarized in Table II.1 and are
compared to the test procedure provisions in place prior to these
latest amendments, as well as the reason for each adopted change.

Table II-1--Summary of Changes in the Amended Test Procedure
------------------------------------------------------------------------
DOE test procedure prior to
amendment Amended test procedure Attribution
------------------------------------------------------------------------
Incorporates by reference ANSI/ Incorporates by Updates to the
AHRI 1230-2010. reference in a new applicable
Appendix D1 AHRI 1230- industry test
2021 and ANSI/ASHRAE procedures.
37-2009 as corrected
by the Errata Sheet
issued March 27, 2019.
Includes provisions for Includes provisions Updates to the
determining EER. for determining both applicable
EER and IEER. industry test
procedures.
Does not include VRF-specific Includes provisions in Establish VRF-
provisions for determination 10 CFR 429.43 specific
of represented values in 10 specific to VRF multi- provisions for
CFR 429.43. split systems to determination
determine represented of represented
values for models values.
with specific
components, and
determine represented
values for different
indoor unit
combinations.
Includes certification Adopts reporting Establish
requirements in 10 CFR 429.43 requirements reporting
consistent with testing to consistent with new requirements
EER per ANSI/AHRI 1230-2010. test requirements of consistent with
AHRI 1230-2021, updated
including tested industry test
combination, method.
certified critical
parameter values, and
instructions for
conducting the
controls verification
procedure (``CVP'').
Does not include VRF-specific Adopts product- Establish
enforcement provisions in 10 specific enforcement provisions for
CFR 429.134. provisions for VRF DOE testing of
multi-split systems VRF multi-split
including: systems.
verification of
cooling capacity,
testing of systems
with specific
components, break-in
period, manufacturer
involvement in
assessment or
enforcement testing,
provisions for when
DOE would conduct a
CVP, and how CVP
results would affect
critical parameters
used in IEER
enforcement testing
by DOE.
Does not provide VRF-specific Specifies VRF-specific Establish AEDM
instruction for validating AEDM validation instructions
alternative methods for criteria that are specific to VRF
determining energy efficiency dependent on indoor multi-split
and energy use (``AEDM'') at unit combinations systems.
10 CFR 429.70. offered by the
manufacturer.
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[[Page 63865]]

DOE has determined that the amendments described in section III of
this document regarding the establishment of appendix D do not alter
the measured efficiency of VRF multi-split systems or require retesting
solely as a result of DOE's adoption of the amendments to the test
procedure. DOE has determined that the amendments regarding the test
procedure in appendix D1 do alter the measured efficiency and are
consistent with the updated industry test procedure AHRI 1230-2021.
Further, use of the updated industry test procedure provisions and
amended representation requirements in 10 CFR 429.43 and 10 CFR 429.70
would not be required until the compliance date of any amended
standards based on IEER. Additionally, DOE has determined that the
finalized amendments will not increase the cost of testing relative to
the updated industry test procedure. The effective date for the amended
test procedures adopted in this final rule is 30 days after publication
of this document in the Federal Register. Discussion of DOE's actions
are addressed in detail in section III of this document.

III. Discussion

A. Scope of Applicability

This rulemaking applies to variable refrigerant flow multi-split
air conditioners and heat pumps. DOE defines variable refrigerant flow
multi-split air conditioners and heat pumps as units of commercial
package air conditioning and heating equipment that are configured as a
split system air conditioner or heat pump incorporating a single
refrigerant circuit, with one or more outdoor units, at least one
variable-speed compressor or an alternate compressor combination for
varying the capacity of the system by three or more steps, and multiple
indoor fan coil units, each of which is individually metered and
individually controlled by an integral control device and common
communications network and which can operate independently in response
to multiple indoor thermostats. 10 CFR 431.92. Variable refrigerant
flow implies three or more steps of capacity control on common, inter-
connecting piping. Id. VRF multi-split heat pumps use reverse cycle
refrigeration as its primary heating source and may include second
supplemental heating by means of electrical resistance, steam, hot
water, or gas. Id.
DOE is not amending the scope of the Federal test procedure for VRF
multi-split systems. DOE's current test procedure regulations for
commercial air conditioners and heat pumps at 10 CFR 431.96 include
test procedures that apply to air-cooled VRF multi-split air
conditioners, air-cooled VRF multi-split heat pumps, and water-source
VRF multi-split heat pumps,\8\ all with cooling capacity less than
760,000 Btu/h. Table 1 of 10 CFR 431.96. Single-phase, air-cooled VRF
multi-split air conditioners and heat pumps with cooling capacity less
than 65,000 Btu/h are subject to DOE's consumer product regulations for
central air conditioners, and test procedures for these products are
specified in appendices M and M1 to subpart B of part 430. Test
procedures for three-phase, air-cooled VRF multi-split systems with
cooling capacity less than 65,000 Btu/h are not addressed in this final
rule and are instead addressed in a separate test procedure rulemaking
for air-cooled, three-phase, small commercial package air conditioning
and heating equipment with a cooling capacity of less than 65,000 Btu/h
(see Docket No. EERE-2017-BT-TP-0031).
---------------------------------------------------------------------------

\8\ The EPCA definition for ``commercial package air
conditioning and heating equipment'' specifically excludes ground
water source equipment. (42 U.S.C. 6311(8)(A)).
---------------------------------------------------------------------------

B. Organization of the VRF Multi-Split System Test Procedure

In the December 2021 VRF TP NOPR, DOE proposed to relocate and
centralize the current test procedure for VRF multi-split systems to a
new appendix D to subpart F of part 431, such that appendix D would not
amend the current test procedure. 86 FR 70644, 70649 (Dec. 10, 2021).
The proposed appendix D would also centralize the additional test
provisions currently applicable under 10 CFR 431.96 (i.e., optional
break-in period for tests conducted using ANSI/AHRI 1230-2010 (10 CFR
431.96(c)); refrigerant line length corrections for tests conducted
using ANSI/AHRI 1230-2010 (10 CFR 431.96(d); additional provisions for
equipment set-up (10 CFR 431.96(e); and manufacturer involvement in
assessment or enforcement testing for variable refrigerant flow systems
(10 CFR 431.96(f))). As proposed, VRF multi-split systems would be
required to be tested according to appendix D until such time as
compliance is required with an amended energy conservation standard
that relies on the IEER metric, should DOE adopt such a standard. Id.
Similarly, DOE proposed to amend the test procedure for VRF multi-
split systems by adopting AHRI 1230-2021 in a new appendix D1 to
subpart F of part 431. DOE proposed to adopt the updated version of
AHRI 1230, including the IEER metric. Id. As proposed, VRF multi-split
systems would not be required to be tested according to the test
procedure in proposed appendix D1 until such time as compliance is
required with an amended energy conservation standard that relies on
the IEER metric, should DOE adopt such a standard. Id.
DOE did not receive any comments in response to the proposed
organization of the test procedure. Accordingly, for the reasons
discussed in the December 2021 VRF TP NOPR and as discussed in the
preceding paragraphs, DOE is finalizing the proposed organization of
the test procedure by establishing appendices D and D1 for testing VRF
multi-split systems.

C. Industry Standards

1. Updates to AHRI 1230
As discussed in section I.B of this document, the VRF TP Term Sheet
recommended that DOE adopt the 2019 draft version of AHRI 1230 with
several changes, including:
<bullet> Adding a hierarchy of instructions for how to set up the
unit under test, and a clarification that ``as-shipped'' settings
should be used as a last resort when instructions are not provided in
the supplemental testing instructions (``STI'') and/or the
manufacturer's installation instructions (``MII'').
<bullet> Providing equations and example calculations of
adjustments to measured results for steady-state tests if sensible heat
ratio (``SHR'') \9\ limits are not met at the 100-percent full-load
and/or 75-percent part-load cooling test points.
---------------------------------------------------------------------------

\9\ Cooling load is composed of both sensible and latent
portions. The sensible load is the energy required to reduce the
temperature of the incoming air, without any phase change. The
latent load is the energy required to change the moisture in the air
from water vapor into a liquid phase as it condenses on the cooling
coil. Sensible heat ratio is a ratio of the sensible cooling
capacity to the total cooling capacity at a given test condition.
---------------------------------------------------------------------------

<bullet> Amending the definition of the draft CVP to include a
definition of time periods for determining critical parameter
validation and allowable critical parameter tolerances using
manufacturer-provided data. (Docket No. EERE-2018-BT-STD-0003-0044 at
p. 2)
After the VRF ASRAC Working Group meetings in 2019, DOE provided
technical support in an AHRI 1230 Technical Committee to address the
three outstanding items identified in the VRF TP Term Sheet. For the
last item--determining critical parameter tolerances--DOE compiled
anonymized, aggregated test data to share with the committee. In a
presentation to the AHRI 1230 Technical Committee on September 10,
2020, DOE shared data

[[Page 63866]]

on the variability of critical parameter results as measured during
different CVP runs, as well as data on how the measured IEER changed in
response to changes in critical parameters. (EERE-2018-BT-STD-0003-
0063) DOE presented options that could be considered to express the
maximum allowable variation in critical parameters as a ``budget.'' The
AHRI 1230 Technical Committee incorporated a budget of 70 points (a
measure of critical parameter variation) in the draft AHRI 1230, which
is outlined in section III.E.1 of this document.
Following the completion of the AHRI 1230 Technical Committee
meetings, in May 2021, AHRI published AHRI 1230-2021, which
incorporated the changes consistent with those recommended in the VRF
TP Term Sheet. The following list includes substantive changes in AHRI
1230-2021 as compared to ANSI/AHRI 1230-2010, the version currently
used for certification:
<bullet> Air-cooled VRF multi-split systems with cooling capacity
less than 65,000 Btu/h were removed from the scope of the industry test
standard. These systems are addressed by AHRI 210/240-2023,
``Performance Rating of Unitary Air-conditioning & Air-source Heat Pump
Equipment.''
<bullet> Maximum SHR limits of 0.82 and 0.85 were added for full-
load and 75-percent part-load conditions, respectively.
<bullet> A CVP was added that verifies that the values certified in
the STI for setting critical parameters during steady-state testing are
within the range of critical parameters that would be used by the
system's native controls at the same conditions. A 70-point budget was
also added as the criteria for critical parameter validation during the
CVP.
<bullet> A hierarchy was added indicating which sources of
manufacturer's instructions to use during testing in the case of
conflicting information among different sources.
<bullet> Provisions were updated for refrigerant piping length
requirements and for the correction factors applied in the case of
excess refrigerant piping length used during testing.
<bullet> For water-source equipment, the maximum water flow rate
was reduced and part-load entering water temperatures were modified.
<bullet> New provisions were added to specify test methods and
conditions for cases in which condenser head pressure controls result
in unstable operation in part-load cooling tests.
<bullet> The provisions for tested combinations, which specify the
indoor unit combination to be used for testing, were updated to replace
``highest sales volume'' requirements with a specific hierarchy based
on ``indoor unit model family'' (e.g., wall-mounted, compact 4-way
ceiling cassette, mid-static ducted).
<bullet> A maximum airflow rate of 55 standard cubic feet per
minute (``scfm'') per 1,000 Btu/h was added for non-ducted indoor
units, and the maximum airflow rate was increased for ducted indoor
units from 37.5 scfm per 1,000 Btu/h to 42 scfm per 1,000 Btu/h.
<bullet> Test tolerances for indoor air entering wet-bulb
temperatures were increased. Specifically, the indoor wet-bulb
temperature operating tolerance was increased from 1 [deg]F to 1.8
[deg]F. The indoor wet-bulb temperature condition tolerance was also
increased from 0.30 [deg]F to 0.36 [deg]F. Additionally, the operating
tolerance for external static pressure (``ESP'') for ducted units was
changed from 0.05 in H<INF>2</INF>O to 10 percent of the ESP reading.
<bullet> Appendix D to ANSI/AHRI 1230-2010 with Addendum 1, ``Test
Requirements,'' was amended in ANSI/AHRI 1230-2021 and redesignated as
Appendix E, ``ANSI/ASHRAE Standard 37-2009 Clarifications/Exceptions.''
This appendix provides additional instruction and exceptions to the use
of ANSI/ASHRAE 37-2009.
<bullet> Informative appendices were added that show example
calculations for IEER and the CVP ``budget'' method, which calculates
the variation between measured critical parameter values and STI-
reported critical parameter values.
As part of the December 2021 VRF TP NOPR, DOE evaluated the extent
to which a test procedure based on AHRI 1230-2021 would meet the EPCA
requirements to produce test results that reflect the energy
efficiency, energy use, and estimated operating costs of that equipment
during a representative average use cycle, and for such test procedure
to not be unduly burdensome to conduct. DOE tentatively concluded that
the changes in AHRI 1230-2021 better reflect the field performance of
VRF multi-split systems and provide additional clarification for
testing provisions. 86 FR 70644, 70650, 70669 (Dec. 10, 2021). DOE also
tentatively determined that a test procedure based on AHRI 1230-2021
would not be unduly burdensome to conduct. 86 FR 70644, 70669 (Dec. 10,
2021).
Therefore, DOE proposed to adopt the updated version of AHRI 1230,
including the IEER metric, and to incorporate by reference AHRI 1230-
2021 in a new appendix D1 to subpart F of part 431. 86 FR 70644, 70650
(Dec. 10, 2021). DOE proposed to reference the following sections from
AHRI 1230-2021: Section 3 (except 3.11),\10\ Section 5 (except 5.1.2),
Section 6 (except 6.3.3 and 6.5), Section 11, Section 12, and Appendix
E. 86 FR 70644, 70650-70651 (Dec. 10, 2021). The remaining sections
were excluded as either: (1) informative appendices not needed in the
DOE test procedure; (2) procedures specific to the AHRI verification
program that are not warranted for a DOE test procedure, or (3)
sections for which DOE proposed modifications. Id.
---------------------------------------------------------------------------

\10\ The CA IOUs stated that in proposed updates to 10 CFR
431.97, subpart F, appendix D1, DOE states that critical
parameter(s) are defined in section 3.10 of AHRI 1230-2021, but the
correct reference should be to section 3.11 of that industry
standard. (CA IOUs, No. 11 at p. 4) DOE acknowledges this
typographical error and has corrected the section references in this
final rule.
---------------------------------------------------------------------------

In the December 2021 VRF TP NOPR, DOE included discussion on
several test method topics about which DOE requested comment in the
July 2017 ASHRAE TP RFI and received stakeholder comments in response
to that RFI. These topics included setting indoor airflow and external
static pressure, condenser head pressure controls, indoor unit
operation during part-load tests, oil recovery mode during transient
testing, secondary methods for capacity measurement, and heat recovery.
All of these test method topics were addressed in AHRI 1230-2021, and
DOE did not propose any deviations from AHRI 1230-2021 on any of the
topics. 86 FR 70644, 70653-70656 (Dec. 10, 2021). DOE did not receive
any comments regarding these test method topics in response to the
December 2021 VRF TP NOPR, but as discussed, the Department did receive
comments generally supportive of DOE's proposal to adopt AHRI 1230-
2021. Along these lines, Carrier, Lennox, the CA IOUs, AHRI, Daikin,
and NEEA all commented that they support DOE's proposal to adopt AHRI
1230-2021. (Carrier, No. 7 at p. 1; Lennox, No. 8 at pp. 1-2; CA IOUs,
No. 11 at p. 3; AHRI, No. 12 at p. 2; Daikin, No. 13 at p. 2; NEEA, No.
14 at p. 2) NEEA further commented that AHRI 1230-2021 adds clarifying
provisions that will reduce variability in results. (NEEA, No. 14 at p.
2)
For the reasons discussed in the December 2021 VRF TP NOPR and
consistent with the comments received in support of DOE adopting AHRI
1230-2021, DOE concludes that as compared to previous versions of AHRI
1230 (including ANSI/AHRI 1230-2010 which is referenced in the current
Federal test procedure), AHRI 1230-2021 generally provides results that
are more representative of an average use cycle for VRF multi-split
systems, provides additional clarification for

[[Page 63867]]

testing provisions, and is not unduly burdensome to conduct. In
particular, DOE finds that AHRI 1230-2021 includes several test
procedure amendments that better reflect typical operation and
performance of VRF indoor units, including the addition of SHR limits,
further specification of indoor airflow, and changes to indoor unit
tested combinations. DOE also finds that the addition of the CVP in
AHRI 1230-2021 (which DOE is adopting in enforcement provisions) will
improve representativeness by more closely tying controls behavior
during testing to controls behavior that would be expected to occur in
a field installation under native controls. Therefore, in this final
rule DOE is incorporating by reference AHRI 1230-2021 and adopting
specific sections for testing VRF multi-split systems as proposed.
Sections of AHRI 1230-2021 for which DOE is adopting modifications are
discussed in following sections of this final rule.
2. ASHRAE 37
ANSI/ASHRAE Standard 37, which provides a method of test for many
categories of air conditioning and heating equipment, is referenced for
testing VRF multi-split systems by ANSI/AHRI 1230-2010, ANSI/AHRI 1230-
2014 with Addendum 1, and AHRI 1230-2021. ANSI/ASHRAE 37-2005 is
referenced in ANSI/AHRI 1230-2010, which is the currently referenced
industry test standard in the DOE test procedure for VRF multi-split
systems.\11\ ANSI/ASHRAE 37-2009 is referenced in ANSI/AHRI 1230-2014
with Addendum 1 and AHRI 1230-2021. To reflect the use of ANSI/ASHRAE
37-2009 in conducting testing according to AHRI 1230-2021, DOE proposed
in the December 2021 VRF TP NOPR to incorporate by reference ANSI/
ASHRAE 37-2009 (except for sections 1, 2, and 4) including the errata
sheet issued March 27, 2019 (which corrected the total heating capacity
equations for the outdoor liquid coil method in section 7.6.5.1 of that
test standard) \12\ in the proposed appendix D1 for the VRF multi-split
systems test procedure. 86 FR 70644, 70651 (Dec. 10, 2021). DOE did not
receive any comments in response to its proposal to reference ASHRAE
37-2009 in the test method for VRF multi-split systems. Accordingly,
DOE concludes that ASHRAE 37-2009 is an integral component of testing
VRF multi-split systems (per the 2014 and 2021 versions of AHRI 1230)
and that it ensures representativeness and repeatability of the test
procedure by specifying instrumentation requirements, test set-up
provisions, calculation methods, and test tolerances. Therefore, DOE
incorporates by reference ANSI/ASHRAE 37-2009 (as corrected by the most
recent errata sheet issued March 27, 2019) and adopts the relevant
sections for testing VRF multi-split systems, as proposed.
---------------------------------------------------------------------------

\11\ In the December 2021 VRF TP NOPR, DOE incorrectly stated
that ANSI/AHRI 1230-2010 references ANSI/ASHRAE 37-2009. 86 FR
70644, 70651 (Dec. 10, 2021).
\12\ The errata sheet, which was updated on March 27, 2019, is
available at: <a href="http://www.ashrae.org/file%20library/technical%20resources/standards%20and%20guidelines/standards%20errata/standards/37-2009errata-3-27-2019-.pdf">www.ashrae.org/file%20library/technical%20resources/standards%20and%20guidelines/standards%20errata/standards/37-2009errata-3-27-2019-.pdf</a> (Last accessed Sept. 7, 2022).
---------------------------------------------------------------------------

D. Metrics

1. IEER
In the December 2021 VRF TP NOPR, DOE provided considerable
background on the IEER metric, and the Department proposed to adopt the
IEER metric and the relevant provisions in AHRI 1230-2021 to determine
IEER for VRF multi-split systems. DOE currently prescribes energy
conservation standards for air-cooled VRF multi-split systems with
cooling capacity greater than or equal to 65,000 Btu/h and water-source
VRF multi-split heat pumps in terms of the EER metric for cooling-mode
operation and in terms of the COP metric for heating-mode operation.
EER and COP capture the system performance at single, full-load
operating points in cooling and heating mode, respectively (i.e.,
single outdoor air temperatures for air-cooled systems and single
entering water temperatures for water-source systems). Neither metric
provides a seasonal or load-weighted measure of energy efficiency. 86
FR 70644, 70651 (Dec. 10, 2021).
In contrast, the IEER metric factors in the efficiency of operating
at full-load conditions as well as part-load conditions of 75-percent,
50-percent, and 25-percent of full-load capacity. In general, the IEER
metric provides a more representative measure of field performance by
weighting the full-load and part-load efficiencies by the average
amount of time equipment spends operating at each load. Id.
IEER was first specified in a 2008 supplement to ASHRAE Standard
90.1-2007 for commercial air-cooled, water-cooled, and evaporatively-
cooled air conditioning and heat pump equipment. ASHRAE Standard 90.1-
2010 included minimum efficiency levels in terms of both EER and IEER
for air-cooled VRF multi-split systems. ASHRAE Standard 90.1-2016 added
IEER levels for water-source VRF multi-split heat pump systems,
including systems with cooling capacity less than 65,000 Btu/h, in
addition to the specified EER levels. On January 15, 2016, DOE
published a direct final rule in the Federal Register for energy
conservation standards for air-cooled commercial unitary air
conditioners (air-cooled CUACs, or ACUACs), which amended the energy
conservation standards for ACUACs and changed the cooling efficiency
metric from EER to IEER, with compliance required starting January 1,
2018. 81 FR 2420.
The proposal to adopt the IEER metric and relevant provisions of
AHRI 1230-2021 in the test procedure for VRF multi-split systems
aligned with the VRF TP Term Sheet upon which the ASRAC Working Group
agreed. 86 FR 70644, 70652 (Dec. 10, 2021). DOE also proposed to amend
the definition for IEER at 10 CFR 431.92 to distinguish between the
test procedures for ACUACs and VRF multi-split systems. Id.
Lennox, the CA IOUs, AHRI, Daikin, and NEEA commented that they
support DOE's proposal to adopt the IEER metric for VRF multi-split
systems. (Lennox, No. 8 at pp. 1-2; CA IOUs, No. 11 at p. 3; AHRI, No.
12 at p. 2; Daikin, No. 13 at p. 2; NEEA, No. 14 at p. 2) Lennox and
NEEA stated that IEER improves the representativeness of the tested
value for VRF multi-split systems. (Lennox, No. 8 at p. 2; NEEA, No. 14
at p. 2) The CA IOUs and NEEA commented that IEER informs consumers of
the part-load performance benefits of variable speed equipment. (CA
IOUs, No. 11 at p. 3; NEEA, No. 14 at p. 2) AHRI, Daikin, and Lennox
supported DOE's proposed revision to the definition of IEER to
differentiate between the test procedures for ACUAC and VRF multi-split
systems. (AHRI, No. 12 at p. 2; Daikin, No. 13 at p. 2; Lennox, No. 8
at p. 2)
NEEA commented that DOE should investigate the differences between
AHRI 1230-2021 and ANSI/AHRI 1230-2010, because manufacturers currently
certify IEER measured per 1230-2010 for the AHRI certification program.
The commenter stated that testing according to the new version of AHRI
1230 could result in different IEER values, which could cause market
confusion, so NEEA suggested that DOE consider changing the name of the
metric measured per AHRI 1230-2021 to ``IEER2.'' (NEEA, No. 14 at p. 2)
Regarding NEEA's comment, the changes in AHRI 1230-2021 as compared
to ANSI/AHRI 1230-2010 better reflect typical operation and performance
of VRF multi-split systems (see section III.C.1 of this document for
further discussion). In particular, DOE

[[Page 63868]]

finds that AHRI 1230-2021 includes several test procedure amendments
that better reflect typical operation and performance of VRF indoor
units, including the addition of SHR limits, further specification of
indoor airflow, and changes to indoor unit tested combinations. DOE
also finds that the addition of the CVP in AHRI 1230-2021 (which DOE is
adopting in enforcement provisions) will improve representativeness by
more closely tying controls behavior during testing to native controls
behavior that would be expected to occur in a field installation. DOE
also notes that the VRF TP Term Sheet included as Recommendation #1
that VRF multi-split systems should be rated with the IEER metric.
(Docket No. EERE-2018-BT-STD-0003-0044) This recommendation was
unanimously agreed upon by all Working Group members, as it allowed for
comparisons to CUAC ratings, which also use the IEER efficiency metric.
Further, DOE does not require certification of IEER as measured per
ANSI/AHRI 1230-2010 nor does it include IEER in its current test
procedure for VRF multi-split systems. Therefore, DOE concludes that
there is not a need to deviate from the metric name ``IEER'' specified
in AHRI 1230-2021 and that doing so might spawn unnecessary confusion
by suggesting that there is some significant difference as to how that
term is used in the context of the amended Federal test procedure as
compared to AHRI 1230-2021. Consequently, DOE is adopting the IEER
metric measured per AHRI 1230-2021 in the Federal test procedure for
VRF multi-split systems, as proposed. Further, DOE is adopting the
proposed revisions to the definition for IEER at 10 CFR 431.92 to
distinguish between the test procedures for ACUACs and VRF multi-split
systems.
2. Test Conditions Used for Efficiency Metrics
AHRI 1230-2021 includes a number of test conditions used to
determine rated performance of VRF multi-split systems in both cooling
mode and heating mode. Standard rating tests in cooling mode include
the full-load cooling and three part-load cooling tests used to
determine IEER. Standard rating tests in heating mode differ depending
on whether the VRF multi-split heat pump is water-source or air-source.
For water-source systems, there is only one heating mode standard
rating test. For air-source systems, there are two heating mode
standard rating tests (one at 47 [deg]F outdoor temperature and another
at 17 [deg]F outdoor temperature).
In the December 2021 VRF TP NOPR, DOE proposed to specify in the
test procedure for VRF multi-split systems which test conditions would
be required for compliance with standards, were DOE to amend the energy
conservation standards based on AHRI 1230-2021, and to specify
additional test conditions that would be included in the DOE test
procedure for making optional representations of efficiency. 86 FR
70644, 70652-70653 (Dec. 10, 2021). Specifically, for air-cooled VRF
multi-split systems, DOE proposed to specify in section 3.1 of the
proposed appendix D1 that the cooling test conditions used for
compliance would be the ``Standard Rating Conditions, Cooling'' and
``Standard Rating Part-Load Conditions (IEER)'' conditions specified in
Table 8 \13\ of AHRI 1230-2021. DOE also proposed to specify in section
4.1 of the proposed appendix D1 that the heating test condition used
for compliance would be the ``Standard Rating Conditions, High
Temperature Steady-State Test for Heating'' conditions (47 [deg]F)
specified in Table 8 of AHRI 1230-2021. DOE also proposed to specify in
section 4.1.1 of the proposed appendix D1 that representations of COP
would be optional for the ``Low Temperature Steady-state Test for
Heating'' conditions (17 [deg]F), also specified in Table 8 of AHRI
1230-2021. For water-source VRF multi-split heat pumps, DOE proposed to
specify in section 3.2 of the proposed appendix D1 that the test
conditions used for compliance would be the standard rating test
conditions for ``Water Loop Heat Pumps'' and proposed in section 4.2.1
of proposed appendix D1 that representations of EER and COP at the
standard rating conditions for ``Ground-loop Heat Pumps'' would be
optional. Id.
---------------------------------------------------------------------------

\13\ AHRI commented in response to the December 2021 NOPR that
DOE incorrectly identified the relevant table numbers of AHRI 1230-
2021. They clarified that Table 8 of AHRI 1230-2021 outlines
``standard rating conditions'' for air-source VRF multi-split
systems, while Tables 9 and 10 provide these conditions for water-
source VRF multi-split systems for cooling mode and heating mode,
respectively. (AHRI, No. 12 at p. 10) DOE has corrected these
references in this final rule.
---------------------------------------------------------------------------

In response to DOE's proposed rating conditions, NYSERDA encouraged
DOE to work with industry stakeholders to improve the
representativeness of heating-mode performance ratings by: (1) adding
rating points at colder ambient temperatures and (2) encouraging DOE to
shift from regulating based on a single test point to an integrated
heating metric. NYSERDA asserted that the VRF heating performance
rating (COP at 47 [deg]F) does not provide customers with sufficient
information to determine equipment performance at temperatures
experienced by New Yorkers during much of the winter season.
Specifically, the commenter advocated that a rating condition at colder
temperatures such as 5 [deg]F or 0 [deg]F is needed to provide colder
climates with the data necessary to determine which VRF equipment is
most appropriate. NYSERDA also encouraged DOE to change the test
condition used for determining heating capacity from 47 [deg]F to 17
[deg]F (or lower). Regarding an integrated heating metric, NYSERDA
commented that although integrated ratings are not reflective of any
specific building type or climate zone, they provide a relative ranking
of products, thereby allowing consumers to understand which models are
likely to perform better than others across a range of ambient
temperatures and load levels on the equipment. NYSERDA commented that
an integrated heating metric for VRFs would be more representative than
COP at 47 [deg]F. (NYSERDA, No. 6 at p. 2) Furthermore, NYSERDA
requested that if its comments could not be addressed in the current
rulemaking, then it asked DOE to consider its comments for the next
update of VRF test procedures. (NYSERDA, No. 6 at p. 3) No other
comments were received as to the proposed test conditions for VRF
multi-split systems.
In response, DOE notes that for VRF multi-split systems, the
generally accepted industry test procedure is AHRI 1230-2021, which for
air-source heat pumps only includes provisions to determine the COP
rating at a high temperature point of 47 [deg]F and at a low
temperature point of 17 [deg]F (outdoor air dry-bulb temperatures).
Neither AHRI 1230-2021 nor previous versions of AHRI 1230 include the
provisions needed to determine heating performance at other outdoor
temperatures or specify an integrated metric for heating.
Regarding the addition of heating conditions at temperatures colder
than 17 [deg]F or adoption of an integrated heating metric (which as
described by NYSERDA, would involve adding part-load heating tests), at
this time, DOE lacks sufficient evidence to adopt tests for VRF multi-
split systems at conditions other than those specified in the updated
industry consensus test procedure, AHRI 1230-2021. Further, DOE does
not have data as to representative test conditions, load levels, and
weighting factors to be included in an integrated heating metric for
VRF multi-split systems.
Regarding the suggestion that rated heating capacity be based on
performance at 17 [deg]F instead of 47 [deg]F,

[[Page 63869]]

NYSERDA did not provide evidence that heating capacity measured at 17
[deg]F would be more representative for VRF multi-split systems for the
nation as a whole. Further, all other commercial heat pump equipment
categories regulated by DOE also have the rated heating capacity
measured at 47 [deg]F, thus allowing comparison at the same condition
across equipment categories. Additionally, the AHRI Directory of
Certified Product Performance \14\ includes heating capacity measured
at both 47 [deg]F and 17 [deg]F; therefore, to the extent stakeholders
are interested in heating capacity of VRF multi-split systems at 17
[deg]F, they can obtain such information from the data made publicly
available in the AHRI Directory for systems included in AHRI's
certification program.
---------------------------------------------------------------------------

\14\ The AHRI directory for VRF multi-split systems is available
at: <a href="http://www.ahridirectory.org/NewSearch?programId=72&searchTypeId=3">www.ahridirectory.org/NewSearch?programId=72&searchTypeId=3</a>
(Last accessed July 8, 2022).
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DOE notes that NYSERDA acknowledged that the Department is
finalizing its test procedure rulemaking for VRF multi-split systems
and that the commenter's suggestions may not be able to be incorporated
in this rulemaking. Absent data supporting the representativeness of
alternate test conditions and an alternate metric, as well as a lack of
information as to which test conditions would be included in a
representative integrated heating metric, DOE is not considering test
conditions or metrics for VRF multi-split systems other than those
proposed in the December 2021 VRF TP NOPR. Therefore, DOE is not
adopting a lower-temperature heating test or an integrated heating
metric for VRF multi-split systems, as recommended by NYSERDA. For the
reasons discussed in the December 2021 VRF TP NOPR and in the preceding
paragraphs, DOE is finalizing its proposals from the December 2021 VRF
TP NOPR regarding test conditions for VRF multi-split systems.

E. Controls Verification Procedure

Section 5.1.2.1 of AHRI 1230-2021 specifies that during steady-
state performance rating tests for cooling and heating efficiency, VRF
multi-split systems must operate under commands from system controls
except for certain components, referred to as ``critical parameters,''
which are allowed to be set by a manufacturer's representative. These
critical parameters are (1) compressor speed(s), (2) outdoor fan
speed(s), and (3) outdoor variable valve positions. Settings for
critical parameters are allowed to be manually controlled using a
manufacturer control tool, as opposed to all other components which
must operate per commands from the system controls. The measured
performance of VRF multi-split systems depends, in part, on the
operating positions of each of these critical parameters. Accordingly,
Section 5.1.2 of AHRI 1230-2021 states that operational settings for
each of the critical parameters must be specified in the STI, and that
each of the critical parameters must be allowed to be manually adjusted
(to match the STI-certified values) during testing.
AHRI 1230-2021 also includes a normative Appendix C that specifies
a CVP. The purpose of the CVP is to validate that the observed
positions of critical parameters during the CVP are within tolerance of
the STI-certified critical parameter values that are set by the
manufacturer in steady-state IEER cooling tests (see section III.E.4 of
this final rule for discussion of CVP results). This ensures that the
measured results of the IEER test procedure are based on critical
parameter settings that are representative of critical parameter
behavior that would be experienced in the field. The December 2021 VRF
TP NOPR includes additional information about the CVP. See 86 FR 70644,
70658-70663 (Dec. 10, 2021).
1. Background
DOE's current test procedure for VRF multi-split systems includes
allowances in 10 CFR 431.96(f) for limited manufacturer involvement in
assessment or enforcement testing. A manufacturer's representative may
adjust components such as the compressor speed, fan speeds, and valve
positions for the purposes of achieving steady-state conditions during
testing. 10 CFR 431.96(f). This adjustment process is provided for VRF
multi-split systems because of the complexity of VRF multi-split
systems and the variety of settings needed to perform a test. 77 FR
28928, 28946 (May 16, 2012). DOE's current certification requirements
for VRF multi-split systems, found at 10 CFR 429.43(b)(4), specify that
the STI must include compressor frequency setpoints and required dip
switch/control settings for step or variable components. However, DOE's
current regulations do not require these settings to match system
behavior when the VRF multi-split system is operating under its own
controls. Further, there are no constraints regarding the allowable
range of adjustments that a manufacturer's representative may make to
reach steady-state operation.
In October 2018, during the negotiation meetings of the Working
Group, the CA IOUs raised concern (supported by field and laboratory
test data) as to the representativeness of the ANSI/AHRI 1230-2010
method, particularly with respect to control inputs used at part-load
test conditions. (Docket Nos. EERE-2018-BT-STD-0003-0011 and EERE-2018-
BT-STD-0003-0013) Ultimately, the VRF TP Term Sheet from the Working
Group recommended that DOE adopt an updated draft of AHRI 1230 that
included a controls verification procedure as an appendix. (Docket No.
EERE-2018-BT-STD-0003-0044 at pp. 1-2)
Appendix C of AHRI 1230-2021 establishes a CVP.\15\ The CVP
verifies whether critical parameter settings certified in the STI,
implemented by the manufacturer's representative during full-load and
part-load steady-state cooling tests for IEER, are within the range of
settings that would be used by the system during operation in the
field--the system's native controls. The behavior of each critical
parameter is monitored and recorded throughout the duration of a CVP.
In contrast to steady-state tests in which test conditions are held
constant, the CVP is a dynamic cooling test method in which certain
test conditions are intentionally varied throughout the test.
Specifically, the indoor room dry-bulb temperature is steadily
decreased during the CVP using the room conditioning apparatus, in
order to determine how the VRF multi-split system under test responds
to approaching and achieving its setpoint. Outdoor room test conditions
are held constant during the CVP. The CVP may be conducted at any of
the four IEER outdoor air or entering water temperature conditions. At
the start of the CVP, the indoor room test chamber temperature is
controlled to a manufacturer-specified value that must be between 82
[deg]F and 86 [deg]F, and the VRF indoor units are set to control to a
constant indoor temperature, 80 [deg]F, except as explained by Section
5.1.5 of AHRI 1230-2021. Section 5.1.5 provides instructions for
adjusting the VRF indoor unit setpoints (deviating from 80 [deg]F) to
account for setpoint bias and setpoint offset.\16\ VRF indoor units

[[Page 63870]]

typically use the calculated temperature difference between the
setpoint and the measured indoor air temperature as a control parameter
for determining when to shut down and become thermally inactive.
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\15\ The concept for the CVP originated from a minimum
compressor speed verification procedure provided in Japanese
standard JIS B 8616:2006, Package Air Conditioners, which is
included as an informative reference in appendix B of AHRI 1230-
2021, but not directly referenced within AHRI 1230-2021. Available
at <a href="http://www.jsajis.org/index.php?main_page=product_info&cPath=2&products_id=13290">www.jsajis.org/index.php?main_page=product_info&cPath=2&products_id=13290</a>.
\16\ AHRI 1230-2021 provides the following definitions for these
terms in sections 3.29 and 3.30, respectively:
Setpoint Bias--The difference between 80 [deg]F and the nominal
thermostat setpoint required for the thermostat to control for 80
[deg]F sensed temperature at the sensed location.
Setpoint Offset--The difference between the temperature
indicated by a thermostat's temperature sensor and the actual
temperature at the sensor's location.
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As discussed, the timing of the first indoor unit becoming
thermally inactive dictates the allowable time period for determining
whether certified critical parameter values have been validated, so it
is crucial to account for setpoint bias and offset to ensure repeatable
test results. After setting initial indoor air temperature, including
any adjustments to control for setpoint bias and offset, the CVP
proceeds by incrementally decreasing the indoor room test chamber
temperature while the VRF multi-split system setpoint is held constant.
As the indoor room temperature approaches and eventually passes below
the VRF multi-split system setpoint, the VRF multi-split system
controls should begin to register that the cooling demand has been
satisfied, and the system will begin to ``unload,'' meaning reduce
capacity.\17\ VRF multi-split systems typically unload by modulating
component settings, including critical parameters, from the values used
when providing full-load cooling capacity.
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\17\ Figure C.1 in AHRI 1230-2021 displays an example schematic
of the indoor dry-bulb temperature in [deg]F, compressor speed in
Hz, and the number of thermally active indoor units over the
duration of a CVP test.
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During this unloading period and up until the time that the first
indoor unit becomes thermally inactive, critical parameters are
compared against the critical parameter values that are certified in
the STI. Once the first indoor unit becomes thermally inactive, the
indoor room dry-bulb temperature continues decreasing until the indoor
room reaches 77 [deg]F. Section C6 of AHRI 1230-2021 includes equations
for determining ``RSS Points Total'' \18\--an aggregated and normalized
measure of deviation of all critical parameters from their certified
values--and also includes criteria for determining whether or not the
CVP has validated the certified critical parameter settings. The
verification criteria specified in Section C6 of AHRI 1230-2021 for
critical parameters measured during the CVP constitute a ``budget
method'' that applies a limit to the calculated RSS Points Total across
all three critical parameters instead of applying individual tolerances
to each individual critical parameter.\19\ This method allows
manufacturers flexibility in critical parameter control strategies
while still constraining the overall variation in VRF multi-split
system performance. The budget method can be applied the same way
regardless of the number of critical parameters that a manufacturer
certifies to their STI. For any critical parameter whose value is not
certified in the STI, (i.e., not designated as being controlled during
the IEER cooling tests), the deviation in that parameter will be
calculated as zero for the duration of the CVP. Section C6.1.2 of AHRI
1230-2021 specifies that the certified critical parameters are valid if
at least one measurement period of at least three minutes and a minimum
of five sample readings exists where the average RSS Points Total is
less than or equal to 70 points. Section C6.1.3 specifies the converse,
i.e., if no such measurement period satisfying those critical
parameters exists within the CVP, then certified critical parameter
values are deemed invalid. As discussed and for the reasons explained
in the following sections, DOE is generally adopting the CVP provisions
as proposed in the December 2021 VRF TP NOPR.
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\18\ In response to the December 2021 NOPR, the CA IOUs
commented that there were certain incorrect section references in
the December 2021 NOPR. They stated that proposed changes to 10 CFR
429.134(s)(3)(ii)(B) state that the RSS points total is defined in
Section 3.26 of AHRI 1230-2021, while the definition is actually in
section 3.27. (CA IOUs, No. 11 at p. 4). DOE has corrected the
section references in this final rule.
\19\ In addition to recommending inclusion of a CVP as an
appendix to the draft AHRI 1230, the VRF TP Term Sheet also
recommended that DOE determine appropriate values for critical
parameter tolerances using manufacturer-provided data. DOE
subsequently conducted testing and sensitivity analysis of several
VRF multi-split systems. The results were used to develop the
``budget method'' for CVP critical parameter verification specified
in Section C6 of AHRI 1230-2021.
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2. When the CVP Is Conducted
In the December 2021 VRF TP NOPR, DOE proposed to adopt the CVP
that is specified in appendix C of AHRI 1230-2021 in the product-
specific enforcement provisions for VRF multi-split systems at 10 CFR
429.134(s). 86 FR 70644, 70661 (Dec. 10, 2021). Additionally, DOE
proposed to specify at 10 CFR 429.134(s)(3) that DOE would conduct a
CVP at each of the four IEER cooling test conditions in the December
2021 VRF TP NOPR. Id. DOE also proposed to specify that the CVP would
be performed first at the full-load cooling condition to determine
maximum critical parameter values, before conducting the CVP at part-
load cooling conditions because the maximum critical parameter values
are used for calculating normalized deviation for CVPs at part-load
conditions. Id.
The CA IOUs, Daikin, and AHRI commented that they support DOE's
proposal to incorporate the CVP into its product-specific enforcement
provisions. (CA IOUs, No. 11 at p. 2; Daikin, No. 13 at p. 4; AHRI, No.
12 at p. 5) The CA IOUs stated that this proposal captured the intent
of the VRF TP Term Sheet and that this proposal will capture the
benefits of the CVP while limiting test burden primarily to the systems
included in enforcement testing. (CA IOUs, No. 11 at p. 2)
NEEA commented that the CVP is an essential process to verify that
the system can perform according to its rating. NEEA recommended that
the CVP should be required as a part of the test procedure, not only
included in enforcement provisions. The commenter stated that, without
performing a CVP as part of the test procedure, the manufacturer may
not be aware that its equipment is underperforming until DOE selects it
for enforcement testing. (NEEA, No. 14 at pp. 2-3)
Joint Advocates and the CA IOUs commented that they support DOE's
proposal to conduct a CVP at each of the four load points. The CA IOUs
stated that the CVP is important at part-load conditions, where
deviation in the VRF system performance is expected to be largest. (CA
IOUs, No. 11 at p. 2; Joint Advocates, No. 9 at p. 2) AHRI and Daikin
pointed out that DOE's proposal to conduct a CVP at each load point
would be more than what is required for AHRI's certification program.
(AHRI, No. 12 at p. 10; Daikin, No. 13 at p. 7) Daikin further
commented that, due to the relative newness of the CVP, manufacturers
would likely perform the same CVP tests that DOE would perform as part
of enforcement testing, thereby increasing test burden. (Daikin, No. 13
at p. 7) AHRI further commented that other than conducting the CVP at
all load points, the burdens of the NOPR proposals are similar to
current industry practice as indicated by AHRI 1230-2021. (AHRI, No. 12
at p. 10)
With regards to NEEA's comment, DOE did consider the potential
burden and benefits of including the CVP as part of the Federal test
procedure, and this evaluation revealed the following. To start, DOE
notes that the CVP is not required for rating models as part of the
industry consensus test procedure (AHRI 1230-2021). Per the
certification requirements adopted in this final rule (see section
III.G.2.b of this document), manufacturers will be required to report

[[Page 63871]]

the critical parameter settings at each of the IEER test conditions as
part of their STI. Consequently, DOE expects that manufacturers likely
will develop these certified values first through investigative testing
of some basic models and then later, as knowledge of VRF control
systems improves, through simulations. However, DOE expects that
manufacturers may determine that they do not need to conduct the CVP on
every basic model in order to understand the behavior of the system
controls to develop certified critical parameters. For instance, a
manufacturer may conduct a CVP on one or two models within a model line
and find that the resulting information provides an adequate basis to
develop certified critical parameters for other models in the model
line (e.g., similar models of differing capacities). Further,
manufacturers likely will have some understanding of the dynamic system
controls behavior of their models without conducting the CVP. Requiring
conducting the CVP for rating every basic model would not provide
manufacturers this discretion, and it could result in unnecessary and
costly testing.
Requiring the CVP to be conducted for every basic model would
require manufacturers to physically test every basic model of VRF
multi-split systems. Per current regulations at 10 CFR 429.43 and 10
CFR 429.70, manufacturers are allowed to rate VRF multi-split systems
using AEDMs and are not required to test every basic model. Therefore,
requiring the CVP to be conducted for every basic model would
substantially increase the number of basic models required to be
physically tested. Further, as described in the December 2021 VRF TP
NOPR, DOE estimated that the CVP would add approximately eight hours of
test time at each of the four IEER load conditions during enforcement
testing. 86 FR 70644, 70669 (Dec. 10, 2021). If the CVP were required
to be used at each IEER test condition, each basic model would
potentially require over 30 hours of testing time for the CVP, beyond
the testing time required to measure IEER.
Because manufacturers likely will conduct CVP testing and
simulation on a number of their VRF models in order to determine
representative certified settings for critical parameters in the STI
for all basic models, DOE finds that NEEA's suggestion to include the
CVP as part of the test procedure for VRF multi-split systems would not
substantially change the critical parameter settings manufacturers
would certify, and, thus, would not provide a significant increase in
representativeness of the test procedure. Further, NEEA's suggestion
would impose significantly more burden on manufacturers than the
approach proposed in the December 2021 VRF TP NOPR, because it would
require physical testing and conducting the CVP for every basic model,
rather than allowing manufacturers to decide the appropriate balance of
CVP testing and test burden to develop certified critical parameter
settings. Contrary to what NEEA suggests, DOE also finds it unlikely
that manufacturers would not take appropriate steps to assess their
equipment's performance under the CVP, particularly given the potential
business disruptions likely to result were underperformance to be
encountered for the first time in the context of DOE enforcement
testing. Given that not requiring the CVP for testing is consistent
with the VRF TP Term Sheet and the most recent industry consensus test
procedure, DOE does not have sufficient evidence to conclude that
requiring the CVP for testing would improve the representativeness of
the test procedure without being unduly burdensome. Therefore, DOE is
adopting the CVP as product-specific enforcement provisions for VRF
multi-split systems in 10 CFR 429.134(s) as proposed.
With regard to conducting the CVP at all four IEER load points, DOE
found through its investigative testing that there is substantial
variability in VRF system behavior observed at different IEER load
points, and that the system controls behavior at one IEER point does
not necessarily predict behavior at a different load point. Therefore,
DOE concludes that separately validating critical parameter behavior at
each IEER condition is needed as part of DOE enforcement testing in
order to sufficiently ensure representative system controls behavior.
In consideration of these factors and comments received, in this final
rule, DOE is adopting its proposals at 10 CFR 429.134(v)(3) regarding
performing a CVP at full-load cooling conditions first, then at each of
the part-load cooling conditions.
Adoption of the CVP in enforcement provisions will not require
manufacturers to conduct the CVP on every basic model. As previously
discussed, manufacturers likely will choose not to conduct the CVP for
every basic model of VRF multi-split systems, as they may find that
simulations, similarity between basic models (particularly between
models within a model line), and their understanding of the behavior of
their system controls provide sufficient basis to develop certified
critical parameter settings for some of their model offerings. To the
extent that manufacturers conduct CVP testing on their models in order
to sufficiently understand systems behavior, DOE acknowledges that its
adoption of CVP testing at all four IEER load points for enforcement
testing (rather than just at one IEER load point) may result in
manufacturers conducting the CVP at more IEER load conditions than they
otherwise would have. DOE acknowledges that in certain scenarios,
running three more CVPs could take up to 24 hours. However, by
performing the CVP at the same time as IEER testing, there would be no
additional test burden associated with unit set-up/commissioning.
Additionally, a CVP could be completed immediately following a steady-
state test run at the corresponding IEER load point, in which case
there would be no need to change the test chamber temperatures prior to
conducting the CVP. Therefore, DOE concludes that for the basic models
for which manufacturers choose to conduct the CVP, conducting the CVP
at all four IEER load points would not be unduly burdensome and would
increase the representativeness of the test procedure. As discussed,
DOE has concluded that conducting the CVP at all four IEER load points
is needed to ensure representative system behavior. Therefore, DOE is
adopting its proposals at 10 CFR 429.134(v)(3) that as part of
assessment or enforcement testing, DOE will perform a CVP at full-load
cooling conditions first, then at each of the part-load cooling
conditions.
In the December 2021 VRF TP NOPR, DOE also proposed to specify that
the CVP would be performed on a single system of the two-system sample
during enforcement testing. 86 FR 70644, 70661-70662 (Dec. 10, 2021).
AHRI, Lennox, the CA IOUs, and Daikin commented that performing a
CVP on a single system is adequate, provided that the testing
laboratory ensures the set-up is correct and that a manufacturer
representative is involved. (AHRI, No. 12 at p. 5; Lennox, No. 8 at p.
3; CA IOUs, No. 11 at p. 2; Daikin, No. 13 at p. 4)
For the reasons discussed in the December 2021 VRF TP NOPR and in
the preceding paragraphs, DOE adopts its proposal to perform the CVP on
a single system during assessment or enforcement testing. DOE is
clarifying in this final rule that a CVP would be performed on a single
system, regardless of the sample size used for enforcement (see section
III.G.7 of this document for further discussion of the enforcement
sampling plan). DOE's use of the CVP during assessment and enforcement

[[Page 63872]]

testing is illustrated in Figure 1 in section II of this final rule.
3. Critical Parameter Definition
In the December 2021 VRF TP NOPR, DOE proposed not to reference the
definition of ``critical parameters'' in Section 3.11 \20\ of AHRI
1230-2021 in order to be more explicit that the term ``critical
parameters'' refers only to those parameters specified by Section
5.1.2.1 of AHRI 1230-2021. DOE proposed to define critical parameters
in section 3 of appendix D1 as specifically referring to the following
settings of modulating components of VRF multi-split air conditioners
and heat pumps: compressor speed(s), outdoor fan speed(s) and outdoor
variable valve position(s). 86 FR 70644, 70659 (Dec. 10, 2021). DOE
tentatively concluded that the proposed change to the definition is
editorial in nature and would not change or conflict with any testing
provisions in AHRI 1230-2021. Id. at 86 FR 70659-70660.
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\20\ The CA IOUs stated that in proposed updates to 10 CFR
431.97, subpart F, appendix D1, DOE states that critical
parameter(s) are defined in section 3.10 of AHRI 1230-2021, but the
correct reference should be to section 3.11 of that industry
standard. (CA IOUs, No. 11 at p. 4) DOE acknowledges this
typographical error and has corrected the section references in this
final rule.
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AHRI and Daikin commented that the original definition for critical
parameters as written in AHRI 1230-2021 should be used in the DOE test
procedure. (AHRI, No. 12 at p. 3; Daikin, No. 13 at p. 2) AHRI stated
that Section 5.1.2.1 of AHRI 1230-2021 specifies what the critical
parameters are for a given system and stated their preference that this
be enumerated in the test requirements rather than the definition so as
to align with AHRI 1230-2021. (AHRI, No. 12 at p. 3) Daikin argued that
the proposed revision to the definition does not add more specificity
to which components can be adjusted. (Daikin, No. 13 at p. 2) The CA
IOUs commented that they support DOE's proposed definition for
``critical parameters'' and limiting the term to the parameters
specified in section 5.1.2.1 of AHRI 1230-2021, and they agreed with
DOE that the proposal would not conflict with any testing provisions in
AHRI 1230-2021. (CA IOUs, No. 11 at p. 4) Lennox commented that they
support DOE's proposal to clarify that critical parameters are limited
to compressor speeds, outdoor fan speeds, and outdoor variable valve
positions, stating that the proposed definition would provide clarity
and consistency when conducting a CVP. (Lennox, No. 8 at p. 3)
While section 5.1.2.1 of AHRI 1230-2021 clearly enumerates the
three types of components that can be specified for testing and
verified by conducting a CVP, the definition of ``critical parameter''
in AHRI 1230-2021 is rather vague, open-ended, and susceptible to a
reading that would permit inclusion of components that cannot be
overridden during testing (i.e., components other than compressor
speed(s), outdoor fan speed(s) and outdoor variable valve position(s)).
DOE concludes that specifying the relevant components in the definition
will add clarity to the test procedure without conflicting with
existing provisions or adding duplicative language into the test
procedure. Therefore, for the reasons discussed in the December 2021
VRF TP NOPR and in this paragraph, DOE is adopting its proposed
definition for critical parameters that specifically refers to the
relevant components: compressor speed(s), outdoor fan speed(s) and
outdoor variable valve position(s).
4. Validation of Certified Critical Parameters
As previously discussed, Sections C6.1.2 and C6.1.3 of AHRI 1230-
2021 specify validation criteria for the CVP using a budget method that
limits the calculated RSS Points Total across all three critical
parameters. In the December 2021 VRF TP NOPR, the Department discussed
this matter in some detail, and DOE tentatively determined that the
language in Sections C6.1.2 and C6.1.3 of AHRI 1230-2021 could be
construed and applied in multiple manners, and that this could lead to
differing test burdens. 86 FR 70644, 70660 (Dec. 10, 2021). The phrase
``a measurement period of at least three minutes and a minimum of five
sample readings'' could be misunderstood to indicate a measurement
period with no upper limit, potentially encompassing the entire
duration of the CVP. This reading could be misunderstood to require
iterative calculations of time periods of varying lengths when
validating critical parameters during the CVP (e.g., all three-minute
periods, and all four-minute periods, and all five-minute periods).
Taken to an extreme, this would result in thousands of calculations.
Further, the language ``where the average RSS Points Total is less than
or equal to 70 points'' does not indicate the specific procedure for
determining the average value of RSS Points Total--i.e., whether
``average'' refers to the average value within the measurement period
or the cumulative average value of RSS points at the time of
measurement. Id.
Accordingly, DOE proposed to clarify these provisions by providing
additional instructions for validating critical parameters in 10 CFR
429.134(s)(3)(ii). Id. Specifically, DOE proposed to specify that the
duration of the time period used for validating critical parameters
must be whichever of the following is longer: three minutes or the time
period needed to obtain five sample readings while meeting the minimum
data collection interval requirements of Table C2 of AHRI 1230-2021.
Id. DOE also proposed to specify that if at least one measurement
period (with the aforementioned duration) exists before the first
indoor unit goes thermally inactive that has an average RSS Points
Total less than or equal to 70 points, then the certified critical
parameter values are validated. Id.
a. Validation Time Period
Regarding DOE's proposal to clarify the language about the length
of time used for the critical parameter validation period, AHRI
commented that DOE should not specify a duration for the measurement
period used for validating critical parameters. AHRI argued that it is
not necessary to change existing language, as increasing testing
duration will not improve the ability of the equipment to conform to
testing conditions. (AHRI, No. 12 at pp. 3-4) Daikin commented that
while they agree with DOE's interpretation that technically a maximum
validation time period is not specified in AHRI 1230-2021, a longer
test run would result in a higher RSS point total. Daikin stated that
this is detrimental to determining whether the critical parameters are
valid and asserted that a manufacturer would likely test using the
shortest time period permitted by AHRI 1230-2021 (3 to 4 minutes).
(Daikin, No. 13 at p. 3) Despite both AHRI and Daikin indicating that a
maximum limit for critical parameter validation is not necessary, they
acknowledged that there may be merit in adding a maximum time period
and suggested changing this period to twice that proposed (i.e., 8
minutes). Daikin and AHRI provided three reasons to justify their
proposals: (1) there may be difficulty achieving all three critical
parameter values at the same time; (2) if any one critical parameter
achieves its target setpoint before the other critical parameters, the
system is penalized for going beyond the target setpoint; and (3) the
newness of the CVP results in greater uncertainty. (AHRI, No. 12 at pp.
3-4; Daikin, No. 13 at p. 3)

[[Page 63873]]

In response, DOE understands Daikin's comment to reflect a
misunderstanding of the calculation of the RSS points total, by
suggesting the potential for accumulating more points as more time
passes. As specified in Section C6.1.1 of AHRI 1230-2021, RSS points
total is calculated at each data collection interval during the R2
period \21\ as an instantaneous measurement, and, therefore, it does
not accumulate over time. AHRI's comments seemingly contradict each
other, as it in one place calls for an 8-minute maximum period while at
another place it states that a maximum period would have no effect.
With respect to AHRI and Daikin's claims about the timing with which
critical parameters achieve their target operating states, DOE is aware
of the possibility that system controls may achieve desired setpoints
for one critical parameter at a different time during the CVP than
other critical parameters. However, the purpose of the CVP is to
validate that the measured results of the IEER test procedure are based
on critical parameter settings that are representative of critical
parameter behavior that would be experienced in the field. Because the
measured performance of VRF multi-split systems is dependent on the
simultaneous interaction of each of the critical parameters, critical
parameter variation must be evaluated based on the simultaneous
positions of each parameter, not based on the behavior for each
parameter at different periods of the CVP. Therefore, DOE concludes
that for representative IEER test results, the critical parameter
settings used in IEER testing should be representative of a combination
of setpoints that would be used simultaneously in real-word
applications. If the desired critical parameter setpoints are achieved
in the CVP at times far enough apart that the RSS Points Total limit is
not met within the maximum length of validation period, then the
certified critical parameter settings should be invalidated (i.e., not
used for steady-state IEER testing). Daikin and AHRI also did not
provide any evidence to support their suggestion for increasing the
duration of the validation period beyond the duration in DOE's proposed
clarification of Sections C6.1.2 and C6.1.3 of AHRI 1230-2021. Because,
as discussed in section III.C.1 of this document, the Working Group
unanimously recommended that DOE adopt a test procedure referencing
AHRI 1230-2021, DOE understands AHRI 1230-2021 to represent the
industry consensus opinion. By extension, DOE understands the critical
parameter validation time period between 3-4 minutes specified in AHRI
1230-2021 to reflect consensus on an appropriate validation time
interval that provides for sufficient data collection and
representative results.
---------------------------------------------------------------------------

\21\ Section C4.4.2 of AHRI 1230-2021 defines the ``R2 period''
as beginning when the measured indoor dry-bulb temperature first
crosses from above 82 [deg]F to below 82 [deg]F, and as ending when
any indoor unit that was designated thermally active at the start of
the CVP becomes thermally inactive.
---------------------------------------------------------------------------

For the reasons discussed in the December 2021 VRF TP NOPR and in
the preceding paragraphs, in this final rule, DOE is adopting its
proposal to specify in 10 CFR 429.134(v)(3)(ii) the duration of the
time period used for validating critical parameters. The additional
instruction results in a validation period lasting a minimum of three
minutes and a maximum of four minutes. For tests using the longest
allowable data collection interval,\22\ the time required to obtain
five sample readings would be four minutes (once at the start of the
interval plus four successive measurements, once each minute). For
tests using shorter data collection intervals, the validation time
period would be either the time required to achieve five sample
readings or three minutes, whichever is longer.
---------------------------------------------------------------------------

\22\ Table C2 of AHRI 1230-2021 specifies the minimum data
collection intervals for recording data during the CVP.
---------------------------------------------------------------------------

b. Validation Criteria
Regarding DOE's proposal to validate certified critical parameters
based on the presence of a period (with duration discussed in section
III.E.4.a of this document) having an average RSS points total less
than or equal to 70 points, the CA IOUs commented that they agree that
the RSS Point Total budget of 70 points should be large enough to
account for any potential source of variability. (CA IOUs, No. 11 at
pp. 2-3) In contrast, AHRI and Daikin commented that CVP testing has
only been conducted on a limited subset of products, with very few
water-source products and no products over 240,000 Btu/h. These
commenters further asserted that no lab-to-lab test validation has been
conducted, especially between manufacturer laboratories and third-party
laboratories. AHRI and Daikin also asserted that manufacturers have
observed that changes in the indoor chamber temperature ramp rate
impact the unit's ability to meet the average RSS points total and to
reach conditions of the CVP. For these reasons, AHRI and Daikin
recommended that in the case that a CVP invalidates the certified
critical parameter settings during enforcement testing, DOE should
require that a second CVP be conducted at an adjusted ramp rate to re-
attempt validation. (AHRI, No. 12 at pp. 4-5; Daikin, No. 13 at pp. 3-
4)
Regarding AHRI and Daikin's claims about the potential for
variation between different CVP test runs, as discussed in section
III.E.1 of this final rule, the budget method (adopted at 10 CFR
429.134(v)(3)(ii) in this final rule) allows manufacturers flexibility
in critical parameter control strategies while still constraining the
overall variation in VRF multi-split system performance. Following
Working Group meetings, DOE conducted testing and sensitivity analysis
of several VRF multi-split systems, the results of which were
incorporated into the development of the budget method for CVP critical
parameter verification specified in Section C6 of AHRI 1230-2021. The
70-point threshold was developed as part of AHRI 1230 Technical
Committee meetings in which DOE presented anonymized and aggregated
test data. As part of those meetings, DOE presented its finding that a
minimum point budget of 32 points was required to account for the lab-
to-lab and test-to-test variability observed in critical parameter
behavior between CVP runs for a single system. (EERE-2018-BT-STD-0003-
0063 at p. 23) To account for additional variability (e.g., sample-to-
sample variability across the same VRF multi-split system and
variability across different types of VRF multi-split systems), DOE
recommended a 60-point budget to the Technical Committee. (Id) The
Technical Committee ultimately agreed to specify a 70-point budget in
AHRI 1230-2021. Additionally, in the December 2021 VRF TP NOPR, DOE
specifically requested test data demonstrating any issues with
repeatability and reproducibility of the CVP that would indicate that
the 70-point budget for critical parameter variation included in the
industry consensus test procedure AHRI 1230-2021 is insufficient. 86 FR
70644, 70662 (Dec. 10, 2021). DOE did not receive any data in response
to this request. For these reasons, DOE concludes that based on all
available data, the RSS points total budget of 70 points is
appropriately flexible to account for any issues with lab-to-lab and
unit-to-unit repeatability when conducting the CVP.
With regard to AHRI and Daikin's proposal to allow a second CVP to
be conducted at an alternate ramp rate, DOE does not have sufficient
information to support such an addition. As codified in this final
rule, manufacturers will be responsible for reporting in their STI
specific

[[Page 63874]]

instructions for conducting the CVP including ramp rate, starting
temperature, and thermally active indoor units. The CVP then includes
provisions for ensuring that the test laboratory properly conducts the
CVP per manufacturer specifications. Manufacturers also will be
required to report certified critical parameter values in their STI,
which the manufacturer may develop based on a CVP conducted using the
same instructions. These three provisions are all aligned to ensure the
CVP is performed consistently and that results are more predictable
(i.e., manufacturers can set their own ramp rate and CVP conditions,
within bounds of the test procedure, that would provide the most
consistent results). Additionally, DOE reiterates that the budget
method used for validating critical parameters was designed to give
enough flexibility to account for lab-to-lab and test-to-test variation
in CVP results. Allowing an additional CVP run to attempt validation of
critical parameters would in effect expand the uncertainty allowance
beyond that agreed upon by the AHRI 1230 Technical Committee and
addressed in AHRI 1230-2021. Therefore, in this final rule DOE is not
adopting the suggestion to allow a second CVP to be conducted at an
alternate ramp rate.
AHRI further commented that if DOE's proposals regarding CVP
validation of certified critical parameters were implemented as
enforcement guidance instead of through regulation, then the provisions
could be changed or rescinded more easily as industry gains experience
with conducting the CVP. (AHRI, No. 12 at p. 5)
As discussed, the CVP provisions (including the RSS points total
budget of 70 points) were developed using the data gathered by testing
several VRF multi-split systems. These data showed that a 70-point
budget would be sufficient to account for lab-to-lab and unit-to-unit
test variability. The provisions have also been thoroughly discussed in
Working Group and AHRI 1230 Technical Committee meetings prior to
inclusion in the most recent industry consensus test procedure AHRI
1230-2021. Therefore, DOE concludes that the CVP provisions are
appropriate for inclusion in DOE's regulations. Further, DOE finds that
codifying the CVP provisions in regulation provides greater certainty
for when and how the CVP would be used and prevents sudden shifts in
policy or interpretation.
Based on discussion in the December 2021 VRF TP NOPR and in the
preceding paragraphs, DOE is adopting its proposal at 10 CFR
429.134(v)(3)(ii) specifying that if at least one measurement period
(with the aforementioned duration) exists before the first indoor unit
goes thermally inactive that has an average RSS Points Total less than
or equal to 70 points, then the certified critical parameter values are
validated.
5. Determination of Alternate Critical Parameters
In the December 2021 VRF TP NOPR, DOE proposed that in cases in
which a CVP is not conducted, or if a CVP is conducted and the
manufacturer-specified critical parameters are validated, the critical
parameter values certified in the STI are to be used as the initial
control inputs when conducting the IEER cooling test at the
corresponding full- or part-load cooling condition. 86 FR 70644, 70661
(Dec. 10, 2021). In cases in which a CVP fails to validate the
certified critical parameter values, DOE proposed at 10 CFR
429.134(s)(3)(iii)(B) that alternate critical parameter values would be
determined by averaging the value for each critical parameter from a
specified time period of the CVP data, and that these alternate
critical parameter values would be used for IEER testing in lieu of the
certified critical parameter values. Id.
To provide further specification for determining these alternate
parameters, DOE proposed to use the same procedure for determination of
measurement period length as was proposed for validation of certified
critical parameters in 10 CFR 429.134(s)(3)(ii)(A): the longer of three
minutes or the time period needed to obtain five sample readings while
meeting the minimum data collection interval requirements of Table C2
of AHRI 1230-2021. 86 FR 70644, 70661 (Dec. 10, 2021). DOE also
proposed to select the measurement period for determining alternate
critical parameter values (with the aforementioned duration) that has
the lower average RSS points total over the selected period than over
any other period in the CVP having the same duration. Id. If multiple
such periods exist with the same RSS Points Total, DOE proposed to
select the period closest to (but before) the time when the first
indoor unit becomes thermally inactive (t<INF>Off</INF>). Id.
Daikin agreed that neither the Working Group nor the AHRI 1230
Technical Committee resolved the question of how to determine alternate
critical parameter values in the case where a CVP invalidates the
manufacturer's certified values. Daikin concurred with DOE's suggested
approach for determining alternate critical parameter settings.
(Daikin, No. 13 at p. 3) DOE did not receive any other comments
specific to the question of how to determine alternate critical
parameters following a CVP that fails to validate the manufacturer-
certified critical parameter settings. For the reasons discussed in the
December 2021 VRF TP NOPR and in this section, DOE is adopting the
provisions for determining alternate critical parameter values in this
final rule as proposed.

F. Allowable Critical Parameter Adjustment

1. Adjustment of Certified Critical Parameter Values
Section 6.3.3 of AHRI 1230-2021 provides instructions for adjusting
critical parameters during the four specified full- or part-load IEER
cooling test conditions in order to meet cooling capacity targets or to
adjust SHR to below the allowable limit. In the December 2021 VRF TP
NOPR, DOE tentatively determined that amendments to this section of
AHRI 1230-2021 are required and proposed to specify allowable critical
parameter adjustments in section 5.2 of appendix D1 to subpart F of
part 431. 86 FR 70644, 70662 (Dec. 10, 2021). Specifically, DOE
proposed (1) instructions for calculating critical parameter variation
(in terms of RSS Points Total) for steady-state IEER cooling tests for
which the measured capacity is above the target load fraction; (2)
clarification that upward adjustments to compressor speed (i.e., when
the measured cooling capacity is too low or when the SHR is above the
allowable limit) are not constrained by a budget on RSS Points Total;
and (3) clarification to the instructions for calculating critical
parameter variation in the scenario where a VRF multi-split system
contains multiple components corresponding to a single critical
parameter (e.g., multiple compressors). Id. at 86 FR 70662-70663.
Daikin expressed support for DOE's proposal to calculate normalized
critical parameter variation during the adjustment process if tested
capacity is above the target capacity and also supported the proposal
to adjust critical parameters to meet capacity requirements. (Daikin,
No. 13 at p. 4) AHRI supported the clarifications proposed by DOE and
commented that the Department should provide example calculations for
each case so as to provide additional clarity. Specifically, AHRI
mentioned that for systems with multiple modules (i.e., outdoor units),
there are two types of critical parameters: (1) those that can be set
for each module and (2) those that have one

[[Page 63875]]

value for multiple modules. (AHRI, No. 12 at p. 6)
For the reasons discussed in the December 2021 VRF TP NOPR and in
the preceding paragraphs, DOE is finalizing its proposals to add
clarifying language to the provisions for determining allowable
critical parameter adjustments when conducting IEER testing.
Regarding AHRI's request that DOE provide example calculations for
``each case'' describing allowable critical parameter adjustments, the
scope of AHRI's suggestion is unclear (e.g., whether AHRI requested
example calculations for different equipment classes of VRF multi-split
systems or for different permutations of critical parameters). Further,
DOE finds that the proposed instructions for critical parameter
adjustments are sufficient for testing multi-module VRF multi-split
systems, even if parameters are controlled jointly across modules.
Section 5.2 of appendix D1 describes critical parameter adjustments and
includes provisions that accommodate differential or shared adjustments
of multiple instances of the same critical parameter (e.g., two
compressors). Because the existing test provisions sufficiently cover
the scenario described by AHRI, and because AHRI did not provide any
other examples of VRF multi-split system configurations or control
schemes for which the proposed testing provisions for critical
parameter adjustments are unclear, DOE is not adding example
calculations for critical parameter adjustments in this final rule.
In the case that a VRF multi-split system configuration exists that
raises questions about how the DOE test procedure should apply, DOE
notes that it will receive general inquiries via email at
<a href="/cdn-cgi/l/email-protection#9ddcededf1f4fcf3fef8cee9fcf3f9fceff9eecce8f8eee9f4f2f3eeddf8f8b3f9f2f8b3faf2eb">[email&#160;protected]</a>. DOE also maintains a repository
of frequently asked questions pertaining to additional guidance issued
by DOE.\23\ In addition, if it is ultimately determined that a VRF
multi-split system configuration exists for which the critical
parameter adjustment procedures will result in an inability to test the
system or provide materially inaccurate performance results,
manufacturers may petition DOE for a test procedure waiver under 10 CFR
431.401.
---------------------------------------------------------------------------

\23\ DOE's website houses frequently asked questions (FAQs)
pertaining to the DOE Appliance Standards Program. The FAQ list is
available at: <a href="https://www.energy.gov/eere/buildings/appliance-standards-guidance-and-frequently-asked-questions">https://www.energy.gov/eere/buildings/appliance-standards-guidance-and-frequently-asked-questions</a>-faqs, or
interested parties may submit a new question at: <a href="https://www.energy.gov/eere/buildings/appliance-standards-guidance-and-frequently-asked-questions">https://www.energy.gov/eere/buildings/appliance-standards-guidance-and-frequently-asked-questions</a>.
---------------------------------------------------------------------------

2. Adjustment of Alternate Critical Parameter Values
As described in section III.E.5 of this document, DOE proposed to
clarify how, in the event that a manufacturer's certified critical
parameter settings were invalidated through the CVP, alternate critical
parameters would be determined and used as control inputs during DOE
enforcement testing. 86 FR 70644, 70663 (Dec. 10, 2021). In the
December 2021 VRF TP NOPR, DOE elaborated that in such a case, it may
still be necessary to adjust the alternate critical parameter values in
order to meet capacity tolerances and SHR limits for the IEER test.
Accordingly, DOE proposed to include provisions at 10 CFR
429.134(s)(3)(iii)(B)(3) specifying that in the case of invalidated
critical parameter values in which DOE determines alternate critical
parameters, additional adjustments to the alternate critical parameters
are allowed in order to comply with capacity and/or SHR requirements.
Id.
Specifically, DOE proposed to rely on the methods for adjustment of
critical parameters in proposed section 5.2 of appendix D1 to subpart F
of part 431 with two modifications. Id. First, DOE proposed that in
such a case, references in section 5.2 of appendix D1 to critical
parameter values certified in the STI would be replaced with references
to alternate critical parameter values determined under the CVP.
Second, DOE proposed to determine the maximum operating state of each
critical parameter (referred to as CP<INF>Max</INF> in AHRI 1230-2021
and the proposed regulatory text) based on the maximum operating state
observed during a CVP conducted at 100-percent cooling load conditions,
instead of using the information certified to the STI for the 100-
percent cooling load point. Id.
AHRI commented that it supports DOE's proposal to use alternate
critical parameters for IEER adjustments in the case of invalidated STI
critical parameters, as this proposal clarifies how a test would be run
in this situation. (AHRI, No. 12 at p. 6) Daikin commented that DOE's
proposed adjustments to meet capacity requirements, if not provided by
the manufacturer in the STI, is acceptable. (Daikin, No. 13 at p. 4)
DOE did not receive any additional comments on this topic.
Based on the discussion presented in the December 2021 VRF TP NOPR
and in the preceding paragraphs, DOE is adopting its proposals for
section 5.2 of appendix D1 to subpart F of part 431 regarding
adjustment of alternate critical parameter values.

G. Certification, Compliance, and Enforcement

1. Determination of Represented Values
a. Introduction
VRF multi-split systems are, by definition, split-system commercial
package air conditioners and heat pumps that employ an outdoor unit(s)
and multiple separate indoor fan coil units connected in a single
refrigerant circuit. 10 CFR 431.92. VRF multi-split heat pumps can be
configured as heat recovery systems, which allows for recovered energy
from the indoor units operating in one mode (e.g., cooling) to be
transferred to one or more other indoor units operating in the other
mode (e.g., heating). This necessitates a heat recovery box that is
installed between the outdoor unit and indoor units. Additionally, VRF
multi-split systems are available with different refrigerant options
and are sold with a wide variety of components, including many that can
optionally be installed on or within the unit, both in the factory and
in the field. Each optional component may or may not affect a model's
measured efficiency when tested to the DOE test procedure adopted in
this final rule.
In the December 2021 VRF TP NOPR, DOE proposed several items
related to configuration of the unit under test and determination of
represented values. These proposals included instructions on how to
select indoor unit models (via reference of the tested combination
requirements specified in section 6.2.1 of AHRI 1230-2021) and
provisions specifying the different represented values that must be
made for each indoor unit type within a basic model, as well as
provisions for determination of represented values for basic models
distributed in commerce with specific components, heat recovery
components, and multiple refrigerants. 86 FR 70644, 70663-70665 (Dec.
10, 2021). These proposals and related stakeholder comments are
discussed in paragraph III.G.1.b of this document.
In this final rule, DOE is providing additional discussion to help
clarify the interplay between the previously proposed representation
requirements, the proposed indoor unit tested combination requirements,
and the proposed approach for specific components. The approach
finalized by this rule is substantively the same as the corresponding
proposals in the December 2021 VRF TP NOPR. The provisions adopted in
this final rule and the justification for adopting these

[[Page 63876]]

provisions are described in greater detail in section III.G.1.c of this
document.
b. NOPR Proposals and Comments
i. Tested Combination and Indoor Unit Combinations
In the December 2021 VRF TP NOPR, DOE made two proposals pertaining
to represented values for different combinations of VRF indoor unit
models. First, DOE proposed to reference the tested combination
provisions from section 6.2.1 of AHRI 1230-2021 in the test procedure
at appendix D1. 86 FR 70644, 70663 (Dec. 10, 2021). These provisions
instruct how to select indoor unit models to comprise a ducted, non-
ducted, or small-duct high-velocity tested combination. Section 6.2.1
also specifies an indoor unit selection hierarchy based on indoor unit
sub-type and other design characteristics. For example, to compose a
non-ducted tested combination, AHRI 1230-2021 specifies compact 4-way
ceiling cassettes as the highest-priority selection and further
requires that the indoor unit model having the lowest normalized coil
volume and lowest-efficiency indoor fan motor within the specified
indoor unit type must be selected. Second, DOE proposed that
manufacturers must determine separate represented values for each
indoor unit tested combination that is distributed in commerce. 86 FR
70644, 70664 (Dec. 10, 2021). Through this approach, each VRF basic
model would be required to include separate representations for each of
the ducted, non-ducted, and small-duct, high-velocity indoor unit
tested combinations (if distributed in commerce in such a combination).
DOE also proposed that manufacturers would be allowed to make optional
``mixed'' representations based on the simple average of represented
values of any two tested combinations within a basic model. Id.
In response, AHRI, Carrier, and Daikin commented that they support
DOE's proposals for determining represented values for different indoor
unit combinations/mixed combinations. (AHRI, No. 12 at p. 6; Carrier,
No. 7 at p. 1; Daikin, No. 13 at p. 5). DOE did not receive any
comments specially addressing its proposal to reference the tested
combination provisions from section 6.2.1 of AHRI 1230-2021.
ii. Treatment of Specific Components
AHRI 1230-2021 outlines requirements for specific components in
Appendix F, ``Unit Configuration for Standard Efficiency
Determination--Informative.'' Appendix F provides discussion of
components which would not be considered in representations, and
provides instructions either to minimize their impact during testing or
to determine representations for individual models with such components
based on other individual models that do not include them. In the
December 2021 VRF TP NOPR, instead of referencing Appendix F of AHRI
1230-2021, DOE tentatively determined that it was necessary to adopt
similar instructions in a more comprehensive manner, so the Department
proposed provisions in the appendix D1 test procedure, in the
representation requirements at 10 CFR 429.43, and in the enforcement
provisions at 10 CFR 429.134. 86 FR 70644, 70657 (Dec. 10, 2021).
Specifically, DOE proposed test provisions in section 6 of appendix
D1 that instructed how to test a VRF multi-split system equipped with
any specific component(s) listed in Table 6.1 \24\ of that same
section. 86 FR 70644, 70686 (Dec. 10, 2021). These provisions were
designed to minimize the impact on measured performance caused by
testing with the specific component(s) present. Additionally, DOE
proposed representation requirements in 10 CFR 429.43(a)(4) that
explicitly allowed representations for individual models with certain
components to be based on testing for individual models without those
components; the proposal included a table in 10 CFR 429.43(a)(4)(i)
listing the two components for which these provisions would apply (air
economizers and desiccant dehumidification components). 86 FR 70644,
70657-70658 (Dec. 10, 2021). DOE also proposed corresponding product
enforcement provisions in 10 CFR 429.134 indicating that DOE would
conduct enforcement testing on VRF multi-split systems having
individual indoor unit models that do not include air economizers or
dehumidification components, except in certain circumstances. 86 FR
70644, 70658 (Dec. 10, 2021).
---------------------------------------------------------------------------

\24\ Table 6.1 includes test provisions for VRF multi-split
systems equipped with desiccant dehumidification components, air
economizers, fresh air dampers, hail guards, low ambient cooling
dampers, power correction capacitors, and/or ventilation energy
recovery systems (VERS). 86 FR 70644, 70686-70687 (Dec. 10, 2021).
---------------------------------------------------------------------------

DOE also proposed to adopt language more specific to VRF multi-
split systems, as compared to the general language contained in section
F2.4 of AHRI 1230-2021. Specifically, DOE proposed to use the term
``individual indoor unit models'' to account for potential
discrepancies across individual indoor unit models that comprise the
VRF multi-split system tested combination. 86 FR 70644, 70657 (Dec. 10,
2021). DOE's proposed approach would allow for the individual
consideration of specific components on an indoor unit-by-indoor unit
basis to account for scenarios in which individual indoor unit models
in the tested combination differ in components.
For two components--coated coils and steam/hydronic heat coils--DOE
did not propose to include these components in the list of specific
components warranting enforcement relief (i.e., provisions in 10 CFR
429.43(a)), nor did DOE propose any provisions to minimize their impact
during testing (i.e., provisions in appendix D1). DOE noted that coated
coils and steam/hydronic heat coils were not included in the list of
optional features in Section F2.4 of AHRI 1230-2021, and determined the
industry consensus to be that coated coils and steam/hydronic heat
options should not be treated as optional features for VRF multi-split
systems and/or that VRF multi-split systems are not distributed in
commerce with these features. 86 FR 70644, 70657 (Dec. 10, 2021).
Finally, DOE stated that, were DOE to adopt the provisions in
appendix D1, 10 CFR 429.43, and 10 CFR 429.134 as proposed, DOE would
rescind the Commercial HVAC Enforcement Policy to the extent it is
applicable to VRF multi-split systems. 86 FR 70644, 70658 (Dec. 10,
2021).
In comments on the December 2021 VRF TP NOPR, Lennox, AHRI, and
Carrier stated that they support DOE's proposal to include test
provisions for specific components, as outlined in Table 6.1 of
Appendix D1. (Lennox, No. 8 at p. 2; AHRI, No. 12 at p. 2; Carrier, No.
7 at p. 1) Further, AHRI encouraged DOE to specifically exclude VRF
multi-split systems from the Commercial HVAC Enforcement Policy going
forward so as to avoid confusion. (AHRI, No. 12 at p. 2) Daikin
commented that coated coils, low ambient cooling dampers, and power
correction capacitors are a part of the outdoor unit model and asserted
that a clarification was needed at 10 CFR 429.43(a)(4) to designate
both indoor and outdoor unit models, as opposed to just indoor unit
models. (Daikin, No. 13 at p. 2)
With respect to DOE's proposals to exclude coated coils and steam/
hydronic heat coils from the testing provisions and from consideration
when determining represented values, Lennox, AHRI, and Daikin all
commented that DOE should also consider including coated coils and

[[Page 63877]]

steam/hydronic heat coils in table 6.1, as contained in the DOE
Commercial HVAC Enforcement Policy. (Lennox, No. 8 at p. 2; AHRI, No.
12 at p. 2; Daikin, No. 13 at p. 2) AHRI asserted that coated coils
should not be required for testing because units will always be
available without them (i.e., represented values should not be required
to be based on a VRF multi-split system with coated coils when there
would always be an otherwise comparable model available without coated
coils). (AHRI, No. 12 at p. 2) Daikin stated that adding steam/hydronic
coils to table 6.1 would align regulations for VRF multi-split systems
with those for other equipment categories, and that coated coils, low
ambient cooling dampers, and power correction capacitors might be
included in the outdoor section of VRF multi-split systems. (Daikin,
No. 13 at p. 2)
In response, DOE has considered these comments and has determined
that clarifications are warranted to the approach proposed in the
December 2021 VRF TP NOPR regarding the treatment of certain components
for determining represented values. Therefore, DOE is adopting the
proposals made in the December 2021 VRF TP NOPR, with clarifications
that are discussed in detail in section III.G.1.c of this final rule.
iii. Heat Recovery Components
Section 5.6 of AHRI 1230-2021 specifies that for all VRF heat
recovery systems, the heat recovery control unit must be attached
during all tests. Similarly, section F2.3 of AHRI 1230-2021 requires
that all heat recovery components must be present and installed for
testing individual models distributed in commerce with these
components. DOE proposed in the December 2021 VRF TP NOPR to reference
Section 5.6 of AHRI 1230-2021 in its proposed test procedures for VRF
multi-split systems at appendix D1. 86 FR 70644, 70651 (Dec. 10, 2021).
Consistent with section F2.3 of AHRI 1230-2021, DOE also proposed to
specify in 10 CFR 429.43(a) that for basic models of VRF multi-split
systems distributed in commerce with heat recovery components, the
manufacturer must determine represented values for the basic model
based on performance of an individual model distributed in commerce
with heat recovery components. 86 FR 70644, 70656 (Dec. 10, 2021).
DOE did not receive any comments regarding heat recovery components
in response to the December 2021 VRF TP NOPR. In this final rule, DOE
is finalizing its proposed test provisions in appendix D1 but is
removing its proposal to specify in 10 CFR 429.43(a) that VRF multi-
split systems distributed in commerce with heat recovery components
must determine represented value based on a configuration of the basic
model with heat recovery components installed, as discussed in section
III.G.1.c.ii of this final rule.
iv. Multiple Refrigerants
DOE proposed in the December 2021 VRF TP NOPR that in cases in
which a basic model of VRF multi-split system can be used with multiple
refrigerants without requiring different hardware, then a manufacturer
must determine the represented values (e.g., IEER, COP, and cooling
capacity) for that basic model based on the refrigerant(s)--among all
refrigerants listed on the unit's nameplate--that result in the lowest
cooling efficiency. 86 FR 70644, 70665 (Dec. 10, 2021). DOE also
clarified that, should the use of a different refrigerant require
different hardware, this would represent a different basic model and,
consequently, separate representations of energy efficiency would be
required. Id.
The Joint Advocates, Lennox, and the CA IOUs expressed support for
DOE's proposal to use the refrigerant listed on the unit's nameplate
that results in the lowest cooling efficiency for represented values.
(Joint Advocates, No. 9 at p. 1; Lennox, No. 8 at p. 3; CA IOUs, No. 11
at p. 4) The Joint Advocates commented that DOE's proposal would ensure
that when manufacturers test a basic model, a refrigerant would not be
selected that overstates the efficiency of the equipment as compared to
if it were charged with another (less-efficient) refrigerant in the
field. (Joint Advocates, No. 9 at p. 1) The Joint Advocates and the CA
IOUs recommended allowing manufacturers to make additional
representations for a basic model using different (i.e., more-
efficient) refrigerants to demonstrate the benefits of using more-
efficient refrigerants. (Joint Advocates, No. 9 at p. 1; CA IOUs, No.
11 at p. 4)
DOE has considered these comments and has determined that the
multiple refrigerant proposals made in the December 2021 VRF TP NOPR
are not needed because the approach for determining represented values
adopted in this final rule addresses the issue consistent with the NOPR
proposals without need to specifically address multiple refrigerants.
This matter is discussed in greater detail in section III.G.1.c of this
final rule.
c. Final Rule Approach
i. Summary
As previously introduced, DOE is finalizing an approach for
determining represented values that improves the clarity of, but is not
substantively different than, the proposals in the December 2021 VRF TP
NOPR. In this final rule, DOE is amending language in 10 CFR
429.43(a)(3)(ii) to clarify the interplay between the indoor unit
tested combination, the representation requirements pertaining to
specific components, and general requirements pertaining to represented
values. DOE has structured the provisions at 10 CFR 429.43(a)(3)(ii) to
reflect the different considerations when selecting outdoor vs. indoor
units, and to highlight that the specific components currently subject
to DOE enforcement relief (i.e., desiccant dehumidification components
and air economizers) are only applicable at the level of indoor units
within a tested combination, not at the basic model level. DOE is
specifying that for each indoor unit combination within a basic model
(i.e., ducted, non-ducted, or SDHV), the representation must be based
on a combination of: (1) the least-efficient outdoor unit model
distributed in commerce for that particular basic model which would be
based on the least-efficient refrigerant (as discussed in section
III.G.1.c.ii of this document); and (2) the combination of indoor units
selected in accordance with the criteria described in section
III.G.1.c.iii of this document. By taking this approach, DOE is
clarifying the interaction between long-standing basic model
provisions, tested combination requirements, and the treatment of
specific components for VRF multi-split systems.
ii. Outdoor Unit and Heat Recovery
In this final rule DOE is: (1) clarifying that the least-efficient
outdoor unit model within a basic model must be used for determining
represented values; and (2) clarifying that the test procedure requires
that VRF multi-split heat pumps with heat recovery must be tested with
heat recovery components present, but without the need for
representation requirements as initially proposed. DOE is not adopting
any exemptions to the ``least-efficient'' requirement for outdoor
unit(s) used to determine represented values because neither of the
specific components listed in Table 2 to 10 CFR 429.43(a)(3)(ii)(B)
(i.e., air economizers and desiccant dehumidification components--as
adopted in this final rule) are applicable for VRF outdoor units.

[[Page 63878]]

With respect to comments received regarding multiple refrigerants
available for a basic model of VRF multi-split system, because the
efficiency of the VRF multi-split system could be impacted by different
refrigerant choices, the least-efficient outdoor model requirement
necessitates consideration of the least-efficient refrigerant when
determining represented values for that basic model. Upon further
consideration, DOE has determined that the proposal in the December
2021 VRF TP NOPR regarding multiple refrigerants is already included
substantively in the provision adopted at 10 CFR 429.43(a)(3) regarding
least-efficient outdoor units, and that additional provisions would be
redundant. As such, in this final rule, DOE is not adopting the
refrigerant-specific language at 10 CFR 429.43(a)(3) that was proposed
in the December 2021 NOPR.
Regarding heat recovery components, as described in section
III.G.1.b.iv of this document, DOE proposed related testing provisions
in appendix D1 and representation provisions in 10 CFR 429.43(a). In
this final rule, DOE is finalizing its proposed test provisions in
appendix D1 but is removing its proposal to specify in 10 CFR 429.43(a)
that VRF multi-split systems distributed in commerce with heat recovery
components must determine represented value based on a configuration of
the basic model with heat recovery components installed. Upon further
review of the test provisions referencing section 5.6 of AHRI 1230-
2021, DOE has determined that all VRF multi-split heat pumps with heat
recovery capability would always be required by to be configured with
heat recovery components installed. Further, DOE's energy conservation
standards for VRF multi-split systems specified at 10 CFR 431.97
classify systems with and without heat recovery to be in different
equipment classes, such that a given VRF basic model does not contain
systems with and without heat recovery (as such systems are certified
under separate equipment classes).\25\ The combination of these
provisions ensures that represented values for VRF multi-split heat
pumps with heat recovery are always determined with heat recovery
components installed. Therefore, DOE finds its earlier proposal to be
unnecessary, and accordingly, the Department is not adopting
represented value provisions related to heat recovery components in
this final rule.
---------------------------------------------------------------------------

\25\ DOE distinguishes certain VRF equipment classes by ``with
heat recovery'' and ``without heat recovery'', and other equipment
classes with ``no heating or electric resistance heating'' and ``all
other types of heating.'' Footnote 1 to Table 13 to 10 CFR 431.97
specifies that VRF systems with heat recovery fall under the
category of ``all other types of heating'' unless they also have
electric resistance heating. In the March 2022 VRF ECS NOPR, DOE
proposed to amend 10 CFR 431.97 to adopt the equipment class
structure found in ASHRAE Standard 90.1-2016 for VRF multi-split
systems, which, if adopted would create separate equipment classes
for VRF heat pumps with and without heat recovery for all capacity
ranges and heat rejection media (i.e., replacing any class
distinctions based on supplementary heating type). 87 FR 11335,
11346 (March 1, 2022).
---------------------------------------------------------------------------

iii. Indoor Unit Specification
DOE made several proposals in the December 2021 VRF TP NOPR
pertaining to the selection of indoor unit models when determining
represented values for the basic model of VRF multi-split system. 86 FR
70644, 70664-70665 (Dec. 10, 2021). As discussed elsewhere in this
document, DOE proposed provisions related to different tested
combinations of indoor units (see section III.G.1.b.i of this
document), certification reporting requirements (see section III.G.2 of
this document), and provisions related to treatment of specific
components (see section III.G.1.b.ii of this document).
As described in section III.G.1.b.i of this document, DOE received
only supportive comments in response to its proposals for determining
represented values for different indoor unit tested combinations (i.e.,
ducted, non-ducted, SDHV, and mixed representations thereof). In light
of these comments and the reasoning provided in the December 2021 VRF
TP NOPR, DOE is adopting its earlier proposals pertaining to this topic
in this final rule.
The adopted provisions provide guidance for determining required
represented values of indoor unit combinations (i.e., ducted, non-
ducted, SDHV) and provide guidance for determining optional mixed
representations that are determined by taking a simple average of any
two of the required representations. By adopting these provisions, each
VRF outdoor unit may include up to six separate representations within
the same basic model number.
Regarding certification requirements, as discussed in greater
detail in section III.G.2 of this document, DOE proposed to require
that manufacturers publicly report the indoor unit combination (i.e.,
ducted, non-ducted, SDHV, or mixed) used to determine represented
values, as well as all outdoor and indoor unit model numbers used to
compose the tested combination. For the reasons discussed in the
December 2021 VRF TP NOPR and in section III.G.2.a of this document,
DOE is adopting these amended certification requirements as proposed.
DOE also proposed to require that manufacturers supply information in
their STI regarding whether specific components were present or absent
when determining represented values for the basic model. As discussed
in section III.G.2.b of this document, DOE is not adopting
certification requirements related to specific components in this final
rule.
Regarding specific components, DOE is clarifying the provisions at
10 CFR 429.43(a)(3) that cover the determination of represented values
for VRF multi-split systems. In the December 2021 VRF TP NOPR, DOE
proposed to individually consider specific components on an indoor-
unit-by-indoor unit basis when determining represented values. 86 FR
70644, 70657 (Dec. 10, 2021). DOE's approach in this final rule is
consistent with the approach in the NOPR in that it requires
consideration of specific components for each indoor unit individually,
rather than at the basic model level. DOE has also introduced the
concept of ``fully-specified'' indoor unit model numbers in order to
provide greater clarity about selection of indoor units and to
explicitly tie these requirements to the aforementioned certification
requirements.
For cases where an indoor unit model number is fully specified in
the public certification (i.e., the indoor unit model number includes
sufficient information to identify the presence or absence of all
components), DOE will require that the indoor unit model number,
precisely as it appears as certified, shall be used for determining
represented values. For example, for an indoor unit whose certified
model number affirmatively designates the presence of dehumidification
components, represented values must be determined based on the indoor
unit model with dehumidification components installed, regardless of
whether otherwise comparable indoor units are distributed in commerce
without dehumidification components present. This approach does not
conflict with the tested combination requirements in section 6.2 of
AHRI 1230-2021, which sets minimum criteria for indoor model
specification and does not disallow further specification (including
specification of dehumidification components and/or air economizers).
For cases where an indoor unit model number is not fully-specified
as part of the certified tested combination (i.e., where the model
number is constructed in such a way that does not fully specify

[[Page 63879]]

the absence or presence of all components), DOE is applying the
represented value requirements as proposed in the NOPR. This approach
requires that for indoor unit model numbers that are not fully-
specified in the certification, a fully-specified indoor unit must be
selected to determine represented values for the basic model. This
fully-specified indoor model number must be consistent with the
certified indoor unit model number (i.e., all specified digits must
match), and, among the group of all indoor unit models having a
consistent model number, must have the least number (which may include
zero) of specific components (i.e., air economizers and desiccant
dehumidification components) installed.
Regarding DOE's proposed testing provisions for specific components
in 10 CFR 431, subpart F, appendix D1, DOE is adopting the proposals
from the December 2021 VRF TP NOPR. Specifically, DOE is finalizing
provisions in section 6 to appendix D1 that provide instruction how to
test a VRF multi-split system equipped with any specific component(s)
listed in Table 6.1 \26\ of that same section.
---------------------------------------------------------------------------

\26\ Table 6.1 includes test provisions for VRF multi-split
systems equipped with desiccant dehumidification components, air
economizers, fresh air dampers, hail guards, low ambient cooling
dampers, power correction capacitors, and/or ventilation energy
recovery systems (VERS).
---------------------------------------------------------------------------

As discussed, DOE received comments suggesting that DOE should
consider including coated coils and steam/hydronic heat coils in the
list of specific components in table 6.1 to appendix D1. DOE also
received similar comments pertaining to coated coils in response to
other commercial HVAC equipment test procedure NOPRs, specifically the
test procedure supplemental notice of proposed rulemaking (``SNOPR'')
published for direct expansion-dedicated outdoor air systems (``DX-
DOASes'') \27\ (Docket No. EERE-2017-BT-TP-0018, AHRI, No. 34 at p. 4).
In response to the DX-DOAS SNOPR, AHRI and Madison Indoor Air Quality
(``MIAQ'') asserted that some coated coils impact performance, but that
each coating is different (Docket No. EERE-2017-BT-TP-0018, AHRI, No.
34 at p. 4; MIAQ, No. 29 at p. 4).
---------------------------------------------------------------------------

\27\ See 86 FR 72874 (Dec. 23, 2021).
---------------------------------------------------------------------------

AHRI and MIAQ's assertion that some coated coils do impact energy
use suggests that there are other implementations of coated coils that
do not impact energy consumption as measured by the adopted test
procedure (i.e., the implementation of coated coils does not
necessarily or inherently impact energy use). DOE has no data
indicating the range of impacts for those coatings that do affect
energy use, or how other characteristics of the coatings, such as
durability and cost, correlate with energy use impacts. Absent such
data, DOE is unable to determine the specific range of impacts on
energy use made by coated coils. Nevertheless, given that comments on
the DX-DOAS SNOPR suggest that certain implementations of coated coils
do not impact energy use, DOE has determined that for those units for
which coated coils do impact energy use, representations should include
those impacts, thereby providing full disclosure for commercial
customers. Consequently, DOE is not incorporating coated coils into
DOE's provisions specified in 10 CFR 429.43(a)(3) which allow for the
exclusion of specified components when determining represented values
for VRF multi-split systems. This approach is consistent with the one
DOE has established in a final rule for the DX-DOAS test procedure. 87
FR 45164, 45186 (July 27, 2022).
Commenters did not indicate whether models are available with
steam/hydronic heat, thereby supporting DOE's tentative conclusion in
the December 2021 VRF TP NOPR that steam/hydronic heat components are
not present in VRF multi-split systems and/or models with these
components are not distributed in commerce. 86 FR 70644, 70657 (Dec.
10, 2021). Consequently, DOE is finalizing its proposal to exclude
steam/hydronic heat from the specific components list for VRF multi-
split systems in 10 CFR 429.43(a)(3).
As proposed in the December 2021 VRF TP NOPR, DOE sought to address
VRF multi-split systems that include the specified excluded components
both in the requirements for representation (i.e., 10 CFR 429.43) and
as part of the equipment specific enforcement provisions for assessing
compliance (i.e., 10 CFR 429.143). 86 FR 70644, 70656-70658 (Dec. 10,
2021). Instruction on which units to test for the purpose of
representations are addressed in 10 CFR 429.43. DOE has determined that
including parallel enforcement provisions in 10 CFR 429.134 would be
redundant and potentially cause confusion, because DOE would select for
enforcement only those individual models that are the basis for making
basic model representations as specified in 10 CFR 429.43. Therefore,
in this final rule, DOE is providing the requirements for making
representations of VRF multi-split systems that include the specified
components in 10 CFR 429.43, and is not including parallel direction in
the enforcement provisions of 10 CFR 429.134 established in this final
rule. However, DOE is finalizing the provision that allows enforcement
testing of alternative individual models with specific components, if
DOE cannot obtain for test the individual models without the components
that are the basis of the representation.
In regards to the NOPR proposal that DOE shall rescind the
commercial HVAC enforcement policy for VRF multi-split systems, DOE has
provided substantive guidance for each component included in both the
DOE Enforcement Policy and the ``Equipment Features Requiring Test
Procedure Action'' from the term sheet agreed upon by an ASRAC working
group for certain commercial HVAC equipment (``Commercial HVAC CCE Term
Sheet'').\28\ (EERE-2013-BT-NOC-0023-0052) Consequently, these
documents would no longer be applicable to VRF multi-split systems and
could potentially cause confusion. To prevent this confusion, DOE is
clarifying in this final rule that the provisions established in this
final rule will take precedence over those in the DOE Enforcement
Policy and the Commercial HVAC CCE Term Sheet, and that the
aforementioned documents will no longer be applicable to VRF multi-
split systems. As previously discussed, this change will not take
effect until the compliance date of amended energy conservation
standards for VRF multi-split systems denominated in terms of IEER,
should DOE adopt such standards.
---------------------------------------------------------------------------

\28\ In 2013, members of ASRAC formed the Commercial HVAC
Working Group to engage in a negotiated rulemaking effort regarding
the certification of certain commercial HVAC equipment, including
VRF multi-split systems. The Commercial HVAC Working Group's
recommendations are available at <a href="http://www.regulations.gov">www.regulations.gov</a> under Docket
No. EERE-2013-BT-NOC-0023-0052.
---------------------------------------------------------------------------

2. Certification Reporting Requirements
a. Certification Requirements
DOE specifies certification reporting requirements for VRF multi-
split systems in 10 CFR 429.43(b). Certification reporting requirements
for VRF multi-split systems include both public equipment-specific
information and STI. As previously described, in the December 2021 VRF
TP NOPR DOE proposed to amend the certification reporting requirements
for VRF multi-split systems to address the IEER metric but did not
propose amendments to the current standards (in terms of EER). 86 FR
70644, 70665 (Dec. 10, 2021). Subsequently, in the March 2022 VRF ECS
NOPR DOE proposed to amend

[[Page 63880]]

standards for VRF multi-split systems to be in terms of the IEER
cooling metric, with a proposed compliance date of January 1, 2024. 87
FR 11335, 11349 (March 1, 2022). Therefore, the amended certification
reporting requirement proposals would only apply when certifying to a
future IEER standard; existing certification reporting requirements
used when certifying to the current EER standards would not change. In
the December 2021 VRF TP NOPR, DOE proposed to add the following items
to the public certification reporting requirements for VRF multi-split
systems:
<bullet> IEER values (replacing the current certification
requirement for EER values);
<bullet> The rated heating capacity, in Btu/h;
<bullet> The indoor unit combination used to determine the
represented values for an individual combination (i.e., a non-ducted,
ducted, SDHV, or mixed indoor unit combination), and all outdoor and
indoor unit model numbers used to compose the tested combination; and
<bullet> The refrigerant used to determine the represented values
for a basic model (e.g., EER, IEER, COP, and cooling capacity).

86 FR 70644, 70665 (Dec. 10, 2021). A draft certification template
reflecting the proposed changes has been included in the docket.\29\
---------------------------------------------------------------------------

\29\ The draft certification template columns can be found in
the docket at: <a href="http://www.regulations.gov/document/EERE-2021-BT-TP-0019-0001">www.regulations.gov/document/EERE-2021-BT-TP-0019-0001</a>.

In response to DOE's certification proposals, the Joint Advocates
commented that they support DOE's proposal to publicly report the
heating capacity for VRF multi-split systems, stating that this
requirement aligns with reporting requirements for the cooling metric
and that consumers would be interested in this information. (Joint
Advocates, No. 9 at p. 1) The CA IOUs supported DOE's certification
proposals but requested that the certification report should clarify
that COP is measured per the ``high temperature'' heating test at 47
[deg]F, to prevent confusion with other temperatures at which heating
COP tests can be conducted. As introduced in section III.G.1.b.v of
this document, the CA IOUs also recommended allowing manufacturers to
make additional representations for a basic model using different
(i.e., more-efficient) refrigerants. (CA IOUs, No. 11 at p. 3) The CA
IOUs suggested a corresponding certification requirement that the
global warming potential (GWP) of each refrigerant be listed along with
the performance information. (CA IOUs, No. 11 at p. 4)
With respect to the CA IOUs' comment requesting clarification of
the COP heating condition in the certification report, as discussed in
section III.D.2 of this document, DOE acknowledges the need to clarify
that the ratings for heating mode tests of air-cooled VRF multi-split
heat pumps used for compliance with standards are those referred to as
``High Temperature Steady-state Test for Heating'' in AHRI 1230-2021
and measured at 47 [deg]F outdoor ambient air temperature.
Additionally, DOE acknowledges the need to clarify that the ratings for
heating mode tests of water-source VRF multi-split heat pumps used for
compliance with standards are those specified for ``Water Loop Heat
Pumps'' in AHRI 1230-2021 and measured at 68 [deg]F entering liquid
temperature. Consistent with the test procedure provisions adopted in
this final rule (as discussed in section III.D.2 of this document) and
the CA IOUs' suggestion, DOE is amending the certification template to
read ``Coefficient of Performance, measured at 47 [deg]F for air-source
VRF multi-split heat pumps or measured at 68 [deg]F Entering Water
Temperature for water-source VRF multi-split heat pumps.''
With respect to the CA IOU's comments regarding certification
requirements for VRF multi-split systems available with multiple
refrigerants, DOE has concluded that because the efficiency of the VRF
multi-split system could be impacted by different refrigerant choices,
the least-efficient outdoor model requirement necessitates
consideration of the least-efficient refrigerant when determining
represented values for that basic model (see discussion in III.G.1.c.ii
of this document). In this final rule, DOE is also finalizing its
proposal to require certification of the refrigerant used to determine
the represented values for a basic model. By combining these
provisions, a set of represented values will be determined for a given
basic model based on the least-efficient outdoor unit (and, therefore,
as discussed, the least-efficient refrigerant), and the refrigerant
must be certified by the manufacturer. Therefore, DOE is not adopting
the CA IOUs' suggestions to allow certification of multiple
refrigerants, because it would be inconsistent with the Department's
adopted requirement that the represented values for a basic model be
based on the least-efficient outdoor unit. Correspondingly, because DOE
is not adopting the CA IOU's suggestion to allow certification of
multiple refrigerants, DOE has concluded that requiring certification
of the associated refrigerant characteristics (i.e., GWP) would provide
minimal benefit, as there will not be ratings for different
refrigerants within a basic model to compare. Therefore, DOE has
concluded that requiring certification of refrigerant GWP would be
unnecessarily burdensome.
DOE is adopting all other proposals related to certification
reporting requirements, without change. As discussed, these amended
certification reporting requirements are not required until the
compliance date of amended energy conservation standards for VRF multi-
split systems denominated in terms of IEER, should DOE adopt such
standards.
b. Supplemental Testing Instructions
The December 2021 VRF TP NOPR included proposals to amend the STI
provisions at 10 CFR 429.43(b)(4) to reflect the proposed amendments to
the test procedure and the proposed adoption of the IEER metric. 86 FR
70644, 70666 (Dec. 10, 2021). DOE proposed amendments and additions to
the STI requirements as follows:
<bullet> Identification of the indoor units to be thermally active
for each IEER test point;
<bullet> The rated indoor airflow for the full-load cooling, full-
load heating, and all part-load cooling tests (for each indoor unit),
in standard cubic feet per minute (scfm);
<bullet> The indoor airflow-control setting to be used in the full-
load cooling test and the indoor airflow control setting to be used in
the full-load heating test (for each indoor unit);
<bullet> For water-cooled units, the rated water flow rate in
gallons per minute (gpm);
<bullet> System start-up or initialization procedures, including
conditions and durations;
<bullet> The duration of the compressor break-in period. (Existing
requirements in 10 CFR 431.96(c) require manufacturers to include this
information in the test data underlying the certified ratings that must
be maintained according to 10 CFR 429.71);
<bullet> Instructions for adjustment of critical parameters to meet
capacity targets and/or SHR limits, including hierarchy for adjusting;
<bullet> The layout of the system set-up for testing (previously
required upon request) including a piping diagram, set-up instructions
for indoor units and outdoor units, charging instructions, a control
wiring diagram, and

[[Page 63881]]

identification of the location of each critical parameter;
<bullet> Explicitly providing that the nominal cooling capacity and
nominal heating capacity (if applicable) in British thermal units per
hour (Btu/h) must be certified for each outdoor unit and indoor unit;
<bullet> Requiring testing instructions for conducting testing for
all indoor unit combinations with distinct represented values within a
basic model, as applicable;
<bullet> Removing the current requirement to report compressor
frequency setpoints and instead require reporting operational settings
for all critical parameters to be manually controlled for each of the
four IEER cooling test conditions and for the COP heating test;
<bullet> Removing the reporting requirement regarding whether the
model will operate at test conditions without manufacturer programming
because the VRF enforcement provisions allow for a manufacturer
representative to be on site for DOE testing;
<bullet> Removing the reporting requirement for rated static
pressure, which is unnecessary because AHRI 1230-2021 includes ESP
requirements for testing; and
<bullet> The frequency of oil-recovery cycles.
Further, in the December 2021 VRF TP NOPR, DOE proposed at 10 CFR
429.43(b)(4) a certification reporting requirement for supplemental
test instructions for VRF multi-split systems regarding specific
components, corresponding to the proposed representation requirements
for specific components at 10 CFR 429.43(a)(4). Specifically, DOE
proposed that the manufacturer must certify in the STI for which, if
any, specific components (as listed in 10 CFR 429.43(a)(4)(i)) the
following provisions are applicable: (1) the indoor unit model(s) in a
tested combination within a basic model include both individual indoor
unit models distributed in commerce with the specific component and
individual indoor unit models distributed in commerce without the
specific component; (2) at least one of the individual indoor unit
models distributed in commerce without the specific component is
otherwise identical to any given individual indoor unit model
distributed in commerce with the specific component; and (3)
represented values for the tested combination are based on performance
of individual indoor unit models distributed in commerce without the
specific component. 86 FR 70644, 70666-70667 (Dec. 10, 2021). These
proposed provisions would require manufacturers to report whether the
represented values for that VRF multi-split system basic model were
determined based on the presence or absence of air economizers and/or
desiccant dehumidification components.
In commenting on DOE's proposals in this area, AHRI and Carrier
stated that STI requirements may need to include provisions that
specify which, if any, components were used when calculating efficiency
ratings. (AHRI, No. 12 at p. 2; Carrier, No. 7 at p. 1)
In response and as described in section III.G.1.c.iii of this
document, DOE is finalizing an approach in this rule requiring that if
an indoor unit model number is not fully specified in the public
certification, then represented values must be determined from a fully-
specified individual indoor unit model distributed in commerce that
must be consistent with the certified indoor unit model number (i.e.,
all specified digits must match). Among the group of all indoor unit
models having a consistent model number, that VRF system must have the
least number (which may include zero) of specific components installed.
Because the representation requirements adopted in this final rule
provide clear direction as to how to determine represented values for
basic models that include specific components, DOE concludes that a
certification requirement for manufacturers to report whether
representations are based on model(s) with specific components
installed would be duplicative and would impose unnecessary burden on
manufacturers. Therefore, DOE is not adopting any certification
requirements related to specific components in this final rule.
DOE also proposed to require reporting as part of the STI the
following manufacturer-specified input conditions for conducting a CVP
at each of the four IEER cooling test conditions:
[squ] The required thermostat setpoints to ensure control for 80
[deg]F dry-bulb temperature when accounting for setpoint bias;
[squ] The starting indoor dry-bulb temperature; and
[squ] The indoor dry-bulb temperature ramp rate.

Id.
The CA IOUs commented that the system controls setting for steady-
state tests should be included in the STI requirements. Specifically,
the CA IOUs suggested expanding the requirement for the ``required dip
switch/control settings for step or variable components'' to instead
require ``Dip switch/Control Settings from the manufacturer's
installation instructions used for the full-load cooling and full-load
heating tests.'' The CA IOUs asserted that this change would reduce the
test burden when determining which control setting to use for the CVP
as part of enforcement testing. (CA IOUs, No. 11 at p. 4) AHRI
commented that some certification reporting requirements, such as
compressor speed, critical parameter settings, and system device
required for testing, are confidential business information and that
they should be designated as such for certification. AHRI elaborated on
this point by stating that the information included in the STI is
confidential and should be designated as such. (AHRI, No. 12 at pp. 6-
7) Similarly, Daikin commented that they support DOE's proposal for
certification reporting requirements, provided that all confidential
information may be submitted in the STI, because the STI is not
available to the public. (Daikin, No. 13 at p. 5)
With respect to the CA IOU's request to amend the language of STI
reporting requirements for dip switch/control settings, DOE interprets
this suggestion to mean that manufacturers would be required to specify
all dip switch/control settings required for conducting the full-load
cooling and heating tests. This would include all settings for ``step
or variable components'' in addition to any other settings required for
testing that are not otherwise dictated by the test procedure but may
impact system behavior--for example, ``mode-type'' settings (e.g., eco-
mode) or settings related to another function (e.g., noise reduction
settings). DOE finds that the CA IOUs' proposal would improve the
clarity of existing certification requirements, as it would ensure that
the control settings needed for testing are readily identifiable and
that they are used in a consistent manner during testing. Further, DOE
finds that the CA IOUs' suggestion would not require additional
collection of information by manufacturers, because the settings used
for conducting testing would be readily available to manufacturers.
Therefore, DOE is adopting the STI certification requirements for VRF
multi-split systems as proposed in the December 2021 VRF TP NOPR, with
the clarification that certification of dip switch/control settings
applies more broadly than just step/variable components. As discussed
previously, these amended STI certification requirements are not
required until the compliance date of amended energy conservation
standards denominated in

[[Page 63882]]

terms of IEER, should DOE adopt such standards.
With respect to AHRI and Daikin's comments, DOE notes that
certification reports routinely include both public and non-public
information. Specifically, 10 CFR 429.43(b)(2) specifies requirements
for public equipment-specific information, and 10 CFR 429.43(b)(3) and
(4) specify requirements for equipment-specific information and
supplemental information that are non-public. DOE notes that the
treatment of confidential business information is addressed pursuant to
the regulations at 10 CFR 1004.11. Any person submitting information
that they believe to be confidential and exempt by law from public
disclosure should submit via two well-marked copies: one copy of the
document marked ``confidential'' including all the information believed
to be confidential, and one copy of the document marked ``non-
confidential'' with the information believed to be confidential
deleted. While DOE is responsible for making the final determination
with regard to the disclosure or nondisclosure of information contained
in requested documents, DOE will consider the submitter's views in
making its determination. 10 CFR 1004.11(a). Accordingly, in light of
the existing framework for handling confidential business information,
DOE does not find it necessary to adopt the additional measures
suggested by AHRI and Daikin. For the reasons stated in the December
2021 VRF TP NOPR and the paragraphs here, DOE is adopting its proposed
amendments related to the supplemental testing instructions for VRF
multi-split systems along with the previously discussed modifications
suggested by the CA IOUs.
3. Models Required for AEDM Validation
In the December 2021 VRF TP NOPR, DOE proposed that the
manufacturer must validate an AEDM used to make representations for
only a single type of indoor unit combination (i.e., ducted, non-
ducted, or SDHV indoor unit combinations) within or across all its
basic models by testing at least a single tested combination of that
type of indoor unit combination for each of the two selected basic
models. 86 FR 70644, 70667 (Dec. 10, 2021). If a manufacturer makes
representations for two types of indoor unit combinations (i.e.,
ducted, non-ducted, and/or SDHV indoor unit combinations) within or
across all its basic models to which the AEDM applies, DOE proposed
that the manufacturer must test at least: (1) a single tested
combination of a selected basic model as the first of those two types
of indoor unit combination, and (2) a single tested combination of a
different selected basic model as the second of those two types of
indoor unit combination. Id. If a manufacturer makes representations
for all three types of indoor unit combinations (i.e., ducted, non-
ducted, and SDHV indoor unit combinations) within or across all its
basic models to which the AEDM applies, DOE proposed that the
manufacturer must test at least a single tested combination of a
selected basic model as a non-ducted tested combination and a single
tested combination of a different selected basic model as a ducted
tested combination. Id.
In response, AHRI and Daikin commented in support of DOE's proposal
to amend the applicable requirements for AEDM validation. (AHRI, No. 12
at p. 7; Daikin, No. 13 at p. 5) DOE received no other comments on its
AEDM proposals.
Accordingly, DOE is finalizing its proposed AEDM validation
requirements for VRF multi-split systems in 10 CFR 429.43(a)(2) and 10
CFR 429.70 to be similar to the sampling plan requirements for tested
units, as discussed in section III.G.7 of this final rule. Furthermore,
DOE has concluded that these AEDM validation requirements are
consistent with AHRI 1230-2021, because they ensure the values
developed with an AEDM conform to the results obtained using AHRI 1230-
2021.
4. Manufacturer Involvement
a. Role of Manufacturer Representative
In light of the complexity of VRF multi-split systems, the DOE test
procedure at 10 CFR 431.96(f) does allow for limited manufacturer
involvement, specifying that a manufacturer's representative is allowed
to witness assessment and/or enforcement testing, inspect and discuss
set-up only with a DOE representative, and adjust only the modulating
components in the presence of a DOE representative that are necessary
to achieve steady-state operation. In the December 2021 VRF TP NOPR,
DOE proposed to establish new provisions for manufacturer involvement
as part of the product-specific enforcement provisions at 10 CFR
429.134(s)(2). 86 FR 70644, 70667 (Dec. 10, 2021). The proposals
largely align with Sections 5.1.2 and 6.3.3 of AHRI 1230-2021 but
prescribe more precisely the actions that a manufacturer's
representative may take. Specifically, DOE proposed that a
manufacturer's representative is allowed to support commissioning of
the VRF multi-split system and to witness DOE assessment or enforcement
testing. Id at 86 FR 70667-70668. For all cooling and heating tests,
DOE proposed that all control settings other than critical parameters
must be set by a member of the third-party laboratory, and that a
manufacturer's representative may initially set all critical parameters
to their certified values. Id. at 86 FR 70668. For IEER cooling tests
only, DOE proposed to specify that if additional adjustments to
critical parameters are required for meeting capacity targets and/or
SHR limits, a manufacturer's representative may make such adjustments
in accordance with section 5.1 of appendix D1 using a proprietary
control tool. Id. DOE further proposed that initial setting and any
additional critical parameter adjustments performed by a manufacturer's
representative during IEER testing must be monitored by third-party
laboratory personnel using a service tool. Id. For the heating test,
DOE proposed that the manufacturer's representative would not be
permitted to make any critical parameter adjustments during testing and
would only be allowed to initially set critical parameters to their
certified values. Id.
The CA IOUs, Joint Advocates, and Lennox commented that they
support DOE's proposal to specify the parameters of manufacturer
involvement during testing. (CA IOUs, No. 11 at p. 3; Joint Advocates,
No. 9 at p. 1; Lennox, No. 8 at p. 3) Joint Advocates further asserted
that the language in Sections 5.1.2 and 6.3.3 of AHRI 1230-2021 is
ambiguous, and that DOE's proposed language clarifies the role of the
manufacturer's representative during testing. (Joint Advocates, No. 9
at p. 1) The CA IOUs stated that DOE's proposals strike a reasonable
balance between ensuring objective/repeatable ratings and the
complexity associated with testing VRF multi-split systems. (CA IOUs,
No. 11 at p. 3)
AHRI commented that, due to the need for proprietary software, a
manufacturer's representative, if present, should set the control
settings, observed by a member of the third-party lab. They elaborated
that a member of a third-party laboratory should set the critical
parameters in the case where a manufacturer's representative is unable
to be physically available or is choosing not to be present. AHRI
further commented that they agree with DOE's proposals with respect to
manufacturer involvement for cooling tests but argued that the
manufacturer's representative should also be allowed to adjust the

[[Page 63883]]

critical parameters for heating tests (similar to IEER cooling tests).
(AHRI, No. 12 at pp. 7-8) Specifically, AHRI argued that just as
critical parameter adjustments are needed for cooling tests to meet
capacity targets and/or SHR limits, small adjustments to critical
parameters may be needed during heating tests to account for set-up
variations between manufacturer and third-party laboratories. Further,
AHRI asserted that on this topic, there is a conflict between the
language proposed in the preamble and the proposed regulatory text of
the December 2021 VRF TP NOPR, so further clarification is needed. The
commenter referenced language from the NOPR's preamble (86 FR 70644,
70668 (Dec. 10, 2021)) stating that a manufacturer's representative may
not make critical parameter adjustments during heating tests, and would
only be allowed to initially set critical parameters to their certified
values. AHRI contrasted this with language in the proposed regulatory
text at 10 CFR 429.134(s)(2)(ii) that would allow the manufacturer's
representative to adjust the critical parameters for heating and IEER
cooling tests (86 FR 70644, 70681 (Dec. 10, 2021)). (AHRI, No. 12 at
pp. 7-8)
Regarding AHRI's request that a manufacturer's representative
should set the control settings rather than a member of the third-party
laboratory, DOE interprets this request to refer to control settings
other than the critical parameter settings (e.g., airflow control
settings) because, as discussed, DOE proposed that the manufacturer's
representative would set critical parameter settings to their certified
values. DOE finds that requiring a member of the laboratory to set
other control settings rather than a manufacturer's representative will
improve transparency into testing practices by ensuring that settings
used for testing match the settings specified in the manufacturer STI.
Also, AHRI's suggestion conflicts with the language present in AHRI
1230-2021 regarding control settings other than critical parameters.
Specifically, Section 5.1.2.3 of AHRI 1230-2021 states that ``control
settings shall be set by a member of the laboratory. All control
settings are to remain unchanged for all load points once system set up
has been completed.'' DOE's proposed approach (i.e., requiring that all
control settings other than critical parameters be set by a member of
the third-party laboratory) is consistent with the language from
Section 5.1.2.3 of AHRI 1230-2021, which DOE understands to reflect the
industry consensus approach and the intent of the Working Group.
DOE interprets AHRI's concern about ``proprietary software'' to
suggest that a member of the third-party laboratory should not be
allowed to interact with such software. DOE finds that the use of
proprietary software is not a valid reason to preclude involvement of
third-party laboratory personnel during testing. Per DOE's proposal, a
manufacturer's representative would be allowed to support commissioning
of the VRF multi-split system to ensure that any proprietary software
is being properly utilized by a member of the third-party laboratory.
The amended STI certification requirements (described in section
III.G.2.b of this document) ensure that members of the third-party
laboratory will be equipped with all necessary information in order to
set control settings during testing. If a manufacturer's representative
is not available for testing, then testing would proceed with a member
of the third-party laboratory using the control tool as provided by the
manufacturer (see discussion in section III.G.4.b of this document)--an
approach which was similarly suggested by AHRI in their comment. (AHRI,
No. 12 at p. 8) Therefore, DOE is finalizing its proposal to require
that members of the third-party laboratory set all control settings
(other than critical parameters) during testing.
With regard to AHRI's argument for allowing critical parameter
adjustments for heating tests, the cooling capacity targets and SHR
limits specified in Section 6.3.3 of AHRI 1230-2021 and Section 5.2 of
the proposed test procedure in appendix D1 do not apply to heating
tests, and neither DOE's proposed test procedure nor AHRI 1230-2021
include any restrictions for heating tests that would warrant critical
parameter adjustments. Further, DOE disagrees with AHRI's claim that
critical parameter adjustments are needed for heating tests to account
for set-up variation between manufacturer and third-party laboratories.
DOE concludes that the STI provides manufacturers sufficient
opportunity to certify critical parameters, control settings, and any
additional testing information needed for the third-party laboratories
to consistently test VRF multi-split systems. Therefore, DOE finds that
allowing for critical parameter adjustments during heating tests is
unnecessary and is inconsistent with the industry consensus test
procedure recommended by the Working Group.
Regarding AHRI's claim of contradictory language, the language in
10 CFR 429.134(s)(2)(ii) proposed in the December 2021 VRF TP NOPR
states, in relevant part, the following under a heading of
``Manufacturer involvement in heating tests and IEER cooling tests'':
``Critical parameters may be manually controlled by a manufacturer's
representative, including initial setting to the certified values and
additional adjustments (as described in sections 5.1 and 5.2 of
appendix D1 to subpart F of part 431, respectively).'' 86 FR 70644,
70681 (Dec. 10, 2021). Neither section 5.1 nor section 5.2 include any
provisions allowing critical parameter adjustments during heating
tests. Specifically, section 5.1 of proposed appendix D1 specifies
provisions for initially setting control settings applicable for
cooling and heating tests, and section 5.2 specifies provisions for
allowable critical parameter adjustments that apply only for IEER
cooling tests. Because the phrasing in proposed 10 CFR
429.134(s)(2)(ii) allows critical parameter adjustments as described in
sections 5.1 and 5.2 of appendix D1, which do not allow for critical
parameter adjustments during heating tests, DOE concludes that the
proposed regulatory text is consistent with the preamble discussion
highlighted by AHRI (86 FR 70644, 70668 (Dec. 10, 2021)). However, DOE
recognizes the potential to improve the clarity of the regulatory text
regarding the specific adjustments that can be made by a manufacturer
representative.
Accordingly, in this final rule DOE is adopting the proposed
provisions for manufacturer involvement as part of product-specific
enforcement provisions at 10 CFR 429.134(v)(2). However, in light of
the confusion reflected in AHRI's comment, DOE is adopting language in
10 CFR 429.134(v)(2) that clarifies that critical parameter adjustments
apply only to IEER cooling tests, not to heating tests.
b. Control Tool
In the case that a manufacturer is not present for assessment or
enforcement testing, third-party laboratory personnel may need a
manufacturer's control tool to set critical parameters to the initial
settings or make additional adjustments required by the test procedure.
In the December 2021 VRF TP NOPR, DOE proposed to amend its enforcement
test notice requirements for VRF multi-split systems at 10 CFR
429.110(b)(1)(iv) to require manufacturers to include a means of
control to set and adjust critical parameters with all systems provided
for enforcement testing. 86 FR 70644, 70668 (Dec. 10, 2021).
Correspondingly, DOE proposed provisions for VRF multi-split systems at
10 CFR 429.104(b) that would require

[[Page 63884]]

manufacturers to provide a means of control for assessment testing,
although manufacturers would not be required to provide the VRF multi-
split system for assessment testing. Id. This proposal would enable the
laboratory staff to perform IEER and heating tests in the event that a
manufacturer's representative is not available for assessment and/or
enforcement testing. Id. DOE also proposed that, if a manufacturer's
representative is not present for testing, a member of the third-party
laboratory shall set and adjust critical parameter values in accordance
with section 5.1 of appendix D1 using the means of control provided by
the manufacturer in response to the test notice. Id.
AHRI commented that the means of control of the unit could not be
shipped ``from a retailer or distributor'' because it is not sold with
the unit and, therefore, not sold by a distributor. They further
commented that the means of control would need to be provided by the
manufacturer, and preferably by the manufacturer's representative due
to confidentiality. They suggested the following language: ``If a
manufacturer's representative is not present for testing, a member of
the third-party laboratory must set and adjust critical parameters
using the provided means of control described in Sec.
429.110(b)(1)(iv) for enforcement testing.'' (AHRI, No. 12 at pp. 7-8)
Daikin commented that DOE's proposal regarding manufacturer
involvement during assessment and enforcement testing is acceptable,
provided that, should testing be scheduled and then delayed due to
unforeseen circumstances (e.g., travel issues, positive COVID-19
tests), the provision stating ``If a manufacturer's representative is
not present for testing, a member of the third-party laboratory must
set and adjust critical parameters . . .'' would not be invoked, but
rather the testing would be rescheduled. Daikin further commented that
a means of control for running the CVP would not be sold by retailers
or distributors, as it contains confidential company intellectual
property. Daikin suggested regulatory text that would require the
manufacturer to ship any means of control necessary for conducting
testing, if requested by DOE. Daikin also suggested language specifying
that the means of control may be provided separately from the system(s)
selected for testing, stating that it is not appropriate to ship the
controls tool (usually a laptop) along with the VRF equipment via less
than truckload (LTL) freight shipping. (Daikin, No. 13 at pp. 5-6)
With regard to the logistics around sending manufacturer control
tools, DOE acknowledges the comments from AHRI and Daikin indicating
that means of control are not typically provided with a VRF multi-split
system and would, therefore, not come from a retailer or distributor,
but directly from the manufacturer, and potentially separate from the
VRF equipment itself. Consequently, DOE is adopting the proposed
provisions at 10 CFR 429.104(b) and 10 CFR 429.110(b)(1)(iv) with
modifications to specify that, while manufacturers must provide a means
of control for assessment testing, the means of control (necessary for
testing conducted in accordance with appendix D1) may be shipped
directly from the manufacturer, and separately from the system(s)
selected for testing. These revisions are consistent with the language
proposed by Daikin in their comment.
With regard to Daikin's suggestion that enforcement testing be
rescheduled if the manufacturer is unable to attend due to ``unforeseen
circumstances,'' DOE will consider such circumstances as they arise on
a case-by-case basis, and the Department will balance between providing
reasonable flexibility and maintaining the integrity of the enforcement
program. With regard to AHRI's suggestion that if a manufacturer's
representative is not present for testing, a member of the third-party
laboratory must set and adjust critical parameters using the provided
means of control. DOE finds that this suggestion is already consistent
with the proposed provisions covering manufacturer involvement and with
the discussion in this section. In consideration of all input received
on this topic, DOE is adopting its proposed provisions at 10 CFR
429.104, 10 CFR 429.110, and 10 CFR 429.134 as proposed, with the
additional clarifications previously discussed in this section.
5. Break-In Period
The current Federal test procedure for VRF multi-split systems
specifies at 10 CFR 431.96(c) that manufacturers may optionally specify
a ``break-in'' period, not to exceed 20 hours, to operate the equipment
under test prior to conducting the test method specified in by AHRI
1230-2010. In the December 2021 VRF TP NOPR, DOE proposed to include
similar provisions for VRF multi-split systems, but as part of the STI
certification requirements rather than the proposed test procedure. 86
FR 70644, 70666 (Dec. 10, 2021). DOE did not receive any comments in
response to this proposal.
However, DOE inadvertently omitted the 20-hour maximum time period
from the proposed STI certification requirements. A 20-hour maximum
time period prevents DOE testing from being unduly burdensome and is
consistent with the current Federal test procedures for VRF multi-split
systems as well as numerous other categories of air conditioners and
heat pumps, including three-phase CUAC/HPs with cooling capacity less
than 65,000 Btu/h, single package vertical units, computer room air
conditioners, and central air conditioners and heat pumps. Therefore,
DOE concludes that a 20-hour limit on the specified break-in period
should also apply to testing VRF multi-split systems according to
Appendix D1.
As such, for the reasons previously stated, DOE is specifying in 10
CFR 429.43(b)(4) that a manufacturer may certify a compressor break-in
period duration of 20 hours or less in its STI. Further, DOE is adding
a clarifying provision at 10 CFR 429.134(v)(4) stating that, during
assessment and enforcement testing, DOE will perform a break-in period
on VRF multi-split systems using a duration specified by the
manufacturer only if a break-in period duration is specified in the
STI.
6. Certified Critical Parameter Operational Settings
DOE proposed in the December 2021 VRF TP NOPR to add a
certification reporting provision specific to VRF multi-split systems
in 10 CFR 429.43(b)(5) stating 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 re-certify the operational
settings of those critical parameters for all affected basic models, as
well as re-rate and re-certify the affected basic models. 86 FR 70644,
70668 (Dec. 10, 2021). DOE also proposed to amend the enforcement
testing requirements at 10 CFR 429.110(a) to state that DOE may
initiate enforcement testing for VRF multi-split systems if DOE has
reason to believe that the model is not in compliance, has invalid
certified operational settings for critical parameter values, or has an
otherwise invalid certified rating. Id. at 86 FR 70669.
Joint Advocates commented that DOE should provide additional
clarification in the case when a manufacturer becomes aware that their
certified critical parameter values have been invalidated, and these
commenters

[[Page 63885]]

specifically suggested that DOE should specify a timeline between
becoming aware of the invalid parameters and recertifying the impacted
models. (Joint Advocates, No. 9 at p. 2) The CA IOUs commented that
they support DOE's proposal for evaluating compliance of a system whose
STI-reported critical parameters have been invalidated. (CA IOUs, No.
11 at p. 2) AHRI commented that in the context of a ``another party''
(i.e., other than DOE) conducting a CVP that results in invalidated
operational settings for critical parameters for a basic model, DOE
should clarify that ``another party'' should not be a competitor,
university, or party other than DOE. They commented that only DOE, a
third-party lab contracted by DOE, or AHRI should have access to the
STI. Further, they commented that if ``another party'' becomes aware of
a potential issue, an investigation should take place rather than
enforcement action. (AHRI, No. 12 at p. 8)
In response, regarding the comments received from the Joint
Advocates and AHRI about DOE's procedures for recertification and for
initiating enforcement testing, DOE notes that these procedures pertain
to DOE enforcement testing policy more generally, not just to VRF
multi-split systems. Under 10 CFR 429.102(a)(8), it is a prohibited act
for a manufacturer or private labeler to knowingly misrepresent the
efficiency rating of any covered product or covered equipment
distributed in commerce in a manner that is not supported by test data
(e.g., a manufacturer determines IEER rating based on certified
critical parameter values which are later invalidated via a CVP). For
any other regulated product types, DOE does not specify in regulations
a required timeline for recertification or any constraints on the
information sources that DOE may consider as part of an enforcement
case. For other categories of regulated air conditioners and heat pumps
for which similar proprietary information may be included in STI or
non-public sections of certification reports, the treatment of any
proprietary aspects of the certification materials has been adequately
addressed under the existing enforcement regulations without any
product-specific restrictions. Therefore, while DOE acknowledges AHRI's
concern that the critical parameter settings necessary for testing
contain sensitive information, DOE has concluded that VRF multi-split
systems do not warrant additional product-specific restrictions to the
existing enforcement regulations. Therefore, DOE is not adopting a
timeline regarding re-certification or defining which entities are able
to submit information that may instigate potential enforcement action
for VRF multi-split systems in this final rule. DOE will consider any
appropriately submitted information in its assessment of compliance on
a case-by-case basis. Based on the discussion presented in the December
2021 VRF TP NOPR and in the preceding paragraphs, DOE is adopting the
provisions as proposed in the NOPR regarding the CCE process in the
event that certified critical parameter operational settings have been
invalidated by a CVP. This process is visually represented in Figure 1
in section II of this document.
7. Enforcement Sampling Plan
The enforcement sampling plan for VRF multi-split systems was last
amended in a final rule published in the Federal Register on March 7,
2011, which addressed certification, compliance, and enforcement for
consumer products and commercial and industrial equipment. 76 FR 12422
(``March 2011 CCE Final Rule''). In the March 2011 CCE Final Rule, DOE
specified flexible sampling provisions for certain covered products and
equipment for which there is a lower market volume and/or manufacturing
tends to be more customized. 76 FR 12422, 12436 (March 7, 2011). DOE
included among such covered equipment commercial heating, air-
conditioning, and ventilation equipment, which includes VRF multi-split
systems. Id. As established by the March 2011 CCE Final Rule, 10 CFR
429.110(e)(2) states that for commercial air conditioners and heat
pumps (which includes VRF multi-split systems), DOE will use an initial
sample size of not more than four units when determining a basic
model's compliance with applicable energy conservation standards.
In the December 2021 VRF TP NOPR, DOE proposed to amend its
enforcement sampling plan requirements specific to VRF multi-split
systems to require a sample size of two VRF multi-split systems. DOE
proposed a reduced sample size to reflect what the Department considers
to be an adequate sample size for assessment and enforcement testing
but that also recognizes of the involved nature of testing VRF multi-
split systems. DOE did not propose to amend the process for determining
compliance with energy conservation standards (i.e., the compliance
determination would be made for VRF multi-split systems using the
sampling plan found in appendix B to subpart C of part 429 with a first
sample size of n<INF>1</INF> = 2). 86 FR 70644, 70669 (Dec. 10, 2021).
The Joint Advocates commented that they support DOE's proposed
sampling plan, due to the complexity of the test procedure
commissioning for VRF equipment. (Joint Advocates, No. 9 at p. 2).
Daikin agreed that the cost burden of testing VRF multi-split systems
is high, including the equipment itself, copper piping, refrigerant,
and laboratory testing. (Daikin, No. 13 at p. 6)
However, Daikin expressed concern with using a sample size of two
combined with the sampling plan found in appendix B to subpart C of
part 429. Specifically, Daikin worried that the sample size of only two
units would be unlikely to produce a sample mean and standard deviation
that match the population mean and standard deviation. Daikin provided
examples illustrating that a two-unit sample with lower and more varied
test results could be determined compliant with the standard (e.g.,
first sample testing at 16.1 and the second sample testing at 15.5
would be considered to meet a 17 IEER standard), while a different two-
unit sample with higher and less varied test results could be
determined non-compliant (e.g., first sample testing at 16.1 and the
second sample testing at 16.2 would be considered to fail to meet a 17
IEER standard). Daikin concluded by asserting that it is not
impractical, due to inherent statistics, to test four samples for
enforcement. (Daikin, No. 13 at p. 6) AHRI commented that while costs
associated with procurement of VRF multi-split systems may be high,
there is not sufficient technical justification to deviate from the
four-unit sample used for enforcement testing. AHRI stated that using a
statistical sample to develop testing is an important feature of DOE's
enforcement program. (AHRI, No. 12 at p. 9)
DOE recognizes the concerns from AHRI and Daikin regarding the
proposed reduced enforcement sampling plan for VRF multi-split systems.
In particular, DOE acknowledges Daikin's comments that modifying the
regulations to specify a two-system enforcement sample with the
existing sampling plan at appendix B to subpart C of part 429 could
result in further variation between the sample standard deviation and
the population standard deviation. Therefore, DOE is not amending the
enforcement sampling plan for VRF multi-split systems at 10 CFR
429.110(e)(2) as proposed, which would have reduced the required sample
size from four units to two units. Figure 1 in section II of this
document reflects this determination.

[[Page 63886]]

Although DOE is not amending the enforcement sampling plan for VRF
multi-split systems in this final rule, DOE notes that stakeholder
comments agreed with DOE's position in the December 2021 VRF TP NOPR
that the burden associated with testing VRF multi-split systems is
significantly higher than for other types of commercial HVAC equipment.
In the March 2011 CCE Final Rule, DOE established an initial sample
size of four units for this equipment and included provisions that
provides for testing of fewer than four units if they are unavailable
at the time that the test notice is received. 10 CFR 429.110(e)(3). The
enforcement provisions also include a general provision applicable to
all covered products and equipment that states if testing of the
available or subsequently available units of a basic model would be
impractical, as for example when a basic model has unusual testing
requirements or has limited production, DOE may in its discretion
decide to base the determination of compliance on the testing of fewer
than the otherwise required number of units. 10 CFR 429.110(e)(7). DOE
explained in the March 2011 CCE Final Rule that it would, in its
evaluation of testing availability, take into consideration the units
themselves as well as availability of third-party testing facilities to
run the DOE test procedure. 76 FR 12422, 12436 (March 7, 2011).
8. Certified vs. Tested Performance
In the December 2021 VRF TP NOPR, DOE proposed a process for
assessment and enforcement testing for VRF multi-split systems to
incorporate the CVP, which was illustrated via a flowchart in Figure 1
of that NOPR (repeated here as Figure 2). 86 FR 70644, 70662 (Dec. 10,
2021). One of the paths in the diagram showed that if a system was
tested for IEER and was determined to be in compliance with the Federal
standards, but did not meet the certified IEER value, then it would
constitute an improper certification and manufacturers would be
required to re-rate and recertify that model.
[GRAPHIC] [TIFF OMITTED] TR20OC22.001

Daikin commented that this figure illustrates that regardless of
whether a CVP is performed, the basic model must be re-rated if the
IEER testing results are deemed invalid. Daikin asserted that the
proposed regulatory text did not indicate that if critical parameters
are validated but the IEER is not validated then a re-rate is required,
as indicated in the figure. (Daikin, No. 13 at p. 7)
AHRI asserted that DOE's proposal would introduce a tolerance on
the certified IEER and claimed that DOE's proposal for certified IEER
to be within any tolerance of the rated IEER would create a more
stringent requirement for VRF equipment than for other Federally-
regulated products. AHRI further asserted that verification of
published ratings is the purpose of the AHRI certification program, and
that DOE's enforcement authority is to ensure compliance with energy
conservation standards. However, AHRI acknowledged DOE's enforcement
authority under 10 CFR 429.102(a)(8), 10 CFR 429.102(b), and 10 CFR
429.106(a), and further recognized that 10 CFR 429.114(b) provides that
DOE may issue a notice of noncompliance determination in the event that
the Department determines a manufacturer has failed to comply with an
applicable certification requirement with respect to a particular basic
model. However, AHRI argued that besides DOE's

[[Page 63887]]

regulations for application of an AEDM at 10 CFR 429.70,\30\ there are
no other references to or requirements surrounding the accuracy of
certified ratings in subpart B--Certification. (AHRI, No. 12 at p. 9)
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