[Federal Register Volume 88, Number 224 (Wednesday, November 22, 2023)]
[Notices]
[Pages 81385-81396]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-25873]


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DEPARTMENT OF ENERGY

[Case Number 2022-004; EERE-2022-BT-WAV-0010]


Energy Conservation Program: Decision and Order Granting a Waiver 
to Norlake, Inc., dba Refrigerated Solutions Group, From the Department 
of Energy Walk-In Coolers and Walk-In Freezers Test Procedure

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

ACTION: Notification of decision and order.

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SUMMARY: The U.S. Department of Energy (``DOE'') gives notification of 
a Decision and Order (Case Number 2022-004) that grants to Norlake, 
Inc., dba Refrigerated Solutions Group (``RSG'') a waiver from 
specified portions of the DOE test procedure for determining the energy 
efficiency of specified walk-in cooler refrigeration systems. Under the 
Decision and Order, RSG is required to test and rate the specified 
basic models of its equipment in accordance with the alternate test 
procedure set forth in the Decision and Order.

DATES: The Decision and Order is effective on November 22, 2023. The 
Decision and Order will terminate upon the date on which use of the 
test procedure for walk-in coolers and walk-in freezers located at 
title 10 of the Code of Federal Regulations (``CFR''), part 431, 
subpart R, appendix C1 is required to determine compliance with energy 
conservation standards. At such time, RSG must use the relevant test 
procedure for this equipment for any testing to demonstrate compliance 
with the applicable standards, and any other representations of energy 
use.

FOR FURTHER INFORMATION CONTACT: 
    Ms. Julia Hegarty, U.S. Department of Energy, Office of Energy 
Efficiency and Renewable Energy, Building Technologies Office, Mailstop 
EE-5B, 1000 Independence Avenue SW, Washington, DC 20585-0121. Email: 
[email protected].
    Mr. Matthew Schneider, U.S. Department of Energy, Office of the 
General Counsel, GC-33, 1000 Independence Avenue SW, Washington, DC 
20585-0121. Telephone: (240) 597-6265. Email: [email protected].

SUPPLEMENTARY INFORMATION: In accordance with 10 CFR 431.401(f)(2), DOE 
gives notification of the issuance of its Decision and Order as set 
forth below. The Decision and Order grants RSG a waiver from the 
applicable test procedure at 10 CFR part 431, subpart R, appendix C for 
the specified basic models for which RSG petitioned for waiver and 
provides that RSG must test and rate such equipment using the alternate 
test procedure specified in the Decision and Order. RSG's 
representations concerning the energy efficiency of the specified basic 
models must be based on testing according to the provisions and 
restrictions in the alternate test procedure set forth in the Decision 
and Order, and the representations must fairly disclose the test 
results. Distributors, retailers, and private labelers are held to the 
same requirements when making

[[Page 81386]]

representations regarding the energy efficiency of this equipment. (42 
U.S.C. 6314(d))
    Any manufacturer of a basic model employing a technology or 
characteristic for which a waiver was granted for another basic model 
and that results in the need for a waiver (as specified by DOE in a 
published decision and order in the Federal Register) must petition and 
be granted a waiver for that basic model. (10 CFR 431.401(j)) 
Manufacturers may also submit a request for interim waiver pursuant to 
the requirements of 10 CFR 431.401.

Case 2022-004

Decision and Order

I. Background and Authority

    The Energy Policy and Conservation Act, as amended (``EPCA''),\1\ 
authorizes the U.S. Department of Energy (``DOE'') to regulate the 
energy efficiency of a number of consumer products and certain 
industrial equipment. (42 U.S.C. 6291-6317) Title III, Part C \2\ of 
EPCA established the Energy Conservation Program for Certain Industrial 
Equipment, which sets forth a variety of provisions designed to improve 
the energy efficiency for certain types of industrial equipment. This 
equipment includes walk-in coolers and walk-in freezers (collectively, 
``walk-ins''), the focus of this document. (42 U.S.C. 6311(1)(G))
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    \1\ All references to EPCA in this document refer to the statute 
as amended through the Energy Act of 2020, Public Law 116-260 (Dec. 
27, 2020), 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. 6299).
    The Federal testing requirements consist of test procedures that 
manufacturers of covered equipment must use as the basis for: (1) 
certifying to DOE that their equipment complies with the applicable 
energy conservation standards adopted pursuant to EPCA (42 U.S.C. 
6316(a); 42 U.S.C. 6295(s)), and (2) making representations about the 
efficiency of that equipment (42 U.S.C. 6314(d)). Similarly, DOE must 
use these test procedures to determine whether the equipment complies 
with relevant standards promulgated under EPCA. (42 U.S.C. 6316(a); 42 
U.S.C. 6295(s))
    Under 42 U.S.C. 6314, EPCA sets forth the criteria and procedures 
DOE is required to follow when prescribing or amending test procedures 
for covered equipment. EPCA requires that any test procedures 
prescribed or amended under this section must be reasonably designed to 
produce test results which reflect energy efficiency, energy use or 
estimated annual operating cost of covered equipment during a 
representative average use cycle and requires that test procedures not 
be unduly burdensome to conduct. (42 U.S.C. 6314(a)(2)) The test 
procedures for walk-in refrigeration systems are set forth at 10 CFR 
part 431, subpart R, appendix C, Uniform Test Method for the 
Measurement of Net Capacity and AWEF of Walk-in Cooler and Walk-in 
Freezer Refrigeration Systems (``appendix C'') and appendix C1, Uniform 
Test Method for the Measurement of Net Capacity and AWEF2 of Walk-In 
Cooler and Walk-In Freezer Refrigeration Systems (``appendix C1'').\3\
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    \3\ Appendix C is the test procedure currently required for 
walk-in refrigeration systems to demonstrate compliance with energy 
conservation standards. Use of appendix C1 will be required 
beginning on the compliance date of any amended energy conservation 
standards for walk-ins published after January 1, 2022. DOE has 
established separate test procedures for walk-in envelope components 
at 10 CFR part 431, subpart R, appendices A and B. Appendix A is 
used for testing the energy use of walk-in display panels, display 
doors, and non-display doors; appendix B is used for testing 
insulation R-value of non-display panels and non-display doors.
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    Any interested person may submit a petition for waiver from DOE's 
test procedure requirements. 10 CFR 431.401(a)(1). DOE will grant a 
waiver from the test procedure requirements if DOE determines either 
that the basic model for which the waiver was requested contains a 
design characteristic that prevents testing of the basic model 
according to the prescribed test procedures, or that the prescribed 
test procedures evaluate the basic model in a manner so 
unrepresentative of its true energy consumption characteristics as to 
provide materially inaccurate comparative data. 10 CFR 431.401(f)(2). 
In granting a waiver or interim waiver, DOE will not change the energy 
use or efficiency metric that the manufacturer must use to certify 
compliance with the applicable energy conservation standard and to make 
representations about the energy use or efficiency of the covered 
equipment. 10 CFR 431.401(a). DOE may grant the waiver subject to 
conditions, including adherence to alternate test procedures. 10 CFR 
431.401(f).
    As soon as practicable after the granting of any waiver, DOE will 
publish in the Federal Register a notice of proposed rulemaking to 
amend its regulations so as to eliminate any need for the continuation 
of such waiver. 10 CFR 431.401(l). As soon thereafter as practicable, 
DOE will publish in the Federal Register a final rule to that effect. 
Id. When DOE amends the test procedure to address the issues presented 
in a waiver, the waiver will automatically terminate on the date on 
which use of that test procedure is required to demonstrate compliance. 
10 CFR 431.401(h)(3).

II. RSG's Petition for Waiver: Assertions and Determinations

    On February 17, 2022, DOE received from RSG a petition for waiver 
and interim waiver from the DOE test procedure for walk-in 
refrigeration systems set forth at 10 CFR part 431, subpart R, appendix 
C. (RSG, No. 1, attachment 1, at pp. 1-3 \4\) Pursuant to 10 CFR 
431.401(e)(i), DOE posted the petition on the DOE website. The petition 
did not identify any of the information contained therein as 
confidential business information.
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    \4\ A notation in this form provides a reference for information 
that is in the docket for this test procedure waiver (Docket No. 
EERE-2022-BT-WAV-0010) (available at www.regulations.gov/document/EERE-2022-BT-WAV-0010). This notation indicates that the statement 
preceding the reference is from document number 1 in the docket and 
appears at pages 1-3 of attachment 1 of that document. There are two 
attachments to document 1 of this docket. Attachment 1 is titled 
``DOE Waiver 021722''. Attachment 2 is titled ``RSG DOE Single 
Package System Alternate Test Procedure 021522''.
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    DOE's currently applicable test procedure for walk-in refrigeration 
systems (i.e., appendix C) incorporates by reference Air-Conditioning, 
Heating, and Refrigeration Institute (``AHRI'') Standard 1250-2009, 
2009 Standard for Performance Rating of Walk-In Coolers and Freezers 
(``AHRI 1250-2009''); AHRI Standard 420-2008, Performance Rating of 
Forced-Circulation Free-Delivery Unit Coolers for Refrigeration (``AHRI 
420-2008''); and American Society of Heating, Refrigerating, and Air-
Conditioning Engineers (``ASHRAE'') Standard 23.1-2010, Methods of 
Testing for Rating the Performance of Positive Displacement Refrigerant 
Compressors and Condensing Units that Operate at Subcritical 
Temperatures of the Refrigerant (``ASHRAE 23.1-2010''). AHRI 1250-2009 
is the industry test standard for refrigeration systems for

[[Page 81387]]

walk-in coolers and freezers, including unit coolers and dedicated 
condensing units sold separately, as well as matched pairs. The 
procedure describes the method for measuring the refrigeration capacity 
and the electrical energy consumption for walk-in refrigeration 
systems. Using the refrigeration capacity and electrical energy 
consumption, AHRI 1250-2009 provides a calculation methodology to 
compute AWEF, the applicable energy-performance metric for 
refrigeration systems.
    In its petition for waiver and interim waiver, RSG presented 
several ways in which the currently prescribed test procedure would 
evaluate the specified basic models in a manner so unrepresentative of 
their true energy consumption as to provide materially inaccurate 
comparative data. These issues are summarized below.
    First, as presented in RSG's petition, the specified basic models 
of walk-in refrigeration systems are single-packaged dedicated systems 
that contain multiple refrigeration circuits that operate using a 
single power feed. (RSG, No. 1, attachment 1, at p. 1) RSG claimed that 
the specified basic models meet the definition of a single-packaged 
dedicated system. Id. DOE defines a single-packaged dedicated system as 
``a single-package assembly that includes one or more compressors, a 
condenser, a means for forced circulation of refrigerated air, and 
elements by which heat is transferred from air to refrigerant, without 
any element external to the system imposing resistance to flow of the 
refrigerated air''. See 10 CFR 431.302. As described by RSG, each 
refrigeration circuit in the specified basic models is made up of a 
compressor, expansion, device, condenser, and evaporator. (RSG, No. 1, 
attachment 1, at p. 1) The separate refrigeration circuits may share 
condenser fans, evaporator fans and a control system. Id. In its 
request for waiver and interim waiver, RSG stated that neither appendix 
C nor AHRI 1250-2009 provide a method for testing a single-packaged 
dedicated system with multiple refrigeration circuits. Id.
    Second, RSG stated that the current test procedure requires that 
the unit under test be set up using a 25-foot line-set. Id. Section 3.3 
of appendix C provides the test method for matched systems, single-
packaged dedicated systems, and unit coolers tested alone, which 
references AHRI 1250-2009. Section C5 (Methods of Testing for Walk-In 
Cooler and Freezer Systems that Have Matched Unit Coolers and 
Condensing Units) of AHRI 1250-2009 references test setup requirements 
that include the addition of a line-set that includes either one or two 
mass flow meters. Under section C5 of AHRI 1250-2009, the gross 
refrigeration capacity must be determined either by the dual 
instrumentation refrigerant enthalpy method (section C5.1.1 of AHRI 
1250-2009, Method 1) or by the calibrated box method (section C5.1.2 of 
AHRI 1250-2009, Method 2). Both methods require installation of a 
refrigerant mass flow meter in the system's liquid line to determine 
the cooling capacity. Section C8.3 and Figure C1 of AHRI 1250-2009 
specify the setup and measurements to be conducted for Method 1, for 
which 25-feet of additional refrigerant line is added to connect the 
condenser to the evaporator (unit cooler). Within this 25-foot line, 
two mass flow meters are incorporated, and the heat balance calculated 
from the two flow measurements must be within 5 percent. 
Section C9.2 and Figure C2 of AHRI 1250-2009 specify the setup and 
measurements for Method 2, in which 26-feet of additional refrigerant 
line is added to connect the condenser to the unit cooler (as for 
Method 1), incorporating one mass flow meter. Air-side gross 
refrigeration capacity and refrigerant-side gross refrigeration 
capacity are determined and must be equal to within 5 
percent for the test to be considered valid. The 25 feet and 26 feet 
\5\ of additional liquid line and suction line piping used to set up 
the test is termed a ``line-set''. In its petition for waiver and 
interim waiver, RSG stated that single-packaged dedicated systems are 
not intended to be remotely split via a line-set. (RSG, No. 1, 
attachment 1, at p. 1)
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    \5\ AHRI 1250-2009 does not explain why Method 1 requires 25 
feet of refrigeration line and Method 2 requires 26 feet of 
refrigeration line during test set up.
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    In its request for waiver and interim waiver, RSG noted that DOE 
has issued test procedure waivers for single-packaged dedicated 
refrigeration systems using air enthalpy test methods. (RSG, No. 1, 
attachment 1, at p. 2) DOE granted a waiver to Store It Cold for basic 
models of single-packaged dedicated systems on August 9, 2019. 84 FR 
39286. Store It Cold petitioned for a waiver after determining that the 
dual instrumentation refrigerant enthalpy method specified in AHRI 
1250-2009 was not providing consistent capacity measurements for its 
single-packaged dedicated systems. 84 FR 39286, 39287. The alternate 
test procedure associated with this prior waiver required that the 
specified single-packaged dedicated system basic models shall be tested 
using the Indoor Air Enthalpy Method and the Outdoor Air Enthalpy 
Method in accordance with ASHRAE 37-2009, Methods of Testing for Rating 
Electrically Driven Unitary Air-Conditioning and Heat-Pump Equipment 
(``ASHRAE 37''). 84 FR 39286, 39292. DOE also granted waivers to Air 
Innovations, CellarPro, Vinotemp, and Vinotheque for walk-in 
refrigeration systems used in wine cellar applications, for which some 
of the basic models included in these waivers were single-packaged 
dedicated systems.\6\ The alternate test methods included in these 
waivers require the specified basic models to be tested in accordance 
with AHRI Standard 1250-2020 (2020 Standard for Performance Rating of 
Walk-In Coolers and Freezers, ``AHRI 1250-2020''), which references the 
air enthalpy methods in ASHRAE 37 for testing single-packaged dedicated 
systems.\7\ Use of air enthalpy methods for testing a single-packaged 
dedicated system capture the impact of thermal loss and the 
infiltration of warm air into the evaporator portion of these systems, 
which increases the refrigerant load on the system. In its petition for 
waiver and interim waiver, RSG stated that its laboratory is not set up 
to conduct air enthalpy testing, and that it would require substantial 
time and expense to set up its laboratory to conduct air enthalpy 
testing. (RSG, No. 1, attachment 1, at p. 2) Additionally, RSG 
explained that it contacted third-party labs to inquire about testing 
single-packaged dedicated systems using the air enthalpy method, but 
these labs responded that they are not currently able to conduct air 
enthalpy testing. Id.
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    \6\ See Waiver Decision and Orders for Air Innovations (86 FR 
23702 (May 4, 2021)), CellarPro (86 FR 26496 (May 14, 2021)), 
Vinotheque (86 FR 26504 (May 14, 2021)), and Vinotemp (86 FR 36732 
(Jul. 13, 2021)).
    \7\ Subsequent to DOE's grant of waiver to Store It Cold, AHRI 
published an updated version of AHRI 1250 (i.e., AHRI 1250-2020) 
that provides testing provisions for single-packaged dedicated 
systems that incorporate by reference the approach used in ASHRAE 37 
with some modification.
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    Third, in its request for waiver and interim waiver from the DOE 
test procedure, RSG stated that the current tolerance requirement of 
0.5 [deg]F for the on-coil temperature in section C3.3.3 of AHRI 1250-
2009 is unrealistic. Id. RSG stated that indoor air temperature 
tolerances impact the on-coil temperatures, and that the test procedure 
currently prescribes a 1 [deg]F indoor air temperature test condition 
tolerance.\8\ Id. RSG therefore suggested

[[Page 81388]]

that the on-coil temperature tolerance should also be 1 [deg]F. Id. RSG 
noted further that it can be difficult to repeatedly achieve an on-coil 
temperature tolerance of 0.5 [deg]F when units are shut down, re-
plumbed, and recharged for testing. Id.
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    \8\ Test condition tolerance is the maximum allowed deviation of 
the average of the measurements of a parameter made during a test 
period as compared with its target value. The indoor air dry-bulb 
test condition tolerance is specified as 1 [deg]F in Table 2 of AHRI 
1250-2009.
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    RSG also requested an interim waiver from the existing DOE test 
procedure, explaining that if DOE were to deny its application for 
waiver and interim waiver, it would experience economic hardship in the 
form of lost sales and/or a significant delay in the distribution into 
commerce of the specified basic models. Id.
    On July 22, 2022, DOE published a notification announcing its 
receipt of the petition for waiver and interim waiver and granted RSG 
an interim waiver. 87 FR 43808 (``Interim Waiver Order''). In the 
Interim Waiver Order, DOE initially determined that the alternate test 
procedure--with certain minor modifications as discussed in the Interim 
Waiver Order--appears to allow for the accurate measurement of the 
energy efficiency of the specified basic models, while alleviating the 
testing problems cited by RSG in its attempts to implement the DOE test 
procedure for these basic models. Id. at 87 FR 43814. The alternate 
test procedure established in the Interim Waiver Order is based on the 
calibrated box method (i.e., Method 2 of AHRI 1250-2009) with 
modifications to the refrigerant enthalpy test provisions of this 
method. Id. at 87 FR 43813. Using the calibrated box method, the 
measured capacity includes the thermal loss through the evaporator of 
the single-packaged dedicated system under test. Id. The calibrated box 
method serves as the primary test method. A modified version of the 
single-packaged refrigerant enthalpy method is specified in the 
alternate test procedure for use as a secondary test method.\9\ Id. 
Under the modified refrigerant enthalpy method, the refrigerant liquid 
line length is reduced from 25 feet (as prescribed in AHRI 1250-2009) 
to a maximum of 5 feet, allows for the capacity measurements of 
multiple refrigerant circuits, and adds a calculation to estimate the 
single-packaged thermal loss of the unit under test. Id. The capacity 
as measured by the primary and secondary test methods must be within 6 
percent of one another for a valid test. Id. at 87 FR 43814.
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    \9\ A secondary test method's results are used to ensure the 
capacity tolerance is met when compared to the capacity determined 
by a primary test method, but are not used for rating performance.
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    The alternate test procedure established in the Interim Waiver 
Order differed from the alternate test procedure proposed by RSG with 
regard to the condenser air entering wet-bulb temperature test 
condition. Id. RSG proposed that the condenser air entering wet-bulb 
temperature test condition be 68 [deg]F for single-packaged dedicated 
systems that do not use evaporative dedicated condensing units, for 
which all or part of the equipment is located in the outdoor room. Id. 
Whereas, the alternate test procedure established in the Interim Waiver 
Order specifies the condensing air entering wet-bulb temperature as 65 
[deg]F, which maintains consistency with the requirements in Table 8 of 
AHRI 1250-2020. Id.
    In the Interim Waiver Order, DOE solicited comments from interested 
parties on all aspects of the petition and the specified alternate test 
procedure. 87 FR 43808, 43809. DOE did not receive any comments in 
response to the Interim Waiver Order.
    On May 4, 2023, DOE published a test procedure final rule (``May 
2023 Final Rule'') that established a new test procedure for walk-in 
coolers and walk-in freezers at appendix C1, in addition to specifying 
minor amendments to appendix C. 88 FR 28780, 28810. Appendix C1 
includes test provisions for multi-circuit single-package dedicated 
systems that are substantively the same as the methodology granted in 
the Interim Waiver Order. Use of appendix C1 is not required until the 
compliance date of any amended energy conservation standards based on 
the test procedure in appendix C1. Until such time, use of appendix C 
is required to demonstrate compliance with current standards. As 
discussed in the May 2023 Final Rule, the amendments to appendix C did 
not include provisions for multi-circuit single-package dedicated 
systems.\10\ As such, for the basic models subject to the Interim 
Waiver Order, the need for the waiver from appendix C will continue 
until such time as use of appendix C1 is required.
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    \10\ DOE notes a typographical error in Table III.8 of the May 
2023 Final Rule. 88 FR 28780, 28827. In that table, the interim 
waiver granted to RSG was indicated as being addressed by amendments 
to appendix C, with compliance beginning October 31, 2023. Id. The 
table should have indicated the RSG interim waiver as being 
addressed by appendix C1, with a compliance date corresponding to 
``Compliance date of updated standards.''
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    For the reasons explained here and in the Interim Waiver Order, 
absent a waiver the basic models identified by RSG in its petition 
cannot be tested and rated for energy consumption on a basis 
representative of their true energy consumption characteristics. 
Therefore, DOE has determined that the current test procedure for walk-
in cooler refrigeration systems would evaluate the subject basic models 
in a manner so unrepresentative of its true energy consumption 
characteristics as to provide materially inaccurate comparative data. 
DOE has reviewed the recommended procedure suggested by RSG and 
concludes that, with minor modification to the condenser air entering 
wet bulb temperature as discussed previously, it will allow for the 
accurate measurement of the energy use of the equipment, while 
alleviating the testing problems associated with RSG's implementation 
of DOE's applicable walk-in test procedure for the specified basic 
models.
    Thus, DOE is requiring that RSG test and rate specified walk-in 
basic models according to the alternate test procedure specified in 
this Decision and Order, which is identical to the alternate test 
procedure specified in the Interim Waiver Order.\11\
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    \11\ DOE notes that while the test provisions of this Decision 
and Order are identical to those presented in the Interim Waiver 
Order, the section numbering of the test provisions specified in 
this Decision and Order are slightly different than those sections 
specified in the Interim Waiver Order due to other section numbering 
changes made to appendix C by the May 2023 Final Rule.
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    This Decision and Order is applicable only to the basic models 
listed and does not extend to any other basic models. DOE evaluates and 
grants waivers for only those basic models specifically set out in the 
petition, not future models that may be manufactured by the petitioner. 
RSG may request that DOE extend the scope of this waiver to include 
additional basic models that employ the same technology as those listed 
in this waiver. 10 CFR 431.401(g). RSG may also submit another petition 
for waiver from the test procedure for additional basic models that 
employ a different technology and meet the criteria for test procedure 
waivers. 10 CFR 431.401(a)(1).
    DOE notes that it may modify or rescind the waiver at any time upon 
DOE's determination that the factual basis underlying the petition for 
waiver is incorrect, or upon a determination that the results from the 
alternate test procedure are unrepresentative of the basic models' true 
energy consumption characteristics. 10 CFR 431.401(k)(1). Likewise, RSG 
may request that DOE rescind or modify the waiver if the company 
discovers an error in the information provided to DOE as part of its 
petition, determines that the waiver is no longer needed, or for other

[[Page 81389]]

appropriate reasons. 10 CFR 431.401(k)(2).

III. Order

    After careful consideration of all the material that was submitted 
by RSG, in this matter, it is ordered that:
    (1) RSG must test and rate the following Norlake- and Masterbilt-
branded basic models with the test procedure set forth in paragraph 
(2).

------------------------------------------------------------------------
            Cooler basic models                 Freezer basic models
------------------------------------------------------------------------
CPB050PC-S-0..............................  CPF050PC-S-0
CPB075PC-S-0..............................  CPF075PC-S-0
CPB100PC-S-0..............................  CPF100PC-S-0
                                            CPF150PC-S-4
                                            CPF200PC-S-4
------------------------------------------------------------------------

    (2) The alternate test procedure for the RSG basic models 
identified in paragraph (1) of this Order is the test procedure for 
walk-in refrigeration systems prescribed by DOE at 10 CFR part 431, 
subpart R, appendix C (``appendix C'') as amended by the May 2023 Final 
Rule, except that multiple-circuit single-packaged dedicated systems 
shall use: (1) either the calibrated box method or an indoor air 
enthalpy test as the primary test method, as detailed below; (2) the 
modified refrigerant enthalpy method as the secondary test method, as 
detailed below; (3) the net capacity from the primary and secondary 
test methods must agree within  6 percent, as detailed 
below; and (4) reported values for the overall system shall be the 
summation of the gross capacities obtained from the modified 
refrigerant enthalpy method conducted for each refrigeration circuit 
included in the unit under test, as detailed below. All other 
requirements of appendix C as amended by the May 2023 Final Rule and 
DOE's regulations remain applicable.
    In appendix C:
    Revise section 3.1.1 to read as follows:
    3.1.1. In Table 1 of AHRI 1250-2009, Instrumentation Accuracy, 
refrigerant temperature measurements shall have a tolerance of 0.5 [deg]F for unit cooler in/out. Temperature measurements used 
to determine water vapor content of the air shall be accurate to within 
0.4 [deg]F. All other temperature measurements shall be 
accurate to 1.0 [deg]F.
    Revise section 3.1.4 to read as follows:
    3.1.4. In Tables 2 through 14 of AHRI 1250-2009, the Test Condition 
Outdoor Wet Bulb Temperature requirement and its associated tolerance 
apply only to units with evaporative cooling and single-packaged 
dedicated systems.
    Insert new section 3.1.8 as follows:
    3.1.8 Tables 3, 4, 7 and 8 of AHRI 1250-2009 shall be modified to 
read as follows:

                                   Table 3--Fixed Capacity Matched Refrigerator System, Condensing Unit Located Indoor
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                                                   Unit
                                      Unit      cooler air   Condenser
                                   cooler air    entering       air      Condenser  air  entering
        Test description            entering     relative     entering       wet-bulb,  [deg]F         Compressor  capacity          Test objective
                                   dry-bulb,    humidity,    dry-bulb,
                                     [deg]F        (%)        ([deg]F)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Off Cycle Fan Power.............           35          <50  ...........  ........................  Compressor Off.............  Measure fan input
                                                                                                                                 wattage during
                                                                                                                                 compressor off cycle.
Refrigeration Capacity..........           35          <50           90  75 \1\ or 65 \2\........  Compressor On..............  Determine Net
                                                                                                                                 Refrigeration Capacity
                                                                                                                                 of Unit Cooler, input
                                                                                                                                 power, and EER at
                                                                                                                                 Rating Condition.
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\1\ Required only for evaporative Dedicated Condensing Units
\2\ Maximum allowable value for Single-Packaged Dedicated Systems that do not use evaporative Dedicated Condensing Units, where all or part of the
  equipment is located in the outdoor room.


                                  Table 4--Fixed Capacity Matched Refrigerator System, Condensing Unit Located Outdoor
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                                                   Unit
                                      Unit      cooler air   Condenser
                                   cooler air    entering       air      Condenser  air  entering
        Test description            entering     relative     entering       wet-bulb,  [deg]F         Compressor  capacity          Test objective
                                   dry-bulb,    humidity,    dry-bulb,
                                     [deg]F        (%)        ([deg]F)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Off Cycle Fan Power.............           35          <50  ...........  ........................  Compressor Off.............  Measure fan input
                                                                                                                                 wattage during
                                                                                                                                 compressor off cycle.
Refrigeration Capacity A........           35          <50           95  75 \1\ or 68 \2\........  Compressor On..............  Determine Net
                                                                                                                                 Refrigeration Capacity
                                                                                                                                 of Unit Cooler, input
                                                                                                                                 power, and EER at
                                                                                                                                 Rating Condition.
Refrigeration Capacity B........           35          <50           59  54 \1\ or 46 \2\........  Compressor On..............  Determine Net
                                                                                                                                 Refrigeration Capacity
                                                                                                                                 of Unit Cooler, and
                                                                                                                                 system input power at
                                                                                                                                 moderate condition.
Refrigeration Capacity C........           35          <50           35  34 \1\ or 29 \2\........  Compressor On..............  Determine Net
                                                                                                                                 Refrigeration Capacity
                                                                                                                                 of Unit Cooler, and
                                                                                                                                 system input power at
                                                                                                                                 cold condition.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Required only for evaporative Dedicated Condensing Units.
\2\ Maximum allowable value for Single-Packaged Dedicated Systems that do not use evaporative Dedicated Condensing Units, where all or part of the
  equipment is located in the outdoor room.


                                     Table 7--Fixed Capacity Matched Freezer System, Condensing Unit Located Indoor
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                   Unit
                                      Unit      cooler air   Condenser
                                   cooler air    entering       air      Condenser  air  entering
        Test description            entering     relative     entering       wet-bulb,  [deg]F         Compressor  capacity          Test objective
                                   dry-bulb,    humidity,    dry-bulb,
                                     [deg]F        (%)        ([deg]F)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Off Cycle Fan Power.............          -10          <50  ...........  ........................  Compressor Off.............  Measure fan input
                                                                                                                                 wattage during
                                                                                                                                 compressor off cycle.
Refrigeration Capacity..........          -10          <50           90  75 \1\ or 65 \2\........  Compressor On..............  Determine Net
                                                                                                                                 Refrigeration Capacity
                                                                                                                                 of Unit Cooler, input
                                                                                                                                 power, and EER at
                                                                                                                                 Rating Condition.
Defrost Frost Load..............          -10      Various           90  75 \1\ or 65 \2\........  System Dependent...........  Test according to
                                                                                                                                 section C11 of AHRI
                                                                                                                                 1250-2009.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Required only for evaporative Dedicated Condensing Units.

[[Page 81390]]

 
\2\ Maximum allowable value for Single-Packaged Dedicated Systems that do not use evaporative Dedicated Condensing Units, where all or part of the
  equipment is located in the outdoor room.


                                     Table 8--Fixed Capacity Matched Freezer System, Condensing Unit Located Outdoor
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                   Unit
                                      Unit      cooler air   Condenser
                                   cooler air    entering       air      Condenser  air  entering
        Test description            entering     relative     entering       wet-bulb,  [deg]F         Compressor  capacity          Test objective
                                   dry-bulb,    humidity,    dry-bulb,
                                     [deg]F        (%)        ([deg]F)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Off Cycle Fan Power.............          -10          <50  ...........  ........................  Compressor Off.............  Measure fan input
                                                                                                                                 wattage during
                                                                                                                                 compressor off cycle.
Refrigeration Capacity A........          -10          <50           95  75 \1\ or 68 \2\........  Compressor On..............  Determine Net
                                                                                                                                 Refrigeration Capacity
                                                                                                                                 of Unit Cooler, input
                                                                                                                                 power, and EER at
                                                                                                                                 Rating Condition.
Refrigeration Capacity B........          -10          <50           59  54 \1\ or 46 \2\........  Compressor On..............  Determine Net
                                                                                                                                 Refrigeration Capacity
                                                                                                                                 of Unit Cooler, input
                                                                                                                                 power, and EER at
                                                                                                                                 Rating Condition.
Refrigeration Capacity C........          -10          <50           35  34 \1\ or 29 \2\........  Compressor On..............  Determine Net
                                                                                                                                 Refrigeration Capacity
                                                                                                                                 of Unit Cooler, input
                                                                                                                                 power, and EER at
                                                                                                                                 Rating Condition.
Defrost Frost Load..............          -10      Various           95  75 \1\ or 68 \2\........  System Dependent...........  Test according to
                                                                                                                                 section C11 of AHRI
                                                                                                                                 1250-2009.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Required only for evaporative Dedicated Condensing Units.
\2\ Maximum allowable value for Single-Packaged Dedicated Systems that do not use evaporative Dedicated Condensing Units, where all or part of the
  equipment is located in the outdoor room.

    Remove section 3.2.5.
    Add a new section 4, following section 3.5 Hot Gas Defrost 
Refrigeration Systems

4.0 Multiple-Circuit Single-Packaged Dedicated Systems

    When conducting testing in accordance with AHRI 1250-2009 
(incorporated by reference; see 10 CFR 431.303), the following 
modifications must be made.

4.1 Specific Modifications: Test Conditions and Tolerance

    4.1.1 Replace section C3.1.2 of AHRI 1250-2009 with the following: 
Air wet-bulb and dry-bulb temperatures entering the Single-Packaged 
Dedicated System at its evaporator return and condenser air inlet shall 
be measured based on the airflow area at the point of measurement. One 
measuring station is required for each 2.0 ft\2\ of the first 10.0 
ft\2\ of airflow area and one additional measuring station is required 
for each 4.0 ft\2\ of airflow area above 10.0 ft\2\. A minimum of two 
stations shall be used and the number of measuring stations shall be 
rounded up to the next whole number.
    4.1.2 Replace section C3.1.5 of AHRI 1250-2009 with the following: 
If sampling tubes are used, each tube opening may be considered a 
temperature measuring station provided the openings are uniformly 
spaced along the tube, the airflow rates entering each port are 
relatively uniform (15%) and the arrangement of tubes 
complies with the location requirements of section C3.1.2 of AHRI 1250-
2009. Additionally, a one-time temperature traverse shall be made over 
the measurement surface, prior to the tests to assess the temperature 
variation and ensure it complies with the allowable deviation specified 
in section C3.1.4 of AHRI 1250-2009. (Refer to ANSI/ASHRAE Standard 
41.1 for more information and diagrams). If sampling tubes are not used 
for single-packaged dedicated systems that do not use evaporative 
dedicated condensing units, a single air wet-bulb or RH sensor may be 
used. When used, this sensor shall be located at the geometric center 
of the largest condenser coil face and 6-12 inches from the condenser 
coil.
    4.1.3 Replace section 3.1.6 of AHRI 1250-2009 with the following: 
Refrigerant temperatures entering and leaving the evaporator section of 
the Single-Packaged Dedicated System shall be measured by a temperature 
measuring instrument placed in a thermometer well and inserted into the 
refrigerant stream. These wells shall be filled with non-solidifying, 
thermal conducting liquid or paste to ensure the temperature sensing 
instrument is exposed to a representative temperature. The entering 
temperature of the refrigerant shall be measured within six pipe 
diameters upstream of the expansion device. If the refrigerant tube 
outer diameter is less than \1/2\-inch, the refrigerant temperature may 
be measured using the average of two temperature measuring instruments 
with a minimum accuracy of 0.5 [deg]F placed on opposite 
sides of the refrigerant tube surface. In this case, the refrigerant 
tube shall be insulated with 1-inch-thick insulation from a point 6 
inches upstream of the measurement location to a point 6 inches 
downstream of the measurement location. Also, the entering measurement 
location may be moved to a location 6 inches upstream of the expansion 
device.

4.2 Refrigerant Properties Measurement

    4.2.1 Replace section C3.3.1 of AHRI 1250-2009 with the following: 
With the equipment operating at the desired test conditions, the 
temperature and pressure of the refrigerant leaving the unit cooler, 
entering the expansion device, and entering and leaving the compressor 
shall be measured. For cases where the calibrated box method or indoor 
air enthalpy method is also conducted, data used to calculate capacity 
according to the single-package refrigerant enthalpy method and the 
additional method shall be collected over the same intervals.
    4.2.2 Replace section C3.3.3 of AHRI 1250-2009 with the following: 
For Single-Packaged Dedicated Systems tested using either the 
calibrated box method or the indoor air enthalpy method as the primary 
measurement and the single-package refrigerant enthalpy method as the 
secondary method, a preliminary test for Rating Condition A using the 
primary method is required prior to setting up the refrigerant enthalpy 
method measurements. In preparation for this preliminary test, 
temperature sensors shall be attached to the equipment's evaporator and 
condenser coils. The sensors shall be located at points that are not 
affected by vapor superheat or liquid subcooling. Placement near the 
midpoint of the coil, at a return bend, is recommended. The preliminary 
test shall be conducted with the requirement that the temperatures of 
the on-coil sensors be included with the regularly recorded data. After 
the preliminary test is completed, the refrigerant shall be removed 
from the equipment, and the refrigerant enthalpy measurement setup 
shall be completed. The equipment

[[Page 81391]]

shall be evacuated and recharged with refrigerant. The test shall then 
be repeated. Once steady-state operation is achieved, refrigerant shall 
be added or removed until, as compared to the average values from the 
preliminary test, the following conditions are achieved: (1) each on-
coil temperature sensor indicates a reading that is within 1.0 [deg]F, (2) the temperatures of the refrigerant entering and 
leaving the compressor are within 4 [deg]F, and (3) the 
refrigerant temperature entering the expansion device is within 1 [deg]F. Once these conditions have been achieved over an 
interval of at least ten minutes, refrigerant charging equipment shall 
be removed, and the remaining tests shall be conducted.
    4.2.3 When conducting the refrigerant enthalpy method for a Single-
Packaged Dedicated System, the length of the added liquid line 
conducting refrigerant out of the system, to the flow meter, and back 
into the system shall be no more than 5 feet. No such modification to 
the suction line shall be made.

4.3 Methods for Testing for Walk-In Cooler and Freezer Systems That 
Have Matched Unit Coolers and Condensing Units

    Disregard section C5 of AHRI 1250-2009 and instead test according 
to the following method:
    4.3.1 The Refrigeration Capacity for Single-Packaged Dedicated 
Systems shall be determined using either the Calibrated Box method or 
the Indoor Air Enthalpy method as a primary test method and the Single-
Package Refrigerant Enthalpy method as the secondary test method.
    4.3.1.1 Single-Package Refrigerant Enthalpy method shall determine 
gross refrigeration capacity by measuring the enthalpy change and the 
mass flow rate of the refrigerant using a single set of measurements.
    4.3.1.2 Calibrated Box method shall determine net refrigeration 
capacity by measuring the heat input to the calibrated box, including 
thermal transfer through the calibrated box walls.
    4.3.2 Indoor Air Enthalpy method shall determine net refrigeration 
capacity of Single-Packaged Dedicated System and input power in 
accordance with ASHRAE 37-2009, Figure C4 of AHRI 1250-2020, and the 
following modifications.
    4.3.2.1 Net refrigeration capacity is determined by measuring 
airflow rate and the dry-bub temperature and water vapor content of the 
air that enters and leaves the coil.
    4.3.2.2 Air enthalpies shall be determined in accordance with ANSI/
ASHRAE 41.6. Entering air is to be sufficiently dry as to not produce 
frost on the evaporator coil. Therefore, only sensible capacity 
measured by dry bulb change shall be used to calculate capacity.
    4.3.3 Testing Sequence. The primary test method shall be used to 
measure the capacity for Rating Condition A prior to set-up of the 
Single-Package Refrigerant Enthalpy Measurement. After set-up of the 
Refrigerant Enthalpy method, the Net Capacity shall be measured using 
both the primary test method and the Refrigerant Enthalpy method. The 
Net Capacity measurement using the Refrigerant Enthalpy method shall be 
within 6 percent of the net capacity measurement using the primary 
method.
    If a capacity balance within tolerance is not initially achieved, 
take steps to reduce the thermal losses of the Single-Packaged 
Dedicated System evaporator compartment by sealing air gaps and 
potentially adding more external insulation. If using the Calibrated 
Box method as the primary method, achieving a capacity balance may 
require conducting the calibration with calibrated box insulation 
material at the same average temperature as during capacity 
measurement, or using multiple calibrations conducted at different 
average insulation material temperatures and using these data to 
construct a correlation for the calibration coefficient, 
Kcb, as a function of average insulation temperature. The 
official performance measurements are based on the primary method 
testing without any air gap sealing and additional external insulation 
used to achieve the 6 percent energy balance in place.
    4.3.4 The refrigerant enthalpy method Net Capacity shall be 
calculated from the Gross Capacity Measurement as follows.

qss,2 = Qref - 3.412 x EFcomp,on-Qsploss

Where Qsploss represents the Single-Packaged Dedicated System thermal 
losses through the walls of the evaporator side of the Single-Packaged 
Dedicated System to the condenser side and to the exterior ambient, and 
shall be calculated as follows.

Qsploss = UAcond x (Tcondside-Tevapside) + UAamb x (Tamb-Tevapside)


Where:

UAcond and UAamb are, for the condenser/evaporator partition and the 
evaporator compartment walls exposed to ambient air, respectively, 
the product of the overall heat transfer coefficient and surface 
area of the unit as manufactured, i.e., without external insulation 
that might have been added during the test;
Tevapside is the air temperature in the evaporator compartment;
Tcondside is the air temperature in the condenser compartment; and
Tamb is the air temperature outside the Single-Packaged Dedicated 
System.

    The Net Capacity to be used in AWEF calculations shall be the net 
capacity measured using the primary method.
    4.3.5 Upon the completion of the Rating Condition A steady state 
test, an off-cycle evaporator fan power test shall be conducted to 
measure the evaporator fan power consumption during a compressor-off 
period in accordance with section C10 of AHRI 1250-2009.
    4.3.6 Upon the completion of the Rating Condition A steady state 
test for walk-in freezer systems, a mandatory defrost test shall be 
conducted to establish the energy input for a defrost cycle.
    4.3.7 Upon the completion of the Rating Condition A steady state 
test, off-cycle evaporator fan power test, and defrost test (for walk-
in freezer systems), the Rating Condition B and C steady state tests 
shall be conducted. Capacity balance as described in section C9.2 of 
AHRI 1250-2020 for Rating Condition A is not required for Rating 
Conditions B and C.

4.4 Test Chamber Requirements

    Disregard section C6 of AHRI 1250-2009 and instead test according 
to the following method:
    4.4.1 For single-packaged dedicated systems, test chamber 
requirements shall be as follows:
    a. For the calibrated box method, follow ASHRAE 16-2016 Section 6.1 
for calibrated type calorimeters excluding water and water energy 
inputs for the indoor-side compartment.
    b. For the indoor air enthalpy method, follow ASHRAE 37-2009.

4.5 Single-Packaged Dedicated System Refrigerant Enthalpy Method

    4.5.1 General Description. In this method, capacity is determined 
from the refrigerant enthalpy change and flow rate. Enthalpy changes 
are determined from measurements of entering and leaving pressures and 
temperatures of the refrigerant, and the flow rate is determined by a 
suitable flow meter in the liquid line. This method shall not be used 
for tests in which the refrigerant liquid leaving the flow meter is 
subcooled less than 3 [deg]F or for tests in which any instantaneous 
measurement of the superheat of the vapor leaving the evaporator coil 
is less than 5 [deg]F. Supplementary cooling may be artificially 
provided for the liquid line to ensure enough subcooling when

[[Page 81392]]

making measurements to establish the capacity balance for Rating 
Condition A, however, no official measurements used to calculate AWEF 
may be made while providing such supplementary cooling.
    4.5.2 Measurements. Refer to Section 4.1 of this appendix and 
section C3 of AHRI 1250-2009 for requirements of air-side and 
refrigerant-side measurements.
    4.5.3 Test Setup and Procedure. Refer to Section 4.4 of this 
appendix, section C7 of AHRI 1250-2009, and Figure C3 of this section 
for specific test setup. The length of the added liquid line shall be 5 
feet, maximum.
BILLING CODE 6450-01-P
[GRAPHIC] [TIFF OMITTED] TN22NO23.258

    4.5.4 Data to be Measured and Recorded. Refer to ``Refrigerant 
Enthalpy Method'' in Table C2 in section C7.2 of AHRI 1250-2009 for the 
required data that need to measured and recorded, except as follows.
    4.5.4.1 Water vapor content of air entering the unit cooler 
(evaporator) and condensing unit may be measured using a wet bulb 
temperature measurement or a relative humidity sensor, but both are not 
required.
    4.5.4.2 Wet bulb temperature of air leaving the unit cooler 
(evaporator) and condensing unit need not be measured.
    4.5.4.3 Required refrigerant pressure measurement includes only 
subcooled liquid entering the expansion valve and superheated vapor 
exiting the unit cooler (evaporator).
    4.5.4.4 Only one refrigerant mass flow measurement is required.
    4.5.4.5 Measurement of Refrigerant oil flow rate and oil/
refrigerant mass ratio are not required.
    4.5.5 Refrigeration Capacity Calculation.

[[Page 81393]]

    4.5.5.1 The refrigerant-side gross capacity is calculated by

Qref = mref(hout-hin)

    4.5.5.2 Measurement of Capacity for a Single-Packaged Dedicated 
System with Multiple Refrigeration Circuits.
    For a Single-Packaged Dedicated System with multiple refrigeration 
circuits, apply the refrigerant enthalpy method separately for each 
circuit and sum the separately-measured gross refrigeration capacities.

4.6 Calibrated Box Test Procedure

    4.6.1 Measurements. Refer to section 4.1 of this section and 
section C3 of AHRI 1250-2009 for requirements of air-side and 
refrigerant-side measurements.
    4.6.2 Apparatus setup for Calibrated Box Calibration and Test. 
Refer to section 4.4 of this section, section C7 of AHRI 1250-2009, and 
Figure C4 of this section for specific test setup.
BILLING CODE 6510-01-C
[GRAPHIC] [TIFF OMITTED] TN22NO23.259

    4.6.2.1 The calibrated box shall be installed in a temperature-
controlled enclosure in which the temperature can be maintained at a 
constant level. When using the calibrated box method for Single-
Packaged Dedicated Systems, the enclosure air temperature shall be 
maintained such that the condenser air entering conditions are as 
specified for the test.
    4.6.2.2 The temperature-controlled enclosure shall be of a size 
that will provide clearances of not less than 18 in at all sides, top 
and bottom, except that clearance of any one surface may be reduced to 
not less than 5.5 inches.
    4.6.2.3 The heat leakage of the calibrated box shall be noted in 
the test report.
    4.6.2.4 Refrigerant lines within the calibrated box shall be well 
insulated to avoid appreciable heat loss or gain.
    4.6.2.5 Instruments for measuring the temperature around the 
outside of the calibrated box to represent the enclosure temperature 
Ten shall be located at the center of each wall, ceiling, 
and floor.
    Exception: in the case where a clearance around the outside of the 
calibrated box, as indicated above, is reduced to less than 18 inches, 
the number of temperature-measuring devices on the outside of that 
surface shall be increased to six, which shall be treated as a single 
temperature to be averaged with the temperature of each of the other 
five surfaces. There will be six rectangular sections of equal area, 
and each of these six sections will have a temperature-measuring 
instrument located at its center. If the refrigeration system is 
mounted at the location that would cover the center of the face on 
which it is mounted, up to four temperature measurements shall be used 
on that face to represent its temperature. Each sensor shall be aligned 
with the center of the face's nearest outer edge and centered on the 
distance between that edge and the single-packaged unit (this is 
illustrated in Figure C5 when using surface temperature sensors), and 
they shall be treated as a single temperature to be averaged with the 
temperature of each of the other five surfaces. However, any of these 
sensors shall be omitted if either (a) the distance between the outer

[[Page 81394]]

edge and the single-packaged unit is less than one foot or (b) if the 
sensor location would be within two feet of any of the foot-square 
surfaces discussed below representing a warm discharge air impingement 
area. In this case, the remaining sensors shall be used to represent 
the average temperature for the surface.
    One of the following two approaches shall be used for the box 
external temperature measurement. Box calibration and system capacity 
measurement shall both be done using the same one of these approaches.
    4.6.2.5.1 Air temperature sensors. Each temperature sensor shall be 
at a distance of 6 inches from the calibrated box. If the clearance 
from a surface of the box (allowed for one surface only) is less than 
12 inches, the temperature measuring instruments shall be located 
midway between the outer wall of the calibrated box and the adjacent 
surface.
    4.6.2.5.2 Surface temperature sensors. Surface temperature sensors 
shall be mounted on the calibrated box surfaces to represent the 
enclosure temperature, Ten.
    Additional surface temperature sensors may be used to measure 
external hot spots during refrigeration system testing. If this is 
done, two temperature sensors shall be used to measure the average 
temperature of the calibrated box surface covered by the condensing 
section--they shall be centered on equal-area rectangles comprising the 
covered calibrated box surface whose common sides span the short 
dimension of this surface. Additional surface temperature sensors may 
be used to measure box surfaces on which warm condenser discharge air 
impinges. A pattern of square surfaces measuring one foot square shall 
be mapped out to represent the hot spot upon which the warm condenser 
air impinges. One temperature sensor shall be used to measure surface 
temperature at the center of each square (see Figure C5 of this 
section). A drawing showing this pattern and identifying the surface 
temperature sensors shall be provided in the test report. The average 
surface temperature of the overall calibrated box outer surface during 
testing shall be calculated as follows.
[GRAPHIC] [TIFF OMITTED] TN22NO23.260

Where:
Ai is the surface area of the i\th\ of the six calibrated box 
surfaces;
Ti is the average temperature measured for the i\th\ surface;
Aj is half of the surface area of the calibrated box covered by the 
condensing section;
T'j is the j\th\ of the two temperature measurements underneath the 
condensing section;
T1 is the average temperature of the four or fewer measurements 
representing the temperature of the face on which the single-
packaged system is mounted, prior to adjustments associated with hot 
spots based on measurements Tj and/or Tk;
Ak is the area of the k\th\ of n 1-square-foot surfaces used to 
measure the condenser discharge impingement area hot spot; and,
T''k is the k\th\ of the n temperature measurements of the condenser 
discharge impingement area hot spot.
BILLING CODE 6450-01-P

[[Page 81395]]

[GRAPHIC] [TIFF OMITTED] TN22NO23.261

BILLING CODE 6450-01-C
    4.6.2.6 Heating means inside the calibrated box shall be shielded 
or installed in a manner to avoid radiation to the Single-Packaged 
Dedicated System, the temperature measuring instruments, and to the 
walls of the box. The heating means shall be constructed to avoid 
stratification of temperature, and suitable means shall be provided for 
distributing the temperature uniformly.
    4.6.2.7 The average air dry-bulb temperature in the calibrated box 
during Single-Packaged Dedicated System tests and calibrated box heat 
leakage tests shall be the average of eight temperatures measured at 
the corners of the box at a distance of 2 inches to 4 inches from the 
walls. The instruments shall be shielded from any cold or warm surfaces 
except that they shall not be shielded from the adjacent walls of the 
box. The Single-Packaged Dedicated System under test shall be mounted 
such that the temperature instruments are not in the direct air stream 
from the discharge of the Single-Packaged Dedicated System.
    4.6.3 Calibration of the Calibrated Box. Calibration of the 
Calibrated Box shall occur prior to installation of the Single-Packaged 
Dedicated System. This shall be done either (a) prior to cutting the 
opening needed to install the Single-Packaged Dedicated System, or (b) 
with an insulating panel with the same thickness and thermal resistance 
as the box wall installed in the opening intended for the Single-
Packaged Dedicated System installation. Care shall be taken to avoid 
thermal shorts in the location of the opening either during calibration 
or during subsequent installation of the Single-Packaged Dedicated 
System. A calibration test shall be made for air movements comparable 
to those expected for Single-Packaged Dedicated System capacity 
measurement, i.e., with air volume flow rate within 10 percent of the 
air volume flow rate of the Single-Packaged Dedicated System 
evaporator.
    4.6.3.1 The heat input shall be adjusted to maintain an average box 
temperature not less than 25.0 [deg]F above the test enclosure 
temperature.
    4.6.3.2 The average dry-bulb temperature inside the calibrated box 
shall not vary more than 1.0 [deg]F over the course of the calibration 
test.
    4.6.3.3 A calibration test shall be the average of eleven 
consecutive hourly readings when the box has reached a steady-state 
temperature condition.
    4.6.3.4 The box temperature shall be the average of all readings 
after a steady-state temperature condition has been reached.
    4.6.3.5 The calibrated box has reached a steady-state temperature 
condition when:

[[Page 81396]]

    4.6.3.5.1 The average box temperature is not less than 25 [deg]F 
above the test enclosure temperature.
    4.6.3.5.2 Temperature variations do not exceed 5.0 [deg]F between 
temperature-measuring stations.
    4.6.3.5.3 Temperatures do not vary by more than 2 [deg]F at any one 
temperature-measuring station.
    4.6.4 Data to be Measured and Recorded. Refer to Table C2 in 
section C7.2 of AHRI 1250-2020 for the required data that need to 
measured and recorded.
    4.6.5 Refrigeration Capacity Calculation.
    4.6.5.1 The heat leakage coefficient of the calibrated box is 
calculated by
[GRAPHIC] [TIFF OMITTED] TN22NO23.262

    4.6.5.2 For each Dry Rating Condition, calculate the Net Capacity:

qss = Kcb (Ten-Tcb) + 3.412 x Ec

    (3) Representations. RSG may not make representations about the 
efficiency of a basic model listed in paragraph (1) of this Order for 
compliance, marketing, or other purposes unless that basic model has 
been tested in accordance with the provisions set forth in this 
alternate test procedure and such representations fairly disclose the 
results of such testing.
    (4) This Order shall remain in effect until the date upon which use 
of appendix C1 is required to demonstrate compliance with any amended 
energy conservation standards based on the test procedure in appendix 
C1.
    (5) This Order is issued on the condition that the statements and 
representations provided by RSG are valid. If RSG makes any 
modifications to the controls or configurations of any basic model 
subject to this Order, such modifications will render the waiver 
invalid with respect to that basic model, and RSG will either be 
required to use the current Federal test method or submit a new 
application for a test procedure waiver. DOE may rescind or modify this 
waiver at any time if it determines the factual basis underlying the 
petition for the waiver is incorrect, upon a determination that the 
results from the alternate test procedure are unrepresentative of a 
basic model's true energy consumption characteristics, or for other 
appropriate reasons. 10 CFR 431.401(k)(1). Likewise, RSG may request 
that DOE rescind or modify the waiver if RSG discovers an error in the 
information provided to DOE as part of its petition, determines that 
the waiver is no longer needed, or for other appropriate reasons. 10 
CFR 431.401(k)(2).
    (6) Issuance of this Order does not release RSG from the applicable 
requirements set forth at 10 CFR part 429.
    DOE makes decisions on waivers and interim waivers for only those 
basic models specifically set out in the petition, not future models 
that may be manufactured by the petitioner. RSG may submit a new or 
amended petition for waiver and request for grant of interim waiver, as 
appropriate, for additional basic models of single-packaged dedicated 
systems with multiple refrigeration circuits. Alternatively, if 
appropriate, RSG may request that DOE extend the scope of a waiver or 
an interim waiver to include additional basic models employing the same 
technology as the basic models set forth in the original petition 
consistent with 10 CFR 431.401(g).

Signing Authority

    This document of the Department of Energy was signed on November 
17, 2023, by Jeffrey Marootian, Principal Deputy Assistant Secretary 
for Energy Efficiency and Renewable, pursuant to delegated authority 
from the Secretary of Energy. That document with the original signature 
and date is maintained by DOE. For administrative purposes only, and in 
compliance with requirements of the Office of the Federal Register, the 
undersigned DOE Federal Register Liaison Officer has been authorized to 
sign and submit the document in electronic format for publication, as 
an official document of the Department of Energy. This administrative 
process in no way alters the legal effect of this document upon 
publication in the Federal Register.

    Signed in Washington, DC, on November 17, 2023.
Treena V. Garrett,
Federal Register Liaison Officer, U.S. Department of Energy.
[FR Doc. 2023-25873 Filed 11-21-23; 8:45 am]
BILLING CODE 6450-01-P