[Federal Register Volume 89, Number 51 (Thursday, March 14, 2024)]
[Proposed Rules]
[Pages 18555-18578]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-05462]


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 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
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 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
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  Federal Register / Vol. 89, No. 51 / Thursday, March 14, 2024 / 
Proposed Rules  

[[Page 18555]]



DEPARTMENT OF ENERGY

10 CFR Part 431

[EERE-2017-BT-STD-0009]
RIN 1904-AD79


Energy Conservation Program: Energy Conservation Standards for 
Walk-In Coolers and Freezers

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

ACTION: Notification of data availability and request for comment.

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

SUMMARY: On September 5, 2023, the U.S. Department of Energy (``DOE'') 
published a notice of proposed rulemaking (``NOPR''), in which DOE 
proposed amended energy conservation standards for walk-in coolers and 
walk-in freezers (``September 2023 NOPR''). In this notification of 
data availability (``NODA''), DOE is updating portions of its analysis 
for walk-in coolers and walk-in freezers based on information DOE 
received in response to DOE's September 2023 NOPR. DOE requests 
comments, data, and information regarding the updated analysis.

DATES: DOE will accept comments, data, and information regarding this 
NODA no later than April 15, 2024.

ADDRESSES: Interested persons are encouraged to submit comments using 
the Federal eRulemaking Portal at www.regulations.gov under docket 
number EERE-2017-BT-STD-0009. Follow the instructions for submitting 
comments. Alternatively, interested persons may submit comments, 
identified by docket number EERE-2017-BT-STD-0009, by any of the 
following methods:
    (1) Email: [email protected]. Include the docket number 
EERE-2017-BT-STD-0009 in the subject line of the message.
    (2) Postal Mail: Appliance and Equipment Standards Program, U.S. 
Department of Energy, Building Technologies Office, Mailstop EE-5B, 
1000 Independence Avenue SW, Washington, DC 20585-0121. If possible, 
please submit all items on a compact disc (CD), in which case it is not 
necessary to include printed copies.
    No telefacsimiles (``faxes'') will be accepted. For detailed 
instructions on submitting comments and additional information on this 
process, see section III of this document.
    Docket: The docket for this activity, which includes Federal 
Register notices, comments, and other supporting documents/materials, 
is available for review at www.regulations.gov. All documents in the 
docket are listed in the www.regulations.gov index. However, not all 
documents listed in the index may be publicly available, such as 
information that is exempt from public disclosure.
    The docket web page can be found at www.regulations.gov/docket/EERE-2017-BT-STD-0009. The docket web page contains instructions on how 
to access all documents, including public comments, in the docket. See 
section III of this document for information on how to submit comments 
through www.regulations.gov.

FOR FURTHER INFORMATION CONTACT: 
    Mr. Troy Watson, 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. 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].
    For further information on how to submit a comment, review other 
public comments and the docket, or participate in the public meeting, 
contact the Appliance and Equipment Standards Program staff at (202) 
287-1445 or by email: [email protected].

SUPPLEMENTARY INFORMATION: 

Table of Contents

I. Background
II. Discussion
    A. Engineering Analysis
    1. Non-Display Doors
    a. Maximum Daily Energy Consumption Allowances for Non-Display 
Doors With Certain Electrical Components
    b. Adjustment of U-Factors and Resulting Thermal Load
    2. Dedicated Condensing Units and Single-Packaged Dedicated 
Systems
    a. More Efficient Single Speed Compressors
    b. Off-Cycle Ancillary Power
    c. Low GWP Refrigerant Transition
    d. Miscellaneous Updates to the Engineering Analysis Spreadsheet
    3. Unit Coolers
    a. Cost Assumptions at Max-Tech Efficiency Levels
    b. Unit Cooler Fan Power
    c. Miscellaneous Updates to the Unit Cooler Analysis
    B. Trial Standard Levels
    1. Refrigeration Systems
    2. Non-Display Doors
    C. Analytical Results
    1. Life-Cycle Cost and Payback Period Analysis
    a. Application of the Low-GWP Refrigerant Transition to Specific 
Regions
    b. Results for Refrigeration Systems
    c. Results for Non-Display Doors
    2. National Impacts Analysis
    a. Non-Display Doors
    b. Significance of Energy Savings
    c. Net Present Value of Consumer Costs and Benefits
    D. Updated Equations for Proposed Standards
    1. Energy Consumption Equations for Non-Display Doors
    2. AWEF2 Equations
III. Public Participation
IV. Approval of the Office of the Secretary

I. Background

    The Energy Policy and Conservation Act, Public Law 94-163, as 
amended (``EPCA''),\1\ authorizes DOE to regulate the energy efficiency 
of a number of consumer products and certain industrial equipment. (42 
U.S.C. 6291-6317) Title III, Part C of EPCA,\2\ established the Energy 
Conservation Program for Certain Industrial Equipment. (42 U.S.C. 6311-
6317) Such equipment includes walk-in coolers and walk-in freezers \3\ 
(hereafter referred to

[[Page 18556]]

as ``walk-ins'' or ``WICFs''), the subject of this rulemaking.
---------------------------------------------------------------------------

    \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 re-designated Part A-1.
    \3\ Walk-in coolers and walk-in freezers are defined as an 
enclosed storage space, including but not limited to panels, doors, 
and refrigeration systems, refrigerated to temperatures, 
respectively, above, and at or below 32 degrees Fahrenheit that can 
be walked into, and has a total chilled storage area of less than 
3,000 square feet; however, the terms do not include products 
designed and marketed exclusively for medical, scientific, or 
research purposes. 10 CFR 431.302.
---------------------------------------------------------------------------

    DOE defines ``walk-ins'' as an enclosed storage space, including 
but not limited to panels, doors, and refrigeration systems, 
refrigerated to temperatures, respectively, above, and at or below 32 
degrees Fahrenheit that can be walked into, and has a total chilled 
storage area of less than 3,000 square feet; however, the terms do not 
include products designed and marketed exclusively for medical, 
scientific, or research purposes. 10 CFR 431.302. Rather than 
establishing standards for complete walk-in systems, DOE has 
established standards for the principal components that make up a walk-
in (i.e., doors, panels, and refrigeration systems).
    On September 5, 2023, DOE published a notice of proposed rulemaking 
(``NOPR'') in the Federal Register regarding energy conservation 
standards for walk-in coolers and freezers (``September 2023 NOPR''). 
88 FR 60746. Specifically, DOE proposed amended standards for walk-in 
non-display doors and walk-in refrigeration systems. DOE did not 
propose to amend the standard for walk-in panels or display doors. For 
walk-in refrigeration systems, DOE proposed amended standards in terms 
of the newly adopted annual walk-in energy factor 2 (``AWEF2'') 
metric.\4\ The technical support document (``TSD'') that presented the 
methodology and results of the September 2023 NOPR analysis 
(``September 2023 NOPR TSD'') is available at www.regulations.gov/document/EERE-2017-BT-STD-0009-0046. Additionally, on September 28, 
2023, DOE published a notification of data availability (``September 
2023 NODA'') summarizing additional comments received on the June 2022 
Preliminary Analysis (87 FR 39008) that were considered but not 
discussed in the September 2023 NOPR. 88 FR 66710.
---------------------------------------------------------------------------

    \4\ DOE adopted the AWEF2 metric in a test procedure final rule 
published on May 4, 2023. 88 FR 28780.
---------------------------------------------------------------------------

    On September 27, 2023, DOE held a public webinar (``September 2023 
Public Webinar'') in which it presented an overview of the topics 
addressed in the September 2023 NOPR, allowed time for prepared general 
statements by participants, and encouraged all interested parties to 
share their views on issues affecting this rulemaking.
    In response to the September 2023 NOPR, DOE received additional 
data and information regarding walk-in non-display doors and 
refrigeration systems, which is summarized in sections II.A and II.D.2 
of this document.
    Upon consideration of the views shared in the September 2023 Public 
Webinar and public comments DOE received in response to the September 
2023 NOPR, this NODA presents updated analysis for walk-in non-display 
doors and refrigeration systems. DOE is requesting comments, data, and 
information regarding the updated analysis.
    DOE notes that it is continuing to consider all of the stakeholder 
comments received in response to the September 2023 NOPR and September 
2023 Public Webinar in further development of the rulemaking. As 
discussed in the September 2023 NOPR, based on consideration of all of 
the public comments received, DOE may adopt energy efficiency levels 
that are either higher or lower than the proposed standards, or some 
combination of level(s) that incorporate the proposed standards in 
part.

II. Discussion

    In the following sections, DOE details its updated analysis for 
walk-in non-display doors and refrigeration systems.

A. Engineering Analysis

1. Non-Display Doors
a. Maximum Daily Energy Consumption Allowances for Non-Display Doors 
With Certain Electrical Components
    In the September 2023 NOPR, DOE assumed for its analysis that 
baseline non-display doors had 3.5-inch-thick insulation for coolers 
and 4-inch-thick insulation for freezers, wood framing materials, a 
viewing window, and anti-sweat heat around the perimeter of the door 
leaf without controls. 88 FR 60746, 60769. DOE did not consider 
lighting or other electrical components in its baseline representative 
units for non-display doors. Id. As such, DOE only considered design 
options relevant to the design of the baseline representative units, 
including: anti-sweat controls, reduced anti-sweat heat, improvements 
to the framing systems to make the frame more thermally insulative, and 
increased insulation thickness. Id. at 88 FR 60770.
    Kolpak commented that while it agrees with providing limits on door 
components, it disagrees with the overall formulas representing the 
proposed energy conservation standards for manual non-display doors. 
(Kolpak, No. 66, Attachment 1 at pp. 1, 3) \5\ Kolpak stated that its 
basic models are fully compliant with DOE's current regulations, but 
that it believes the new proposed maximum daily energy consumption 
(``MDEC'') formulas are impossibly stringent. (Kolpak, No. 66, 
Attachment 1 at p. 1) Kolpak stated that when considering all 
electricity-consuming devices that are installed on its doors, 
including the anti-sweat heater wire, door light, heated ventilator, 
heated viewing window, and thermometer/temperature alarms, the proposed 
standards would not be able to be met. (Id.) Kolpak provided 
calculations of the daily energy consumption of six different doors for 
both cooler and freezer applications to support their comment. (Kolpak, 
No. 66, Attachment 2)
---------------------------------------------------------------------------

    \5\ The parenthetical reference provides a reference for 
information located in the relevant docket for this rulemaking, 
which is maintained at www.regulations.gov. The references are 
arranged as follows: (commenter name, comment docket ID number, 
attachment number (if there are multiple attachments in a single 
comment submission), page of that document).
---------------------------------------------------------------------------

    The test procedure for non-display doors requires the direct and 
indirect electrical energy consumption of electrical components be 
calculated and included in the determination of daily energy 
consumption (``DEC'') using rated power of electrical components sited 
on the door and an assumed percent time off (``PTO'') value. As 
previously mentioned, in the September 2023 NOPR, DOE only considered 
one electrical component (i.e., the anti-sweat heat around the 
perimeter of the door leaf) in its representative units of manual non-
display doors for the engineering analysis. DOE also considered motors 
in its representative units of motorized non-display doors. However, 
DOE understands that other electricity-consuming devices could be 
installed on a non-display door, which are included in the calculation 
of DEC per the test procedure. As indicated by Kolpak in its comment, 
the current MDEC standards allow for additional electrical components 
such as heated vents, heated viewing windows, lights, and thermometer/
temperature alarms to be included and considered in the DEC 
calculation. However, the basis of the proposed energy conservation 
standards only accounts for the energy consumption from anti-sweat heat 
around the perimeter of the door (and motors for doors classified as 
motorized non-display doors). As a result, DOE understands that the 
proposed standards as outlined in the September 2023 NOPR may be 
difficult to meet for basic models of doors that have

[[Page 18557]]

additional electrical components beyond what DOE considered in its 
representative units.
    Also in response to the September 2023 NOPR, Senneca and Frank Door 
commented that DOE's method for complying with the new standards 
presume that all doors have certain features (e.g., lights) that can be 
adjusted to consume less energy, but that many doors do not have these 
features; thus, Senneca and Frank Door commented that DOE cannot 
conclude that new standards are technologically feasible by pointing to 
methods for compliance with the standards that are not available for 
all classes, types, and sizes of doors. (Senneca and Frank Door, No. 78 
at p. 3) DOE notes that for the September 2023 NOPR analysis, DOE did 
not consider lighting in its baseline representative units, and 
therefore did not consider any design options for reducing lighting 
energy consumption in the analysis. However, as indicated by Senneca 
and Frank Door, DOE recognizes that it cannot include all other 
possible electrical components in its baseline representative units and 
cannot analyze reduced energy consumption for other electrical 
components because not all doors contain these components.
    In light of these comments, DOE is considering equipment classes 
with maximum daily energy consumption allowances for non-display doors 
if manufacturers offer basic models with certain electricity-consuming 
devices as discussed in the following sections. This is similar to the 
approach used for the energy conservation standards for consumer 
refrigerators, refrigerator-freezers, and freezers. In a direct final 
rule relating to energy conservation standards for refrigerators, 
refrigerator-freezers, and freezers published on January 17, 2024, DOE 
established separate standards and separate product classes for 
products with multiple doors or specialty doors. The standards for 
those product classes (i.e., any product classes that implement special 
and multi-door designs) include energy allowances (i.e., specific 
increases in maximum allowable energy use) corresponding to the 
specific performance-related features (i.e., door-in-door designs, 
transparent doors, and multi-door designs). 89 FR 3026, 3028-3029.
    To develop the maximum daily energy consumption allowances specific 
for walk-in non-display doors with certain electrical components, DOE 
reviewed the data and calculations submitted by Kolpak, as well as 
product literature from hardware and instrument manufacturers. In its 
comment, Kolpak provided information regarding the following components 
that are included on its basic models of non-display doors: anti-sweat 
heat on viewing windows; lighting and mechanisms to turn the lighting 
on or off (e.g., manual toggle switches, door open timers, occupancy 
sensors); heated ventilators (also called heated pressure relief 
vents); and temperature alarms. (Kolpak, No. 66, Attachment 1 at pp. 1-
2) Kolpak provided information on model numbers of electrical 
components, rated wattage of those components, number of electrical 
components on its doors, and the calculation of the direct and indirect 
electrical energy consumption for all electrical components. (Kolpak, 
No. 66, Attachment 2) Using the detail provided by Kolpak, DOE also 
looked into the hardware and instrument manufacturers product offerings 
for electrical components to better understand the range of potential 
options for these additional electrical components. Based on this, DOE 
grouped the electrical components into four categories: lighting, anti-
sweat heat for viewing windows, digital temperature displays/alarms, 
and heated pressure relief vents. The underlying assumptions for each 
category of electrical components are described in the paragraphs that 
follow.
Lighting
    For the lighting category, DOE considered lighting, a night light, 
and a pilot light located on a switch to develop an appropriate DEC 
allowance for doors that have lighting. Lighting features provide 
valuable utility to consumers, namely visibility within the walk-in, 
particularly near the entrance and exit of the walk-in and is commonly 
controlled by a switch. Switches used for turning the lights on and off 
often have a pilot light so that the switch can be located in the dark. 
Additionally, as included in Kolpak's comment and calculations, a night 
light could also be attached to the walk-in door. Based on Kolpak's 
provided data and a review of product literature, DOE assumed lighting 
would have rated power of 13 W, a switch with a pilot light would have 
a rated power of 0.3 W, and a night light would have a rated power of 1 
W. DOE also assumed that these components would not be controlled by 
some demand-based controls, and therefore used the PTO values specified 
for lighting and other electricity-consuming devices without controls, 
timers, or auto-shut-off systems per table A.2 of appendix A along with 
the rated power to determine the direct electrical energy consumption. 
DOE assumed based on a review of product literature and doors it has 
tested that the light and night light would be located on the interior 
of the walk-in, and the switch may be located either interior or 
exterior to the walk-in. Therefore, all of the three components 
associated with lighting were conservatively assumed to be sited on the 
internal face of the door for the purposes of determining the indirect 
electrical energy consumption. See 10 CFR part 431, subpart R, appendix 
A, sections 6.3.2.2 and 6.3.3. Based on these assumptions, DOE 
calculated the MDEC allowances (i.e., the sum of the direct and 
indirect electrical energy consumption) for doors with lighting 
components which can be found in Table II.1. DOE notes that the 
lighting MDEC allowance would apply to doors with a light that may also 
have a night light and/or switch. Therefore, a door does not need to be 
equipped with all three components to use the allowance (i.e., a door 
with a light and a switch but no nightlight could use the allowance 
specified in Table II.1).
Anti-Sweat Heater for Viewing Window
    As previously mentioned, DOE included windows in its representative 
units of non-display doors. However, DOE did not consider additional 
anti-sweat heat specific to the window. Anti-sweat heaters are a 
performance-related feature used on viewing windows to prevent (1) 
condensation from collecting on the glass and (2) fogging of the glass. 
Kolpak commented that it is standard for medium-temperature non-display 
doors with viewing windows to have an anti-sweat heater wire around the 
frame of the window and for low-temperature non-display doors with 
viewing windows to have an anti-sweat heater wire and heated glass 
coating on the outer pane of glass. Kolpak commented that the widely 
used supplier used to provide a 10 W/ft anti-sweat heater wire without 
controls. Kolpak stated that it uses a 5 W/ft heater wire with controls 
in the frame of the viewport window. Kolpak stated that it cannot find 
additional means to reduce the energy consumption of the anti-sweat 
heater wire in the viewing window frame further. (Kolpak, No. 66 at p. 
1) Based on Kolpak's provided data and a review of product literature, 
DOE assumed that if anti-sweat heat is included around and/or on 
viewing windows, that anti-sweat heat would have rated power of 34 W 
for medium-temperature (i.e., cooler) applications and 84 W for low-
temperature (i.e., freezer) applications. DOE also assumed that these 
components would be controlled by some demand-based controls based on 
the information provided by Kolpak, and therefore DOE used the PTO 
values specified for anti-sweat heat with

[[Page 18558]]

controls, timers, or auto-shut-off systems per table A.2 of appendix A 
along with the rated power to determine the direct electrical energy 
consumption. DOE assumed that for the purposes of determining the 
indirect electrical energy consumption of the anti-sweat heater, 75-
percent of the total power is attributed to the interior and 25-percent 
of the total power is attributed to the exterior of the walk-in, 
consistent with the assumptions outlined in the DOE test procedure. See 
10 CFR part 431, subpart R, appendix A, sections 6.3.2.2 and 6.3.3. 
Based on these assumptions, DOE calculated the MDEC allowance (i.e., 
the sum of the direct and indirect electrical energy consumption) for 
doors with anti-sweat heat on their viewing windows, which can be found 
in Table II.1.
Digital Temperature Displays With or Without Alarms
    A digital temperature display provides utility in that it allows 
for users to easily monitor the temperature of the walk-in. The digital 
temperature display is connected to a thermocouple that measures the 
temperature of the walk-in and the interface on the exterior of the 
walk-in displays the temperature within the walk-in compartment. Based 
on review of product literature and Kolpak's data, DOE has determined 
that a digital temperature display could be paired with alarms or be 
standalone (i.e., without alarms). The alarms alert kitchen staff or 
others if the refrigerated goods within the walk-in compartment are in 
conditions that are too warm or too cold, which may spoil or ruin these 
goods. Additionally, alarms can sound if the walk-in door is left open 
for too long. Kolpak commented that walk-ins with multiple compartments 
that have only one exterior door but have doors on interior partitions 
that separate the compartments often have two temperature alarms on the 
exterior door so that the alarms can be heard by those outside of the 
walk-in. (Kolpak, No. 6, Attachment 1 at p. 2) Kolpak stated that the 
temperature alarm is typically rated at 4 W and Kolpak is unable to 
source a temperature alarm that has a lower rated power. (Id.) 
Additionally, through its review of hardware and instrument 
manufacturers product offerings, DOE identified that a panic or 
entrapment alarm could be installed for use in the event that a user is 
unable to exit the walk-in. Based on Kolpak's provided data and a 
review of hardware manufacturer product literature, DOE assumed a 
digital temperature display without alarms would have a rated power of 
2.4 W and a digital temperature display with alarms would have rated 
power of 4 W. In consideration of Kolpak's comment that a walk-in 
comprised of two compartments may require two temperature displays with 
alarms to be located on the exterior non-display door, DOE assumed that 
a digital temperature display with alarm(s) would have a total rated 
power of 8 W i.e., to reflect two digital temperature displays with 
alarms at 4 W each; an alternative approach could account for the power 
multiplied by the number of temperature displays with alarms present in 
the walk-in). DOE assumed based on a review of Kolpak's data and 
product literature that the digital temperature display with or without 
alarms would always be on, and as such used the PTO specified for other 
electricity-consuming devices without controls, timers, or auto-shut-
off systems per table A.2 of appendix A along with the rated power to 
determine the direct electrical energy consumption. The temperature 
display and alarms would likely be sited on the exterior of the walk-in 
door to be seen and heard, however, components of the display would be 
located interior to the walk-in, such as the thermocouple. Therefore, 
DOE conservatively assumed these components would be sited on both the 
internal and external face of the door for the purposes of determining 
the indirect electrical energy consumption. See 10 CFR part 431, 
subpart R, appendix A, sections 6.3.2.2 and 6.3.3. Based on these 
assumptions, DOE calculated the MDEC allowances (i.e., the sum of the 
direct and indirect electrical energy consumption) for doors with a (1) 
digital temperature display without an alarm or (2) digital temperature 
display with alarms. These calculated MDEC allowances can be found in 
Table II.1. DOE assumed that a door would either have one or the other, 
but would not have both (1) a digital temperature display without an 
alarm or (2) digital temperature display with alarms. As such, only one 
of these MDEC allowances would apply based on whether there is or is 
not an alarm connected to the digital temperature display.
Heated Pressure Relief Vent
    Heated ventilators, or heated pressure relief vents, are 
performance-related features that allow doors to open more easily when 
there is a pressure differential between the interior and the exterior 
of the walk-in. Kolpak commented that heated ventilators were not 
considered in DOE's analysis of non-display doors. Kolpak stated that 
some manufacturers put heated ventilators on a non-door panel so that 
they are not considered in the energy consumption calculation of a 
door, however, Kolpak places these devices on the door, where its 
energy consumption is captured in the daily energy consumption 
calculation. Kolpak commented that it uses the lowest wattage heated 
ventilator available. (Kolpak, No. 66 at p. 2) Kolpak's data indicates 
that a 4 W heated ventilator is used on doors for both medium-
temperature and low-temperature installations. DOE has tentatively 
determined, however, that while medium-temperature applications may 
require a pressure relief vent, it may not be necessary for the 
pressure relief vent to be heated. Therefore, DOE did not develop a 
MDEC allowance for medium-temperature non-display doors. Additionally, 
based on review of hardware manufacturer product literature and the 
recommendations for pressure relief vents based on the size of a walk-
in, DOE has tentatively determined that a heated pressure relief vent 
for a freezer could require up to 23 W of heat to prevent freezing and 
therefore provide sufficient airflow between the walk-in compartment 
and the exterior. DOE assumed based on a review of Kolpak's data and 
product literature that the heater component of the pressure relief 
vent would always be on, and as such used the PTO specified for other 
electricity-consuming devices without controls, timers, or auto-shut-
off systems per table A.2 of appendix A along with the rated power to 
determine the direct electrical energy consumption. Because the heated 
vent is located between both the exterior and interior of the walk-in, 
it is considered to be located interior to the walk-in for the purposes 
of determining the indirect electrical energy consumption. See 10 CFR 
part 431, subpart R, appendix A, sections 6.3.2.2 and 6.3.3. The MDEC 
allowance for low-temperature doors with heated pressure relief vents 
can be found in Table II.1.
Components Summary
    Table II.1 presents the MDEC allowances for lighting, anti-sweat 
heat for viewing windows, digital temperature displays/alarms, and 
heated pressure relief vents, as described in the previous sections.

[[Page 18559]]



           Table II.1--Maximum Daily Energy Consumption Allowances and Assumptions for Each Component
----------------------------------------------------------------------------------------------------------------
                                                                                       MDEC            MDEC
                                   Wattage of                                       allowance--     allowance--
             Device               component(s)    Controls (Y/N)     Location         medium-          low-
                                       (W)                                          temperature     temperature
                                                                                     (kWh/day)       (kWh/day)
----------------------------------------------------------------------------------------------------------------
Door light, night light, and/or            14.3  No.............  Interior......            0.33            0.40
 switch.
Heated viewing window: Cooler                34  Yes............  Interior......            0.25  ..............
 Freezer.
Heated viewing window--freezer.              84  Yes............  Interior......  ..............            1.42
Digital temperature without                 2.4  No.............  Interior......            0.07            0.09
 alarm.
Digital temperature display                   8  No.............  Interior......            0.24            0.30
 with alarm.
Heated vent--freezer only......              23  No.............  Interior......  ..............            0.85
----------------------------------------------------------------------------------------------------------------

    As discussed in the preceding paragraphs, each of these electrical 
components provide some consumer utility when installed on a non-
display door. Additionally, having these electrical components 
installed on the door limits the number of electrical connections that 
need to be wired when installing a walk-in. Pursuant to EPCA, DOE may 
establish separate standards for a group of covered equipment (i.e., 
establish a separate equipment class) if DOE determines that separate 
standards are justified based on the type of energy used or if DOE 
determines that the equipment's capacity or other performance-related 
feature justifies a different standard. (42 U.S.C. 6316(a); 42 U.S.C. 
6295(q)(1)(B)) DOE has tentatively determined that that the devices it 
has listed previously constitute a performance-related feature that 
justify a higher standard. DOE notes that the information described 
previously and in Table II.1 was used to develop the MDEC allowances 
for basic models of non-display doors that have any number of these 
components. However, DOE notes that for the purposes of determining DEC 
in accordance with the Federal test procedure at appendix A, 
manufacturers must follow the instructions for calculating both direct 
and indirect electrical energy consumption of components as described 
in appendix A.
    DOE reviewed non-public manufacturer data submitted to DOE's 
Compliance Certification Management System Database (``CCD'') to 
estimate the percentage of the market that includes these other 
electricity consuming devices on non-display doors. DOE's estimates of 
shipments containing electricity consuming devices are shown in Table 
II.2.

        Table II.2--Percentage of Non-Display Door Shipments Containing Each Electricity Consuming Device
----------------------------------------------------------------------------------------------------------------
                                                                Percent of shipments with component
                                                 ---------------------------------------------------------------
                    Component                         Medium-          Low-           Medium-          Low-
                                                   temperature,    temperature,    temperature,    temperature,
                                                    manual (%)      manual (%)     motorized (%)   motorized (%)
----------------------------------------------------------------------------------------------------------------
Lighting........................................              10               6              22              33
Viewing Window ASH..............................               4               1               4               3
All Other Electrical Components.................               8               8              28              73
----------------------------------------------------------------------------------------------------------------

    DOE requests comment on the MDEC allowances for the specified 
electricity consuming devices. Additionally, DOE requests comment on 
the assumed wattages, presence or absence of controls, and location 
that were considered in the calculation of MDEC allowances for the 
specified electricity consuming devices.
    The analytical results (i.e., LCC, PBP, and NIA) presented in 
section II.C of this document account for the updates discussed in this 
section.
b. Adjustment of U-Factors and Resulting Thermal Load
    The DOE test procedure requires that the total non-display door 
energy is calculated by summing (1) the total daily energy consumption 
due to thermal conduction load through the door (i.e., the additional 
refrigeration energy consumption to overcome conduction through the 
door), (2) total daily direct electrical energy consumption (i.e., the 
energy consumed by electrical components sited on the door), and (3) 
the total daily indirect electrical energy consumption (i.e., the 
additional refrigeration energy consumption due to thermal output into 
the walk-in from electrical components contained on the inside face of 
the door). See 10 CFR part 431, subpart R, appendix A, section 6.3.4. 
The energy consumption due to thermal conduction load is based on an 
assumed temperature difference between the interior and exterior of the 
walk-in, an assumed refrigeration system energy efficiency ratio 
(``EER''), and the U-factor and size of the door. Improvements to the 
design and/or materials of the door and its frame could result in a 
decreased thermal load.
    At the proposed standard level in the September 2023 NOPR, DOE 
assumed that all manual-opening non-display doors would need to 
implement anti-sweat heater controls, improved framing systems, and 
reduced anti-sweat heat. 88 FR 60746, 60845. As discussed in the 
September 2023 NOPR TSD, DOE determined U-factors for each 
representative door size by scaling the U-factors determined from 
tested non-display doors based on theoretical U-factors. DOE also 
assumed each non-display door had a window sized at 2 ft\2\. Wood 
frames are the least efficient framing material currently found on the 
market and were selected as the baseline framing material. High-density 
polyurethane door frames are more thermally insulative and were 
selected as the improved framing material. See section 5.7.1.3 of the 
September NOPR TSD. In response to the September 2023 NOPR, Kolpak 
commented that it uses low-density, high-insulation foam core material 
in its frame, which has better insulation than wood or high-density

[[Page 18560]]

foam. (Kolpak, No. 66 at p. 2) Therefore, DOE would expect that the 
thermal load at the proposed level to be consistent with or greater 
than the thermal load in the Kolpak data.
    In the data provided by Kolpak there are U-factor test results for 
both medium-temperature and low-temperature non-display doors of 
various sizes with and without a window. (Kolpak, No. 66 Attachment 2) 
For medium-temperature doors, DOE found that the thermal conduction 
load at the proposed energy conservation standard level from the 
September 2023 NOPR is consistent with the thermal conduction load 
calculated from the data provided by Kolpak data. For low-temperature 
doors, DOE found that the thermal conduction load at the proposed 
energy conservation standard level from the September 2023 NOPR was 
lower than the thermal conduction load calculated from the data 
provided by Kolpak data. To further evaluate thermal conduction load 
for both medium-temperature and low-temperature non-display doors, DOE 
further reviewed additional non-public manufacturer data submitted to 
DOE's Compliance Certification Management System Database (``CCD''). 
Manufacturers are not currently required to certify the U-factor or 
thermal conduction load to the CCD; however, they are required to 
certify the rated power of each light, heater wire, and/or other 
electricity consuming device associated with each basic model and 
whether such device(s) has a timer, control system, or other demand-
based control reducing the device's power consumption. See 10 CFR 
429.53(b)(4)(i). Using the certified data, DOE back-calculated the 
thermal load and ultimately U-factor for multiple basic models of 
medium-temperature and low-temperature non-display doors. DOE verified 
these back-calculated U-factors with its own test data. DOE compared 
the thermal conduction load by non-display door area (AND) 
of (1) Kolpak's data, (2) any back-calculated data from the CCD that 
has been verified with test data, (3) data received during confidential 
manufacturer interviews, and (4) test data, with the thermal load by 
non-display door area for each representative unit and efficiency level 
with a different door construction design (and thus different thermal 
conduction load) from the September 2023 NOPR. DOE is posting a 
supplementary file that contains supplementary information to support 
the analysis provided in this NODA (referred to as the ``NODA support 
document'').\6\ The updated thermal conduction load for low-temperature 
non-display doors is shown in Figure 4.1 of the NODA support document 
that has been posted to the docket. Additionally, the updated energy 
consumption values for low-temperature non-display doors that reflect 
the U-factor and resulting thermal load update can be found in section 
2 of the NODA support document. Note that these energy consumption 
values do not account for any of the MDEC allowances.
---------------------------------------------------------------------------

    \6\ The NODA support document can be found in the docket at 
www.regulations.gov/document/EERE-2017-BT-STD-0009.
---------------------------------------------------------------------------

    For low-temperature applications, DOE has tentatively determined 
that the thermal conduction load by area for low-temperature 
applications in the proposed standard level from the September 2023 
NOPR is lower than that calculated using the data DOE evaluated for 
this NODA. Therefore, DOE increased the U-factors for each 
representative unit of low-temperature non-display doors by 9-percent 
for this NODA. DOE has tentatively determined that this increase in U-
factor would be more representative of the low-temperature non-display 
doors currently on the market.
    DOE requests comment on representativeness of the adjustments made 
to the U-factors for the low-temperature non-display doors.
    The analytical results (i.e., LCC, PBP, and NIA) presented in 
section II.C of this document account for the updates discussed in this 
section.
2. Dedicated Condensing Units and Single-Packaged Dedicated Systems
a. More Efficient Single Speed Compressors
    In the September 2023 NOPR, DOE analyzed higher-efficiency 
compressors for dedicated condensing units and single-packaged 
dedicated systems. The higher-efficiency compressor design options 
included both higher-efficiency single-speed compressors and variable-
speed compressors. For single-packaged dedicated systems, DOE 
considered both higher-efficiency single-speed compressors and 
variable-speed compressors in the September 2023 NOPR. However, DOE did 
not consider higher-efficiency single-speed compressors for dedicated 
condensing units in the September 2023 NOPR. See section 5.7.2.1 of the 
September 2023 NOPR TSD for further discussion.
    In response to the September 2023 NOPR, the Efficiency Advocates 
recommended that DOE analyze improved single-speed compressor 
efficiency as a design option. (Efficiency Advocates, No. 77 at p. 2) 
The Efficiency Advocates stated that there is a range of single-speed 
compressor efficiencies available even when selecting for a given 
compressor type, capacity, input voltage, power supply, and 
refrigerant. (Id. at p. 2)
    The CA IOUs recommended that DOE consider two single-speed 
compressor efficiencies (i.e., CMP1 and CMP2) as design options for 
dedicated condensing units. (CA IOUs, No. 76 at pp. 8-9) The CA IOUs 
stated that the compressor manufacturers Copeland and Bitzer offer two 
or three more compressor options with different efficiencies at each 
size and temperature application and that therefore CMP1 and CMP2 are 
justified as design options. (Id. at pp. 8-9)
    In response to the comments received, DOE reviewed publicly 
available compressor performance data for both medium-temperature and 
low-temperature walk-in applications. DOE specifically collected data 
for compressors applicable to the range of representative capacities 
analyzed for dedicated condensing units in the September 2023 NOPR.\7\ 
For this NODA analysis, DOE only considered single-speed compressors 
compatible with R-448A that are rated at the DOE walk-in test 
conditions and available for the North American walk-in market.\8\ DOE 
excluded from consideration any compressors that may negatively impact 
consumer utility--e.g., DOE did not consider three-phase compressors 
when there were options for both single- and three-phase compressors at 
a given capacity, as some buildings where walk-ins are installed may 
not have the necessary three-phase power. Additionally, as discussed in 
section 5.7.2.1 of the September 2023 NOPR TSD, during interviews 
manufacturers highlighted utility concerns related to customer 
preference for specific compressor types (e.g., scroll, semi-hermetic, 
etc.). Therefore, when evaluating higher-efficiency single-speed 
compressors for this NODA, DOE selected the highest compressor 
efficiency that would still allow for consumer choice between scroll 
and semi-hermetic compressors if both compressor types were available 
at the given representative capacity. DOE notes that it cannot verify 
that the

[[Page 18561]]

compressor data provided by the CA IOUs and Efficiency Advocates in 
their respective comments are representative of compressors rated at 
DOE walk-in test conditions. Additionally, the compressors provided may 
impact utility because there are both scroll and semi-hermetic types. 
Therefore, DOE did not evaluate the compressors provided in the 
comments from the CA IOUs and Efficiency Advocates. However, using the 
criteria described for reviewing publicly available compressor data, 
DOE identified single-speed compressors with capacities roughly between 
50 and 60 kBtu/h that have higher efficiencies than the compressor in 
that capacity range used in the September 2023 NOPR analysis. 
Compressors in this capacity range could be used in the DC.M.O.054, 
DC.M.I.054, and DC.M.O.124 representative units.\9\ DOE did not 
identify any higher efficiency single-speed compressors for low-
temperature applications at the representative capacities analyzed 
based on the criteria previously mentioned.
---------------------------------------------------------------------------

    \7\ These capacities are as follows: 9 kBtu/h, 25 kBtu/h, 54 
kBtu/h, 75 kBtu/h, and 124 kBtu/h for medium-temperature dedicated 
condensing units; 3 kBtu/h, 9 kBtu/h, 54 kBtu/h, 75 kBtu/h for low-
temperature dedicated condensing units.
    \8\ For a discussion of DOE's tentative conclusions regarding 
the appropriateness of setting standards based upon models operating 
with R-448A, see 88 FR 60746, 60771.
    \9\ DOE used two compressors with capacities between 50 and 60 
kBtu/h for the 124 kBtu/h medium-temperature outdoor dedicated 
condensing unit. DOE determined that this would be representative 
for units of this capacity.
---------------------------------------------------------------------------

    As such, DOE determined that a higher-efficiency single-speed 
compressor design option could be applied to the following 
representative units: DC.M.O.054, DC.M.I.054, and DC.M.O.124. In this 
NODA, DOE presents an updated analysis when considering the additional 
compressor design option for these three representative units.
    In its updated analysis, DOE added an efficiency level (``EL'') 
which corresponds to the higher-efficiency single-speed compressor 
design option for the three representative units mentioned previously. 
The higher-efficiency single-speed compressor has an EER for walk-in 
refrigeration systems of 7.62 Btu/(W-h), which is 5 percent greater 
than the baseline compressor's EER of 7.25 Btu/(W-h).\10\ Similar to 
the NOPR analysis, DOE ordered the design options for each 
representative unit in terms of decreasing cost-effectiveness 
(manufacturer production cost differential/AWEF2 differential). Table 
3.1 of the NODA support document describes the design option codes 
related to the refrigeration system representative units analyzed in 
this NODA. The higher-efficiency single-speed compressor was added at 
EL 1 for the DC.M.I.054 representative unit and at EL 3 for both 
DC.M.O.054 and DC.M.O.124 representative units. As a result, the design 
options that are used at ELs after the higher-efficiency single-speed 
compressor design option are now associated with one EL higher than in 
the September 2023 NOPR. For example, in the September 2023 NOPR, 
electronically commutated (``EC'') condenser fan motors were 
implemented at EL 1 for the DC.M.I.054 Because the higher-efficiency 
single-speed compressor design option was implemented at EL 1 in this 
NODA analysis, the EC condenser fan motor design option is implemented 
at EL 2 for this representative unit.
---------------------------------------------------------------------------

    \10\ DOE determined compressor performance using conditions 
representative of the A condition test specified by the DOE test 
procedure for walk-in refrigeration systems in appendix C1 to 
subpart R of 10 CFR part 431. The test conditions used to determine 
compressor performance were as follows: a return gas temperature of 
41 [deg]F, an evaporator dewpoint temperature of 23 [deg]F, and a 
condenser dewpoint temperature of 120 [deg]F.
---------------------------------------------------------------------------

    Section 3 of the NODA support document shows the cost-efficiency 
results from the September 2023 NOPR, which were published in appendix 
5A of the September 2023 NOPR TSD,\11\ and the updated cost-efficiency 
results with the additional compressor design option EL. The tables 
show the AWEF2, manufacturer production cost (``MPC''), and 
manufacturer selling price (``MSP'') plus shipping costs associated 
with each EL. DOE notes that due to the interaction between design 
options in the engineering analysis, the performance increase and/or 
incremental MPC associated with design options added after the higher-
efficiency single-speed compressor design option differ from those 
presented in the NOPR analysis.
---------------------------------------------------------------------------

    \11\ DOE notes that in appendix 5A of the September 2023 NOPR 
TSD, the tables label the efficiency values in terms of AWEF, 
however, they are in terms of AWEF2 and should have been labeled as 
such.
---------------------------------------------------------------------------

    DOE requests comment on the updated cost-efficiency results for the 
54 kBtu/h indoor and outdoor medium-temperature dedicated condensing 
units and 124 kBtu/h outdoor medium-temperature dedicated condensing 
unit presented in section 3 of the NODA support document.
    The analytical results (i.e., LCC, PBP, and NIA) presented in 
section II.C of this document account for the updates discussed in this 
section.
b. Off-Cycle Ancillary Power
    Based on test data available at the time, in the September 2023 
NOPR analysis DOE tentatively determined that the only source of off-
cycle power for dedicated condensing units and single-packaged 
dedicated systems would be crankcase heater power. See section 5.6.3.3 
of the September 2023 NOPR TSD. DOE assumed that the off-cycle 
crankcase heater power would be the same for both medium-temperature 
and low-temperature applications, which DOE estimated using crankcase 
heater wattage specifications from compressor manufacturer product 
literature.
    In response to the September 2023 NOPR, AHRI and Hussmann commented 
that there are potential sources of off-cycle ancillary power that DOE 
did not account for and should consider, such as standard operating 
controls, defrost time clocks, digital controllers, and transformers. 
(AHRI, No. 72 at p. 19; Hussmann, No. 75 at p. 9)
    In response to these comments, DOE analyzed additional test data 
and compared the tested off-cycle power values to the crankcase heater 
wattages specified by compressor manufacturers. DOE found that for 
medium-temperature dedicated condensing units, the assumed crankcase 
heater wattage used in the NOPR analysis matched both the tested off-
cycle power values and the compressor manufacturer-specified wattages. 
Therefore, DOE has tentatively determined that the assumed crankcase 
heater wattages used to analyze medium-temperature dedicated condensing 
units and single-packaged dedicated systems in the NOPR analysis are 
representative of the entire off-cycle power of such units.
    For low-temperature dedicated condensing units, DOE found that the 
off-cycle power test data was up to 5 Watts greater than the compressor 
manufacturer-specified crankcase heater wattages, indicating there may 
be additional sources of off-cycle power other than the crankcase 
heater. Additionally for low-temperature units, DOE found that the 
compressor manufacturer-specified crankcase heater wattages at a given 
capacity range were slightly different than those specified for medium-
temperature units. Therefore, for this NODA, DOE adjusted the assumed 
crankcase heater wattages for low-temperature dedicated condensing 
units and single-packaged dedicated systems, as shown in table II.2 and 
table II.3. DOE also added 5 Watts of off-cycle ancillary power not 
associated with crankcase heater power for all low-temperature 
dedicated condensing units and single-packaged dedicated systems. Both 
changes can be seen in the updated refrigeration engineering analysis 
spreadsheet.\12\ As

[[Page 18562]]

indicated by commenters, DOE suspects that this additional 5 Watts of 
power is attributed to timers and controls associated with defrost 
cycles.
---------------------------------------------------------------------------

    \12\ The updated refrigeration systems engineering sheet can be 
found in the docket for this rulemaking at www.regulations.gov/docket/EERE-2017-BT-STD-0009.

    Table II.3--Crankcase Heater Power (W) for Low-Temperature Refrigeration Systems From September 2023 NOPR
----------------------------------------------------------------------------------------------------------------
                                                                 Refrigeration system capacity
                                             -------------------------------------------------------------------
               Compressor type                                  >=10,000 and      >=50,000-        >=100,000-
                                               <10,000 Btu/h   <50,000 Btu/h    <100,000 Btu/h   <200,000 Btu/h
----------------------------------------------------------------------------------------------------------------
Hermetic....................................              40
Scroll......................................              40               67               90               100
Semi-Hermetic...............................              40               50               70               100
Rotary......................................              27
----------------------------------------------------------------------------------------------------------------


     Table II.4--Updated Crankcase Heater Power (W) for Low-Temperature Refrigeration Systems for This NODA
----------------------------------------------------------------------------------------------------------------
                                                                 Refrigeration system capacity
                                             -------------------------------------------------------------------
               Compressor type                                    >=5,000-        >=20,000-         >=50,000-
                                               <5,000 Btu/h    <20,000 Btu/h    <50,000 Btu/h    <200,000 Btu/h
----------------------------------------------------------------------------------------------------------------
Hermetic....................................              40
Scroll......................................              40               70               73               100
Semi-Hermetic...............................              40               50               70               100
Rotary......................................              27
----------------------------------------------------------------------------------------------------------------

    DOE requests comment on the updated crankcase heater wattages and 
additional off-cycle ancillary power for low-temperature dedicated 
condensing units and single-packaged dedicated systems.
    The analytical results (i.e., LCC, PBP, and NIA) presented in 
section II.C of this document account for the updates discussed in this 
section.
c. Low GWP Refrigerant Transition
    As discussed in the September 2023 NOPR, the Environmental 
Protection Agency (``EPA'') published a NOPR, ``Phasedown of 
Hydrofluorocarbons: Restrictions on the Use of Certain 
Hydrofluorocarbons Under Subsection (i) the American Innovation and 
Manufacturing Act of 2020'', on December 15, 2022, as a part of the 
American Innovation and Manufacturing (``AIM'') Act, which outlined new 
refrigerant regulations regarding acceptable global warming potential 
(``GWP'') limits for various air conditioning and refrigeration 
systems. 87 FR 76738. On October 24, 2023, EPA finalized these 
proposals (``October 2023 AIM Act Final Rule''). 88 FR 73098. The 
October 2023 AIM Act Final Rule established (effective January 1, 2026) 
a limit of 300 GWP for remote condensing units in retail food 
refrigeration systems and cold storage warehouses with less than 200 
lbs of charge, which includes split-system walk-in refrigeration 
systems covered under the scope of the September 2023 NOPR. 88 FR 
73098, 73209. In the September 2023 NOPR, DOE analyzed R-454A and R-
455A refrigerants which have GWPs less than 300 and tentatively 
determined that R-454A would be the most likely replacement refrigerant 
for medium- and low-temperature walk-in refrigeration systems once the 
regulations finalized in the October 2023 AIM Act Final Rule take 
effect. DOE also tentatively determined that R-454A would have 
comparable performance to the currently-used refrigerant R-448A. 88 FR 
60746, 60772. As there was limited compressor performance data 
available for R-454A at the time, DOE used R-448A as the basis for its 
engineering analysis for medium- and low-temperature dedicated 
condensing units and single-packaged dedicated systems.\13\ Id. In the 
September 2023 NOPR, DOE requested performance data for walk-in 
refrigeration systems using R-454A, R-454C, and/or R-455A. DOE also 
sought comment on its tentative determinations that R-454A is the most 
likely replacement for the current refrigerants being used (i.e., R-
448A and R-449A) and that walk-in dedicated condensing systems would 
not suffer a performance penalty when switching from R-448A or R-449A 
to R-454A. Id.
---------------------------------------------------------------------------

    \13\ DOE notes that a more efficient single-speed compressor 
that used propane was analyzed as a design option for some single-
packaged dedicated systems. A propane compressor was analyzed if the 
charge limit for propane was sufficient to provide the analyzed 
capacity and the propane compressor resulted in increased 
efficiency.
---------------------------------------------------------------------------

    In response, AHRI, Lennox, and Hussmann commented that R-454A is 
comparable in performance to R-448A but that it is not the most likely 
low-GWP replacement for WICFs because R-454A has a GWP above 150. 
(AHRI, No. 72 at p. 10; Lennox, No. 70 at pp. 6-7; Hussmann, No. 75 at 
p. 10) AHRI and Lennox recommended that modeling should instead be 
conducted using R-454C and/or R-455A since California and Washington 
state regulations prohibit the use of a refrigerant with a GWP greater 
than 150 for systems with more than 50 lbs. of refrigerant charge. 
(AHRI, No. 72 at p. 10; Lennox, No. 70 at pp. 6-7) Hussmann and NRAC 
commented that there may be some states with stricter regulations than 
the EPA that may not allow refrigerants above 150 GWP. (Hussmann, No. 
75 at p. 10; NRAC, No. 73 at p. 2)
    DOE acknowledges that certain localities already require, or may 
require in the future, WICF refrigeration systems to be designed for 
use with sub-150 GWP refrigerants.\14\ Based on analysis of low-GWP 
refrigerant performance in walk-in refrigeration systems conducted for 
the September

[[Page 18563]]

2023 NOPR, DOE has tentatively concluded that the highest performing 
sub-150 GWP refrigerant appropriate for use in split-system walk-in 
refrigeration systems is R-454C. See section 5.6.3.1 of the September 
2023 NOPR TSD. To assess the potential impact of state level sub-150 
GWP requirements, DOE reviewed the EERs of R-454C compressors with 
capacities representative of walk-in refrigeration systems and compared 
these EERs to those of the baseline compressors analyzed in the 
September 2023 NOPR. DOE determined the R-454C EERs at operating 
conditions representative for the A test conditions prescribed in the 
DOE test procedure for walk-in refrigeration systems, adjusting the 
condensing dewpoint up 2 [deg]F to account for the higher refrigerant 
temperature glide of R-454C as compared to R-448A or R-454A.
---------------------------------------------------------------------------

    \14\ California established (effective January 1, 2022) a limit 
of 150 GWP for retail food refrigeration equipment and cold storage 
warehouses with less than 50 lbs of charge. Washington is expected 
to establish a limit of 150 GWP for retail food refrigeration 
equipment and cold storage warehouses with less than 50 lbs of 
charge.
---------------------------------------------------------------------------

    DOE found that trends in the R-454C compressor efficiencies 
generally aligned with the compressor EERs used in the September 2023 
NOPR analysis, except for the DC.M.O.025 and DC.M.I.025 representative 
units. At this 25 kBtu/h capacity DOE found that the available R-454C 
compressor had an EER that is 4 percent less than that of the 
compressor analyzed in the September 2023 NOPR. Based on this, DOE 
determined that using the R-454C compressor analyzed could result in an 
AWEF2 that is 2 percent lower for 25 kBtu/h medium-temperature 
dedicated condensing units than a comparable unit using an R-454A-
compatible compressor. As such, and in the absence of more efficient 
compressors of the same type compatible with R-454C, DOE has 
tentatively determined that to achieve the standard proposed in the 
September 2023 NOPR (based on the performance of R-448A), a medium-
temperature walk-in refrigeration system using a sub-150 GWP 
refrigerant may need to incorporate additional design options beyond 
what DOE presumed in the September 2023 NOPR. To determine the cost of 
these additional design options DOE constructed the cost curves 
corresponding to use of the R-454C compressor (with roughly 2-percent 
reduction of AWEF2 for each evaluated design) and calculated additional 
cost to attain the proposed AWEF2 by interpolating along the cost-
efficiency curves. Based on this analysis DOE has tentatively 
determined that additional MSP required to achieve the proposed AWEF2 
for less-than-150 GWP refrigerant would be $381 for 25 kBtu/h medium 
temperature indoor dedicated condensing units and $96 for 25 kBtu/h 
medium temperature outdoor dedicated condensing units.
    DOE requests comment on the estimated additional MPC associated 
with 25 kBtu/h medium temperature indoor and outdoor dedicated 
condensing units achieving the proposed AWEF2 standard levels while 
operating with a refrigerant with less than 150 GWP.
    The analytical results (i.e., LCC, PBP, and NIA) presented in 
section II.C account for the cost adder presented in this section, as 
described in section II.C.1.a of this document.
d. Miscellaneous Updates to the Engineering Analysis Spreadsheet
    In response to the September 2023 NOPR, stakeholders commented that 
there were several issues with calculations in the refrigeration 
systems engineering spreadsheet.\15\ AHRI and Hussmann suggested 
several corrections to the engineering spreadsheet. (AHRI, No. 72 at 
pp. 17-19; Hussmann, No. 75 at pp. 7-9) DOE also identified several 
issues not prompted by comments. DOE discusses the corrections that it 
made in this NODA in the following paragraphs. To the extent that 
stakeholders made comments on the engineering spreadsheet and DOE has 
determined that updates to the spreadsheet are not necessary, DOE will 
address those comments in a subsequent rulemaking.
---------------------------------------------------------------------------

    \15\ The September 2023 NOPR refrigeration systems engineering 
sheet can be found at www.regulations.gov/docket/EERE-2017-BT-STD-0009-0052.
---------------------------------------------------------------------------

    AHRI and Hussmann commented that row 77 for the condenser and row 
86 for the evaporator on the `Calculation' tab were calculating 
pressures at the incorrect point of the refrigeration cycle, claiming 
that all subsequent calculations use the wrong pressures. (AHRI, No. 72 
at pp. 17-18; Hussmann, No. 75 at pp. 7-8) DOE notes that the 
calculations in question are used only for determination of refrigerant 
glide to adjust from midpoint to dewpoint. The errors in these 
adjustments result in roughly 0.1 [deg]F difference in calculated dew 
point temperature for the condenser. They result in zero difference in 
evaporator dew point temperature for dedicated condensing unit 
calculations (for which evaporator dew point temperature is prescribed 
by the test procedure) and roughly 0.03 [deg]F difference for single-
packaged dedicated systems calculations. These differences make no 
significant impact on overall results. Nevertheless, DOE has revised 
the calculations for this NODA such that the calculation will be based 
on a quality of 0.5 for the condenser, which is representative of the 
condenser midpoint, and a quality for the evaporator somewhat greater 
than 0.5 to account for the fact that evaporator refrigerant inlet 
quality is non-zero.
    AHRI and Hussmann commented that in rows 165 and 233 of the 
`Calculations' tab, which contain the condenser half glide calculation 
for B and C conditions, the formula is using a temperature input rather 
than a pressure input to calculate a temperature output. (AHRI, No. 72 
at pp. 18-19; Hussmann, No. 75 at p. 9). This calculation results in 
overestimation of the dew point by roughly 0.5 [deg]F, and a 
corresponding slight overestimation of compressor energy use. DOE has 
revised this calculation for this NODA.
    In the September 2023 NOPR, the cost of additional spark-proofing 
electronic components was not properly accounted for due to an 
incorrect formula. In the updated refrigeration system engineering 
analysis spreadsheet, DOE updated the compressor cost calculation 
(which feeds into the MPC) to include the additional costs for spark-
proofing electronic components for single-packaged dedicated systems 
that use propane as the refrigerant. As a result of this change in MPC 
associated with propane-compatible compressors, DOE reordered the 
design options of the SP.M.O.002 and SP.M.I.002 representative units 
such that the design options are ordered from most cost-effective AWEF2 
improvements to the least cost-effective AWEF2 improvements, where 
cost-effectiveness is based on the ratio of AWEF2 increase to MPC 
increase.
    In the September 2023 NOPR, all the high-temperature, 2 kBtu/h and 
7 kBtu/h, outdoor single-packaged dedicated system representative units 
implemented the variable-speed condenser fan design option before the 
electronically commutated motor design option was implemented. However, 
an electronically commutated motor is a prerequisite for the variable-
speed condenser fan design option. In the updated refrigeration system 
engineering spreadsheet, DOE reordered the variable-speed condenser fan 
and electronically commutated motor design options for these 
representative units. DOE notes that reordering these design options 
did not impact the results of the proposed efficiency level as both 
design options were included in the efficiency level corresponding to 
the proposed standard level.
    Additionally, DOE updated the calculation of the enthalpy exiting 
the unit cooler that is used in the calculation of the gross capacity 
for

[[Page 18564]]

dedicated condensing units to be consistent with the DOE test 
procedure. See section C7.5.2 of American National Standards Institute/
Air-Conditioning, Heating, and Refrigeration Institute Standard 1250 
(I-P), ``2020 Standard for Performance Rating of Walk-in Coolers and 
Freezers''. The calculation for the enthalpy exiting the unit cooler 
for single-packaged dedicated systems was consistent with the DOE test 
procedure for the NOPR analysis and therefore, DOE did not update it 
for single-packaged dedicated systems for this NODA.
    Overall, the updates made to the engineering analysis spreadsheet 
resulted in a minimal change to the cost-efficiency curves for each 
representative unit. Comparing efficiency levels with the same design 
option combinations for each representative unit between the September 
2023 NOPR and this NODA, the AWEF2s generally increased or decreased 
between 1- and 3-percent as a result of the changes discussed 
previously. Similarly, in this NODA, design option order generally 
remained as it was in the NOPR, and manufacturer production costs did 
not change from the NOPR for many representative units. However, in 
some cases, changes in representative unit performance at the baseline 
required re-baselining to meet the current energy conservation 
standards. This re-baselining resulted in slightly different 
combinations of design options at the baseline efficiency level for the 
following representative units, which also resulted in either more or 
fewer design options above baseline depending on whether the baseline 
efficiency level needed fewer or more design options at the baseline to 
meet the current AWEF standards: DC.M.O.009, DC.M.I.025, DC.L.O.075, 
and SP.L.I.006. Additionally, some of the changes to the engineering 
spreadsheet impacted cost model inputs (e.g., fan motor horsepower 
impacts the cost of a fan motor); therefore, there are slight changes 
to the manufacturer production costs associated with some 
representative units' efficiency levels even if the design option order 
has not changed from the September 2023 NOPR analysis. This was the 
case for the following representative units: DC.M.O.009, DC.M.O.025, 
DC.M.O.054, DC.M.O.075, DC.M.O.124, DC.M.I.009, DC.M.I.025, DC.M.I.054, 
DC.M.I.075, DC.L.O.003, DC.L.O.009, DC.L.O.025, DC.L.O.054, DC.L.I.003, 
DC.L.I.009, DC.L.I.025, DC.L.I.054, SP.L.O.002, and SP.L.I.002.
    See section 3 of the NODA support document for updated cost-
efficiency results. The analytical results (i.e., LCC, PBP, and NIA) 
presented in section II.C of this document account for the updates 
discussed in this section.
3. Unit Coolers
a. Cost Assumptions at Max-Tech Efficiency Levels
    In the September 2023 NOPR, using the Unit Cooler Performance 
Database \16\ DOE developed linear cost-efficiency correlations for 
each representative unit, which DOE used to determine the MPC increase 
from the baseline efficiency level to the higher efficiency levels for 
unit coolers. See section 5.8.6 of the September 2023 NOPR TSD. When 
building the Unit Cooler Performance Database, DOE did not consider 
that adding additional rows to the unit cooler heat exchanger would 
require an increase in cabinet size when determining the MPCs 
associated with each efficiency level. DOE based this assumption on 
manufacturers' unit cooler product catalogs, which included unit cooler 
case dimensions.
---------------------------------------------------------------------------

    \16\ The Unit Cooler Performance Database can be found at 
www.regulations.gov/document/EERE-2017-BT-STD-0009-0064.
---------------------------------------------------------------------------

    In response, Lennox stated that increasing 4-row unit cooler 
designs to 5- or 6-row designs is not cost-effective because adding 
coil rows has diminishing returns on improved efficiency and would 
result in increased coil face area and increased cabinet size. (Lennox, 
No. 70 at p. 4) AHRI, Hussmann, and Lennox commented that current unit 
cooler coil and cabinet designs are optimized around 4-row designs and 
increasing efficiency would be more costly than what DOE estimated when 
considering packaging, freight, materials, and scrap. (AHRI, No. 72 at 
pp. 3-4, 9; Hussmann, No. 75 at pp. 2, 12; Lennox, No. 70 at p. 4) \17\
---------------------------------------------------------------------------

    \17\ DOE notes that it also received comments indicating that 
the conversion costs for refrigeration systems should be 
incorporated as an amortized consideration in the MSP. DOE will 
consider and address these stakeholder comments in a subsequent 
rulemaking.
---------------------------------------------------------------------------

    During the development of the September 2023 NOPR analysis, DOE 
identified several manufacturers producing unit coolers with heat 
exchangers 5 or more rows deep. However, DOE acknowledges the concerns 
of AHRI, Lennox, and Hussmann that some manufacturers may not be 
currently producing unit coolers with heat exchangers 5 rows deep. As 
such, these manufacturers may need to expand the cabinet size of their 
4-row unit coolers to accommodate larger heat exchangers (i.e., 
evaporator coils with at least 5 rows). In response to this feedback, 
DOE updated its analysis for this NODA and assumed that the unit cooler 
case would have to be expanded to accommodate an additional row at the 
maximum technology (``max-tech'') efficiency level for every unit 
cooler representative unit.
    DOE estimated the additional MPC using the same cost modeling 
processes described in section 5.4 of the September 2023 NOPR TSD. The 
additional MPC includes additional material, scrap, and packaging 
associated with the cabinet size increase. DOE developed this 
additional MPC for expanding unit cooler case size for several 
representative units. The average cost adder associated with the 
cabinet size increase was $11 for the representative capacities DOE 
analyzed. Updated unit cooler cost efficiency curves can be found in 
section 3 of the NODA support document.
    DOE has tentatively determined that the increase in shipping cost 
would not significantly affect the analysis and therefore, did not 
include this in the revised analysis in this NODA.
    The analytical results (i.e., LCC, PBP, and NIA) for unit coolers 
presented in section II.C of this document account for the updates 
discussed in this section.
b. Unit Cooler Fan Power
    As discussed in section 5.5.4.2 of the September 2023 NOPR TSD, DOE 
used unit cooler fan powers from manufacturer product catalogs to 
construct the Unit Cooler Performance Database. In general, DOE found 
that the fan powers reported in product catalogs were constant across 
unit cooler models that only appeared to differ in the number of rows 
in their heat exchangers. Further, fan motor powers per fan were the 
same across families of unit coolers having the same general geometry 
and fan diameter, where the unit coolers differed only by overall unit 
cooler length (and number of fans) and number of tube rows in the 
evaporator. As such, DOE assumed for the NOPR analysis that unit cooler 
fan power would not change when additional heat exchanger rows were 
added.
    Lennox stated that adding additional rows would have diminishing 
performance returns for several reasons including that higher fan power 
is needed to maintain airflow when additional coil depth is added due 
to the additional pressure drop imposed by the added tube rows. 
(Lennox, No. 70 at p. 4)
    Increasing heat exchanger size by adding a row could increase the 
internal static pressure (``ISP'') that the unit cooler fan would need 
to overcome and would therefore require more fan power to maintain the 
same airflow at a higher

[[Page 18565]]

ISP. DOE notes that when unit cooler airflow is reported in product 
catalogs for models that only appear to differ in number of heat 
exchanger rows, the airflow generally decreases when an additional heat 
exchanger row is added, but (as previously noted) the fan power listed 
stays constant. To quantify the potential increase in fan power, DOE 
estimated the increase in ISP associated with adding additional heat 
exchanger rows using CoilDesigner.\18\ For the CoilDesigner model, DOE 
assumed heat exchanger and fan characteristics based on physical and 
catalog teardowns of unit coolers and unit cooler airflow based on 
manufacturer product catalogs. DOE estimated a percentage fan power 
increase using representative fan performance curves, the reported air 
flow, and unit cooler system pressure drop before and after adding the 
coil row, accounting for the additional ISP estimated using 
CoilDesigner. Based on this analysis, DOE has tentatively determined 
that increasing the number of heat exchanger rows from 2 to 3 or 3 to 4 
would result in roughly a 6-percent increase in unit cooler fan power, 
and increasing heat exchanger rows from 4 to 5 would result in roughly 
a 4-percent unit cooler fan power increase.
---------------------------------------------------------------------------

    \18\ CoilDesigner is a heat exchanger coil simulation tool. 
CoilDesigner Version 4.8.20221.110 was used for this analysis.
---------------------------------------------------------------------------

    Although the fan power reported in product catalogs does not appear 
to change, as the number of heat exchanger rows changes, it is likely, 
as indicated by the analysis described above, that the fan power is 
different for these models. To evaluate the potential impact of this 
variation on potential ranges of AWEF2, DOE evaluated multiple 
scenarios regarding fan power increase with the Unit Cooler Performance 
Database medium-temperature unit coolers. For medium-temperature unit 
coolers, AWEF2 depends only on the fan power and capacity, and 
questions about potential variation in the defrost energy (a factor for 
low-temperature unit coolers), would not apply. The initial 
construction of the Unit Cooler Performance Database, posted to the 
rulemaking docket, was based on using the literature fan power as 
reported (i.e., DOE did not consider any changes to fan power based on 
number of rows).\19\ DOE further evaluated two alternative approaches: 
(a) that the reported fan power applies for unit coolers with the least 
number of tube rows and therefore, the actual fan power increases above 
the levels reported in the literature with additional tube rows; and 
(b) that the reported fan power applies for the unit coolers with the 
greatest number of tube rows and therefore, the actual fan power 
decreases below the levels reported in the literature with fewer tube 
rows. For each scenario, DOE adjusted the unit cooler fan powers based 
on the ISP difference determined by DOE's Coil Designer analysis. In 
all cases, the calculated AWEF2 values include many that are lower than 
the current baseline level. However, the number of AWEF2 values that 
are lower than the current baseline level is significantly lower for 
approach (b) described previously. The highest AWEF2 values are roughly 
the same at 10.0 for the NOPR scenario (no fan power differences within 
a family of unit coolers) and scenario (b), and are lower (close to 
9.7) for scenario (a). Given that the unit coolers evaluated are all 
certified as compliant with DOE standards, and the likelihood that the 
reported motor power would apply for the highest-power (motor design) 
operating point, DOE concludes that scenario (b) is the most likely. 
DOE notes that for all three of the scenarios, the Unit Cooler 
Performance Database has AWEF2 values that are higher than the max-tech 
AWEF2 values calculated for the representative capacities. Thus, DOE 
concludes that the max-tech efficiency levels considered in the NOPR 
were not overestimated due to the potential increase in fan power as 
additional tube rows are added within the range considered. Therefore, 
DOE did not adjust the unit cooler AWEF2 values proposed in the 
September 2023 NOPR based on the potential for additional unit cooler 
rows to impose additional ISP that could require increased fan power. 
The results of the three scenarios are shown in Figure 5.1 through 
Figure 5.3 of the NODA support document that has been posted to the 
docket.
---------------------------------------------------------------------------

    \19\ The Unit Cooler Performance Database can be found at 
www.regulations.gov/document/EERE-2017-BT-STD-0009-0064.
---------------------------------------------------------------------------

c. Miscellaneous Updates to the Unit Cooler Analysis
    After the September 2023 NOPR was published, DOE identified an 
issue in the calculation of baseline net capacities for high-
temperature unit coolers in its engineering analysis. DOE corrected 
this issue for this NODA and as a result baseline AWEF2 values are 
slightly less than the AWEF2 values shown in the NOPR. Additionally, 
since the AWEF2 values at efficiency levels above baseline are 
dependent on the baseline AWEF2 values for the high-temperature unit 
cooler analysis, the AWEF2 values at higher efficiency levels are less 
than those AWEF2 values shown in the NOPR. On average, the calculated 
efficiencies of all high-temperature unit cooler efficiency levels have 
decreased by 2-percent from the NOPR values.
    In addition, DOE found an issue in the calculation of the max-tech 
MPC of the UC.L.009 representative unit, which resulted in a higher 
MPC. For this NODA analysis, DOE addressed this calculation issue, 
which results in an MPC that is 4-percent lower than the MPC presented 
in the September 2023 NOPR. When accounting for this change and the MPC 
change associated with the cabinet size increase cost adder discussed 
in section II.A.3.a, the MPC determined for this NODA is 2-percent less 
than the MPC presented in the NOPR for this representative unit.
    See section 3 of the NODA support document that has been posted to 
the docket for the updated cost-efficiency curves that includes these 
corrections. The analytical results (i.e., LCC, PBP, and NIA) presented 
in section II.C of this document account for these corrections.

B. Trial Standard Levels

    DOE analyzed the benefits and burdens of three trial standard 
levels (``TSLs'') for the considered walk-in doors, panels, and 
refrigeration systems in the September 2023 NOPR. 88 FR 60746, 60785-
60786.
    DOE notes that the TSLs presented in this NODA are tentative and 
for evaluating the analytical changes considered in the context of this 
NODA and DOE may revise the number of, or structure of, these TSLs in 
response to comments in future analysis. DOE further notes that the 
TSLs presented in this NODA are within or close to the range of values 
presented in the September 2023 NOPR.
1. Refrigeration Systems
    For this NODA, DOE is presenting three TSLs to demonstrate the 
changes discussed in sections II.A.2 and II.A.3 of this document that 
pertain to refrigeration systems. The efficiency levels that correspond 
to these TSLs for these equipment classes are shown in Table II.5 
through Table II.7.
    TSL 3 in this NODA includes the efficiency levels that use the 
combination of design options for each representative unit at the 
maximum technologically feasible (``max-tech'') level. For this NODA, 
DOE notes a correction here where in the NOPR, the design option 
representing max-tech for the DC.M.O.054 representative unit was mapped 
to EL 7--when in fact it should have been EL 8. With the added 
efficiency level in this NODA, the max-tech efficiency level for the 
DC.M.O.054 representative unit is now EL 9 as shown in Table II.5. TSL 
1 represents

[[Page 18566]]

the efficiency levels in this NODA that yield AWEF2 values closest to 
those AWEF2 values that align with TSL 2 in the September 2023 NOPR, 
which is the TSL that DOE proposed to adopt. TSL 2 in this NODA is an 
intermediate TSL that is higher than TSL 1 but below the max-tech 
level.

           Table II.5--Refrigeration Systems Efficiency Level by Representative Unit Mapping for TSL 3
----------------------------------------------------------------------------------------------------------------
                                                                    Capacity (kBtu/hr)
                                         -----------------------------------------------------------------------
                                             2       3       6       7       9      25      54      75      124
----------------------------------------------------------------------------------------------------------------
                                           Dedicated Condensing Units
----------------------------------------------------------------------------------------------------------------
Low Temperature, Indoor (DC.L.I)........  ......       2  ......  ......       1       3       2  ......  ......
Low Temperature, Outdoor (DC.L.O).......  ......       3  ......  ......       5       8       5       4  ......
Medium Temperature, Indoor (DC.M.I).....  ......  ......  ......  ......       1       3       4       3  ......
Medium Temperature, Outdoor (DC.M.O)....  ......  ......  ......  ......       8       8       9       8       9
----------------------------------------------------------------------------------------------------------------
                                        Single-packaged Dedicated Systems
----------------------------------------------------------------------------------------------------------------
High Temperature, Ducted, Indoor               2  ......  ......       2  ......  ......  ......  ......  ......
 (SP.H.ID)..............................
High Temperature, Ducted, Outdoor              6  ......  ......       6  ......  ......  ......  ......  ......
 (SP.H.OD)..............................
High Temperature, Indoor (SP.H.I).......       2  ......  ......       2  ......  ......  ......  ......  ......
High Temperature, Outdoor (SP.H.O)......       6  ......  ......       6  ......  ......  ......  ......  ......
Low Temperature, Indoor (SP.L.I)........       7  ......       2  ......  ......  ......  ......  ......  ......
Low Temperature, Outdoor (SP.L.O).......       4  ......       4  ......  ......  ......  ......  ......  ......
Medium Temperature, Indoor (SP.M.I).....       5  ......  ......  ......       3  ......  ......  ......  ......
Medium Temperature, Outdoor (SP.M.O)....       9  ......  ......  ......       5  ......  ......  ......  ......
----------------------------------------------------------------------------------------------------------------
                                                  Unit Coolers
----------------------------------------------------------------------------------------------------------------
High Temperature (UC.H).................  ......  ......  ......  ......       1       1  ......  ......  ......
High Temperature, Ducted (UC.H.ID)......  ......  ......  ......  ......       1       1  ......  ......  ......
Low Temperature (UC.L)..................  ......       2  ......  ......       2       2       2       2  ......
Medium Temperature (UC.M)...............  ......       2  ......  ......       2       2       2       2  ......
----------------------------------------------------------------------------------------------------------------


           Table II.6--Refrigeration Systems Efficiency Level by Representative Unit Mapping for TSL 2
----------------------------------------------------------------------------------------------------------------
                                                                    Capacity (kBtu/hr)
                                         -----------------------------------------------------------------------
                                             2       3       6       7       9      25      54      75      124
----------------------------------------------------------------------------------------------------------------
                                           Dedicated Condensing Units
----------------------------------------------------------------------------------------------------------------
Low Temperature, Indoor (DC.L.I)........  ......       1  ......  ......       0       2       1  ......  ......
Low Temperature, Outdoor (DC.L.O).......  ......       2  ......  ......       4       7       4       3  ......
Medium Temperature, Indoor (DC.M.I).....  ......  ......  ......  ......       0       2       3       2  ......
Medium Temperature, Outdoor (DC.M.O)....  ......  ......  ......  ......       3       3       4       3       4
----------------------------------------------------------------------------------------------------------------
                                        Single-packaged Dedicated Systems
----------------------------------------------------------------------------------------------------------------
High Temperature, Ducted, Indoor               2  ......  ......       2  ......  ......  ......  ......  ......
 (SP.H.ID)..............................
High Temperature, Ducted, Outdoor              6  ......  ......       6  ......  ......  ......  ......  ......
 (SP.H.OD)..............................
High Temperature, Indoor (SP.H.I).......       2  ......  ......       2  ......  ......  ......  ......  ......
High Temperature, Outdoor (SP.H.O)......       5  ......  ......       5  ......  ......  ......  ......  ......
Low Temperature, Indoor (SP.L.I)........       4  ......       1  ......  ......  ......  ......  ......  ......
Low Temperature, Outdoor (SP.L.O).......       2  ......       2  ......  ......  ......  ......  ......  ......
Medium Temperature, Indoor (SP.M.I).....       3  ......  ......  ......       1  ......  ......  ......  ......
Medium Temperature, Outdoor (SP.M.O)....       8  ......  ......  ......       3  ......  ......  ......  ......
----------------------------------------------------------------------------------------------------------------
                                                  Unit Coolers
----------------------------------------------------------------------------------------------------------------
High Temperature (UC.H).................  ......  ......  ......  ......       0       0  ......  ......  ......
High Temperature, Ducted (UC.H.ID)......  ......  ......  ......  ......       1       1  ......  ......  ......
Low Temperature (UC.L)..................  ......       2  ......  ......       2       2       2       2  ......
Medium Temperature (UC.M)...............  ......       2  ......  ......       2       2       2       2  ......
----------------------------------------------------------------------------------------------------------------


           Table II.7--Refrigeration Systems Efficiency Level by Representative Unit Mapping for TSL 1
----------------------------------------------------------------------------------------------------------------
                                                                    Capacity (kBtu/hr)
                                         -----------------------------------------------------------------------
                                             2       3       6       7       9      25      54      75      124
----------------------------------------------------------------------------------------------------------------
                                           Dedicated Condensing Units
----------------------------------------------------------------------------------------------------------------
Low Temperature, Indoor (DC.L.I)........  ......       1  ......  ......       0       2       1  ......  ......
Low Temperature, Outdoor (DC.L.O).......  ......       2  ......  ......       4       7       4       2  ......
Medium Temperature, Indoor (DC.M.I).....  ......  ......  ......  ......       0       2       2       2  ......
Medium Temperature, Outdoor (DC.M.O)....  ......  ......  ......  ......       2       2       2       2       2
----------------------------------------------------------------------------------------------------------------
                                        Single-packaged Dedicated Systems
----------------------------------------------------------------------------------------------------------------
High Temperature, Ducted, Indoor               2  ......  ......       2  ......  ......  ......  ......  ......
 (SP.H.ID)..............................
High Temperature, Ducted, Outdoor              5  ......  ......       6  ......  ......  ......  ......  ......
 (SP.H.OD)..............................
High Temperature, Indoor (SP.H.I).......       1  ......  ......       2  ......  ......  ......  ......  ......

[[Page 18567]]

 
High Temperature, Outdoor (SP.H.O)......       5  ......  ......       5  ......  ......  ......  ......  ......
Low Temperature, Indoor (SP.L.I)........       4  ......       1  ......  ......  ......  ......  ......  ......
Low Temperature, Outdoor (SP.L.O).......       0  ......       1  ......  ......  ......  ......  ......  ......
Medium Temperature, Indoor (SP.M.I).....       3  ......  ......  ......       1  ......  ......  ......  ......
Medium Temperature, Outdoor (SP.M.O)....       8  ......  ......  ......       3  ......  ......  ......  ......
----------------------------------------------------------------------------------------------------------------
                                                  Unit Coolers
----------------------------------------------------------------------------------------------------------------
High Temperature (UC.H).................  ......  ......  ......  ......       0       0  ......  ......  ......
High Temperature, Ducted (UC.H.ID)......  ......  ......  ......  ......       1       1  ......  ......  ......
Low Temperature (UC.L)..................  ......       2  ......  ......       2       2       2       2  ......
Medium Temperature (UC.M)...............  ......       2  ......  ......       2       2       2       2  ......
----------------------------------------------------------------------------------------------------------------

2. Non-Display Doors
    For this NODA, DOE is presenting three TSLs to demonstrate the 
changes discussed in section II.A.1 of this document that pertain to 
non-display doors. The efficiency levels that correspond to these TSLs 
for these equipment classes are shown table II.8.
    TSL 3 in this NODA includes the efficiency levels that use the 
combination of design options for each representative unit at the max-
tech level. TSL 1 and TSL 2 are intermediate TSLs between baseline and 
TSL 3. The efficiency levels for each TSL are based on the updated 
engineering analysis for non-display doors, as discussed in section 
II.A.1 of this document and as shown in the NODA support document.

                          Table II.8--Non-Display Doors Efficiency Level to TSL Mapping
----------------------------------------------------------------------------------------------------------------
                                                                               Trial standard level
                         Equipment class                         -----------------------------------------------
                                                                         1               2               3
----------------------------------------------------------------------------------------------------------------
                                            Non-display Doors, Manual
----------------------------------------------------------------------------------------------------------------
Low Temperature (NM.L)..........................................               1               3               5
Medium Temperature (NM.M).......................................               1               3               6
----------------------------------------------------------------------------------------------------------------
                                          Non-display Doors, Motorized
----------------------------------------------------------------------------------------------------------------
Low Temperature (NO.L)..........................................               1               3               5
Medium Temperature (NO.M).......................................               1               3               6
----------------------------------------------------------------------------------------------------------------

C. Analytical Results

    To quantify the impacts to consumers and the Nation from the 
additional analysis of the technologies described in section II.A of 
this document, DOE ran its life-cycle cost (``LCC'') and payback period 
(``PBP'') analysis and national impacts analysis (``NIA'') with the 
same inputs as it used in the September 2023 NOPR, with the exception 
of the changes described in sections II.A and II.B of this document. 
DOE also considered the potential impacts of the updated analysis 
discussed in this NODA on the manufacturer impact analysis (``MIA''). 
As discussed in chapter 12 of the September 2023 NOPR TSD, DOE relies 
on several sources, including the engineering analysis and the 
shipments analysis, to obtain inputs to quantify the potential impacts 
of amended energy conservation standards on the walk-in cooler and 
freezer industry. Changes to MSPs and shipments would affect industry 
revenue, and, therefore, the MIA results. However, considered in 
isolation, DOE does not expect that the changes to the engineering 
analysis or shipments distribution detailed in this NODA would 
substantively alter the industry financial results (represented by 
change in industry net present value) presented in the September 2023 
NOPR. DOE will assess and incorporate the most up-to-date data in any 
subsequent MIA conducted for this rulemaking.
1. Life-Cycle Cost and Payback Period Analysis
    DOE analyzed the economic impacts on walk-in coolers and freezers 
consumers by looking at the effects that potential amended standards at 
each TSL would have on the LCC and PBP. The detailed description of how 
DOE calculates its LCC impacts can be found in chapter 8 and associated 
appendices of the September 2023 NOPR TSD.
    In general, higher-efficiency equipment affect consumers in two 
ways: (1) purchase price increases and (2) annual operating costs 
decrease. Inputs used for calculating the LCC and PBP include total 
installed costs (i.e., product price plus installation costs), and 
operating costs (i.e., annual energy use, energy prices, energy price 
trends, repair costs, and maintenance costs). The LCC calculation also 
uses product lifetime and a discount rate. For this NODA, DOE 
maintained the same methods and modeling assumptions discussed in 
chapter 8 of the September 2023 NOPR TSD with the exception of the 
revised engineering analysis discussed in section II.A of this document 
and TSL composition discussed in section II.B of this document.
a. Application of the Low-GWP Refrigerant Transition to Specific 
Regions
    As discussed in section II.A.2.c of this document, the states of 
California and Washington require the use of sub-150-GWP refrigerants. 
In the September 2023 NOPR, DOE conducted its LCC analysis at the 
geographic level of Census regions, where the region containing the 
states of California and Washington is the Western Region

[[Page 18568]]

(Region 4).\20\ To approximate any additional costs associated with 
moving to low-GWP refrigerants to consumers in California and 
Washington DOE applied the cost of the additional design options 
determined in section II.A.2.c of this document to the fraction of 
consumers in Western Census Region based on population.\21\ Theses 
weights and design option cost are shown in table II.9.
---------------------------------------------------------------------------

    \20\ See: https://www2.census.gov/geo/pdfs/maps-data/maps/reference/us_regdiv.pdf.
    \21\ See: https://www.census.gov/data/tables/time-series/demo/popest/2020s-state-total.html.

                                   Table II.9--Low-GWP Refrigerant Cost Adders
----------------------------------------------------------------------------------------------------------------
                                                     Capacity                       Cost adder
                       EC                            (kBtu/hr)     Census region        ($)           Weight
----------------------------------------------------------------------------------------------------------------
DC.M.I..........................................               3               4               0            0.59
                                                               3               4               0            0.41
                                                               9               4               0            0.59
                                                               9               4               0            0.41
                                                              25               4          381.20            0.59
                                                              25               4               0            0.41
                                                              54               4               0            0.59
                                                              54               4               0            0.41
                                                              75               4               0            0.59
                                                              75               4               0            0.41
DC.M.O..........................................               3               4               0            0.59
                                                               3               4               0            0.41
                                                               9               4               0            0.59
                                                               9               4               0            0.41
                                                              25               4           95.94            0.59
                                                              25               4               0            0.41
                                                              54               4               0            0.59
                                                              54               4               0            0.41
                                                              75               4               0            0.59
                                                              75               4               0            0.41
                                                             124               4               0            0.59
                                                             124               4               0            0.41
----------------------------------------------------------------------------------------------------------------

    DOE seeks comment on its approach to applying the transition to 
low-GWP refrigerant to specific regions.
b. Results for Refrigeration Systems
    Table II.10 through table II.14 show the LCC and PBP results for 
the TSLs for each category of refrigeration system equipment impacted 
in this NODA. In the first of each pair of tables by equipment category 
(dedicated refrigeration systems, single-packaged dedicated 
refrigeration systems, etc.), the simple payback is measured relative 
to the baseline equipment. In the second table, impacts are measured 
relative to the efficiency distribution in the no-new-standards case in 
the compliance year. The savings refer only to consumers who are 
affected by a standard at a given TSL. Those who already purchase 
equipment with efficiency at or above a given TSL are not affected. 
Consumers for whom the LCC increases at a given TSL experience a net 
cost.

                                         Table II.10--Average LCC and PBP Results for Dedicated Condensing Units
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                        Average costs (2023$)
                                           ------------------------------------------------------------------------------ Simple payback      Average
                    TSL                                                    First year's      Lifetime                      period (yrs)   lifetime (yrs)
                                                   Installed cost         operation cost  operating cost        LCC
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                              Dedicated Condensing Units, Low Temperature, Indoor (DC.L.I)
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.........................................  7,643.......................           2,486          22,151          29,793             0.0            10.6
1.........................................  7,771.......................           2,435          21,844          29,615             3.2            10.6
2.........................................  7,771.......................           2,435          21,844          29,615             3.2            10.6
3.........................................  10,891......................           2,331          22,956          33,847             inf            10.6
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                              Dedicated Condensing Units, Low Temperature, Outdoor (DC.L.O)
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.........................................  26,579......................           3,790          39,853          66,432             0.0            10.5
1.........................................  26,799......................           3,731          39,540          66,339             5.3            10.5
2.........................................  26,885......................           3,724          39,546          66,430             7.5            10.5
3.........................................  38,360......................           3,321          43,510          81,870             inf            10.5
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                             Dedicated Condensing Units, Medium Temperature, Indoor (DC.M.I)
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.........................................  3,783.......................           1,164          10,379          14,162             0.0            10.5
1.........................................  3,882.......................           1,123          10,126          14,008             3.0            10.5
2.........................................  3,921.......................           1,111          10,058          13,979             3.3            10.5

[[Page 18569]]

 
3.........................................  5,107.......................           1,037          10,214          15,320            64.4            10.5
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Dedicated Condensing Units, Medium Temperature, Outdoor (DC.M.O)
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.........................................  5,757.......................           1,661          15,136          20,892             0.0            10.6
1.........................................  5,761.......................           1,648          15,041          20,802             0.4            10.6
2.........................................  5,884.......................           1,607          14,799          20,683             2.9            10.6
3.........................................  8,470.......................           1,297          14,004          22,474            18.7            10.6
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: The results for each TSL are calculated assuming that all consumers use equipment at that efficiency level. The PBP is measured relative to the
  baseline equipment.


      Table II.11--LCC Savings Relative to the Base Case Efficiency
               Distribution for Dedicated Condensing Units
------------------------------------------------------------------------
                                                       Average savings--
               TSL                 % Consumers with   impacted consumers
                                       net cost             (2023$)
------------------------------------------------------------------------
      Dedicated Condensing Units, Low Temperature, Indoor (DC.L.I)
------------------------------------------------------------------------
1...............................                   7                 276
2...............................                   7                 276
3...............................                 100              -4,054
------------------------------------------------------------------------
      Dedicated Condensing Units, Low Temperature, Outdoor (DC.L.O)
------------------------------------------------------------------------
1...............................                  28                  93
2...............................                  47                   2
3...............................                 100             -15,438
------------------------------------------------------------------------
     Dedicated Condensing Units, Medium Temperature, Indoor (DC.M.I)
------------------------------------------------------------------------
1...............................                   1                 594
2...............................                   2                 709
3...............................                  97              -1,159
------------------------------------------------------------------------
    Dedicated Condensing Units, Medium Temperature, Outdoor (DC.M.O)
------------------------------------------------------------------------
1...............................                   0                  90
2...............................                   3                 209
3...............................                  95              -1,582
------------------------------------------------------------------------
Note: The savings represent the average LCC for affected consumers.


                                     Table II.12--Average LCC and PBP Results for Single-Packaged Dedicated Systems
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                               Average costs (2023$)
                                                         ----------------------------------------------------------------     Simple          Average
                           TSL                                             First year's      Lifetime                         payback        lifetime
                                                             Installed       operation       operating          LCC        period  (yrs)       (yrs)
                                                               cost            cost            cost
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                      Single-packaged Dedicated Systems, High Temperature, Ducted, Indoor (SP.H.ID)
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.......................................................           2,051             436           3,977           6,027             0.0            10.5
1.......................................................           2,145             370           3,586           5,731             1.7            10.5
2.......................................................           2,145             370           3,586           5,731             1.7            10.5
3.......................................................           2,145             370           3,586           5,731             1.7            10.5
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                     Single-packaged Dedicated Systems, High Temperature, Ducted, Outdoor (SP.H.OD)
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.......................................................           2,820             590           5,401           8,221             0.0            10.5
1.......................................................           3,119             476           4,811           7,930             3.5            10.5
2.......................................................           3,146             474           4,819           7,965             3.8            10.5
3.......................................................           3,146             474           4,819           7,965             3.8            10.5
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                          Single-packaged Dedicated Systems, High Temperature, Indoor (SP.H.I)
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.......................................................           1,978             255           2,709           4,688             0.0            10.5
1.......................................................           2,006             230           2,557           4,563             1.3            10.5
2.......................................................           2,035             226           2,550           4,585             2.5            10.5

[[Page 18570]]

 
3.......................................................           2,035             226           2,550           4,585             2.5            10.5
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                          Single-packaged Dedicated Systems, High Temperature, Outdoor (SP.H.O)
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.......................................................           2,857             357           3,829           6,686             0.0            10.5
1.......................................................           2,948             319           3,629           6,577             3.1            10.5
2.......................................................           2,948             319           3,629           6,577             3.1            10.5
3.......................................................           1,764              62           2,033           3,797             inf            10.5
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                           Single-packaged Dedicated Systems, Low Temperature, Indoor (SP.L.I)
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.......................................................           3,755             732           6,963          10,718             0.0            10.5
1.......................................................           3,947             665           6,621          10,568             3.9            10.5
2.......................................................           3,947             665           6,621          10,568             3.9            10.5
3.......................................................           3,947             665           6,621          10,568             3.9            10.5
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                          Single-packaged Dedicated Systems, Low Temperature, Outdoor (SP.L.O)
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.......................................................           4,951             967           9,202          14,153             0.0            10.6
1.......................................................           4,952             955           9,121          14,074             0.2            10.6
2.......................................................           4,974             951           9,095          14,068             1.5            10.6
3.......................................................           6,129             920           9,641          15,771             inf            10.6
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                         Single-packaged Dedicated Systems, Medium Temperature, Indoor (SP.M.I)
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.......................................................           4,002             713           6,958          10,959             0.0            10.5
1.......................................................           4,177             674           6,800          10,977             7.8            10.5
2.......................................................           4,177             674           6,800          10,977             7.8            10.5
3.......................................................           5,042             666           7,307          12,349             inf            10.5
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                         Single-packaged Dedicated Systems, Medium Temperature, Outdoor (SP.M.O)
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.......................................................           4,795             667           7,023          11,818             0.0            10.5
1.......................................................           4,857             636           6,846          11,703             2.5            10.5
2.......................................................           4,857             636           6,846          11,703             2.5            10.5
3.......................................................           5,806             632           7,436          13,242             inf            10.5
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: The results for each TSL are calculated assuming that all consumers use equipment at that efficiency level. The PBP is measured relative to the
  baseline equipment.


      Table II.13--LCC Savings Relative to the Base Case Efficiency
           Distribution for Single-Packaged Dedicated Systems
------------------------------------------------------------------------
                                                       Average savings--
               TSL                 % Consumers with        impacted
                                       net cost       consumers  (2023$)
------------------------------------------------------------------------
   Single-packaged Dedicated Systems, High Temperature, Ducted, Indoor
                                (SP.H.ID)
------------------------------------------------------------------------
1...............................                   0                 296
2...............................                   0                 296
3...............................                   0                 296
------------------------------------------------------------------------
  Single-packaged Dedicated Systems, High Temperature, Ducted, Outdoor
                                (SP.H.OD)
------------------------------------------------------------------------
1...............................                   5                 291
2...............................                  16                 256
3...............................                  16                 256
------------------------------------------------------------------------
  Single-packaged Dedicated Systems, High Temperature, Indoor (SP.H.I)
------------------------------------------------------------------------
1...............................                   2                 124
2...............................                   3                 103
3...............................                   3                 103
------------------------------------------------------------------------
  Single-packaged Dedicated Systems, High Temperature, Outdoor (SP.H.O)
------------------------------------------------------------------------
1...............................                   3                 108
2...............................                   3                 108
3...............................                  21                 -55
------------------------------------------------------------------------
   Single-packaged Dedicated Systems, Low Temperature, Indoor (SP.L.I)
------------------------------------------------------------------------
1...............................                   8                 150

[[Page 18571]]

 
2...............................                   8                 150
3...............................                   8                 150
------------------------------------------------------------------------
  Single-packaged Dedicated Systems, Low Temperature, Outdoor (SP.L.O)
------------------------------------------------------------------------
1...............................                   0                 105
2...............................                  20                  85
3...............................                 100              -1,618
------------------------------------------------------------------------
 Single-packaged Dedicated Systems, Medium Temperature, Indoor (SP.M.I)
------------------------------------------------------------------------
1...............................                  27                 -17
2...............................                  27                 -17
3...............................                 100              -1,390
------------------------------------------------------------------------
 Single-packaged Dedicated Systems, Medium Temperature, Outdoor (SP.M.O)
------------------------------------------------------------------------
1...............................                   6                 114
2...............................                   6                 114
3...............................                 100              -1,425
------------------------------------------------------------------------
Note: The savings represent the average LCC for affected consumers.


                                                Table II.14--Average LCC and PBP Results for Unit Coolers
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                               Average costs (2023$)
                                                         ----------------------------------------------------------------     Simple          Average
                           TSL                                             First year's      Lifetime                         payback        lifetime
                                                          Installed cost     operation       operating          LCC        period  (yrs)       (yrs)
                                                                               cost            cost
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                          Unit Coolers, High Temperature (UC.H)
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.......................................................           3,083             479           4,595           7,678             0.0            10.5
1.......................................................           3,083             479           4,595           7,678             0.0            10.5
2.......................................................           3,083             479           4,595           7,678             0.0            10.5
3.......................................................           3,223             474           4,642           7,865             inf            10.5
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                    Unit Coolers, High Temperature, Ducted (UC.H.ID)
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.......................................................           3,161             681           6,111           9,271             0.0            10.5
1.......................................................           3,212             642           5,859           9,071             1.5            10.5
2.......................................................           3,212             642           5,859           9,071             1.5            10.5
3.......................................................           3,212             642           5,859           9,071             1.5            10.5
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                          Unit Coolers, Low Temperature (UC.L)
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.......................................................           2,658           4,413          34,322          36,980             0.0            10.5
1.......................................................           2,918           4,186          32,772          35,690             1.3            10.5
2.......................................................           2,918           4,186          32,772          35,690             1.3            10.5
3.......................................................           2,918           4,186          32,772          35,690             1.3            10.5
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Unit Coolers, Medium Temperature (UC.M)
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.......................................................           2,468           1,675          13,649          16,118             0.0            10.6
1.......................................................           2,569           1,631          13,373          15,942             2.7            10.6
2.......................................................           2,569           1,631          13,373          15,942             2.7            10.6
3.......................................................           2,569           1,631          13,373          15,942             2.7            10.6
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: The results for each TSL are calculated assuming that all consumers use equipment at that efficiency level. The PBP is measured relative to the
  baseline equipment.


      Table II.15--LCC Savings Relative to the Base Case Efficiency
                      Distribution for Unit Coolers
------------------------------------------------------------------------
                                                       Average savings--
               TSL                 % Consumers with   impacted consumers
                                       net cost             (2023$)
------------------------------------------------------------------------
                  Unit Coolers, High Temperature (UC.H)
------------------------------------------------------------------------
1...............................                 n/a                 n/a
2...............................                 n/a                 n/a

[[Page 18572]]

 
3...............................                 100                -187
------------------------------------------------------------------------
            Unit Coolers, High Temperature, Ducted (UC.H.ID)
------------------------------------------------------------------------
1...............................                   0                 201
2...............................                   0                 201
3...............................                   0                 201
------------------------------------------------------------------------
                  Unit Coolers, Low Temperature (UC.L)
------------------------------------------------------------------------
1...............................                  10               1,290
2...............................                  10               1,290
3...............................                  10               1,290
------------------------------------------------------------------------
                 Unit Coolers, Medium Temperature (UC.M)
------------------------------------------------------------------------
1...............................                  23                 176
2...............................                  23                 176
3...............................                  23                 176
------------------------------------------------------------------------
Note: The savings represent the average LCC for affected consumers.

c. Results for Non-Display Doors
    Table II.16 through table II.19 show the LCC and PBP results for 
the TSLs for each non-display doors equipment class impacted in this 
NODA. In the first of each pair of tables by equipment class (manual 
non-display doors, motorized non-display doors), the simple payback is 
measured relative to the baseline equipment. In the second table, 
impacts are measured relative to the efficiency distribution in the no-
new-standards case in the compliance year. The savings refer only to 
consumers who are affected by a standard at a given TSL. Those who 
already purchase equipment with efficiency at or above a given TSL are 
not affected. Consumers for whom the LCC increases at a given TSL 
experience a net cost.
    As discussed in the September 2023 NOPR, to estimate the impacts of 
improved efficiency on walk-in envelope components (e.g., panels, 
doors), DOE must first establish the efficiencies and energy use of the 
connected refrigeration equipment. 88 FR 60746, 60786. For the purposes 
of this NODA, DOE has presented the results for non-display doors based 
on both the baseline and max-tech refrigeration system to show the 
range of potential impacts associated with each analyzed TSL.

                                          Table II.16--Average LCC and PBP Results for Manual Non-Display Doors
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                               Average costs (2023$)
                                                         ---------------------------------------------------------------- Simple payback      Average
                           TSL                                             First year's      Lifetime                      period (yrs)   lifetime (yrs)
                                                          Installed cost  operation cost  operating cost        LCC
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                    Non-display Doors, Manual, Low Temperature (NM.L)
                                                      Connected to a Baseline Refrigeration System
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.......................................................           2,663             315           2,079           4,742             0.0             8.7
1.......................................................           2,754             237           1,566           4,319             1.2             8.7
2.......................................................           2,854             161           1,068           3,922             1.3             8.7
3.......................................................           3,136             147             975           4,111             2.8             8.7
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                      Connected to a Max Tech Refrigeration System
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.......................................................           2,574             347           2,289           4,863             0.0             8.7
1.......................................................           2,705             240           1,582           4,288             1.2             8.7
2.......................................................           2,833             159           1,050           3,883             1.4             8.7
3.......................................................           3,136             145             961           4,097             2.8             8.7
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                  Non-display Doors, Manual, Medium Temperature (NM.M)
                                                      Connected to a Baseline Refrigeration System
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.......................................................           2,766              77             505           3,271             0.0             8.8
1.......................................................           2,827              51             337           3,163             2.4             8.8
2.......................................................           2,900              35             233           3,132             3.2             8.8
3.......................................................           3,229              32             211           3,439            10.4             8.8
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 18573]]

 
                                                      Connected to a Max Tech Refrigeration System
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.......................................................           2,605             108             714           3,319             0.0             8.8
1.......................................................           2,736              56             368           3,105             2.5             8.8
2.......................................................           2,850              37             246           3,095             3.4             8.8
3.......................................................           3,229              34             226           3,454             8.4             8.8
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: The results for each TSL are calculated assuming that all consumers use equipment at that efficiency level. The PBP is measured relative to the
  baseline equipment.


      Table II.17--LCC Savings Relative to the Base Case Efficiency
                Distribution for Manual Non-Display Doors
------------------------------------------------------------------------
                                                       Average savings--
               TSL                 % Consumers with   impacted consumers
                                       net cost             (2023$)
------------------------------------------------------------------------
            Non-display Doors, Manual, Low Temperature (NM.L)
              Connected to a Baseline Refrigeration System
------------------------------------------------------------------------
1...............................                   1                 607
2...............................                   1               1,049
3...............................                   5                 847
------------------------------------------------------------------------
              Connected to a Max Tech Refrigeration System
------------------------------------------------------------------------
1...............................                   1                 575
2...............................                   1                 980
3...............................                   5                 766
------------------------------------------------------------------------
          Non-display Doors, Manual, Medium Temperature (NM.M)
              Connected to a Baseline Refrigeration System
------------------------------------------------------------------------
1...............................                   3                 233
2...............................                   8                 263
3...............................                  69                 -91
------------------------------------------------------------------------
              Connected to a Max Tech Refrigeration System
------------------------------------------------------------------------
1...............................                   4                 214
2...............................                   9                 224
3...............................                  78                -135
------------------------------------------------------------------------
Note: The savings represent the average LCC for affected consumers.


                                        Table II.18--Average LCC and PBP Results for Motorized Non-Display Doors
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                               Average costs (2023$)
                                                         ---------------------------------------------------------------- Simple payback      Average
                           TSL                                             First year's      Lifetime                      period (yrs)   lifetime (yrs)
                                                          Installed cost  operation cost  operating cost        LCC
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                  Non-display Doors, Motorized, Low Temperature (NO.L)
                                                      Connected to a Baseline Refrigeration System
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.......................................................           7,120             495           3,244          10,364             0.0             8.7
1.......................................................           7,240             362           2,376           9,615             0.9             8.7
2.......................................................           7,367             253           1,663           9,029             1.0             8.7
3.......................................................           7,688             223           1,466           9,154             2.1             8.7
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                      Connected to a Max Tech Refrigeration System
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.......................................................           7,102             480           3,146          10,248             0.0             8.7
1.......................................................           7,233             341           2,237           9,470             0.9             8.7
2.......................................................           7,363             237           1,558           8,921             1.1             8.7
3.......................................................           7,688             210           1,381           9,069             2.2             8.7
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 18574]]

 
                                                 Non-display Doors, Motorized, Medium Temperature (NO.M)
                                                      Connected to a Baseline Refrigeration System
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.......................................................           7,333              91             597           7,930             0.0             8.8
1.......................................................           7,377              66             436           7,813             1.8             8.8
2.......................................................           7,435              50             331           7,767             2.5             8.8
3.......................................................           7,704              45             298           8,002             8.1             8.8
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                      Connected to a Max Tech Refrigeration System
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.......................................................           7,059             151             992           8,051             0.0             8.8
1.......................................................           7,190              81             536           7,727             1.9             8.8
2.......................................................           7,307              56             373           7,679             2.6             8.8
3.......................................................           7,704              50             333           8,037             6.4             8.8
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: The results for each TSL are calculated assuming that all consumers use equipment at that efficiency level. The PBP is measured relative to the
  baseline equipment.


      Table II.19--LCC Savings Relative to the Base Case Efficiency
                Distribution for Manual Non-Display Doors
------------------------------------------------------------------------
                                                       Average savings--
               TSL                 % Consumers with   impacted consumers
                                       net cost             (2023$)
------------------------------------------------------------------------
          Non-display Doors, Motorized, Low Temperature (NO.L)
              Connected to a Baseline Refrigeration System
------------------------------------------------------------------------
1...............................                   0                 819
2...............................                   0               1,417
3...............................                   2               1,291
------------------------------------------------------------------------
              Connected to a Max Tech Refrigeration System
------------------------------------------------------------------------
1...............................                   0                 778
2...............................                   0               1,326
3...............................                   2               1,179
------------------------------------------------------------------------
         Non-display Doors, Motorized, Medium Temperature (NO.M)
              Connected to a Baseline Refrigeration System
------------------------------------------------------------------------
1...............................                   1                 349
2...............................                   3                 424
3...............................                  42                  77
------------------------------------------------------------------------
              Connected to a Max Tech Refrigeration System
------------------------------------------------------------------------
1...............................                   1                 324
2...............................                   4                 372
3...............................                  51                  14
------------------------------------------------------------------------
Note: The savings represent the average LCC for affected consumers.

2. National Impacts Analysis
    This section presents DOE's estimates of the changes in national 
energy savings (``NES'') and the net present value (``NPV'') of 
consumer benefits that would result from each of the TSLs as potential 
amended standards for the equipment under consideration in this NODA. 
For this NODA, DOE maintained the methodologies and modeling 
assumptions that were used in the 2023 September NOPR. For brevity the 
NIA results are presented here by equipment category (i.e., 
refrigeration systems), the results for each equipment class can be 
found in section 6 of the NODA support document.
    The detailed description of how DOE calculates its national impacts 
can be found in chapter 10 and associated appendices of the September 
2023 NOPR TSD.
a. Non-Display Doors
    As discussed in the September 2023 NOPR, the energy savings from 
improved insulation or reduced heat infiltration would be realized as 
reduced load on the attached refrigeration systems; however, for the 
purpose of reporting, these energy savings are attributed to the 
individual door in question. 88 FR 60746, 60788. For this NODA, when 
determining the NES and NPV of consumer benefits of

[[Page 18575]]

each TSL DOE bounds the range of potential costs and benefits for non-
display doors when they are connected to max-tech refrigeration systems 
(the low bound), and baseline refrigeration systems (the high bound). 
These results are shown in table II.21 and table II.23.
b. Significance of Energy Savings
    To estimate the energy savings attributable to potential amended 
standards for walk-in refrigeration systems, DOE compared their energy 
consumption under the no-new-standards case to their anticipated energy 
consumption under each TSL. The savings are measured over the entire 
lifetime of equipment purchased in the 30-year period that begins in 
the year of anticipated compliance with amended standards (2027-2056). 
Table II.20 and table II.21 present DOE's projections of the NES for 
each TSL considered for walk-in refrigeration systems shown in section 
II.B. The savings were calculated using the approach described in 
chapter 10 of the September 2023 NOPR TSD.\22\
---------------------------------------------------------------------------

    \22\ See: www.regulations.gov/document/EERE-2017-BT-STD-0009-
0046.

  Table II.20--Cumulative Full-Fuel Cycle National Energy Savings for Walk-In Coolers and Freezer Refrigeration
                                     Systems (Quads); 30 Years of Shipments
                                                   [2027-2056]
----------------------------------------------------------------------------------------------------------------
                                                                               Trial standard level
                                                                 -----------------------------------------------
                                                                         1               2               3
----------------------------------------------------------------------------------------------------------------
                                                                                      (quads)
----------------------------------------------------------------------------------------------------------------
Primary energy..................................................            0.86            1.11            3.51
FFC energy......................................................            0.89            1.14            3.61
----------------------------------------------------------------------------------------------------------------


  Table II.21--Cumulative Full-Fuel Cycle National Energy Savings for Walk-In Coolers and Freezers: Non-Display
                                      Doors (Quads); 30 Years of Shipments
                                                   [2027-2056]
----------------------------------------------------------------------------------------------------------------
                                                                               Trial standard level
                                                                 -----------------------------------------------
                                                                         1               2               3
----------------------------------------------------------------------------------------------------------------
                                                                                      (quads)
----------------------------------------------------------------------------------------------------------------
Primary energy..................................................    0.27 to 0.28    0.58 to 0.61    0.65 to 0.70
FFC energy......................................................    0.28 to 0.29    0.59 to 0.63    0.67 to 0.72
----------------------------------------------------------------------------------------------------------------

c. Net Present Value of Consumer Costs and Benefits
    DOE estimated the cumulative NPV of the total costs and savings for 
consumers that would result from the TSLs considered for walk-in 
refrigeration systems. In accordance with the Office of Management and 
Budget's guidelines on regulatory analysis,\23\ DOE calculated NPV 
using both a 7-percent and a 3-percent real discount rate. Table II.22 
and table II.23 show the consumer NPV results with impacts counted over 
the lifetime of walk-in coolers and freezers refrigeration systems and 
non-display doors purchased in 2027-2056.
---------------------------------------------------------------------------

    \23\ U.S. Office of Management and Budget. Circular A-4: 
Regulatory Analysis. September 17, 2003. www.whitehouse.gov/wp-content/uploads/legacy_drupal_files/omb/circulars/A4/a-4.pdf (last 
accessed April 26, 2023).

  Table II.22--Cumulative Net Present Value of Consumer Benefits for Walk-In Coolers and Freezers Refrigeration
                                         Systems; 30 Years of Shipments
                                                   [2027-2056]
----------------------------------------------------------------------------------------------------------------
                                                                              Trial standard level
                         Discount rate                         -------------------------------------------------
                                                                       1               2                3
----------------------------------------------------------------------------------------------------------------
                                                                                 (billion 2023$)
----------------------------------------------------------------------------------------------------------------
3 percent.....................................................            1.53            1.57            -25.45
7 percent.....................................................            0.64            0.62            -13.15
----------------------------------------------------------------------------------------------------------------


[[Page 18576]]


  Table II.23--Cumulative Net Present Value of Consumer Benefits for Walk-In Coolers and Freezers: Non-Display
                                          Doors; 30 Years of Shipments
                                                   [2027-2056]
----------------------------------------------------------------------------------------------------------------
                                                                              Trial standard level
                         Discount rate                         -------------------------------------------------
                                                                       1               2                3
----------------------------------------------------------------------------------------------------------------
                                                                                 (billion 2022$)
----------------------------------------------------------------------------------------------------------------
3 percent.....................................................    0.78 to 0.83    1.57 to 1.72    -0.43 to -0.24
7 percent.....................................................    0.35 to 0.37    0.69 to 0.76    -0.43 to -0.35
----------------------------------------------------------------------------------------------------------------

D. Updated Equations for Proposed Standards

1. Energy Consumption Equations for Non-Display Doors
    In the September 2023 NOPR, DOE proposed amended energy 
conservation standards for walk-in non-display doors at TSL 2 from the 
NOPR analysis. 88 FR 60746, 60748. Table II.24 presents updated MDEC 
curves for the affected equipment classes at the same trial standard 
level proposed in the September 2023 NOPR using the updated analysis 
presented in this NODA.

 Table II.24--Changes to Energy Conservation Standards for Walk-In Non-
            Display Doors Proposed in the September 2023 NOPR
------------------------------------------------------------------------
                                    TSL 2 NOPR
        Equipment class           equations for     TSL 2 NODA equations
                                 MDEC (kWh/day) *   for MDEC (kWh/day) *
------------------------------------------------------------------------
Non-Display Door, Manual,       0.01 x And + 0.25  0.01 x And + 0.25 +
 Medium Temperature.                                0.33a + 0.25b +
                                                    0.07c + 0.24d.
Non-Display Door, Manual, Low   0.06 x And + 1.32  0.06 x And + 1.35 +
 Temperature.                                       0.40a + 1.42b +
                                                    0.09c + 0.30d +
                                                    0.85e.
Non-Display Door, Motorized,    0.01 x And + 0.39  0.01 x And + 0.39 +
 Medium Temperature.                                0.33a + 0.25b +
                                                    0.07c + 0.24d.
Non-Display Door, Motorized,    0.05 x And + 1.56  0.05 x And + 1.59 +
 Low Temperature.                                   0.40a + 1.42b +
                                                    0.09c + 0.30d +
                                                    0.85e.
------------------------------------------------------------------------
And represents the surface area of the non-display door.
a = 1 for a door with lighting and = 0 for a door without lighting.
b = 1 for a door with a heated viewport window and = 0 for a door
  without a heated viewport window.
c = 1 for a door with a digital temperature display without alarms and =
  0 for a door without a digital display without alarms.
d = 1 for a door with a digital temperature display with alarms and = 0
  for a door without a digital temperature display with alarms.
e = 1 for a door with a heated pressure relief vent and = 0 for a door
  without a heated pressure relief vent.

2. AWEF2 Equations
    In the September 2023 NOPR, DOE proposed amended energy 
conservation standards for walk-in refrigeration system equipment at 
TSL 2 from the NOPR analysis. 88 FR 60746, 60748. The equations for the 
proposed amended energy conservation standards for dedicated condensing 
units and single-packaged dedicated systems generally followed the 
trends of the TSL 2 levels determined for the analyzed representative 
capacities. For unit coolers, DOE proposed energy conservation 
standards that do not vary with capacity.
    AHRI and Hussmann commented on the proposed energy conservation 
standards for unit coolers by providing plots for medium- and low-
temperature unit coolers showing that DOE proposed AWEF2 standards 
equations that resulted in AWEF2 values above the AWEF2 values 
determined for EL 2 (i.e., the max-tech efficiency level) for certain 
representative capacities. (AHRI, No. 72 at pp. 4-5; Hussmann, No. 75 
at pp. 2-3)
    DOE notes that it proposed unit cooler standards that do not depend 
on capacity, averaging the proposed TSL 2 efficiency levels of the 
representative capacities within each unit cooler class. Thus, the 
proposed standard levels at higher representative capacities were above 
the max-tech efficiency levels determined for those capacities. DOE 
analyzed the unit cooler performance database to determine if the 
proposed standards for medium- and low-temperature were technologically 
feasible. DOE was able to identify low-temperature unit cooler models 
above the standard level proposed in the September 2023 NOPR across the 
full range of capacities analyzed. Therefore, DOE has tentatively 
concluded that the AWEF2 standard proposed in the September 2023 NOPR 
for low-temperature unit coolers is technologically feasible. DOE was 
unable to identify medium-temperature unit cooler models at efficiency 
levels at or above the standard level proposed in the September 2023 
NOPR at certain capacities. Therefore, DOE has revised the medium-
temperature unit cooler standard equation proposed in the September 
2023 NOPR such that it never exceeds the maximum technology level 
identified in the unit cooler performance database for given capacity 
ranges. Revised medium-temperature unit cooler standard equations are 
presented in section 7 of the NODA support document.
    In the September 2023 NOPR, DOE proposed an AWEF2 standard level 
for medium-temperature outdoor single-packaged dedicated systems of 
7.11 for models with capacities greater than or equal to 9 kBtu/h. 88 
FR 60746, 60853. In response to the September 2023 NOPR, the Efficiency 
Advocates commented that DOE's proposed AWEF2 standard of 7.11 
corresponds to EL 1 for 9 kBtu/h medium-temperature outdoor single-
packaged dedicated systems even though table IV.26 in the September 
2023 NOPR maps TSL 2 to EL 3 (Efficiency Advocates, No. 77 at p. 6). 
DOE acknowledges that table IV.26

[[Page 18577]]

in the September 2023 NOPR maps TSL 2 for 9 kBtu/h medium-temperature 
single-packaged outdoor dedicated systems to EL 3, which has an AWEF2 
of 7.5. 88 FR 60746, 60787. Additionally, table 5A.5.21 in appendix 5A 
in the September 2023 NOPR TSD specifies that EL 3 of the 9 kBtu/h 
medium-temperature outdoor single-packaged dedicated systems 
(SP.M.O.009) corresponds to an AWEF2 of 7.5. However, the proposed 
standard level for medium-temperature outdoor single-packaged dedicated 
systems was erroneously set based on an AWEF2 of 7.11 for the 
representative capacity of 9 kBtu/h. DOE has corrected this in table 
7.1 of the NODA Support Document.
    Section 7 of the NODA Support Document presents updated AWEF2 
calculations for refrigeration system equipment classes at the trial 
standards levels presented in this NODA.

III. Public Participation

    DOE requests comment on the updated efficiency levels, incremental 
MPCs, LCC, PBP, and NIA results for walk-in refrigeration systems 
presented in the NODA. As noted in the September 2023 NOPR, DOE may 
adopt energy efficiency levels that are either higher or lower than the 
proposed standards, or some combination of level(s) that incorporate 
the proposed standards in part.
    DOE will accept comments, data, and information regarding this NODA 
no later than the date provided in the DATES section at the beginning 
of this document. Interested parties may submit comments, data, and 
other information using any of the methods described in the ADDRESSES 
section at the beginning of this document.
    Submitting comments via www.regulations.gov. The 
www.regulations.gov web page will require you to provide your name and 
contact information. Your contact information will be viewable to DOE 
Building Technologies staff only. Your contact information will not be 
publicly viewable except for your first and last names, organization 
name (if any), and submitter representative name (if any). If your 
comment is not processed properly because of technical difficulties, 
DOE will use this information to contact you. If DOE cannot read your 
comment due to technical difficulties and cannot contact you for 
clarification, DOE may not be able to consider your comment.
    However, your contact information will be publicly viewable if you 
include it in the comment itself or in any documents attached to your 
comment. Any information that you do not want to be publicly viewable 
should not be included in your comment, nor in any document attached to 
your comment. Otherwise, persons viewing comments will see only first 
and last names, organization names, correspondence containing comments, 
and any documents submitted with the comments.
    Do not submit to www.regulations.gov information for which 
disclosure is restricted by statute, such as trade secrets and 
commercial or financial information (hereinafter referred to as 
Confidential Business Information (``CBI'')). Comments submitted 
through www.regulations.gov cannot be claimed as CBI. Comments received 
through the website will waive any CBI claims for the information 
submitted. For information on submitting CBI, see the Confidential 
Business Information section.
    DOE processes submissions made through www.regulations.gov before 
posting. Normally, comments will be posted within a few days of being 
submitted. However, if large volumes of comments are being processed 
simultaneously, your comment may not be viewable for up to several 
weeks. Please keep the comment tracking number that www.regulations.gov 
provides after you have successfully uploaded your comment.
    Submitting comments via email, hand delivery/courier, or postal 
mail. Comments and documents submitted via email, hand delivery/
courier, or postal mail also will be posted to www.regulations.gov. If 
you do not want your personal contact information to be publicly 
viewable, do not include it in your comment or any accompanying 
documents. Instead, provide your contact information in a cover letter. 
Include your first and last names, email address, telephone number, and 
optional mailing address. The cover letter will not be publicly 
viewable as long as it does not include any comments.
    Include contact information each time you submit comments, data, 
documents, and other information to DOE. If you submit via postal mail 
or hand delivery/courier, please provide all items on a CD, if 
feasible, in which case it is not necessary to submit printed copies. 
No telefacsimiles (``faxes'') will be accepted.
    Comments, data, and other information submitted to DOE 
electronically should be provided in PDF (preferred), Microsoft Word or 
Excel, WordPerfect, or text (ASCII) file format. Provide documents that 
are not secured, that are written in English, and that are free of any 
defects or viruses. Documents should not contain special characters or 
any form of encryption and, if possible, they should carry the 
electronic signature of the author.
    Campaign form letters. Please submit campaign form letters by the 
originating organization in batches of between 50 to 500 form letters 
per PDF or as one form letter with a list of supporters' names compiled 
into one or more PDFs. This reduces comment processing and posting 
time.
    Confidential Business Information. Pursuant to 10 CFR 1004.11, any 
person submitting information that he or she believes to be 
confidential and exempt by law from public disclosure should submit via 
email two well-marked copies: one copy of the document marked 
``confidential'' including all the information believed to be 
confidential, and one copy of the document marked ``non-confidential'' 
with the information believed to be confidential deleted. DOE will make 
its own determination about the confidential status of the information 
and treat it according to its determination.
    It is DOE's policy that all comments may be included in the public 
docket, without change and as received, including any personal 
information provided in the comments (except information deemed to be 
exempt from public disclosure).

IV. Approval of the Office of the Secretary

    The Secretary of Energy has approved publication of this 
notification of data availability and request for comment.

Signing Authority

    This document of the Department of Energy was signed on March 11, 
2024, by Jeffrey Marootian, Principal Deputy Assistant Secretary for 
Energy Efficiency and Renewable Energy, pursuant to delegated authority 
from the Secretary of Energy. That document with the original signature 
and date is maintained by DOE. For administrative purposes only, and in 
compliance with requirements of the Office of the Federal Register, the 
undersigned DOE Federal Register Liaison Officer has been authorized to 
sign and submit the document in electronic format for publication, as 
an official document of the Department of Energy. This administrative 
process in no way alters the legal effect of this document upon 
publication in the Federal Register.


[[Page 18578]]


    Signed in Washington, DC, on March 11, 2024.
Treena V. Garrett,
Federal Register Liaison Officer, U.S. Department of Energy.
[FR Doc. 2024-05462 Filed 3-13-24; 8:45 am]
BILLING CODE 6450-01-P