to the GWP restrictions and charge sizes can be found in the IPR
section VI.F.1.a.
    Response: After review of the comments received, EPA is finalizing,
as proposed, a 150 GWP limit for units with refrigerant charge
capacities greater than or equal to 200 lb, a 300 GWP limit for new
cold storage warehouses with refrigerant charge capacities less than
200 lb, and a 300 GWP limit for units in the high temperature side of
cascade systems, irrespective of the charge capacity. See response
above in the IPR section VI.F.1.a for more discussion about the
relationship between GWP restrictions and charge size.
    Comment: One commenter objected generally to the proposed GWP
limits for cold storage warehouses due to a lack of available
replacement technology sufficient for transition. Many commenters
expressed that EPA's proposed GWP limits may require the use of toxic
and/or flammable refrigerant options and stated that for safety
reasons, A1 refrigeration options are needed for their operations.
    Response: EPA does not agree with the commenters' assertions that
there is a lack of available alternatives. The Agency noted a number of
available alternatives earlier in the section, in the proposed rule,
and in other supporting information. EPA identified several substitutes
in place of the restricted substances for cold storage warehouses. Of
these, options with an ASHRAE classification of A1 (low toxicity,
nonflammable at standard conditions) are HCFO-1233zd(E) and R-471A.
    Comment: One commenter expressed support for the proposed 2025
transition date for commercial refrigeration, including cold storage
warehouses. Some commenters requested a date of January 1, 2026, to
allow for updated building codes, equipment readiness, testing of new
refrigerants, and SNAP listing of replacements. Many commenters stated
the compliance dates are unrealistic, and that more time was needed for
manufacturers to find a solution that can be designed, tested, sold,
and produced by these dates. One commenter stated the compliance date
of January 1, 2025, is extremely challenging for cold storage
warehouses, and a major limitation on the HFC transition was the lack
of SNAP-approved low-GWP listings for refrigeration, hindering their
ability to conduct field trials and installations. See other comments
related to the proposed compliance date in IPR section VI.F.1.a.
    Response: After review of the comments received applicable to the
proposed compliance date for cold storage warehouses, and consideration
of the (i)(4) factors under the AIM Act, EPA is finalizing a compliance
date of January 1, 2026, rather than the proposed date of January 1,
2025. EPA's assessment is that in many cases cold storage warehouses
already use refrigerants with GWPs below the limit the Agency is
finalizing today; however, the Agency's understanding, informed by the
comments, is that for certain situations, particularly where updates
for building codes are necessary, additional time is needed. EPA does
not agree with the commenters' assertions that there is a lack of
available alternatives. As described above, EPA identified several
substitutes in place of the restricted substances for cold storage
warehouses. For EPA's response to these comments and discussion on the
Agency's decision to provide an additional year to comply, see section
VI.F.1.e.
    Comment: Many commenters expressed some opposition to EPA's comment
that cold storage warehouses are typically located away from population
centers, reducing their proximity to people and thus reducing the risk
of using R-717. The commenters stated that cold storage warehouse
locations are based on market demand, land, and freight costs, but for
servicing reasons, they must be close to the population centers.
    Response: EPA acknowledges there may be certain circumstances where
it is beneficial for cold storage warehouses to be built near
population centers; however, EPA understands that there has been and
continues to be a tendency for cold storage warehouses to be located
away from densely populated areas for the reasons described above.
Other alternative refrigerants besides R-717 are available, as noted
above, which can be used if the cold storage warehouse is located in
closer proximity to people.
f. Ice Rinks
    Ice rinks use a system of refrigeration equipment to move a fluid
through pipes embedded in concrete flooring to freeze layers of water.
Ice rinks may be used by the public for recreational purposes as well
as by professionals. These systems frequently use secondary loop
refrigeration systems, in some cases consisting of a chiller along with
associated pumps that move the chilled water or glycol working fluid.
Another configuration sometimes used is a direct expansion system
wherein the refrigerant flows under the ice and directly back to a
compressor and condenser. System capacities vary based on the size of
the ice rink and the required cooling load. Typical sizes for ice rink
chillers are 50-, 100-, 150-, or 200-ton units. The ice surface is
ideally maintained between 24 to 28 [deg]F (-4.4 to -2.2 [deg]C)
depending on the application and users of the ice rink (e.g., figure
skating versus hockey).
    Ice rinks used CFC/HCFC refrigerants prior to restrictions under
the Clean Air Act, and then higher-GWP HFC blends such as R-404A and R-
507A. More recently, some ice rinks used the HFCs blends R-449A, R-
450A, and R-513A. R-717 and R-744 are also commonly used.
What restrictions on the use of HFCs is EPA establishing for ice rinks?
    EPA is prohibiting the installation of ice rink systems using HFCs
or blends containing HFCs that have a GWP of 700 or greater beginning
January 1, 2025. EPA had proposed restrictions for installation of new
ice rinks to begin January 1, 2025, but had proposed a GWP limit of 150
rather than 700.
    For its consideration of availability of substitutes under
subsection (i)(4)(B) at proposal, EPA identified the following
available substitutes: R-717 (GWP 1), R-744 (GWP 1), and HCFO-1233zd(E)
(GWP 4). R-471A (GWP 144) also meets the GWP limit and can serve as a
potential substitute. Under the restriction being finalized, R-450A
(GWP 601) and R-513A (GWP 630) are also potentially available
substitutes.
    Most new ice rinks use R-717 as a refrigerant due to its energy
efficiency, while others are being designed to use R-744 and other
lower-GWP substitutes.\126\ Although R-717 is a B2L (higher toxicity,
lower flammability) refrigerant, risks to the general public are
addressed by confining the R-717 to separate equipment (i.e., the high-
temperature side of a chiller) in locations with access limited to
trained service personnel only. In TSDs submitted with their petition,
CARB

estimated that more than 80 percent of ice rinks in California use R-
717.\127\ According to EIA's petition, a majority of National Hockey
League ice arenas also employ R-717, and the use of R-744 is becoming
an increasingly popular option for ice rinks. This information
indicates the technological achievability and commercial demand of
these substitutes.
---------------------------------------------------------------------------

    \126\ Packages--Design and Build, Toromont [bond] CIMCO
Refrigeration. Available at: https://www.cimcorefrigeration.com/packages-design-build.
    \127\ Staff Report: Initial Statement of Reasons, CARB, October
2020. Available at: https://ww2.arb.ca.gov/rulemaking/2020/hfc2020.
---------------------------------------------------------------------------

    In areas where safety or toxicity reasons prevent the use of R-717,
lower-GWP (hydrochlorofluoroolefin) HCFO or HFO chillers and lower-GWP
transcritical R-744 systems are options available for use in ice rink
systems. EPA has also recently listed HCFO-1233zd(E) as acceptable
through the SNAP program for use in new ice rinks (87 FR 3037, January
20, 2022).
    Comment: A few commenters suggested that the GWP limit for ice
rinks be increased to 700. The commenters proposed chillers and ice
rinks be categorized the same since chillers are used for ice rinks,
except for minor differences in certain components and controls. The
commenters stated that this would also prevent costs and delays that
would occur by making a specialized category for ice rinks. Increasing
the GWP limit to 700 would preserve the ability for industry to have a
wider choice of refrigerant options.
    One commenter expressed support for the GWP limit of 150 and noted
that there is no clear information available to suggest a significant
number of jurisdictions have local codes that do not allow the use of
R-717. Ammonia has been widely used for many years and other
refrigerant systems using less than 150 GWP refrigerants, including R-
744 systems, are available for use in locations that prefer to avoid
use of R-717.
    Response: After review of the comments received, EPA is finalizing
a 700 GWP limit for ice rinks. The Agency maintains that there are
available substitutes with GWPs below 150; however, EPA is applying a
700 GWP limit to use of HFCs in ice rinks because EPA agrees with
commenters that many of these refrigerant systems would utilize
chillers that are available for other applications. Most ice rink
systems are similar to chillers and frequently use secondary loop
refrigeration systems, which typically cool water, that is circulated
for cooling purposes. In most chiller applications the cool water or
working fluid is used for comfort cooling throughout a building or
other location, but for ice rinks, the cool water or working fluid is
used to freeze layers of water, which forms the ice. Although the water
or working fluid may be used for different cooling purposes in each
application, equipment used across these two subsectors is commonly
used interchangeably. We therefore agree that ice rinks and chillers
should be similarly restricted under this rule. Because ice rinks
typically maintain the ice surface between 24 and 28 [deg]F (-4.4 to -
2.2 [deg]C), it is inappropriate to adopt the temperature thresholds of
-30 [deg]C (-22 [deg]F) and -50 [deg]C (-58 [deg]F) that apply to
chillers for comfort cooling and for IPR.\128\
---------------------------------------------------------------------------

    \128\ EPA is not combining the categories of chillers and ice
rinks in this rule, nor does EPA plan to change the SNAP end-uses to
combine chillers and ice-skating rinks into a single end-use.
---------------------------------------------------------------------------

    With respect to the comments requesting a GWP limit of 700, the
Agency agrees that this limit is reasonable under the (i)(4) factors
and with the technical similarities to chillers. While the Agency
acknowledges more substitutes may be available with a GWP limit of 700,
including R-450A and R-513A, the Agency understands that the lower GWP
refrigerants like R-744 will continue to be used for both ice rinks
with chillers and direct expansion ice rinks. R-717 will typically be
used in chillers together with brine, CO2, or another
secondary fluid. As noted by a commenter, the use of R-717 in ice rinks
may be restricted in a small number of jurisdictions, and in light of
these potential limitations of R-717 due to flammability and toxicity
risks, especially the direct expansion ice rinks where the refrigerant
is sent directly to evaporators to form the ice. Therefore, EPA is
establishing a GWP limit that retains more refrigerant options for this
subsector.
    In addition to the lower-GWP refrigerants already available, EPA
continues to evaluate substitutes under the SNAP program, and has
authority to do so under subsection (i)(5) as well, on an ongoing
basis. The Agency anticipates that this continuing evaluation of
additional substitutes, including for use in ice rinks, may expand
further the availability of more options for compliance by January 1,
2025. For example, under the SNAP program, in SNAP Rule 26 EPA has
proposed to list as acceptable subject to use conditions several
additional refrigerants that would comply with today's final rule, for
use in ice rinks with a remote compressor: HFO-1234ze(E), HFO-1234yf,
R-457A, R-516A, R-455A, and R-454C (with GWPs of 1, 1, 137, 140, 146,
and 146, respectively) (88 FR 33722; May 24, 2023). These refrigerants
are classified as A2L and may face challenges for direct expansion ice
rinks in some jurisdictions. Therefore, for ice rinks EPA is finalizing
a GWP limit of 700 consistent with the GWP limit for chillers given the
technical similarities of these subsectors and given the need for
additional options for direct expansion ice rinks.
g. Automatic Commercial Ice Machines
    Automatic Commercial Ice Machines (ACIMs), either self-contained or
remote condensing, are used in commercial establishments such as
hotels, restaurants, and convenience stores to produce ice for consumer
use. For purposes of this rule, ice-making equipment used in
residential settings are covered under household refrigerators and
freezers. Self-contained units are a type of ACIM in which the ice-
making mechanism and the storage compartment, if provided, are in an
integral cabinet. They contain both evaporator and condenser, have no
external refrigerant connections, and are entirely factory-charged with
refrigerants and factory-sealed, generally containing smaller
refrigerant charges. These products are analogous to other self-
contained equipment, such as vending machines and stand-alone
refrigerated display cases.
    Remote condensing ACIMs have the condenser separated from the
portion of the machine making the ice and have refrigerant lines
running between the two. Like other types of remote condensing RACHP
systems, remote condensing ACIMs utilize a split-system design where
the evaporator (which freezes water into ice) is located indoors, while
the condensing unit (which rejects heat, usually to surrounding air
although water cooling is also a possibility) is located elsewhere,
such as outside the building. In remote-compressor systems, a type of
remote condensing ACIM, the heat is still rejected away from the ice-
making evaporator, either inside in a separate room or outdoors, but
the compressor is located outdoors via interconnected refrigerant
piping. These designs require field-assembled refrigerant piping to
connect the indoor unit with the remote condensing unit, which
significantly increases its necessary refrigerant charge in comparison
to that of a self-contained unit. Modular ice machines are designed to
sit on top of a separate unit, such as an ice bin, beverage machine, or
ice dispenser and typically produce 250 to 1,000 lb of ice per day.
Higher glide refrigerant blends have not been

typically used as substitutes for remote condensing ACIMs.
    ACIMs can also be divided between batch type machines (e.g.,
providing cubed ice) and continuous type machines (e.g., providing
flaked ice). Batch type (also called cube type) ice machines harvest
ice with alternating freezing and harvesting periods. Batch type ACIMs
can be used in a variety of applications but are generally used to
generate ice for use in beverages. Batch type ACIMs are often employed
in hotels, hospitals, and restaurants where beverages are served.
Continuous type ice makers produce ice through a continuous freeze and
harvest process and include flake and nugget ice machines. Flake ice is
used primarily in food displays, such as seafood grocery store displays
or salad bars, whereas nugget ice (also known as chewable ice) is
primarily used in beverage applications such as smoothies and blended
cocktails.
    R-404A and R-410A have been the most common HFC refrigerants
currently used in ACIMs, which replaced the use of ozone depleting
HCFCs such as R-22. R-404A is used in remote condensing ACIMs, while
both R-404A and R-410A have been commonly used in self-contained ACIMs.
What restrictions on the use of HFCs is EPA establishing for automatic
commercial ice machines?
    For new batch type self-contained ACIMs with a harvest rate \129\
less than or equal to 1,000 lb of ice per 24 hours, and new continuous
type self-contained ACIMs with a harvest rate less than or equal to
1,200 lb of ice per 24 hours, EPA is restricting the use of HFCs and
HFC blends with GWPs of 150 or greater, beginning January 1, 2026.
---------------------------------------------------------------------------

    \129\ The Department of Energy's regulations for commercial ice
machines define harvest rate as ``the amount of ice (at 32 degrees
F) in pounds produced per 24 hours.'' 10 CFR 431.132. For purposes
of this rule, the harvest rate of an ACIM shall be determined in
accordance with 10 CFR 431.134.
---------------------------------------------------------------------------

    For new batch type self-contained ACIMs with a harvest rate greater
than 1,000 lb of ice per 24 hours, and new continuous type self-
contained ACIMs with a harvest rate greater than 1,200 lb of ice per 24
hours, EPA is restricting the use of the following HFCs and HFC blends,
beginning January 1, 2027: R-402A, R-402B, R-404A, R-407A, R-407B, R-
407C, R-407F, R-408A, R-410A, R-410B, R-411A, R-411B, R-417A, R-417C,
R-420A, R-421A, R-421B, R-422A, R-422B, R-422C, R-422D, R-424A, R-426A,
R-428A, R-434A, R-437A, R-438A, R-442A, R-507A, HFC-134a, R-125/290/
134a/600a (55/1/42.5/1.5), RB-276, RS-24 (2002 formulation), RS-44
(2003 formulation), GHG-X5, G2018C, and Freeze 12.
    For new remote condensing ACIMs, EPA is restricting the use of the
following HFCs and HFC blends, beginning January 1, 2027: R-402A, R-
402B, R-404A, R-407B, R-408A, R-410B, R-417A, R-421A, R-421B, R-422A,
R-422B, R-422C, R-422D, R-424A, R-428A, R-434A, R-438A, R-507A, R-125/
290/134a/600a (55/1/42.5/1.5), RS-44 (2003 formulation), and GHG-X5.
    Currently available substitutes identified for self-contained ACIM
where the harvest rate is less than or equal to 1,000 lb of ice per day
(batch type) or 1,200 lb of ice per day (continuous type) include R-290
(GWP 3.3) and R-717 (GWP 1), and where the harvest rate is greater than
that amount R-513A (GWP 630) and R-450A (GWP 601) are available
substitutes. EPA has proposed to list many additional refrigerants as
acceptable for use in ACIMs in proposed SNAP Rule 26 (88 FR 33722, May
24, 2023). Substitute refrigerants R-455A (GWP 146) and R-454C (GWP
146) also meet the restrictions and could serve as additional potential
candidates for use in place of the HFCs and HFC blends that EPA is
restricting in self-contained units. Other proposed refrigerants such
as R-454B (GWP 465) and HFC-32 (GWP 675), which are being pursued for
other R-410A applications, and R-448A (GWP 1,386), R-449A (GWP 1,396),
R-449B (GWP 1,411), and R-454A (GWP 237), which are being pursued for
other R-404A applications, are potential candidates for self-contained
batch and continuous type ACIMs with harvest rates greater than 1,000
lb of ice per day and 1,200 lb of ice per day, respectively. Available
substitutes for remote condensing ACIMs include R-448A, R-449A, R-449B,
and HFC-134a.
    EPA's proposed restrictions included: the use of HFCs and HFC
blends with GWPs of 150 or greater for self-contained ACIMs with charge
sizes less than or equal to 500 g, beginning January 1, 2025; the use
of certain HFCs and HFC blends--R-404A, R-507, R-507A, R-428A, R-422C,
R-434A, R-421B, R-408A, R-422A, R-407B, R-402A, R-422D, R-421A, R-125/
290/134a/600a (55/1/42.5/1.5), R-422B, R-424A, R-402B, GHG-X5, R-417A,
R-438A, R-410B, R-407A, R-410A, R-442A, R-417C, R-407F, R-437A, R-407C,
RS-24 (2004 formulation), and HFC-134a--in new self-contained ACIMs
with refrigerant charge capacities exceeding 500 g, beginning January
1, 2025; and the use of certain HFCs and HFC blends--R-404A, R-507, R-
507A, R-428A, R-422C, R-434A, R-421B, R-408A, R-422A, R-407B, R-402A,
R-422D, R-421A, R-125/290/134a/600a (55/1/42.5/1.5), R-422B, R-424A, R-
402B, GHG-X5, R-417A, R-438A, and R-410B--in new remote condensing
ACIMs, beginning January 1, 2025. In finalizing these lists of HFCs and
HFC blends, we are correcting an error in the date of formulation for
RS-24 and we are adding several blends that contain HFCs that were
inadvertently left off the lists and that have higher GWPs than the
proposed prohibited HFC or HFC blend with the lowest GWP (HFC-134a for
self-contained units and R-410B for remote systems).
    EPA is finalizing three different sets of restrictions on the use
of HFCs and HFC blends in ACIMs, depending on the type of equipment.
Originally, the Agency proposed to set GWP limits for self-contained
ACIMs based on charge capacity, rather than the harvest rate for ice
production. However, in response to the comments received, the Agency
has adjusted the categorization of self-contained ACIMs to distinguish
equipment by its ice harvest (production) rate, rather than charge
capacity, to better evaluate the availability of substitutes for use in
the various applications in this subsector. Distinguishing self-
contained ACIMs by harvest rate is consistent with the Department of
Energy's energy conservation standards applicable to this subsector.
Table 4 below summarizes the final restrictions on HFCs and their
compliance dates for various ACIM applications.

                                             Table 4--HFC Restrictions for Automatic Commercial Ice Machines
--------------------------------------------------------------------------------------------------------------------------------------------------------
             ACIM type               Batch or  continuous       Harvest rate                 HFC restriction                     Compliance date
--------------------------------------------------------------------------------------------------------------------------------------------------------
Self-contained....................  Batch................  Less than or equal to  GWP less than 150...................  January 1, 2026.
                                                            1,000 pounds ice per
                                                            24 hours.
Self-contained....................  Continuous...........  Less than or equal to  GWP less than 150...................  January 1, 2026.
                                                            1,200 pounds ice per
                                                            24 hours.
Self-contained....................  Batch................  Greater than 1,000     Listed blends prohibited: R-402A, R-  January 1, 2027.
                                                            pounds ice per 24      402B, R-404A, R-407A, R-407B, R-
                                                            hours.                 407C, R-407F, R-408A, R-410A, R-
                                                                                410B, R-411A, R-411B, R-417A, R-
                                                                                417C, R-420A, R-421A, R-421B, R-
                                                                                422A, R-422B, R-422C, R-422D, R-
                                                                                424A, R-426A, R-428A, R-434A, R-
                                                                                437A, R-438A, R-442A, R-507A, HFC-
                                                                                134a, R-125/290/134a/600a (55/1/
                                                                                42.5/1.5), RB-276, RS-24 (2002
                                                                                formulation), RS-44 (2003
                                                                                formulation), GHG-X5, G2018C,
                                                                                Freeze 12.
Self-contained....................  Continuous...........  Greater than 1,200     Listed blends prohibited: R-402A, R-  January 1, 2027.
                                                            pounds ice per 24      402B, R-404A, R-407A, R-407B, R-
                                                            hours.                 407C, R-407F, R-408A, R-410A, R-
                                                                                410B, R-411A, R-411B, R-417A, R-
                                                                                417C, R-420A, R-421A, R-421B, R-
                                                                                422A, R-422B, R-422C, R-422D, R-
                                                                                424A, R-426A, R-428A, R-434A, R-
                                                                                437A, R-438A, R-442A,R-507A, HFC-
                                                                                134a, R-125/290/134a/600a (55/1/
                                                                                42.5/1.5), RB-276, RS-24 (2002
                                                                                formulation), RS-44 (2003
                                                                                formulation), GHG-X5, G2018C,
                                                                                Freeze 12.
Remote condenser..................  All..................  All..................  Listed blends prohibited: R-402A, R-  January 1, 2027.
                                                                                402B, R-404A, R-407B, R-408A, R-
                                                                                410B, R-417A, R-421A, R-421B, R-
                                                                                422A, R-422B, R-422C, R-422D, R-
                                                                                424A, R-428A, R-434A, R-438A, R-
                                                                                507A, R-125/290/134a/600a (55/1/
                                                                                42.5/1.5), RS-44 (2003
                                                                                formulation), GHG-X5.
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Comment: EPA received several comments from industry on its
proposed approach to categorizing ACIM equipment when setting
restrictions. One commenter expressed support for setting GWP limits
based on a 500 g charge capacity, as proposed. Another commenter
disagreed with the proposed approach, and instead recommended the
Agency distinguish equipment by the cooling capacity of the compressor,
recommending 3,000 BTU/hr as a possible threshold between smaller and
larger equipment. The commenter stated that this approach would better
characterize the componentry requirements of the market to inform
compressor manufacturers' product development, based on the exact
cooling capacity needs of the OEMs. This same commenter stated that for
equipment design engineers, this approach would clarify the
refrigerants available for use at the point of compressor selection,
rather than when selecting a refrigerant charge for the equipment,
given that charge is subjective and can be adjusted based on the design
preferences of the engineer. Similarly, another commenter also
disagreed with using charge capacity to distinguish equipment; instead,
they requested EPA categorize self-contained ACIMs by pounds of ice
produced per 24 hours, analogous to DOE's energy conservation
standards, recommending a 1,000 lb/day threshold when setting
restrictions. This commenter described how the refrigerant charge could
be manipulated by manufacturers to comply with the proposed
restrictions that they viewed as more lenient--simply increasing the
charge of equipment to surpass the 500 g threshold, even in cases where
a smaller charge would provide sufficient cooling capacity.
    One commenter disagreed with differentiating self-contained ACIMs
by charge size, or any other factor related to the cooling capacity or
harvest rate of the machine, and instead requested that all self-
contained ACIMs be treated the same when setting restrictions. This
commenter explained that for smaller self-contained equipment, only
hydrocarbon refrigerants were viable options under the proposed
restrictions, and that building codes may limit the refrigerant charge
below what is necessary, even if updated safety standards have expanded
the allowable charges for flammable refrigerants. By removing the
proposed charge requirement in self-contained equipment, the commenter
stated that smaller equipment would be able to continue using non-
flammable refrigerants where flammable refrigerants may not be
feasible.
    Response: After review of the comments received, EPA is finalizing
GWP limits for self-contained ACIMs based on the harvest rate of ice
production rather than the proposed basis of charge size of the
equipment. One commenter agreed with the proposed approach to setting
restrictions and EPA has considered how the availability of substitutes
for use in ACIMs is affected by various technical specifications and
concludes that setting restrictions based on ice production rates
better distinguishes equipment capable of meeting lower GWP limits from
equipment that may need additional refrigerants with higher GWPs. One
commenter recommended using the cooling capacity of the compressor as a
threshold for setting restrictions; however, EPA understands through
conversations with industry stakeholders that a categorization based on
harvest rate of ice production per day is more familiar for ACIM
manufacturers, is more likely to be considered by customers purchasing
ACIMs than cooling capacity, and mirrors DOE's approach to setting
energy conservation standards.
    Setting restrictions for self-contained ACIMs based on the cooling
capacity of

their compressors is technically similar to the categorization
finalized in this rulemaking--cooling capacity is directly related to
the equipment's harvest rate of ice production. This equipment
categorization approach will similarly clarify the cooling needs of
OEMs for compressor manufacturers and help design engineers more easily
identify which refrigerants are allowed in certain equipment, compared
to the proposed approach of categorizing based on charge size. EPA also
recognizes that equipment with near 500 g charges could face unclear
restrictions on the use of certain HFCs and HFC blends, depending on
how a design engineer chooses to design and charge the self-contained
equipment. The ability to manipulate the charge of the system could
generate a regulatory loophole for OEMs who could unnecessarily add
refrigerant charge as a way to continue to use refrigerants with GWPs
above the finalized restrictions. For these reasons, EPA is
categorizing self-contained ACIM equipment based on the harvest rate of
ice production, rather than on the refrigerant charge of the equipment.
    In selecting the harvest rate of ice production threshold for
distinguishing applicable restrictions, EPA considered the available
substitutes for various types of ACIMs and how updates to relevant
standards have affected the refrigerant options. All categories of ACIM
are covered by UL Standard 60335-2-89. The 2nd edition of this
standard, published in October 2021, recently increased the allowable
charge limits for flammable refrigerants in commercial refrigeration
equipment, including both higher- and lower flammability refrigerants
(ASHRAE flammability safety categories 2 and 3, and 2L). For self-
contained equipment using R-290, UL 60335-2-89, 2nd edition increased
the charge limit from 150 g per refrigerant circuit to either 300 g or
500 g per refrigerant circuit, depending on construction. For self-
contained ACIM, the 2nd edition set a 300 g limit for R-290 for
``packaged refrigerating units and appliances with doors and/or drawers
enclosing one or more refrigerated compartments.'' (22.110 DV.2). This
limit applies to ``unprotected'' designs where the refrigerant can leak
into the ice storage bin. For protected units, in which the refrigerant
cannot leak into the bin, 500 g of R-290 (and a similar amount for
other A3 refrigerants) is allowed in the 2nd edition. Further, UL
60335-2-89 restricts the allowable charge size of flammable refrigerant
in these appliances for ``self-contained appliances used in a public
corridor or lobby'' (22.110 DV.2). Certain flammable refrigerants
(i.e., A3s and A2s) are not allowed in any quantities in split-systems
with field-constructed refrigerant piping (22.110 DV.3). For further
discussion on the updates to UL 60335-2-89, see section VI.E.2.c.
    One commenter suggested setting this threshold at a harvest rate of
1,000 lb of ice per day and EPA agrees that such a rate is appropriate
for distinguishing batch type equipment capable of using lower-GWP
refrigerants from those that need continued use of higher-GWP options.
However, for continuous type equipment, EPA finds that a 1,200 lb of
ice per day is appropriate. These limits are consistent with comments
made to DOE by AHRI and an ACIM manufacturer.\130\ Currently, ENERGY
STAR has certified ice makers capable of producing as much as 566 lb of
ice per day using charge sizes of R-290 below the current 150 g charge
limit per SNAP Rule 21, a use condition based on the earlier industry
safety standard for commercial ice machines, UL 563, 8th edition (81 FR
86778, December 1, 2016). However, in response to the updates included
in the 2nd edition of UL 60335-2-89, on May 24, 2023, EPA proposed to
increase the allowable charge capacity of R-290 in ACIMs to 500 g in
SNAP Rule 26 (88 FR 33722, May 24, 2023). While equipment using 500 g
charges of R-290 could likely produce up to the finalized 1,000 lb of
ice per day (batch type) and 1,200 lb of ice per day (continuous type),
EPA finds that the chosen harvest rates provide reasonable limits under
which we have assessed as being capable of transitioning to R-290, or
other available substitutes with GWPs less than 150, in the finalized
compliance timeline. Such limits do not preclude manufacturers from
pursuing R-290 or other lower-GWP substitutes for equipment with
harvest rates that exceed those limits. Additionally, EPA has proposed
to list R-455A (GWP 146) and R-454C (GWP 146) for use in this
subsector, which could also work as potential candidates for these
types of ACIMs.
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    \130\ See EERE-2017-BT-STD-0022-0050 and EERE-2017-BT-STD-0022-
0047, respectively, available at www.regulations.gov.
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    Given that there will likely be a greater number of available
refrigerant options for equipment harvesting up to 1,000 lb of ice per
day (batch type) or 1,200 lb of ice per day (continuous type) by the
compliance date for this subsector in addition to R-290, which is
already used widely in ACIMs, EPA considers these harvest rates
appropriate thresholds for distinguishing self-contained equipment. The
one-year extension of the compliance date provided in this final action
will help facilitate the transition to lower-GWP refrigerants for OEMs
of smaller self-contained ACIMs harvesting less than 1,000 lb of ice
per day (batch type) or 1,200 lb of ice per day (continuous type).
    EPA considers the available substitutes for higher-GWP HFCs and HFC
blends to differ for smaller and larger ACIMs. Neat (i.e., zero glide)
refrigerants, such as R-290, are widely used in smaller, self-contained
ACIMs, where smaller charge sizes of refrigerant are capable of
providing the required cooling capacity at lower harvest rates. In
larger equipment, higher rates of ice production mandate larger charge
sizes, compounding flammability concerns with A3 refrigerants.
Equipment harvesting ice at higher rates may still need access to non-
flammable options, in addition to other, lower-flammability options,
which may be limited in their technological achievability because of
various factors such as glide. Although building codes limit the charge
of flammable refrigerants at points of public egress, and are underway
to being updated to incorporate recent additions of safety standards,
in such cases, smaller charges of A3 refrigerants (e.g., less than
approximately 114 g of R-290) are still allowable, in addition to
lower-flammability refrigerants, such as the SNAP proposed A2L
refrigerants R-454C and R-455A. Extending the compliance deadline from
January 1, 2025, to January 1, 2026, will provide additional time for
building codes to be updated; for research, development, and testing of
new self-contained ACIM models; and for additional substitutes to enter
the market for this subsector. Therefore, smaller equipment capable of
using lower-GWP refrigerants will have a sufficient number of
refrigerant options to select from, highlighting the usefulness of
distinguishing self-contained ACIMs by their rate of ice production
when setting restrictions. For these reasons, EPA disagrees with the
commenter that suggested removing the distinction, either by charge
size or rate of ice production, of smaller and larger self-contained
ACIMs.
    Comment: Two commenters agreed with EPA's proposed restrictions for
all types of self-contained ACIMs. Others disagreed, including one that
requested a 700 GWP limit for all self-contained equipment, regardless
of charge size. They stated that a 150 GWP limit would not be feasible,
given the limited charge sizes of A3 and A2L refrigerants allowed by
safety standards at public points of egress, and the insufficient
supply

available to OEMs of components with refrigerants with a GWP below 150
GWP. Another commenter stated that there is currently insufficient data
for setting restrictions that will comport with building codes, and
instead suggested applying the same list of prohibited substances
proposed for remote condensing ACIMs to self-contained ACIMs.
    Other commenters only supported the restrictions as proposed--a 150
GWP limit--for smaller (less than or equal to a 500 g charge, as
proposed) self-contained ACIMs. Of these commenters, some agreed with
the GWP limit set at a 500 g charge size, while one agreed with the
limit, but recommended setting the threshold at a harvest rate of 1,000
lb of ice per day instead of a charge size, and another approved of a
150 GWP limit, but only in very small self-contained equipment,
requesting a 114 g charge size threshold for setting restrictions,
instead. This commenter stated that R-290 is the only currently
feasible substitute for this type of equipment, and explained that in
certain circumstances, safety standards, SNAP use conditions, and
building codes limit its charge well below 500 g due to its
flammability. The commenter asserted that other options identified by
the Agency are either limited by toxicity concerns, refrigerant glide
technical challenges, a limited supply of components, or missing SNAP
listings, and therefore, the commenter argued that there are
insufficient available substitutes below 150 GWP for self-contained
ACIM with charge sizes greater than 114 g.
    Many of these same commenters, although supportive of the 150 GWP
limit for smaller self-contained ACIMs, disagreed with the proposed
restrictions for larger (above 500 g, as proposed) equipment. One
requested removing R-410A from the list of prohibited substances for
larger self-contained equipment, but only if sufficient time was
allowed. They explained that for certain larger ACIM, there are
currently no suitable SNAP-approved substitutes for R-410A. However,
they noted that prohibiting the use of R-410A would be appropriate if
provided additional time to comply, and that once the supply of
components to replace R-410A has improved, a 700 GWP limit could be
appropriate for this type of equipment. Other commenters requested a
2,500 GWP limit in place of a prohibited substances list.
    Several commenters supported the proposed list of prohibited
substances for use in remote condensing ACIM. Other commenters
disagreed. One commenter mentioned that removing R-404A from the
prohibited substances list would ease some of the immediate development
burden in remote models. Other commenters requested a GWP limit in
place of a prohibited substances list for remote condensing ACIMs. As
for larger self-contained ACIMs, two commenters requested a 2,500 GWP
limit, while, in contrast to all other comments received, another
commenter noted their support of a much lower 150 GWP limit.
    Response: In response to the comments received and its evaluation
of the availability of substitutes for use in this subsector, EPA is
finalizing all GWP and refrigerant-specific restrictions for ACIM as
proposed. Notably, the metric for distinguishing which restrictions
apply to different sizes of self-contained equipment has been changed
from the proposed rule, as described in this section above, but the GWP
limit for smaller units is finalized as proposed. EPA recognizes the
challenges for ACIMs used at points of egress for the public, but notes
that research and design for self-contained units with harvest rates
less than or equal to 1,000 lb of ice per day (batch type) and 1,200 lb
of ice per day (continuous type) that are able to use R-290 in
sufficiently small charges has been identified by commenters as already
underway. Many smaller self-contained units already use R-290, and with
a pending SNAP listing proposal to allow charges of R-290 up to 500 g,
EPA is confident in the industry's ability to meet a 150 GWP limit in
this type of equipment. Commenters also noted ongoing research to use
other SNAP proposed A2L refrigerants below 150 GWP, R-454C, and R-455A,
where an A3 refrigerant may not be feasible. Therefore, given the
additional year to comply, EPA considers a 150 GWP limit for self-
contained ACIM with harvest rates less than or equal to 1,000 lb of ice
per day (batch type) and 1,200 lb of ice per day (continuous type) as
appropriate, in agreement with many of the comments and other public
information.
    For self-contained ACIM with harvest rates greater than 1,000 lb of
ice per day (batch type) or 1,200 lb of ice per day (continuous type),
EPA appreciates the request by one commenter for a 700 GWP limit. At
this time, the Agency considers additional options with GWPs greater
than 700, particularly non-flammable refrigerants, as necessary,
because of the lack of available substitutes due to safety concerns
with large charge sizes of flammable refrigerants. However, as the
industry continues its transition away from some of the highest-GWP
refrigerants, EPA may choose to set a GWP limit for this type of
equipment at a later date. As noted by a second commenter, a limit
similar to 700 GWP may be appropriate in the future, depending on EPA's
evaluation of the availability of substitutes and their technological
achievability in larger self-contained ACIMs. EPA disagrees with
commenters who requested a 2,500 GWP limit in place of a list of
prohibited substances. Such a limit would allow for continued use of R-
410A (GWP 2,088) in self-contained equipment with higher harvest rates,
an HFC-blend refrigerant proposed as prohibited. Similarly, the Agency
disagrees with the commenter who asked for the list of prohibited
substances proposed for remote condensing ACIMs, which is less
restrictive than the list for larger self-contained equipment and does
not restrict R-410A, to apply to all types of ACIMs. Given there are
already several refrigerants listed by EPA's SNAP program for ACIMs
that are not prohibited, such as R-448A, R-449A, and R-449B, that SNAP
recently listed the nonflammable, azeotropic (minimal glide)
refrigerant R-515B, and that EPA has proposed to list several
additional refrigerants as acceptable for use in ACIM that are zero or
low glide and could serve as R-410A substitutes (e.g., HFC-32, R-454B),
EPA expects there will be a greater number available for use by the
extended date of compliance of January 1, 2027. Further, a commenter
explicitly noted that restricting the use of R-410A would be
appropriate if the Agency allotted additional time for component supply
to improve and to develop equipment using new substitutes. The Agency
therefore considers the industry capable of transitioning out of
certain specified higher-GWP HFCs and HFC blends, including R-410A, by
the compliance deadline.
    EPA agrees with many of the comments approving of the proposed list
of prohibited substances for use in remote condensing ACIMs. Regarding
the comments received requesting a 2,500 GWP limit, at this time, EPA
does not consider setting a GWP limit for this type of equipment to be
appropriate at this time but may choose to do so through future
rulemakings. By identifying HFCs and HFC blends as prohibited from use,
the Agency is able to encourage a transition away from specific higher-
GWP refrigerants while allowing flexibility for the industry as it
continues developing products that use refrigerants well below 2,500
GWP. As stated in section VI.B of this preamble, this approach--
restricting specific

substances instead of setting a GWP limit for a given subsector--gives
EPA time to identify an appropriate GWP limit for this subsector while
still restricting those substances that have the highest adverse
environmental impact. Given the additional technical challenges for
equipment installed remotely and restrictions on use of flammable
refrigerants in industry safety standards, the restricted list is less
prohibitive than that for self-contained units. EPA also disagrees with
the commenter that described a 150 GWP limit as appropriate for this
type of ACIM. Very few non-flammable substitutes are available below
150 GWP, flammability concerns are even greater for remote condensing
units than for those that are self-contained, and the information
provided did not support a conclusion that those nonflammable options
(e.g., R-744) are viable in all remote condensing ACIMs. For these
reasons, EPA is finalizing the restrictions for remote condensing ACIM
as proposed.
    Comment: One commenter supported EPA's proposed January 1, 2025,
compliance date for ACIM, citing California's HFC regulation
implementation as proof that 2025 is achievable. All other comments
received requested an extension from the proposed date, including
general requests for EPA to work with OEMs to ensure the achievability
of the timeline and additional time to develop new refrigerants, update
building codes, and harmonize with various standards, and for specific
compliance dates ranging from 2027 to 2029. Commenters who requested
2029 referenced the EU F-Gas Regulation's conversion timeline as one
reason for the appropriateness of a much later compliance date.
    Various issues were cited as reason for the requests to extend the
date of compliance from that proposed. Many manufacturers stated that
they will need to completely redesign many of their ACIM models, which
will take considerable time. Commenters described this subsector as
highly complex and diverse, with many varying demands. End-users range
from hospitals to restaurants, hotels, supermarkets, offices, and
schools, requiring many different types of ice, necessitating unique
equipment design for each model. New equipment development efforts,
according to a few commenters, will be held up by design challenges
unique to ACIM and vending machines, such as strict limitations on
flammable refrigerant charges at points of egress, which require
manufacturers to design for very small charge sizes. Additionally, the
availability of components, both in terms of supply chain and design of
models using new substitutes, was mentioned by several commenters as a
major challenge for this subsector to transition. Commenters
highlighted that after new models are designed, they will still need to
be tested and certified by NRTLs for safety, efficiency, and
sanitation.
    Commenters discussed how several identified substitutes have not
yet been SNAP-approved or updated to allow for larger charge sizes in
equipment, following the update to UL 60335-2-89. These commenters
stated that additional time would provide an opportunity for
finalization of SNAP listings, including new A2L refrigerants and
increased charge sizes for R-290, providing additional substitutes for
manufacturers to choose from. A few commenters requested a later
compliance date of January 1, 2029, for facilities not yet updated to
safely use flammable refrigerants to make necessary conversions. One
such commenter noted that an accelerated timeline to more flammable
options would create safety risks for manufacturers and the public
resulting from potential oversights and would not provide sufficient
time to train technicians to properly handle A3 refrigerants.
Commenters requested time for the new DOE efficiency standards for
ACIMs to be published, likely in 2027, before EPA requires compliance
with restrictions. This standard was described as greatly influential
on the design requirements of products, and if EPA sets a compliance
deadline ahead of its publication, commenters worried that they would
need to redesign their new products.
    Response: EPA agrees with commenters that additional time for
compliance is warranted for ACIMs to meet the restrictions finalized in
this rulemaking. ACIMs fall within the scope of safety standard UL
60335-2-89. In October 2021, the 2nd edition of this standard was
published, updating safety requirements so that flammable and lower
flammability refrigerants could be deployed more widely in commercial
refrigeration equipment. EPA recognizes the time it can take for an
updated UL standard to be widely incorporated and for the updates to be
applied across industry. Many other relevant changes affecting the
availability of substitutes and facilitating transition to the use of
those substitutes generally occur after the UL standard is updated,
including evaluation of substitutes under the SNAP program, adoption of
new editions of safety standards into building codes, equipment testing
and certification, safety updates to manufacturing facilities, and
training of technicians. All of these are considerations for EPA's
assessment of availability of substitutes under subsection (i)(4)(B).
Further discussion on how updates to UL 60335-2-89 affect the
availability of substitutes for equipment within the safety standard's
scope can be found in section VI.F.1.a.
    Typically, following updates to safety standards for commercial
refrigeration equipment, EPA evaluates substitutes through the SNAP
program's comparative risk framework, where the Agency considers safety
by assessing exposure assessments, toxicity data, and flammability, as
well as other regulatory criteria. EPA is currently evaluating many of
the refrigerants impacted by the updates to UL 60335-2-89 and has
proposed to list several refrigerants as acceptable, subject to use
conditions, under SNAP for use in ACIMs (88 FR 33722, May 24, 2023).
Although those evaluations under SNAP are ongoing, the Agency
anticipates that given the number of substitutes currently proposed as
acceptable for use, users in the ACIM subsector will likely have an
expanded set of available substitutes from which to choose in the
coming years. EPA has considered its ongoing ACIM evaluations under
SNAP, the adjusted compliance timeframes reflecting these evaluations,
and their potential impact on the availability of substitutes for use
in this subsector, as well as the existing acceptable substitutes that
are not prohibited, in finalizing the restrictions for ACIMs. Further
discussion on the intersection of SNAP listing decisions and AIM Act
subsection (i)(4) criteria can be found in section VI.E.
    As noted by many commenters, building codes can limit refrigerants
available for use based on their flammability, the charge size of the
equipment, and other relevant safety factors, and take time to adopt
changes to safety standards. These code updates are generally made in
each specific jurisdiction, and the timeframe for adoption of new
editions of safety standards can vary greatly. In certain
jurisdictions, users may be unable to utilize certain flammable
substitutes identified by EPA for use in ACIMs, even if they are SNAP-
approved, until building codes incorporate the updates in the 2nd
edition of UL 60335-2-89. However, EPA may still consider a substitute
to be available before every building code in every jurisdiction across
the United States permits its use. See section VI.E.2.d for discussion
on EPA's consideration of building codes and the availability of
substitutes under subsection (i)(4).

    Further, EPA agrees with commenters that updates to UL standards
and new listings under SNAP must also be incorporated into equipment
design, testing, and certifications. Even after manufacturers develop
equipment using substitutes, NRTLs must certify that the new equipment
meets UL safety standards. NRTL equipment certification requires
substantial testing, site visits, and labor input before new equipment
can be used. Although ACIM is a smaller subsector, all commercial
refrigeration equipment expanding use of flammable refrigerants will
need to be tested, and NRTLs could struggle to complete certification
of new equipment by the proposed January 1, 2025, compliance date for
this subsector. However, the industry seems to anticipate this upcoming
need and is opening or expanding testing labs to handle this
demand.\131\
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    \131\ See, e.g., https://www.danfoss.com/en/about-danfoss/news/dcs/new-extension-of-danfoss-atex-lab-accelerates-the-use-of-sustainable-refrigerants.
---------------------------------------------------------------------------

    EPA also anticipates that greater use of flammable refrigerant
options like R-290 and A2Ls that EPA's SNAP program has proposed as
acceptable for use in ACIM may require more specialized training.
Trainings on flammable refrigerants have been available for many years,
and there are now trained technicians within the commercial
refrigeration industry in general whose knowledge and skills will
assist the transition to lower-GWP refrigerants in other related
subsectors.
    EPA agrees with the commenters that manufacturing facilities not
currently using flammable refrigerants will need to incorporate safety
updates before using flammable refrigerants on site. The Agency
acknowledges that these upgrades to manufacturing facilities could
require financial and time investments; however, the use of A2L and A3
refrigerant has steadily increased over the last ten years, meaning
many manufacturers may have already made such upgrades, or intend to do
so in the coming years. In the cases where these updates have yet to be
made, EPA understands that they could delay when industry is able to
factory-charge new substitutes into their appliances, which is one
factor we considered in establishing 2026 and 2027 compliance dates for
this subsector.
    For self-contained batch type ACIMs with harvest rates less than or
equal to 1,000 lb of ice per day, and for self-contained continuous
type ACIM with harvest rates less than or equal to 1,200 lb of ice per
day, EPA is finalizing a January 1, 2026, compliance date. EPA has
proposed to update the SNAP use conditions for R-290 use in ACIMs and
to list A2L refrigerants that meet the GWP limits for this type of
ACIM. Finalizing an additional year to comply with the restrictions
under subsection (i) provides more time for that ongoing evaluation
under SNAP, for designers to develop equipment using up to 500 g of R-
290 (a significant increase from the currently allowed 150 g), and for
compressor manufacturers and OEMs to begin developing products with A2L
refrigerants. This extra time is also provided to allow OEMs to
continue research and development of equipment using smaller charge
sizes of flammable refrigerants (less than 114 g for R-290) that would
comply with building codes at points of egress in public spaces. A
large portion of the self-contained equipment market with lower harvest
rates has already transitioned to lower-GWP options, especially R-290,
meaning that fewer models will need to be redesigned to meet the
restrictions. Therefore, in our evaluation of the (i)(4)(B) criteria
and for the reasons discussed, EPA finds that January 1, 2026, is an
appropriate compliance date for self-contained ACIMs with harvest rates
equal to or below 1,000 lb ice per 24 hours (batch type) or 1,200 lb
ice per 24 hours (continuous type).
    For self-contained ACIMs with harvest rates greater than 1,000 lb
of ice per day (batch type) or 1,200 lb of ice per day (continuous
type) and for remote condensing ACIMs, EPA is finalizing a January 1,
2027, compliance date. EPA understands that in equipment with larger
charge sizes, flammability concerns are greater, creating additional
design challenges related to building codes and safety standards. In
remote condensing ACIMs, the refrigerant circulates in and out through
piping that has been installed in the field that is more prone to leaks
than self-contained equipment, also adding to the risk of using
flammables. For this reason, considerably fewer products in these
categories of ACIMs have transitioned from their respective lists of
prohibitive substances, requiring substantial redesigns of equipment
before the restrictions are able to be met. Given the diversity of ACIM
end-users and the complexity of design in terms of varying ice shapes,
EPA is providing two additional years from the date proposed for the
industry to research, develop, test, and certify new equipment using
refrigerants other than those prohibited. Similar to smaller, self-
contained ACIMs, extending the compliance date will provide opportunity
for additional substitutes to become available for manufacturers, such
as those under evaluation in proposed SNAP Rule 26. A later date will
likely also grant time for publication of DOE's new efficiency standard
for ACIMs, which will inform how OEMs choose to design new equipment.
    The Agency disagrees with selecting a compliance date based on
other regulations, such as the EU F-Gas Regulation or the proposal to
revise that regulation.\132\ The AIM Act compels EPA to set deadlines
for restrictions based on the availability of substitutes in
consideration of the factors described in subsection (i)(4), not based
on decisions made by other regulatory bodies. Therefore, EPA is
finalizing the compliance dates for ACIMs earlier than January 1, 2029,
after evaluating the availability of substitutes and the feasibility of
the U.S. industry to transition by an earlier date.
---------------------------------------------------------------------------

    \132\ The Agency's review of the EU F-Gas rule is that self-
contained ACIMs have been subject to a 2,500 GWP limit since January
1, 2020, and the proposed rule would subject them to a 150 GWP limit
beginning January 1, 2025.
---------------------------------------------------------------------------

    EPA has therefore determined, in consideration of the subsection
(i)(4)(B) criteria and the potential for certain SNAP approvals;
updates to building codes; equipment design, testing, and
certifications; technician trainings; and manufacturing facility
upgrades, that providing additional time to comply is reasonable for
ACIMs. Considering these factors, noted by many commenters, the Agency
is finalizing extended compliance dates for this subsector to provide
time for ongoing SNAP evaluation; jurisdictions to consider the latest
edition of UL 60335-2-89 and incorporate the updated safety
requirements into their building codes to enable the use of certain
substitutes; further development, testing, and certification of
equipment using new substitutes; a greater number of specialized
trained technicians; and completion of remaining safety updates to
facilities.
h. Refrigerated Transport
    The refrigerated transport subsector primarily moves perishable
goods (e.g., food, flowers) and pharmaceuticals at temperatures between
-22 [deg]F (-30 [deg]C) and 61 [deg]F (16 [deg]C) by various modes of
transportation, including aircraft, roads and railways, vessels, and
intermodal containers. For this action, EPA is establishing
restrictions in three distinct subsectors: road, marine, and intermodal
containers.
    Refrigerated transport--road consists of refrigeration for
perishable goods in refrigerated vans, trucks, or trailers and

is the most common mode of refrigerated transport in the United States.
This mode includes refrigerated trucks and trailers with a separate
autonomous refrigeration unit with the condenser typically located at
the front of a refrigerated trailer. This subsector also covers
domestic trailer refrigeration units that contain an integrated motor
(i.e., does not require a separate electrical power system or separate
generator set to operate) that are transported as part of a truck, on
truck trailers, and on railway flat cars. Other types of containers,
such as seagoing ones that are connected to a vessel's electrical
system or require a separate generator that is not an integral part of
the refrigeration unit to operate, are not included. This subsector
also does not include: (i) Refrigerated vans or other vehicles where a
single system also supplies passenger comfort cooling (MVAC), (ii)
refrigerated containers that are less than 8 feet 4 inches in width,
(iii) refrigeration units used on containers that require a separate
generator to power the refrigeration unit, or (iv) ship holds
(refrigerated transport--marine).
    Refrigerated transport--marine consists of refrigeration for
cooling and storage of perishable goods on refrigerated vessels and
various modes of transportation via water, including merchant, naval,
fishing, and cruise-shipping. This subsector includes refrigerated ship
holds and seagoing containers that are connected to a vessel's
electrical system or require a separate generator to operate that is
not an integral part of the refrigeration unit. This subsector excludes
refrigerated containers that contain their own power source and
refrigerators or freezers that are plug-in appliances designed for
retail food refrigeration (e.g., stand-alone units used in a galley or
store).
    Lastly, refrigerated transport--intermodal containers are
refrigerated containers with an integrated power source that allow
uninterrupted storage during transport on different mobile platforms,
including railways, road trucks, and vessels. A common example of
intermodal containers are standard-sized refrigerated containers that
follow the International Organization for Standardization standard 668,
``Series 1 freight containers--Classification, dimensions and
ratings.''
    Other types of refrigerated transport exist (e.g., refrigerated box
cars for use in rail, and intermodal refrigerated containers operating
at temperatures lower than -50 [deg]C (-58 [deg]F) for carrying food,
medicine, or vaccines at very low temperatures), but EPA is not
establishing restrictions on HFC refrigerants in this rule for those
other types.
    Refrigerated transport equipment manufacturers have used HFC
refrigerants, mainly R-404A and HFC-134a, after the phase out of ozone-
depleting CFC and HCFC refrigerants such as R-12 and R-22.
    This section provides EPA's final restrictions for each of the
three subsectors within the refrigerated transport subsector, followed
by significant comments regarding the entire refrigerated transport
subsector and EPA's responses to those comments.

What restrictions on the use of HFCs is EPA establishing for
refrigerated transport--road?

    EPA is prohibiting the use of HFCs in the following blends in new
refrigerated transport-road equipment beginning January 1, 2025: R-
402A, R-402B, R-404A, R-407B, R-408A, R-410B, R-417A, R-421A, R-421B,
R-422A, R-422B, R-422C, R-422D, R-424A, R-428A, R-434A, R-438A, R-507A,
R-125/290/134a/600a (55/1/42.5/1.5), RS-44 (2003 formulation) and GHG-
X5.
    Similar to EPA's approach in addressing the use of HFCs in specific
blends in remote condensing ACIM, EPA is not establishing a GWP limit
for refrigerated transport--road and instead is restricting the use of
HFCs in specific blends. A GWP limit of 2,200, as requested in one of
the petitions that EPA granted, is high compared to the GWP limit that
the Agency is establishing in other commercial refrigeration
applications, and the Agency intends to propose a GWP limit at a later
time. As stated in section VI.B of this preamble, this approach--
restricting specific substances instead of setting a GWP limit for a
given subsector--gives EPA time to identify a GWP limit while still
restricting those substances that have the highest environmental impact
(e.g., R-404A, with a GWP of 3,922, is a commonly used refrigerant in
this subsector that EPA is restricting). For its considerations of
availability of substitutes under subsection (i)(4)(B), EPA identified
substitutes that are available in place of the substances that EPA is
restricting. These include R-744 (GWP 1), R-450A (GWP 601), R-513A (GWP
630), and R-452A (GWP 2,140). Cryogenic transport refrigeration systems
and direct nitrogen expansion are other existing technologically
achievable options. Cryogenic systems cool cargo by injection of stored
liquid R-744 or nitrogen (R-728) into the cargo space or an evaporator.
These systems are used in small and large trucks, primarily in Northern
Europe. In recent years manufacturers have also developed equipment
using R-452A. R-452A has similar properties to R-404A, including
cooling capacity, reliability, refrigerant charge, non-flammability,
and low compressor discharge temperatures, supporting its use as a
lower-GWP and technologically achievable substitute. The two major
U.S.-based manufacturers of refrigeration equipment for refrigerated
transport--road currently offer equipment using R-
452A.133 134 EPA considers usage in the market as an
indication of the commercial demands and technological achievability of
a substitute.
---------------------------------------------------------------------------

    \133\ Thermo King to Reduce Global Warming Potential of
Transport Refrigeration by Nearly Fifty Percent, Thermo King,
January 2022. Available at: https://www.thermoking.com/na/en/newsroom/2022/01-jan/thermo-king-to-reduce-global-warming-potential-of-transport-refr.html.
    \134\ Carrier Transicold Strengthens Sustainability Initiatives
with Lower GWP Refrigerant for North America Truck and Trailer
Systems, Carrier Transicold, December 2020. Available at: https://www.carrier.com/truck-trailer/en/north-america/news/news-article/carrier_transicold_strengthens_sustainability_initiatives_with_lower_gwp_refrigerant_for_north_america_truck_and_trailer_systems.html.
---------------------------------------------------------------------------

What restrictions on the use of HFCs is EPA establishing for
refrigerated transport--marine?

    EPA is restricting the use of the following HFCs and blends
containing HFCs in new refrigerated transport--marine systems beginning
January 1, 2025: R-402A, R-402B, R-404A, R-407B, R-408A, R-410B, R-
417A, R-421A, R-421B, R-422A, R-422B, R-422C, R-422D, R-424A, R-428A,
R-434A, R-438A, R-507A, R-125/290/134a/600a (55/1/42.5/1.5), RS-44
(2003 formulation) and GHG-X5. EPA is not establishing a GWP limit at
this time and the list of prohibited HFCs and blends containing HFCs
are the same as in refrigerated transport--road. EPA's rationale for
restricting specific substances in this subsector can be found in
section VI.B, with additional information in section VI.F.3.e (under
the restrictions on the use of HFCs in ACIM).
    Available substitutes that may be used in refrigerated transport--
marine in place of the substances that EPA is restricting include R-
717, R-744, R-450A, and R-513A. Marine transport refrigeration systems
cover a wide range of merchant, naval, fishing, and cruise-shipping
applications and often require specialized and custom refrigeration
equipment. Historically, this sector used R-22, R-404A, R-507A, R-407C,
and R-134a. Today, manufacturers market lower-GWP substitutes for
marine applications such as R-717 and R-744,

either alone or in cascade systems, particularly for fishing vessels,
but these substitutes are not necessarily available in all applications
within this subsector. According to the Refrigeration, Air Conditioning
and Heat Pumps Technical Options Committee (RTOC), HFC/HFO blends with
lower GWPs may also be suitable for some applications and system
designs; in addition, the International Maritime Organization limits
the GWP of refrigerant in new equipment at 2,000.\135\
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    \135\ Refrigeration, Air Conditioning, and Heat Pumps Technical
Options Committee 2018 Assessment Report, Technical and Economic
Assessment Panel, UNEP, February 2019. Available at: https://ozone.unep.org/sites/default/files/2019-04/RTOC-assessment-report-2018_0.pdf.
---------------------------------------------------------------------------

What restrictions on the use of HFCs is EPA establishing for
refrigerated transport--intermodal containers?

    EPA is restricting the use of HFCs and blends containing HFCs that
have a GWP of 700 or greater for new refrigerated transport--intermodal
containers with refrigerant temperatures entering the evaporator, or
exiting fluid temperatures from a chiller, at or above -50 [deg]C (-58
[deg]F), beginning January 1, 2025. For new refrigerated transport--
intermodal containers with refrigerant temperatures entering the
evaporator, or exiting fluid temperatures from a chiller, below -50
[deg]C (-58 [deg]F), there are no restrictions in this final rule.
    For its considerations of availability of substitutes under
subsection (i)(4)(B), EPA identified substitutes that are available in
place of the substances that EPA is restricting. These include R-744
and R-450A. R-513A, R-513B, and R-456A are also potential candidates.
According to the RTOC, thousands of intermodal containers operating
with R-744 were purchased or leased in 2016 and 2017,\136\ and EPA
identified one manufacturer that offers an intermodal container using
R-744.\137\ Several manufacturers also offer intermodal containers
using R-513A for new and retrofit applications.138 139 140
---------------------------------------------------------------------------

    \136\ Ibid.
    \137\ Carrier Transicold ``NaturaLINE'' products. Additional
information available at: https://www.carrier.com/container-refrigeration/en/worldwide/products/Container-Units/naturaline.
    \138\ Maersk Container Industry, Star Cool--Refrigerants.
Available at: https://www.mcicontainers.com/products/star-cool/refrigerants.
    \139\ Carrier Transicold Offers Lower GWP Refrigerant Option for
PrimeLINE[supreg] Container Units, Carrier Transicold, February
2018. Available at: https://www.carrier.com/container-refrigeration/en/worldwide/news/news-article/carrier_transicold_offers_lower_gwp_refrigerant_option_for_primeline_container_units.html.
    \140\ Thermo King, Container Fresh and Frozen. Available at:
https://www.thermoking.com/na/en/marine/refrigeration-units/container-fresh-and-frozen.html.
---------------------------------------------------------------------------

    Comment: Several commenters supported a GWP limit of 700 for HFCs
and blends containing HFCs used in new refrigerated transport--
intermodal containers. One of these commenters urged EPA to maintain
the listed requirement, stating that transport refrigeration systems
are a significant source of HFC emissions. Another commenter
recommended the following adjustments to the 700 GWP limit for
intermodal containers to account for operating needs at different
temperature ranges:

a. for operating temperature above -58 [deg]F (-50 [deg]C), GWP limit
of 700
b. for operating temperature in the range of -58 [deg]F (-50 [deg]C) to
-103 [deg]F (-75 [deg]C), GWP limit of 2,000
c. for operating temperature below -103 [deg]F (-75 [deg]C), GWP limit
is exempted
    The commenter encouraged EPA also to adopt a GWP limit of 2,000 for
new refrigerated transport--intermodal containers where the temperature
of the chilled fluid leaving the chiller is lower than -50 [deg]C,
which is consistent with EPA's treatment of not applying a GWP limit of
700 for chillers for IPR with exiting fluid temperatures lower than -50
[deg]C. This commenter also stated that refrigerants used in low
temperature chillers (i.e., below -50 [deg]C) have high GWPs (e.g.,
HFC-23 with a GWP of 14,800, R-508B with a GWP of 13,396), and this is
also true for low temperature intermodal containers. The same commenter
stated that they have developed a refrigerant for this temperature
range with a GWP of 1,831.
    Response: EPA is establishing restrictions on HFCs and HFC blends
with a GWP of 700 or higher for use in new refrigerated transport--
intermodal containers, as proposed. Manufacturers are already selling
intermodal containers using R-744 (GWP 1), R-450A (GWP 601), and R-513A
(GWP 630), indicating the availability of these substitutes for use in
this subsector, particularly with regard to technological achievability
and commercial demand. Concerning the comments about refrigerated
transport--intermodal containers with exiting fluid at temperatures
below -58 [deg]F (-50 [deg]C), in this final rule, EPA is not
establishing GWP restrictions for refrigerated transport--intermodal
containers with fluid temperatures below -50 [deg]C (-58 [deg]F). (For
chiller type equipment, this is the fluid leaving the system, and for
direct expansion equipment, this is the temperature of the refrigerant
as it enters the evaporator.) EPA recognizes that most of the
refrigerants used for equipment with fluid temperatures below -50
[deg]C (-58 [deg]F) have relatively high GWPs. Upon evaluating the
availability of substitutes for refrigerated transport--intermodal
containers operating at very low temperatures, EPA is not restricting
the use of HFCs and HFC blends with exiting fluid temperatures lower
than -50 [deg]C (-58 [deg]F) in this final rule. EPA notes that there
is a similar lack of availability of refrigerants with temperatures
either entering the evaporator or exiting a chiller or low temperature
stage in other subsectors, such as IPR and chillers for IPR. The Agency
expects that after further research and development, there may be
additional refrigerants available for these low temperatures, after
additional reviews of refrigerants for safety, health, and
environmental impacts under the SNAP program and further development of
industry standards that would allow for use of flammable refrigerants.
Note that EPA may choose to set restrictions in the future as the
availability of lower-GWP substitutes continues to grow.
    Comment: One commenter generally supported the proposed refrigerant
bans for ``transport refrigeration--road'' for refrigerated transport:
truck, trailer, aircraft, and rail. Another commenter suggested that
EPA harmonize the GWP limit of all transport refrigeration including
truck and trailer, rail, and construction (although the commenter did
not refer to intermodal or marine), with refrigerant bans listed for
road systems and a January 1, 2025, transition date. Another commenter
generally supported the restrictions for refrigerated transport for
marine and road applications. This commenter also stated that they
preferred that EPA restrict use of refrigerants with 2,200 GWP limit or
higher, rather than specific listings of HFCs for these subsectors,
stating this would standardize the approach across sectors, align with
CARB regulations, and still enable EPA to set a lower GWP limit at a
future date. Another commenter stated that a transition toward A2L
refrigerants and other lower-GWP alternatives in these subsectors is
underway in various States and in other countries and that the proposed
rule continues this progress by imposing specific HFC bans with respect
to transport refrigeration used in road systems and marine. This
commenter encouraged EPA to do more, specifically stating that EPA
should develop future technological transitions rulemakings that set
GWP limits--significantly lower than 2,200--for these transport--
refrigeration subsectors as soon as EPA determines that lower-GWP
alternatives meeting the criteria set forth

in subsection (i)(4) of the AIM Act have become available.
    One commenter stated that the proposed list of banned refrigerants
for refrigerated transport could be reasonable, provided R-452A is
listed as approved well before the transition. They commented that
ASHRAE class A1 refrigerants must be available for transport
refrigeration equipment. This commenter suggested that marine
applications could also be regulated for the same list of HFCs that are
being regulated under other refrigerated transport subsectors
(mentioning truck, trailer, aircraft, and rail) if there were an
allowance for the use of R-452A for frozen cargo. They stated that HFC-
134a is only used for marine and self-contained equipment and could be
added to the list of restricted refrigerants.
    Response: In this final rule, EPA is establishing a restriction on
specific HFCs and HFC blends as proposed for transport refrigeration--
marine and transport refrigeration--road. The specific HFCs and HFC
blends restricted for these subsectors are R-404A, R-507, R-507A, R-
428A, R-422C, R-434A, R-421B, R-408A, R-422A, R-407B, R-402A, R-422D,
R-421A, R-125/290/134a/600a (55/1/42.5/1.5), R-422B, R-424A, R-402B,
GHG-X5, R-417A, R-438A, R-410B, IKON A, IKON B, R-134a/HBr (92/8), RS-
44 (2003 formulation), THR-02, THR-03, and THR-04. This list consists
of all refrigerants with a GWP greater than 2,200 previously listed as
acceptable under SNAP. Thus, at this time, the list of specific
substances corresponds to the GWP limit 2,200 in CARB's regulations and
avoids complications because of differences.
    Concerning the comment requesting that EPA harmonize the GWP limit
of all transport refrigeration, including truck and trailer, rail, and
construction, with refrigerant bans listed for road systems and a
January 1, 2025, transition date, EPA understands the comment to mean
that EPA should set restrictions on the same list of refrigerants, all
of which have GWPs over 2,200, for all refrigerated transport used on
road or rail. For other road or rail uses that EPA excluded from the
proposed description of ``transport refrigeration--road,'' such as
refrigerated box cars for rail use, refrigerated containers that are
less than 8 feet 4 inches in width, or refrigeration units used on
containers that require a separate generator to power the refrigeration
unit, because these uses fall outside the description of ``refrigerated
transport--road'' in the proposed rule, EPA does not consider them to
fall under the refrigerant restrictions in this final rule. However,
EPA may establish GWP restrictions or specific refrigerant restrictions
for these uses in the future. All of the restricted refrigerants are A1
refrigerants, as are the alternative refrigerants that SNAP has listed
as acceptable for refrigerated transport to date. Further, by not
restricting R-452A, the list of restricted HFCs allows for use of that
refrigerant until lower-GWP refrigerants that can be used safely in
mobile applications are available. EPA agrees that in the future, the
Agency could set a GWP limit, once EPA identifies that lower-GWP
alternatives meeting the criteria set forth in subsection (i)(4) of the
AIM Act have become available. EPA is not setting a GWP limit at this
time for transport refrigeration--marine and transport refrigeration--
road because EPA's assessment is that there continues to be significant
development of new refrigerants with lower GWPs than 2,200 for use in
these subsectors. Restricting those substances that have the highest
environmental impact provides environmental protection while giving
industry time to develop new lower-GWP refrigerants.
    Comment: One commenter strongly advised EPA to reconsider the
January 1, 2025, compliance date for retail refrigeration units, cold
storage warehouse systems, and transport refrigeration due to a lack of
available replacement technology sufficient for a wide-scale retail
industry transition and extraordinary cost burdens associated with the
proposed limits. This commenter expressed concern that a single break
in the chain between farmers, manufacturers, and transportation
companies would ripple through the entire supply chain and ultimately
harm consumers. A different commenter urged EPA to maintain the
timeline for refrigerated transport. This commenter stated that a
transition toward A2L refrigerants and other lower-GWP alternatives in
these subsectors is underway in various States and in other countries.
    Response: EPA is establishing a compliance date of January 1, 2025,
for refrigerated transport (road, marine, and intermodal containers) in
the final rule, as proposed. As mentioned above, lower-GWP alternatives
that would allow regulated parties in these three subsectors to meet
the final restrictions are already available and are being used for
refrigerated transport (e.g., R-744, R-450A, R-513A, R-452A). It is
EPA's understanding that the U.S. manufacturers of refrigerated
transport equipment are no longer using the higher-GWP blends that are
restricted in this rule to manufacture the covered types of equipment.
EPA expects that there will be sufficient amounts of alternative
refrigerants to meet the commercial demand for refrigerated transport
equipment, since this is a relatively small market for refrigerant
compared to stationary commercial refrigeration.
i. Household Refrigerators and Freezers
    Household refrigerators, freezers, and combination refrigerator/
freezers are refrigeration appliances intended primarily for
residential use, although they may be used outside the home. These
products may also be referred to as ``residential refrigeration.''
\141\ The designs and refrigeration capacities of equipment vary
widely. Household freezers only offer storage space at freezing
temperatures, while household refrigerators only offer storage space at
non-freezing temperatures. Products with both a refrigerator and
freezer in a single unit are most common. For purposes of this rule,
other small, refrigerated household appliances such as chilled kitchen
drawers, wine coolers, household ice makers, and minifridges also fall
within this subsector. Household refrigerators and freezers have all
refrigeration components integrated, and for the smallest types, the
refrigeration circuit is entirely brazed or welded. These products are
charged with refrigerant at the factory and typically require only an
electricity supply to begin operation.
---------------------------------------------------------------------------

    \141\ In the proposed rule EPA used the term ``residential
refrigeration systems.'' For clarity, EPA is using ``household
refrigerators and freezers'' to better indicate that these are
products and not systems under the terminology of this rule. The
term ``domestic refrigeration'' may also be used to indicate
refrigeration within a domicile and is not intended to relate to the
country of manufacture or use.
---------------------------------------------------------------------------

    CFC-12 was a commonly used refrigerant in household refrigerators
and freezers prior to the Montreal Protocol and subsequent CAA
restrictions on CFCs. The household refrigeration industry transitioned
to HFC-134a and hydrocarbon refrigerants. According to the RTOC 2022
assessment report, R-600a (isobutane) is used in 75 percent of all new
household refrigerators and freezers globally with HFC-134a used in the
remaining 25 percent.

What restrictions on the use of HFCs is EPA establishing for household
refrigerators and freezers?

    EPA is restricting the use of HFCs and blends containing HFCs that
have a GWP of 150 or greater for new household refrigerators and
freezers manufactured or imported beginning January 1, 2025, as
proposed. Sale,

distribution, offer for sale or distribution, and export of new
household refrigerators and freezers using HFCs and HFC blends with a
GWP of 150 or greater is prohibited beginning January 1, 2028.
    EPA is establishing the 150 GWP limit and the January 1, 2025,
compliance date after considering the AIM Act subsection (i)(4)
factors, and in particular, after determining that there are a number
of available substitutes with 150 GWP or lower for use in new household
refrigerators and freezers. These include R-290 (GWP 3.3), R-600a (GWP
1), R-441A (GWP 3), and HFC-152a (GWP 124). These lower GWP options
have been available for a few years now following the publication of UL
60335-2-24 in 2017, which allowed for larger charge size of R-290 and
other R-600a from 57 g to 150 g. See the Availability of Substitutes
TSD for further information on available HFC and HFC-blend substitutes
for household refrigerators and freezers.
    In particular, EPA has found that R-600a is already a widely
available and widely used substitute in this subsector. According to
the TEAP and its RTOC, R-600a is the main energy-efficient and cost-
competitive substitute that is used globally in household refrigeration
as it is ``. . . the ideal refrigerant for domestic refrigeration
products, giving roughly 5 percent higher efficiency than HFC-134a
while at the same time reducing the noise level of the unit.'' \142\
This report also indicated that globally, household refrigerators are
already predominantly using R-600a. For the U.S. market, RTOC reports
substantial progress in converting from HFC-134a to R-600a with the
market introduction of small refrigerators and freezers that typically
do not use electricity to defrost and noted that a major U.S.
manufacturer introduced auto-defrost refrigerators using R-600a
refrigerant to the U.S. market as early as 2010. Given the widespread
global and growing domestic use of R-600a as referenced in the 2022
TEAP report, EPA finds that R-600a is available per subsection
(i)(4)(B), particularly with respect to technological achievability,
commercial demand, safety, and cost.
---------------------------------------------------------------------------

    \142\ TEAP 2022 Progress Report (May 2022) and 2018 Quadrennial
Assessment Report are available at: https://ozone.unep.org/science/assessment/teap; the 2018 Quadrennial Assessment Report includes
sections for each of the TOCs: Flexible and Rigid Foams TOC, Halons
TOC, Methyl Bromide TOC, Medical and Chemicals TOC, and
Refrigeration, Air Conditioning and Heat Pumps TOC.
---------------------------------------------------------------------------

    Across the United States and globally, the transition from HFC-134a
is already well underway, indicating that there are sufficient
available substitutes to use in place of that refrigerant. Several
States have banned the use of HFC-134a refrigerant in household
refrigerators and freezers, including California, Colorado, Delaware,
Maine, Maryland, Massachusetts, New Jersey, New York, Rhode Island,
Virginia, Vermont, and Washington. These restrictions became effective
between 2021 and 2023. Globally, the EU has prohibited refrigerants
that contain HFCs with a GWP greater than 150 in household
refrigerators and freezers since January 1, 2015.\143\ These existing
regulatory requirements indicate that lower-GWP substitutes are already
available, as discussed in section VI.E.
---------------------------------------------------------------------------

    \143\ For additional information, the EU legislation to control
F-gases web page is available at: https://ec.europa.eu/clima/eu-action/fluorinated-greenhouse-gases/eu-legislation-control-f-gases_en.
---------------------------------------------------------------------------

    Comment: Only one commenter expressed concerns with EPA's proposed
150 GWP limit for this subsector. The commenter stated it was
unnecessary and potentially unrealistic and suggested a 300 GWP limit
for household refrigeration.
    Response: EPA is finalizing a 150 GWP limit for household
refrigerators and freezers as proposed. The Agency disagrees with the
commenter's assertion that 150 is unnecessary or unrealistic. The
commenter did not provide information disputing the substitutes EPA
identified at proposal as available for use in this subsector, per
subsection (i)(4)(B). The Agency does not agree that a 300 GWP limit is
reasonable upon consideration of the (i)(4) factors. Many refrigerant
options with GWPs lower than 300 in fact lower than 150 are already
being used in this subsector in the United States, including R-290 and
R-600a. As is often the case, certain subsectors coalesce around the
use of a particular option, and according to the TEAP and its RTOC, R-
600a is the dominant refrigerant in this subsector.
j. Chillers
    A chiller is a type of equipment using refrigerant to typically
cool water or a brine solution that is then pumped to fan coil units or
other air handlers to cool the air that is supplied to occupied spaces.
The heat absorbed by the water or brine can then be used for heating
purposes and/or can be transferred directly to the air (``air-
cooled''), to a cooling tower or body of water (``water-cooled''), or
through evaporative coolers (``evaporative-cooled''). A chiller or
group of chillers are similarly used for district cooling where a
chiller plant cools water or another fluid that is then pumped to
multiple locations being served, such as several office or educational
buildings within the same complex. Although typically used for cooling,
chillers may also be used to provide heating, for instance by
extracting heat from ambient air and transferring it via a working
fluid distributed to heaters throughout a building. Chillers may also
be used to maintain operating temperatures in various types of
buildings; for example, in pharmaceutical, agricultural, and food
operations. Chillers have also been used to create ice, such as in an
ice-skating arena, and have been employed to maintain equipment
reliability, for instance in data centers.
    Chillers are also used to cool process streams in industrial
applications; in such instances, these are regulated as ``chillers for
industrial process refrigeration'' as discussed here and not as
``industrial process refrigeration'' as discussed in section VI.F.1.a.
Chillers are also used for comfort cooling of operators or climate
control and protecting process equipment in industrial buildings, for
example, in industrial processes when ambient temperatures could
approach 200 [deg]F (93 [deg]C) and corrosive conditions could exist.
    Given the breadth of how chillers are employed, our analysis of the
subsection (i)(4) factors leads us to find different GWP limits and/or
different compliance dates to be appropriate for different applications
of chillers. EPA provided some distinction of such chillers in the
proposed rule and is finalizing those and other distinctions based on
information from commenters. This rule addresses the multiple types of
chillers as they are used in particular subsectors, including chillers
used to provide cooling of electronics such as data servers in data
centers, ITEFs, and computer room cooling equipment (see section
VI.F.1.b), chillers used in cold storage warehouses, e.g., to maintain
temperature for fresh or frozen food and pharmaceuticals (see section
VI.F.1.e), chillers used to create and maintain ice, for instance in
ice-skating rinks or toboggan or luge tracks (see section VI.F.1.f),
chillers used to provide comfort cooling or heating (discussed below),
and chillers used for industrial process cooling (discussed below). Our
review of the (i)(4) factors also provides the basis for distinguishing
chillers by the temperature of the fluid exiting the chiller, while
maintaining some consistency in GWP limits and/or compliance dates
across different chiller applications. EPA notes that the distinctions
made in this rule are more specific than in other EPA regulations,

such as those under sections 608 and 612 of the CAA.\144\
---------------------------------------------------------------------------

    \144\ In describing these regulations promulgated under
authorities of title VI of the CAA, EPA is neither reopening nor
revisiting them.
---------------------------------------------------------------------------

    There are several different types of mechanical commercial comfort
cooling AC systems known as chillers, which use refrigerants in a vapor
compression cycle or by alternative technologies. Vapor compression
chillers can be categorized by the type of compressor, including
centrifugal and positive displacement chillers. Centrifugal chillers
are typically used for commercial comfort AC, although other uses
exist. Centrifugal chillers tend to be used in larger occupied
buildings such as office buildings, hotels, arenas, convention halls,
and airport terminals. Positive displacement chillers utilize positive
displacement compressors such as reciprocating, screw, scroll, or
rotary types. Positive displacement chillers are applied in similar
situations as centrifugal chillers, again primarily for commercial
comfort AC, except that positive displacement chillers tend to be used
for smaller capacity needs such as in mid- and low-rise buildings.
    A chiller may be either a product that is fully completed and
charged at a factory or a component that is installed into a field-
charged system. Typically, chillers with larger charge capacities are
charged in the field. The GWP limits and compliance dates discussed in
this section for chillers apply irrespective of whether the chiller is
a product or a system. Chillers that are products, as with all other
products, have a three-year sell-through. Chillers that are components
of systems, as with all other components, are not subject to the
restrictions on manufacturing, import, sale, distribution, and export,
but new systems using chillers may not be installed after the
compliance date.

What restrictions on the use of HFCs is EPA establishing for chillers--
comfort cooling?

    EPA is restricting the use of HFCs and blends containing HFCs that
have a GWP of 700 or greater for chillers--comfort cooling beginning
January 1, 2025. This GWP limit applies to new equipment for all
compressor types of chillers--comfort cooling, i.e., centrifugal and
positive displacement (including reciprocating, screw, scroll, and
rotary) chillers.
    For its consideration of the availability of substitutes under
subsection (i)(4)(B), EPA identified several substitutes that are
available in place of the substances that EPA is restricting, including
some that were recently listed as acceptable, subject to use
conditions, under SNAP Rule 25 (88 FR 26382, April 28, 2023). These
include HCFO-1224yd(Z) (GWP less than 1), HCFO-1233zd(E) (GWP 4), HFO-
1234yf (GWP 1), HFO-1234ze(E) (GWP 1), HFC-32 (GWP 675), R-450A (GWP
601), R-452B (GWP 698), R-454A (GWP 237), R-454B (GWP 465), R-454C (GWP
146), R-513A (GWP 630), R-514A (GWP 3), and R-515B (GWP 287). Chillers
for comfort cooling that use lower-GWP substitutes are currently
available in both U.S. and international markets. Specifically, in the
United States, scroll, other positive displacement, and centrifugal
chillers using HCFO-1233zd(E), HFO-1234ze(E), HFC-32, R-454B, R-513A,
R-514A, and R-515B are widely available and in use.

What restrictions on the use of HFCs is EPA establishing for chillers--
industrial process refrigeration?

    EPA is restricting the use of HFCs and blends containing HFCs that
have a GWP of 700 or greater for chillers--industrial process
refrigeration as proposed and is providing additional time for
compliance based on the temperature of the fluid exiting the chiller
(i.e., the fluid sent to one or more evaporators or other cooling
equipment in the system), because the availability of substitutes for
use in equipment in this subsector is constrained based on these
conditions. As proposed, EPA is not setting restrictions at this time
for chillers where the temperature of the fluid exiting the chiller
(i.e., the supply temperature to the facility) is less than -50 [deg]C
(-58 [deg]F). For chillers where the temperature of the fluid exiting
the chiller is equal to or above -50 [deg]C (-58 [deg]F) but less than
-30 [deg]C (-22 [deg]F), EPA is restricting the use of HFCs and HFC
blends that have a GWP of 700 or greater beginning January 1, 2028
(rather than the proposed compliance date of January 1, 2025). For all
other chillers--industrial process refrigeration, EPA is restricting
the use of HFCs and HFC blends that have a GWP of 700 or greater
beginning January 1, 2026 (rather than the proposed compliance date of
January 1, 2025).
    For its consideration of the availability of substitutes under
subsection (i)(4)(B), EPA identified substitutes that are available in
place of the substances that EPA is restricting. These include R-290
(GWP 3.3), R-450A (GWP 601), R-513A (GWP 630), R-600 (GWP 4), R-717
(GWP 1), and R-744 (GWP 1). In the United States, chillers for IPR
using R-290, R-513A, R-717, and R-744 are available on the market.
    The GWP limit of 700 for chillers--industrial process refrigeration
enables the use of more refrigerant options to manage safety (in
particular, flammability and toxicity), efficiency, capacity,
temperature glide, and other performance factors.

What restrictions on the use of HFCs is EPA establishing for chillers
used in other subsectors?

    As noted above, ice rinks may use a chiller, circulating the
chilled fluid under the floor on which the ice is frozen and maintained
at the appropriate temperature. Other technologies are available, such
as a refrigeration system that circulates the refrigerant directly
through pipes to freeze the ice, then returning the evaporated
refrigerant to the compressor. Irrespective of the choice of
technology, EPA is finalizing a GWP limit of 700 and a compliance date
of January 1, 2025, for ice rinks. These restrictions are the same as
chillers for comfort cooling. See section VI.F.1.f for a discussion of
ice rinks.
    Chillers can also be used to cool data centers, ITEFs, and computer
rooms. Using a chiller for such applications could use the chilled
fluid at multiple locations, providing cooling for sections of the
facility or spot-cooling for zones where heat gain is significantly
higher than other zones. Other types of equipment are available for
such uses, including both products that are pre-charged and split
systems that are filled with refrigerant on-site. For all such
equipment, whether a chiller or not, EPA is finalizing a GWP limit of
700, consistent with several other chiller types. For those specific
applications, we are finalizing a compliance date of 2027, later than
comfort cooling chillers and IPR chillers with exiting temperatures
greater than -30 [deg]C (-22 [deg]F), but one year earlier than IPR
chillers with exiting temperatures from -30 [deg]C (-22 [deg]F) to -50
[deg]C (-58 [deg]F), See section VI.F.1.b for a discussion of data
centers, ITEFs, and computer room cooling equipment.
    Another subsector that may use a chiller is cold storage
warehouses. A chiller could be applied to circulate chiller fluid
throughout a warehouse, perhaps to keep one section at freezing
temperatures (e.g., for frozen food or ice cream) and another at above-
freezing temperatures (e.g., for dairy or meats). Like data centers,
ITEF, and computer room cooling equipment, other equipment could be
applied. For instance, an array of rooftop units could be used,
limiting the charge of each individual unit and perhaps providing more
flexibility to employ low-GWP

substitutes while complying with local building codes. All such
equipment applied in cold storage warehouses, including chillers, have
either a 300 or 150 GWP limit and a January 1, 2026, compliance date.
    Comment: Many commenters expressed support for EPA's proposal
without any suggested changes to the GWP limits or suggestions to set
GWP limits by different product capabilities and classifications.
    A few commenters suggested stricter limits at 300 or 150 and noted
that there are many viable alternatives for IPR chillers below the
proposed limit. One commenter suggested that the GWP limits for IPR
systems and chillers for IPR be based on operating temperature ranges,
like those in the current CARB and EU F-Gas Regulations. Another
commenter opposed the proposed GWP limits for chillers,\145\ stating
the current proposal will perpetuate HFCs for a longer period than is
necessary and increases the likelihood that new construction will `lock
in' HFC use in a manner that is inconsistent with the Kigali Amendment
to the Montreal Protocol phasedown and that is inconsistent with
Federal, State, and local climate goals. The commenter proposed a new
chiller GWP limit of 10 in 2027. One commenter requested clarification
of 700 GWP limit as opposed to 750 and noted that currently no SNAP-
approved alternative exists between 700 and 750.
---------------------------------------------------------------------------

    \145\ The commenter did not indicate whether the comment was
with respect to comfort cooling or industrial process refrigeration
chillers. Based on the context of the comment, which discussed
chillers with other comfort cooling technologies EPA views this as a
comment on chillers--comfort cooling.
---------------------------------------------------------------------------

    Response: EPA is finalizing a compliance date for chillers for
comfort cooling consistent with the January 1, 2025, dates proposed.
For chillers used in IPR, EPA is finalizing a compliance date of
January 1, 2026, or later for reasons explained below. For chillers
where the fluid exiting the chiller is greater than or equal to -50
[deg]C (-58 [deg]F) and below -30 [deg]C (-22 [deg]F), EPA is
finalizing January 1, 2028, as the compliance date. Consistent with the
proposed rule, EPA is not establishing restrictions at this time for
chillers--industrial process refrigeration where the temperature of the
fluid exiting the chiller is less than -50 [deg]C (-58 [deg]F). After
review of the comments received, EPA is finalizing a 700 GWP limit for
all types of comfort cooling chillers and industrial process chillers
covered in this rule. As explained above, we are also finalizing a 700
GWP limit in two other subsectors where chillers may be employed,
namely ice-skating rinks and data centers, ITEFs, and computer room
cooling equipment. Based on our review of the subsection (i)(4)
factors, EPA finds that the availability of substitutes varies for
chillers used in IPR based on the temperature of the fluid leaving the
chiller. Therefore, EPA finds it appropriate to establish a later
compliance date for lower-temperature chillers, with additional time
provided for the reasons explained below.
    The Agency disagrees with commenters asserting that EPA should
adopt a GWP limit of 300 or 150 for IPR chillers. Nor does EPA agree
that GWP limits as low as 10 are appropriate for comfort cooling
chillers. Some of the lower GWP refrigerants such as HCFO-1233zd(E),
HFO-1234ze(E), HCFO-1224yd(Z), R-717, and R-744 (with respective GWPs
of 4, 1, 1, 1, and 1, respectively) are not technologically achievable
for use in all chiller applications--either for comfort cooling or
IPR--and the use of other substitutes remains necessary to ensure a
smooth transition to lower-GWP alternatives in this subsector. Further,
in our evaluation of availability under (i)(4)(B), EPA sees higher-
pressure substitutes such as HFC-32 (GWP 675) and R-454B (GWP 465) in
comfort cooling chillers, and possibly in the future IPR chillers, as
both technologically achievable and in commercial demand, with
manufacturing already adopting or planning to adopt such solutions.
    As one commenter noted, while there are other refrigerants under
research, development, and review, EPA's SNAP program has not listed
acceptable refrigerants for the relevant subsectors with GWPs between
700 and 750. The Agency's assessment is that a 700 GWP limit is
appropriate for chillers after considering the (i)(4) factors. EPA is
prohibiting the use of regulated substances that have a GWP of 700 or
greater, in part, because there are multiple lower-GWP substitutes
available for use in chillers with a GWP less than 700. For example,
HFC-32, R-452B, and R-454B have GWPs of 675, 698, and 465,
respectively, and are acceptable for use under the SNAP program for
comfort cooling chillers.
    With respect to the compliance date for chillers--IPR, we note that
in addition to the refrigerants already available as discussed above,
EPA continues to evaluate substitutes under the SNAP program, and has
authority to do so under subsection (i)(5) of the AIM Act as well, on
an ongoing basis. In SNAP Rule 26 EPA has proposed to list as
acceptable, subject to use conditions, several additional refrigerants
for use in chillers for IPR: HFO-1234yf, HFO-1234ze(E), HFC-32, R-454B,
R-454C, R-455A, R-457A, and R-516A (with GWPs of 1, 1, 675, 465, 146,
146, 137, and 140 respectively) (88 FR 33722, May 24, 2023). Further
discussion on the intersection of SNAP listing decisions and AIM Act
subsection (i)(4) can be found in section VI.E.
    The Agency anticipates that this continuing evaluation of
additional substitutes, including for use in chillers for IPR, may help
facilitate the availability of even more options for compliance by
January 1, 2026, through January 1, 2028, depending on the IPR
chiller's characteristics.
    The Agency recognizes the time it can take for an updated UL
standard to be widely incorporated and for the updates to be applied
across industry. Many other relevant changes impacting the availability
of substitutes and facilitating transition to the use of those
substitutes generally occur after the UL standard is updated, including
evaluation of substitutes under the SNAP program, adoption of new
editions of industry safety standards into building codes, equipment
testing and certification, safety updates to manufacturing facilities,
and training of technicians. All of these are considerations for EPA's
assessment of availability of substitutes under subsection (i)(4)(B),
and EPA has accounted for the additional time needed for these updates
to occur by extending compliance dates for IPR chillers to 2026 and
2028, depending on the temperature of the fluid leaving the chiller.
The Agency is allowing for a later compliance date of January 1, 2028,
for equipment with exiting fluid temperatures lower than or equal to -
30 [deg]C (-22 [deg]F) and higher than or equal to -50 [deg]C (-58
[deg]F) because fewer refrigerants are available with a sufficiently
low boiling point to be technologically achievable, and thus, more time
may be needed to identify, test, and implement appropriate substitutes
than for equipment with higher temperature ranges.
    With respect to the compliance date for chillers--comfort cooling,
after review of the comments widely expressing support for the proposed
compliance date, EPA is finalizing a compliance date of January 1,
2025. In addition to other substitutes discussed above, EPA finalized
as acceptable more refrigerant options for use in comfort cooling
chillers through SNAP Rule 25: HFO-1234yf, R-452B, R-454A, R-454B, R-
454C and HFC-32 (with GWPs of 1, 698, 237, 465, 146, and 675,
respectively) (88 FR 26382, April 28, 2023). The Agency agrees with the
many commenters that this timeline is

sufficient considering that substitutes that meet the Agency's
restrictions are already widely available and in use in this subsector.
    Comment: Many commenters requested clarification for chillers and
IPR systems with very low temperatures that may or may not be exempt
from GWP limits under EPA's proposed rule including those for
laboratory equipment and IPR chillers. One commenter requested
clarification on refrigerated laboratory equipment that operates at -62
[deg]C (-80 [deg]F) or lower temperatures and whether industrial
process refrigeration chillers that operate at less than -50 [deg]C (-
58 [deg]F) are exempt. Another commenter suggested that EPA exempt
specialty applications for systems designed for exiting fluid
temperatures of -50 [deg]C (-58 [deg]F) or create a formal variance
application process, similar to California and Washington State
regulations. One commenter proposed an exemption for all IPR
applications with a refrigerant evaporating temperature below -45
[deg]C (-49 [deg]F). A couple of commenters requested clarification
that the exclusion in the proposed rule for equipment where the
temperature of the fluid exiting the chiller is less than -50 [deg]C (-
58 [deg]F) and how that applies in cases where the temperature may also
rise above -50 [deg]C (-58 [deg]F) while in use. The commenters also
requested an exemption in the chillers--IPR subsector to encompass all
applications in semiconductor manufacturing because chillers used in
semiconductor manufacturing are required to reach very low
temperatures, but also operate across a wide range of temperatures that
can span from below -50 [deg]C (-58 [deg]F) to as high as 5 [deg]C (41
[deg]F).
    Response: In this final rule, EPA is not setting restrictions for
HFCs or HFC blend refrigerants used in IPR equipment or chillers for
IPR with exiting fluid temperatures of -50 [deg]C (-58 [deg]F) or lower
although the Agency may in the future propose to restrict HFCs used in
such equipment. Concerning one commenter's request for either an
exception or a longer period to comply for refrigerated laboratory
equipment, to the extent that equipment used in the laboratory falls
within the chillers--IPR subsector and has exiting fluid temperatures
below -50 [deg]C (-58 [deg]F), it also would have no restrictions on
HFCs or HFC blend refrigerants under this rule. Similarly, refrigerated
laboratory equipment within the chillers--IPR subsector with exiting
fluid at temperatures -50 [deg]C (-58 [deg]F) and above but below -30
[deg]C (-22 [deg]F) would have a compliance date of January 1, 2028,
and if exiting fluid temperatures are equal to or greater than -30
[deg]C (-22 [deg]F), the compliance date would be January 1, 2026, for
new equipment to transition to alternative refrigerants. EPA did not
propose and is not finalizing a process to allow individual users to
request a variance. Further a variance process would be burdensome and
would decrease certainty that necessary transitions away from HFCs
would occur. In response to the request for clarification about
equipment where the temperature of the fluid exiting the chiller is
less than -50 [deg]C (-58 [deg]F) in some cases but also may rise above
that temperature while in use, EPA responds that if the fluid exiting
the chiller reaches -50 [deg]C or below during the normal operations of
the chiller then the equipment is not covered under this rule.
k. Residential and Light Commercial Air Conditioning and Heat Pumps
    The residential and light commercial air conditioning and heat pump
subsector includes equipment for cooling air in individual rooms,
single-family homes, and small commercial buildings. Heat pumps are
equipment types that heat, or have the option to cool and heat, air for
such locations. This subsector differs from commercial comfort air
conditioning, which uses chillers that cool water that is then used to
cool air throughout a large commercial building, such as an office
building or hotel. The residential and light commercial air
conditioning and heat pump subsector includes both self-contained and
split systems. Self-contained products include some rooftop AC units
(e.g., those where the conditioned air is ducted to supply multiple
spaces) and many types of ACs designed for use in a single room,
including packaged terminal air conditioners (PTACs), packaged terminal
heat pumps (PTHPs), some rooftop AC units, window AC units, portable
room AC units, and wall mounted self-contained ACs. Split systems
include ducted and non-ducted mini-splits (which might also be designed
for use in a single room), multi-splits and variable refrigerant flow
(VRF) systems, and ducted unitary splits. Split systems typically are
charged with refrigerant at the location of assembly and installation
(``field-assembled''). Water-source and ground-source heat pumps often
are packaged systems similar to the self-contained equipment described
in this section but could be assembled with the condenser separated
from the other components, similar to split systems. Examples of
equipment for residential and light commercial AC and heat pumps
include the following:
     Central air conditioners, also known as unitary AC or
unitary split systems. These systems include an outdoor unit with a
condenser and a compressor, refrigerant lines, an indoor unit with an
evaporator, and ducts to carry cooled air throughout a building.
Central heat pumps are similar but offer the choice to either heat or
cool the indoor space.
     Multi-split air conditioners and heat pumps. These systems
include one or more outdoor unit(s) with a condenser and a compressor
and multiple indoor units, each of which is connected to the outdoor
unit by refrigerant lines. Non-ducted multi-splits provide cooled or
heated air directly from the indoor unit rather than providing the air
through ducts.
     Mini-split air conditioners and heat pumps. These systems
include an outdoor unit with a condenser and a compressor and a single
indoor unit that is connected to the outdoor unit by refrigerant lines.
Non-ducted mini-splits provide cooled or heated air directly from the
indoor unit rather than being carried through ducts.
     Rooftop AC units. These are products that combine the
compressor, condenser, evaporator, and a fan for ventilation in a
single package and may contain additional components for filtration and
dehumidification. Most units also include dampers to control air
intake. Rooftop AC units cool or heat outside air that is then
delivered to the space directly through the ceiling or through a duct
network. Rooftop AC units are common in small commercial buildings such
as a single store in a mall with no indoor passageways between stores.
They can also be set up in an array to provide cooling or heating
throughout a larger commercial establishment such as a department store
or supermarket.
     Window air conditioners. These are self-contained products
that fit in a window with the condenser extending outside the window.
     PTACs and PTHPs. These are self-contained products that
consist of a separate, un-encased combination of heating and cooling
assemblies mounted through a wall. PTACs and PTHPs are intended for use
in a single room and do not use ducts to carry cooled air or have
external refrigerant lines. Typical applications include motel or
dormitory air conditioners.
     Portable room air conditioners. These are self-contained
products designed to be moved easily from room to room, usually having
wheels. They may contain an exhaust hose that can be

placed through a window or door to eject heat outside.
     Water-source heat pumps and ground-source heat pumps.
These systems are similar to unitary split systems except that heat is
ejected (when in cooling mode) from the condenser through a second
circuit rather than directly with outside air. The second circuit
transfers the heat to the ground, groundwater, or another body of water
such as a lake using water, or a brine if temperatures would risk
freezing. Some systems can perform heating in a similar matter with the
refrigerant circuit running in reverse; regardless, the term ``heat
pump'' is most often used.
     Variable refrigerant flow/variable refrigerant volume
systems. These are engineered DX multi-split systems incorporating the
following: a split system air conditioner or heat pump incorporating a
single refrigerant circuit that is a common piping network to two or
more indoor evaporators, each capable of independent control, or
compressor units. VRF systems contain a single module outdoor unit or
combined module outdoor units with at least one variable capacity
compressor that has three or more steps of capacity, with air or water
as the heat source. In response to comment below, we clarify that air-
source VRF systems have capacities of 65,000 BTU/h (19 kW) or more,
while water-source VRF systems can be of any capacity.
     Dehumidifiers that are integrated with the space air-
conditioning system. This includes dehumidification via a separate
bypass in the duct through which air is dehumidified, a dehumidifying
heat pipe across the indoor coil, or other types of energy recovery
devices that move sensible and/or latent heat between air streams
(e.g., between incoming air and air vented to the outside). In
addition, this subsector includes non-residential dehumidifiers, which
are used for commercial and other purposes and are typically of a
higher capacity than residential dehumidifiers.
    This subsector in its entirely is subject to the restrictions on
the use of HFCs under this rule.
    Common HFCs and blends containing HFCs used in self-contained AC
and heat pump equipment are R-410A and HFC-134a. Common HFCs and blends
containing HFCs used in mini-splits, multi-splits, unitary splits, and
VRF systems are R-410A and to a lesser extent, R-407C, with GWPs of
2,088 and 1,774, respectively. Residential split systems are commonly
shipped with a refrigerant charge that is then ``balanced'' by the
technician once the equipment is installed in its place of use. Larger
commercial sized units often are not pre-charged with refrigerant but
may contain a nitrogen ``holding charge'' for shipping.
    EPA granted petitions submitted by EIA, AHRI, CARB, and AHAM which
requested restrictions on the use of HFCs in the residential and light
commercial air conditioning and heat pump subsector. EIA's petition
refers to ``residential and non-residential''; AHRI refers to
``residential and light commercial''; and CARB, in its recently
finalized regulation, refers to the specific end-uses of ``room/wall/
window air-conditioning equipment, PTACs, PTHPs, portable air-
conditioning equipment,'' and ``other air-conditioning (new) equipment,
residential and nonresidential.'' \146\ AHAM specifically requested
restrictions on the use of HFCs for room ACs with and without electric
heat and a capacity of 25,000 BTU/hr or less and for portable ACs.\147\
For the purposes of this action, EPA considers all of these petitioned
uses within the subsector ``residential and light commercial air
conditioning and heat pumps.''
---------------------------------------------------------------------------

    \146\ California Code of Regulations, Prohibitions on Use of
Certain Hydrofluorocarbons in Stationary Refrigeration, Stationary
Air-conditioning, and Other End-uses. Available at: https://ww2.arb.ca.gov/sites/default/files/barcu/regact/2020/hfc2020/frorevised.pdf.
    \147\ The petitions can be found in the docket to this rule and
further discussion can be found in the proposed rule and in the
Federal Register notice (86 FR 57141, October 14, 2021) granting the
petitions.
---------------------------------------------------------------------------

What restrictions on the use of HFCs is EPA establishing for
residential and light commercial air conditioning and heat pumps?
    EPA is restricting the use of HFCs and blends containing HFCs, that
have a GWP of 700 or greater for all equipment types in the residential
and light commercial air-conditioning and heat pump subsector, as
proposed. EPA is prohibiting the manufacture and import of self-
contained products beginning January 1, 2025, as proposed, with
restrictions on the sale, distribution, offer for sale or distribution,
and export of products beginning January 1, 2028. For systems in this
subsector that are field-assembled, EPA is prohibiting the installation
of new systems as of January 1, 2025, except for VRF systems, which
have a compliance date of January 1, 2026.
    In our proposal to set the GWP limit for this subsector at 700, EPA
identified multiple lower-GWP substitutes currently available for use
in residential and light commercial air-conditioning and heat pump
applications. For example, R-452B, HFC-32, and R-454B have GWPs of 698,
675, and 465, respectively, and are available under EPA's (i)(4)(B)
analysis, including being listed under SNAP as acceptable, subject to
use conditions. After consideration of the comments, which were largely
supportive of the level of restriction, EPA is finalizing the GWP limit
at 700 for this subsector.
    The transition in this subsector to lower-GWP substitutes is
underway. As discussed in section VI.E.2.c, updates to the safety
standard covering these refrigerants were published on November 1,
2019, and many of the subsequent regulatory steps and industry
adaptations incorporating those updates have already occurred. SNAP
lists five lower-GWP refrigerants for use in residential and light
commercial AC and heat pumps in Rule 23 (86 FR 24444, May 6, 2021). The
International Building Code and the Residential Building Code were also
revised in 2021 to incorporate updates to the safety standards, by
allowing for the use of lower-GWP refrigerants exhibiting lower
flammability (i.e., 2L flammability classification). EPA anticipates
that States will adopt the 2021 model building codes or revise their
regulations allowing for use of several SNAP-listed lower-GWP
refrigerants that exhibit lower flammability by 2025. Several OEMs have
also indicated that they intend to switch to using A2L refrigerants
(e.g., R-454B, HFC-32) once relevant codes have been updated to allow
their use.148 149
---------------------------------------------------------------------------

    \148\ Turpin, J, R-454B Emerges as a Replacement for R-410A,
ACHR News, August 2020. Available at: https://www.achrnews.com/articles/143548-r-454b-emerges-as-a-replacement-for-r-410a.
    \149\ Turpin, J, Manufacturers Eye R-32 to Replace R-410A, ACHR
News, August 2020. Available at: https://www.achrnews.com/articles/143422-manufacturers-eye-r-32-to-replace-r-410a.
---------------------------------------------------------------------------

    EPA proposed and is finalizing a compliance date of January 1,
2026, for VRF systems. These systems are larger and more complicated
than most of the other types of equipment in this subsector. This
additional time is needed for designing, testing, and implementing the
use of substitutes in these systems.
    Comment: EPA received many comments on the proposed GWP limit for
the residential and light commercial air conditioning and heat pump
subsector.
    Many commenters expressed support for EPA's proposed GWP limit of
700 for HFCs and blends containing HFCs used in this subsector. Several
commenters requested that EPA provide more detail on the basis for
proposing a 700 GWP

limit, rather than the 750 GWP limit that petitioners requested. One
commenter in favor of a 750 GWP limit stated that proposing a lower GWP
limit than contained in the petitions does not promote stability and
fairness and it was not appropriate or necessary for EPA to do so. Some
commenters described concerns with the 700 GWP limit because of the
desire to harmonize Federal, State, and global standards, while other
commenters noted that although the GWP limit is not entirely similar to
those established by CARB, they anticipate the differences will not
create undue burden for the industry. Other commenters agreed with
EPA's reasoning in the proposed rule that there is a lack of
refrigerants with a GWP between 700 and 750. Another commenter, whose
petition also included a limit of 750 for this subsector agreed that
700 was more appropriate because the only additional refrigerant
between 700 and 750 GWP would be R-466A, which they characterized as a
step backwards due to its ozone depletion potential.
    Many commenters also expressed support for the January 1, 2025,
compliance date for this subsector. Many commenters were also
supportive of the January 1, 2026, compliance date for VRF systems;
however, a few commenters disagreed with the additional year proposed
for VRF systems due to the larger charge sizes and potentially higher
refrigerant leak rates from VRF systems, and the potential for more
releases to the atmosphere of higher-GWP refrigerants. Another
commenter suggested a GWP limit of 150 for VRF systems rather than the
proposed 700 due to the potentially higher leakage rates and volumes
from VRF systems. Another commenter suggested that EPA consider
establishing lower GWP limits with delayed compliance dates for VRF
systems (i.e., 10 or 150 GWP in 2027) to support product innovation and
achieve greater GHG emissions reduction. Several commenters asked EPA
to clarify whether VRF-type products under 65,000 BTU/hr would be
subject to the compliance dates for air-conditioning and heat pump
products (January 1, 2025) or VRF products (January 1, 2026). One
commenter stated that their smaller capacity, single-phase VRF products
could be interpreted as falling into both residential AC and VRF
category descriptions, and they suggested EPA align with the category
definitions in AHRI 1230 and AHRI 210/240 standards to clarify this
issue.
    Response: EPA is finalizing a compliance date of January 1, 2025,