For stationary air conditioning and heat pumps, the rule sets a 700 GWP limit for most new comfort cooling equipment, effective January 1, 2025. As a result, the production of most systems that utilized R-410A was discontinued as of that date. On the commercial refrigeration side, new retail food stand-alone equipment transitioned to a 150 GWP limit on January 1, 2025, while new remote condensing units require GWP limits of 150 to 300 GWP in 2026. Similar GWP limits on supermarket parallel rack systems will follow in 2027. 

Reconsideration? 

So, what does it mean that the EPA is reconsidering the Technology Transitions (TT) rule? Right now, it’s unclear whether the agency will make any changes. While EPA is accepting public comments on the rule until August 1, 2025, the agency has not altered any GWP limits or implementation timelines, and the refrigerant transition under the AIM Act remains on track. 

Some hoped that reconsideration would mean a return to the use of R-410A in comfort cooling equipment, but that is highly unlikely. HVAC manufacturers have already transitioned their comfort cooling systems to A2L refrigerants like R-32 and R-454B, and a return to R-410A would be very expensive. 

As for commercial refrigeration, reconsideration could potentially affect the timeline for equipment used in supermarkets and convenience stores, since some GWP compliance deadlines in the final rule are still months or years away. Several trade groups, including FMI – The Food Industry Association, filed a lawsuit challenging the rule. They argue that the timeline for supermarket refrigeration equipment violates the AIM Act and is arbitrary and capricious, meaning the EPA did not adequately consider key factors when setting the deadlines. A decision in the case has not yet been reached, said Stephanie Harris, chief regulatory officer and general counsel at FMI. 

“The litigation is still pending with the case being held in abeyance while EPA reconsiders the TT Rule,” she said. “EPA announced its intention to reconsider certain aspects of the rule as part of the agency’s deregulatory efforts. We understand that EPA is currently working on a proposed rule, which will be open for comment in the coming months.” 

EPA recently released a publication, entitled, “American Innovation and Manufacturing Act: Technology Transitions Provisions: Powering the Great American Comeback Fact Sheet,” which does not provide much additional clarity, but it did give two reasons for reconsidering the TT rule: 

• Concerns related to the time provided for compliance and the scope of applicability; and  

• To allow time for companies to successfully transition to new solutions from U.S. chemical and manufacturing companies for the affected commercial and industrial refrigeration uses. 

The fact sheet added that the average cost of compliance for the industries that EPA intends to reconsider is $30.87 million per year for the first five years. The agency added that, “reconsideration could provide additional time and increased flexibility for those industries.” 

Petition 

Another group urging the reconsideration of the TT rule is the Coalition for the Use of Safe and Efficient Refrigerants Inc. (CUSER), which represents the cold storage warehouse sector. According to their recent petition submitted to EPA, their members “design, build and/or use industrial packaged synthetic refrigerant systems utilizing HFCs that meet the 700 GWP threshold established by EPA for most industrial/commercial-scale sectors.” The petition contends that, “our current designs generally cannot meet the lower 150 GWP threshold that EPA imposed on the cold storage sector in the 2023 final rule.” 

As such, the coalition is asking EPA to impose a limit of 700 GWP for refrigerants used in the cold storage warehouse sector, rather than the current caps of 150 GWP and 300 GWP, which are scheduled to take effect next year. The higher GWP limit would specifically allow the use of R-513A, which has a GWP of 631. According to CUSER, “The supply chain has successfully developed to support R-513A refrigerant. However, the substitutes identified by EPA in its Technology Transition Rule for the cold sector remain largely unavailable and cost-prohibitive despite EPA’s predictions that substitutes would become commercially available.” 

In the petition, the coalition requested that “EPA act quickly on this petition by initiating a rulemaking to promulgate a final rule as soon as possible but no later than mid-2025 with the goal that the 700 GWP restriction for cold storage should become effective as soon as possible but no later than January 1, 2026.” 

In response to the CUSER petition, the International Institute of All-Natural Refrigeration (IIAR) — a non-profit organization representing members across the industrial and commercial refrigeration sector —  submitted a letter arguing that raising the GWP limit from 150 to 700 “serves the narrow interests of a few stakeholders, disregards the facts, and ignores current technological realities.” 

The IIAR letter went on to say that the AIM Act’s HFC reduction timeline is achievable, thanks to the cold storage industry’s long-standing use of natural refrigerants such as ammonia, CO₂, air, water, and hydrocarbons. “Current natural refrigeration systems can easily meet the phase-down schedule proposed by EPA, particularly for cold storage applications where they are already in active, majority, and expanding use. The cold storage sector does not require a relaxation of the 150 GWP limit. Natural refrigerants are already in widespread use, supported by decades of experience and infrastructure.” 

The letter concluded that, “Current technology can enable end users to install systems that are safer and more efficient than higher GWP synthetic refrigerants. We urge the EPA to reject the CUSER petition and uphold the 150 GWP limit for new cold storage systems.” 

The bottom line is that it is still unclear how the EPA may reconsider the TT rule. For now, this adds a layer of uncertainty, but it doesn’t change the current course of the refrigerant transition. GWP limits and implementation timelines remain in place, and the phasedown outlined in the AIM Act continues as planned. Until the EPA provides further guidance, the HVACR industry will have to take a wait-and-see approach.