AIM Act refrigerant rules for HVAC/R techs

The phasedown: how much HFC can be made

The AIM Act cap is on total production and consumption of HFCs in the US, counted in exchange-value-weighted tons, not on any one refrigerant. Under 40 CFR 84.7:

The phasedown began in 2022, not 2025. The 2025 date is the Technology Transitions equipment restriction, which is a separate program. The next step down is January 1, 2029.

HFOs such as R-1234yf and R-1234ze(E) are not regulated substances under Part 84.

Exchange values and GWP

EPA’s exchange values in Part 84 Appendix A are the IPCC AR4 100-year GWPs. Common values on that basis:

For R-454B, the commonly published 466 includes a value of 4 for R-1234yf. The values EPA uses in 40 CFR 84.64 for the Technology Transitions limits give 465. Either way it is under 700. The refrigerant GWP chart lists the rest.

Technology Transitions: GWP limits on new equipment

Technology Transitions (40 CFR 84.54, from the October 24, 2023 rule, 88 FR 73098) restricts the GWP of refrigerant in new products and new installed systems. 91 FR 31284, published May 26, 2026 and effective July 27, 2026, changed several of the limits and dates. The installation limits most techs deal with, as the eCFR reads now:

Exceptions that matter on the job

• Residential and light commercial split systems. New systems over the limit “may continue to be installed where all specified components of that system are manufactured or imported prior to January 1, 2025.” The 2026 rule removed the installation deadline for that equipment. Equipment built in Canada or Mexico before 2025 but imported after that date may not be installed as a new system.
• Condensing unit replacements. The 2026 preamble states that “the replacement of a condensing unit on an existing system is allowed and is not considered the installation of a new system.”
• Self-contained products. Window units, PTACs and other self-contained residential and light commercial AC/HP products over the limit cannot be manufactured or imported from January 1, 2025 (84.54(a)(1)). Under 84.54(b), their sale and distribution is prohibited three years after that date, so from January 1, 2028.
• VRF. VRF systems over the limit may be installed until January 1, 2027 if all specified components were made or imported before January 1, 2026, and until January 1, 2028 with an approved building permit issued before October 5, 2023.
• Supermarkets. Under 84.54(e)(2) as amended, increasing an existing supermarket system’s capacity by up to 15% is not treated as installing a new system.

What counts as installing a new system

Under 84.54(e), each of these counts as an installation once the system is charged to full charge: assembling a system for the first time from used or new components; increasing the cooling capacity of an existing system (beyond 15% for a supermarket system); or replacing 75% or more of evaporators (by number) and 100% of compressor racks, condensers and connected evaporator loads.

Leak repair (Emissions Reduction and Reclamation rule)

The ER&R rule, 89 FR 82682 (October 11, 2024), added HFC leak repair at 40 CFR 84.106. From January 1, 2026 it applies to appliances with a full charge of 15 lb or more of an HFC, or of a substitute with a GWP above 53. It does not apply to the residential and light commercial AC and heat pump subsector, or to appliances that contain only an ozone-depleting refrigerant such as R-22.

The leak rate thresholds that trigger repair are:

• 20% for commercial refrigeration
• 30% for industrial process refrigeration
• 10% for comfort cooling, refrigerated transport and other covered appliances

Anyone adding or removing refrigerant must give the owner or operator documentation, and the owner calculates the leak rate each time refrigerant is added. Leaks over the threshold must be found by a certified technician and repaired within 30 days (120 days if an industrial process shutdown is needed). Each repair needs an initial and a follow-up verification test.

Reclaimed refrigerant

Under 40 CFR 84.112:

• From January 1, 2026: refrigerant may not be sold or reported as reclaimed if its HFC content is more than 15% virgin by weight. Reclaimers must label containers with the statement that the contents do not exceed that 15% limit.
• From January 1, 2029: servicing and repair must use reclaimed refrigerant only in supermarket systems, refrigerated transport and automatic commercial ice makers.

Residential AC is not on the 2029 list. A residential R-410A system can be serviced with virgin or reclaimed R-410A.

Disposable cylinders

Under 40 CFR 84.116, from January 1, 2028, anyone who finishes with a disposable cylinder that held an HFC and was used for servicing, repair or installation must send it for heel removal. It can go to a certified reclaimer, a final processor (such as a landfill operator or scrap metal recycler) able to remove the heel, or a refrigerant supplier able to do so.

The alternative is for a certified technician to evacuate the heel to 15 in Hg vacuum and sign a statement with their name, address and the date. That statement goes with the cylinder to the final processor, who keeps it for three years. Small cans of 2 lb or less that qualify for the 82.154(c)(1)(ix) exemption are not covered.

What this means for a service call

• Repairing and recharging an existing R-410A, R-404A or R-134a system remains legal. See the R-410A phase-out.
• Supply of HFC refrigerant is set by the cap, which drops to 30% of baseline in 2029.
• New residential systems are mostly R-454B or R-32 (A2L). See the A2L refrigerants guide.
• For commercial refrigeration, check the 1,400 and 700 interim limits and the 2032 limits before quoting a new system; see R-404A replacement.
• Venting, recovery and Section 608 certification still come from 40 CFR 82 subpart F, which has covered HFC substitutes since January 1, 2018.