Refrigerant Transition Guide
R-410A Phase-Out and the A2L Transition
Why R-410A is leaving new equipment, what replaces it, the dates that matter, and what the change means for the systems you install and service.
The key dates
| Date | What happens |
|---|---|
| December 27, 2020 | The AIM Act is enacted, directing EPA to phase down HFCs 85 percent by 2036. |
| January 1, 2025 | A new split system (other than VRF) at or above 700 GWP may be installed only if all of its specified components (condensing unit, condenser, compressor, evaporator unit and evaporator, as 40 CFR 84.52 defines them) were made or imported before January 1, 2025 (40 CFR 84.54(c)(1)), and self-contained units at that GWP may no longer be manufactured or imported (84.54(a)(1)). New systems built from new parts use R-454B or R-32. |
| January 1, 2026 (removed) | The 2023 rule's original cutoff to install leftover R-410A systems whose components were all made before January 1, 2025. EPA later removed this installation deadline for the residential and light-commercial subsector: a final rule (91 FR 31284, Docket EPA-HQ-OAR-2025-0005) published May 26, 2026 lets that equipment keep being installed. |
| July 27, 2026 | The final rule removing the R-410A install deadline takes effect. Variable refrigerant flow (VRF) systems were not given the same relief, so their own subsector deadline still applies. |
Sources: EPA Technology Transitions HFC restrictions by sector and the AIM Act phasedown FAQ (epa.gov); the install-deadline removal is the EPA final rule 91 FR 31284(Federal Register, May 26, 2026, Docket EPA-HQ-OAR-2025-0005). Accessed July 2026.
The lower-GWP replacements
The 700 GWP limit is what decides which refrigerants stay in new equipment. R-410A sits well above it; the A2L replacements sit below it.
| Refrigerant | GWP | Under 700 limit? | Role in new equipment |
|---|---|---|---|
| R-410A | 2,088 | No, restricted | The A1 (nonflammable) blend being phased out of new equipment for its high GWP. Existing R-410A systems keep running and are still serviced with R-410A. |
| R-454B | 465 | Yes | The A2L leading in new ducted systems (Carrier Puron Advance, Trane, York). |
| R-32 | 675 | Yes | The A2L leading in new ductless mini-splits (Daikin, Goodman). |
GWP values are read from EPA's published table and the in/out verdict is derived from the 700 limit, re-checked on every build. For the full property comparison (safety class, LFL, pressures), see the A2L refrigerant properties page.
The AIM Act HFC phasedown
The equipment rule sits on top of a supply phasedown. The AIM Act caps how much HFC refrigerant (by weight and climate impact) can be produced or imported each year, stepping down to 15 percent of the historic baseline. This is why legacy refrigerants like R-410A are expected to get scarcer and pricier over time, even though servicing existing systems remains legal.
| Years | HFC production and consumption allowed (% of baseline) |
|---|---|
| 2020-2023 | 90% |
| 2024-2028 | 60% |
| 2029-2033 | 30% |
| 2034-2035 | 20% |
| 2036 and after | 15% |
What it means on the job
- Existing R-410A systems are fine. Keep repairing and recharging them with R-410A. No federal rule requires an early changeout, though state or local programs may differ.
- New systems are A2L. R-454B and R-32 are mildly flammable, so new equipment adds leak detection, reduced charge limits tied to room size, and A2L-rated components per UL 60335-2-40 and ASHRAE 15.2.
- A2L is not a drop-in. You cannot put R-454B or R-32 into an R-410A system. The equipment has to be designed and listed for the A2L refrigerant.
- Line sets and charge need a second look. Reusing an old R-410A line set for an A2L changeout has its own reuse and flush rules, and the charge has a room-size ceiling.
Frequently Asked Questions
When is R-410A being phased out?
Under EPA's Technology Transitions rule (AIM Act), a new split air conditioner or heat pump system (other than variable refrigerant flow) using a refrigerant at 700 GWP or above may be installed from January 1, 2025 only if all of its specified components (condensing unit, condenser, compressor, evaporator unit and evaporator, as 40 CFR 84.52 defines them) were made or imported before January 1, 2025, and self-contained units (packaged, window and through-the-wall) using such a refrigerant may not be manufactured or imported from January 1, 2025 (40 CFR 84.54(a)(1) and (c)(1); components are exempt from the manufacture ban under 84.56(b)). R-410A (GWP 2,088) is above that limit, so new systems built from new parts use R-454B or R-32. Existing R-410A systems keep running and are still serviced with R-410A.
Is R-410A banned?
No. The rule restricts R-410A in NEW residential and light-commercial AC and heat pump systems: a new split air conditioner or heat pump system (other than variable refrigerant flow) using a refrigerant at 700 GWP or above may be installed from January 1, 2025 only if all of its specified components (condensing unit, condenser, compressor, evaporator unit and evaporator, as 40 CFR 84.52 defines them) were made or imported before January 1, 2025, and self-contained units (packaged, window and through-the-wall) using such a refrigerant may not be manufactured or imported from January 1, 2025. It does not ban owning, servicing, or topping off an existing R-410A system, replacement components are exempt, and R-410A remains available for service.
Can I still buy R-410A?
Yes. R-410A is still produced and sold for servicing the large installed base of existing systems. What changed is which new systems may be installed with it: a new split system from 2025 uses a lower-GWP A2L refrigerant unless all of its specified components were made or imported before then. R-410A is expected to get more expensive over time as the AIM Act phases down HFC supply (85 percent below baseline by 2036).
Can R-410A equipment still be installed?
Yes, for pre-2025 stock. The 2023 rule originally set an install cutoff of January 1, 2026 for systems whose components were all made or imported before January 1, 2025, but EPA removed that deadline for the residential and light-commercial subsector in a final rule (91 FR 31284, Docket EPA-HQ-OAR-2025-0005) published May 26, 2026 and effective July 27, 2026. So that R-410A equipment can continue to be installed. Variable refrigerant flow systems were not given the same relief.
Why is R-410A being phased out?
R-410A has a GWP of 2,088, well above the 700 limit EPA set for new residential and light-commercial AC and heat pumps under the Technology Transitions rule. The rule carries out the AIM Act's goal of cutting HFC use, so new systems installed from 2025 use lower-GWP A2L refrigerants instead, apart from split systems built entirely from components made or imported before then.
What is the AIM Act?
The American Innovation and Manufacturing Act of 2020, enacted December 27, 2020, directs EPA to phase down production and consumption of HFCs by 85 percent from a historic baseline by 2036. The Technology Transitions rule that restricts R-410A in new AC equipment is one part of carrying that out.
Do I have to replace my R-410A system?
No federal rule requires replacing a working R-410A system. It can be repaired and recharged with R-410A for its service life. The rule bounds installing NEW systems and manufacturing new self-contained units, not equipment already in service. Some state or local programs may have their own rules, so check locally.
Related Tools & References
A2L Refrigerant Properties
GWP, ASHRAE safety class, and LFL for R-454B, R-32, R-410A, and the A2L transition set.
A2L Charge Limit Calculator
Maximum R-454B or R-32 charge for a room, per UL 60335-2-40 and ASHRAE 15.2.
A2L Line Set Calculator
Reuse, flush, or replace verdict and sizing when converting an R-410A set to R-454B or R-32.
Superheat & Subcooling Calculator
Charge diagnosis for R-454B, R-32, R-410A, and 8 more refrigerants.
Charging an A2L system? Check the room charge limit.
A2L refrigerants come with a charge ceiling tied to room size. The charge limit calculator runs the UL 60335-2-40 and ASHRAE 15.2 math for R-454B, R-32, and more.
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