What changed and why
The AIM Act, a federal law passed in 2020, directs the EPA to phase down hydrofluorocarbon (HFC) refrigerants, which trap far more heat in the atmosphere than carbon dioxide. The amount of HFCs that can be produced and imported steps down over time: a 40% cut from the baseline starting in 2024, 70% in 2029, 80% in 2034 and 85% from 2036 on.
Under the EPA's Technology Transitions rule, new home air conditioning and heat pump systems must use a refrigerant with a global warming potential (GWP) below 700 starting January 1, 2025. R-410A's GWP is about 2,088, so manufacturers moved to two lower-GWP refrigerants:
- R-454B, with a GWP of about 466. Carrier, Trane, Lennox, Rheem and York use it.
- R-32, with a GWP of about 675. Daikin, Goodman and Amana use it.
- Both are classified A2L: lower toxicity and lower flammability. R-410A is classified A1, non-flammable.
The 2026 rule change on R-410A installs
The EPA originally set January 1, 2026 as the last day to install a new split system built with R-410A components made before 2025. In a final rule published in the Federal Register on May 26, 2026, and effective July 27, 2026, the EPA removed that deadline. Split systems whose components were all made or imported before January 1, 2025 can still be installed until the existing supply runs out.
The limit on newly made equipment did not change. New systems are built for R-454B or R-32, and an R-410A system offered as new has to be stock made before 2025.
What it means for your R-410A system
If your system uses R-410A, it can be repaired and serviced like always. The EPA doesn't require anyone to stop using existing equipment, and R-410A is still available for service.
What changes over time is cost. As the cap on HFC production tightens, R-410A is expected to get more expensive. Two things follow from that:
- Fix leaks instead of topping off. An air conditioner doesn't use up refrigerant, so a low charge means a leak somewhere, and adding refrigerant year after year gets pricier as supply shrinks.
- Weigh big repairs on older systems. If your system is near the end of its life and needs a major refrigerant repair, ask for a repair price and a replacement price side by side.
- Repairs that don't involve refrigerant, like capacitors, motors, igniters or controls, aren't affected by the change.
What it means when you replace
A new system will use R-454B or R-32, and that brings a few changes you should know about before you compare quotes:
- You can't mix refrigerants. R-454B isn't a drop-in replacement for R-410A, and the two can't be swapped or combined in one system.
- The indoor coil changes too. The outdoor unit and indoor coil have to be matched and rated for the same refrigerant, so replacing an R-410A outdoor unit with an A2L unit also means replacing the indoor coil, and on air handler systems usually the whole air handler.
- Your line set may be reusable. The copper lines between the indoor and outdoor units can often be reused if they're the right size and in good condition, after being flushed, pressure-tested and evacuated. Damaged or undersized lines should be replaced.
- There may be a leak sensor. Under the UL 60335-2-40 safety standard, many A2L systems, generally those holding more than about 4 pounds of refrigerant, include a refrigerant sensor. If it detects a leak, it shuts off the compressor and turns on the indoor blower to spread the refrigerant out.
Is A2L refrigerant safe?
Yes, when it's installed the way the manufacturer specifies. A2L refrigerants are rated mildly flammable: they're hard to ignite and burn slowly, and the equipment is designed around that with charge limits, clearances and leak sensors. Installers have to follow the manufacturer's instructions for all three.
How HVAC Doctor handles the change
We work on both. We'll repair an R-410A system and tell you honestly whether the repair is worth it. If you're replacing, we size the new system with a Manual J load calculation, check whether your line set can be reused, match the indoor and outdoor equipment, and set up the leak sensor where the system has one.
If another company told you that you need a new system because of the refrigerant change, get a second opinion before you sign. Our diagnostic is $39, credited in full to any repair you approve, and you get a firm price before any work starts.
Need a hand with this?
Call or text and talk to Ahmad or Ammar, the owners. The diagnostic is $39, credited to your repair, and you get a firm price before any work starts. Open 24/7 with no overtime fees.
Common questions
Do I have to replace my R-410A system?
No. The EPA doesn't require anyone to replace working R-410A equipment. It can still be repaired and serviced, and R-410A is still available. The refrigerant rules apply to new equipment.
Can R-454B be added to my R-410A system?
No. The two refrigerants can't be mixed or substituted. An R-410A system stays on R-410A, and an R-454B system has to use R-454B.
Is R-454B safe to have in my home?
Yes, when it's installed correctly. It's classified A2L, meaning lower toxicity and lower flammability, and many systems include a leak sensor that shuts off the compressor and runs the indoor blower if refrigerant is detected.
Can new R-410A systems still be installed in 2026?
In some cases, yes. Under an EPA rule that took effect July 27, 2026, split systems made entirely from components manufactured or imported before 2025 can still be installed until that supply runs out. Newly manufactured systems must use a lower-GWP refrigerant such as R-454B or R-32.
What's the difference between R-454B and R-32?
Both are A2L refrigerants that replaced R-410A in new equipment. R-454B has a GWP of about 466 and R-32 about 675, and they can't be swapped for each other. For a homeowner, correct sizing and installation matter more than which refrigerant the brand chose.