R-410A, R-454B and the refrigerant change: what it means for you

What changed, and when?

Under the AIM Act, the EPA restricts the refrigerants that new equipment may use. For residential and light commercial air conditioners and heat pumps, the limit is a global warming potential (GWP) of 700, and it has applied to equipment manufactured or imported since January 1, 2025.

R-410A, the refrigerant in most systems installed over the last fifteen years, has a GWP of roughly 2,000, so new equipment moved to alternatives. The two you will see most are R-454B and R-32. For split systems, the EPA sets no installation deadline where every component was manufactured or imported before January 1, 2025 — so R-410A equipment already in the supply chain can still be installed.

Can I keep my R-410A system?

Yes. Nothing requires you to replace a working system, and R-410A systems are repaired the same way they always were. The refrigerant itself is still produced, though under a national phasedown of HFCs, which tends to push its price up over time.

Where the change bites is a major failure on an older R-410A system — a compressor, or a leaking coil. That repair has to be weighed against a replacement that will use a different refrigerant, which is the decision the repair-or-replace guide walks through.

What are A2L refrigerants, and are they safe?

R-454B and R-32 are classed A2L: lower toxicity, and mildly flammable — much harder to ignite than a flammable gas, but not inert the way R-410A is. Equipment designed for them includes safeguards appropriate to the refrigerant, and building codes govern how it is installed.

For a homeowner the practical rule is the same as it always was: refrigerant work belongs to a certified technician, and the equipment must be installed to the manufacturer's instructions.

Can old and new equipment be mixed?

No. Refrigerants cannot be mixed in a system, and the indoor coil and outdoor unit must be designed and listed for the same one. That rules out pairing a new R-454B outdoor unit with an existing R-410A coil.

The copper refrigerant lines between them are different: they can sometimes be reused, depending on their size, condition and the manufacturer's instructions. That is a question to ask at the survey rather than an assumption to make.

What about systems that still use R-22?

No new R-22 has been made in or imported into the United States since January 1, 2020. Reclaimed R-22 is still available to service existing systems, and the EPA does not require anyone to replace one. But a significant leak on an R-22 system is usually the point at which replacement makes more sense than repair.

What should you ask a contractor?

These questions have straightforward answers from anyone doing the work properly:

• Which refrigerant does the proposed system use?
• Are the indoor and outdoor sections a matched, listed pair for it?
• Can the existing refrigerant lines be reused, and how was that checked?
• What does the manufacturer require to register the warranty?