R-410A, R-454B and what the refrigerant change means for your Miami AC

What changed in 2025

Under the AIM Act, EPA's Technology Transitions rule set a global warming potential limit of 700 for refrigerant in new residential and light commercial air conditioners and heat pumps manufactured or imported from January 1, 2025. R-410A, with a global warming potential of about 2,088, is far over that limit, so manufacturers moved to R-454B, rated about 466, and R-32, about 675. Most residential split systems now ship with one of those two.

What the 2026 EPA rule did

The original rule also set January 1, 2026 as the last day to install split systems built with R-410A before 2025. In May 2026 EPA finalized a change, effective July 27, 2026, that removed that installation deadline for residential and light commercial equipment whose components were all made or imported before 2025. In practice, leftover R-410A inventory can still be installed until it runs out, but no new R-410A residential equipment is being made.

If your system runs on R-410A

Nothing forces you to replace it. R-410A systems can be repaired and recharged for as long as they last, and refrigerant remains available for service. What changes over time is the price: the AIM Act keeps cutting the supply of new HFC refrigerants on a fixed schedule, so R-410A for leak repairs is likely to keep getting more expensive.

That makes leak repair more important than ever. Topping off a leaking system every summer gets expensive fast, and finding and fixing the leak is the better spend.

If you are replacing a system

A new system will most likely use R-454B or R-32. Both are classed A2L, meaning mildly flammable, so the equipment carries leak detection and other safety features and installers follow updated procedures. A new outdoor unit cannot simply be paired with an old R-410A indoor coil; the indoor and outdoor sections are replaced as a matched system.

Your existing line set may be reusable if it is the right size and in good condition, which the installer checks against the manufacturer's requirements. In Miami a replacement also needs a mechanical permit and has to meet Florida's Southeast-region efficiency minimum.

Should you buy leftover R-410A equipment?

It can be cheaper up front, and it is legal under the 2026 rule. The trade-off is that you are buying into a refrigerant whose supply keeps shrinking, so future leak repairs will cost more. For a system you expect to keep twelve or fifteen years, most homeowners are better served by R-454B or R-32 equipment, unless the price gap is large and the installed system is a properly matched one.