R-454B and the refrigerant change: what it means for your AC

The short answer

New central air conditioners and heat pumps now use refrigerants such as R-454B or R-32 instead of R-410A. If you have an R-410A system that works, nothing about this change forces you to replace it, and it can still be repaired. The change matters when you replace a system: the new equipment, the way it's installed and the way it's serviced are all built around the new refrigerants.

What changed in 2025

Under the federal AIM Act, EPA restricts the refrigerants allowed in new equipment based on their global warming potential (GWP). Since January 1, 2025, new residential and light-commercial air conditioning and heat-pump systems may not be installed with a refrigerant whose GWP is 700 or higher. R-410A, with a GWP of 2,090 by EPA's listing, is above that limit. R-454B (470) and R-32 (675) are below it.

The industry moved quickly. In its 2026 rulemaking, EPA cited industry figures showing that equipment using these new refrigerants made up about 90% of the market by the end of the 2025 cooling season. EPA also noted that R-454B was briefly hard to get in some regions in 2025 while the supply chain caught up.

Can my R-410A system still be repaired?

Yes. EPA states plainly that components used to repair existing systems are not subject to these restrictions, and it chose not to restrict repair of R-410A systems. A homeowner whose outdoor unit fails can choose to replace that unit rather than buy a whole new system, according to EPA's 2026 rule.

What does change over time is supply. The AIM Act steps down U.S. production and consumption of HFC refrigerants like R-410A: to 60% of the baseline from 2024 through 2028, 30% from 2029, and lower after that. EPA expects R-410A to remain available to service existing equipment, following the path R-22 took, where systems kept running for many years after production stopped.

That doesn't mean a leaking R-410A system should simply be topped off. A system that's low on refrigerant has a leak, and finding it is the repair.

What about systems made before 2025?

When the rule first took effect, there was a deadline for installing R-410A systems that had been made before 2025. A rule published in May 2026, in effect since July 27, 2026, removed that deadline, but only for systems where all of the main components were made or imported before January 1, 2025. EPA's list of those components is condensing units, condensers, compressors, evaporator units and evaporators.

Two practical points follow. First, making or importing new R-410A equipment is still banned, so that stock is finite and shrinking. Second, the rules treat some kinds of work on an existing system as installing a new system, which brings the new refrigerant limit into play. Increasing the system's cooling capacity and replacing most of its main components are two examples. Whether a particular change-out counts is something your contractor should confirm against the rule before you decide.

What "A2L" means and why it matters

ASHRAE's safety classification gives R-454B and R-32 the rating A2L: lower toxicity ("A") and lower flammability ("2L"). EPA uses the term "lower flammability." In plain terms, these refrigerants can burn under specific conditions, but the 2L class is limited to refrigerants that burn very slowly and release relatively little heat when they do.

Because of that, EPA allows them in home air conditioners only under conditions that shape the equipment itself:

• The equipment must meet the UL 60335-2-40 safety standard and carry warning labels.
• Service ports and field connections carry red markings so technicians can tell at a glance.
• Some equipment includes a built-in refrigerant detector. In most cases a detection triggers the blower to run and mix the air, rather than an alarm.
• The units carry a label saying that devices which could be ignition sources shouldn't be installed in the ductwork unless they're listed for use with that equipment. That's worth knowing before adding an in-duct accessory such as a UV light or an air cleaner to a new system.

EPA's guidance for servicing A2L equipment calls for technicians trained in handling these refrigerants, with recovery equipment and tools suited to them. As with any refrigerant work, technicians need EPA Section 608 certification.

Can my old system be converted to R-454B?

No. EPA lists R-454B and R-32 for home air conditioning only in new equipment designed specifically for that refrigerant. An R-410A or R-22 system can't be "retrofitted" to use one of them.

What can sometimes carry over is the copper line set between the indoor and outdoor units: EPA concluded that existing tubing can be inspected and reused if it's suitable. Whether yours is suitable depends on its size, condition and route, and the new equipment's installation instructions.

Why the indoor and outdoor units must match

A new outdoor unit using R-454B needs an indoor coil designed for the same refrigerant. Beyond the refrigerant rules, Florida's energy code requires matched systems on replacements, and efficiency ratings belong to a tested indoor-outdoor combination. In practice, a replacement under the new rules is a matched indoor and outdoor system, not an outdoor unit alone. See central air conditioners and heat pumps.

If you have an R-22 system

U.S. production and import of R-22 ended on January 1, 2020. EPA's guidance to homeowners is that you may continue using R-22 in your existing system for as long as necessary; service relies on recovered and reclaimed R-22 and refrigerant made before 2020. In its 2026 rule, EPA cited an estimate that more than 15% of installed home AC systems still use it.

EPA also warns against "R-22a," which is not an acceptable replacement: it's a blend of flammable hydrocarbons such as propane and butane.

If an R-22 system develops a refrigerant leak, that's usually a good time to price a replacement alongside the repair before you decide. The repair-or-replace guide walks through the decision.

What to ask before you replace

• Which refrigerant does the new system use, and is the indoor coil matched to it?
• Will the existing line set be reused, and has it been checked?
• Does the equipment include a refrigerant detector, and what does it do?