Most mini splits sold in recent years use R-410A refrigerant, but the industry is actively shifting to lower-impact alternatives. Starting in 2025, new U.S. regulations prohibit manufacturing residential air conditioning equipment with R-410A, making R-32 and R-454B the two refrigerants you’ll see in newly installed mini splits going forward.
R-410A: The Current Standard
R-410A has been the dominant refrigerant in mini splits and other residential cooling systems since 2010, when the EPA banned production of new equipment using R-22 (commonly called Freon). If your mini split was installed in the last 15 years, it almost certainly runs on R-410A. The refrigerant works well, transfers heat efficiently, and operates at higher pressures than its predecessor, which is partly why mini split compressors became smaller and more reliable over that period.
The problem with R-410A is its global warming potential (GWP) of 2,088, meaning that one pound released into the atmosphere traps as much heat as 2,088 pounds of carbon dioxide. That number put it squarely in the crosshairs of the EPA’s hydrofluorocarbon phasedown. As of January 1, 2025, manufacturers can no longer produce or import residential air conditioning products that use R-410A. After January 1, 2026, any newly installed split system must use a refrigerant with a GWP below 700.
If you already own an R-410A mini split, you don’t need to replace it. The regulations target new equipment, not existing installations. R-410A will remain available for servicing and topping off existing systems for years to come.
R-32: The Leading Replacement
R-32 is the most common next-generation refrigerant in mini splits worldwide. Its GWP of 675 sits just below the new EPA threshold of 700, representing roughly a two-thirds reduction compared to R-410A. Several major manufacturers, particularly those based in Asia where mini splits dominate the market, have already adopted R-32 across their product lines.
Performance testing shows R-32 isn’t just an environmental upgrade. In lab comparisons, R-32 systems delivered up to 10% more cooling capacity and 9% better energy efficiency than identical R-410A systems. Heating performance showed an even bigger gap, with R-32 producing a 14% higher coefficient of performance in heating mode. That means a mini split running R-32 can do the same work while drawing less electricity, which translates to lower utility bills over the life of the unit.
R-32 also requires a smaller charge volume per system. Less refrigerant per unit means lower manufacturing costs and a smaller potential environmental impact if a leak occurs.
R-454B: The Other Contender
R-454B is a blend of R-32 and a compound called R-1234yf. It has a GWP of 467, even lower than pure R-32. Trane began phasing R-454B into its residential heat pumps in 2024, and several other North American manufacturers are following suit. You’ll increasingly see R-454B listed on spec sheets for mini splits sold in the U.S. market.
The choice between R-32 and R-454B often comes down to the manufacturer. Brands with strong roots in the Asian market tend to favor R-32, while companies focused on the North American market have leaned toward R-454B. Both meet the EPA’s GWP requirements, and from a homeowner’s perspective, performance differences between the two are minor.
Safety Ratings for Newer Refrigerants
Both R-32 and R-454B carry an A2L safety classification. The “A” means low toxicity. The “2L” means mildly flammable, specifically that they can burn but do so very slowly. R-410A, by contrast, is classified A1 (not flammable at all). This difference sounds alarming, but the practical risk is extremely low. A2L refrigerants require an ignition source and a concentration well above what a typical leak would produce in a room. Building codes have been updated to account for A2L refrigerants, and modern mini splits include leak detection sensors as an added safeguard.
You don’t need to handle refrigerant yourself regardless of the type. Charging, recovering, and servicing refrigerant requires EPA Section 608 certification and specialized equipment.
How to Check What Your Mini Split Uses
Every mini split has a nameplate, a metal plate or heavy-duty sticker that lists the refrigerant type and factory charge amount. On the outdoor compressor unit, look near the service valves where the copper refrigerant lines enter the cabinet. It’s typically on the right-hand side panel. The label will say “Refrigerant” or “REFRIG” followed by a designation like R-410A or R-32. Indoor units sometimes have a second label on the underside or side of the wall-mounted head.
If your unit is old enough to use R-22, the nameplate will confirm it. Since R-22 production and import have been illegal in the U.S. since January 2020, servicing those systems has become expensive. Replacement is usually more cost-effective than paying premium prices for dwindling R-22 supplies.
What This Means If You’re Buying
If you’re shopping for a new mini split in 2025 or later, your unit will come with either R-32 or R-454B. Both are more efficient and far less harmful to the climate than R-410A. The specific refrigerant will depend on the brand and model you choose, not on a decision you need to make separately. When comparing units, pay more attention to the SEER2 efficiency rating and heating capacity than to which of the two new refrigerants it uses. Both are solid options that meet current regulations and perform as well as, or better than, the R-410A systems they replace.