For most homeowners buying a new air conditioning system in 2025 or later, R-32 and R-454B are the two refrigerants worth comparing. Both replace the outgoing R-410A, both carry the same mild-flammability safety rating (A2L), and both cut global warming impact by roughly 70% or more compared to R-410A. R-32 edges ahead on raw cooling performance and efficiency, while R-454B has a slightly lower environmental footprint on paper. Which one you end up with largely depends on which brand of equipment you choose.
Why R-410A Is on Its Way Out
As of January 1, 2025, new residential air conditioners and heat pumps in the United States can no longer use a refrigerant with a global warming potential (GWP) of 700 or higher. R-410A, the standard for the past two decades, has a GWP of roughly 2,088, nearly three times over that limit. Equipment manufactured or imported before that date can still be installed to sell through remaining inventory, but no new R-410A systems are being produced. The EPA plans to reduce overall HFC production by 85% by 2036, which means R-410A will only get more expensive for anyone still topping off an older system. Current prices already sit between $40 and $75 per pound, and that number will keep climbing as supply tightens.
R-32 vs. R-454B: The Two Leading Replacements
R-32 has a GWP of 675, comfortably under the new 700 threshold. R-454B, a blend of R-32 and a lower-GWP compound called R-1234yf, comes in at about 466. On paper, R-454B looks greener, but the full picture is more nuanced.
When you account for the entire lifecycle of a system, including the energy it uses over 15 or 20 years, the gap nearly disappears. Lifecycle climate performance analyses show R-32 systems produce about 14,916 kg of CO₂-equivalent emissions over their lifespan, while R-454B systems produce about 15,008 kg. R-32 actually comes out 13.6% lower than R-410A on this measure, compared to 13.1% for R-454B. The reason: R-32 is more efficient, so it burns less electricity, which offsets its slightly higher GWP rating.
Cooling Performance
R-32 delivers more than 110% of R-410A’s cooling capacity, while R-454B manages about 97%. That means an R-32 system can use a physically smaller amount of refrigerant to do the same job. Charge sizes can be up to 40% smaller with R-32, compared to only about 10% smaller with R-454B. For you, that translates to a system that works a bit harder per pound of refrigerant and potentially uses less material overall.
Energy Efficiency
R-32 systems run about 7% more efficiently than equivalent R-410A systems at full load, and seasonal efficiency (the metric that reflects real-world use across varying temperatures) runs 2 to 3% higher. R-454B improves on R-410A efficiency by about 2%. The difference matters most during peak summer heat: R-32 holds its efficiency advantage better at high ambient temperatures, which is exactly when your system is working hardest and your electric bill is climbing fastest.
Servicing and Repairs
This is where a practical difference shows up for homeowners. R-32 is a single-component refrigerant, meaning a technician can top off your system if it develops a small leak without worrying about the chemical composition changing. R-454B is a blend of two chemicals that can leak at different rates. If enough refrigerant escapes, the remaining mixture may no longer have the right ratio, and the entire charge may need to be recovered and replaced rather than simply topped off. That can mean a more expensive service call down the road.
Which Brands Use Which Refrigerant
The North American market is split. Trane began phasing R-454B into its residential products in 2024, starting with its XR15 heat pump line. Carrier, Lennox, and several other major domestic manufacturers have also adopted R-454B for many of their residential lineups. Daikin, the world’s largest HVAC manufacturer, has gone with R-32 across its residential and commercial products, and the company’s own lab data shows up to 12% efficiency gains in inverter-driven systems using R-32.
Globally, R-32 has a much larger installed base. It runs in more than 160 million units across over 100 countries, produced by more than 40 manufacturers. Mini-splits, window units, and variable refrigerant flow systems overwhelmingly use R-32 worldwide. R-454B’s adoption has been concentrated in the U.S. residential market, with limited real-world deployment elsewhere.
Safety With A2L Refrigerants
Both R-32 and R-454B carry the A2L safety classification, meaning they are mildly flammable. This is a step up in flammability from R-410A, which was classified as nonflammable (A1). In practice, “mildly flammable” means these refrigerants can ignite under specific conditions, but they burn slowly and require a relatively high concentration to catch fire. R-454B has a slightly higher threshold before it becomes flammable (352.6 grams per cubic meter versus 306 for R-32), but both are well within the range that safety standards consider manageable for residential use.
New equipment designed for A2L refrigerants is built to updated safety standards that include leak detection sensors and design features to prevent refrigerant from pooling in enclosed spaces. The handling and storage requirements for technicians are similar to what they already follow for pressurized R-410A systems, with some additional precautions around ignition sources during service. As a homeowner, you won’t need to do anything differently. The safety features are built into the equipment itself.
What About Your Car’s AC?
Vehicle air conditioning uses an entirely different set of refrigerants. Most cars made before 2017 use R-134a, which has a GWP of 1,430. Newer vehicles have shifted to R-1234yf, which has a GWP of just 4, essentially negligible. The tradeoff is cost: R-1234yf runs about 20 times more expensive per unit than R-134a. Cooling performance drops modestly too, with the newer refrigerant producing 3 to 7% less cooling capacity and a roughly 4 to 5% lower efficiency rating. For most drivers, the difference in cabin comfort is unnoticeable. If your car already uses R-1234yf, that’s the correct refrigerant for your system, and there’s no option to switch.
If You Still Have an R-22 System
R-22 (commonly known by the old brand name Freon) hasn’t been manufactured or imported into the U.S. since January 2020. Reclaimed and recycled R-22 is still legally available and will continue to be for years, but supply is finite and prices reflect that. If your system runs on R-22, you can keep servicing it with reclaimed refrigerant, but every recharge will cost more than the last. If your system develops a leak, have it repaired rather than simply topped off. Fixing the leak protects your investment and avoids repeated service calls. When the system eventually needs replacement, your new unit will use R-32 or R-454B depending on the brand you choose.
Choosing the Right Refrigerant for a New System
You’re really choosing a brand and model first, and the refrigerant comes with it. No manufacturer offers the same unit in both R-32 and R-454B versions. That said, if refrigerant performance is a factor in your decision, R-32 has clear advantages in efficiency, cooling capacity, and ease of servicing. R-454B has a modestly lower GWP number, but that advantage washes out over the life of the system once energy consumption is factored in.
Both refrigerants are safe, both meet current EPA regulations, and both represent a significant environmental improvement over R-410A. The more important factors for your comfort and your wallet are the equipment’s SEER2 rating, whether the system uses an inverter-driven compressor, and whether it’s properly sized and installed for your home. A well-installed system with either refrigerant will outperform a poorly installed one regardless of what’s flowing through the lines.