R-410A replacement: R-410A vs R-454B vs R-32

What changes in the field

US manufacturers replaced R-410A with two A2L refrigerants. R-454B (Carrier’s Puron Advance, Opteon XL41, Solstice 454B and others) is a blend of R-32 and R-1234yf. R-32 is the single-component fluid that made up half of R-410A. Neither one is a refrigerant you put into an R-410A system. The replacement is the whole system.

On the gauges, the three are close but not interchangeable. From the PT data at 100°F condensing, R-410A is 318.5 psig, R-454B 303.3 psig and R-32 325.7 psig. At 40°F evaporating, R-454B dew is 10.9 psi below R-410A and R-32 is 2.6 psi above it. R-454B has about 2.7°F of glide at 40°F, so read dew for superheat and bubble for subcooling. R-410A and R-32 each read off one column.

Moving to A2L work changes your tools. Recovery machines must be certified under 40 CFR 82.158 Appendix B4 (UL 1963 Supplement SB), and OEMs such as Carrier require A2L-rated service equipment. Cylinders carry a red band and often have left-hand thread valves. The A2L refrigerants guide and recovery machine compatibility pages cover the details.

Retrofit or replacement

There is no retrofit path from R-410A to either A2L:

1. EPA’s SNAP listing (86 FR 24444) accepts R-454B and R-32 in residential and light commercial AC only in new equipment meeting use conditions based on UL 60335-2-40. Those cover charge limits and, where required, refrigerant detection and mitigation.
2. Copeland says A2L refrigerants must not be retrofitted into non-A2L compressors or equipment.
3. Carrier states R-454B is not a drop-in replacement. Arkema states there is no retrofit or drop-in replacement for R-410A.

For an existing R-410A system, that leaves two choices:

• Repair it with R-410A. Servicing existing R-410A equipment remains legal. R-410A is an HFC under the AIM Act allowance phasedown: 60% of baseline in 2024–2028, 30% in 2029–2033, 20% in 2034–2035 and 15% from 2036 (40 CFR 84.7). Reclaimed-refrigerant servicing requirements from 2029 do not apply to residential AC.
• Replace it with a matched R-454B or R-32 system. New R-410A split systems may still be installed only where all specified components were manufactured or imported before Jan 1 2025. The 2026 rule (91 FR 31284) removed the earlier installation deadline for those components.

Full dates are on the R-410A phase-out page.

Capacity, efficiency and cost

Arkema, an R-32 supplier, says R-32 offers “higher capacity and better efficiency over R-410A” and a smaller charge. It gives no figure. None of the R-454B sources used here gives a performance percentage. Compare AHRI ratings of the actual matched systems, not refrigerants.

GWP on the AR4 basis is 2,088 for R-410A, 466 for R-454B (EPA’s 40 CFR 84.64 calculation: 465) and 675 for R-32. Both replacements sit under the 700 limit for new residential and light commercial AC and heat pumps (Jan 1 2025) and VRF (Jan 1 2026). On cost, the 2026 final rule preamble discusses R-454B service-cylinder supply shortages.

Common questions

What refrigerant replaced R-410A?

In US residential and light commercial AC, R-454B and R-32, depending on the manufacturer. For the head-to-head comparisons, see R-410A vs R-454B, R-410A vs R-32 and R-454B vs R-32.

Is R-410A being banned?

No ban applies to servicing. The restrictions cover manufacture, import and installation of new equipment with GWP of 700 or more, plus the HFC production phasedown.

Can I still buy an R-410A system?

Only a split system whose specified components were all manufactured or imported before Jan 1 2025. Self-contained (packaged) units are different: manufacture and import stopped Jan 1 2025, and 40 CFR 84.54 allows sale and distribution for three years after that date.