What Is R-454B and R-32 Refrigerant?
What this costs
| Option | Job | Low | High |
|---|---|---|---|
| Replace | Heat Pump Installation | $4,450 | $11,600 |
Why you're hearing about them
EPA's AIM Act rules limit new home AC and heat pump systems to a global warming potential below 700. EPA's list shows R-410A at 2,090, well over that limit, so new equipment moved to other refrigerants. EPA's list, last updated March 19, 2026, marks both of these as acceptable with use conditions.
- R-454B: global warming potential 470, class A2L.
- R-32, also called HFC-32: global warming potential 675, class A2L.
What 'mildly flammable' means for you
EPA describes these as mildly flammable and lists them as acceptable only with use conditions. We don't see that as a reason to panic, but it's no reason to handle them yourself. Ask your installer how the system you're buying meets the conditions for your home.
What it means when you replace a system
When you get quotes, ask what refrigerant each system uses and whether the existing refrigerant lines or indoor coil can stay. If only the outdoor unit is being replaced, ask the installer to explain what EPA allows in your situation.
What it means when you repair a system
An existing R-410A system stays on R-410A. EPA says industry standards and its own rules don't allow R-454B or R-32 in systems not designed for them, so a technician can't simply top off an old system with them. We recommend a licensed HVAC technician for refrigerant work.
What isn't settled
We didn't find an official source that says which of these two is better for a house, and we don't recommend one over the other. Compare the whole quote instead: efficiency, warranty and the installer's experience with this equipment.
Common questions
Is R-454B the same as R-410A?
Which is better, R-454B or R-32?
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Last verified 2026-11-04
- EPA SNAP: Substitutes in residential and light commercial air conditioning and heat pumps (updated Mar. 19, 2026) — R-454B GWP 470 and HFC-32 GWP 675, both ASHRAE class A2L and acceptable with use conditions; R-410A GWP 2,090.
- EPA: Frequent questions on the phasedown of hydrofluorocarbons — R-32 below the 700 limit; mildly flammable refrigerants may not be used in systems not designed for them.
- EPA: Technology Transitions HFC restrictions by sector (updated Aug. 28, 2026) — GWP limit of 700 for residential AC and heat pump systems.
General information, not professional advice. Conditions, codes and prices vary. Turn off power, gas or water before any work, and hire a licensed professional when in doubt. Cost figures are our estimates, not quotes.