Both replaced R-410A in new equipment starting in 2025. Here's how they actually compare — GWP, safety class, performance — and which manufacturers use which.
R-32 and R-454B are the two refrigerants that have effectively replaced R-410A in new residential central AC and heat pump equipment sold since 2025 — manufacturers' answer to the AIM Act phasedown described in the previous article. Both are classified ASHRAE A2L: mildly flammable, a step up in risk from R-410A's non-flammable A1 rating, but well short of a genuinely flammable refrigerant like propane. That A2L classification isn't just a label — it requires leak-detection sensors, different electrical components, and specific charge limits that didn't exist in R-410A equipment, so this is a real engineering change under the hood, not a relabeled can of gas going into the same old box.
| R-32 | R-454B | |
|---|---|---|
| Global Warming Potential (GWP) | 675 | 466 (about 31% lower) |
| Flammability class | A2L | A2L |
| Approx. pressure at 95°F | 303 psig | 280 psig |
| Volumetric capacity | Baseline | About 10–15% lower than R-32 |
In practice, the pressure difference is small enough that service equipment and procedures are similar for both. R-32's higher volumetric capacity can let engineers use a somewhat smaller compressor or coil for the same output — but for a properly engineered system on either refrigerant, day-to-day comfort, capacity, and efficiency should feel about the same to you as a homeowner. The difference matters more to the engineers designing the equipment than to how your house feels.
A manufacturer can use different refrigerants across different product lines — Trane's own materials describe "most" of its residential products as R-454B but note "some" use R-32. The brand tells you the likely default, not a guarantee. If it matters to you (it will, for servicing — see below), ask your contractor which refrigerant the specific model on your quote uses, or check the equipment's nameplate/spec sheet directly.
You generally can't pick a refrigerant independent of the equipment brand and model — it's baked into which system you're buying, not an à la carte option the way a SEER tier might be. And once you own the system, that's what it gets serviced with for its life: R-32 and R-454B aren't interchangeable in the field, so whichever your installed system uses is what any future technician needs on hand for a repair. It's a small but real reason to know the answer before you sign, not just after something breaks.
HVAC Referee checks your actual quote against equipment, installation, and pricing standards — including which refrigerant and efficiency tier you're being quoted.