The HVAC industry is splitting into two camps as R-410A phases out: R-454B (backed by Carrier, Trane, Lennox) and R-32 (backed by Daikin, Mitsubishi, Fujitsu). Both are A2L "mildly flammable" refrigerants with lower GWP than R-410A. But they're not interchangeable. Here's what matters.
The Specs Side-by-Side
| Property | R-410A | R-454B | R-32 |
|---|---|---|---|
| GWP | 2,088 | 466 | 675 |
| Flammability | A1 (None) | A2L (Mild) | A2L (Mild) |
| Operating Pressure | High | Slightly lower | ~50% higher |
| Efficiency | Baseline | Similar | 5-10% better |
| Charge Size | Baseline | Similar | 20-30% less |
| Major Brands | All (legacy) | Carrier, Trane, Lennox | Daikin, Mitsubishi |
The Key Differences That Matter
GWP: R-454B Wins
R-454B has a GWP of 466 — 30% lower than R-32's 675. Both are under the EPA's 700 threshold, but R-454B is the greener choice on paper.
Efficiency: R-32 Wins
R-32 is a single-component refrigerant (not a blend), which means better thermodynamic properties. Systems using R-32 typically achieve 5-10% better efficiency than equivalent R-454B systems. This translates to lower operating costs. Use our SEER savings calculator to see the impact.
Charge Size: R-32 Wins
R-32 systems need 20-30% less refrigerant by weight. This means smaller components, less material cost, and lower environmental impact if a leak occurs.
Pressure: R-454B Wins
R-32 operates at significantly higher pressures than R-410A. This requires redesigned components rated for higher pressure — meaning existing R-410A-rated parts won't work. R-454B operates at similar pressures to R-410A, making the transition easier for manufacturers.
What This Means for You
If you're buying a new system in 2026-2027:
- Carrier, Bryant, Trane, Lennox buyer? → You'll get R-454B
- Daikin, Mitsubishi, Fujitsu buyer? → You'll get R-32
- Either way: both are safe, efficient, and EPA-compliant
Your existing R-410A system is not affected. You can keep using it and we'll keep supplying OEM parts for it. Use our P/T Chart for any refrigerant.