R-454B vs. R-32: Which Refrigerant Wins at Low-Temperature Heating with EVI?
Why This Matters
As the HVAC industry transitions away from high-GWP refrigerants like R-410A, two contenders — R-32 and R-454B — are leading the pack. Both work with Enhanced Vapor Injection (EVI), the technology that lets heat pumps keep homes warm in freezing weather.
But which refrigerant actually performs better when the temperature drops into the teens — or even below zero?
The Showdown: R-32 vs. R-454B in Low-Temp Heating
| Feature | R-32 | R-454B |
|---|---|---|
| Type | Pure refrigerant | Blend (≈69% R-32 + 31% R-1234yf) |
| GWP | 675 | 466 |
| Capacity in Cold Temps (with EVI) | Higher – holds more rated capacity in deep cold (5–10% advantage) | Lower – slight loss vs. R-32 due to R-1234yf dilution |
| Efficiency with EVI | Stronger heat transfer; higher COP in most studies | Lower efficiency; glide complicates heat exchange |
| Discharge Temps | Higher – can stress compressors | Lower – gentler on compressor under strain |
| Durability | Requires robust compressor design | Easier on components long-term |
| Best Fit | Cold-climate performance where max heating output is critical | Eco-friendly replacement where durability & regulatory compliance matter |
What This Means for Homeowners
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Choose R-32 + EVI if you live in a region with harsh winters (New England, upper Midwest, Rockies). You’ll keep more heating capacity when you need it most.
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Choose R-454B + EVI if your region is milder but you want the lowest GWP and a refrigerant that’s easier on the compressor.
Both refrigerants will comfortably heat most U.S. homes down to well below freezing, but R-32 provides the stronger low-temperature punch.
Takeaway: If “superheating," or getting down to super low temperatures, is your priority, R-32 is the winner. R-454B is greener, but a little weaker when the cold gets extreme.