R-454B (brand name “Opteon XL41” or “Puron Advance”) is one of the new low-GWP refrigerants replacing R-410A in residential HVAC equipment. It’s the choice most major manufacturers (Carrier, Trane, Lennox) have selected for their 2025+ product lines.
Why the switch
R-454B has a Global Warming Potential of about 466 — roughly 78% lower than R-410A’s 2,088. The EPA’s AIM Act mandates a phase-down of high-GWP refrigerants in residential HVAC, and R-454B meets the requirements while remaining mostly compatible with existing system designs.
What this means for installs in 2026
- New ACs and heat pumps you install today likely use R-454B
- R-454B is mildly flammable (A2L classification) — requires updated installation practices but is safe in normal use
- Service technicians require updated training and tools (we have them)
- Parts and refrigerant are widely available
R-454B systems are not significantly more expensive than the final-generation R-410A systems. There’s no consumer downside to choosing a new R-454B system today.
Related: Refrigerant, R-410A.
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Right Way Mechanical is a family-owned HVAC contractor serving Wheat Ridge, Arvada, west Denver, and the Colorado foothills.