R-454B (brand name Puron Advance) is the primary replacement refrigerant for R-410A in residential and light commercial HVAC equipment. Equipment manufacturers including Carrier, Trane, Lennox, and Daikin began transitioning to R-454B for equipment sold in the US starting January 1, 2025, under EPA regulations implementing the AIM Act.
What Is R-454B?
R-454B is an HFO/HFC blend (68.9% R-32, 31.1% R-1234yf). It is classified as an A2L refrigerant — mildly flammable, meaning it can ignite under specific conditions but has a high minimum ignition energy and very low burning velocity compared to propane or natural gas. Its Global Warming Potential (GWP) is approximately 467, compared to R-410A at 2,088 — a 78% reduction.
Key Properties vs. R-410A
- GWP: 467 (R-454B) vs. 2,088 (R-410A)
- Flammability: A2L (mildly flammable) vs. A1 (non-flammable)
- Operating pressures: Similar to R-410A (slightly lower)
- Capacity: Approximately 95-98% of R-410A in comparable equipment
- Lubricant: POE oil, same as R-410A equipment
- Drop-in replacement: NO — requires equipment designed for R-454B
A2L Safety Requirements
Because R-454B is A2L, new installation and service procedures apply:
- No open flames or ignition sources during refrigerant handling
- Work areas must be ventilated
- HVAC technicians must complete A2L safety training (EPA 608 updates pending)
- Equipment must be A2L-rated — do not use R-454B in equipment rated only for R-410A
- No self-tapping access valves (sparking risk)
- Recovery cylinders must be rated for the specific refrigerant
Tools and Equipment Updates
- New manifold gauges or digital manifold rated for R-454B
- New recovery machine compatible with A2L refrigerants
- New refrigerant scale calibrated for R-454B (different liquid density)
- A2L-rated recovery cylinders (yellow/orange color coding)
- Dedicated hoses — do not cross-contaminate with R-410A hoses
Retrofit and Existing Equipment
R-454B cannot be used in existing R-410A equipment. Existing R-410A systems use R-410A for their service life. R-410A remains available for servicing existing equipment (with phase-down of production, not a ban on use). When R-410A equipment reaches end of life, replacement equipment will use R-454B or another next-gen refrigerant.
Other Next-Gen Refrigerants
- R-32: Used in some mini-split equipment (Mitsubishi, Daikin), also A2L
- R-452B (Opteon XL41): Used in some commercial systems
- R-466A: Non-flammable alternative to R-410A, limited adoption
- R-290 (propane): A3 (highly flammable), used in small self-contained units, growing in commercial refrigeration
Timeline
- Jan 1, 2025: New residential and light commercial HVAC equipment must use low-GWP refrigerants
- R-410A servicing: Continues for existing equipment, no current service ban
- Technician training: A2L training required for working with new equipment