R-454B Refrigerant Explained: What the Switch From R-410A Means for You

If you've shopped for a mini split or heat pump recently, you've probably seen R-454B on the spec sheet instead of R-410A. R-454B is one of the new lower-impact refrigerants that has replaced R-410A in new residential air conditioners and heat pumps in the US. Here's what it is, how it compares, and what it means if you're buying a system or already own one.

What is R-454B?

R-454B is a refrigerant blend made mostly of R-32, mixed with R-1234yf. It's sold under trade names such as Opteon XL41 and Puron Advance. Its main selling point is a much lower global warming potential (GWP) than R-410A: 466, compared with 2,088 for R-410A, using the values EPA applies.

R-454B works at similar pressures to R-410A and delivers similar efficiency, which made it one of the main replacements chosen by manufacturers. The new ACiQ Standard and Extreme multi-zone systems use R-454B.

R-410A vs R-32 vs R-454B

• R-410A was the standard refrigerant in US air conditioners and heat pumps for about two decades. It's non-flammable (safety class A1) but has a high GWP.
• R-32 is a single-component refrigerant with a GWP of 675. Many mini splits use it, including the ACiQ Essentials systems we sell.
• R-454B has the lowest GWP of the three, at 466.

Both R-32 and R-454B are classed as A2L: low toxicity and mildly flammable. In practice, that means they're hard to ignite and burn slowly, and equipment is designed and installed to updated safety standards. Many new A2L systems include refrigerant leak sensors.

Why the switch happened

The American Innovation and Manufacturing (AIM) Act of 2020 directed EPA to phase down high-GWP HFC refrigerants. Under EPA's Technology Transitions rule, new residential and light commercial air conditioning and heat pump systems manufactured or imported in the US from January 1, 2025 must use a refrigerant with a GWP below 700. R-410A doesn't meet that limit; R-32 and R-454B do.

What changed in 2026

The original rule also set a January 1, 2026 deadline for installing new R-410A systems. EPA first said it would not prioritize enforcing that deadline, and in May 2026 issued a final rule removing it for R-410A equipment made or imported before January 1, 2025, according to the Air Conditioning Contractors of America. Some states have their own rules: New York, for example, kept its own January 1, 2026 deadline.

The bottom line: new systems being made today use R-32, R-454B or another low-GWP refrigerant. Remaining stock of older R-410A equipment can still be installed in most states, but supply is shrinking.

What it means if you're buying a mini split

• Choose a current refrigerant. An R-32 or R-454B system is built to current rules and uses a refrigerant that will be easier to service in the long run.
• Use a technician who knows A2L systems. Installation steps are similar, but A2L refrigerants have specific handling, tool and safety requirements. Ask your installer whether they're trained on A2L equipment.
• Don't mix refrigerants. An R-454B system must be charged with R-454B. It can't use R-410A or R-32, and an R-410A system can't be converted to R-454B.
• Line sets may be reusable. When you replace an older system, an existing line set can sometimes be reused if it's the right size and in good condition. Your installer will check and flush it if needed.

Not sure which ACiQ line to choose? Our ACiQ buyer's guide compares Essentials (R-32) with Standard and Extreme (R-454B).

What it means if you already own an R-410A system

Nothing changes right away. You can keep using and servicing an existing R-410A system, and R-410A is still available for repairs. As the HFC phasedown continues, though, R-410A is expected to become more expensive, which can raise the cost of a major refrigerant repair. If an older system needs a big repair, compare the cost with a new, more efficient system before you decide.

Is R-454B safe?

Yes, when the equipment is installed and maintained correctly. A2L refrigerants are mildly flammable, which is why manufacturers design systems to updated safety standards and many include leak detection. In a home, the refrigerant stays sealed inside the system. Only a certified technician should open the refrigerant circuit.

R-454B refrigerant FAQs

Is R-454B better than R-410A?

For the environment, yes: its GWP is about 78% lower. For comfort and efficiency, it performs similarly to R-410A, and systems using it are built to current US rules.

Is R-454B the same as R-32?

No. R-454B is a blend that's mostly R-32 with R-1234yf added, which lowers its GWP. Both are A2L refrigerants, but they aren't interchangeable in a system.

Can I put R-454B in an R-410A system?

No. Systems are designed for one refrigerant, so an R-410A system can't be converted to R-454B.

Do I need special tools for R-454B?

Technicians need tools and recovery equipment rated for A2L refrigerants. Handling refrigerant requires EPA Section 608 certification. That's another reason to have a licensed HVAC technician install your system; see how to install a mini split.

What refrigerant do ACiQ mini splits use?

ACiQ Essentials systems use R-32. ACiQ Standard and Extreme multi-zone systems use R-454B.

Shop ACiQ mini split systems, browse multi zone mini splits, or call us at 512-777-0154 for help choosing a system.