R-410A vs R-454B Refrigerant: What It Means + What to Buy

R-410A and R-454B are refrigerants used in modern HVAC systems, but they are not interchangeable. Starting January 1, 2025, new residential HVAC equipment began transitioning away from R-410A toward newer refrigerants, mainly R-454B and R-32. MRCOOL chose R-454B, which is now the primary refrigerant used in their next-generation residential mini splits and heat pumps. If you’re buying a new system in 2026, you should expect it to use R-454B (or in some cases R-32), while R-410A systems and parts will still be supported for years.

Last updated: January 2026

Key Takeaways

• R-410A and R-454B are not compatible and cannot be swapped
• The HVAC industry began shifting away from R-410A on Jan 1, 2025
• Manufacturers moved to either R-454B or R-32
• MRCOOL chose R-454B (like most manufacturers)
• You can still buy many R-410A parts and some systems today, but new system options will shrink over time
•  If you already own an R-410A system, you don’t need to panic. Support and parts will remain available for a long time

What Is R-410A?

R-410A was the standard refrigerant used in residential air conditioners, heat pumps, and mini splits for many years. It replaced R-22 and became the “default” refrigerant for modern systems.

Millions of homes in the U.S. still run on R-410A equipment today, which is why:

• replacement parts are still widely available
• service support will continue for years
• older systems are still common and repairable

What Is R-454B?

R-454B is a newer refrigerant used in next-generation residential HVAC systems. It’s part of the industry-wide transition away from R-410A and is now used in many new models across major manufacturers.

MRCOOL chose R-454B as the refrigerant platform for their newer residential systems, aligning with the direction most manufacturers are taking moving forward.

What Changed on January 1, 2025?

Starting January 1, 2025, new residential HVAC equipment began transitioning away from R-410A.

Manufacturers were able to choose their next refrigerant platform, and the two main options became:

• R-454B
• R-32

MRCOOL joined the majority of manufacturers and selected R-454B.

This transition is similar to what happened with R-22 years ago:

• older systems remain in service
• parts remain available for a long time
• new equipment gradually shifts to the new standard

R-410A vs R-454B (Quick Comparison)

Is R-410A Still Legal to Sell?

In many cases, yes. R-410A systems and parts may still be available and sellable depending on category and inventory availability.

Right now:

• R-410A replacement parts are still allowed and expected to remain available for some time
• some R-410A systems may still be sold (especially remaining inventory)
• over time, the availability of new R-410A residential systems will continue to shrink

The key point is that the market is moving forward, and new system options will increasingly be R-454B (or R-32).

Can You Replace R-410A With R-454B?

No. R-410A and R-454B are not interchangeable, and you should not:

• mix refrigerants
• “top off” with the wrong type
• try to convert a system to a different refrigerant

HVAC systems are engineered around a specific refrigerant, oil type, pressure characteristics, and safety requirements.

Always match the refrigerant to the system nameplate.

What About R-32?

R-32 is another refrigerant manufacturers may use in newer residential systems. In real-world performance, R-32 and R-454B are very similar, and for most homeowners, it won’t feel “better” or “worse” from a comfort standpoint.

There’s speculation in the industry that:

• R-454B may become the dominant long-term standard
• and rumors suggest R-32 could be phased out in the next 5 years

But that part is not confirmed, and should be treated as speculation rather than guaranteed policy.

What Should You Buy in 2026? (Simple Answer)

If you’re buying a NEW residential mini split or heat pump:

Expect it to be R-454B (MRCOOL) or R-32 (some other manufacturers).

If you’re replacing an older system:

You may still find an R-410A system, but the long-term direction is clearly toward newer refrigerants. In many cases, it makes sense to move forward with the newest platform available.

If you already own an R-410A system:

You do not need to replace it just because of refrigerant changes. R-410A systems will remain serviceable, and parts will still be available for years.

How to Tell What Refrigerant Your System Uses

The fastest way to confirm refrigerant type is to check:

• the outdoor unit nameplate
• the model specifications
• your product listing details

If it says R-410A, it must be serviced with R-410A.
If it says R-454B, it must be serviced with R-454B.

Common Mistakes to Avoid

Mistake #1: Buying refrigerant without checking the nameplate
Always confirm refrigerant type first.

Mistake #2: Assuming “new refrigerant” automatically means “better comfort”
Comfort depends more on sizing, install quality, and airflow than refrigerant type.

Mistake #3: Thinking R-410A systems will disappear overnight
Millions of R-410A systems exist and will be supported for a long time.

FAQ

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

No. They are not compatible. Use only the refrigerant type listed on the unit nameplate.

Is R-410A being phased out?

Yes, for new residential systems. The industry began transitioning away from R-410A on Jan 1, 2025, but existing systems will be supported for years.

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

R-454B is the newer refrigerant platform used in new equipment moving forward. Comfort and performance depend more on system design and installation quality than refrigerant alone.

Is R-32 better than R-454B?

Performance is very similar. The bigger difference is which platform a manufacturer chose moving forward.

Will parts still be available for R-410A systems?

Yes. R-410A replacement parts should remain available for a long time because so many systems are still in service.

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