Is R32 better than R410A?

For new units, yes. R32 has about a third of R410A's global-warming potential (≈675 vs ≈2,088), is modestly more efficient, and is a single-component refrigerant so it's easier to top up correctly. R410A is being phased down under EU F-Gas and the US AIM Act, so R32 (and blends like R454B) are what new systems use.

Is R290 (propane) refrigerant safe in an air conditioner?

Yes, in a properly sealed unit. R290 is propane, so it's flammable (safety class A3), which is why it's used in smaller, charge-limited systems like portables and monoblocs and handled by trained installers in fixed units. In return it has a near-zero global-warming potential (≈3) and excellent efficiency.

Should I avoid air conditioners that use R410A?

Not necessarily — an R410A unit works fine and is safe to run. But R410A is being phased down, so it's older stock: newer R32 or R454B units are more efficient and more future-proof, and refrigerant for servicing an R410A system will get scarcer and dearer over time.

What refrigerant do new air conditioners use?

Most new splits and mini-splits use R32. Many portables and monoblocs use R290 (propane). In the US, newer systems increasingly use R454B as the lower-GWP R410A replacement. We show each unit's refrigerant in the comparison where the listing states it.

Air Conditioner Refrigerants Explained: R32 vs R290 vs R410A

Published: May 25, 2026

The refrigerant is the working fluid that actually moves heat. Which one a unit uses tells you something about its efficiency, environmental footprint, and how cheap it’ll be to service in a few years — so we show it in the comparison wherever the listing states it. Here’s what the codes mean.

The numbers that matter

Refrigerant	GWP (vs CO₂)	Safety class	Typical use	Notes
R290 (propane)	~3	A3 (flammable)	Portables, monoblocs	Lowest GWP, very efficient, charge-limited
R32	~675	A2L (mildly flammable)	New splits & mini-splits	Efficient, single-component, now the standard
R454B	~466	A2L	Newer US systems	The main R410A replacement
R134a	~1,430	A1 (non-flammable)	Older/auto/portable	Higher GWP, being designed out
R410A	~2,088	A1	Older splits	High GWP, being phased down

GWP (global-warming potential) is how much heat a kilogram of the refrigerant traps versus a kilogram of CO₂ over 100 years. Lower is better — and it matters in practice because regulators are phasing down high-GWP refrigerants.

Why it’s changing

Both the EU’s F-Gas Regulation and the US AIM Act are cutting the supply of high-GWP refrigerants. That’s pushed the industry off R410A and onto lower-GWP options — R32 for most splits, R454B in newer US systems, and R290 where a very low charge is feasible. The practical upshot for a buyer: a high-GWP unit isn’t broken, but it’s the trailing edge, and the refrigerant to service it will get rarer and pricier.

R32 vs R410A (the common choice)

This is the comparison you’ll meet most often on splits and mini-splits:

GWP: R32 ≈675 vs R410A ≈2,088 — about a third.
Efficiency: R32 has better heat-transfer properties, so R32 systems are typically a few percent more efficient for the same design.
Servicing: R32 is a single compound, so it can be topped up without changing its composition; R410A is a blend that must be charged as liquid and fully replaced if it leaks. R32 is also being produced at scale while R410A supply shrinks.

R32 is mildly flammable (A2L) versus R410A’s non-flammable A1, which mainly affects installation rules, not day-to-day use.

R290 — the low-GWP outlier

R290 is propane: a GWP of about 3 and excellent thermodynamics, which is why you’ll see it in portables and monoblocs. The catch is flammability (A3), so it’s restricted to small refrigerant charges and, in fixed systems, professional handling. For a self-contained portable, it’s a genuinely green, efficient choice.

What to buy

For a new fixed unit, R32 (or R454B in the US) gives you the best mix of efficiency, lower GWP and future-proof servicing. For a portable, R290 is the greenest, most efficient option. An R410A unit is fine to run today but is older stock — weigh its price against shorter future serviceability. Either way, the refrigerant is one input; rank by cost per hour to run first.

Next: SEER vs EER efficiency explained · what’s a good cost per hour? · air conditioners ranked by running cost