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R-32 and R-454B: the two refrigerants in recent heat pumps
Two names keep coming up on recent heat pump spec sheets: R-32 and R-454B. The first is a single component; the second is a blend in which R-32 makes up more than two thirds. Both are classed A2L. This guide explains what they are, what their class and GWP mean, what they change at installation and what the rules say. It does not say which one to choose: it is the complete unit that gets compared.
CB22 R-32 · 12,000 BTU
ZE-12CB22AI / ZE-12CB22O · AHRI 218325270
View the product page
CB25 R-454B · 12,000 BTU
ZE-12CB25I / ZE-12CB25O · AHRI 215414830
View the product pageThe refrigerant does not set the bill
Our season-cost estimate starts from each unit’s HSPF2 Region V and SEER2, as certified by AHRI. These ratings vary from one unit to the next, whatever the refrigerant, so this guide shows no dollar amount. The chart places four units sold by AirGreen by their certified HSPF2 Region V; the comparison pages below give the cost in dollars, unit by unit.
A single component, or a blend of two
The refrigerant circulates in a closed loop between the indoor and outdoor units: it picks up heat on one side and releases it on the other. R-32 is difluoromethane, a single molecule. R-454B blends R-32 and R-1234yf; because it has two components, it shows a slight temperature glide, about 1.5 K according to its manufacturer.
Molecules drawn as diagrams (atoms and bonds), not to scale. Composition and glide: Chemours Opteon XL41 (R-454B) fact sheet; R-32: Arkema, Forane 32.
Global warming potential, with its source
GWP compares a gas’s effect with that of CO₂ over 100 years. The values below are from the IPCC Fourth Assessment Report (AR4), the Montreal Protocol reference. R-410A, which both refrigerants replace in new equipment, serves as the benchmark. These numbers describe the gases; they say nothing about a unit’s performance or consumption.
UNEP Ozone Secretariat, list of substances and blends (AR4 values): HFC-32 675; R-410A 2,087.5; R-454B 465.075. Chemours publishes 466 for R-454B (467 under AR5). The page shows 2,088 and 466, rounded.
A, then 2L: what the class says, and what it changes at installation
The ASHRAE 34 standard classes each refrigerant by toxicity (A or B) and flammability (1 to 3, with a 2L subclass). R-32 and R-454B have the same class, A2L. Tap each part to read it.
The IEC 60335-2-40 standard (Annex GG) sets, for flammable refrigerants such as A2Ls, the maximum charge, the minimum room area and the safety measures.
Some A2L units include a sensor. Verified examples: an R-454B sensor in the MIDEA EVOX G3 indoor unit (series spec sheet); a built-in leak sensor in the FUJITSU AIRSTAGE CENTAURI central system (R-32).
Technicians must recognize A2L refrigerant cylinders and use components designed for these fluids, according to Bosch’s A2L guide.
In Québec, installing, servicing or repairing refrigeration or air-conditioning equipment designed for halocarbons requires an environmental halocarbon qualification certificate. The regulation treats a heat pump as air-conditioning equipment.
Chemours presents R-454B as an R-410A replacement in new equipment designs; a unit runs on the refrigerant its manufacturer specifies.
The manufacturer states the refrigerant on its documents: the MIDEA M Thermal Arctic brochure lists “R32” and a GWP of 675; the MIDEA EVOX G3 submittal sheet, “R454B”. The installer follows the model’s installation manual.
Why these refrigerants are arriving now
In Canada, the Ozone-depleting Substances and Halocarbon Alternatives Regulations reduce, step by step, the quantity of HFCs entering the country. In the United States, our largest supply market, the EPA set a GWP limit of 700 for new residential systems. Tap a date to read what it says.
On a small screen, swipe the timeline sideways.
What the refrigerant does not tell you about a unit
Certified efficiency and capacity belong to the complete unit. In the same ZEPHYR series, NEEP certifies an HSPF2 Region V of 7.5 for the CB22 R-32 and 9.0 for the CB25 R-454B; with other brands, the order is reversed.
The NEEP list of ENERGY STAR cold climate units includes units with both refrigerants: for example TOSOT CLIVIA R32 (R-32) and MIDEA EVOX G3 (R-454B). The ZEPHYR CB22 R-32 is not on it.
Compare the certified values of the exact model you are offered: capacity by temperature, HSPF2, SEER2, sound and installation. The refrigerant is one line on the spec sheet.
The questions people ask us about refrigerants
Which of the two is safer?
Both belong to the same ASHRAE 34 class, A2L: lower toxicity, low flammability. The safety of an installation depends on the unit, its charge, the room and following the manufacturer’s instructions, whatever the fluid.
Can R-454B be put into an R-410A unit?
That is not the use its manufacturer describes: Chemours presents R-454B for new equipment designs. A unit runs on the refrigerant its manufacturer specifies.
Is R-410A banned in Canada?
When we checked, the federal regulation reduces, step by step, the quantity of HFCs entering Canada, without setting a GWP limit for residential air conditioners and heat pumps. In Québec, the environment ministry’s FAQ states that, for air-conditioning equipment, only the measures for chillers apply. North American manufacturers follow the 700 limit imposed in the United States since 2025.
Why two GWPs for R-454B, 466 and 465?
Both come from IPCC AR4: Chemours publishes 466, and the Ozone Secretariat list calculates 465.075 from the composition. We show 466 and mention the other.
Does the refrigerant change heating in extreme cold?
Certified performance belongs to the complete unit. R-32 and R-454B units both appear on the NEEP cold climate list; compare their certified values, model by model.
Do R-32 or R-454B deplete the ozone layer?
No: HFCs such as R-32 do not deplete the ozone layer, according to Environment and Climate Change Canada, and Chemours publishes an ozone depletion potential of 0 for R-454B. They are, however, greenhouse gases, hence the GWP.
The two refrigerants, property by property
These lines describe the fluids themselves, according to their manufacturers, UNEP and ASHRAE. They do not measure a unit’s performance; nothing is highlighted.
| Property | R-32 | R-454B |
|---|---|---|
| What it is | ||
| CompositionBy mass | Difluoromethane, 100% | R-32 68.9% · R-1234yf 31.1% |
| Chemical family | HFC | HFC and HFO blend |
| ASHRAE 34 safety class | A2L | A2L |
| Temperature glide | None: a single component | ≈ 1.5 K |
| Climate | ||
| Global warming potential (GWP), IPCC AR4100 years | 675 | 466 |
| Ozone depletion potential | 0 (HFC) | 0 |
| Examples sold by AirGreen | ||
| AHRI certificate · NEEP record12,000 BTU example from the same series | ZEPHYR CB22 · 218325270 · 418044 | ZEPHYR CB25 · 215414830 · 418302 |
| ENERGY STAR cold climate (NEEP) | No, for this example | Yes, for this example |
The last two lines describe two units, not the fluids: with other models, the cold climate listing does not follow the refrigerant.
Both are on the AirGreen website.
The refrigerant is one line on the spec sheet; the unit is the project. Talk to our team: bring the area to heat, your current heating and the planned outdoor location.
Where every number comes from
Data verified on November 9, 2026. This guide explains two refrigerants; it ranks neither the fluids, nor the units, nor the brands. The rules cited are summarized; only the official text governs.
Trademarks. ZEPHYR, TOSOT, MIDEA, FUJITSU AIRSTAGE, Opteon and Forane are trademarks of their respective owners. Logos are used only to identify the products shown. AirGreen is a retailer of the equipment brands cited; this page is not produced, sponsored or endorsed by the manufacturers.
Photos: AirGreen and manufacturers, for identification.
Does a figure look wrong? Write to us : every reported figure is checked again.