Kit desk · chart page
R32 vs R290 refrigerant: the numbers and the rules
R32 vs R290 refrigerant in numbers: R32 has a global warming potential of 675 and R290 just 3, against 2,088 for the older R410A.
By the Cooler Indoors desk · figures checked · 4 charts · sources · methods
The R32 vs R290 refrigerant question is mostly about climate impact and handling. R32 (difluoromethane) has a global warming potential, or GWP, of 675; R290 (propane) has a GWP of 3. Both sit under the GB cap that pushed R410A out of new small split systems, and both wall splits on our spec-sheet list use R32.
What is the GWP of R32, R290 and R410A?
R32 scores 675, R290 scores 3 and R410A scores 2,088. GWP compares a gas's warming effect with carbon dioxide, kilogram for kilogram, so a kilogram of R32 that escapes counts as 675 kg of CO2 equivalent.
Source: legislation.gov.uk, Regulation (EU) No 517/2014 as retained, Annex IV · checked 29 October 2026
How we read this R32 is listed in Annex I and R290 in Annex IV. R410A is a 50/50 blend, so its 2,088 is the weighted average the regulation prescribes (2,087.5, rounded), not a single printed figure.
Show the numbers
| Label | GWP | Note |
|---|---|---|
| R410A | 2,088 | |
| R32 | 675 | |
| R290 (propane) | 3 |
R410A is half R32 and half HFC-125, and HFC-125 alone has a GWP of 3,500. That is why the blend sits three times higher than R32 on its own.
Why can't new small split systems use R410A any more?
Because since 2025 GB has banned refrigerants with a GWP above 750 in new single-split systems holding less than 3 kg. R410A, at 2,088, is well over that line; R32, at 675, is just under it. Portable air conditioners face a tighter cap: HFCs with a GWP above 150 are already banned in movable units, which rules out R32 in a new portable.
On video: Which refrigerant is better R32 or R290?
“Which refrigerant is better R32 or R290?”, a video from the Rinnai UK channel on YouTube. Rinnai UK compares R32 and R290 on GWP (675 vs 3, against 2,088 for R410A), efficiency, flammability and cost, and mentions the UK F-gas regulation. It is their video, not ours, and it loads from YouTube only when you press play.
Source: GOV.UK, Bans on F gas in new products and equipment · checked 29 October 2026
How we read this Limits for new equipment in Great Britain, page updated 27 August 2026. Northern Ireland sits inside the EU F-gas system, whose rules we have not charted.
Show the numbers
| Label | GWP | Note |
|---|---|---|
| Single split under 3 kg | 750 | |
| Movable (portable) unit | 150 |
GB's government consulted in September 2025 on a revised HFC phase-down. We found no published response or new regulation, so the 750 cap above is the rule in force as far as we can confirm.
How much refrigerant triggers a legal leak check?
It depends on the CO2 equivalent, which is the charge in kilograms multiplied by the GWP. Equipment holding 5 tonnes CO2e or more needs a leak check at least every 12 months; from 50 tonnes it is every 6 months, and from 500 tonnes every 3 months. GOV.UK says those intervals double where a leak detection system is fitted, and hermetically sealed systems under 10 tonnes are exempt.
Source: GOV.UK, Checking F gas equipment for leaks · checked 29 October 2026
How we read this Worked example, not a measurement: 5,000 kg CO2e divided by each GWP. GOV.UK prints the R410A figure; the R32 figure (5,000 ÷ 675) is our arithmetic.
Show the numbers
| Label | kg | Note |
|---|---|---|
| R410A | 2.4 | |
| R32 | 7.4 |
Source: GOV.UK, Checking F gas equipment for leaks · checked 29 October 2026
How we read this Longest gap allowed between checks when no leak detection is fitted. The thresholds are tonnes of CO2 equivalent, not kilograms of refrigerant.
Show the numbers
| Label | months | Note |
|---|---|---|
| 5 to under 50 t CO2e | 12 | |
| 50 to under 500 t CO2e | 6 | |
| 500 t CO2e and over | 3 |
Propane is a hydrocarbon rather than a fluorinated gas, and with a GWP of 3 it barely registers on a CO2e scale built for F gases. Routine servicing still matters whatever the gas; our servicing page covers what owners can do.
Is R290 harder to handle safely than R32?
Both are flammable, R290 more so: it is propane. That is one more reason refrigerant circuits are a specialist job. Whatever the gas, leave the circuit to an F-gas certified engineer working for a certified company. There is no safe or legal DIY refrigerant work, no DIY pipe connection and no home re-gassing. GOV.UK says it is illegal to buy F gas, or sell it to someone, without the correct qualifications.
For systems under 3 kg, the engineer needs at least a category 2 certificate, which covers installing, servicing and recovering refrigerant from them.
What does the refrigerant choice change for a homeowner?
Mostly it changes the paperwork and the climate cost of a leak, not the daily routine. Check the refrigerant line on the spec sheet: Fujitsu's ASEH09KNCA page names R32 and its GWP of 675. Your own jobs stay the same with any gas: switch off at the isolator before touching the unit, clean or rinse the filters as the maker's manual says, keep leaves clear of the outdoor unit and check the condensate drain is not blocked. Anything beyond that belongs to the engineer.
| Refrigerant | What it is | GWP | New small single split (GB) | New portable (GB) | Source |
|---|---|---|---|---|---|
| R410A | Blend of HFC-32 and HFC-125 | 2,088 | Banned since 2025 | Banned | Reg. 517/2014 Annex IV |
| R32 | Difluoromethane (HFC-32) | 675 | Allowed | Banned (above 150) | Reg. 517/2014 Annex I |
| R290 | Propane | 3 | Allowed | Allowed | GOV.UK F-gas bans |
| Who may handle it | F-gas certified engineer and company | GOV.UK F-gas qualifications, selling F gas |
Questions this data raises
Is it legal to buy R32 to keep in the shed for later?
No. Buying F gas without the right qualifications is against the law, and only a certified engineer working for a certified company may re-gas a system.
Will my existing R410A system become illegal to run?
The GB ban we cite applies to new products and equipment. Existing systems still fall under the leak-check rules, which for R410A start at about 2.4 kg of charge.
Why does 1 kg of leaked R32 count as 675 kg of CO2?
That is what a GWP of 675 means: over the standard comparison period, a kilogram of R32 warms the climate as much as 675 kg of carbon dioxide.
Is a propane (R290) unit safe to have indoors?
Propane is flammable, so makers limit how much charge a unit may hold for the size of room it serves and set out where it can be fitted. That is one more reason the siting and installation belong to a certified engineer following the maker's instructions.
Sources for this page
- legislation.gov.uk, Regulation (EU) No 517/2014 as retained, Annex IV legislation.gov.uk
- GOV.UK, Bans on F gas in new products and equipment gov.uk
- GOV.UK, Checking F gas equipment for leaks gov.uk
- Reg. 517/2014 Annex I legislation.gov.uk
- GOV.UK F-gas qualifications gov.uk
- selling F gas gov.uk
All checked 29 October 2026. How we choose and read sources: Methods & sources.