GWP (Global Warming Potential) measures how much warming one kilogram of a gas causes over 100 years compared with one kilogram of CO2, which scores 1. Refrigerant examples: R410A about 2,088, R32 about 675, R290 propane roughly 0.02. The EU F-Gas Regulation 2024/573 uses GWP thresholds of 150, 750 and 2,500 to ban refrigerants from new equipment and from servicing.
How is GWP calculated?
GWP integrates the warming effect of one kilogram of a gas over a fixed horizon — almost always 100 years — and divides it by the same integral for CO2. A GWP of 675 means one kilogram of that gas warms the atmosphere as much as 675 kg of CO2 over a century. The values come from IPCC assessment reports and shift slightly between editions (AR4, AR5, AR6) as atmospheric science refines; datasheets and EU quota arithmetic historically use AR4-based values, which is why the same refrigerant can show marginally different numbers in different documents. The horizon matters too — over 20 years, short-lived gases score far higher — but refrigerant regulation settled on the 100-year value for comparability.
Multiplying refrigerant charge by GWP gives the CO2-equivalent (CO2e) — the figure EU law uses for quotas and leak-check obligations.
What are the GWP values of common refrigerants?
| Refrigerant | GWP | CO2e of a 2 kg charge |
|---|---|---|
| R404A (legacy refrigeration) | 3,922 | 7.8 tonnes |
| R410A | 2,088 | 4.2 tonnes |
| R134a | 1,430 | 2.9 tonnes |
| R32 | 675 | 1.35 tonnes |
| R290 (propane) | 3 (AR4) / ≈0.02 (AR6) | ~0.04 kg |
| R744 (CO2) | 1 | 2 kg |
The spread is the story: two identical-looking heat pumps can differ in refrigerant climate liability by five orders of magnitude. Cell-level chemistry, not efficiency, decides that column — a refrigerant choice made at the factory.
How does the EU F-Gas Regulation use GWP?
Regulation (EU) 2024/573 is built around three GWP thresholds. GWP 150 gates new equipment: monoblock and air-to-water split heat pumps up to 12 kW must stay below it from 1 January 2027. GWP 750 applies to larger split systems from 2029, tightening to 150 in 2033. GWP 2,500 governs servicing: virgin refrigerants above it are banned for maintaining existing equipment, extending to heat pump and AC equipment from 2026 with transitional allowances for recycled refrigerant.
The phase-down quota is likewise denominated in GWP terms: 42.9 Mt CO2e of HFCs may be placed on the EU market in 2025–2026 — about 48% below the 2023 level — falling to roughly 21.7 Mt in 2027–2029, near 9 Mt from 2030, and zero HFCs by 2050. A low-GWP kilogram consumes almost no quota, which is exactly the commercial pressure the regulation intends. The regulation's annexes fix the GWP value assigned to each listed gas, so compliance never depends on which IPCC edition a datasheet happens to quote.
What GWP should you look for when buying a heat pump?
Below 150 is the future-proof answer: natural-refrigerant units — in practice R290 propane monoblocks and equivalents — are untouched by every ban step through 2035 and immune to quota-driven refrigerant inflation. The nameplate and energy label state the refrigerant, its GWP and the charge's CO2e; statutory leak-check frequency for larger systems scales with that CO2e figure. For the complete ban calendar and what it means for each product category, see the EU F-Gas guide. Heat pumps themselves remain the decarbonisation tool regardless of refrigerant — Europe bought 2.88 million of them in 2025 (EHPA, +13%) — and manufacturers such as Solimpeks design product lines around the sub-150 future.
Frequently asked questions
Is a low-GWP refrigerant less efficient?
No — there is no physical link between GWP and efficiency. R290, with a GWP near zero, is among the best-performing heating refrigerants available, reaching flow temperatures of 70–75 °C. Efficiency depends on the refrigerant's thermodynamics and the system design, not its climate score.
Why do GWP values differ between sources?
Because IPCC assessment reports update them: R32 is 675 in AR4 and 771 in AR6, and R290 falls from about 3 to 0.02. EU regulation fixes the applicable values in its annexes so that quotas and labels stay comparable across manufacturers.
What is CO2 equivalent (CO2e)?
The refrigerant charge in kilograms multiplied by its GWP. A 2 kg charge of R410A equals about 4.2 tonnes of CO2e. The EU uses CO2e for its HFC quota, for leak-check frequency thresholds and for equipment labelling.
Does GWP matter if the refrigerant never leaks?
Yes. Real systems lose refrigerant during service events, faults and end-of-life recovery, and statistics rather than intentions drive the law. GWP also determines how a product is treated under the regulation — which new-equipment limits apply, and how its service refrigerant is priced under the quota.