GWP (global warming potential)

The GWP value shows how much a refrigerant contributes to global warming if it escapes. CO2 has a value of 1; the lower, the better.

GWP stands for "Global Warming Potential" (Treibhauspotenzial in German). The EU regulation on fluorinated greenhouse gases defines it as the global warming potential of a gas relative to carbon dioxide, based on 1 kg and a period of 100 years. CO2 therefore has a value of 1. A refrigerant with a GWP of 675 is therefore 675 times as potent as CO2 per kilogram.

Why this matters for heat pumps

Every heat pump contains a refrigerant. In normal operation, it remains in a closed circuit. If it escapes into the environment due to damage, the GWP determines how harmful to the climate it is. klimaaktiv emphasises that refrigerants with a very high GWP should nevertheless be avoided.

Rough classification according to klimaaktiv

• Very high, over 1.500: such as R410A, R407C
• High, 800 to 1.500: such as R134a
• Medium, 10 to 800: such as R32, R454B
• Very low, below 10: such as R290 (propane), R744 (CO2)

Legal framework

EU Regulation 2024/573 gradually limits the GWP for new appliances. For example, self-contained heat pumps (monobloc) up to 12 kW must not contain fluorinated gases with a GWP of 150 or more from 1 January 2027, unless safety requirements at the location demand it. The same limit also applies to air-to-water split systems up to 12 kW from 2027.

Ask in the quote about the refrigerant and its GWP. A low value is also an advantage for maintenance and public subsidies, see eligible appliance.

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