R290 (propane)
R290 is propane used as a natural refrigerant. It has a very low global warming potential, but is flammable and therefore requires safety precautions.
- Evaporator: the cold refrigerant absorbs heat from the air, ground or water and evaporates.
- Compressor: it compresses the vapour, which increases the temperature. Electricity is needed here.
- Condenser: the hot vapour releases its heat to the heating water and becomes liquid again.
- Expansion valve: the pressure drops, the refrigerant cools down, and the cycle starts all over again.
R290 is the technical name for propane when it is used as a refrigerant in heat pumps. It is one of the natural refrigerants.
Why R290 is becoming more important
klimaaktiv classifies R290 in the group with very low global warming potential, with a GWP below 10. For comparison: many previously common fluorinated refrigerants are in the range of several hundred to over 1.500. EU Regulation 2024/573 is phasing out fluorinated gases with a high GWP in new heat pumps. Refrigerants like propane are not affected by this because they are not fluorinated greenhouse gases.
Safety
Propane is flammable. According to the Bundesverband Wärmepumpe (German Heat Pump Association), propane heat pumps contain more than 150 grams of it. To put this into perspective, the association states that a small barbecue gas cylinder contains more propane than a heat pump for a single-family home. Manufacturers secure the devices in accordance with the relevant standards. According to the association, additional measures such as gas sensors and an exhaust air duct to the outside are required for indoor installation. Therefore, propane devices are often installed outdoors as a monobloc.
What this means for you
- Observe the safety zones around the outdoor unit specified by the manufacturer. Your installer knows them and will plan the location accordingly.
- Work on the refrigerant circuit must always be left to professionals.
You can check whether your desired device is eligible for a subsidy under eligible device.
Sources
- klimaaktiv Wegweiser zur guten Installation von Wärmepumpen (klimaaktiv Guide to Good Installation of Heat Pumps, BMK, 2020) (accessed on 4 October 2026)
- Bundesverband Wärmepumpe (BWP): Refrigerants (accessed on 4 October 2026)
- Regulation (EU) 2024/573 on fluorinated greenhouse gases (EUR-Lex) (accessed on 4 October 2026)