R290 is a propane that is a flammable hydrocarbon. Therefore, it is often used as LP gas. Since it has such a strong flame, it is a material that is difficult to use in air conditioners, but it is a natural refrigerant, and because GWP is very low, and enough performance is obtained as a device, it is recommended to introduce it to the room air conditioner now in Europe and China. Already Japan Noritz sells equipment using this refrigerant as a heat pump water heater.

Refrigerant number
Other namesPropane
CategoryHC (Hydro carbon)
Molecular structure
GWP< 3
Safety classificationFlammable, non-toxic (A3)