Hydrocarbons (HCs) propane and isobutane are naturally occurring substances with very low GWP. Thermodynamically, they are very good refrigerants, but they are flammable. So far, their use is limited to applications with very small refrigerant charges in which ignition points such as relays, switches and thermostats are isolated and protected. Applications include domestic and small commercial refrigerators and freezers.
Hydrocarbon use is quite common in Europe and Asia. Several US manufacturers are now moving to HCs, and the US regulatory process is being adapted to permit HC refrigerant use. In EU, hydrocarbons could be used in commercial applications (charge above 150g), with strict requirements for the safety of the installations. Another promising application is heat pumps, in which hydrocarbons (particularly propane) are extremely efficient.
Danfoss can supply controls and is developing compressors for these applications. (For many years the petrochemical industry has also used hydrocarbons – actually in very large systems where we sell our industrial refrigeration products. Of course the petrochemical industry knows to handle the risk of flammable substances and has the technical skills.)
The following document provides a guide to hydrocarbon-friendly components offered by Danfoss: