How a heat pump works
- Brine* circulates in a collector coil and absorbs the heat energy from bedrock, ground, air or water.
- At the heat exchanger (evaporator) the tepid brine in the collector coil meets the ice-cold refrigerant** in the heat pump, which is then heated a few degrees and evaporates.
- Then, a compressor compresses the refrigerant. The heat that is then generated is transferred via a heat exchanger (condenser) to the house’s heating system.
- The refrigerant circulates and an expansion valve lowers the pressure and the refrigerant becomes cold again. The process begins again when the refrigerant meets the tepid brine from the collector coil.
* The brine is a mixture that cannot freeze, for example alcohol or glycol.
** Modern environmentally sound refrigerant are used, e.g. hydrocarbons and carbon dioxide. Formerly, freon was used.