ABSTRACT

A heat pump is any device that extracts heat from a source at low temperature and gives off this heat at a higher temperature. The basic objective of heat pumping is exactly the same as the objective of refrigeration: the heat is removed at a low temperature and rejected at a higher temperature. The difference between these two systems is that a refrigeration system generally transfers heat from a low-temperature object to the ambient, whereas a heat pump transfers heat from the ambient to a higher-temperature object – for example, from a lowtemperature heat source (e.g. air, water or ground) to a higher temperature heat sink (e.g. air or water).