Heat pumps

Thermal heat pumps operate on the principle of transferring thermal energy from external air to the indoors. The heat carrier (refrigerant) passes through the expander (where its pressure falls as does the temperature), then it goes to the external unit where the cooled heat carrier “takes away” low-potential heat, further into the compressor (where pressure and temperature rise) and, at last, in the internal unit– where heat exchange with internal air takes place .