The heat pump as a heating unit takes low temperature heat on the inlet side and gives higher temperature heat on the outlet heating side again. A working fluid evaporates as a result of the taken up ambient heat (air, ground, water). The slightly heated gaseous working fluid is condensed by a compressor, where the temperature rises to a higher level. The high temperature working fluid transfers the heat to the heating water and is cooled. After, the liquid working fluid flows back into the evaporator and the cycle begins again.
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