Our heat pump absorbs heat from the surrounding air by pumping it using a fan into an evaporator that contains a non CFC refrigerant with a very low boiling point.The liquid refrigerant turns to gas in the evaporator and goes through the compressor which pumps it through a small valve compressing it while generating a lot of heat and pressure. The heated gas goes through a coiled copper tube heat exchanger in the water tank and heats the water. Heat pumps mainly consist of a compressor, fan, evaporator, and the heat exchanger.