PURPOSE: To perform an efficient feeding-out of cooling cold water or hot water for heating or hot water supply at about 80°C with not-yet utilized energies such as sewage, sea water, river water, lake water and various low temperature discharged gases and the like being applied as heat source and no specified fluorocarbon is used.

CONSTITUTION: A vapor compression type heat pump 1 is combined with a heat source machine 2 capable of changing-over between a double-effective absorption freezer and a single effective absorption heat pump. In the case that cooling cold water is taken out, the heat source machine 2 is used as a double effective absorption freezer and in the case that the heating hot water or hot supply water is taken out, the heat source machine 2 is used as the single effective absorption heat pump.