is a rotary compressor such as a rolling piston rotary compressor a rotary vane type compressor or the like that is designed to compress the refrigerant gas at the pressure ratio efficiently the discharge side of the compressor 41 is connected by tubing 45 with a desuperheater 47 the desuperheater 47 may be omitted if desired but it improves the economics in that it saves the cost of heating water for domestic hot water or the like basically the desuperheater is a heat exchanger in which the hot refrigerant gas is passed interiorly of the coils on one side and the hot water is passed on the other side the discharge side of the desuperheater is connected via line 49 with a reversing valve 51 the reversing valve 51 is simply a solenoid operated valve in which a plunger directs the refrigerant to one of two paths depending upon whether it is in the cooling or heating mode a typical reversing valve is illustrated and described in a co pending application ser no 125 503 filed feb 28 1980 entitled 34 multiple source heat pump 34 amir l ecker assigned to the assignee of this application and the descriptive matter of that patent application is incorporated herein by reference for details that are omitted herefrom specifically in the heating mode the reversing valve is positioned so that the refrigerant in the form of a hot compressed gas flows into line 53 conversely in the cooling mode the reversing valve is positioned so that the hot compressed refrigerant flows into.