refrigerant heat exchanger 6 is channelled into the small circuit 1 of the glycol circuit parallel to the heating heat exchanger 3 in the coolant circuit the glycol water mixture is moved by a pump 7 the glycol water mixture passes through the cooling system of the engine 16 and absorbs waste heat of the engine within a thermostat valve 4 the coolant is passed into the small circuit 1 and or the big circuit 2 in the small circuit 1 the coolant flows to a multi way directional valve 8 where the coolant flow is divided flowing in parallel through the glycol refrigerant heat exchanger 6 and the heating heat exchanger 3 in this way the multi way directional valve is adapted to enable both the parallel passage of the heating heat exchanger 3 and the glycol refrigerant heat exchanger 6 and the alternate single passage of the heat exchangers 3 6 the refrigerant is then again moved by the pump 7 through the engine 16 to absorb waste heat from the engine thus closing the circuit when the heating demand of the passenger compartment decreases the thermostat valve 4 provides the big circuit 2 with coolant in that measure as less heat is needed and the engine 39 s waste heat is dissipated through the radiator 5 to the environment dependent on the operational cycle different switching versions must be made possible by the coolant.