Air-conditioning system with air-conditioning and heat-pump mode

An air-conditioning system which is suitable for a motor vehicle and which is capable of operating at least in an air-conditioning mode for cooling a thermal control medium and in a heat-pump mode for heating the thermal control medium, comprising:

• a coolant circuit comprising a heat-generating unit to be cooled and a heater for heating the thermal control medium;
• a refrigerant circuit comprising a compressor and an evaporator, wherein the evaporator comprises a first refrigerant/coolant heat exchanger that interrelates the coolant circuit and the refrigeration circuit;
• a first refrigerant cooler comprising a second refrigerant/coolant heat exchanger interrelating said refrigerant circuit and said coolant circuit and functioning on the refrigerant side as a condenser/gas cooler;
• a cooler in said coolant circuit downstream of the evaporator for selectively cooling the thermal control medium on its coolant side, and
• a coolant flow controller means for selectively performing each of the functions of (a) transferring coolant from the heater directly to the evaporator while simultaneously transferring the coolant from the cooler to the heat-generating unit, and (b) transferring coolant from the heater to the heat generating unit while simultaneously transferring coolant from the cooler to the evaporator.