Patent ID: 7331189

Claim:
A cooling system composed of an outdoor unit comprising a compressor for supplying refrigerant under pressure and a condenser for cooling and condensing the refrigerant supplied from the compressor, and an indoor unit comprising a liquid receiver arranged to temporarily store the condensed refrigerant supplied from the condenser, an expansion valve for expanding the refrigerant supplied from the liquid receiver and an evaporator arranged to effect evaporation of the expanded refrigerant for cooling the surrounding thereof, wherein the indoor unit comprises a bypass conduit arranged to bypass the liquid receiver and expansion valve and flow passage changeover means electrically controlled to selectively connect a supply passage of refrigerant to the liquid receiver and expansion valve and to the bypass conduit so that the supply passage of refrigerant is connected to the liquid receiver and expansion valve during operation at a cooling mode and is connected to the bypass conduit during operation at a defrost mode, and wherein said flow passage changeover means is in the form of a three-way valve having an inlet port connected to the condenser, a first outlet port for connection to the liquid receiver, and a second outlet port for connection to the bypass conduit.