Patent ID: 7458226

Claim:
An air conditioning system comprising: a compressor which compresses a refrigerant made of carbon dioxide, a radiator which radiates heat of the refrigerant compressed by the compressor, a pressure reducing unit which decompresses the refrigerant which had heat dissipated by the radiator and which can control a refrigerant pressure on an outlet side of the radiator, an evaporator which evaporates the refrigerant decompressed by the pressure reducing unit, a sensor which detects a temperature of a surface of a pipe through which a high pressure refrigerant on the outlet side of the radiator passes, and a control apparatus which calculates a target refrigerant pressure on the outlet side of the radiator based on a value detected by the sensor to control the pressure reducing unit, wherein the control apparatus corrects the target refrigerant pressure on the outlet side of the radiator based on a temperature of refrigerant discharged from the compressor.