An air conditioning apparatus comprising a continuous circuit through which a refrigerant flows from a compressor, through a condenser, through a heat exchanger, through an evaporator, and returning to the compressor, a bypass circuit through which a portion of the refrigerant flows from a point upstream of the condenser to mix with the refrigerant at a point downstream of the condenser, and a discharge gas valve for controlling the portion of the refrigerant flowing through the bypass circuit.