AIR CONDITIONER

PROBLEM TO BE SOLVED: To provide an air conditioner capable of further shortening an engine warm-up operation time without increasing the number of components. SOLUTION: An outdoor unit 10 includes an engine exhaust heat exchanger 16 provided in a cooling fluid circuit L in which a cooling fluid is circulated and functioning as a refrigerant evaporator during heating operation. During the heating operation, a control device 41 performs the warm-up operation of a gas engine 11 at a rotating speed in a predetermined range including a predetermined maximum based on a heating capacity when the temperature of the cooling fluid is lower than a predetermined target temperature, and operates the gas engine 11 at a rotating speed corresponding to air-conditioning loads of all indoor units when the temperature of the cooling fluid exceeds the predetermined temperature. The air conditioner includes a hot gas valve 17 of which the opening/closing is controlled so as to make a discharge pipe 12b communicate with a suction pipe 12a when the refrigerant pressure of the discharge pipe 12b of a compressor 12 exceeds high side predetermined pressure during the warm-up operation of the gas engine 11, or when the refrigerant pressure of the suction pipe 12a of the compressor 12 falls below low side predetermined pressure. COPYRIGHT: (C)2011,JPO&INPIT