AIR CONDITIONER FOR VEHICLE

PROBLEM TO BE SOLVED: To quickly obtain sufficient heating capability at the time of dehumidifying and heating operation by providing a means for judging insufficient heat radiation of a subcondenser and providing a means for increasing load of a compressor when it is judged that heat radiation is insufficient at the time of dehumidifying and heating operation. SOLUTION: In a cooling cycle, a pressure sensor 55 for detecting low pressure of a compressor is provided, and a second solenoid valve V2 is provided in a passage part 62 communicating a discharge side of the compressor 50 with a subcondenser 16. At the time of dehumidifying and heating operation, when low pressure detected by the pressure sensor 55 is below a predetermined value, it is judged that a heat radiation amount in the subcondenser 16 is low, and the second solenoid valve V2 is opened and closed at a predetermined cycle to perform compressor power increase control so as to increase load of the compressor 50 abruptly. Consequently, since a heat radiation amount of the subcondenser 16 can be increased abruptly, it is possible to increase a heating amount up to a predetermined level quickly.