Patent ID: 6892549

Claim:
An air conditioner for a vehicle having an engine for running the vehicle, the air conditioner comprising: a refrigerant cycle including a variable displacement compressor, driven at least by the engine, for compressing refrigerant, the compressor being capable of adjusting its displacement from an outside, and an evaporator for cooling air to be blown into a passenger compartment of the vehicle by performing a heat exchange between the air and low-pressure low-temperature refrigerant in the refrigerant cycle supplied by the compressor; and an air-conditioning control unit for controlling the displacement of the compressor based on a cooling load in the passenger compartment, wherein: the air-conditioning control unit outputs an engine drive signal for requiring a drive of the engine, and the compressor is driven by the engine, when the cooling load is larger than a predetermined value; the air-conditioning control unit prohibits an output of the engine drive signal when the cooling load is equal to or smaller than the predetermined value; and when the cooling load is larger than the predetermined value, the air-conditioning control unit controls the displacement of the compressor at a control value larger than a value controlled based on the cooling load, at least for a predetermined time.