A vehicle air conditioning apparatus is provided that can prevent temperature variations of the air after the heat exchange in a radiator to reliably control the temperature of the air supplied to the vehicle interior. During the heating operation and the heating and dehumidifying operation, target degree of supercooling SCt when target air-blowing temperature TAO is a predetermined temperature or higher is set to SCt1 that is greater than SCt2 when the target air-blowing temperature TAO is lower than the predetermined temperature. When amount of air Ga supplied from indoor fan 12 is lower than a predetermined value, the target degree of supercooling SCt is corrected, which is set such that the degree of supercooling is lower than target degree of supercooling corrected when the amount of air Ga supplied from the indoor fan 12 is a predetermined value or higher.

Methods and systems are provided for controlling an air conditioning compressor clutch. In one example, a method includes monitoring a clutch of an air conditioning system in a vehicle when the air conditioning system is activated, and responsive to determining that the clutch is not engaged, increasing a current flow to the clutch. In this way, engagement of the compressor clutch may be dynamically maintained with a reduced usage of electrical power.

A cooling system includes a compressor that compresses a refrigerant, a heat exchanger that cools the refrigerant from the compressor, heat exchangers that use the refrigerant cooled by the heat exchanger, a refrigerant passage that supplies the refrigerant from the heat exchangers to a battery, a refrigerant passage that supplies the refrigerant cooled by the heat exchanger to the refrigerant passage without passing the refrigerant through the heat exchangers an expansion valve provided on the refrigerant passage, and a flow control valve provided on the refrigerant passage, and a processing circuitry increases the opening degree of the flow control valve when the specific enthalpy of the refrigerant supplied to the battery exceeds a predetermine range and reduces the opening degree of the flow control valve when the specific enthalpy is below the predetermined range.