Vehicle air conditioning apparatus

A vehicle air conditioning apparatus comprising:

• a compressor configured to compress and discharge a refrigerant;
• a radiator configured to release heat from the refrigerant;
• a heat exchanger configured to absorb the heat into the refrigerant;
• an outdoor heat exchanger configured to release the heat from or absorb the heat into the refrigerant;
• an outdoor radiator configured to further release the heat from the refrigerant having released the heat in the outdoor heat exchanger;
• a first operable mode comprising a cooling and/or cooling and dehumidifying refrigerant circuit configured to allow the refrigerant discharged from the compressor to flow into the radiator, to allow the refrigerant having passed through the radiator to flow into the outdoor heat exchanger, to allow the refrigerant having passed through the outdoor heat exchanger to flow into the outdoor radiator, to allow the refrigerant having passed through the outdoor radiator to flow into the heat exchanger via an expansion valve and to allow the refrigerant having passed through the heat exchanger to be sucked into the compressor;
• a second operable mode comprising a heating refrigerant circuit configured to allow the refrigerant discharged from the compressor to flow into the radiator, to allow the refrigerant having passed through the radiator to flow into the outdoor heat exchanger via an expansion part, and to allow the refrigerant having passed through the outdoor heat exchanger to be sucked into the compressor;
• a third operable mode comprising a first heating and dehumidifying refrigerant circuit configured to allow the refrigerant discharged from the compressor to flow into the radiator, to allow part of the refrigerant having passed through the radiator to flow into the outdoor heat exchanger via the expansion part, to allow remaining refrigerant having passed through the radiator to flow into the outdoor radiator, to allow the refrigerant having passed through the outdoor radiator to flow into the heat exchanger via the expansion valve, and to allow the refrigerant having passed through the outdoor heat exchanger and the refrigerant having passed though the heat exchanger to be sucked into the compressor;
• a fourth operable mode comprising a second heating and dehumidifying refrigerant circuit configured to allow the refrigerant discharged from the compressor to flow into the radiator, to allow the refrigerant having passed through the radiator to flow into the outdoor radiator, to allow the refrigerant having passed through the outdoor radiator to flow into the heat exchanger via the expansion valve, and to allow the refrigerant having passed through the heat exchanger to be sucked into the compressor;
• an air flow passage configured to allow air to be supplied to a vehicle interior to pass through, the heat exchanger being disposed in an upstream side of an air flow direction of the air flow passage, and the radiator being disposed downstream from the heat exchanger;
• an outlet switching part configured to switch modes among:
• a vent mode to blow the air flowing through the air flow passage toward a head of a passenger in the vehicle interior, a foot mode to blow the air toward feet of the passenger in the vehicle interior, and a bi-level mode to blow the air toward the head and the feet of the passenger in the vehicle interior, based on a target air-blowing temperature of the air to be supplied to the vehicle interior in order to set the temperature of the vehicle interior to a target preset temperature;
• an intake air temperature detector configured to detect a temperature of the air flowing into the air flow passage;
• and
• a heating and dehumidifying controller configured to start or stop an operation for the second heating and dehumidifying refrigerant circuit, based on the temperature detected by the intake air temperature detector, when the outlet switching part sets the bi-level mode.