Vehicle air conditioner with ejector refrigerant cycle

An air conditioner for a compartment, comprising:

• a compressor for compressing and discharging refrigerant;
• an exterior heat exchanger for performing heat exchange between refrigerant and outside air outside the compartment;
• an interior heat exchanger for performing heat exchange between refrigerant and air to be blown into the compartment;
• an ejector for decompressing refrigerant discharged from the compressor while sucking gas refrigerant from one of the interior heat exchanger and exterior heat exchanger, and for converting expansion energy to pressure energy to increase pressure of refrigerant to be sucked to the compressor;
• a heater core disposed for heating air to be blown into the compartment by using a fluid flowing therein as a heating source;
• and
• a fluid-refrigerant heat exchanger disposed to perform heat exchange between refrigerant discharged from the compressor and the fluid to be supplied to the heater core, wherein:
• when refrigerant is evaporated in the interior heat exchanger to cool air passing through the interior heat exchanger, refrigerant is decompressed in the ejector.