US Patent 6920922 Vehicle air conditioner with vapor-compression refrigerant cycle

An air conditioner includes a compressor for compressing refrigerant, an exterior heat exchanger for performing heat exchange between refrigerant and outside air, an interior heat exchanger for performing heat exchange between the refrigerant and air to be blown into the compartment, a decompression unit for decompressing high-pressure refrigerant, and a heater that heats air using high-temperature refrigerant discharged from the compressor as a heating source. In a dehumidifying and heating operation, refrigerant in the interior heat exchanger absorbs heat from air so that the air is cooled and dehumidified, and the heater heats air having been dehumidified and cooled by using the heating source, so that low-humidity and high-temperature air is supplied into the compartment. The heater can be disposed to indirectly heat air by heating a fluid flowing through a heater core for heating air, or to directly heat air to be blown into the compartment.