Vehicular air conditioner

A vehicular air conditioner, comprising:

• an air conditioning duct through which conditioning air for a passenger compartment of a vehicle flows;
• a heater core disposed in the air conditioning duct, coolant for cooling an engine of the vehicle flowing through the heater core;
• a heat pump cycle unit including
• a first inside heat exchanger disposed downstream of the heater core in a flow direction of the conditioning air, the first inside heat exchanger being configured to exchange heat between the conditioning air and a refrigerant,
• a second inside heat exchanger disposed upstream of the heater core in the flow direction of the conditioning air, the second inside heat exchanger being configured to exchange heat between the conditioning air and the refrigerant, and
• an outside heat exchanger configured to exchange heat between air outside the vehicle and the refrigerant;
• a temperature detector configured to detect a passage air temperature, the passage air temperature being a temperature of the conditioning air that has passed through the heater core;
• a controller configured to control the heat pump cycle unit;
• and
• an outside air temperature sensor configured to detect an outside air temperature that is a temperature outside the vehicle, wherein
• the controller is configured to:
• selectively switch a circuit layout of the heat pump cycle unit between a cooling circuit, a heating circuit, and a dehumidifying-heating circuit based on the passage air temperature;
• switch the layout of the heat pump cycle unit to the cooling circuit by allowing the refrigerant to flow through the first inside heat exchanger, the second inside heat exchanger serving as an evaporator, and the outside heat exchanger serving as a condenser;
• switch the layout of the heat pump cycle unit to the heating circuit by allowing the refrigerant to flow through the first inside heat exchanger serving as a condenser, and the outside heat exchanger serving as an evaporator;
• switch the layout of the heat pump cycle unit to the dehumidifying-heating circuit by allowing the refrigerant to flow through the first inside heat exchanger serving as a condenser, the second inside heat exchanger serving as an evaporator, and the outside heat exchanger;
• control the heat pump cycle unit such that an outlet temperature of the conditioning air to be blown into the passenger compartment reaches a target outlet temperature;
• execute a first processing, when the passage air temperature is equal to or less than the target outlet temperature, by
• (i) switching the layout of the heat pump cycle unit to the dehumidifying-heating circuit when the outside air temperature is higher than a first temperature threshold value, and
• (ii) switching the layout of the heat pump cycle unit to the heating circuit when the outside air temperature is equal to or less than the first temperature threshold value;
• and
• execute a second processing, when the passage air temperature is higher than the target outlet temperature, by switching the layout of the heat pump cycle unit to the cooling circuit when the outside air temperature is higher than a second temperature threshold value, wherein
• the second temperature threshold value is less than the first temperature threshold value, and
• the vehicle has a drive mode selectively settable to an HV mode and an EV mode, the vehicle being driven by power from the engine in the HV mode, the vehicle being driven by power from an electric motor in the EV mode.