VEHICULAR AIR CONDITIONER

A vehicular air conditioner includes a refrigeration cycle system, a high-temperature heat medium circuit, and a low-temperature heat medium circuit. The high-temperature heat medium circuit includes an air-heat medium heat exchanger, a heater core, a branching portion, a common passage, a flow rate adjuster, and an auxiliary heat source. The air-heat medium heat exchanger exchanges heat between the heat medium and an outside air. The heater core is arranged parallel to the air-heat medium heat exchanger and causes the heat medium to transfer heat to a ventilation air. The branching portion divides a flow of the heat medium into a flow toward the air-heat medium heat exchanger and a flow toward the heater core. The auxiliary heat source is arranged in the common passage at a position upstream of the branching portion.