Air conditioner with heater priority mode and compressor priority mode

An air-conditioner comprising:

• a heat medium circuit including:
• a heating heat exchanger configured to exchange heat between a heat medium and a ventilation air to be blown to an air-conditioning target space;
• and
• an electric heater configured to heat the heat medium;
• a refrigerant cycle device configured to heat the heat medium in the heat medium circuit by exchanging heat between the heat medium and a high-temperature high-pressure refrigerant discharged from an electric compressor;
• a discharge capacity controlling section configured to control a rotational speed of the electric compressor;
• a heat generation amount controlling section configured to control a heating amount generated by the electric heater;
• a target temperature determining section configured to determine a target temperature of the heat medium to flow into the heating heat exchanger;
• and
• an upper limit determining section configured to determine an upper limit of the rotational speed of the electric compressor, wherein
• a difference calculated by subtracting a current temperature of the heat medium to be flown into the heating heat exchanger from the target temperature is defined as a temperature difference,
• a difference calculated by subtracting a current rotational speed of the electric compressor from the upper limit is defined as a capacity difference,
• the air conditioner is configured to selectively switch between a heater priority mode and a compressor priority mode,
• during the heater priority mode, the discharge capacity controlling section is configured to increase the rotational speed to reach the upper limit and the heat generation amount controlling section is configured to increase the heating amount as the temperature difference increases, and
• during the compressor priority mode, the heat generation amount controlling section is configured to decrease the heating amount generated by the electric heater by a decreasing amount and the discharge capacity controlling section is configured to increase the rotational speed of the electric compressor to compensate for the decreasing amount decreased by the heat generation amount controlling section.