When performing dehumidification heating of a space to be air-conditioned, a refrigeration cycle device is switched to a refrigerant circuit in which a flow of a refrigerant flowing out of an interior radiator is branched, and one of the branched refrigerants is decompressed by an interior expansion valve to evaporate in an interior evaporator, while the other of the branched refrigerants flows into a high-pressure side refrigerant passage of an internal heat exchanger and is then decompressed by an exterior expansion valve to evaporate in an exterior heat exchanger. Further, in the refrigerant circuit, a flow of the refrigerant flowing out of the interior evaporator and a flow of the refrigerant flowing out of the exterior heat exchanger are merged into a low-pressure side refrigerant passage of the internal heat exchanger. Thus, the refrigerant flowing into the interior evaporator is prevented from becoming a liquid-phase refrigerant having an unnecessarily high degree of supercooling, thereby achieving appropriate dehumidification heating.

A vehicle air conditioning apparatus is provided that can prevent temperature variations of the air after the heat exchange in a radiator to reliably control the temperature of the air supplied to the vehicle interior. During the heating operation and the heating and dehumidifying operation, target degree of supercooling SCt when target air-blowing temperature TAO is a predetermined temperature or higher is set to SCt1 that is greater than SCt2 when the target air-blowing temperature TAO is lower than the predetermined temperature. When amount of air Ga supplied from indoor fan 12 is lower than a predetermined value, the target degree of supercooling SCt is corrected, which is set such that the degree of supercooling is lower than target degree of supercooling corrected when the amount of air Ga supplied from the indoor fan 12 is a predetermined value or higher.

Systems and method relate to a fuel efficient automatic temperature control system. The system includes a climate control system configured to heat or cool air. The climate control system includes a condenser and a variable-speed fan. A first sensor provides vent-air information indicative of a condition of the air. An automatic temperature controller receives an indication of a desired temperature, receives the vent-air information, determines whether the variable-speed fan should operate at a maximum fan speed based on at least the desired temperature and the vent-air information and determines whether a dehumidifying operation is requested. If the variable-speed fan is required to operate at the maximum fan speed or a dehumidifying operation is requested, the fan operates at the maximum speed. If the variable-speed fan is not required to operate at the maximum fan speed and a dehumidifying operation is not requested, the fan operates below the maximum fan speed.

A vehicle air conditioning apparatus is provided that can prevent temperature variations of the air after the heat exchange in a radiator to reliably control the temperature of the air supplied to the vehicle interior. During the heating operation and the heating and dehumidifying operation, target degree of supercooling SCt when target air-blowing temperature TAO is a predetermined temperature or higher is set to SCt1 that is greater than SCt2 when the target air-blowing temperature TAO is lower than the predetermined temperature. When amount of air Ga supplied from indoor fan 12 is lower than a predetermined value, the target degree of supercooling SCt is corrected, which is set such that the degree of supercooling is lower than target degree of supercooling corrected when the amount of air Ga supplied from the indoor fan 12 is a predetermined value or higher.

A vehicle air conditioning apparatus is provided that can prevent temperature variations of the air after the heat exchange in a radiator to reliably control the temperature of the air supplied to the vehicle interior. During the heating operation and the heating and dehumidifying operation, target degree of supercooling SCt when target air-blowing temperature TAO is a predetermined temperature or higher is set to SCt1 that is greater than SCt2 when the target air-blowing temperature TAO is lower than the predetermined temperature. When amount of air Ga supplied from indoor fan 12 is lower than a predetermined value, the target degree of supercooling SCt is corrected, which is set such that the degree of supercooling is lower than target degree of supercooling corrected when the amount of air Ga supplied from the indoor fan 12 is a predetermined value or higher.

A vehicle air conditioning apparatus is provided that can prevent temperature variations of the air after the heat exchange in a radiator to reliably control the temperature of the air supplied to the vehicle interior. During the heating operation and the heating and dehumidifying operation, target degree of supercooling SCt when target air-blowing temperature TAO is a predetermined temperature or higher is set to SCt1 that is greater than SCt2 when the target air-blowing temperature TAO is lower than the predetermined temperature. When amount of air Ga supplied from indoor fan 12 is lower than a predetermined value, the target degree of supercooling SCt is corrected, which is set such that the degree of supercooling is lower than target degree of supercooling corrected when the amount of air Ga supplied from the indoor fan 12 is a predetermined value or higher.