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.

An apparatus for a vehicle includes a cooling fan installed in an engine compartment of the vehicle. A fan motor is connected with the cooling fan to drive the cooling fan. A state detector is configured to detect state data, and a controller is configured to control the cooling fan based on the state data when an intake temperature is within a predetermined range, to determine whether the state data satisfies a decision reference condition, and to lock the fan motor according to a change rate of air conditioner refrigerant pressure during a measurement time when the state data satisfies the decision reference condition.

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.

Methods and systems are provided for controlling coolant flow through parallel branches of a coolant circuit including an AC condenser and a charge air cooler. Flow is apportioned responsive to an AC head pressure and a CAC temperature to reduce parasitic losses and improve fuel economy. The flow is apportioned via adjustments to a coolant pump output and a proportioning valve.

Methods and systems are provided for controlling coolant flow through parallel branches of a coolant circuit including an AC condenser and a charge air cooler. Flow is apportioned responsive to an AC head pressure and a CAC temperature to reduce parasitic losses and improve fuel economy. The flow is apportioned via adjustments to a coolant pump output and a proportioning valve.

A control device for a vehicle has a compressor for an air-conditioning device that is driven by a vehicle drive source, and a condenser for the air-conditioning device that is disposed at a front side of the vehicle. A request torque to the vehicle drive source is determined as a sum of an air-conditioning load which is spent for driving the compressor and a running torque necessary to drive the vehicle by a drive wheel. The running torque is calculated based on an accelerator manipulation of a driver. A range-position signal indicating a selected range position is read. A value of the air-conditioning load when the air-conditioning device is in operation and the range position is in a Reverse-range is larger than a value of the air-conditioning load when the range position is in a Drive-range with respect to an identical refrigerant pressure of the air-conditioning device.

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.

In a vehicle air conditioning apparatus, during a cooling operation, and a cooling and dehumidifying operation, a refrigerant flows through an outdoor heat exchanger, flows through a supercooling radiator, and then flows into a radiator to absorb heat. During a heating operation, the refrigerant flows through a heat exchanger and then is sucked into a compressor without passing through the supercooling radiator. During a first heating and dehumidifying operation, the refrigerant flows through another radiator, flows through the supercooling radiator, and then flows into another heat exchanger to absorb heat.

Method of cooling a heat exchanger of an engine using a cooling fan system includes: measuring conditions of an engine cooling system, determining a desired fan cooling demand. Based on the fan cooling demand, a fan control circuit operates to selectively control an electrically commutated (EC) motor at a continuously variable speed for an EC cooling fan and to control a direct current (DC) motor of a DC cooling fan. The DC motor is controlled to: not operate the DC cooling fan, operate the DC motor at a first predetermined operating speed, and operate the DC motor at a second predetermined operating speed corresponding to a second DC motor speed signal that is less than the first predetermined operating speed. The conditions for determining fan cooling demand include at least one of a temperature and a pressure of an engine coolant and of a refrigerant of a vehicle air conditioning system.