Methods and systems are provided for controlling an air conditioning system of a motor vehicle. In one example, a cabin of the vehicle may be heated firstly to a first temperature by flowing coolant to a heat exchanger, coolant may be diverted away from the heat exchanger and toward the engine in order to increase a temperature of the engine, and the coolant may then flow again to the heat exchanger in order to heat the cabin to a second temperature. An amount of fuel savings resulting from heating the engine by diverting coolant away from the heat exchanger may be displayed to an operator of the vehicle via a display device.

Methods and systems are provided for controlling an air conditioning system of a motor vehicle. In one example, a cabin of the vehicle may be heated firstly to a first temperature by flowing coolant to a heat exchanger, coolant may be diverted away from the heat exchanger and toward the engine in order to increase a temperature of the engine, and the coolant may then flow again to the heat exchanger in order to heat the cabin to a second temperature. An amount of fuel savings resulting from heating the engine by diverting coolant away from the heat exchanger may be displayed to an operator of the vehicle via a display device.

An engine cooling device for a vehicle of the present invention includes: an engine cooling circuit that circulates a cooling liquid to an engine and a heat exchanger; a reservoir tank that is connected to the engine cooling circuit, and that stores the cooling liquid to absorb pressure changes within the engine cooling circuit; at least one or more cooling liquid circulating circuits that circulates the cooling liquid to devices installed in the vehicle; a switching section that selectively switches between either of a communicating state of communicating the engine cooling circuit and the cooling liquid circulating circuit, and a cut-off state of cutting-off the engine cooling circuit and the cooling liquid circulating circuit; and a control section that, in a case in which an ignition switch is turned off, controls the switching section such that the communicating state is set.

A first heat transfer medium circuit includes a first path and a second heat transfer medium circuit includes a second path are formed independently from each other by operating a first switching valve and a second switching valve in conjunction with each other to make each of multiple flow passages of a first flow passage group communicate with either the first path or the second path. The first and second heat transfer medium circuits in which the first path and the second path are connected to each other in series is formed by operating the first switching valve and the second switching valve in conjunction with each other to make each of the multiple flow passages of the first flow passage group communicate with both the first path and the second path.

A first heat transfer medium circuit includes a first path and a second heat transfer medium circuit includes a second path are formed independently from each other by operating a first switching valve and a second switching valve in conjunction with each other to make each of multiple flow passages of a first flow passage group communicate with either the first path or the second path. The first and second heat transfer medium circuits in which the first path and the second path are connected to each other in series is formed by operating the first switching valve and the second switching valve in conjunction with each other to make each of the multiple flow passages of the first flow passage group communicate with both the first path and the second path.

A vehicle includes a heating, ventilation and air conditioning (HVAC) system for heating and cooling a passenger compartment. The HVAC system includes a refrigerant loop and a coolant loop, and an auxiliary coolant loop for heating and cooling at least a portion of the passenger compartment. The auxiliary coolant loop includes a pump for moving a coolant, within the auxiliary coolant loop, through a first heat exchanger coupled to the refrigerant loop via an expansion device, a second heat exchanger positioned within the passenger compartment, and a third heat exchanger coupled to the coolant loop. A flow control valve controls a flow of coolant to the third heat exchanger. The temperature of the coolant within the auxiliary coolant loop is controlled utilizing the flow valve and the pump. The first and third heat exchangers may be in parallel for controlling the movement of coolant there between to control temperature.

A vehicle includes a heating, ventilation and air conditioning (HVAC) system for heating and cooling a passenger compartment. The HVAC system includes a refrigerant loop and a coolant loop, and an auxiliary coolant loop for heating and cooling at least a portion of the passenger compartment. The auxiliary coolant loop includes a pump for moving a coolant, within the auxiliary coolant loop, through a first heat exchanger coupled to the refrigerant loop via an expansion device, a second heat exchanger positioned within the passenger compartment, and a third heat exchanger coupled to the coolant loop. A flow control valve controls a flow of coolant to the third heat exchanger. The temperature of the coolant within the auxiliary coolant loop is controlled utilizing the flow valve and the pump. The first and third heat exchangers may be in parallel for controlling the movement of coolant there between to control temperature.

A vehicle includes a heating, ventilation and air conditioning (HVAC) system for heating and cooling a passenger compartment. The HVAC system includes a refrigerant loop operable in a cooling mode and a heating mode, and an auxiliary coolant loop for heating and cooling at least a portion of the passenger compartment. The auxiliary coolant loop includes a pump for moving a coolant, within the auxiliary coolant loop, through a first heat exchanger coupled to the refrigerant loop via an expansion device in the cooling mode, a second heat exchanger positioned within the passenger compartment, and a third heat exchanger coupled to the refrigerant loop, and a flow control valve. The temperature of the coolant within the auxiliary coolant loop is controlled utilizing the flow control valve and the pump. The first and third heat exchangers may be in parallel for controlling the movement of coolant therebetween to control temperature.

A vehicular air conditioning system having an air inlet and an air outlet includes a first heating heat exchanger configured to heat air introduced through the air inlet, a second heating heat exchanger configured to heat air passing through the first heating heat exchanger or bypassing the first heating heat exchanger, and a control part configured to control the first heating heat exchanger and the second heating heat exchanger according to a passenger room heating load so that when the heating load decreases to below a preset value in a heating mode in which the first heating heat exchanger and the second heating heat exchanger are operated simultaneously, the first heating heat exchanger is first turned off and only the second heating heat exchanger is operated.

A thermal management system for a vehicle including an engine and a transmission can include a radiator, first and second heat exchangers, a control valve and a bypass valve. The radiator can be configured for fluid communication with the engine. The first heat exchanger can be configured for fluid communication with the transmission. The control valve can be configured to selectively communicate a source of relative warm engine fluid or a source of relative cool engine fluid to the first heat exchanger in order to warm or cool the transmission fluid, respectively. The second heat exchanger can be configured to exchanger heat between the transmission fluid and the ambient fluid external to the passenger compartment of the vehicle. The by-pass valve can be configured to selectively direct transmission fluid into or to by-pass the second heat exchanger.