A first sensor measures temperature at a first evaporator that cools a first zone. A second sensor measures temperature at a second evaporator that cools a second zone. A controller operates a compressor in a normal cooling mode or a single zone cooling mode. In the normal cooling mode, both the first zone and the second zone are cooled with the compressor operated by the controller in response to temperature measurements from one or both of the first sensor and the second sensor. In the single zone cooling mode, only the second zone is cooled with the compressor controlled by the controller in response to temperature measurements from the second sensor and the controller determining that the first evaporator has a low probability of accumulating frozen moisture on surfaces thereof, and in response to determining a high probability of accumulating frozen moisture on surfaces thereof the compressor is not operated.

A refrigeration cycle device includes: a first expansion valve that decompresses a refrigerant flowing out of a high-pressure side heat exchanger; an exterior heat exchanger that exchanges heat between the refrigerant flowing out of the first expansion valve and outside air; a second expansion valve that decompresses the refrigerant flowing out of the exterior heat exchanger; a low-pressure side heat exchanger arranged in series with the exterior heat exchanger; a cooler core that exchanges heat between the heat medium cooled by the low-pressure side heat exchanger and air to be blown into a vehicle interior to cool the air; and a controller configured to switch between a heat absorption mode and a heat dissipation mode by adjusting an amount of decompression in each of the first expansion valve and the second expansion valve.

A refrigeration cycle device includes: a high-pressure side heat exchanger; a low-pressure side heat exchanger; a vehicle-mounted device that supplies heat to the heat medium; a heat-medium air heat exchanger that exchanges heat between the heat medium and air; a switching portion that switches between a state in which the heat medium circulates through the high-pressure side heat exchanger and a state in which the heat medium circulates through the low-pressure side heat exchanger with respect to each of the vehicle-mounted device and the heat-medium air heat exchanger; and a controller that drives the compressor, while controlling an operation of the switching portion to switch to a defrosting mode in which the heat medium circulates between the low-pressure side heat exchanger and the vehicle-mounted device, and the heat medium circulates between the high-pressure side heat exchanger and the heat-medium air heat exchanger, when defrosting of the heat-medium air heat exchanger is necessary.

A control unit, at the time of a heating operation, pressure-reduces refrigerant that has passed through an indoor condenser, by an expansion valve, and thereafter introduces the refrigerant into an outdoor heat exchanger to thereby perform heat exchange with outside air. Further, the control unit, at the time of a defrosting operation, introduces high-temperature and high-pressure refrigerant compressed by a compressor into the outdoor heat exchanger to thereby remove frost adhering to the outdoor heat exchanger. Furthermore, the control unit determines whether to perform the defrosting operation or not, based on the amount of electric power required for the defrosting operation.

An air-conditioning system of a motor vehicle having refrigerant circulation and coolant circulation. Refrigerant circulation comprises a compressor, a refrigerant-coolant heat exchanger operable as condenser/gas cooler for heat transfer between the refrigerant and the coolant, a first expansion element and a first refrigerant-air heat exchanger for conditioning the inflowing air for the passenger compartment. Coolant circulation is developed with a conveying device, a first coolant-air heat exchanger for heating the inflowing air for the passenger compartment, a second coolant-air heat exchanger and the refrigerant-coolant heat exchanger. Refrigerant circulation also includes a second refrigerant-air heat exchanger, operable exclusively as evaporator. Upstream of the second refrigerant-air heat exchanger in the direction of flow of the refrigerant, a second expansion element is disposed. The second expansion element and the second refrigerant-air heat exchanger are disposed within a first flow path. A method for operating the air-conditioning system.

An air conditioning apparatus for a vehicle includes a refrigerant heater 41 that is provided between an internal evaporator 8 and a suction side of an electric compressor 20 to be in parallel with an external evaporator 32, and heats a refrigerant which is suctioned into the electric compressor 20; and an air conditioning control apparatus 50 that determines whether the external evaporator 32 is frosted. While the air conditioning apparatus for a vehicle operates in a heating mode, when the air conditioning control apparatus 50 determines that the external evaporator 32 is frosted, a supply of the refrigerant subject to the heat exchange in an internal condenser 9 to the external evaporator 32 is stopped, and the refrigerant is supplied to the refrigerant heater 41, is heated and then, is suctioned into the electric compressor 20.

The invention relates to an air conditioning device comprising a refrigerant circuit and a coolant circuit. The refrigerant circuit comprises at least a compressor, an internal heat exchanger, an external heat exchanger and an evaporator The coolant circuit comprises at least a first heat exchanger associated with a first component, a second heat exchanger associated with a second component and a radiator. A fluid/fluid heat exchanger is installed in the refrigerant circuit and in the coolant circuit, with the coolant circuit comprising a first loop and a second loop which are interconnected by an interconnection device. The first loop comprises the fluid/fluid heat exchanger, the first heat exchanger associated with the first component and a means for heating the coolant with the means interposed between the interconnection device and the fluid/fluid heat exchanger, the second loop comprising the second heat exchanger associated with the second component and the radiator.

Methods and systems are provided for adjusting operation of an automotive air conditioning system including a pressure sensor positioned within a compression chamber. In one example, a method may include adjusting operation of the air conditioning system based on one or more parameters of a compressor operation including a compressor inlet pressure, a compressor outlet pressure, and a compressor speed, that are determined based on output from the pressure sensor positioned within the compression chamber.

In a heat pump system, when a heat-shock determination portion determines that a difference between a coolant temperature in a coolant flow path and a coolant temperature in a heat source flow path is equal to or higher than a predetermined temperature, a flow-path switching portion mixes the respective coolants flowing through at least a bypass flow path and the heat source flow path together to flow into the coolant flow path.

If an exterior heat exchanger is sensed to be frosted while a heat pump device is operating in a first heating operation mode in which two interior heat exchangers are used, the operation modes are switched into a second heating operation mode in which one interior heat exchanger is used, and then switched into a defrosting operation mode.