An air conditioner and a method for controlling an air conditioner are provided. The air conditioner may include at least one indoor device, an electric heat pump (EHP) outdoor device connected to the at least one indoor device and having an EHP compressor driven using an applied current, and a gas heat pump (GHP) outdoor device connected to the at least one indoor device having an engine driven using a combustion of gas and a GHP compressor driven by receiving a driving force from the engine. The EHP compressor may include an inverter that controls a frequency of the current applied to the EHP compressor. The GHP compressor may include a first compressor that receives a driving force from the engine to compress a refrigerant; and a second compressor that is connected to the first compressor in parallel and receives the driving force from the engine to compress the refrigerant.

A determination device includes a refrigerant circuit, an operation determination unit, and a refrigerant determination unit. The refrigerant circuit is made of a compressor, a condenser, an expansion mechanism, and an evaporator that are circularly connected. In a refrigeration cycle operation in accordance with a quantity of heat required by the condensers or the evaporators, the operation determination unit determines whether the refrigeration cycle operation can be normally carried out or not. Upon determination that the refrigeration cycle operation cannot be normally carried out, the refrigerant determination unit determines whether a refrigerant in the refrigerant circuit is regenerable or not, based on a result of the determination. Thus the determination device is provided by which an effort involved with determination as to whether the refrigerant is regenerable or not can be reduced.

An HVAC system includes an outdoor heat exchanger. A first indoor heat exchanger is fluidly coupled to the outdoor heat exchanger and disposed in a first zone. A second indoor heat exchanger is fluidly coupled to the outdoor heat exchanger and disposed in a second zone. A compressor is fluidly coupled to the outdoor heat exchanger, the first indoor heat exchanger, and the second indoor heat exchanger. A first zone controller is electrically coupled to the first indoor heat exchanger. The first zone controller is configured to measure a temperature in the first zone, compare the measured temperature to a setpoint temperature of the first zone, and responsive to a difference between the measured temperature and the setpoint temperature, adjust a speed of a first circulation fan independent of the speed of a second circulation fan.

A condenser includes: a first heat exchange portion and a second heat exchange portion that are configured such that refrigerant in the first heat exchange portion flows in parallel with refrigerant in the second heat exchange portion; a flow rate restricting portion configured to cause a flow rate difference between a flow rate of the refrigerant passing through the first heat exchange portion and a flow rate of the refrigerant passing through the second heat exchange portion. An air conditioner includes a controller configured to control a compressor and a flow rate restricting portion. When the controller changes an air conditioning capability of the air conditioner, the controller uses a combination of a frequency of the compressor and the flow rate difference between the refrigerants passing through two heat exchange portions.

Heat pump system (100) comprising at least one heat medium circuit (210,220,230,240,250,310,320,410,420,430,440,450,460) in turn comprising a compressor (211), an expansion valve (232,242), at least two different primary heat sources or sinks selected from outdoor air, a water body, the ground or exhaust air, at least one of two different secondary heat sources or sinks selected from indoors air, pool water and tap water, a respective temperature sensor (412,432) at each of said primary heat sources or sinks, a valve means (421,431,451) for selectively directing the primary-side heat medium to at least one of said primary heat exchanging means, and a control means (500). The invention is characterised in that, in a secondary-side heating operating mode, the temperature of said primary heat sources or sinksis measured, and in that the primary-side heat medium is directed only to the primary heat exchanging means associated with the heat sources or sinks with the highest temperature. The invention also relates to a method.

An air-conditioning device including multiple outdoor units and an indoor unit through a pipe includes a control section that obtains a degree of subcooling at an outlet of a subcooling circuit of each outdoor unit based on a temperature detected by a temperature sensor that detects the temperature of refrigerant having passed through the subcooling circuit of each outdoor unit, obtain a target value of the degree of subcooling based on the obtained multiple degrees of subcooling, and perform the control of increasing the rotation speed of a compressor of an outdoor unit having a higher degree of subcooling than the target value and decreasing the rotation speed of a compressor of an outdoor unit having a lower degree of subcooling than the target value such that a difference in the degree of subcooling at the outlet of the subcooling circuit of each outdoor unit is decreased.

Provided are a heat sink capable of suppressing overcooling of an electronic component which should not be overcooled and highly efficiently cooling only an electronic component which should be cooled, and a circuit device including the same. A heat sink includes a pipe and a cooling block. At least one projection is formed in the cooling block. The pipe is in contact with the projection. The pipe is arranged with a spacing from a portion of the cooling block other than the projection.

A refrigerant flow path switching device includes: a first header pipe that is connected to a high-and-low-pressure gas connection pipe of a heat source unit in an air conditioner; a second header pipe that is connected to a sucked-gas connection pipe of the heat source unit; a third header pipe that is connected to a liquid connection pipe of the heat source unit; switching units that each correspond respectively to utilization units in the air conditioner and include valves that control refrigerant flows; and a casing accommodating the first header pipe, the second header pipe, the third header pipe, and switching units. The refrigerant flow path switching device switches among refrigerant flow paths, each of which is between the heat source unit and one of the utilization units.

An air-conditioning apparatus includes a refrigerant circuit in which a compressor, a refrigerant flow switching device, a heat source side heat exchanger, an expansion device, a heat medium heat exchanger, and an accumulator are connected, a heat medium circuit in which a pump, the heat medium heat exchanger, a heat medium flow control device, and a load side heat exchanger are connected, at least one or more bypass pipes provided in the refrigerant circuit so that the refrigerant discharged from the compressor bypasses at least either one of the heat source side heat exchanger and the heat medium heat exchanger, a bypass opening and closing device provided at the bypass pipe, and a controller configured to control the bypass opening and closing device to carry out a start-up control function of causing low-pressure gas refrigerant with a high degree of superheat to flow into the accumulator.

An air conditioner of an embodiment includes a plurality of outdoor units, one or more indoor units, and a control unit. The outdoor unit includes a compressor, a four-way valve, an outdoor heat exchanger, an outdoor expansion valve and an outdoor blower, and the outdoor units exchange heat between the outside air and a refrigerant. The indoor unit is an indoor unit connected to the plurality of outdoor units by a refrigerant pipe, includes an indoor heat exchanger, an indoor expansion valve, and an indoor blower, and exchanges heat between the indoor air and the refrigerant. The control unit controls the plurality of outdoor units and the one or more indoor units. The control unit controls the condensation pressure of the outdoor unit in a heating operation or the suction pressure of the outdoor unit in a defrosting operation to be equal to or smaller than an upper limit pressure, which is 1/1.5 times the rated maximum pressure during the heating operation when any of the outdoor units is in the defrosting operation.