An air conditioner system including a compressor, a condenser, an expander, an evaporator, and a bypass pipeline that guides the evaporated refrigerant from the evaporator to the condenser, wherein the bypass pipeline includes: a first bypass pipe configured to guide at least some of the evaporated refrigerant from the evaporator to the condenser; a second bypass pipe attached to the first bypass pipe to allow heat exchange between refrigerant in the condenser and refrigerant therein; and a third bypass pipe coupled to the second bypass pipe to guide the refrigerant from the second bypass pipe out of the condenser.

An aggregated channel switching unit is disposed between a heat source unit and a plurality of utilization units to switch flow of refrigerant in the refrigerant circuit. The aggregated channel switching unit including a plurality of first refrigerant pipes having switch valves, a plurality of second refrigerant pipes, and a casing accommodating the first and second pipes. The first and second pipes are aggregated as an assembly. The first pipes are connected to a high-low pressure gas communicating pipe and a suction gas communicating pipe extending from the heat source unit. The second refrigerant pipes are connected to a liquid communicating pipe extending from the heat source unit and a liquid pipe extending to the utilization units. Adjacent pairs of the first and second pipes extend approximately in parallel to each other at predetermined intervals in the assembly. The first and second pipes are alternately disposed in the assembly.

An air-conditioning apparatus includes two heat source units, each including a compressor, an outdoor heat exchanger functioning as an evaporator, an accumulator connected to a suction side of the compressor, and at least one of an outdoor air-sending device configured to supply air corresponding to a heat exchange target for refrigerant to the outdoor heat exchanger or a flow control device (bypass and expansion device for bypass) configured to regulate a flow rate of the refrigerant flowing through the outdoor heat exchanger. A controller is configured to control at least one of the outdoor air-sending device or the flow control device so that a suction quality of the compressor of an upper heat source unit installed on an upper side and a suction quality of the compressor of a lower heat source unit installed on a lower side become the same.

An air conditioner operable even in a low-load cooling or heating mode is provided. The air conditioner may include a compressor that compresses a refrigerant, a main outdoor heat exchanger that condenses the refrigerant in a cooling mode and that evaporates the refrigerant in a heating mode, an indoor heat exchanger that evaporates the refrigerant in the cooling mode while condensing the refrigerant in the heating mode, a switch that guides the refrigerant discharged from the compressor to the main outdoor heat exchanger in the cooling mode and that guides the refrigerant discharged from the compressor to the indoor heat exchanger in the heating mode, and a sub outdoor heat exchanger that evaporates a portion of the refrigerant condensed in the main outdoor heat exchanger in a low-load cooling mode and that condenses a portion of the refrigerant discharged from the compressor in a low-load heating mode.

An air conditioning system according to the present invention changes a target supply temperature based on a magnitude relationship between an operating frequency of a first compressor and a first frequency at which an operating efficiency of the first compressor reaches a maximum, and a magnitude relationship between an operating frequency of a second compressor and a second frequency at which an operating efficiency of the second compressor reaches a maximum.

A refrigerating device that forms a refrigerating cycle in which a plurality of outdoor machines 1a and 1b provided at least with compressors 2a and 2b, condensers 4a and 4b, and accumulators 5a and 5b respectively and an indoor machine 20 provided with decompressing means 21 and an evaporator 22 are connected in parallel by piping, having oil return pipes 13a and 13b that return refrigerator oil stored in the accumulators into the compressors, an oil equalizing pipe 10 that connects the accumulators to each other, and a controller 30 that controls an operation of the compressor and on/off of an electromagnetic valve 12a deposed on the oil equalizing pipe.

An air conditioner includes an outdoor unit in which refrigerant circulates; an indoor unit in which water circulates; a heat exchange device including a heat exchanger connecting the outdoor unit to the indoor unit and performing heat exchange between the refrigerant and the water; a first outdoor unit connection pipe connecting the outdoor unit and the heat exchange device, a high-pressure gaseous refrigerant flowing in the first outdoor unit connection pipe; a second outdoor unit connection pipe connecting the outdoor unit and the heat exchange device, a low-pressure gaseous refrigerant flowing in the second outdoor unit connection pipe; a third outdoor unit connection pipe connecting the outdoor unit and the heat exchange device, a liquid refrigerant flowing in the third outdoor unit connection pipe; a bypass pipe communicating the third outdoor unit connection pipe and the second outdoor unit connection pipe; and a bypass valve provided in the bypass pipe.

According to one embodiment, this outdoor unit of an air conditioner includes a compressor, a heat exchanger, an expansion valve, a blower fan, electrical components, and a heat sink. The heat exchanger includes a first group constituted of at least one of the plurality of heat exchangers and a second group constituted of at least one of the plurality of heat exchangers not belonging to the first group. The expansion valve includes a first expansion valve and a second expansion valve. The heat sink is arranged on the flow path of the refrigerant on the upstream side of a confluence position of the refrigerant branches condensed by the heat exchangers of the first group and the second group and on the downstream side of the second expansion valve.

According to one embodiment, in a low speed drive of outdoor fans, a first flow rate adjusting valve in a main outdoor heat exchanger side is narrowed to a closing degree or a close range thereof, and an opening degree of a second flow rate adjusting valve is controlled such that a supercooling degree of refrigerant in auxiliary outdoor heat exchangers becomes constantly a target value.

An air conditioner includes a refrigerant circuit and a blower. A refrigerant flow path switching mechanism is configured to be switched to a first switching state to allow refrigerant to flow through a reheater, a first expansion valve, and a cooler in this order in the refrigerant circuit. The refrigerant flow path switching mechanism is configured to be switched to a second switching state to allow the refrigerant to flow through the reheater, the first expansion valve, and the cooler in this order in the refrigerant circuit. The reheater and the cooler are configured to allow air blown by the blower to pass through the cooler and then pass through the reheater during either of the first switching state and the second switching state.