A switching device for a multi-split air conditioner, comprising: a housing, a gas-liquid separator, multiple first indoor unit interface pipes, at least one heat exchange component, and multiple second indoor unit interface pipes. The gas-liquid separator is provided with an inlet to an outdoor unit, a first outlet, and a second outlet. The multiple first indoor unit interface pipes and the multiple second indoor unit interface pipes are spaced from each other in a first direction. The first outlet is connected to multiple first interfaces by means of the multiple first indoor unit interface pipes, respectively. The first and second indoor unit interface pipes are spaced apart in a second direction. Some of the first and second indoor unit interface pipes are spaced apart from the rest of the first indoor unit interface pipes and the rest of the second indoor unit interface pipes in the second direction.

A target condensing temperature and a target evaporating temperature are changed in accordance with a load of each load side unit obtained by using load detection means, and an operating frequency of a compressor and a rotation speed of a fan are controlled such that a condensing temperature obtained by using temperature detection means coincides with the target condensing temperature and an evaporating temperature obtained by using the temperature detection means coincides with the target evaporating temperature.

An air conditioner is provided that may include at least one compressor that compresses a refrigerant to a high pressure; a plurality of heat exchanger that condenses the refrigerant compressed in the at least one compressor; a plurality of outdoor valves, respectively, provided at an outlet side pipe of the plurality of heat exchangers; a gas liquid separator that separates the refrigerant into gas and liquid refrigerants and supplies the gas refrigerant to the at least one compressor; and one or more bypass devices connected to the outlet side pipe of one or more of the plurality of heat exchangers and an inlet side pipe of the gas liquid separator, the one or more bypass devices controlling a flow of the liquid refrigerant. During a cooling low load operation in which a portion of the plurality of heat exchangers is operating, a liquid refrigerant loaded into a heat exchanger of the plurality of heat exchangers, which is not operated, may flow through the one or more bypass device.

Electricity wasting due to an unnecessary operation is prevented and the usability is improved. A multi air conditioner includes an outdoor unit, a first indoor unit and a second indoor unit. The first indoor unit and the second indoor unit are connected to the outdoor unit and are respectively disposed in different rooms. When the first indoor unit is operated based on a first operating mode, if an operation start instruction based on a second operating mode which is different from the first operating mode is sent to the second indoor unit from a remote controller without using an internet (S5: YES, S7: NO), the first indoor unit becomes an operation stop state and the second indoor unit starts an operation based on the second operating mode on condition that the last instruction to the first indoor unit is sent from a smart phone via the internet (S9: YES) (S12).

A refrigeration cycle apparatus includes: a refrigerant circuit in which a compressor, a heat-source-side heat exchanger, a first expansion device, a second expansion device, and a load-side heat exchanger are sequentially connected by refrigerant pipes and in which refrigerant is circulated; a controller that controls the refrigerant circuit; a bypass pipe extending from a liquid pipe between the first expansion device and the second expansion device toward a suction side of the compressor; a third expansion device provided at the bypass pipe to decompress the refrigerant that flows through the bypass pipe; and a refrigerant cooler provided at the bypass pipe and downstream of the third expansion device to cause heat exchange to be performed between the refrigerant decompressed by the third expansion device and heat generated from the controller.

Distributed Climate-Control Systems and Methods with Distributed Protection against Refrigerant Loss: the system includes a central condenser unit in combination with a distributed network of air handling units. Each air handler includes an evaporator, in which condensed refrigerant can undergo a phase change while absorbing heat of vaporization, plus a heat exchanger (e.g. a coil) which permits the heat absorption of the evaporator to be coupled to a forced airflow. Preferably the evaporator includes a metering device to provide variable refrigerant flow, and hence variable rates of heat transfer. The individual evaporators also include a sensor to detect ambient levels of the refrigerant, electrically operable cutoff valves which permit the evaporator to be isolated from both the liquid-phase and the gas-phase refrigerant flows. Local control logic is preferably connected to shut the cutoff valves whenever an ambient refrigerant concentration is found to exceed a tolerable level.

Disclosed is an air conditioning system, comprising M outdoor units (101) for providing warm or cold sources, M being a positive integer; N indoor units (102) for receiving a warm or cold source supplied by one or more of the at least one outdoor unit (101), N being a positive integer; a control system (103) comprising a lubricating oil distributing subsystem (1031) connected to the M outdoor units (101); a cold medium distributing subsystem (1032) connected to the M outdoor units (101); and a control subsystem (1033) connected to the M outdoor units (101), the N indoor units (102), the lubricating oil distributing subsystem (1031) and the cold medium distributing subsystem (1032). Further disclosed are a control system and an air-conditioning control method.

A heat source unit has a capacity-variable heat source-side compressor and a heat source-side heat exchanger which functions as a radiator of refrigerant. Usage units are connected to the heat source unit and have usage-side heat exchangers, respectively, which function as evaporators of refrigerant and cool an aqueous medium. An operating capacity controller controls the capacity of the heat source-side compressor so that evaporation temperature of refrigerant of each of the usage-side heat exchangers reaches a first target evaporation temperature. A decision unit calculates second target evaporation temperatures at which outlet temperatures of the aqueous medium in the usage-side heat exchangers of the respective operating usage units reach predetermined set temperatures, and decides a minimum value of the second target evaporation temperatures as the first target evaporation temperature.

An air-conditioning apparatus includes a heat medium circuit in which a compressor, a flow switching unit, a flow regulating unit, a gas header, a heat source-side heat exchanger, a distributor, an expansion unit, and a use-side heat exchanger are connected by a pipe, and during a defrosting operation to defrost the heat source-side heat exchanger, heat medium circulates, in order, the compressor, the flow switching unit, the gas header, the heat source-side heat exchanger, the distributor, the expansion unit, and the use-side heat exchanger. The heat source-side heat exchanger includes a first heat exchange unit, and a second heat exchange unit provided lower than the first heat exchange unit. The flow regulating unit is configured to, during the defrosting operation, regulate a flow rate of heat medium flowing through the first heat exchange unit and a flow rate of heat medium flowing through the second heat exchange unit.

An air conditioner 1 of the embodiment of the present invention, when all compressors 21a-21c have been stopping for a given time or more, starts an air conditioning operation without performing pressure equalizing control in switch units 6a-6d with starting the operation of the air conditioner 1. Also, when the stopping time of all compressors 21a-21c is less than the given time, the air conditioner 1 performs the pressure equalizing control by controlling switch units 6a-6d with starting the operation of the air conditioner 1. In this case, when the stopping time reaches the given time during execution of the pressure equalizing processing control, the pressure equalizing processing control being executed is stopped and the air conditioning operation is started.