An air-conditioning apparatus achieves improvement of safety and further achieves saving of energy without allowing a refrigerant to circulate in or near an indoor unit. The air-conditioning apparatus is configured such that heat medium pipes have a larger inner cross-sectional area per unit capacity than that of refrigerant pipes.

A heat-source-side heat exchanger is divided so that a heat-source-side heat exchanger that functions as an evaporator also functions as an intermediate cooler. Since, when an air conditioner includes a bypass pipe, a heat-source-side heat exchanger that functions as an evaporator and as an intermediate cooler also further functions as a radiator, operation efficiency is increased.

A heat-medium flow-path switching device and a heat-medium flow-rate adjusting device are integrated into an integrated heat-medium flow-rate adjusting device. The integrated heat-medium flow-rate adjusting device is configured to perform the heat-medium flow-path switching function and the meat-medium flow-rate adjusting function by driving and controlling a single drive unit. Moreover, the integrated heat-medium flow-path switching device is configured to perform a function of closing flow paths from/to a use-side heat exchanger added to the heat-medium flow-rate adjusting function.

An outdoor unit of an air-conditioner and two-pipe and three-pipe air-conditioning systems having the same are provided. The outdoor unit includes a compressor defining an outlet and an inlet; a first four-way valve defining a first valve communicated with the outlet, second and third ports communicated with the inlet; a second four-way valve defining second and third ports communicated with the inlet; an outdoor heat exchanger defining a first refrigerant valve Communicated with the fourth port of the first four-way valve; a first gas pipe defining a first end connected with the second and third ports of the first and second four-way valves and, the inlet; a second gas pipe defining a first end connected with the fourth port of the second four-way valve; a third gas pipe defining a first end connected with the outlet and a second end connected with the first port of the second four-way valve.

In an air-conditioning apparatus, when a plurality of pumps are all operating and a heat exchange amount in use-side heat exchangers is equal to or lower than a lower limit of a thermal capacity that can be conveyed in a heat medium circuit B, before at least one of the plurality of pumps is stopped, a refrigerant flow path in the intermediate heat exchanger connected to the pump that is to be stopped is closed. Then, the at least one of the plurality of pumps is stopped, and the thermal capacity required in at least one of the use-side heat exchangers in the rest of the plurality of pumps is conveyed.

A climate-control system may include a compressor, a thermal storage device, an outdoor heat exchanger, an indoor heat exchanger, a first expansion device, and a second expansion device. The compressor may include an intermediate-pressure inlet, an intermediate-pressure outlet, a discharge outlet, a suction-pressure pocket, and a plurality of compression pockets. The thermal storage device may include a conduit and a phase-change material surrounding the conduit. The first expansion valve, the second expansion valve, the outdoor heat exchanger, the indoor heat exchanger, and the thermal storage device may be in fluid communication with the compressor. The climate-control system is operable in a charging mode and a discharging mode, and is operable in a cooling mode and a heating mode. The thermal storage device may be configured to absorb heat from a working fluid or to transfer heat to the working fluid.

An air conditioner includes: use-side units that are each switchable between a cooling operation and a heating operation; and a heat-source-side unit including a compressor, a discharge pipe through which a refrigerant discharged from the compressor flows, a first main heat-source-side flow path and a second main heat-source-side flow path that branch off from the discharge pipe, a first heat-source-side heat exchanger, a second heat-source-side heat exchanger, a first economizer heat exchanger, and a second economizer heat exchanger. The first heat-source-side heat exchanger is connected to the first economizer heat exchanger in series in the first main heat-source-side flow path. The second heat-source-side heat exchanger is connected to the second economizer heat exchanger in series in the second main heat-source-side flow path.

An improved heat pump including an integrated system for the management of refrigerant charge is provided. The integrated system actively adjusts charge allocation and thereby optimizes operational efficiencies in all modes of operation. In one embodiment, the integrated system includes three four-way valves, two expansion valves, two one-way check valves, and a suction line accumulator to optimize charge allocation. The four-way valves dictate the mode switch and refrigerant flow directions, and the expansion valves automatically allocate refrigerant mass in active components and store excess charge in an idle heat exchanger and suction line accumulator by controlling the compressor discharge pressure (equivalent to controlling condenser subcooling degree) as a function of the entering air and water temperatures. The integrated system provides seven working modes and is uniquely suited for spacing cooling, spacing heating, and water heating in both residential and commercial applications.

An air conditioner and a method for controlling an air conditioner. The method may include detecting an outlet temperature of a compressor; detecting a change in temperature of a hot water supply pipe; determining a system error based on the outlet temperature of the compressor; and determining an abnormality in an adjustment valve based on the temperature of the hot water supply pipe when a system error is determined.

An air conditioner, including a first compressor that compresses refrigerant; a second compressor that compresses the refrigerant; an indoor heat exchanger that performs heat exchange between the refrigerant and air; a first four-way valve connected to the first compressor; a first outdoor heat exchanger connected to the first four-way valve; a first valve connected to the first four-way valve; a second four-way valve connected to the second compressor; a second outdoor heat exchanger connected to the second four-way valve; a second valve connected to the second four-way valve; a first valve pipe that connects the first four-way valve and the second four-way valve; a second valve pipe that connects the first valve and the second valve; and a third four-way valve connected to the first valve pipe, the second valve pipe, the first compressor and the second compressor, and the indoor heat exchanger.