An air conditioner includes: a heat-source-side unit including a compressor and a heat-source-side heat exchanger; use-side units each including a use-side heat exchanger; an intermediate unit that causes the use-side heat exchanger of each of the use-side units to individually function as an evaporator or a radiator of a refrigerant; and three or more connection pipes that connect the heat-source-side unit to the intermediate unit. The intermediate unit includes: an ejector that pressurizes the refrigerant; and a gas-liquid separator into which the refrigerant flowing out from the ejector flows. The refrigerant that has released heat in any of the use-side units that perform a heating operation is not pressurized by the ejector.

The invention discloses a multi-split system with partitioned control. An output end of a compressor is in communication with first interfaces of a first four-way valve, a second four-way valve, and a third four-way valve respectively, a third interface of the first four-way valve is in communication with one end of an outdoor heat exchanger, a second interface of the second four-way valve is in communication with one end of one indoor unit set therein, a third interface of the third four-way valve is in communication with one end of the other indoor unit set, and the other end of the outdoor heat exchanger and the other ends of the indoor unit sets are in communication with each other in a convergence manner; the remaining interfaces of the second four-way valve and the third four-way valve are all in communication with an air return end of the compressor.

A system comprising a compressor, a first valve coupled to the compressor and to a first coil, a first expansion valve coupled to the first coil, and a second expansion valve. The second expansion valve coupled to a second coil. A second valve is coupled to the second coil and the compressor. A third valve is coupled to the compressor and a third coil. In response to receiving a heating demand that is below a threshold heating demand, a controller induces an artificial heating demand.

A system comprising a compressor, a first valve coupled to the compressor and coupled to a first coil, a first expansion valve coupled to the first coil, a second coil, and a second expansion valve. The second expansion valve coupled to a third coil, a second valve coupled to the compressor and the third coil. A controller operable to operate the first valve, the first expansion valve, the second expansion valve, and the second valve. The second coil is coupled to the compressor and the refrigerant flows from the second coil to the compressor.

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 conditioning system includes: an outdoor unit; indoor units; one or more refrigerant flow path switching devices that switch flow paths of a refrigerant between the outdoor unit and the indoor units; and external pipes extending from the outdoor unit to the indoor units. The air conditioning system is configured such that a sum of a first value and a first correction value is equal to or less than a predetermined upper limit value determined based on an industrial standard, where the first value is based on a total length of the external pipes from the outdoor unit to the indoor units via the one or more refrigerant flow path switching device, and the first correction value is based on a sum of capabilities of the indoor units connected to the one or more refrigerant flow path switching devices.

An air conditioning system includes a storage medium and an air conditioning system, for a three-pipe air conditioning system, the three-pipe air conditioning system includes a compressor, an outdoor heat exchanger, an indoor heat exchanger, a gas-liquid separator, a first pipeline, a second pipeline and a third pipeline; the oil return control method comprises the following steps: controlling the compressor to operate at a first frequency in a refrigerating mode; judging whether the operation duration of the refrigerating mode reaches a first preset time or not; if so, the air conditioning system enters an oil return state, and the compressor, the third pipeline, the second pipeline and the gas-liquid separator are controlled to be communicated in sequence to form a refrigerant circulation loop.

In an air-conditioning apparatus including a plurality of indoor units connected to a heat medium converter and a plurality of remote controllers respectively provided for the indoor units, the remote controllers each include a temperature sensor that detect a temperature of a corresponding space to be air-conditioned, and are each configured to communicate with a heat medium converter controller of the heat medium converter and an indoor unit controller of the corresponding indoor unit, transmit an instruction to start and stop an operation and data related to rotation speed of an indoor air-sending device to the corresponding indoor unit controller, and transmit the instruction to start and stop the operation, and a target temperature and a temperature detected by the temperature sensor or a difference therebetween, to the heat medium converter controller.

A refrigeration cycle apparatus includes: a first four-way valve having first to fourth ports; a second four-way valve and a third four-way valve each having fifth to eighth ports; a compressor; a discharge pipe connecting a discharge port of the compressor and the first port; a suction pipe connecting a suction port of the compressor and the second port; a first high pressure pipe connecting the discharge pipe and the fifth ports; a second high pressure pipe connecting the third port and the first high pressure pipe; a first valve provided at the first high pressure pipe; a second valve provided at the second high pressure pipe; a low pressure pipe connecting the suction pipe and the sixth ports; a first outdoor heat exchanger connected with the seventh port of the second four-way valve; a second outdoor heat exchanger connected with the seventh port of the third four-way valve; and an indoor heat exchanger connected with the fourth port.

A valve body in each of heat medium flow switching devices has an open portion. When the length from a connection between a first passage pipe and a third passage pipe to a connection between a second passage pipe and the third passage pipe is defined as a casing passage width, a valve body passage width of the open portion in a direction substantially perpendicular to the axis of the valve body is smaller than the casing passage width.