When starting a cooling operation mode from a non-operating mode, the blower device of the indoor unit from which the start command is originated is operated. When starting a heating operation mode from a non-operating mode, the blower device of the indoor unit from which the start command is originated is operated after the heat medium temperature becomes equal to or greater than a preconfigured temperature.

An air conditioner performs a heating operation and a cooling operation with enhanced heat exchange performance and also performs a heating continuous operation, while preventing increases in manufacturing cost and packaging volume. An air conditioner comprises a refrigerant circuit through which refrigerant circulates. A second heat exchanger includes a first refrigerant flow path and a second refrigerant flow path. A first port of the flow path switching device is connected to a discharge portion of a compressor. A second port is connected to a first heat exchanger. A third port is connected to an intake portion of the compressor. A fourth port is connected to a pipe that connects a branch point to the first refrigerant flow path. A fifth port is connected to the second refrigerant flow path. A sixth port is connected to the first refrigerant flow path.

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.

There is disclosed a reversible heat pump system 100 and a method of operating a reversible heat pump system to control the temperature of a process fluid of a chiller system 500. In a cooling mode, a working fluid is circulated for co-current flow with a process fluid at a heat exchanger 104 functioning as an evaporator heat exchanger, whereas in a heating mode, the working fluid is circulated for counter-current flow with the process fluid at the same heat exchanger 104 functioning as a condenser heat exchanger.

An air-conditioning apparatus includes: a first defrosting pipe branching from a main circuit to supply a portion of refrigerant discharged from a compressor to one of plural parallel heat exchangers to be defrosted; a second defrosting pipe which returns, to the main circuit, the refrigerant supplied through the first defrosting pipe to the one parallel heat exchanger; a first expansion device provided on the first defrosting pipe; a second expansion device provided on the second defrosting pipe to adjust a pressure of the refrigerant in the one parallel heat exchanger; and a third expansion device provided between a connection point between an outlet of the second defrosting pipe and the main circuit and one of plural indoor heat exchangers functioning as an evaporator, to adjust a pressure of the refrigerant in the one of the indoor heat exchangers; and a controller that controls the second and third expansion devices individually.

An accumulator includes a container, a low pressure refrigerant inlet tube, and a low pressure refrigerant outlet body including an upstream-side tubular section, a low pressure refrigerant turning back section and a downstream-side tubular section in the container. At least a part of the upstream-side tubular section is covered by a first outer tube with a gap between the upstream-side tubular section and the first outer tube, at least a part of the downstream-side tubular section is covered by a second outer tube with a gap between the downstream-side tubular section and the second outer tube, the first outer tube and the second outer tube communicate with each other via a bridging tube, and high pressure refrigerant passes through the gap between the upstream-side tubular section and the first outer tube, the bridging tube, and the gap between the downstream-side tubular section and the second outer tube.

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 air-conditioning apparatus includes a bypass pipe that has one end connected to the discharge side of a compressor and through which refrigerant exiting the compressor flows, an auxiliary heat exchanger that is connected to the other end of the bypass pipe and the suction part of the compressor, and cools refrigerant flowing through the bypass pipe and supplies the cooled refrigerant to the suction part of the compressor, and a flow regulating unit that is provided on the refrigerant outlet side of the auxiliary heat exchanger, and regulates the flow rate of refrigerant routed into the suction part of the compressor from the auxiliary heat exchanger.

A heating and cooling system includes a heat exchange section to transfer heat between refrigerant and air in both a heating mode and a cooling mode. The heat exchange section includes at least two refrigerant passes. Refrigerant is circuited through the refrigerant passes in the same direction in both the heating mode and the cooling mode, so that the overall flow orientation between the refrigerant passes and the air is a counter-flow orientation in both the heating mode and the cooling mode.

An air conditioning apparatus uses R32 as a refrigerant, and includes a compressor, a condenser, an expansion mechanism, an evaporator, an intermediate injection channel, a suction injection channel, a switching mechanism, a branch flow channel, first and second injection opening adjustable valves, an injection heat exchanger, a refrigerant storage tank, a bypass channel, and a control part. The switching mechanism switches between an intermediate injection condition in which refrigerant flows in the intermediate injection channel, and a suction injection condition in which refrigerant flows in the suction injection channel. The branch flow channel branches from a main refrigerant channel which joins the condenser and the evaporator, and guides the refrigerant to the intermediate injection channel and the suction injection channel. The bypass channel guides a gas component of the refrigerant accumulated inside the refrigerant storage tank to the intermediate injection channel and the suction injection channel.