Abstract: An air-conditioning apparatus includes a refrigerant circuit in which a compressor, a flow switching device, an outdoor heat exchanger, an expansion device, and an indoor heat exchanger are connected by pipes and through which refrigerant flows, and a control device controlling an operation of the refrigerant circuit to perform switching between a heating operation and a defrosting operation. The control device includes a determination unit that determines, based on operation information regarding the refrigerant circuit, during the heating operation, whether to change a requirement for starting the defrosting operation, a changing unit that changes the requirement for starting the defrosting operation in accordance with a result of determination by the determination unit, and a switching unit that, when the requirement for starting the defrosting operation is satisfied, causes the flow switching device to perform switching to start the defrosting operation.

Abstract: An air-conditioning apparatus controls a decrease in efficiency of a refrigeration cycle, and includes a suction pipe having one end connected to a suction side of a compressor and an other end connected to an evaporator, a receiver connected to a refrigerant pipe connecting the evaporator and a condenser to each other, a first bypass pipe having one end connected to the receiver and an other end connected to the suction pipe and configured to supply refrigerant from the receiver to the suction pipe, a flow control valve provided to the first bypass pipe, a heat recovery portion disposed downstream of a portion of the suction pipe connected to the first bypass pipe, and a control device configured to control an opening degree of the flow control valve based on a degree of superheat of refrigerant in the heat recovery portion.

Abstract: A control unit is configured to set a rotation speed of a compressor to be lower than that in a defrosting operation and set an opening degree of a pressure reducing device to be equal to or greater than that in the defrosting operation during a first control time after completion of the defrosting operation, stop the compressor and set the opening degree of the pressure reducing device to be less than that in the first control time during a second control time after lapse of the first control time, and control a refrigerant circuit switching device to resume a heating operation after lapse of the second control time.

Abstract: An outdoor unit includes at least a compressor, a gas-liquid separator, and an outdoor heat exchanger of a refrigerant circuit, the refrigerant circuit being formed by connecting, by pipes, the compressor, a condenser, a pressure reducing device, the gas-liquid separator, and the outdoor heat exchanger that acts as an evaporator including at least a plurality of heat transfer tubes and an inlet header that distributes incoming refrigerant to the heat transfer tubes. The outdoor unit further includes a gas-liquid-separator bypass pipe, a gas-liquid-separator-side flow control valve, a header bypass pipe, a header-side flow control valve, and a determination device.

Abstract: A multi-room air-conditioning apparatus includes an outdoor unit, a relay unit connected to an outdoor unit by first and second connection pipes, and a plurality of indoor units connected to the relay unit. The outdoor unit includes a second gas-liquid separating device provided on the suction side of the compressor. The suction side of the compressor and the second gas-liquid separating device are connected to each other by a gas-side outlet pipe and a liquid-side outlet pipe.

Abstract: A refrigerant circuit includes: plural gas/liquid separators adapted to separate a two-phase gas-liquid refrigerant into refrigerant vapor and refrigerant liquid; a channel switching valve connected upstream of the gas/liquid separators and adapted to switch channels for the two-phase gas-liquid refrigerant by opening and closing; an evaporating heat exchanger adapted to accept inflow of the refrigerant liquid or the two-phase gas-liquid refrigerant, the refrigerant liquid produced by separation by the gas/liquid separators; a header installed upstream of the evaporating heat exchanger perpendicularly or at angles to the evaporating heat exchanger; a compressor installed downstream of the evaporating heat exchanger; and plural bypass routes connected to the respective gas/liquid separators and adapted to allow passage of the refrigerant vapor.

Abstract: 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.

Abstract: An air-conditioning apparatus controls a decrease in efficiency of a refrigeration cycle, and includes a suction pipe having one end connected to a suction side of a compressor and an other end connected to an evaporator, a receiver connected to a refrigerant pipe connecting the evaporator and a condenser to each other, a first bypass pipe having one end connected to the receiver and an other end connected to the suction pipe and configured to supply refrigerant from the receiver to the suction pipe, a flow control valve provided to the first bypass pipe, a heat recovery portion disposed downstream of a portion of the suction pipe connected to the first bypass pipe, and a control device configured to control an opening degree of the flow control valve based on a degree of superheat of refrigerant in the heat recovery portion.

Abstract: A multi-room air-conditioning apparatus includes an outdoor unit, a relay unit connected to an outdoor unit by first and second connection pipes, and a plurality of indoor units connected to the relay unit. The outdoor unit includes a second gas-liquid separating device provided on the suction side of the compressor. The suction side of the compressor and the second gas-liquid separating device are connected to each other by a gas-side outlet pipe and a liquid-side outlet pipe.

Abstract: A compact, readily-manufacturable heat exchanger and a refrigeration cycle apparatus equipped with the same are provided. One of opposite ends of a main body in a refrigerant flowing direction is provided with a first inlet communication hole that extends in a direction of arrangement of first refrigerant channels and that communicates with all of the first refrigerant channels. The other end is provided with a first outlet communication hole that extends in the direction of arrangement of the first refrigerant channels and that communicates with all of the first refrigerant channels.

Abstract: A heat exchanger in which inner wall surfaces of refrigerant passages through which a first refrigerant and a second refrigerant flow are constituted by a different metal and in which a heat exchange performance is improved. Second-refrigerant heat-transfer tubes that are formed with a metal different from a heat transfer block are each inserted through a corresponding second-refrigerant heat-transfer-tube insertion hole. The second-refrigerant heat-transfer tubes are formed with a metal with a different material from that of the heat transfer block.

Abstract: A heat exchanger includes a first flat pipe including plural through-holes through which a high-temperature fluid flows, a second flat pipe including plural through-holes through which a low-temperature fluid flows, a first tubular shape inlet header connected to one end of the first flat pipe, a first tubular shape outlet header connected to another end of the first flat pipe, a second tubular shape inlet header connected to one end of the second flat pipe, and a second tubular shape outlet header connected to another end of the second flat pipe. The first and second flat pipes are stacked with contacting flat surfaces. The low-temperature fluid flowing into the through-holes in the second flat pipe from the second inlet header is a fluid in a two-phase gas-liquid state, and flows into those through-holes in a substantially horizontal direction or in an upward direction relative to the substantially horizontal direction.