Abstract: A refrigeration cycle apparatus includes a heat source side unit, a relay unit, and a plurality of load side units, the heat source side unit and the relay unit are connected by using a low-pressure pipe and a high-pressure pipe, and the relay unit and each of the plurality of load side units are connected by using a corresponding liquid branch pipe and a corresponding gas branch pipe. The heat source side unit includes a compressor configured to compress refrigerant, at least one flow switching valve configured to change a passage of refrigerant based on an operation mode, and at least one heat source side heat exchanger, and the relay unit includes six-way valves or pairs of four-way valves.

Abstract: In an air-conditioning system that divides a room to be air-conditioned into a plurality of areas and controls air-conditioning of each of the plurality of areas, a set temperature of an occupied area in which somebody is present is determined as a target temperature of the occupied area. Target temperatures of unoccupied areas in which nobody is present are determined such that the air-conditioning mode set for the occupied area weakens stepwise from an adjacent area located next to the occupied area toward a distal area located farthest from the occupied area.

Abstract: An air conditioning system comprises one or more air conditioners through which refrigerant circulates, and a first controller. For each of one or more indoor units, a score corresponding to a cost of using the indoor unit is preset. The first controller calculates, for each of the one or more air conditioners, a first total value of a score of each of the one or more indoor units included in the air conditioner. The first controller calculates a second total value of the first total value of each of the one or more air conditioners. When an electrical energy limit condition is satisfied, the first controller sets for each of the one or more air conditioners a drive frequency for a compressor included in the air conditioner according to a ratio of the first total value of the air conditioner to the second total value.

Abstract: A refrigeration cycle apparatus includes a refrigerant circuit, through which refrigerant is circulated, including a compressor, a heat source side heat exchanger, a first expansion device, and a load side heat exchanger, a controller controlling the refrigerant circuit, and a bypass pipe that branches off from a high-pressure pipe extending from the compressor to the first expansion device and that is connected to a low-pressure pipe on a suction side of the compressor. The apparatus further includes a precooling heat exchanger that is provided in the bypass pipe and that cools the refrigerant diverted to the bypass pipe, a second expansion device that is provided in the bypass pipe and that reduces a pressure of the refrigerant cooled by the precooling heat exchanger, and a refrigerant cooler that is provided in the bypass pipe and that cools the controller with the refrigerant reduced in pressure by the second expansion device.

Abstract: An air-conditioning apparatus includes: a refrigerant circuit in which a compressor, a four-way valve, a heat source-side heat exchanger, an expansion valve and a load-side heat exchanger are connected; and a controller which controls a refrigeration cycle in which refrigerant is circulated in the refrigerant circuit, to switch a flow passage for the refrigerant in accordance with which of a cooling operation, a heating operation and a defrosting operation is performed. The controller includes: a refrigeration-cycle control unit which controls the four-way valve to switch the flow passage of the refrigerant when the operation to be performed is switched from the heating operation to the defrosting operation; and a compressor control unit which sets an operation frequency of the compressor at a value lower than an operation frequency which is applied during the heating operation, when the operation is switched from the heating operation to the defrosting operation.

Abstract: In an air-conditioning system that divides a room to be air-conditioned into a plurality of areas and controls air-conditioning of each of the plurality of areas, a set temperature of an occupied area in which somebody is present is determined as a target temperature of the occupied area. Target temperatures of unoccupied areas in which nobody is present are determined such that the air-conditioning mode set for the occupied area weakens stepwise from an adjacent area located next to the occupied area toward a distal area located farthest from the occupied area.

Abstract: An air-conditioning apparatus includes: a refrigerant circuit in which a compressor, a four-way valve, a heat source-side heat exchanger, an expansion valve and a load-side heat exchanger are connected; and a controller which controls a refrigeration cycle in which refrigerant is circulated in the refrigerant circuit, to switch a flow passage for the refrigerant in accordance with which of a cooling operation, a heating operation and a defrosting operation is performed. The controller includes: a refrigeration-cycle control unit which controls the four-way valve to switch the flow passage of the refrigerant when the operation to be performed is switched from the heating operation to the defrosting operation; and a compressor control unit which sets an operation frequency of the compressor at a value lower than an operation frequency which is applied during the heating operation, when the operation is switched from the heating operation to the defrosting operation.

Abstract: An air-conditioning apparatus includes at least one system including a heat-medium conveying device, a heat-medium flow regulator, and a heat-medium flow control device, as a heat medium system capable of regulating a flow rate of a heat medium supplied to a heat source device-side heat exchanger exchanging heat between refrigerant and the heat medium. The air-conditioning apparatus switches each of a plurality of use-side heat exchangers to a cooling operation or a heating operation in accordance with a control command to perform a cooling and heating simultaneous operation. The refrigerant is caused to flow through the heat source device-side heat exchanger depending on a ratio of a total cooling capacity and a total heating capacity of the plurality of use-side heat exchangers.

Abstract: A refrigeration cycle apparatus includes a refrigerant circuit, through which refrigerant is circulated, including a compressor, a heat source side heat exchanger, a first expansion device, and a load side heat exchanger, a controller controlling the refrigerant circuit, and a bypass pipe that branches off from a high-pressure pipe extending from the compressor to the first expansion device and that is connected to a low-pressure pipe on a suction side of the compressor. The apparatus further includes a precooling heat exchanger that is provided in the bypass pipe and that cools the refrigerant diverted to the bypass pipe, a second expansion device that is provided in the bypass pipe and that reduces a pressure of the refrigerant cooled by the precooling heat exchanger, and a refrigerant cooler that is provided in the bypass pipe and that cools the controller with the refrigerant reduced in pressure by the second expansion device.

Abstract: An air-conditioning apparatus and an air-conditioning system including a first unit including a compressor and a first heat exchanger, and a plurality of second units that each include a second heat exchanger. Each of the plurality of second units connect to the first unit via a plurality of branched pipes and a plurality of valves. The air-conditioning apparatus and air-conditioning system also include a storage unit that stores connection information indicating a relationship of connection between the plurality of second units and the plurality of branched pipes, and a control unit that detects whether the connection information includes a closed path pipe.

Abstract: Provided is a first unit including a first unit including a compressor and a first heat exchanger; a plurality of second units each including a second heat exchanger and each being connected to the first unit via a plurality of branched pipes; a plurality of valves configured to open to permit refrigerant flows and close to not permit the refrigerant flows; a storage unit configured to store connection information indicating a relationship of connection between the plurality of second units and the plurality of pipes; a closed path pipe that is any of the plurality of branched pipes to which no second unit is connected, and a control unit configured to detect whether the closed path pipe is included in the connection information.

Abstract: An air-conditioning apparatus includes a heat medium system configured to control a flow rate of the heat medium supplied to the heat source unit side heat exchanger that exchanges heat between refrigerant and the heat medium, the heat medium system having at least one system of a heat medium conveyor, a heat medium flow rate adjuster, and a heat medium flow rate control device. In the air-conditioning apparatus, the operation of each of use-side heat exchangers is changed to a cooling operation or a heating operation in accordance with a control command, and a cooling and heating concurrent operation is performed. The refrigerant is caused to flow through the heat source unit side heat exchanger in accordance with the ratio of the total cooling capacity of the use-side heat exchangers to the total heating capacity of the use-side heat exchangers.

Abstract: An air-conditioning apparatus has different two modes including a response detection diagnosis in which a control unit diagnoses a trouble of a component device during the trouble diagnosis operation based on presence or absence of a response from the operational state sensor when the mode has forcibly changed the device operation, and a performance detection diagnosis in which a trouble is detected by a detection value of the operational state sensor at a time when the operational state of the trouble diagnosis operation is stable, and the performance detection diagnosis is executed after the response detection diagnosis is executed.

Abstract: Provided is a first unit including a first unit including a compressor and a first heat exchanger; a plurality of second units each including a second heat exchanger and each being connected to the first unit via a plurality of branched pipes; a plurality of valves configured to open to permit refrigerant flows and close to not permit the refrigerant flows; a storage unit configured to store connection information indicating a relationship of connection between the plurality of second units and the plurality of pipes; a closed path pipe that is any of the plurality of branched pipes to which no second unit is connected, and a control unit configured to detect whether the closed path pipe is included in the connection information.

Abstract: An air-conditioning apparatus includes a heat medium system configured to control a flow rate of the heat medium supplied to the heat source unit side heat exchanger that exchanges heat between refrigerant and the heat medium, the heat medium system having at least one system of a heat medium conveyor, a heat medium flow rate adjuster, and a heat medium flow rate control device. In the air-conditioning apparatus, the operation of each of use-side heat exchangers is changed to a cooling operation or a heating operation in accordance with a control command, and a cooling and heating concurrent operation is performed. The refrigerant is caused to flow through the heat source unit side heat exchanger in accordance with the ratio of the total cooling capacity of the use-side heat exchangers to the total heating capacity of the use-side heat exchangers.

Abstract: The air-conditioning apparatus includes a compressor; a heat source side heat exchanger; a use side pressure-reducing mechanism; a use side heat exchanger and an accumulator connected by a pipe so that a refrigerant circulates therethrough; a high-low pressure bypass pipe; a high-low pressure bypass unit installed in the high-low pressure bypass pipe; and a unit controller configured to perform a refrigerant amount detection operation in which an operation frequency of the compressor is controlled so that a value of an evaporating temperature becomes an evaporating temperature target value of the compressor to discharge a liquid-state refrigerant of the refrigerant from the accumulator, and control an opening degree of the high-low pressure bypass unit in performing the refrigerant amount detection operation.

Abstract: An air-conditioning apparatus includes at least one system including a heat-medium conveying device, a heat-medium flow regulator, and a heat-medium flow control device, as a heat medium system capable of regulating a flow rate of a heat medium supplied to a heat source device-side heat exchanger exchanging heat between refrigerant and the heat medium. The air-conditioning apparatus switches each of a plurality of use-side heat exchangers to a cooling operation or a heating operation in accordance with a control command to perform a cooling and heating simultaneous operation. The refrigerant is caused to flow through the heat source device-side heat exchanger depending on a ratio of a total cooling capacity and a total heating capacity of the plurality of use-side heat exchangers.

Abstract: An air conditioning system includes: first and second utilization side heat exchangers and a heat source side heat exchanger respectively connected in series; a compressor connected between the first utilization side heat exchanger and the heat source side heat exchanger; an expansion valve connected between the first utilization side heat exchanger and the second utilization side heat exchanger; a pressure control device connected between the second utilization side heat exchanger and the heat source side heat exchanger; and a bypass valve connected between the expansion valve and the heat source side heat exchanger. The bypass valve provides a variable amount of liquid refrigerant flowing from the expansion valve to the heat source side heat exchanger. The pressure control device and the bypass valve cooperate with each other to keep a temperature of the compressor below a maximum allowable temperature predetermined for the compressor.

Abstract: Provided is a first unit including a first unit including a compressor and a first heat exchanger; a plurality of second units each including a second heat exchanger and each being connected to the first unit via a plurality of branched pipes; a plurality of valves configured to open to permit refrigerant flows and close to not permit the refrigerant flows; a storage unit configured to store connection information indicating a relationship of connection between the plurality of second units and the plurality of pipes; a closed path pipe that is any of the plurality of branched pipes to which no second unit is connected, and a control unit configured to detect whether the closed path pipe is included in the connection information.

Abstract: A first bypass pipe has one end connected to a main pipe extending from a compressor to an indoor heat exchanger, and its other end branched off into parts that are each connected to the main pipe on an inlet side of an outdoor heat exchanger, and a second bypass pipe has one end connected to an injection port communicating with the compression chamber of the compressor in which compression is taking place and its other end branched off into parts that are each connected to the main pipe on an outlet side of the outdoor heat exchangers. During a defrosting operation that removes frost on the outdoor heat exchangers, a part of the refrigerant discharged from the compressor is supplied from the first bypass pipe to the outdoor heat exchanger to be defrosted, and is then passed through the second bypass pipe and injected from the injection port of the compressor.