Abstract: An air-conditioning apparatus includes: an outdoor unit including a compressor that compresses and discharges refrigerant to a refrigerant circuit; an indoor unit including a load-side heat exchanger that causes heat exchange to be performed between air in an air-conditioned space and a heat medium subjected to heat exchange with the refrigerant; a flow rate detection unit that detects a flow rate of the heat medium; and an alarm unit provided in the indoor unit. The alarm unit includes a determination unit and an abnormality alarm unit. The determination unit determines whether an abnormality occurs in the indoor unit or not based on the flow rate detected by the flow rate detection unit. The abnormality alarm unit outputs an alarm when the determination unit determines that the abnormality occurs in the indoor unit.

Abstract: An air-conditioning apparatus includes: a heat medium circulation circuit including: a heat medium device, a heat medium pipe, a pump, a heat medium detection unit, and a controller that includes a count unit to count an air-conditioning operation time and count a pump operation time based on heat medium detection information of the heat medium detection unit, a storage unit storing a set air-conditioning time and a set pump time, a comparison unit to compare the air-conditioning operation time with the set air-conditioning time and compare the pump operation time with the set pump time, and a device control unit to control driving of the pump so that the pump operation time reaches or exceeds the set pump time when the air-conditioning operation time is longer than or equal to the set air-conditioning time and the pump operation time is shorter than the set pump time.

Abstract: An air-conditioning apparatus according to the present disclosure includes a heat medium circulation circuit, a heat-source-side device, and a voltage drop device. In the heat medium circulation circuit, a pump, an indoor heat exchanger, and a flow control device are connected by pipes to circulate the heat medium. The pump sends a heat medium that contains water or brine and transfers heat. The indoor heat exchanger causes heat exchange to be performed between the heat medium and an indoor air in an air-conditioned space. The flow control device controls a flow rate of the heat medium in the indoor heat exchanger. The heat-source-side device heats or cools the heat medium before the heat medium is sent to the indoor heat exchanger. The voltage drop device reduces a voltage that is applied to the pump based on a value of a current that is supplied to the pump, in association with a flow rate of the heat medium in the heat medium circulation circuit.

Abstract: A free cooling outdoor unit includes: a refrigerant circuit through which refrigerant circulates; a brine circuit through which brine circulates; a water circuit through which water circulates; a fan configured to send air to the second heat exchanger; a flow control valve configured to control a circulation amount of the brine in the brine circuit; a water temperature detection sensor configured to detect a water temperature in the water circuit; an outside air temperature sensor; and a controller configured to control, where the outside air temperature is equal to or lower than a freezing temperature of the brine, the circulation amount of the brine based on the water temperature such that a brine temperature is prevented from reaching a temperature equal to or lower than the freezing temperature of the brine.

Abstract: An outdoor unit for a refrigeration cycle apparatus includes: a heat exchanger having an outer surface inclined downward; a drain pan on which the heat exchanger is set; a top frame on which a fan is set, the top frame being disposed at a top of the heat exchanger; and a support attached to the drain pan and the top frame, the support extending between the drain pan and the top frame.

Abstract: The heat-medium cycle circuit includes a discharge mechanism including a discharge valve, the discharge mechanism being configured to, when the discharge valve is open, discharge air present inside the heat-medium cycle circuit to the outside of the heat-medium cycle circuit. The air-conditioning apparatus is configured to execute an air discharge operation mode in which the air present inside the heat-medium cycle circuit is discharged to the outside of the heat-medium cycle circuit. The air discharge operation mode includes a first operation mode, and a second operation mode performed after the first operation mode. The first operation mode is an operation mode in which, with the discharge valve being closed, an operation similar to a cooling operation is performed. The second operation mode is an operation mode in which, with the discharge valve being open, an operation similar to a heating operation is performed.

Abstract: When heating is being performed, and a temperature detected by a temperature sensor is lower than a first determination value, a controller opens the flow rate control valve corresponding to a heat exchanger, of the third heat exchangers, to which a request for air conditioning has not been made, and closes the flow rate control valve corresponding to a heat exchanger, of the third heat exchangers, to which the request for air conditioning has been made. When heating is being performed, and the temperature detected by the temperature sensor is higher than a second determination value, the controller opens the flow rate control valve corresponding to the heat exchanger to which the request for air conditioning has been made, and closes the flow rate control valve corresponding to the heat exchanger to which the request for air conditioning has not been made.

Abstract: An air-conditioning apparatus includes: a heat-medium transfer device including a pump provided to transfer a heat medium that contains water or brine and transfers heat; a plurality of indoor units each of which includes an indoor heat exchanger provided to cause heat exchange to be performed between indoor air and the heat medium, and a flow control valve provided to adjust a flow rate of the heat medium that flows through the indoor heat exchanger, the plurality of indoor units being connected to the heat-medium transfer device by respective heat medium pipes; and a controller provided to control an opening degree of the flow control valve.

Abstract: An air-conditioning device includes a refrigerant circuit including a compressor, a heat source-side heat exchanger, an expansion unit, and an intermediate heat exchanger connected by a refrigerant pipe, through which refrigerant circulates; and a heat medium circuit including a pump, the intermediate heat exchanger, and a load-side heat exchanger connected by a heat medium pipe, through which heat medium circulates. A discharge unit connected downstream of the intermediate heat exchanger in the heat medium circuit discharges fluid flowing through the heat medium pipe, depending on pressure of the fluid. A refrigerant concentration detector detects concentration of the refrigerant contained in the fluid discharged from the discharge unit. A notification device notifies leakage of the refrigerant. A controller activates the notification device depending on the concentration of the refrigerant detected.

Abstract: An air conditioning apparatus has a first mode and a second mode as operation modes. In the first mode, a degree of opening of a first flow rate adjustment valve is fixed to a first degree of opening smaller than 100% and greater than 0%, and an operation frequency of a compressor is varied in accordance with air conditioning performance required of a third heat exchanger. In the second mode, the degree of opening of the first flow rate adjustment valve is varied in accordance with air conditioning performance required of the third heat exchanger. When a difference between the air conditioning performance required of the third heat exchanger and air conditioning performance offered by the third heat exchanger becomes greater than a determination value, the operation mode is changed from the first mode to the second mode.

Abstract: A chilling unit includes a casing, a refrigerant circuit in which a compressor, a heat-source heat exchanger, a first expansion unit, a second expansion unit, and a refrigerant-to-heat medium heat exchanger are connected by a refrigerant pipe and through which refrigerant flows, the refrigerant circuit being placed in the casing, and an injection circuit in which a portion between the first expansion unit and the second expansion unit is connected to the compressor by an injection pipe, the injection circuit being placed in the casing.

Abstract: A chilling unit includes a machine room unit to accommodate a compressor and a heat exchanger, and a plurality of air heat exchangers placed on top of the machine room unit. The air heat exchangers include a pair of air heat exchangers including two air heat exchangers opposite to each other in a lateral direction. They are inclined such that respective upper end portions of the two air heat exchangers have a spacing between each other greater than a spacing between respective lower end portions of the two air heat exchangers. In the lateral direction, the machine room unit has a top width greater than a heat-exchanger bottom width, the top width is one between side walls in a top face portion of the machine room unit, the bottom width is defined as a width between outer side faces of the respective lower end portions of the two air heat exchangers.

Abstract: A heat source device includes a heat medium channel through which a heat medium flows, a plurality of refrigerant circuits through which refrigerant circulates, and a plurality of heat-medium heat exchangers configured to cause heat exchange to be performed between the heat medium in the heat medium channel and the refrigerant in the refrigerant circuits. The plurality of heat-medium heat exchangers include a first heat-medium heat exchanger to which at least one of the refrigerant circuits is connected and a second heat-medium heat exchanger to which a greater number of the refrigerant circuits are connected than to the first heat-medium heat exchanger.

Abstract: A refrigeration cycle apparatus includes a refrigerant circuit in which a compressor, a refrigerant flow switching device, an air-side heat exchanger, an expansion valve, a water-side heat exchanger, and an accumulator are connected by refrigerant pipes and refrigerant is circulated. G/A is less than or equal to a predetermined threshold ?, where G [L] is a difference in volume between the air-side heat exchanger and the water-side heat exchanger, and A [L] is a volume of the refrigerant circuit.

Abstract: An air conditioning apparatus includes, a first heat exchanger, a second heat exchanger configured to exchange heat between a first heat medium and a second heat medium, flow rate control valves, and a pump. In a heating mode, a controller is configured to open the flow rate control valve corresponding to a heat exchanger, of the third heat exchangers, to which a request for air conditioning has been made, and to close the flow rate control valve(s) corresponding to a heat exchanger(s), of the third heat exchangers, to which the request for air conditioning has not been made. In a defrosting mode, when a temperature of the second heat medium is lower than a first determination temperature, the controller is configured to open at least one of the flow rate control valve(s) corresponding to the heat exchanger(s) to which the request for air conditioning has not been made.

Abstract: A free cooling system includes a plurality of free cooling outdoor units each including a heat medium circuit, a controller, and a communication unit, the heat medium circuit being configured by connecting a heat medium pump, a first heat exchanger, and a heat source side of a second heat exchanger by pipes, a heat medium circulating in the heat medium circuit, the controller configured to control the heat medium pump, and the communication units performing communication with each other, wherein the plurality of free cooling outdoor units are coupled with each other by a load pipe that allows a load heat medium to flow to or flow out from a load side of each second heat exchanger.

Abstract: When a state in which a driving voltage of a pump is set to an upper limit voltage and an opening degree of at least one of a plurality of flow rate control valves is set to a maximum opening degree continues for a first determination time period, an operation frequency of a compressor is raised at a first time so as to increase an amount of heat exchange by a second heat exchanger. When an operation stop request is input, or an indoor temperature reaches a set temperature, in at least one of a plurality of third heat exchangers after the first time, the operation frequency of the compressor is lowered or the driving voltage of the pump is lowered.

Abstract: An air-conditioning system includes a plurality of indoor units; a relay unit including an intermediate heat exchanger configured to exchange heat between refrigerant and a heat medium; and a heat source unit configured to supply cooling energy or heating energy to each of the plurality of indoor units via the relay unit. The heat source unit and the relay unit are connected by a heat-source connection pipe through which the refrigerant flows, and the relay unit and the plurality of indoor units are connected by a load connection pipe through which the heat medium flows. The load connection pipe comprises a main pipe connecting between the relay unit and one of the indoor units provided at an end of the load connection pipe opposite to the relay unit. The main pipe has branch parts associated with the indoor units.

Abstract: A controller has a timer operation mode in which the operation of a refrigeration cycle that operates as a heat source or a cold source is started before a set operation start time of an indoor fan by a preliminary operation time period. In the timer operation mode, the controller calculates a heat capacity of water or brine, calculates a heat storage amount of a second heat medium from a temperature detected by a temperature sensor and the heat capacity, and determines the preliminary operation time period from the heat storage amount. By determining the preliminary operation time period in this manner, timer operation can be performed such that air at an appropriate temperature is blown from an indoor unit at the operation start time of the indoor fan, from the initial time at which an air conditioning apparatus is installed.

Abstract: An air conditioning apparatus uses a heat medium containing at least one of cold water and hot water. The air conditioning apparatus includes: a heat source device; a heat exchanger configured to exchange heat between the heat medium and air; a flow rate control valve configured to control a flow rate at which the heat medium is supplied to the heat exchanger; a temperature sensor configured to detect a temperature of the heat medium discharged from the heat exchanger; and a failure determination unit configured to detect presence or absence of an abnormality in a flow path of the heat medium based on the temperature detected by the temperature sensor and a commanded degree of opening for the flow rate control valve.