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: 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 air-conditioning device includes a refrigerant circuit including a compressor, a heat source-side heat exchanger, an expansion unit, and an intermediate heat exchanger that are connected by a refrigerant pipe, and through which refrigerant circulates; a heat medium circuit including a pump, the intermediate heat exchanger, and a load-side heat exchanger that are connected by a heat medium pipe, and through which heat medium circulates; a discharge unit connected downstream of the intermediate heat exchanger in the heat medium circuit and configured to discharge fluid flowing through the heat medium pipe, to outside of the heat medium pipe, depending on pressure of the fluid; a refrigerant detection device configured to detect concentration of the refrigerant contained in the fluid discharged from the discharge unit; a notification device configured to notify leakage of the refrigerant; and a controller configured to activate the notification device depending on the concentration of the refrigerant detected

Abstract: A relay includes a first relay unit and a second relay unit provided between an outdoor unit and an indoor unit to allow refrigerant to circulate between the first relay unit and the outdoor unit and between the second relay unit and the outdoor unit, and a heat medium circuit connecting the first relay unit and the second relay unit to the indoor unit to allow a heat medium to circulate through the heat medium circuit. The second relay unit is installed above or on a top of the first relay unit.

Abstract: An air-conditioning system includes a heat-source device that includes a compressor and a heat-source-side heat exchanger, a relay device that includes a pump and an intermediate heat exchanger, and a plurality of indoor units that each include a load-side heat exchanger. The air-conditioning system includes a refrigerant circuit through which refrigerant circulates and a heat medium circuit through which a heat medium circulates. The air-conditioning system includes a flow rate detection unit configured to detect flow rate information associated with a flow rate of a heat medium that flows through each of the plurality of indoor units and a controller configured to control the compressor and the pump. The controller controls operation of at least either the compressor or the pump on the basis of the flow rate information detected by the flow rate detection unit.

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 dose 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: An air-conditioning apparatus includes: a plurality of outdoor units each including a compressor and an outdoor heat exchanger, refrigerant flowing through the plurality of outdoor units; an indoor unit including an indoor heat exchanger, a heat medium flowing through the indoor unit; a plurality of relay devices to which the plurality of outdoor units are connected independently, and to which the indoor unit is connected, each of the plurality of relay devices including a heat medium heat exchanger configured to exchange heat between the refrigerant and the heat medium; and a controller configured to control action of the plurality of outdoor units, the indoor unit, and the plurality of relay devices, wherein the controller includes a defrost determination unit configured to determine necessity for a defrosting operation, a load determination unit configured to compare, in a case where the defrosting operation is necessary, an indoor unit total load with an outdoor unit total capacity, and an equipment contr

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: 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: 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: 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 apparatus includes a heat source side unit configured to heat or cool a heat medium used as a heat-conveying medium, an air handling side heat exchanger that exchanges heat between outside air that is sent into a building and the heat medium, and an indoor side heat exchanger that exchanges heat between indoor air and the heat medium. The heat source side unit, the air handling side heat exchanger, and the indoor side heat exchanger are connected by piping to each other to form a heat medium cycle circuit through which the heat medium circulates. In the heat medium cycle circuit, a portion of the heat medium heated or cooled by the heat source side unit flows into the indoor side heat exchanger after having passed through the air handling side heat exchanger.

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 heat pump system includes a refrigerant circuit in which a compressor, a refrigerant flow path included in a heat medium heat exchanger, an expansion valve, and a heat source side heat exchanger are connected, the heat medium heat exchanger including the refrigerant flow path and a heat medium flow path; a heat medium feed path connected to the heat medium flow path included in the heat medium heat exchanger; an indoor unit connected to the heat medium feed path and configured to condition air inside a room; a room temperature sensor configured to detect an indoor temperature in the room; a heat medium temperature sensor configured to detect a temperature of a heat medium that flows into the indoor unit; and a controller configured to control the refrigerant circuit or the indoor unit by using a set temperature in the room.

Abstract: An air-conditioning apparatus includes a heat medium circulation circuit and a heat-source-side refrigerant circulation circuit. In the heat medium circulation circuit, a pump configured to pressurize a heat medium that contains water or brine, an indoor heat exchanger configured to exchange heat between an indoor air and the heat medium, and a flow control device installed corresponding to the indoor heat exchanger and configured to control a flow rate of the heat medium passing through the indoor heat exchanger are connected by a pipe to circulate the heat medium therein. A plurality of the indoor heat exchangers are installed in respective indoor units. Each of the indoor units includes a detection device configured to detect a physical quantity related to a heat quantity involved in heat exchange of the indoor heat exchanger, and is configured to perform communication by a signal containing data on detection of the detection device.

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.

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 system includes: a plurality of indoor units each configured to condition air in a target space; and an outdoor unit connected to the plurality of indoor units. Each of the plurality of indoor units has a surface temperature measuring device configured to measure a surface temperature of an object in the target space. When a total of capacities requested by the plurality of indoor units is larger than a capacity of the outdoor unit, each of the plurality of indoor units performs a process corresponding to a change amount of the surface temperature per unit time.

Abstract: An air-conditioning system includes a heat-source device that includes a compressor and a heat-source-side heat exchanger, a relay device that includes a pump and an intermediate heat exchanger, and a plurality of indoor units that each include a load-side heat exchanger. The air-conditioning system includes a refrigerant circuit through which refrigerant circulates and a heat medium circuit through which a heat medium circulates. The air-conditioning system includes a flow rate detection unit configured to detect flow rate information associated with a flow rate of a heat medium that flows through each of the plurality of indoor units and a controller configured to control the compressor and the pump. The controller controls operation of at least either the compressor or the pump on the basis of the flow rate information detected by the flow rate detection unit.