Abstract: In a heat medium relay unit, a drain pan is configured to have width and depth dimensions larger than dimensions of an outer shell of a heat medium relay unit main body, the outer shell including side panels and, upper frames and, and lower frames and, and an upper end surface whose position is higher than those of upper end surfaces of the lower frames and.

Abstract: For each of a plurality of use-side heat exchangers, a plurality of heat medium flow switching devices respectively corresponding to the plurality of use-side heat exchangers are entirely or partially integrated, and the thus obtained integrated heat medium flow switching device is driven by a single driving device.

Abstract: In a case where frost is deposited a heat-source-side heat exchanger during a heating operation mode, an air-conditioning apparatus executes either a “heat recovery defrosting operation mode” using a heat capacity held in a heat medium or a “bypass defrosting operation mode” not using the heat capacity held in the heat medium.

Abstract: An air-conditioning apparatus includes a first branch unit, a fourth flow control device arranged in each of a plurality of pipes split from a first connection pipe side and connected to each indoor-side heat exchanger, and a solenoid valve arranged in each of pipes split from a pipe connecting each fourth flow control device and each indoor-side heat exchanger. An opening degree of the fourth flow control device is controlled based on a state of refrigerant to be caused to flow into the fourth flow control device.

Abstract: All of pumps are in operation for a predetermined period of time in an air-conditioning apparatus and, after that, the number of pumps in operation is changed depending on an operation capacity for indoor units each including a use side heat exchanger.

Abstract: 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.

Abstract: Upon switching of an air-conditioning apparatus from an operation mode in which all of indoor units each including a use side heat exchanger are in non-operation to another operation mode in which at least one of the indoor units starts a cooling operation mode or a heating operation mode, a heat medium conveyed to the use side heat exchanger included in the indoor unit which has received a start instruction is cooled or heated to a predetermined temperature by a heat source side refrigerant, and after that, an air-sending device included in the indoor unit which starts the cooling operation mode or the heating operation mode is actuated.

Abstract: An air-conditioning apparatus includes a refrigerant circuit in which a compressor, a heat-source-side heat exchanger, an expansion device, and a refrigerant flow path in at least one intermediate heat exchanger are connected by a refrigerant pipe, and a heat medium circuit in which a pump, a use-side heat exchanger, and a heat-medium flow path in the at least one intermediate heat exchanger are connected by a heat-medium conveying pipe, the heat medium circuit being configured to cause a heat medium to circulate therethrough. The at least one intermediate heat exchanger comprises a plurality of intermediate heat exchangers. The plurality of intermediate heat exchangers are operative in a heating only operation mode, a cooling only operation mode, and a cooling and heating mixed operation mode in which some of the intermediate heat exchangers serve as the condenser and others of the intermediate heat exchangers serve as the evaporator.

Abstract: An air conditioning apparatus includes a refrigerant circuit in which a compressor for compressing heat source-side refrigerant, a first refrigerant channel switching device, a heat source side heat exchanger, an expansion device, and intermediate heat exchangers for performing heat exchange between the heat source-side refrigerant and a heat medium different from the heat source-side refrigerant are connected by pipes. Also, the air conditioning apparatus includes a heat medium circuit in which pumps for circulating the heat medium to be used for the heat exchange performed by the intermediate heat exchangers, a use-side heat exchanger, and channel switching devices for switching passages of the heat medium heated or cooled to the use-side heat exchanger are connected by pipes.

Abstract: In an air-conditioning apparatus, when a plurality of pumps are all operating and a heat exchange amount in use-side heat exchangers is equal to or lower than a lower limit of a thermal capacity that can be conveyed in a heat medium circuit B, before at least one of the plurality of pumps is stopped, a refrigerant flow path in the intermediate heat exchanger connected to the pump that is to be stopped is closed. Then, the at least one of the plurality of pumps is stopped, and the thermal capacity required in at least one of the use-side heat exchangers in the rest of the plurality of pumps is conveyed.

Abstract: In an air-conditioning apparatus including a plurality of indoor units connected to a heat medium converter and a plurality of remote controllers respectively provided for the indoor units, the remote controllers each include a temperature sensor that detect a temperature of a corresponding space to be air-conditioned, and are each configured to communicate with a heat medium converter controller of the heat medium converter and an indoor unit controller of the corresponding indoor unit, transmit an instruction to start and stop an operation and data related to rotation speed of an indoor air-sending device to the corresponding indoor unit controller, and transmit the instruction to start and stop the operation, and a target temperature and a temperature detected by the temperature sensor or a difference therebetween, to the heat medium converter controller.

Abstract: An air-conditioning apparatus includes actuation control means including an actuation unit that sequentially opens heat medium flow switching devices or heat medium flow control devices on a one-by-one basis. The actuation control means performs control in such a manner that start time of driving of pumps is later than start of actuation of the heat medium flow switching devices and the heat medium flow control devices.

Abstract: An air-conditioning apparatus includes a heat medium temperature adjustment operation mode in which when the temperature of a heat medium falls outside a predetermined temperature range while a compressor and a pump are kept stopped, the compressor and the pump are driven to cause an intermediate heat exchanger to exchange heat between a refrigerant and the heat medium so that the heat medium is heated or cooled to have a temperature that falls within the temperature range.

Abstract: An air-conditioning apparatus includes a heat source-side unit including a compressor that compresses a refrigerant and a heat source-side heat exchanger, a plurality of use-side units each including a use-side heat exchanger, and a plurality of intermediate heat exchangers connected to the heat source-side unit and to the use-side units. A target determination device detects condensation status of each of the use-side units and determines whether to perform condensation suppression control. The use-side unit determined by the target determination means to be subjected to the condensation suppression control is connected to an intermediate heat exchanger for adjustment. A refrigerant circuit control device controls a temperature of the refrigerant flowing into the intermediate heat exchanger for adjustment so that the heat medium temperature T of the heat medium flowing into at least one use-side unit enters a predetermined target set temperature range.

Abstract: An air-conditioning apparatus includes a compressor, an indoor heat exchanger configured to function as a condenser or an evaporator, indoor heat exchanges each configured to function as a condenser or an evaporator, a plurality of expansion valves each provided for a corresponding one of the indoor heat exchangers each configured to adjust a flow rate of a refrigerant that flows through the corresponding indoor heat exchanger and a controller configured to control an operation capacity of the compressor and opening degrees of a plurality of expansion devices. When increasing heat exchange performance of the indoor heat exchanger, the controller increases the operation capacity of the compressor and controls the opening degree of the expansion valve corresponding to the indoor heat exchanger to decrease the flow rate of the refrigerant that flows through the indoor heat exchanger.

Abstract: An air-conditioning apparatus is provided to which, even when a heat medium leaks from a heat medium circuit for some reason and air enters the heat medium circuit, the heat medium circuit can be automatically refilled with the heat medium before a pump is heated and damaged. When it is determined that a rotational speed of a pump is higher than an upper rotational speed limit, the controller determines that the heat medium is leaking from the heat medium circuit and performs a heat-medium-introducing and air-purging control process.

Abstract: An air-conditioning apparatus according to the present invention includes at least indoor heat exchangers. In response to a request to increase heat exchange performance from the indoor heat exchanger, the air-conditioning apparatus decreases a heat exchange capacity of an outdoor heat exchanger and controls an opening degree of an expansion valve corresponding to the indoor heat exchanger a to decrease a flow rate of a refrigerant that flows through the indoor heat exchanger.

Abstract: A valve body in each of heat medium flow switching devices has an open portion. When the length from a connection between a first passage pipe and a third passage pipe to a connection between a second passage pipe and the third passage pipe is defined as a casing passage width, a valve body passage width of the open portion in a direction substantially perpendicular to the axis of the valve body is smaller than the casing passage width.