Provided is an air conditioning apparatus that sufficiently raises the temperature of hot air to be blown out when receiving a request for high-temperature air temporarily raising the temperature of the hot air. A first use side unit includes a first use side heat exchanger and a first use side fan. A second use side unit includes a second use side heat exchanger and a second use side fan. When the first use side unit receives a request for the high-temperature air and the second use side unit receives no request for the high-temperature air, the air conditioning apparatus shifts to a mode that performs control to reduce the airflow volume of the second use side fan or make the airflow volume of the second use side fan zero such as reducing the number of revolutions of the second use side fan in another room by 40 rpm.

An air-conditioning unit that is able to suppress ignition at an electric heater even when leakage of refrigerant occurs while a low-GWP refrigerant is used is provided. In an outdoor unit (20) including a casing (60), a compressor (21) provided inside the casing (60) and configured to compress refrigerant containing 1,2-difluoroethylene, and a drain pan heater (54) provided inside the casing (60), an electric power consumption of the drain pan heater (54) is lower than or equal to 300 W.

A refrigeration cycle apparatus (1) is capable of performing a refrigeration cycle using a small-GWP refrigerant. The refrigeration cycle apparatus (1) includes a refrigerant circuit (10) and a refrigerant enclosed in the refrigerant circuit (10). The refrigerant circuit includes a compressor (21), a condenser (23), a decompressing section (24), and an evaporator (31). The refrigerant contains at least 1,2-difluoroethylene.

A refrigeration cycle apparatus includes a first three-way valve Each of the first three-way valve and the second three-way valve is configured to be switched independently to one of a first state In the first state, a first space is arranged in the valve chamber, the first space communicating with the first aperture and the second aperture and being separated from the third aperture. In the second state, a second space is arranged in the valve chamber, the second space communicating with the first aperture, the second aperture, and the third aperture. In the third state, a third space is arranged in the valve chamber, the third space communicating with the first aperture and the third aperture and being separated from the second aperture.

A heating control device includes an estimating unit to estimate a latent heat load of air present in a ventilation target space as a ventilation target and a heating control unit to control, in accordance with the latent heat load estimated by the estimating unit, a temperature of heating outside air by a heat exchanger to heat outside air supplied to the ventilation target space, via control of a condensation temperature of a refrigerant in the heat exchanger. The estimating unit estimates the latent heat load from ΔX, which is a value obtained by subtracting, from a target absolute humidity (X0) set by a temperature/humidity setting device to set a target humidity of an interior as the ventilation target space, an absolute humidity (Xi) of the interior detected by an indoor humidity sensor.

An air conditioner and a method for controlling an air conditioner. The method may include detecting an outlet temperature of a compressor; detecting a change in temperature of a hot water supply pipe; determining a system error based on the outlet temperature of the compressor; and determining an abnormality in an adjustment valve based on the temperature of the hot water supply pipe when a system error is determined.

The disclosed invention is a relay switch that is capable of controlling the sequence in which a multi-unit heat pump system where the relay device determines which of the units act as primary and which a secondary. The disclosed switch is capable of reconfiguring the sequencing with a mere flip of a switch or a toggle of an actuator. There is a protective case enclosing the actual switch. The casing carries the dual role of insulating the switch and electrical connectors, as well as providing instructions on how to integrate the disclosed device into an existing heat pump system, as well as how to operate the device after successful integration. The wiring to the switch is accomplished via a panel of clearing marked external connectors. The switch can then operate via a mechanical or electronic actuator exposed on the surface of the protective case, or remotely via a connection module.

An air conditioner includes an outdoor unit for circulating refrigerant, a plurality of indoor units for circulating water, and a heat exchange device configured to connect the outdoor unit to the plurality of indoor units and perform heat exchange between the refrigerant and the water. The heat exchange device includes a plurality of ports to which the plurality of indoor units are connected. The air conditioner further includes a controller configured to control flow of the water between the heat exchange device and the plurality of indoor units, and to search pipes respectively connected to the plurality of ports. The controller can control the flow of water such that water at a first temperature flows to some of the plurality of ports and the water at a second temperature lower than the first temperature flows to other some of the plurality of ports.

An air conditioner includes an outdoor unit having a compressor and an outdoor heat exchanger. A ventilator connected to the outdoor unit by refrigerant pipes allows outside air to pass through a heat exchanger and flow into an indoor space, and allows indoor air to pass through the heat exchanger and flow to an outdoor space. The ventilator includes a supply passage through which the outside air flows into the indoor space, and a discharge passage through which the indoor air is discharged to the outdoor space. The ventilaro also includes a main heat exchanger in the supply passage and a recovery heat exchanger in the discharge passage. A refrigerant distributor supplies the refrigerant from the outdoor unit to the main heat exchanger or the recovery heat exchanger, vice-versa. A reheat exchanger in the supply passage heats the air flowing therethrough.

A flow path switching mechanism (70) includes first to fourth flow paths (71, 72, 73, 74) and opening and closing mechanisms (V1, V2, V3, V4, 75, 76) that can each open and close a corresponding one of the flow paths (71, 72, 73, 74). A first connection point (C1) connecting an inflow portion of the first flow path (71) and an inflow portion of the second flow path (72) is connected to a discharge portion of a compression unit (30). A second connection point (C2) connecting an outflow portion of the first flow path (71) and an inflow portion of the third flow path (73) is connected to a gas-side end of a heat source heat exchanger (22). A third connection point (C3) connecting an outflow portion of the second flow path (72) and an inflow portion of the fourth flow path (74) is connected to a gas-side end of a second utilization heat exchanger (85, 93). A fourth connection point (C4) connecting an outflow portion of the third flow path (73) and an outflow portion of the fourth flow path (74), and a gas-side end of a first utilization heat exchanger (83) are connected to a suction portion of the compression unit (30).