An air conditioning system includes a bypass passage and a cooling-heating switching mechanism. The bypass passage is configured to be at least a part of a flow passage connecting a third port to a refrigerant inlet of a compressor. A second expansion valve opens and closes the bypass passage. The cooling-heating switching mechanism includes check valves and four-way valves. The four-way valve causes a refrigerant outlet of the check valve to communicate with one of the refrigerant inlet and a refrigerant outlet of the compressor. The four-way valve causes a refrigerant inlet of the check valve to communicate with one of the refrigerant inlet and the refrigerant outlet of the compressor and causes a port to communicate with the other of the refrigerant inlet and the refrigerant outlet.

Provided is a refrigeration cycle apparatus including: a refrigeration cycle configured to circulate refrigerant; a heat exchanger unit configured to accommodate at least a heat exchanger of the refrigeration cycle; and a controller configured to control the heat exchanger unit, in which: the heat exchanger unit includes: an air-blowing fan; and a refrigerant detection unit configured to detect a concentration of leaked refrigerant and to output a detection signal to the controller; and the controller is configured to operate the air-blowing fan when detecting leakage of the refrigerant, and to stop the air-blowing fan triggered by becoming positive from negative of a temporal change of the concentration of the leaked refrigerant.

A system for air-conditioning and hot-water supply is configured to selectively perform a cooling operation and a heating operation. The system includes: an outdoor unit having a compressor and an outdoor heat exchanger; a plurality of indoor units each of which is connected to the outdoor unit and includes an indoor heat exchanger; a hot-water supply unit connected to the outdoor unit so as to be arranged in parallel to the indoor unit and including a refrigerant-water heat exchanger; and a controller configured to monitor a request for hot-water supply from the hot-water supply unit. The controller is further configured to continue a cooling operation after the request has occurred and until a predetermined condition is satisfied where the request for hot-water supply has occurred during the cooling operation at at least one of the plurality of indoor units, and then to start a heating operation.

A system for air-conditioning and hot-water supply is configured to selectively perform a cooling operation and a heating operation. The system includes: an outdoor unit having a compressor and an outdoor heat exchanger; at least one or more indoor units each of which is connected to the outdoor unit and includes an indoor heat exchanger; a hot-water supply unit connected to the outdoor unit so as to be arranged in parallel to the indoor unit and including a refrigerant-water heat exchanger; a controller configured to monitor an occurrence of a request for hot-water supply from the hot-water supply unit during the cooling operation being performed at at least one indoor unit among the at least one or more indoor units, and then to start the heating operation in accordance with the request. The controller is further configured to transmit to each of the at least one or more indoor units, which is turned on for the cooling operation, a fan-stop command to stop a fan arranged at each indoor unit.

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.

A refrigeration cycle apparatus in which a compressor, a heat-source-side heat exchanger, a decompressor, and a use-side heat exchanger are connected by pipes to allow refrigerant to be circuited as a refrigeration cycle. The refrigeration cycle apparatus includes a controller which controls an operation of each of devices. The controller sets an operation mode to a specific operation mode for determining where abnormality occurs based on states of the compressor, the heat-source-side heat exchanger, the decompressor and the use-side heat exchanger in the case where an operating state of one of a plurality of element devices to be controlled by the controller is changed from a first state to a second state, the element devices being included in the compressor, the heat-source-side heat exchanger, the decompressor and the use-side heat exchanger.

A controller for controlling an environmental condition of a building via building equipment includes a user interface configured to present information to a user, an air quality sensor configured to sense indoor air quality conditions, a communications interface configured to communicate with a server system and receive outdoor air quality data from the server system, and a processing circuit. The processing circuit is configured to generate indoor air quality data based on the sensed indoor air quality data conditions sensed by the air quality sensor, receive, via the communications interface, the outdoor air quality data from the server system, and generate one or more interfaces indicating the indoor air quality conditions and the outdoor air quality conditions based on the indoor air quality data and the outdoor air quality data and cause the user interface to display the one or more interfaces.

An air-conditioning apparatus includes at least one indoor unit with intake and blow-out ports, a refrigerant gas sensor disposed in an air flow path inside the indoor unit; and a control device. The indoor unit has an indoor fan drawing indoor air in from the intake port and blowing conditioned air out from the blow-out port, an indoor temperature sensor detecting temperature of the indoor air, an indoor-side refrigerant circuit circulating a refrigerant having a greater specific gravity when gasified than air and producing conditioned air from the indoor air, and at least one refrigerant temperature sensor detecting refrigerant temperature in the refrigerant circuit. The control device drives the indoor fan in accordance with at least one of an operation mode and a detection value of the at least one refrigerant temperature sensor, and detects refrigerant leakage using the refrigerant gas sensor.

A system includes a compressor, an indoor fan, a thermostat, an indoor fan controller, and a compressor controller. The thermostat provides first and second signals based on indoor loading. The fan controller operates the fan in low speed mode and the compressor controller operates the compressor in low capacity mode when only the first signal is asserted. The compressor controller automatically switches the compressor to high capacity mode if only the first signal remains asserted past the low capacity mode runtime. The fan controller operates the fan in high speed mode when the second signal is asserted while the first signal is still asserted. The compressor controller continues to operate the compressor in high capacity mode and the fan controller operates the fan in low speed mode after the second signal is de-asserted, until the first signal is de-asserted, at which point the fan and compressor are turned off.

A load unit includes a water circuit chamber configured to accommodate at least a part of a water circuit configured to allow water to flow therethrough, a fan, an air inlet formed at a height positioned different from that of the air inlet and configured to suck indoor air therethrough, an air outlet configured to blow indoors the air sucked through the air inlet, and an air passage formed between the air inlet and the air outlet so as to be isolated from the water circuit chamber. A load-side heat exchanger is provided in the air passage.