A refrigerant control system includes: a charge module configured to determine an amount of refrigerant that is present within a refrigeration system of a building; a leak module configured to diagnose that a leak is present in the refrigeration system based on the amount of refrigerant; and at least one module configured to take at least one remedial action in response to the diagnosis that the leak is present in the refrigeration system.

A method for operating a heat pump (20; 300) includes operating in a cooling mode wherein heat is absorbed by refrigerant in the indoor heat exchanger (26) and rejected by refrigerant in the outdoor heat exchanger (24). The heat pump switches to operation in a heating mode wherein heat is rejected by refrigerant in the indoor heat exchanger, heat is absorbed by refrigerant in the outdoor heat exchanger, and there is an ejector (60) motive flow and ejector secondary flow. In the heating mode a refrigerant pressure (PH) or temperature (TL) is measured and, responsive to the measured refrigerant pressure or temperature, at least one of a fan speed is changed and a needle (132) of the ejector is actuated.

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 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.

A refrigerant control system includes: a charge module configured to determine an amount of refrigerant that is present within a refrigeration system of a building; a leak module configured to diagnose that a leak is present in the refrigeration system based on the amount of refrigerant; and at least one module configured to take at least one remedial action in response to the diagnosis that the leak is present in the refrigeration system.

A method for operating a heat pump (20; 300) includes operating in a cooling mode wherein heat is absorbed by refrigerant in the indoor heat exchanger (26) and rejected by refrigerant in the outdoor heat exchanger (24). The heat pump switches to operation in a heating mode wherein heat is rejected by refrigerant in the indoor heat exchanger, heat is absorbed by refrigerant in the outdoor heat exchanger, and there is an ejector (60) motive flow and ejector secondary flow. In the heating mode a refrigerant pressure (P.sub.H) or temperature (T.sub.L) is measured and, responsive to the measured refrigerant pressure or temperature, at least one of a fan speed is changed and a needle (132) of the ejector is actuated.

The present disclosure relates to a novel method for operating and controlling a vapor-compression cycle. The method of the present disclosure provides that a turbine-based expander in a heat pump model can achieve greater COP benefit in cooling than heating. Further, phase separation and an evaporator bypass are implemented within the turbine-based expander. Phase separation leads to successful energy recovery and compressor superheat control.

An air conditioning system provided which has: an outdoor device including at least a compressor and a first heat exchanger; an air handling device including an air supply fan and a second heat exchanger; an expansion valve; and a control section, wherein the compressor, the first heat exchanger, the expansion valve, and the second heat exchanger are sequentially connected in an annular shape to form a refrigerant circuit in which refrigerant circulates, and the control section adjusts a rotation speed of the air supply fan and/or a degree of opening of the expansion valve based on information including a temperature detection value of refrigerant on each of one end side and the other end side of the second heat exchanger, a temperature detection value of air toward the second heat exchanger, and a temperature detection value of air heat-exchanged by the second heat exchanger.

An air conditioner including a compressor, an outdoor heat exchanger, an expansion valve, an indoor heat exchanger, a first fan, a second fan, and a cooling/heating conversion device. The compressor is configured to compress a refrigerant and including a first compressor and a second compressor. The outdoor heat exchanger is configured to exchange heat of the refrigerant with outdoor air, and includes a first and second heat exchanger. The expansion valve is configured to expand a refrigerant. The indoor heat exchanger is configured to exchange heat of the refrigerant with indoor air. The first fan and the second fan correspond to the first heat exchanger and the second heat exchanger, respectively. The cooling/heating conversion device during a during a heating operation is connected in parallel to the first and second heat exchangers, and during a during a cooling operation is connected in series to the first and second heat exchangers.

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.