An HVAC system includes a heating element, a discharge air temperature sensor, and a return air temperature sensor. A controller of the HVAC system determines that the HVAC system has been operating in the heating mode for at least a predefined amount of time. The controller receives measurements of the discharge air temperature and the return air temperature. A temperature rise value is determined using the discharge air temperature and return air temperature. If the temperature rise value is less than a predefined minimum threshold value, the controller determines that a first fault of the HVAC system is detected and provides a corresponding alert. If the temperature rise value is greater than a predefined maximum threshold value, the controller determines that a second fault of the HVAC system is detected and provides a corresponding alert.

An HVAC system includes an evaporator coil and a compressor fluidly coupled to the evaporator coil. A condenser coil is fluidly coupled to the compressor. The condenser coil includes at least one condenser circuit fluidly coupled between a discharge line and an exit manifold. A sub-cool circuit is fluidly coupled between the exit manifold and a liquid line. A first temperature sensor is disposed at an entrance to the sub-cool circuit. A second temperature sensor is disposed at an exit to the sub-cool circuit. An HVAC controller is operatively coupled to the first temperature sensor and the second temperature sensor. The HVAC controller is configured to determine a temperature difference across the sub-cool circuit.

A heat pump configured by connecting a circuit including a variable capacity compressor, a condenser, an expansion valve, and an evaporator through a closed refrigerant line, includes a condenser fan, an evaporator fan, a refrigerant amount adjusting means for charging or recovering a refrigerant in or from the circuit, and a controller. Roles of the controller include setting a target pressure inside an outdoor heat exchanger y referring to an outside temperature and a load, setting a target pressure inside an indoor heat exchanger by referring to an inside temperature and a set temperature, setting a target sub-cooling degree and a target super-heating degree, and controlling both of the fans to either adjust temperature or adjust pressure.

The present application provides apparatus (15) for connection to an HVAC-R system during maintenance or commissioning. The apparatus includes a plurality of ports (16, 17, 18) for fluid connection to the HVAC-R system and to maintenance apparatus, for example a refrigerant tank, a refrigerant recovery unit and/or a vacuum pump. The apparatus also includes a plurality of fluid connections (20) between the plurality of ports, each of the plurality of fluid connections having an electrically actuatable valve (21) to open and close the fluid connection. The apparatus also includes a control unit configured to control each of the electrically actuatable valves to configure the plurality of fluid connections.

An air conditioner and a fluid filling method for an air conditioner are provided. The method may include operating, by the air conditioner, in a fluid supply mode, to fill a group of pipes with a fluid, such as water, determining whether an amount of the fluid in the group of pipes is appropriate while continuously filling the group of pipes with the fluid, and outputting, by an output device, information indicating that filling of the fluid has been completed when it is determined that the amount of the fluid is appropriate. The fluid supply mode may include a first fluid supply mode in which fluid is supplied while the outdoor unit is stopped, and a second fluid supply mode in which the fluid is supplied while the outdoor unit is operated.

An HVAC system includes a heating element, a discharge air temperature sensor, and a return air temperature sensor. A controller of the HVAC system determines that the HVAC system has been operating in the heating mode for at least a predefined amount of time. The controller receives measurements of the discharge air temperature and the return air temperature. A temperature rise value is determined using the discharge air temperature and return air temperature. If the temperature rise value is less than a predefined minimum threshold value, the controller determines that a first fault of the HVAC system is detected and provides a corresponding alert. If the temperature rise value is greater than a predefined maximum threshold value, the controller determines that a second fault of the HVAC system is detected and provides a corresponding alert.

A transport refrigeration system includes a compressor, a heat rejection heat exchanger, a flash tank, an expansion device and a heat absorption heat exchanger arranged in a serial refrigerant flow order to circulate a refrigerant; a controller configured to: determine a presence of at least one condition of the transport refrigeration system; and initiate a low refrigerant charge detection process in response to detecting the presence of the at least one condition of the transport refrigeration system.

A purge system for removing non-condensables from a chiller system includes a purge chamber, a plurality of carbon beds fluidly connected to the purge chamber into which a flow of refrigerant and non-condensables is selectably directed from the purge chamber to remove the non-condensables therefrom. A vent line is fluidly connected to the plurality of carbon beds to dispose of the collected non-condensables, and a heater is operably connected to the plurality of carbon beds to selectably heat one or more of the carbon beds of the plurality of carbon beds to release refrigerant therefrom and direct the released refrigerant to the purge chamber.

Efficiency in refrigerant charging work is addressed when a recovered refrigerant recovered from a first heat source unit is to be charged to a second heat source unit. A refrigerant charging method is a charging method used when a first heat source unit of an already installed refrigeration cycle apparatus in which a refrigeration cycle is to be performed by a refrigerant that circulates is to be replaced with a second heat source unit. The refrigerant charging method includes recovering a first refrigerant from an already installed refrigeration cycle apparatus and obtaining a recovered refrigerant and charging the recovered refrigerant and charging a second refrigerant whose composition differs from the composition of the recovered refrigerant to the refrigeration cycle apparatus after renewal that includes the second heat source unit.

Efficiency in refrigerant charging work is addressed when a refrigerant recovered from the first heat source unit is to be charged to a second heat source unit. In a refrigerant charging method in which a first heat source unit of an already installed refrigeration cycle apparatus in which a refrigeration cycle is to be performed by a refrigerant that circulates is replaced with a second heat source unit, transferring the refrigerant from the first heat source unit to the second heat source unit is included. In addition, the method includes measuring the weight of the refrigerant that is transferred from the first heat source unit to the second heat source unit.