An HVAC system includes a variable-speed compressor which compresses refrigerant flowing through the HVAC system, a blower which provides a flow of air through the HVAC system at a controllable flow rate, and a controller communicatively coupled to the variable-speed compressor and the blower. The controller receives a demand request, which includes a command to operate the HVAC system at a predefined setpoint temperature. In response to receiving the demand request, a setpoint temperature associated with the HVAC system is adjusted to the predefined setpoint temperature. A speed of the variable-speed compressor is decreased to a low-speed setting. Based on the decreased speed of the variable-speed compressor, an air-flow rate is determined to provide by the blower. The controllable flow rate of the flow of air provided by the blower is adjusted based on the determined air-flow rate.

An insulated icemaking compartment is provided in the fresh food compartment of a bottom mount refrigerator. The icemaking compartment may be integrally fowled with the liner of the fresh food compartment, or alternatively, may be modular for installation anywhere in the fresh food compartment. A removable bin assembly with a front cover normally seals the icemaking compartment to maintain the temperature in the compartment. A cold air duct formed in the rear wall of the refrigerator supplies cold air from the freezer compartment to the icemaking compartment. A return air duct directs a portion of the air from the icemaking compartment back to the freezer compartment. An air vent with a damper in the icemaking compartment directs another portion of air into the fresh food compartment.

A control method of a transcritical carbon dioxide composite heat pump system is disclosed, wherein the transcritical carbon dioxide composite heat pump system includes: a CO.sub.2 main circuit compressor, an air-cooling-air-cooling recombiner, a supercooling-evaporation recombiner, an evaporator and a CO.sub.2 auxiliary compressor; wherein the air-cooling-air-cooling recombiner comprises a CO.sub.2 main circuit, a CO.sub.2 auxiliary circuit and a water circuit; the supercooling-evaporation recombiner comprises a CO.sub.2 main circuit supercooling section and a CO.sub.2 auxiliary circuit evaporation section. The present invention includes two working modes according to the return water temperature, so that the unit has a wider application range and meets daily needs. There is only one heat exchanger for refrigerant and water. Compared with the three water and refrigerant heat exchangers in the conventional transcritical CO.sub.2 composite heat pump, the circulating water circuit is a single circuit with one inlet and one outlet.

A system may include a compressor, a first heat exchanger, a first working fluid flow path, and a second working fluid flow path. The first heat exchanger receives working fluid discharged from the compressor. The first working fluid flow path may receive working fluid from the first heat exchanger and may include a second heat exchanger and a first control valve that is movable between a first position allowing fluid flow through the second heat exchanger and a second position restricting fluid flow through the second heat exchanger. The second working fluid flow path may receive working fluid from the first heat exchanger and may include a third heat exchanger and a second control valve that is movable between a first position allowing fluid flow through the third heat exchanger and a second position restricting fluid flow through the third heat exchanger.

A thermal management system that include an electronic circuit boards having at least two circuit boards with a space in between and further includes one or more air tubes or conduits. The electronic circuit board and air tubes are configured for drawing air into the space to facilitate cooling of the electronic circuit board concurrent with cooling of a heat sink of a heat pump connected with the electronic circuit board. The system can further include a partition to isolate airflow from the heat sink from airflow through the electronics circuit board, and can further include one or more interface components for maintaining isolation and control of air flow, improving air intake and/or supporting auxiliary components.

A control method for a refrigerator includes sensing a temperature of a storage room; operating a cool air supply at a cooling power when the sensed temperature of the storage room is equal to or above a first reference temperature; operating the cool air supply at a delay power, which is less than the cooling power, when the sensed temperature of the storage room is equal to or below a second reference temperature, which is less than the first reference temperature while the cool air supply is operating at the cooling power; and adjusting the cooling power or the delay power of the cool air supply according to the temperature of the storage room while the cool air supply is operating at the delay power, and operating the cool air supply at the determined adjusted cooling power or delay power.

A method of controlling a refrigerator includes starting a first cooling cycle to cool a first storage compartment by operating a compressor and a first fan, determining whether a start condition of a second cooling cycle to cool a second storage compartment is satisfied, operating a second fan for the second storage compartment when the start condition of the second cooling cycle is satisfied, determining whether an output change condition of the second fan is satisfied while the second fan operates, and changing a speed of the second fan when the output change condition of the second fan is satisfied.

An air conditioner, and a device and method for preventing cold air during heating of the air conditioner are provided, including: detecting an indoor ambient temperature and an outdoor ambient temperature respectively; determining whether an evaporator inner-tube temperature satisfies an evaporator inner-tube temperature condition, or whether a duration reaches an operating duration, or whether a current intensity continuously reaches a first preset current intensity threshold for a predetermined duration; when if so, starting an inner blower fan at a first preset wind speed; determining whether the evaporator inner-tube temperature satisfies the evaporator inner-tube temperature condition, or whether the current intensity continuously reaches a second preset current intensity threshold for a predetermined duration, or whether a duration, for which the inner blower fan operates at the first preset wind speed, reaches a first preset duration; and if so, switching the inner blower fan to operate at a second preset wind speed.

A control method of a refrigerator includes: determining whether a first temperature of a refrigerating compartment satisfies a first temperature condition; based the first temperature satisfying the first temperature condition, determining whether a second temperature of a freezing compartment satisfies a second temperature condition; based on the second temperature satisfying the second temperature condition, determining (i) whether a third temperature of an ice making compartment satisfies a third temperature condition and (ii) whether a driving time for ice making has passed; maintaining operation of a compressor while determining (i) whether the second temperature satisfies the second temperature condition, (ii) whether the third temperature satisfies the third temperature condition, and (iii) whether the driving time has passed; and stopping operation of the compressor based on at least one of (i) a determination that the third temperature satisfies the third temperature condition or (ii) a determination that the driving time has passed.

An HVAC system includes a controller communicatively coupled to a subcool sensor, an outdoor temperature sensor, a compressor, and a blower of the HVAC system. For a first period of time, the controller periodically determines subcool values. For each determined subcool value, a corresponding compressor speed, outdoor temperature, and blower speed are determined. A baseline database is generated with baseline values associated with normal operation of the HVAC system. Following the first period of time, subcool values are determined based on the subcool signal. For each subcool value, a corresponding compressor speed, outdoor temperature, and blower speed are determined. The controller determines whether each subcool value satisfies a criteria based on the baseline database. If the criteria are not satisfied for at least a threshold time, the system is determined to be operating under a fault condition, and a corresponding alert is transmitted.