An HVAC system includes an outdoor heat exchanger. A first indoor heat exchanger is fluidly coupled to the outdoor heat exchanger and disposed in a first zone. A second indoor heat exchanger is fluidly coupled to the outdoor heat exchanger and disposed in a second zone. A compressor is fluidly coupled to the outdoor heat exchanger, the first indoor heat exchanger, and the second indoor heat exchanger. A first circulation fan is positioned to circulate air around the first indoor heat exchanger and a second circulation fan is positioned to circulate air around the second indoor heat exchanger. A first zone controller is electrically coupled to the first indoor heat exchanger. The first zone controller is configured to measure a temperature in the first zone, compare the measured temperature to a setpoint temperature of the first zone, and responsive to a difference between the measured temperature and the setpoint temperature, adjust a speed of the first circulation fan independent of the speed of the second circulation fan.

A refrigerant circuit of a refrigeration device, such as a household refrigeration device, has the following connected in series between a pressure connection and a suction connection of a compressor: a condenser, a first throttle point, a first evaporator for cooling a first storage chamber, a second throttle point. At least one of the first and second throttle points are adjusted to control the pressure in the first evaporator. The refrigerant circuit has a first branch with the first throttle point, the first evaporator and the second throttle point, and at least one second branch, parallel to the first branch, in which a third throttle point, a second evaporator arranged in thermal contact with a second storage chamber and a fourth throttle point are connected in series. At least one of the third and fourth throttle points can be adjusted to control the pressure in the second evaporator.

A refrigerant circuit of a refrigeration device, such as a household refrigeration device, has the following connected in series between a pressure connection and a suction connection of a compressor: a condenser, a first throttle point, a first evaporator for cooling a first storage chamber, a second throttle point. At least one of the first and second throttle points are adjusted to control the pressure in the first evaporator. The refrigerant circuit has a first branch with the first throttle point, the first evaporator and the second throttle point, and at least one second branch, parallel to the first branch, in which a third throttle point, a second evaporator arranged in thermal contact with a second storage chamber and a fourth throttle point are connected in series. At least one of the third and fourth throttle points can be adjusted to control the pressure in the second evaporator.

A vapor compression refrigeration system has a main refrigerant circuit having a primary compressor group, a gas cooler or condenser, an expansion device, a liquid receiver, and at least one evaporator. An emergency circulation duct fluidically connects the liquid receiver to the main circuit to allow a flow of refrigerant from the liquid receiver to the gas cooler. An emergency compressor group in the emergency circulation duct is activatable when pressure inside the liquid receiver or in the duct upstream of the emergency compressor group meets or exceeds a predefined emergency pressure threshold. An uninterruptible power supply powers the emergency compressor group and expansion device during a shutdown of the refrigeration system. When pressure inside the liquid receiver or in the duct upstream of the emergency compressor group equals or exceeds the predefined emergency pressure threshold, an emergency circulation of refrigerant fluid is activated through the emergency circulation duct.

A vapor compression refrigeration system has a main refrigerant circuit having a primary compressor group, a gas cooler or condenser, an expansion device, a liquid receiver, and at least one evaporator. An emergency circulation duct fluidically connects the liquid receiver to the main circuit to allow a flow of refrigerant from the liquid receiver to the gas cooler. An emergency compressor group in the emergency circulation duct is activatable when pressure inside the liquid receiver or in the duct upstream of the emergency compressor group meets or exceeds a predefined emergency pressure threshold. An uninterruptible power supply powers the emergency compressor group and expansion device during a shutdown of the refrigeration system. When pressure inside the liquid receiver or in the duct upstream of the emergency compressor group equals or exceeds the predefined emergency pressure threshold, an emergency circulation of refrigerant fluid is activated through the emergency circulation duct.

A heat exchanger group includes a first heat exchanger, a second heat exchanger, and a third heat exchanger. In a cooling operation, refrigerant discharged from the compressor is divided into two. One refrigerant is delivered to the second heat exchanger, and the other refrigerant is delivered to the third heat exchanger. The second heat exchanger performs heat exchange to turn the refrigerant into two-phase refrigerant. The third heat exchanger performs heat exchange to turn the refrigerant into two-phase refrigerant. The refrigerant that has flowed through the second heat exchanger and the refrigerant that has flowed through the third heat exchanger meet, and the resultant refrigerant is delivered to the first heat exchanger. The first heat exchanger performs heat exchange, so that the two-phase refrigerant turns into liquid refrigerant and flows through the first heat exchanger.

A heat exchanger group includes a first heat exchanger, a second heat exchanger, and a third heat exchanger. In a cooling operation, refrigerant discharged from the compressor is divided into two. One refrigerant is delivered to the second heat exchanger, and the other refrigerant is delivered to the third heat exchanger. The second heat exchanger performs heat exchange to turn the refrigerant into two-phase refrigerant. The third heat exchanger performs heat exchange to turn the refrigerant into two-phase refrigerant. The refrigerant that has flowed through the second heat exchanger and the refrigerant that has flowed through the third heat exchanger meet, and the resultant refrigerant is delivered to the first heat exchanger. The first heat exchanger performs heat exchange, so that the two-phase refrigerant turns into liquid refrigerant and flows through the first heat exchanger.

A heating, ventilation and air conditioning system (200) reduces energy consumption in a building (202) by turning on and off all compressors (212, 214, 216). The HVAC system (200) includes a plurality of in-flow air temperature sensors (232, 234, 236) and out-flow air temperature sensors (242, 244, 246) that respectively measure return air temperatures at inlets and supply air temperatures at outlets of fan coil units (222, 224, 226) located in rooms (203, 205, 207) of the building (202). The HVAC system (200) turns on and off all the compressor (212, 214, 216) based on the return air temperatures and the supply air temperatures.

A refrigerator includes a main body that has a storage chamber and a drying chamber; a thermoelectric module that includes a heat absorber and a heat dissipater; a cooling fan that circulates air in the storage chamber to the heat absorber and the storage chamber; a heat-dissipating fan that blows air to the heat dissipater; an air guide that has a passage for guiding air heated by the heat dissipater to the drying chamber; a heater that is disposed in the passage; and a damper that controls a flow of air in the passage between the heat-dissipating fan and the heater. Heat of the heat dissipater transfers to the drying chamber through the passage of the air guide and the damper, thereby being able to dry an object to be dried.

A portable dehumidifier includes a cabinet, a fan, a dehumidification system, and a compressor. The cabinet includes a front side and a back side opposite the front side, an airflow inlet located on a first side of the cabinet, and an airflow outlet located on a second side of the cabinet that is opposite the first side. The dehumidification system includes a secondary evaporator located proximate to the airflow inlet, a primary condenser located proximate to the airflow outlet, a primary evaporator located adjacent to the secondary evaporator, a secondary condenser located between the primary evaporator and the primary condenser, and a compressor. The fan is configured to generate an airflow that flows into the cabinet through the airflow inlet and out of the cabinet through the airflow outlet. The airflow flows through the dehumidification system in order to provide dehumidification to the airflow.