The present invention provides a control system for managing lubricant levels in tandem compressor assemblies of a heating, ventilation, and air conditioning (HVAC) system. In transitioning from a partial load that operates a first compressor but not a second compressor of a tandem assembly to a full load that operates both the first and the second compressor, a controller of the HVAC system turns OFF both compressors of the tandem compressor assembly to allow time for lubricant levels to equalize between the first and the second compressor.

A refrigerator including a refrigerator body including a refrigerating compartment and a freezing compartment, a refrigerating compartment cooling circuit including a refrigerating compartment compressor for compressing refrigerant, a refrigerating compartment condenser, a refrigerating compartment expansion unit, and a refrigerating compartment evaporator for causing the refrigerant to exchange heat with the refrigerating compartment; a freezing compartment cooling circuit including a freezing compartment compressor for compressing refrigerant, a freezing compartment condenser, a freezing compartment expansion unit, and a freezing compartment evaporator; a refrigerating compartment temperature sensor; a freezing compartment temperature sensor; and a control unit for controlling the refrigerating compartment compressor and the freezing compartment compressor to be concurrently operated so as to proceed to a concurrent operation mode when the refrigerating compartment and the freezing compartment are under a concurrent cooling condition, and for controlling one or both of the refrigerating compartment compressor and the freezing compartment compressor to be operated so as to proceed to a selective operation mode in consideration of a previous operation state when the refrigerating compartment and the freezing compartment are under a selective cooling condition.

An energy recovery apparatus, for use in a refrigeration system, comprises a first nozzle, a second nozzle, a turbine, a discharge port, and a housing. The first nozzle comprises a first passageway which is adapted to constitute a portion of a refrigerant flow path when the refrigeration system is operated in a first mode. The second nozzle comprises a second conduit which is adapted to constitute a portion of the flow path when the refrigeration system is operated in a second mode. The turbine is positioned to be driven by refrigerant discharged from either or both of the first and second passageways. The discharge port is adapted to permit refrigerant to flow out of the energy recovery apparatus. The discharge port of the energy recovery apparatus is downstream of the turbine. The turbine is within the housing.

A system includes a variable-capacity compressor operable at a first capacity and at a second capacity that is higher than the first capacity and an outdoor-air-temperature sensor. A control module receives a demand signal from a thermostat and operates the variable-capacity compressor in a first mode when communication with the outdoor-air-temperature sensor has not been interrupted and in a fault mode when communication with the outdoor-air-temperature sensor has been interrupted. In the first mode, the control module switches the variable-capacity compressor between the first capacity and the second capacity based on the demand signal and the outdoor-air-temperature data. In the fault mode, the control module operates the variable-capacity compressor by operating the variable-capacity compressor at at least one of the first capacity and the second capacity based on the demand signal.

An embodiment of a climate control system includes an indoor unit including a first heat exchanger to transfer heat between a refrigerant and an airflow provided to a conditioned space. In addition, the system includes an outdoor unit that further includes a second heat exchanger to transfer heat between the refrigerant and an outdoor environment and a compressor to circulate the refrigerant through the first and second heat exchangers. Further, the system includes a thermostat to determine a relative humidity of the conditioned space and to output a dehumidification signal in response to a determination that the relative humidity is above a threshold. Still further, the system includes an electrical switch coupled to the indoor and outdoor units that is actuatable based on the dehumidification signal to conduct electrical current from the indoor unit to the outdoor unit to increase a speed of the compressor.

A refrigerator includes: a storage chamber configured to be maintained at a temperature above zero degrees Celsius; an evaporator disposed in a duct that is fluidly connected to the storage chamber; a compressor; a valve disposed in a flow path which connects the compressor to the evaporator; a first fan configured to drive air that is cooled by the evaporator to the storage chamber; and a controller. The controller is configured to: control at least one of the compressor or the valve to supply a refrigerant to the evaporator based on the temperature of the storage chamber, and delay operation of the first fan for a preset first reference period of time after the at least one of the compressor or the valve began supplying the refrigerant to the evaporator.