Disclosed is a gas detector system for a refrigerated interior volume of a transportation refrigeration unit (TRU), the system having: a gas detector that defines an enclosure, the enclosure defines a chamber therein, the cover including a chamber opening, and an infrared (IR) sensor within the chamber; and a heater adjacent to or within the enclosure, the heater configured to reduce moisture within the chamber and/or prevent moisture from accumulating from within the chamber during a refrigeration cycle.

A defrosting system includes an RF signal source, two electrodes proximate to a cavity within which a load to be defrosted is positioned, a transmission path between the RF signal source and the electrodes, and an impedance matching network electrically coupled along the transmission path between the output of the RF signal source and the electrodes. The system also includes power detection circuitry coupled to the transmission path and configured to detect reflected signal power along the transmission path. A system controller is configured to modify, based on the reflected signal power, a value of a variable passive component of the impedance matching network to reduce the reflected signal power. The impedance matching network may be a single-ended network or a double-ended network.

There is provided a sublimation defrosting method for removing a frost layer adhering to a cooling surface for cooling a to-be-cooled gas, including a heating/temperature-rising step of heating an adhesion portion of the cooling surface, to which the frost layer adheres, to rise a temperature of the adhesion portion by a heat source located on an adhesion portion side with respect to the frost layer, under a temperature condition below a melting point of the frost layer.

An improved heat pump apparatus configured to transfer heat by circulating a refrigerant through a cycle of evaporation and condensation without the need to run a defrost cycle—the No-Frost Heat Pump (NFHP)—is provided. The NFHP is configured with a four-way valve, a suction accumulator, and a compressor to pump and exchange a refrigerant between two heat exchange coil/coils—an outdoor heat exchange coil/coil (also known as the source coil) and an indoor heat exchange coil/coil (also known as the load coil)—in order to exchange heat between the indoor/outdoor heat exchange coils. The NFHP is further configured with a means for controlling hot gas discharge—the means comprising a discharge valve or a discharge gas injection valve configured to inject refrigerant into the outdoor heat exchange coil inlet/source coil, thereby preventing the formation of ice/frost on the surface of the coil while operating in heating mode at low outdoor ambient temperatures.

In an air-conditioning, first flow passage selection device and a second flow passage selection device each are a constant-energized-type three-way valve in which a position of a main valve can be fixed in a de-energized state. When the refrigerant circuit is switched to the cooling circuit by a flow switching device, when at least one of the first flow passage selection device and the second flow passage selection device is in a de-energized state, the first flow passage selection device or the second flow passage selection device in the de-energized state is configured to output refrigerant discharged from the compressor and input therein via the flow switching device and the bypass pipe to a corresponding one of an upper-side outdoor heat exchanger and a lower-side outdoor heat exchanger.

A method of controlling the temperature in cavities of a refrigerator (10) cooled by a refrigeration circuit having a compressor (18) and an evaporator (32) includes the steps of: monitoring the duty cycle of the compressor (18); determining whether the duty cycle is below a threshold; determining whether the temperature of the evaporator (32) is above a threshold; and if the duty cycle is below the threshold and if the evaporator temperature is above a threshold, activating the refrigeration circuit to start cooling of at least one of the refrigerator cavities. A refrigeration appliance (10) with a controller that activates the refrigeration circuit based on the monitored duty cycle of the compressor (18) and the evaporator temperature is also provided.

A ventilation unit for a freezer chamber, with a conduit and at least one heating element, wherein in the conduit, at least in sections, an air-permeable filler material is disposed, as well as a freezer chamber with such a ventilation unit as well as methods for operating such ventilation unit.

The present invention provides a control method of a refrigerator, comprising: a first defrosting step of defrosting an evaporator and terminating the defrosting when the evaporator reaches a first temperature; a step of detecting pressure difference by means of a differential pressure sensor for measuring pressure difference between a first thru-hole, disposed between the evaporator and an inlet through which air flows in from a storage compartment, and a second thru-hole disposed between the evaporator and an outlet through which the air is discharged into the storage compartment; and a second defrosting step of additionally defrosting the evaporator if the measured pressure difference is greater than a configured pressure.

A dual redundant cooling system for a container is provided. The dual redundant cooling system includes a first cooling unit and a second cooling unit. The first cooling unit is positioned in a first cabinet attached to the container. The first cooling unit includes a first controller operating a first cooling loop to cool an interior of the container. The second cooling unit is positioned in a second cabinet attached to the container and adjacent the first cabinet. The second cooling unit includes a second controller operating a second cooling loop to cool the interior of the container. The first cooling unit and the first cooling loop are separate from the second cooling unit and the second cooling loop. The first controller and the second controller communicate a switch signal between each other so that either the first cooling unit is a primary cooling unit operating the first cooling loop or the second cooling unit is the primary cooling unit operating the second cooling loop. The switch signal switching the primary cooling unit. The system interface box positioned in the second cabinet and connected to the first cooling unit and the second cooling unit. The system interface box has a first switch adapted to power on or power off the first cooling unit and a second switch adapted to power on or power off the second cooling unit.

An air conditioner is provided that may include a defrosting bypass valve disposed at a defrosting bypass pipe having a first end connected to a middle point of the outdoor heat exchanger and a second end connected to an inlet pipe of a compressor, and a processor configured to open and close the defrosting bypass valve according to a temperature of a refrigerant in an outdoor heat exchanger. At a beginning of a defrosting operation, the processor may open the defrosting bypass valve to bypass a portion of the refrigerant in the outdoor heat exchanger to the inlet pipe of the compressor, and if the temperature of the refrigerant in the outdoor heat exchanger exceeds a predetermined temperature, the processor may close the defrosting bypass valve, thereby achieving defrosting performance at an early stage of the defrosting operation.