A method for determining a time frame for when a freezer having a compressor should be defrosted include the steps of measuring compressor cycling over time, determining a change in compressor cycling over time, and determining from the change in in compressor cycling over time determined a time frame for when the freezer should be defrosted.

A freezer and method of operating a freezer are provided with an adaptive defrost cycle. The freezer includes a controller that operates the freezer to: provide cooling to a cabinet via an evaporator during periodic operational cycles, monitor a time elapsed since a most recent defrost cycle, determine whether the time elapsed is greater than a current defrost interval, and perform a defrost cycle if so. The controller varies the current defrost interval between a first, larger time value and a second, smaller time value based on a plurality of trigger signals in response to various operating characteristics of the freezer monitored by sensors. After each defrost cycle is completed, the current defrost interval is reset to the first, larger time value.

A refrigerator includes a cabinet configured to form a first storage chamber and a second storage chamber, a first evaporator configured to cool the first storage chamber, a first fan configured to circulate air in the first storage chamber to the first evaporator and the first storage chamber, a second evaporator configured to cool the second storage chamber, a compressor configured to be connected to the first evaporator and the second evaporator, a second fan configured to circulate air in the second storage chamber to the second evaporator and the second storage chamber; a refrigerant valve configured to guide refrigerant to the first evaporator or the second evaporator, and a controller configured to perform a plurality of modes sequentially to defrost the second evaporator.

A refrigerator includes a main body defining a storage space, a cryogenic freezing compartment having an insulation space that is independent with respect to the storage space, an evaporator disposed inside the storage space to cool the storage space, and a thermoelectric module assembly disposed at one side of the cryogenic freezing compartment so that the cryogenic freezing compartment is cooled to a temperature less than that of the storage space. The thermoelectric module assembly includes a thermoelectric module, a cold sink coming into contact with a heat absorption surface of the thermoelectric module and disposed in the cryogenic freezing compartment, and a heat sink coming into contact with a heat generation surface of the thermoelectric module. The heat sink is cooled by introducing a refrigerant supplied to the evaporator.

A control device controls a heating capacity during a heating operation and a defrosting capacity during a defrosting operation. The defrosting capacity of the first refrigeration cycle unit is determined to fall within a range satisfying a first determination condition and within a range satisfying a second determination condition. The first determination condition is a condition that a sum of a load capacity of a load device when the first defrosting start condition is satisfied, and the defrosting capacity of the first refrigeration cycle unit does not exceed the heating capacity of a second refrigeration cycle unit. The second determination condition is a condition that a sum of an inter-unit defrosting interval and a defrosting period of the first refrigeration cycle unit does not exceed a shortest defrosting interval of the second refrigeration cycle unit.

The present disclosure relates to a refrigerator. According to an embodiment of the present disclosure, the refrigerator comprises: an evaporator; a defrost heater; a temperature sensor to sense a temperature around the evaporator; and a controller to control the defrost heater. In response to reaching a defrost operation starting point, the controller is configured to perform a defrost operation mode, perform a continuous operation mode, in which the defrost heater continuously turns on, and a pulsed operation mode, in which the defrost heater switches between on and off, based on the defrost operation mode, wherein in response to performing the pulsed operation mode, the controller is configured to change the ON duration or power level of the defrost heater. Accordingly, defrosting efficiency may be improved, and power consumption may be reduced.

A defrost or thaw measuring device has a dumbbell or hourglass-shaped rotatable compartment with a cavity, the cavity being partly filled with at least two phase change materials having different melting points. The measuring device may determine the time period of thawing at two or more temperature intervals in the refrigeration space.

A defrost or thaw measuring device has a dumbbell or hourglass-shaped rotatable compartment with a cavity, the cavity being partly filled with at least two phase change materials having different melting points. The measuring device may determine the time period of thawing at two or more temperature intervals in the refrigeration space.

A refrigerator includes a storage compartment; a first flow path separated from the storage compartment; an evaporator provided on the first flow path to cool air; a compressor configured to discharge a refrigerant to the evaporator; a blower fan configured to discharge air of the first flow path to the storage compartment; a defrost heater provided on the first flow path to heat the evaporator; a second flow path separated from the first flow path; a defrost fan configured to suction air of the first flow path into the second flow path; and a controller configured to alternately perform a cooling operation and a defrosting operation, configured to operate the compressor and the blower fan during the cooling operation, configured to operate the defrost heater and the defrost fan during the defrosting operation, and configured to vary a rotational speed of the defrost fan.

A method for controlling a refrigerator, according to an embodiment of the present invention, comprises: a step in which it is determined whether a period of defrosting (POD) for defrosting a freezing compartment and a deep-freezing compartment has elapsed; a step in which, when it is determined that the period of defrosting has elapsed, a deep cooling operation for cooling at least one from among the temperature of the deep-freezing compartment and the temperature of the freezing compartment to be lower than a control temperature is performed; and a step in which, when the deep cooling operation finishes, a defrosting operation for defrosting the freezing compartment and the deep-freezing compartment is performed. When the defrosting operation starts, a freezing compartment valve is closed so as to prevent cold air from flowing to a freezing compartment evaporator and a heat sink, and at least a portion of a freezing compartment defrosting section and at least a portion of a deep-freezing compartment defrosting section overlap with each other.