Abstract: The present invention relates to a method for defrosting a refrigerator with two evaporators, and more particularly, to a method for defrosting a refrigerator with two evaporators, in which the two evaporators are operated on the same time when defrosting time points of the two evaporators are close. Moreover, when it is intended that the freezing chamber evaporator is defrosted, after the freezing chamber temperature and the storage chamber temperature are dropped to lower limits of temperature ranges, the freezing chamber evaporator is defrosted, and when the storage chamber is operative in a kimchi fermenting mode for fermenting kimchi, it is made that the storage chamber evaporator is not defrosted even if the storage chamber evaporator reaches to the defrosting period.

Abstract: Disclosed is a refrigerator for kimchi, including a main body having at least one cooling chamber, an evaporator for cooling the cooling chamber, a compressor for supplying a refrigerant to the evaporator, a refrigerant tube for supplying the refrigerant from the compressor to the evaporator, and a valve installed in the refrigerant tube for controlling the supply of the refrigerant. The kimchi refrigerator further comprises a temperature sensor for detecting the temperature of the cooling chamber; a heater installed in the main body, heating and defrosting the evaporator; and a controller for controlling the heater to perform the defrosting operation when the temperature of the cooling chamber detected by the temperature sensor is not more than a predetermined temperature. With this configuration, a layer of frost frozen in the evaporators can be removed effectively, to thereby further enhance a cooling efficiency and save a consumed power.

Abstract: A method of temperature control in a cryogenic system, wherein the system includes a cryogenic tank. The method comprises providing a motor speed sensor which determines a motor speed, providing a pressure sensor which determines a cryogenic pressure, providing a temperature sensor in the conditioned space which measures a temperature within the conditioned space, providing a deprived integral region, and generating an overriding control signal at the proportional-integral-derivative controller when the temperature and the pressure are beyond a temperature set point and a pressure set point.

Abstract: A defrost control system for a self-defrosting refrigerator is configured to monitor a compressor load, determine whether at least a first defrost cycle is required based on the compressor load, execute at least one defrost cycle when required; and regulate the defrost cycle to conserve energy. A controller is operatively coupled to a compressor, a defrost heater, and a refrigeration compartment temperature sensor. The controller makes defrost decisions based on temperature conditions in the refrigeration compartment in light of other events, such as refrigerator door openings, completed defrost cycles, and power up events. Defrost cycles are automatically adjusted as operating conditions change, thereby avoiding unnecessary energy consumption that would otherwise occur in a fixed defrost cycle.

Abstract: An apparatus for removing deposits from a heat transfer wall of a heat exchanger. The apparatus includes a cleaning cycle control system that operates through the control system of the heat pump and eliminates the need for periodic acid cleaning of heat exchanger. The cleaning cycle control system engages a heating cycle of the heat pump to at least partially freeze the fluid adjacent to the heat transfer wall and then engages the cooling cycle of the heat pump to thaw the fluid adjacent to the heat transfer wall. The thermal expansion and contraction of the deposits on the heat transfer wall and the flow of fluids through the heat exchanger flush deposits from the heat transfer wall of the heat exchanger.

Abstract: A refrigerator has a fresh food compartment (3) adapted for maintaining the contents at a temperature above freezing. A vapour compression refrigeration system is operable in one mode so that an evaporator (7) is operated at a temperature within 10° C. of the temperature desired in the fresh food compartment (3) and a supply of air is maintained over the evaporator (7) and in to the compartment (3). The vapour compression system is used in a defrost mode in which the vapour compression refrigeration system is stopped or allowed to operate without significant heat extraction at the evaporator (7), and a supply of air above 0° C. is past over it. Operating the fresh food compartment evaporator (7) at such a high temperature (close to 0° C.) reduces the rate of frost build up and the under cooling of frost. Frost may be adequately removed by an ambient air flow without heater supplementation.

Abstract: Methods and apparatus for freezer defrost, which are particularly suited for an automated system, include the formulation of algorithms utilized for this purpose. The algorithms are included in the firmware of an embedded controller and operate the freezer defrost cycle at temperature lows for increased efficiency. An application of the freezer defrost method and apparatus is also disclosed.

Abstract: A refrigeration system for objects is disclosed. The system includes a refrigeration device and a defrost system. The refrigeration device provides a case or container defining a space for the objects, a first heat exchanger associated with the container for cooling a fluid communicating with the space to cool the objects and a second heat exchanger to receive a heat supply from an air source for warming the fluid. A system for cooling articles is also disclosed. The system includes a space configured to contain the articles, a first element to provide cooling of the articles within the space, a first coolant source to refrigerate the space by cooling the first element in a first state, and a second coolant source to elevate a temperature of the first element in a second state.

Abstract: Method and apparatus for providing an automatic defroster function for a surface in a vehicle including a sensor for detecting the presence of mist or ice on such a surface, means for generating control signals, on the basis of the sensor data, for a number of functions in the car for an optimum defroster function on said surface, means for receiving these control signals, and means for receiving control signals from a temperature regulator in the car for a number of functions in the car. A number of the control signals from the temperature regulator are intended to control the same functions as the control signals for the optimum defroster function, and the same means are used for receiving control signals for optimum defroster function and for receiving some of the control signals from the temperature regulator. The means for receiving control signals are intended, in the event of conflict, to select those control signals that are designed to give the best defroster function.

Abstract: Methods and apparatus for freezer defrost, which are particularly suited for an automated system, include the formulation of algorithms utilized for this purpose. The algorithms are included in the firmware of an embedded controller and operate the freezer defrost cycle at temperature lows for increased efficiency. An application of the freezer defrost method and apparatus is also disclosed.

Abstract: A refrigeration system and method for controlling defrost includes a refrigeration case, an evaporator disposed in the refrigeration case, and a condenser and compressor coupled in fluid communication with the evaporator. The condenser is disposed on the refrigeration case and the compressor is a pulse width modulated variable capacity compressor. The system also includes a controller responsive to a load sensor disposed in the refrigeration case and is coupled to the compressor for providing a variable duty cycle control signal to the compressor, wherein the compressor is modulated between a first capacity and a second capacity while operating to adjust the operating capacity of the refrigeration system. The system further includes a module for periodically defrosting the refrigeration system as a function of duty cycle.

Abstract: A system and a method of automatic defrost for a refrigeration appliance, including a hermetic compressor driven by an electric motor (1); a control unit (2); a thermal switch means (10) having a first and a second turn on condition and a turn off condition and another turn off condition of the electric motor (1); a timer (20), which measures the periods of time in the turn on and turn off conditions of the electric motor (1); a switch means (40), which selectively interrupts the energization of the electric motor (1), by instruction of the control unit (2); and a cycle counting means (30), which counts each first and second turn on conditions of the electric motor (1), the control unit (2) selectively activating the thermal switch means (10) to operate in determined turn on and turn off conditions of the electric motor (1).

Abstract: Method for controlling a defrost cycle in a freezer so the defrost cycle begins at the end of a compressor operation. For the defrost cycle to begin, the compressor must have been operating for a minimum duration or the compressor must operate for a period which is a certain minimum percentage of a previous compressor operating time.

Abstract: The invention is a method and a defroster control circuit to sequentially defrost a series of refrigerated display cases. The method begins by operating the series of refrigerated display cases during a normal refrigeration mode. At the beginning of the refrigeration mode, a refrigeration time is set to zero and an elapsed refrigeration time is subsequently monitored. When the refrigeration time equals an activation time, a defrost mode begins and a defrost cycle for the first case starts. The defrost cycle for the first case terminates based either on a defrost time criterion or a defrost temperature criterion. After the first refrigerated display case is defrosted, a refrigeration cycle is restarted for the first case. After the first refrigerated display case is defrosted, the other refrigerated display cases in the series of refrigerated display cases are then sequentially defrosted.

Abstract: A method and apparatus for operating a dehumidifier in a de-ice mode is provided wherein the dehumidifier has an evaporator coil, a fan operated by a fan motor to cause a flow of ambient air over the evaporator coil, and a compressor operated by a compressor motor to cause a flow of refrigerant to the evaporator coil. A control is provided for detecting a characteristic of the dehumidifier associated with the formation of frost on the evaporator coil. Such characteristic could be the temperature of the evaporator coil, the rate of change of the temperature of the coil, a drop in the amp draw of the compressor motor below a predetermined value or a predetermined rate of downward change in the amp draw of the compressor motor. The control terminates power to the compressor motor after detection of the characteristic, either immediately or after a predetermined time, while continuing operation of the fan to provide the melting.

Abstract: The present invention relates to a method for defrosting a refrigerator with two evaporators, and more particularly, to a method for defrosting a refrigerator with two evaporators, in which the two evaporators are operated on the same time when defrosting time points of the two evaporators are close.

Abstract: Method for controlling a defrost cycle in a freezer so the defrost cycle begins at the end of a compressor operation. For the defrost cycle to begin, the compressor must have been operating for a minimum duration or the compressor must operate for a period which is a certain minimum percentage of a previous compressor operating time.

Abstract: In an automatic vending machine in which a number of items are stored in a commodity storage and cooled by a cooling unit included in a refrigerating circuit, a temperature sensor detects a storage temperature within the commodity storage to produce a temperature signal. Responsive to the temperature signal, a calculating unit calculates a temperature variation rate prior to a defrosting operation of a defrosting unit, which is intermittently carried out for the cooling unit. With reference to the temperature variation rate, a defrost control part controls the defrosting operation.

Abstract: The present invention is direct to a system and method for electronically controlling the refrigeration and/or heating of the product storage compartment in a vending machine. The system includes a temperature sensor for sensing the temperature in the product storage compartment, and a door sensor for sensing whether the door is open or closed. The control method includes the steps of activating a defrost mode, which is a timed period with no heating or cooling activity, when the door to the vending apparatus is open. The defrost mode is also activated whenever the cooling element has been running continuously for several hours. Further, the control method includes a step of cycling the cooling element “on” whenever a predetermined high temperature is reached. When the cooling element is “off” for more than 6 hours and the predetermined high temperature has not been reached, the heater is turned “on” to prevent the products in the vending machine from freezing.

Abstract: A defrost control system for a self-defrosting refrigerator is configured to monitor a compressor load, determine whether at least a first defrost cycle is required based on the compressor load, execute at least one defrost cycle when required; and regulate the defrost cycle to conserve energy. A controller is operatively coupled to a compressor, a defrost heater, and a refrigeration compartment temperature sensor. The controller makes defrost decisions based on temperature conditions in the refrigeration compartment in light of other events, such as refrigerator door openings, completed defrost cycles, and power up events. Defrost cycles are automatically adjusted as operating conditions change, thereby avoiding unnecessary energy consumption that would otherwise occur in a fixed defrost cycle.

Abstract: The present invention relates to a method for controlling a defrost heater of a refrigerator. The method for controlling a defrost heater of a refrigerator, comprising the steps of; accumulating the run time of a compressor and checking whether accumulated time has reached a predetermined time for defrosting; performing a defrost operation, if the predetermined time for defrosting is a first defrosting point of time; checking the current state of the defrost heater if the predetermined time for defrosting is not a first defrosting point of time; turning on the defrost heater to perform the on/off control of the defrost heater, if the defrost heater is turned on/off and thereafter the on/off time reaches a predetermined time; and turning off the defrost heater to finish the defrost operation, if the temperature of cooler has reached a defrost-off temperature during the on/off control of the defrost heater.

Abstract: The present invention relates to a frost and freezing (freeze-up) prevention control system for improving the efficiency of a cooling system commonly found in refrigerators, refrigerated vending machines, and or beverage coolers. Furthermore, the present invention can be retrofit onto, or originally manufactured into a cooling system. Suitable cooling systems are those commonly found in refrigerators, refrigerated vending machines and refrigerated beverage coolers. The present invention monitors, controls, and improves the efficiency of the refrigeration cycle by preventing the refrigerated cooling system from accumulating frost and or ice on critical cooling system components. Furthermore, by controlling the refrigeration cycle the present invention maintains a high level of cooling system efficiency and reduces the electrical power consumption required to operate the cooling system over the operational life of the cooling system.

Abstract: A control algorithm controls a coil defrosting cycle on a reversible heat pump by storing values representing performance of a clean coil, i.e., one with no frost build-up, and monitoring those values as they evolve over time. The values are used to create a “frost factor” whose value varies between 0%, signifying a clean coil, and 100%, signifying a heavily frosted coil. When the frost factor reaches a predetermined value close to 100%, the refrigerant cycle of the heat pump is inverted (reversed) to achieve coil defrosting.

Abstract: A de-icing system operable to facilitate the removal of ice from the door (18) and closure surface (22) of a low temperature refrigeration or ultra-low freezer device (10) and to thereby ensure proper operation of the device (10) and protect its contents. The de-icing system employs manually activated heaters (32) and a timing circuit (38) to thaw the ice. Because the de-icing system focuses heat only on specific, ice-sensitive areas, the temperature of the freezer's interior compartment (14) remains constant so that the contents need not be removed during the de-icing process. In use, an operator activates the de-icing system a few minutes prior to opening the freezer door (18). When the door (18) is opened, the melted or loosened ice can be removed with a soft cloth. If the operator forgets that the heaters have been activated, the timing circuit (38) automatically terminates the de-icing process and stops the heaters (32) before the freezer's interior storage temperature has been affected.

Abstract: In a time and temperature controlled defrost cycle for a heat pump system, defrost cycles are controlled by two variables: elapsed time since the last defrost cycle, and the refrigerant temperature in the outdoor coil. The elapsed time variable for the first defrost cycle after power-up is set less than the elapsed time variable required for subsequent defrost cycles. Thus, the system is not vulnerable to planned cyclical power outages if the power outage cycle time is less than the elapsed time variable required between regular defrost cycles.

Abstract: A cooling system and related method of defrosting a refrigeration unit or a freezer unit involves the steps of (a) monitoring a compressor running time, (b) monitoring an evaporator coil temperature, (c) monitoring a first time period since a last cooled compartment door open alarm of the unit, (d) monitoring a second time period since a last defrost operation, (e) monitoring a third time period during which the cooled compartment door is closed, and (f) controlling initiation of a defrost operation as a function of the monitored compressor running time, the monitored evaporator coil temperature, the monitored first time period, the monitored second time period, and the monitored third time period. Various sets of conditions may be established for triggering initiation of the defrost operation. The system may also detect refrigerant leaks and a clogged condenser as a function of compressor running time and compressor discharge line temperature.

Abstract: An apparatus and method for warm-liquid defrosting of the evaporator of a refrigeration system. The apparatus includes a first refrigerant expansion device that selectively expands refrigerant for cooling the evaporator, a second refrigerant expansion device that selectively expands the refrigerant after the refrigerant has passed through the evaporator, and a defrosting control for the first refrigerant expansion device and second refrigerant expansion device to selectively defrost the evaporator by causing warm refrigerant to flow through the evaporator.

Abstract: The present invention is direct to a system and method for electronically controlling the refrigeration and/or heating of the product storage compartment in a vending machine. The system includes a temperature sensor for sensing the temperature in the product storage compartment, and a door sensor for sensing whether the door is open or closed. The control method includes the steps of activating a defrost mode, which is a timed period with no heating or cooling activity, when the door to the vending apparatus is open. The defrost mode is also activated whenever the cooling element has been running continuously for several hours. Further, the control method includes a step of cycling the cooling element “on” whenever a predetermined high temperature is reached. When the cooling element is “off” for more than 6 hours and the predetermined high temperature has not been reached, the heater is turned “on” to prevent the products in the vending machine from freezing.

Abstract: A refrigerator including a freezer compartment is provided with a Stirling cycle refrigeration system including a displacer located within the freezer compartment and an external compressor which is fluidly coupled to the displacer. An electronic controller is provided to adjust a time phase relationship between the compressor and the displacer to establish a first phase condition for cooling of the freezer compartment and a second phase condition for establishing a defrost cycle for the refrigerator. The electronic controller is responsive to operator control inputs and sensor inputs. The phase relationship between the compressor and displacer is changed by substantially 180° from the first phase condition to the second phase condition.

Abstract: A refrigerated device having a cooled enclosure and an evaporator through which refrigerant is circulated. An air temperature sensor adapted to generate an air temperature signal indicative of air temperature within the enclosure is provided. A refrigerant temperature sensor adapted to generate a refrigerant temperature signal indicative of refrigerant temperature is provided. A programmable controller adapted to compare the air temperature signal and the refrigerant temperature signal to calculate a difference between the air temperature and the refrigerant temperature is provided. The controller initiates a defrost routine for removing condensate from the evaporator if the difference between the air temperature and the refrigerant temperature is greater or equal to a defrost threshold. Also disclosed are methods for defrosting a refrigerated device and for detecting condensate accumulation.

Abstract: A freezer/refrigerator vehicle equipped with a refrigerating apparatus driven by a drive source which is an engine, mounted on a vehicle, for running the vehicle, comprising an idle-up means for operating a fuel feeding device of the engine under a first idle-up condition or under a second idle-up condition between the first idle-up condition and the no-load condition, and a control means. After the defrosting cycle is conducted for a predetermined period of time while the idle-up means is in operation under the second idle-up condition, the control means operates the idle-up means under the first idle-up condition and thereafter, brings the refrigerating apparatus back to the refrigerating cycle after the passage of a predetermined period of time.

Abstract: An air conditioner system for vehicles has an exterior heat exchanger, which is used as an evaporator at the time of heating operation. A control unit monitors the heating operation and stores a defrost flag when the heating operation continues for a predetermined time period, e.g., 20 minutes, under a low exterior air temperature below a predetermined temperature, e.g., 5° C. When an electric vehicle is at rest after the heating operation to charge its secondary battery with an electric power from an external power source, the control unit first starts a defrosting operation and starts a charging operation of the secondary battery after the completion of the defrosting operation.

Abstract: The present invention relates to a frost and freezing (freeze-up) prevention control system for improving the efficiency of a cooling system commonly found in refrigerators, refrigerated vending machines, and or beverage coolers. Furthermore, the present invention can be retrofit onto, or originally manufactured into a cooling system. Suitable cooling systems are those commonly found in refrigerators, refrigerated vending machines and refrigerated beverage coolers. The present invention monitors, controls, and improves the efficiency of the refrigeration cycle by preventing the refrigerated cooling system from accumulating frost and or ice on critical cooling system components. Furthermore, by controlling the refrigeration cycle the present invention maintains a high level of cooling system efficiency and reduces the electrical power consumption required to operate the cooling system over the operational life of the cooling system.

Abstract: An improved method and apparatus for limiting the pressure in the high pressure side of a heat pump system to a safe value, without causing the defrost control circuitry thereof to initiate unnecessary defrost cycles. When the heat pump system is operating in its heating mode, pressure limiting circuitry limits the pressure in the high side thereof to a safe value by turning the outdoor fan off, and holding it off, when the vapor pressure in the vapor containing parts of the system is equal to or greater than a preset threshold pressure. When ambient conditions are such that frost is able to form on the outdoor coil, the activity of the pressure limiting circuitry is used to reset the defrost delay time or otherwise inhibit the operation of the defrost control circuitry.

Abstract: An improved defrost controller is provided for a space cooling system of the type having an evaporator in heat exchange relationship with a space to be cooled, a condenser external to the space, a compressor for circulating heat transfer fluid between the evaporator and condenser, an expansion valve located between an outlet from the condenser and an inlet to the evaporator, and a defroster operatively associated with the evaporator. The expansion valve is positionable in a plurality of positions between a fully open position and a fully closed position to maintain a desired level of superheat across the evaporator. The defrost controller monitors the expansion valve position and activates the defroster in response to the expansion valve being in a more closed position than a predetermined defrost target position.

Abstract: An operation control method for a refrigerator after a power-supply comeback due to a power-failure that performs a re-operation according to operation information stored before the power-failure.

Abstract: There is provided a refrigerator capable of suppressing intra-compartment temperature from rising during a defrosting operation by means of a defrosting heater and capable of preventing temperature of foods from rising after the defrosting operation. The inventive refrigerator sets temperature for ending a freezing mode during a pre-cooling operation at pre-cooling freezing mode ending temperature which is lower than temperature during a normal operation by a predetermined temperature and conducts an alternate cooling operation until when the pre-cooling operation ends based on the pre-cooling freezing mode ending temperature.

Abstract: A refrigerator defrost controlling method includes the step of setting an initial defrost cycle, the step of determining whether defrost entering conditions are met, the step of driving a defrost heater to remove the frost formed on the evaporator if the defrost entering conditions are met, and setting a defrost restoration temperature and a defrost cycle according to a latent heat period detected by the temperature of a defrost sensor to perform the defrost operation, the step of terminating the operation if the temperature of the defrost sensor reaches the defrost restoration temperature, and the step of resetting a defrost cycle according to the operating rate of a compressor and the number of door opening/closing times if the defrost entering conditions are not met.

Abstract: The present invention relates to an optimum defrosting cycle method of an inverter refrigerator. In the past, a defrosting cycle setting method for a conventional refrigerator with which a defrosting operation was carried out when the operation time of a compressor reaches a certain amount of time(e.g. 7 hours) by simply accumulating the operation time of the compressor. However, there have been drawbacks since the operation speed of a compressor varies for a high speed, mid speed, and low speed according to the surrounding condition when the conventional method is applied to the inverter refrigerator, it is not relevant to set the defrosting cycle by simply accumulating the operation time.

Abstract: The invention provides a method of defrosting a frost load accumulated on an evaporator, the method comprising the steps of: performing a normal mode for controlling ON-OFF operations of the compressor; sensing a temperature of the evaporator, comparing the sensed temperature with a first preset temperature to thereby determine a significant amount of frost; if the sensed temperature is less than the first preset temperature, removing the frost by activating the fan and the heater for a predetermined duration; determining whether or not the fan should be activated during the defrost mode, by sensing and comparing temperatures outside/inside the refrigerator, and a total number of instances of a refrigerator door opening and closing; checking whether or not the duration has elapsed, and if the duration has not elapsed, continuously activating the heater; and de-activating the heater if the duration has elapsed and performing the normal mode.

Abstract: A remote controlled system for remotely controlling a high load device, such as the defrosting cycle of a self-defrosting refrigerator, is provided. The system includes a data interface to receive commands from an electricity supplier and to transmit those commands via the power line to the refrigerator. The refrigerator is equipped with a power line interface to receive the commands from the power line and transmit the commands to a defrost sequencer. Between the power line interface and the defrost sequencer may be provided another interface that converts the commands into a digital signal more suitable for the defrost sequencer, which is typically a microprocessor.

Abstract: A defrosting apparatus of an air conditioner and method thereof are provided to efficiently carry out a defrosting operation during the heating operation by comparing temperature of an outdoor heat-exchanger, an outdoor temperature and an operation time of a compressor to correctly discriminate whether the frost has accumulated at an outdoor unit, to thereby effectively carry out defrosting operation, the air conditioner having an outdoor heat-exchanger to heat-exchange the outdoor air and a compressor to compress a coolant for being heat-exchanged at the heat-exchanger, the apparatus comprising: a pipe temperature detecting unit to detect the outdoor temperature; an outdoor temperature detecting unit to detect the outdoor temperature during the heating operation via the operation of the compressor; a controlling unit to control the defrosting operation by discriminating the accumulation of the frost on the outdoor unit with consideration of the temperature of the outdoor heat-exchanger, the outdoor temperatu

Abstract: A defrost control for a heat exchange system initiates a defrost of the evaporator coil when a predetermined count of compressor cycles occurs and other sensed conditions indicate that defrost should be initiated. The sensed conditions include a sensed temperature of a condenser coil in the heat exchange system having dropped below a threshold temperature computed as a function of the number of compressor cycles that have occurred since the last defrost of the evaporator coil.

Abstract: The invention comprises a merchandiser having a refrigerated product area with a plurality of product zones and separate air flow circulation means for the respective product zones, laterally adjacent modular cooling coils associated with the respective air flow circulation means and having a normal air flow cooling mode, and defrosting means constructed and arranged for selectively discontinuing the normal cooling mode of one modular cooling coil to effect a defrosting mode thereof during a period of continued normal cooling mode operation of another of said modular cooling coils, and thereafter defrosting another modular cooling means after re-establishing normal air flow cooling of said one modular cooling coil. The invention further comprises the method of defrosting separate modular cooling coils on staggered defrost cycles to maintain at least partial cooling air flow to the merchandiser product area at all times.

Abstract: A fluid defrost system and method for defrosting the cooling coil of a product fixture normally cooled by circulating a cold secondary liquid coolant in a cooling loop refrigerated by a primary vapor compression system having compressor, condenser and evaporator means; the defrost system comprising a heat exchanger associated with the condenser means for warming secondary liquid coolant in a heating loop, and means for controlling the circulation of warm liquid coolant through the heat exchanger and cooling coil.

Abstract: A defrost control method and apparatus for a refrigerator having a defrosting heater for defrosting the evaporator. The method classifies a plurality of operating condition cases based on outside temperature of the cabinet and door opening number. Each of the operating condition cases has a predetermined severity factor. It is obtained a frosting weight for the unit time interval by multiplying a compressor operating time with the severity factor of the operating condition case. The frosting weights for a plurality of the unit time interval are accumulated and a defrosting operation is performed when the accumulated frosting weight exceeds a predetermined value.

Abstract: Disclosed is a controlling method for minimizing a temperature deviation in a refrigerator by optimally varying a pausing period of a defrosting operation based on a present temperature in the refrigerator and the pressure of the discharging outlet of a compressor. A controlling section removes frost formed at the evaporation of a freezing compartment during the common operation of the refrigerator and stops the operation of a heater for the defrosting operation. In order to stabilize the temperature in the refrigerator, the controlling section compares the temperature in the refrigerator with the operating temperature of the compressor during the pausing period. When the temperature in the refrigerator is not less than the operating temperature of the compressor, the controlling section compares the pressure of the discharging outlet of the compressor with the operating pressure of the compressor.

Abstract: A refrigeration controller is provided which thermostatically controls a refrigerated compartment temperature. A heated evaporator is provided within a certain wattage range to accelerate defrosting. The controller maintains the compartment temperature within a certain operating range; if the compartment temperature rises above a certain preselected maximum temperature, the controller activates the compressor and a blower to circulate air over the evaporator to reduce the temperature of the compartment. The controller provides a defrost loop which is periodically activated which controls the compressor, evaporator and heater cycle during defrost. If, during defrost, the evaporator reaches a maximum temperature, or if the food compartment temperature rises above a certain maximum, the heater is deactivated. An evaporator precool loop is provided which activates the compressor without activating the blower, thereby cooling the evaporator before hot air is allowed to circulate in the compartment.

Abstract: A defrosting apparatus for a refrigerator and a method for controlling the defrosting apparatus, wherein the refrigerating compartment is cooled irrespective of the internal temperature of the freezing compartment when the internal temperature of the refrigerating compartment is higher than a predetermined temperature, so that the refrigerating compartment is maintained below the predetermined temperature. The defrosting operation is carried out in accordance with the drive times of the compressor and refrigerating compartment fan when the internal temperature of the refrigerating compartment is higher than the predetermined temperature even though the compressor and refrigerating compartment fan are continuously driven. Accordingly, it is possible to improve the cooling efficiency.

Abstract: A method for defrosting a refrigeration system makes provision for partial defrosting of the cooling surface to be carried out at relatively short intervals, and for full defrosting to be carried out at longer intervals. To that end an associated control unit has four timers which determine the switching on and switching off times of the defrosting processes. In this manner the interval between successive full defrostings can be considerably increased.