Abstract: A process for controlling an air conditioner/heater by thermal storage comprises the steps of sending ambient temperature of at least one enclosed space sensed by a plurality of sensors to CPU for comparison with a predetermined value; switching to operate in one of air conditioning, heating, and hot water supplying modes; and if switching to the air conditioning mode and the temperature of thermal storage is less than or equal to the predetermined value, a compressor is turned off, an outdoor fan motor is turned off, and a solenoid-controlled valve is turned on to cause the process to enter into a melting cycle. With this automatic switching, the operation is maintained at an optimum, resulting in an increase of thermal efficiency.

Abstract: A heat pump system having an operable relationship for transferring heat between an exterior atmosphere and an interior atmosphere via a fluid refrigerant and further having a compressor, an interior heat exchanger, an exterior heat exchanger, a heat pump reversing valve, an accumulator, a thermal expansion valve having a remote sensing bulb disposed in heat transferable contact with the refrigerant piping section between said accumulator and said reversing valve, an outdoor temperature sensor, and a first means for heating said remote sensing bulb in response to said outdoor temperature sensor thereby opening said thermal expansion valve to raise suction pressure in order to mitigate defrosting of said exterior heat exchanger wherein said heat pump continues to operate in a heating mode.

Abstract: A defrost control system detects the variation in flow rate of refrigerant through an evaporator 8 while the flow is regulated to achieve a desired level of superheat at the outlet of the evaporator 8. When the flow rate becomes unstable, defrosting of the evaporator 8 is triggered.

Abstract: Adaptive defrost control and method for a household refrigerator wherein a defrost interval is adjusted based upon the time it takes for a previous defrost cycle to complete. The adaptive defrost control also provides a vacation mode in which the defrost interval is set to an artificially long interval if a door of refrigerator has not been opened for some predetermined period of time. Further a defrost termination thermostat is provided that is stable during power interruption. The termination thermostat is used as a memory device to determine whether a defrost cycle was in process when power was interrupted.

Abstract: A method of and apparatus for controlling a refrigeration plant having a cooler for cooling cooling air, the surface temperature of the cooler being measured by a single sensor and the cooling-air temperature being derived from the surface temperature of the cooler via a correction factor, the refrigeration plant then being controlled an the basis of the measured temperature value and the derived temperature value.

Abstract: A high-speed evaporator defrost system is described. It comprises a defrost conduit circuit having valves for directing hot high pressure refrigerant gas from a discharge line of a compressor and through a refrigeration coil of an evaporator of a refrigeration system during a defrost cycle thereof, and back to a suction header of the compressor through a reservoir of the refrigeration system to remove any liquid refrigerant contained in the refrigerant gas prior to returning to the suction header. The reservoir has an internal pressure which is generally at the same pressure as that of a suction header of the compressor thereby creating a pressure differential across the refrigeration coil sufficient to accelerate the hot high pressure refrigerant gas in the discharge line through the refrigeration coil of the evaporator to quickly defrost the refrigeration coil. The reservoir is repressurized after the defrost cycle for using the reservoir in a refrigeration cycle.

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: A heat pump type hot-water supply system performs an ordinary operation for heating liquid stored in a reservoir by circulating the liquid in a heat exchanger for supplying hot water. When an outlet temperature of an exterior heat exchanger is lowered to about −5° C., the ordinary operation is switched to a defrosting operation, and an opening degree of an expansion valve is decreases as compared to that at the ordinary operation. Accordingly, hot gas discharged from a compressor radiates a decreased amount of thermal energy in the heat exchanger for supplying the hot gas. Hot gas discharged from the compressor can reach the exterior heat exchanger without lowering its temperature largely to perform defrosting of the exterior heat exchanger.

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: An air conditioner/heater automatically operates in either air conditioning or heating mode by coil temperatures of indoor and outdoor heat exchangers. In air conditioning mode, the rotating speed of indoor fan motor is proportional to the ambient temperature of corresponding enclosed space, and the rotating speed of outdoor fan motor is proportional to the coil temperature of corresponding outdoor heat exchanger. In heating mode, the rotating speed of indoor fan motor is proportional to the coil temperature of corresponding indoor heat exchanger, and the rotating speed of outdoor fan motor is inversely proportional to the coil temperature of corresponding outdoor heat exchanger. With this automatic switching of operation mode, the capability of heat dissipation of condenser is always larger than the capability of heat absorption of evaporator. Hence, the operation of the air conditioner/heater is maintained at an optimum.

Abstract: Heating/defrost constructions of a very loW temperature refrigeration system having a defrost supply circuit and a defrost return bypass circuit optimizing the heating/defrost cycle, preventing overload (excessive pressure) of its refrigeration process and protecting components from damaging temperatures. The defrost cycle operates continuously, when required, and provides a shorter recovery period between heating/defrost and cooling operating modes. The rate of the temperature change during cool down or warm up is controlled in an open loop fashion by controlled refrigerant flow in bypass circuits.

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: An operation control apparatus for a refrigerator performs a cooling operation by using a refrigerating compartment temperature regulator directly connected to a power-supply input terminal even if a freezing compartment temperature regulator is turned off, thereby effectively restricting an increase of the inside temperature of the refrigerating compartment.

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 controller monitors the saturated suction temperature and the saturated discharge temperature of a system that includes a compressor operating as part of a chiller and/or heat pump. When the compressor operates outside its compressor map, the controller takes action to ensure the compressor operates only within its compressor map. Such actions include defrosting the compressor coil if the system is in heating mode or unloading the unit.

Abstract: A control processor controls an outdoor coil defrost cycle on a reversible heat pump by continuously monitoring the difference between the outdoor coil temperature and the outdoor air temperature. When specified preconditions are met and this difference exceeds a target value, the defrost cycle is initiated.

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: 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: 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: A control system for mobile air conditioning systems for controlling the rate at which the system compressor or clutch is cycled between operational and decreased refrigerant flow, by selectively controlling the response time of certain system control signals to flow demand changes including de-icing control, from interactions between de-icing control and flow control valves, as well as system overall control. Upon the detection of an icing condition, the response of the control system is delayed to a degree to control the rate at which the capacity of the compressor can be cycled with in design limits. The delay feature allows the differential used in differentiating between icing and non-icing conditions to be significantly reduced over that required in the prior art and thereby improving the performance of the air conditioning 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 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: An Improved Refrigeration System and Heating/Defrost Cycle is disclosed. The system, for heating circulating air and defrosting an enclosed area, includes a refrigerant, an evaporator using said refrigerant for heating the circulating air; and a compressor for receiving the refrigerant from the evaporator and compressing the refrigerant to a higher temperature and pressure. Advantageously, the system further includes the combination of an expansion valve positioned between the compressor and the evaporator for forming a partially expanded refrigerant, a controller for sensing system parameters, and a mechanism responsive to said controller, based on the sensed parameters, for increasing temperature differential between the refrigerant and the circulating air, for improving system efficiency and for optimizing system capacity during heating and defrost cycles.

Abstract: A frost deposition detecting device is provided. This frost deposition detecting device comprises: a base member 1; a heat-conductive container 4 including a frosting portion provided to the base member 1; a thermally sensitive element 6' for detecting the temperature of the base member 1; a protection pipe 8 inserted into the base member 1 and disposed in the cavity formed inside the heat-conductive container; a heat insulator integrally formed with the protection pipe 8 to reduce heat conduction to the protection pipe 8; and another thermally sensitive element 6 secured in the protection pipe 8. With such frost deposition detecting device, highly accurate frost detecting performance and excellent durability in terms of water resistance and humidity resistance can be achieved.

Abstract: A high-speed evaporator defrost system is comprised of a defrost conduit circuit connected to the discharge line of one or more compressors and back to the suction header through an auxiliary reservoir capable of storing the entire refrigerant load of the refrigeration system. Auxiliary reservoir is at low pressure and is automatically flushed into the main reservoir when liquid refrigerant accumulates to a predetermined level. The auxiliary reservoir of the defrost circuit creates a pressure differential across the refrigeration coil of the evaporators sufficient to accelerate the hot high pressure refrigerant gas in the discharge line through the refrigeration coil of the evaporator to quickly defrost the refrigeration coil even at low compressor head pressures and wherein the pressure differential across the coil is in the range of from about 30 p.s.i. to 200 p.s.i.

Abstract: A heating system control unit is provided for use with a heating system. The control unit includes a switching element connected to a first temperature switch associated with a first stage heater, a second temperature switch and a second stage heater of the heating system. The switching element is adapted for actuating the second stage heater upon the receipt of the second temperature signal and further continuing the actuation of the second stage heater until the lack of receipt of both the first temperature signal and the second temperature signal. A thermostat on the outdoor coil serves to pass the signal from the second temperature switch only upon a temperature of the outdoor coil being below a predetermined amount of about 25 degrees Fahrenheit.

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 reference temperature of the cooler is set which is required to moderate an interior temperature of the refrigerator. During a defrosting mode, if a door is opened, then a control part switches on an air curtain fan if a temperature of a cooler is lower than the reference temperature, or switches it off if it is not lower. The control part switches off the air curtain fan when the door is closed. Meanwhile, during the defrosting mode, if the door is closed, then the control part switches on the air curtain fan if the temperature of the cooler is lower than the reference temperature in a heating state, or switches it off if it is not lower. The air curtain fan is also switched off if it is not in a heating state. Thus, the air curtain fan is driven depending on interior and exterior conditions during a defrosting operation of the refrigerator. Thereby, refrigerating efficiency as well as defrosting efficiency are increased.

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: A method for preventing an evaporator of an air conditioner from freezing comprises the steps of (1) detecting an outdoor temperature, (2) determining whether or not the outdoor temperature is 20.degree. C., (3) determining whether or not the outdoor temperature is in a first temperature range, (4) determining whether or not the outdoor temperature is in a second temperature range, (5) varying an R.P.M. of the motor assembly based on the outdoor temperature detected in steps (3) and (4), (6) detecting a surface temperature of a condenser and determining whether or not the surface temperature of the condenser is in a third temperature range, (7) repeating steps (1) through (6) if the surface temperature of the condenser is higher than the third temperature range, and (8) rotating the motor assembly at a low speed if the surface temperature of the condensor is lower than the third temperature range.

Abstract: A frost detecting device including a frost detector which detects the amount of frost from the temperature difference between a detecting thermal sensitive element and a compensating thermal sensitive element is provided. The frost detecting device includes: a frost detector 1 made up of a detecting thermal sensitive element and a compensating thermal sensitive element; an amplifier circuit 2 for amplifying an output signal from the frost detector 1; a comparator circuit 3 for comparing an output voltage from the amplifier circuit 2 with a set level; an operation detecting circuit 5 for detecting operating conditions of a compressor and a cooling fan 4; and a judging circuit 6 for detecting the amount of frost in accordance with output voltages from the operation detecting circuit 5 and the comparator circuit 3. The output from the comparator circuit 3 is used to detect the amount of frost only when the compressor and the cooling fan 4 are both in operation.

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 reverse cycle refrigeration apparatus for air dehumidification is employed having an evaporator and a condenser and employing first and a second heat transfer coils for this purpose. Both coils are positioned in the air stream. In a first cycle the second coil functions as the evaporator for cooling and dehumidifying the air stream and accumulating frost and the first coil acts as the condenser, warming the cooled and dehumidified air stream and thawing frost having accumulated on it. In a second cycle the first coil acts as the evaporator, cooling and dehumidifying the air and providing the heat for defrost and the second coil acts as the condenser, thereby being defrosted. Dampers are provided for stopping air flow over the defrosting coil.

Abstract: In a heat pump type air conditioner, a refrigerant ejection port of a compressor in a refrigerating cycle thereof is connected to a refrigerant inflow port of an outdoor heat exchanger via a bypass pipe with a shut-off valve, and temperature sensors detect the temperatures of the refrigerant inflow and runoff port sides of an outdoor heat exchanger. In a heating operation mode, when the temperature of the refrigerant inflow or runoff port side reaches a certain value or lower that requires defrosting, the shut-off valve of the bypass pipe is "opened" to start defrosting using the hot gas bypass defrosting method.

Abstract: A control circuit for a refrigeration system disposed within an outer cabinet having a freezer compartment, a fresh food compartment, a compressor, a condenser fan, an evaporator fan, an evaporator and a freezer thermostat disposed within the freezer compartment to sense temperature therein. Additionally, a fresh food thermostat is disposed within the fresh food compartment to sense temperature therein. A freezer thermostat switch is switched between an open state and a closed state in response to temperature signals generated from the freezer thermostat. A fresh food thermostat switch is switched between an open state and a closed state in response to temperature signals generated from the fresh food thermostat. An energy saver switch is disposed between the fresh food thermostat switch and a power source, which energy saver switch is switched between an open state and a closed state.

Abstract: A process and an arrangement for controlling an air conditioner utilize an evaporator protected against icing and a refrigerant circulating system which includes at least one compressor and the evaporator. The evaporator temperature is sensed continuously and the compressor is deactivated when the evaporator temperature falls below a defined switch-off temperature. The compressor is activated again when the evaporator temperature exceeds a defined switch-on temperature which is at least equal to the switch-off temperature. The evaporator temperature gradient is determined by a corresponding control unit from the continuous sensing of the evaporator temperature.

Abstract: The evaporator and the condenser are disposed in a duct. First bypass passage is disposed at the side of the condenser and first air mixing damper rotates to control air bypassing amount. Further second bypass passage is formed at the side of the evaporator and second mixing damper rotates to control air bypassing amount. Cooling rate at the evaporator and heating rate at the condenser are varied so that air adjusted in proper temperature is generated and discharged from each outlets into a room. An outside heat exchanger is disposed the outside of the duct. Refrigerant flow is randomly switched among the outside heat exchanger, the evaporator and the condenser so that cooling, heating, dehumidifying, dehumidified-heating and defrosting operations are performed.

Abstract: A refrigerating cycle apparatus including an inverter driven compressor with controllable speed of rotation, a four-way valve, an indoor heat exchanger, a pressure reducing device, outdoor heat exchanger, a defrosting condition detector for detecting a frosting state of the outdoor heat exchanger in a heating operation, a defrosting operation controller for carrying out a defrosting operation based on a detection signal from the defrosting condition detector and having a minimum operable frequency controller for controlling a minimum operable frequency for the compressor on restarting after completion of the defrosting operation and/or a starting speed controller for controlling a starting speed for the compressor based on a detection signal from the defrosting condition detector on restarting after completion of the defrosting operation in order to provide proper lubrication after a defrost operation.

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: A refrigerator includes a defrosting heater. An outdoor air temperature sensor senses a temperature of outside air. A defrosting time period of the heater is set as a function of the outside air temperature. If it is determined that the temperature sensor is inoperative, i.e., if the sensor indicates that the outside air temperature is above 50.degree. C. or below -50.degree. C., the defrosting period which is set is the same, regardless of whether the sensor indicates the outside air temperature to be above 50.degree. C. or below -50.degree. C.

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: This invention provides an air conditioner for simultaneously cooling or heating a plurality of rooms by using a single outdoor unit and at least two and more indoor units connected to the outdoor unit, the air conditioner including indoor heat exchangers installed in each room, for heat-exchanging a room air, a unit for detecting varying temperatures of conduit during the air conditioning, a control unit for controlling low temperature, high temperature, and defrosting operations for respective indoor units on the basis of the detected conduit temperature, and for coding operation states of respective indoors to input/output the coded communication signals, a communicating unit for transmitting and receiving the coded communication signals through input/output ports provided with the control unit for communicating between any indoor units.

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: An ice making machine comprises a refrigerant system having a compressor, a condenser, an expansion device, an evaporator and interconnecting refrigerant lines; a water system having a fresh water inlet, a water circulation mechanism, an ice-forming device in thermal contact with the evaporator and interconnecting water lines; and a control system comprising a temperature sensing device in thermal contact with the outlet of the condenser, and a microprocessor programmed to use input from the temperature sensing device either i) at a predetermined time after initiation of a freeze cycle to determine the desired duration of the freeze cycle or ii) at a predetermined time prior to the end of the freeze cycle to determine the desired duration of the harvest cycle, or iii) both i) and ii), to control the refrigeration and water systems to operate in a freeze cycle and/or the harvest cycle until the end of the desired duration(s).

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 heat pump system includes, in an operable relationship for transferring heat between an exterior atmosphere and an interior atmosphere via a fluid refrigerant: a compressor; an interior heat exchanger; an exterior heat exchanger; an accumulator; and means for heating the accumulator in order to defrost the exterior heat exchanger.

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 defrost control system comprises a superheat detector for detecting the degree of superheat of refrigerant leaving an evaporator or the presence of liquid in the refrigerant, a temperature sensor for sensing the temperature of a thermal load cooled by the evaporator and an electrically operable expansion valve for controlling the flow of refrigerant through the evaporator, each connected to a control circuit. In normal operation, the control circuit controls the flow of refrigerant to keep the temperature of the thermal load constant. However, if the superheat detector detects that the superheat is too low, the control circuit overrides the normal operation and reduces the flow of refrigerant. If the control circuit determines that the time spent in override condition over a period exceeds a maximum level, defrosting of the evaporator is triggered.