Abstract: Provided is an air-conditioning apparatus including a plurality of indoor units for an outdoor unit, which is capable of determining whether there is occurrence of frost formation on the outdoor unit during a heating operation so as to enable a transition to a defrosting operation at an appropriate timing. Each of the indoor units is configured to transmit an operating-state notification for notifying a self-operating state to the outdoor unit. The outdoor unit is configured to determine the number of indoor units performing the heating operation among the plurality of indoor units based on the operating-state notifications, and determine the occurrence of the frost formation after elapse of a preset time period from a time at which the number of the indoor units performing the heating operation changes.

Abstract: Air flow designs for controlling the temperature in a temperature controlled compartment in a refrigerator are disclosed. One configuration includes a refrigerator with a cabinet having a freezer compartment and refrigerator compartment. The refrigerator may be configured with a first air return pathway between the refrigerator compartment and the freezer compartment for returning relatively warm air from the refrigerator compartment to the freezer compartment and a second air return pathway between the refrigerator compartment and the freezer compartment. A fan may be associated with the first or second air return pathway, that when activated the first or second air return pathway acts as an air supply pathway to supply cold air from the freezer compartment to the refrigerator compartment.

Abstract: A method of operating a heat pump system is provided, the heat pump system having at least a controller and configured to operate at least two defrost cycles. The method comprises receiving, at the controller, weather data for a defined geographic area proximate to an installed location of the heat pump system; and selecting, based on said weather data, one of the at least two defrost cycles.

Abstract: An air conditioner for a vehicle includes: a compressor that compresses a heat exchange medium; an internal heat exchanger that performs heat exchange between the heat exchange medium expelled from the compressor and air for air conditioning introduced inside a vehicle compartment; and an external heat exchanger that performs heat exchange between the heat exchange medium expelled from the internal heat exchanger and external air, wherein the air conditioner for a vehicle calculates a temperature difference between an external air temperature and a discharge port temperature of the external heat exchanger, calculates an average value of the temperature difference, and performs a defrosting operation which melts frost adhered to the external heat exchanger when an amount of change of the average value is equal to or greater than a first predetermined value.

Abstract: An outdoor unit includes a bypass circuit that makes a part of refrigerant that is discharged from a compressor be bypassed to a connecting part at the time of defrosting operation. A control device of the outdoor unit performs control of opening an electromagnetic valve in the bypass circuit based on an water temperature TW (in) in an water inlet and an water temperature TW (out) in an water outlet of an water heat exchanger at the time of the defrosting operation. Further, a control device controls a valve travel of the valve of the third expansion valve in the bypass circuit based on a refrigerant temperature TR (in) in a refrigerant inlet and a refrigerant temperature TR (out) in a refrigerant outlet of the water heat exchanger in a case of the electromagnetic valve being in an open state at the time of the defrosting operation.

Abstract: A thermal management system for an electric vehicle that is used in the electric vehicle driven by an electric motor includes a refrigerant loop for an air conditioner, a refrigerant loop for a battery that allows a refrigerant for the battery to circulate among the battery, an evaporating unit and a heating device, and thermal management controlling means that, during charging of the battery, heats the refrigerant for the battery by using the heating device when temperature of the refrigerant for the battery is lower than target temperature of the refrigerant for the battery, and that allows the refrigerant for the air conditioner to circulate and to absorb heat from the refrigerant for the battery, in the evaporating unit, when the temperature of the refrigerant for the battery is higher than the target temperature of the refrigerant for the battery.

Abstract: When a temperature of feed air blown into a space for air conditioning cannot be increased up to the target temperature in an indoor condenser of a heat pump cycle included in a gas injection cycle, the volume of the feed air flowing into the indoor condenser is decreased. Thus, the temperature of the refrigerant condensed by the indoor condenser is increased, while the amount of a compression work in a high-pressure side compression stage of the compressor is increased, which suppresses the lack of the heating capacity of the feed air blown into the space for air conditioning.

Abstract: An air conditioning system, including a condenser for condensing a refrigerant, a first expansion device for throttling the refrigerant passed through the condenser, a second expansion device for throttling the refrigerant passed through the first expansion device, an evaporator for evaporating the refrigerant passed through the second expansion device, a compressor for compressing the refrigerant passed through the evaporator and the refrigerant injected after branched between the first expansion device and the second expansion device, and a control unit for detecting a value of at least one operating parameter and determining a target opening degree of the first expansion device on the basis of a stored set value corresponding to the detected value of the operating parameter.

Abstract: A first flow switching device causes part of a refrigerant discharged from an injection compressor to flow through a first bypass pipe and be supplied to an outdoor heat exchanger targeting for defrosting. A second flow switching device causes part of the refrigerant supplied to the outdoor heat exchanger targeting for defrosting to enter a second bypass pipe.

Abstract: A drying system and a laundry drying device are provided. The drying system includes a compressor, a draught fan, a casing, a throttling device, an evaporator and a condenser. The condenser and the evaporator are relatively fixedly arranged inside the casing, and the evaporator is obliquely arranged inside the casing; an inner space of the casing at least includes a first space at one side of the evaporator, a second space between the evaporator and the condenser, and a third space at another side of the condenser; a bottom portion of the casing is provided with a water reserving portion or a drainage hole, and the casing has a high point A at a portion where the condenser is arranged and a high point B at a portion where the evaporator is arranged, and the high point A is substantially same as the high point B.

Abstract: Method and device for defrosting of an evaporator (1) in a heat pump (2) connected to an air handling unit (9), which comprises a controllable heat recovery device (10). The heat pump (2) comprises a refrigerant system (3) with a refrigerant (4), a compressor (5), a condenser (6), a first expansion valve (7) and an evaporator (1). A four-way valve (8) is arranged after the compressor (5) and before the condenser (6), for changing a flow direction of the refrigerant (4) to the evaporator (1) instead of the condenser (6). The heat recovery device (10) recovers energy from first air stream (11) and transfer energy to second air stream (12). When frost formation occurs, the refrigerant temperature is increased and the recovery device (10) is regulated down so that heating of the evaporator (1) is accomplished, both from inside and outside to defrost the evaporator (1).

Abstract: A high performance refrigerator or freezer includes a cabinet with a refrigerated interior, a first evaporator cover separating a first evaporator compartment within the cabinet from the refrigerated interior, and a refrigeration fluid circuit having a first evaporator located within the first evaporator compartment, a second evaporator, and a three-way valve enabling selective communication of refrigerant to one or both of the evaporators. The second evaporator includes an air diffuser that receives chilled air from the first evaporator compartment and delivers the chilled air into the refrigerated interior. During normal operation, the three-way valve only directs refrigerant into the first evaporator such that the first evaporator cools the cabinet and the chilled air from the first evaporator passively defrosts the second evaporator by sublimation.

Abstract: Disclosed is a monitoring and control system for an air source heat pump apparatus having a controller to control at least one operation of the heat pump apparatus, a temperature sensor to detect the temperature in a specified area at, near, and/or around the controller, and an operable component, the system including a control program to: determine the temperature based on the detected temperature of the temperature sensor; determine whether a first condition exists, the first condition including a determination that the controller is powered, but the operable component is not operating; determine whether a second condition exists, the second condition including a determination that the controller is powered, and the operable component is operating; and based at least partially on determinations (a)-(c), determine the ambient temperature at or around the heat pump apparatus.

Abstract: A method for controlling a heat pump system is provided with air conditioning means connected to a controller and including a plurality of valves and expansion valves connected to each other through a refrigerant line and a bypass line, a compressor, an accumulator, an evaporator, an exterior condenser, an interior condenser, and an HVAC module having a PTC heater and a door at a warming mode, a cooling mode, a dehumidification mode, a dehumidification/defrosting mode, or an extremely low temperature dehumidification/defrosting mode according to selection of a driver.

Abstract: A conversion unit for an air conditioning system to cause it to act like the cooling unit of a refrigeration system comprises a frost detector, an A/C temperature control defeating mechanism and a control unit which operate together to force the range of operation of the air conditioning unit into the range of operation of a refrigeration unit. The conversion unit is particularly useful for providing low cost cooling systems for farmers in third world countries for keeping their produce fresh and safe, not to mention its use by all farmers around the world and by florists or others in need or desire of an economical refrigeration alternative. The present invention is also usable to provide inexpensive cooling to RV's and to refrigerated vehicles.

Abstract: In various implementations, defrost operations may be managed. A change in the temperature of a heat exchanger may be determined. A determination whether to allow a defrost operation may be at least partially based on the determined change in the temperature of the heat exchanger.

Abstract: A system and method for controlling automatic defrost of a refrigerator device adaptively moves the defrost cycle to a time period of comparatively low compressor activity based on an evaluation of compressor usage over a cyclically recurring time interval. An adaptive defrost controller (ADC) analyzes stored data to develop a profile for compressor activity vs. time. From this profile, high compressor activity times of the time interval are distinguished from low compressor activity times in the time interval and a defrost cycle is scheduled based on the results of the analyzed data.

Abstract: A system and method of heat exchanger freeze protection for an HVAC system by operating an indoor unit assembly and an outdoor unit assembly in a cooling mode and operating a fan at an initial airflow, operating a temperature sensor to measure a temperature value of a heat exchanger, at the expiration of a first predetermined time period, determining whether the temperature value is less than or equal to a first temperature preset value, determining whether a current airflow multiplier is equal to a maximum airflow multiplier limit, increasing the current airflow by an airflow offset multiplier if the current airflow multiplier is less than or equal to the maximum airflow multiplier limit and the temperature value is less than or equal to the first temperature preset, and operating the fan at an increased airflow to move more air across the heat exchanger.

Abstract: Temperature sensors detect an outdoor air temperature and a heat exchanger temperature of an outdoor unit, and a human detection sensor detects presence of a person in an air blowable region of each indoor unit. A control section selectively executes a first defrosting operation mode in which a defrosting operation is performed while fans of all the indoor units are stopped, and a second defrosting operation mode in which, when a frost formation amount in the heat exchanger is estimated to exceed a threshold value on the basis of the temperatures detected by the first and second temperature sensors, the indoor unit for which the human detection sensor detects no person in its air blowable region is preferentially selected, and a defrosting operation is performed while the fan of the indoor unit is forcibly operated. Such an air conditioning system and a defrosting operation method reduce time required for defrosting.

Abstract: The present invention relates to a supercooling system and a method for displaying a supercooled state which can accurately display a supercooled state of a stored object in spite of the external influence.

Abstract: A system and methods providing real-time monitoring, management and control of a variable frequency drive retrofit to a constant volume air handling unit without making significant mechanical or control system changes. Customers and vendors are provided with a more informative and economically attractive air handling unit. The system also provides a finer granularity of control over conditioned air properties such as temperature, humidity and air quality.

Abstract: The air conditioner 1 includes an outdoor unit 10 and an indoor unit 30. The outdoor unit 10 includes an outdoor heat exchanger 16, a compressor 12, an outdoor fan 15, a temperature detector 23 for detecting a temperature of the outdoor heat exchanger 16, and a temperature detector 27 for detecting an outdoor temperature. The indoor unit 30 includes an indoor heat exchanger 33 and an indoor fan 32. The air conditioner 1 has a heating operation mode: that is, when the outdoor temperature reaches a predetermined first specified temperature or lower during a heating operation, the air conditioner 1 stops the heating operation and goes to standby, and thereafter, when the outdoor temperature reaches a temperature equal to or higher than a predetermined second specified temperature higher than the first specified temperature, the air conditioner 1 executes a defrosting operation and subsequently resumes the heating operation.

Abstract: An outdoor unit of an air conditioner includes: an outdoor fan; an outdoor air temperature detector; and a controller, wherein the controller performs: a fan defrost operation to circulate the refrigerant in the same order as in the case of a cooling operation and rotate the outdoor fan when the outdoor air temperature is within a predetermined temperature range, a fan defrost operation over a period of a first fan defrost operation time when the outdoor air temperature is lower than a first predetermined temperature, and a fan defrost operation over a period of a second fan defrost operation time that is longer than the first fan defrost operation time when the outdoor air temperature is equal to or higher than a second predetermined temperature that is higher than the first predetermined temperature.

Abstract: An automobile which includes a radiator fan control for heat pump HVAC which can selectively reverse fan direction based on ambient temperature and moisture to reduce ice buildup on a liquid-gas converter. The automobile may include a liquid-gas converter located within an engine bay, a radiator located adjacent the liquid-gas converter, a first fan located adjacent the radiator, a fuel cell and motor with the inverter located adjacent the first fan, the fuel cell supplying electricity to the motor with the inverter to drive the vehicle. The automobile can also include a temperature sensor located on an exterior surface of the automobile to sense an ambient temperature, a heater core connected to the liquid-gas converter and located between the engine bay and the passenger area, and a control unit connected to the first fan, the temperature sensor, and the heater core.

Abstract: An automobile which includes a radiator fan control for heat pump HVAC which can selectively reverse fan direction based on ambient temperature and moisture to reduce ice buildup on a liquid-gas converter. The automobile may include a liquid-gas converter located within an engine bay, a radiator located adjacent the liquid-gas converter, a first fan located adjacent the radiator, a fuel cell and motor with the inverter located adjacent the first fan, the fuel cell supplying electricity to the motor with the inverter to drive the vehicle. The automobile can also include a temperature sensor located on an exterior surface of the automobile to sense an ambient temperature, a heater core connected to the liquid-gas converter and located between the engine bay and the passenger area, and a control unit connected to the first fan, the temperature sensor, and the heater core.

Abstract: Apparatus and method are provided for facilitating cooling of an electronic component of varying heat load. The apparatus includes a refrigerant evaporator coupled in thermal communication with the electronic component, a refrigerant loop coupled in fluid communication with the refrigerant evaporator for facilitating flow of refrigerant through the evaporator, and a thermoelectric array disposed in thermal communication with the evaporator. The thermoelectric array includes one or more thermoelectric elements, and is powered by a voltage and by a current of switchable polarity, which are controlled to maintain heat load on refrigerant flowing through the refrigerant evaporator within a steady state range, notwithstanding varying of the heat load applied to the refrigerant flowing through the refrigerant by the at least one electronic component.

Abstract: A refrigerant circuit of a heat pump water heater has a compressor, a four-way valve, a water heat exchanger, a heat storage transfer pipe contained in a heat storage water tank, an expansion valve, and an air heat exchanger and forms a refrigerating cycle by sequentially connecting them. A water circuit of the heat pump water heater has a water inlet pipeline that supplies water to the water heat exchanger, a hot water tank, and a water outlet pipeline that allows the water heat exchanger to communicate with the hot water tank, in which water is supplied to the heat storage water tank through a heat storage water tank water feed pipe branching from the water inlet pipeline by opening a heat storage water tank water feed opening/closing valve) and the water in the heat storage water tank can be discharged through the heat storage water tank water discharge pipe (by opening a heat storage water tank water discharge opening/closing valve).

Abstract: In an air-conditioning apparatus, a heat source side heat exchanger, intermediate heat exchangers, and use side heat exchangers are separately formed and adapted to be disposed at separate locations, respectively. There is provided a defrosting operation function to melt frost attached around the heat source side heat exchanger, and a heating function during defrosting operation that drives a pump to circulate a heat medium and supply heating energy to the use side heat exchangers in need of heating to perform heating operation. The defrosting operation function can be executed by switching a four-way valve to cooling side to introduce a high-temperature high-pressure refrigerant flowed out of the compressor into the heat source side heat exchanger.

Abstract: A heat pump apparatus includes a refrigerant circuit in which a compressor, a condenser, expansion means, and an evaporator are serially connected. Condensation temperature detection means that detects a saturation temperature of the condenser, and evaporation temperature detection means that detects the saturation temperature of the evaporator are provided. Operation efficiency is estimated by a value obtained by dividing heating ability estimated from a detection value of the condensation temperature detection means by a difference between a detection value of condensation temperature detection means and that of evaporation temperature detection means or dissipation power estimated by the difference.

Abstract: Methods and systems are provided for controlling a defrost unit for a vehicle. A prediction is performed as to whether condensation has formed against a surface of the vehicle. The defrost unit is automatically activated when it is predicted that the condensation has formed against the surface. Another prediction is made as to whether condensation has dissipated from the surface while the defrost unit is operating. The defrost unit is automatically deactivated when it is predicted that the condensation has dissipated.

Abstract: Frost may accumulate on a heat pump. In various implementations, a primary defrost operation and/or a secondary defrost operation may be utilized to remove at least a portion of the frost from the heat pump.

Abstract: Adaptable evaporator defrost logic is employed in a refrigeration system to detect a build-up of ice on the evaporator. In response to the detected build-up of ice, a defrost operation is initiated that includes decreasing the speed of the compressor. At the end of the defrost operation, the adaptable evaporator defrost logic determines whether the defrost operation was a success. If the defrost operation was a success, then normal operation is resumed. If the defrost operation was not a success, then the defrost operation is modified by turning the compressor off and extending a duration of the defrost operation.

Abstract: An air conditioner includes a refrigerant circuit, a switching valve, an outdoor fan and a controller. The refrigerant circuit sequentially circulates refrigerant through a compressor, an indoor heat exchanger, a decompression mechanism and an outdoor heat exchanger during a heating operation. The switching valve is connected to the refrigerant circuit to switch a flow direction of the refrigerant discharged from the compressor. The controller executes a defrosting operation control in which the outdoor fan is deactivated and the switching valve directs refrigerant discharged from the compressor towards the outdoor heat exchanger during a defrosting operation. The controller further maintains the switching valve so refrigerant discharged from the compressor is directed towards the outdoor heat exchanger and executes a fan defrosting operation control in which the outdoor fan is rotated for a predetermined period of time after completion of the defrosting operation when a predetermined condition is satisfied.

Abstract: There is disclosed an electronic apparatus comprising a chip within a casing. A thermoelectric cooler has thermal connections to the chip and the casing and is configured to transport heat from the chip to the casing. A temperature measuring device is provided for determining the temperature of the chip. A control system is configured to maintain the chip at a target temperature by controlling current supplied to the thermoelectric cooler in response to the measured temperature. A temperature selection system is configured to select the chip target temperature dynamically on the basis of the casing temperature.

Abstract: An air conditioner for a vehicle includes: a compressor that compresses a heat exchange medium; an internal heat exchanger that performs heat exchange between the heat exchange medium expelled from the compressor and air for air conditioning introduced inside a vehicle compartment; and an external heat exchanger that performs heat exchange between the heat exchange medium expelled from the internal heat exchanger and external air, wherein the air conditioner for a vehicle calculates a temperature difference between an external air temperature and a discharge port temperature of the external heat exchanger, calculates an average value of the temperature difference, and performs a defrosting operation which melts frost adhered to the external heat exchanger when an amount of change of the average value is equal to or greater than a first predetermined value.

Abstract: Disclosed herein are a cooling apparatus and a control method thereof. The cooling apparatus using latent heat of a refrigerant includes evaporators evaporating the refrigerant, a compressor compressing the evaporated refrigerant to a high pressure, defrosting heaters removing frost accumulated on the evaporators, a driving unit providing driving current selectively to the compressor or the defrosting heaters, and a control unit controlling the driving unit to provide driving current to the compressor in a cooling operation mode and controlling the driving unit to provide driving current to the defrosting heaters in a defrosting operation mode. The cooling apparatus controls the defrosting heaters using a driving circuit controlling the compressor, and thus lowers the manufacturing costs of a refrigerator operated at DC power.

Abstract: An air conditioner is provided. The air conditioner includes a heat exchanger which exchanges heat with air by passing a coolant therethrough; and an anti-freeze apparatus which prevents the freeze of water on the surface of the heat exchanger by supplying energy to the heat exchanger. The air conditioner can prevent the freeze of water on the surface of the heat exchanger during its operation, and thus, there is no need to perform a defrost operation during the operation of the air conditioner. In addition, the air conditioner can continuously and efficiently perform an air conditioning function.

Abstract: A refrigeration cycle apparatus 100 includes a first compressor 101, a second compressor 102 provided in parallel with the first compressor 101, a radiator 103 for cooling a refrigerant compressed by the compressors 101 and 102, an expander 104 for recovering power while expanding the refrigerant cooled by the radiator 103, an evaporator 105 for evaporating the refrigerant expanded by the expander 104, a rotation shaft 123 connecting the first compressor 101 to the expander 104 so that the first compressor 101 uses the power recovered by the expander 104, a controller 112 for executing a control including a step of increasing a flow rate of the refrigerant gradually during a defrosting operation in which frost formed on the evaporator 105 is melted by allowing the refrigerant having a high temperature to flow through the evaporator 105.

Abstract: An air conditioner is provided. The air conditioner includes a heat exchanger which exchanges heat with air by passing a coolant therethrough; an anti-freeze apparatus which prevents the freeze of water on the surface of the heat exchanger by supplying energy to the heat exchanger; and a control unit which controls the anti-freeze apparatus according to operating conditions of the air conditioner. Therefore, the air conditioner can effectively prevent the freeze of water, if any, on the surface of the heat exchanger.

Abstract: A refrigerator is provided that includes a chilled interior and a cooling circuit for a coolant, the cooling circuit being provided with an evaporator, a compressor, and a condenser. The refrigerator further includes a controller as well as a fan for cooling the condenser and the compressor. The controller controls the fan to operate during an idle phase of the compressor.

Abstract: A heat pump system includes a controller and a closed system that includes a condensing heat exchanger coil, an evaporating heat exchanger coil, a refrigerant and a compressor. The compressor is configured to compress the refrigerant, thereby causing the refrigerant to have a greater pressure in the condensing heat exchanger coil than in the evaporating heat exchanger coil. The controller is configured to perform a passive defrost of the evaporating heat exchanger coil. The passive defrost includes disabling the compressor and providing a bypass path between the condensing and evaporating heat exchanger coils that bypasses the compressor. The bypass path allows the refrigerant to flow from the condensing heat exchanger coil to the evaporating heat exchanger coil while the compressor is disabled.

Abstract: An air conditioner is provided. The air conditioner includes a heat exchanger which exchanges heat with air by passing a coolant therethrough; an anti-freeze apparatus which prevents the freeze of water on the surface of the heat exchanger by supplying energy to the heat exchanger; and a heat generation unit which heats the heat exchanger. The air conditioner can minimize the need for a defrost operation and can thus continuously and effectively perform an air conditioning function even when water on the surface of the heat exchanger is frozen.

Abstract: A method for defrost control of a refrigerator having a refrigeration and defrost system that includes a compressor, an evaporator, an evaporator fan and a heater. The refrigerator also has a control system to control the operation of the refrigerator. The method includes stopping the compressor operation; starting a defrost process; starting the heater; maintaining a start state over a preset period of time; closing off the heater; and starting the compressor. After starting the compressor and before the evaporator fan is started to perform the refrigeration operation, the evaporator fan is operated at least once briefly and intermittently.

Abstract: When the temperatures of outdoor heat exchangers 23a and 23b detected by outdoor heat exchanger temperature sensors 57a and 57b become equal to or higher than 5 degrees C. and the sucking superheating degrees of compressors 21a and 21b become equal to or lower than 0 degrees C. while an air conditioning apparatus 1 is performing the reverse defrosting operation, the reverse defrosting operation is stopped and the heating dominant operation is resumed. At this time, the total operating times of the compressors 21a and 21b are reset. The sucking superheating degrees of the compressors 21a and 21b are obtained by subtracting the low pressure saturation temperatures calculated from the sucking pressures of the compressors 21a and 21b, from the temperatures of the refrigerants sucked into the compressors 21a and 21b which temperatures are detected by the sucking temperature sensors 54a and 54b.

Abstract: An air conditioner (1) includes: a compressor (21); an outdoor heat exchanger (23); an indoor heat exchanger (13); an outdoor fan (25); and an indoor fan (15). In a case where the outdoor heat exchanger (23) has frost, the indoor fan (15) and the outdoor fan (25) are stopped, and a refrigerant is flowed in a direction opposite to a warming operation so as to perform a defrosting operation. In a case where a temperature of the refrigerant output from the compressor (21) declines below a predetermined temperature during the defrosting operation, it is determined to be defective defrosting. In a case of the defective defrosting by the defrosting operation, the outdoor fan (25) is driven, the indoor fan (15) is stopped and the refrigerant is flowed in a same direction as the warming operation so as to perform a defrosting preparation operation. Thereafter, the defrosting operation is resumed.

Abstract: A conduit used only at one end of, and mildly defrosting, an evaporator without causing excessive heat to affect the evaporator in proximity to the evaporator. A tube includes at least one central passageway, at least one peripheral passageway, and at least one intermediate passageway. A refrigerant flows through the at least one peripheral passageway. A hot refrigerant gas flows through the at least one central passageway, and blends with the refrigerant flowing through the tube so as to form a defrosting blend. The defrosting blend defrosts along the full length of the tube, which occurs very rapidly due to contact of the hot refrigerant gas on the way to the end of the tube and then back through the at least one intermediate passageway of the tube as the blend.

Abstract: Methods and apparatus for an energy efficient freezer or cooler defrost, which are particularly suited for an automated system, include procedures utilized for this purpose. The procedures are included in the firmware of an embedded controller and operate the cooler or freezer defrost cycle when required for increased energy efficiency.

Abstract: A high performance refrigerator or freezer includes a cabinet with a refrigerated interior, a first evaporator cover separating a first evaporator compartment within the cabinet from the refrigerated interior, and a refrigeration fluid circuit having a first evaporator located within the first evaporator compartment, a second evaporator, and a three-way valve enabling selective communication of refrigerant to one or both of the evaporators. The second evaporator includes an air diffuser that receives chilled air from the first evaporator compartment and delivers the chilled air into the refrigerated interior. During normal operation, the three-way valve only directs refrigerant into the first evaporator such that the first evaporator cools the cabinet and the chilled air from the first evaporator passively defrosts the second evaporator by sublimation.

Abstract: A high performance refrigerator includes a cabinet with a refrigerated interior, a refrigeration fluid circuit having an evaporator located within an insulated evaporator compartment outside the cabinet, and at least one damper that opens to permit air circulation from the refrigerated interior through the evaporator compartment. The refrigerator also includes a eutectic member configured to melt at an operating temperature of the refrigerator. The evaporator cools the refrigerated interior to a temperature below the operating temperature so that the eutectic member melts to cool the refrigerated interior or the evaporator compartment during a defrost cycle. The insulated evaporator cover limits heat transfer into the refrigerated interior during the defrost cycle to avoid temperature spikes in the refrigerated interior.

Abstract: A high performance refrigerator includes a cabinet with a refrigerated interior, an insulating cover separating a portion of the cabinet from the refrigerated interior, and a refrigeration fluid circuit having an evaporator located within the portion of the cabinet separated by the insulating cover from the refrigerated interior. The refrigerator also includes a controller that commands the refrigerator to perform a defrosting cycle when the evaporator coil requires defrosting. This defrosting cycle includes closing dampers in the insulating cover during the defrosting of the evaporator coil, thereby keeping the refrigerated interior thermally isolated from the evaporator during the defrost cycle. The controller is also operable to stop operation of a defrost heater when the evaporator reaches a first target temperature above the freezing point of water, and to re-open the dampers when the evaporator reaches a second target temperature above the freezing point of water.