Patent Description:
Many residential refrigerators also include as a convenience feature an integrated dispenser for dispensing a fluid (e.g., water) and/or ice. Such dispensers may also be externally accessible, and often include a sump or tray that collects any dispensed ice and/or water that has dripped or spilled from the dispenser during or after dispensing ice and/or water into a container. Dispensers are also prone to condensation in some instances, particularly when ice is being dispensed and cold air is expelled from the dispenser with the ice.

Condensation generally forms on a surface whenever the temperature of the surface drops below the dew point of the air surrounding the surface, and as a result, many refrigerators incorporate various heating devices capable of supplying heat to various surfaces to inhibit condensation. Heat generated by the condenser of a refrigerator cooling system as an inherent byproduct of the refrigeration process may be used in some areas of a refrigerator (e.g., via tubing extensions from the condenser); however, in many areas of a refrigerator, particularly on the doors or on other moving parts in a refrigerator, electric heaters are used to heat surfaces that are potentially subject to condensation. The use of electric heaters, however, increases energy consumption, so it is generally desirable to limit the use of such heaters only to circumstances where condensation has or is likely to be formed. Conventional refrigerators, however, rely either on user selection of an energy saver function or on preprogrammed algorithms that run generally any time the cooling system is active. In either case, however, a risk exists that condensation may occur.

Prior art document <CIT> discloses a refrigerator including a storage compartment and a mullion assembly pivotally coupled to one of a first door and a second door. The mullion assembly includes a cavity with an insulating member disposed therein. One or more sensor assemblies are coupled to the mullion assembly and configured to collect data sufficient to calculate a dew point temperature of the mullion assembly and an actual temperature of the mullion assembly. A heating element is coupled to the mullion assembly and is selectively activated by a controller based on information provided from the one or more sensor assemblies. The heating element is powered using a modulated power level that is inversely proportionate to the difference in temperature between the mullion assembly and the calculated dew point.

Prior art document <CIT> discloses an apparatus for sensing and removing dew on a refrigerator. The apparatus may include a heater disposed at a refrigerator body or inside a surface of a door, and a sensor disposed in close proximity to the heater. The sensor may be configured to sense dew formed on a prescribed surface at the refrigerator body or the door. The sensor may be disposed physically separate from the prescribed surface to sense formation of dew on the prescribed surface. The heater is controlled to generate heat that removes the sensed dew on the prescribed surface based on a signal from the sensor.

Prior art document <CIT> discloses a temperature-sensor having a sharply positive "temperature-resistance" characteristic in an inadequate relative humidity range, installed in at least one of the doors or its surrounding parts, and having a thyristor at its direct-draught end connected to an AC power supply through a diode bridge circuit. The humidity detector is connected between the gate of the thyristor and the canode, and the change in resistance of the detected humidity value triggers the thyristor to control the energization of the dew-impermeant heater.

The herein-described embodiments address these and other problems associated with the art by utilizing a dynamic multi-zone anti-sweat heating system in a refrigerator to reduce moisture on various surfaces of the refrigerator. Moreover, in some instances, the determination of when moisture is present and/or absent from a surface may be made based at least in part on detection of the presence or absence of an elevated thermal load on the surface while a heater is activated.

Therefore, consistent with one aspect of the invention, a refrigerator may include a cabinet including one or more food compartments and one or more doors providing external access to the one or more food compartments, a surface heater positioned to heat a surface of the cabinet, a temperature sensor positioned to sense a temperature for the surface, and a controller coupled to the surface heater and the temperature sensor, the controller configured to detect moisture on the surface by activating the surface heater, sensing temperature with the temperature sensor, and determining that moisture is present on the surface in response to detecting an elevated thermal load on the surface while the surface heater is activated. The refrigerator further includes an externally mounted dispenser disposed on the cabinet and a dispenser recess sump, and the surface is disposed on the dispenser recess sump.

Some embodiments may also include an articulating mullion disposed on one of the one or more doors, and the surface is disposed on the articulating mullion. Also, in some embodiments, the controller is further configured to generate an alert indicating that a door among the one or more doors has been left open in response to a temperature sensed by the temperature sensor. Further, in some embodiments, the controller is further configured to generate an alert indicating that a gasket of a door among the one or more doors may be disrupted in response to a temperature sensed by the temperature sensor.

In some embodiments, the controller is further configured to generate an alert indicating a presence of fluid in the dispenser recess sump in response to a temperature sensed by the temperature sensor.

In addition, in some embodiments, the surface is a first surface, the surface heater is a first surface heater, the temperature sensor is a first temperature sensor, the refrigerator further includes a second surface heater positioned to heat a second surface in a dispenser recess and a second temperature sensor positioned to sense a temperature for the second surface, and the controller is further configured to separately activate the first and second surface heaters based upon moisture respectively detected on the first and second surfaces.

In some embodiments, the surface is a first surface, the surface heater is a first surface heater, the temperature sensor is a first temperature sensor, the refrigerator further includes a second surface heater positioned to heat a second surface of the cabinet and a second temperature sensor positioned to sense a temperature for the second surface, and the controller is further configured to detect moisture on the second surface and to separately activate the first and second surface heaters based upon moisture respectively detected on the first and second surfaces. Some embodiments may also include an evaporative tray disposed on the cabinet, and the surface is disposed on the evaporative tray.

In some embodiments, the controller is configured to determine the elevated thermal load based upon a rate of temperature rise during activation of the surface heater. In addition, in some embodiments, the controller is configured to determine the elevated thermal load based upon a comparison of temperature rise with applied current to the heater.

Moreover, in some embodiments, the controller is further configured to predict a likelihood of condensation forming on the surface based upon the temperature sensed by the temperature sensor, and to activate the surface heater in response to predicting that condensation is likely to be forming on the surface. In some embodiments, the controller is further configured to predict the likelihood of condensation forming on the surface based upon ambient temperature and/or humidity sensed by one or more additional sensors of the refrigerator. Moreover, in some embodiments, the controller is configured to predict the likelihood of condensation by executing a prediction algorithm, and the controller is configured to dynamically execute the prediction algorithm in response to consumer or appliance behavior.

In some embodiments, the controller is configured to dynamically execute the prediction algorithm in response to detected ice retrieval, detected door opening, occupancy monitoring, sealed system cycling, fan operation and/or ice production. In addition, in some embodiments, the controller is configured to predict the likelihood of condensation by executing a prediction algorithm, and the controller is configured to dynamically execute the prediction algorithm in response to ambient monitoring or input received from an HVAC system. In some embodiments, the temperature sensor is integrated into the surface heater.

Consistent with another aspect of the invention, a refrigerator may include a cabinet including one or more food compartments and one or more doors providing external access to the one or more food compartments, a plurality of surface heaters positioned to heat respective surfaces among a plurality of surfaces of the cabinet, a plurality of temperature sensors positioned to sense temperatures for respective surfaces among the plurality of surfaces, and a controller coupled to the plurality of surface heaters and the plurality of temperature sensors, the controller configured to detect moisture on a selected surface of the plurality of surfaces by activating the respective surface heater for the selected surface, sensing temperature with the respective temperature sensor for the selected surface, and determining that moisture is present on the selected surface in response to detecting an elevated thermal load on the selected surface while the surface heater for the selected surface is activated.

These and other advantages and features, which characterize the invention, are set forth in the claims annexed hereto and forming a further part hereof. However, for a better understanding of the invention, and of the advantages and objectives attained through its use, reference should be made to the Drawings, and to the accompanying descriptive matter, in which there is described example embodiments of the invention. This summary is merely provided to introduce a selection of concepts that are further described below in the detailed description, and is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.

Turning now to the drawings, wherein like numbers denote like parts throughout the several views, <FIG> illustrates an example refrigerator <NUM> in which the various technologies and techniques described herein may be implemented. Refrigerator <NUM> is a residential-type refrigerator, and as such includes a cabinet <NUM> including a main case <NUM> housing one or more food storage compartments (e.g., a fresh food compartment <NUM> and a freezer compartment <NUM>), as well as one or more fresh food compartment doors <NUM>, <NUM> and one or more freezer compartment doors <NUM> disposed adjacent respective openings of food storage compartments <NUM>, <NUM> and configured to insulate the respective food storage compartments <NUM>, <NUM> from an exterior environment when the doors are closed.

Fresh food compartment <NUM> is generally maintained at a temperature above freezing for storing fresh food such as produce, drinks, eggs, condiments, lunchmeat, cheese, etc. Various shelves, drawers, and/or sub-compartments may be provided within fresh food compartment <NUM> for organizing foods, and it will be appreciated that some refrigerator designs may incorporate multiple fresh food compartments and/or zones that are maintained at different temperatures and/or at different humidity levels to optimize environmental conditions for different types of foods. Freezer compartment <NUM> is generally maintained at a temperature below freezing for longer-term storage of frozen foods, and may also include various shelves, drawers, and/or sub-compartments for organizing foods therein.

Refrigerator <NUM> as illustrated in <FIG> is a type of bottom mount refrigerator commonly referred to as a French door refrigerator, and includes a pair of side-by-side fresh food compartment doors <NUM>, <NUM> that are hinged along the left and right sides of the refrigerator to provide a wide opening for accessing the fresh food compartment, as well as a single sliding freezer compartment door <NUM> that is similar to a drawer and that pulls out to provide access to items in the freezer compartment. It will be appreciated, however, that other door designs may be used in other embodiments, including various combinations and numbers of hinged and/or sliding doors for each of the fresh food and freezer compartments. Moreover, while refrigerator <NUM> is a bottom mount refrigerator with freezer compartment <NUM> disposed below fresh food compartment <NUM>, the invention is not so limited, and as such, the principles and techniques may be used in connection with other types of refrigerators in other embodiments.

Refrigerator <NUM> also includes a door-mounted dispenser <NUM> for dispensing ice and/or a fluid such as water. In the illustrated embodiments, dispenser <NUM> is an ice and water dispenser capable of dispensing both ice (cubed and/or crushed) and chilled water, while in other embodiments, dispenser <NUM> may be an ice only dispenser for dispensing only cubed and/or crushed ice, or a water only dispenser for dispensing only water. In still other embodiments, dispenser <NUM> may dispense hot water, coffee, beverages, or other fluids, and may have variable and/or fast dispense capabilities, as well as an ability to dispense predetermined or measured quantities of fluids. In some instances, ice and water may be dispensed from the same location, while in other instances separate locations may be provided in the dispenser for dispensing ice and water.

Refrigerator <NUM> also includes a control panel <NUM>, which in the illustrated embodiment is integrated with dispenser <NUM> on door <NUM>, and which includes various input/output controls such as buttons, indicator lights, alphanumeric displays, dot matrix displays, touch-sensitive displays, etc. for interacting with a user. In other embodiments, control panel <NUM> may be separate from dispenser <NUM> (e.g., on a different door), and in other embodiments, multiple control panels may be provided. Further, in some embodiments audio feedback may be provided to a user via one or more speakers, and in some embodiments, user input may be received via a spoken or gesture-based interface. Additional user controls may also be provided elsewhere on refrigerator <NUM>, e.g., within fresh food and/or freezer compartments <NUM>, <NUM>. In addition, refrigerator <NUM> may be controllable remotely, e.g., via a smartphone, tablet, personal digital assistant or other networked computing device, e.g., using a web interface or a dedicated app.

Furthermore, as will be discussed in greater detail below, dispenser <NUM> may additionally include a dispenser recess sump <NUM> that is used to capture ice, water, or other fluids dispensed from dispenser <NUM>. As will also be discussed in greater detail below, dispenser recess sump <NUM> may retain a volume of fluid for which it may be desirable to remove, e.g., through evaporation. In addition, due to the fact that cold water and ice may be dispensed by dispenser <NUM>, as well as the fact that the dispenser recess (i.e., the portion under the dispenser outlet(s) that is recessed within door <NUM>) is potentially exposed to lower temperatures and thus a greater risk of condensation, it may be desirable to incorporate an anti-sweat heating capability for the dispenser.

A refrigerator consistent with the invention also generally includes one or more controllers configured to control a refrigeration system as well as manage interaction with a user. <FIG>, for example, illustrates an example embodiment of a refrigerator <NUM> including a controller <NUM> that receives inputs from a number of components and drives a number of components in response thereto. Controller <NUM> may, for example, include one or more processors <NUM> and a memory <NUM> within which may be stored program code for execution by the one or more processors. The memory may be embedded in controller <NUM>, but may also be considered to include volatile and/or nonvolatile memories, cache memories, flash memories, programmable read-only memories, read-only memories, etc., as well as memory storage physically located elsewhere from controller <NUM>, e.g., in a mass storage device or on a remote computer interfaced with controller <NUM>. Controller <NUM> may also be distributed among multiple controller circuits within refrigerator <NUM> in some embodiments, so the invention should not be considered to be limited to a controller implemented as a single central controller circuit as is illustrated in <FIG>.

As shown in <FIG>, controller <NUM> may be interfaced with various components, including a cooling or refrigeration system <NUM>, an ice and water system <NUM>, one or more user controls <NUM> for receiving user input (e.g., various combinations of switches, knobs, buttons, sliders, touchscreens or touch-sensitive displays, microphones or audio input devices, image capture devices, etc., as well as one or more variable controls as discussed in greater detail below), and one or more user displays <NUM> (including various indicators, graphical displays, textual displays, speakers, etc.), as well as various additional components suitable for use in a refrigerator, e.g., interior and/or exterior lighting <NUM>, among others.

Controller <NUM> may also be interfaced with various sensors <NUM> located to sense environmental conditions inside of and/or external to refrigerator <NUM>, e.g., one or more temperature sensors, humidity sensors, etc. Such sensors may be internal or external to refrigerator <NUM>, and may be coupled wirelessly to controller <NUM> in some embodiments. In addition, controller <NUM> may be interfaced with one or more heaters <NUM>, e.g., for use in a dynamic multi-zone anti-sweat heating system as described in greater detail herein.

In some embodiments, controller <NUM> may also be coupled to one or more network interfaces <NUM>, e.g., for interfacing with external devices via wired and/or wireless networks such as Ethernet, Wi-Fi, Bluetooth, NFC, cellular and other suitable networks, collectively represented in <FIG> at <NUM>. Network <NUM> may incorporate in some embodiments a home automation network, and various communication protocols may be supported, including various types of home automation communication protocols. In other embodiments, other wireless protocols, e.g., Wi-Fi or Bluetooth, may be used.

In some embodiments, refrigerator <NUM> may be interfaced with one or more user devices <NUM> over network <NUM>, e.g., computers, tablets, smart phones, wearable devices, etc., and through which refrigerator <NUM> may be controlled and/or refrigerator <NUM> may provide user feedback. Refrigerator <NUM> may also be interfaced in some embodiments with one or more remote services <NUM>, e.g., various cloud or remote computing services.

In some embodiments, controller <NUM> may operate under the control of an operating system and may execute or otherwise rely upon various computer software applications, components, programs, objects, modules, data structures, etc. In addition, controller <NUM> may also incorporate hardware logic to implement some or all of the functionality disclosed herein. Further, in some embodiments, the sequences of operations performed by controller <NUM> to implement the embodiments disclosed herein may be implemented using program code including one or more instructions that are resident at various times in various memory and storage devices, and that, when read and executed by one or more hardware-based processors, perform the operations embodying desired functionality. Moreover, in some embodiments, such program code may be distributed as a program product in a variety of forms, and that the invention applies equally regardless of the particular type of computer readable media used to actually carry out the distribution, including, for example, non-transitory computer readable storage media. In addition, it will be appreciated that the various operations described herein may be combined, split, reordered, reversed, varied, omitted, parallelized and/or supplemented with other techniques known in the art, and therefore, the invention is not limited to the particular sequences of operations described herein.

Numerous variations and modifications to the refrigerator illustrated in <FIG> will be apparent to one of ordinary skill in the art, as will become apparent from the description below. Therefore, the invention is not limited to the specific implementations discussed herein.

Some embodiments consistent with the invention, as mentioned above, are directed in part to the use of a dynamic multi-zone anti-sweat heating system for inhibiting the formation of moisture on various surfaces of a refrigerator and/or to evaporate fluid collected in a refrigerator, e.g., in a dispenser recess sump, evaporative tray, or other fluid collection structure.

An anti-sweat heating system may be considered to be dynamic from the standpoint that, at least in some embodiments, the heating system is capable of dynamically activating one or more heaters in response to detection of the presence of moisture on a surface, or at least detection of conditions that are indicative of a likely presence of moisture on a surface. An anti-sweat heating system may be considered to be multi-zone from the standpoint that, at least in some embodiments, multiple individually-actuatable zones exist that can be independently monitored and activated to address potential moisture within such zones.

A zone, in particular, may include one or more heaters and one or more temperature sensors, and may cover one or more interior and/or exterior surfaces of a refrigerator cabinet (which, for the purposes of this disclosure, may include both the main case and the doors of the refrigerator, as well as any other component or structure in the refrigerator upon which it may be desirable to prevent condensation from forming and/to or evaporate any condensation or fluid that may exist). As such, in some embodiments a zone may encompass multiple surfaces, while in other embodiments one surface may have multiple zones.

The heaters in a zone may be heating elements capable of heating associated surfaces, and the temperature sensors may be surface temperature sensors capable of sensing a temperature on associated surfaces. Multiple heating elements within a zone may be supported in some embodiments, and the multiple heating elements may be disposed in the same heating assembly in some embodiments, or may be disposed in different heating assemblies. Further, in some embodiments, the heating elements may be considered to be surface heaters to the extent that the heat generated thereby provides heat to an associated surface. In addition, it will be appreciated that multiple zones may operate in a group in some embodiments, such that activities occurring within multiple zones of a group may be affect the activation of the heating elements in various zones in the group (e.g., as is the case with a dispenser recess as discussed below in connection with <FIG>).

By utilizing multiple zones, each zone may be provided with individual temperature feedback, and the temperature feedback may be used to enable a controller to dynamically react to sensed temperature by selectively activating heaters. As such, in some embodiments zones may be monitored on an ongoing basis, with heaters activated on demand when needed, and only in zones within which moisture may be present, thereby minimizing overall energy usage.

In some embodiments, activation of a heater in a zone may be based on a dew point determined, for example, from a sensed ambient relative humidity, along with one or more surface temperature readings that detect when a surface temperature drops below a calculated dew point. In other embodiments, the temperature in each zone may be monitored to detect drops in temperature, which may be indicative of heat flux, and indicating the desirability of energizing a heater in a particular zone.

Furthermore, in some embodiments, moisture detection (and/or detection of removal of moisture) may be based in part on the evaporative cooling effect of moisture. In particular, in some embodiments moisture detection may be based at least in part on sensing the thermal load on a surface, in particular while a heater associated with the surface is active, as moisture present on a surface will generally present as a thermal mass that, when heated, will resist an increase in surface temperature as a result of the phase change occurring as the moisture evaporates. This resistance to change may be sensed, for example, by monitoring the rate of change of the sensed surface temperature, or alternatively by comparing a rate of change of the sensed surface temperature to an amount of applied current to a heater (e.g., by dividing temperature increase by applied amperage in some embodiments). Moisture may therefore be detected based upon a reduced or slower than expected rise in temperature when a heater is activated (i.e., an increased thermal load), while the evaporation of moisture may be detected based upon a transition to a faster temperature rise when a heater is activated (i.e., a decreased thermal load). Further, the detection of moisture in one zone or on one surface or portion of a surface could be used to trigger activation of heaters in other zones or associated with other surfaces, given that environmental conditions particularly suitable for condensation may have been detected.

Thus, in some embodiments consistent with the invention, a controller coupled to a heater and a temperature sensor may be able to detect moisture on a surface by activating the heater, sensing a surface temperature with the temperature sensor while the heater is activated, and determining that moisture is present on the surface in response to detecting an elevated thermal load on the surface while the surface heater is activated.

It will also be appreciated that, in addition to or in lieu of condensation formed on interior and/or exterior surfaces of a refrigerator, the techniques described herein may also be used to accelerate the evaporation of fluids collected in various receptacles in a refrigerator, e.g., a dispenser recess sump and/or an evaporative tray used to collect condensation generated by a refrigerator cooling system. In particular, heaters may be used to accelerate fluid evaporation, and monitored surface temperatures may be used to detect when fluid is present and/or when all of the fluid in a receptacle has been removed.

Now turning to <FIG>, it will be appreciated that a dynamic multi-zone anti-sweat heating system may be used in a number of different areas and applications within a refrigerator. <FIG> in particular illustrates door <NUM> of refrigerator <NUM> in greater detail, along with several potential zones that may be utilized in a heating system consistent with the invention.

One potential application of such a heating system is in connection with addressing condensation on an articulating mullion of a refrigerator door. Door <NUM>, for example, is illustrated in <FIG> with an articulating mullion <NUM> including a pair of heaters <NUM>, <NUM> and associated temperature sensors <NUM>, <NUM> effectively defining two different zones on the articulating mullion <NUM>, and suitable for addressing potential moisture condensation on the mullion, e.g., when the door is open. In addition, for dispenser recess sump <NUM>, an associated heater <NUM> and temperature sensor <NUM> are illustrated, e.g., for evaporating fluids collected in the sump <NUM>. Furthermore, for the recess of dispenser <NUM> itself, an additional zone may be defined including a heater <NUM> formed along a back wall of the recess, and proximate to a dispenser outlet from which cold air may escape and potentially cause an increase in the likelihood of condensation. <FIG> also illustrates that in some embodiments, a zone may include multiple temperature sensors, e.g., temperature sensors <NUM> disposed at different locations in the recess. Further, <FIG> also illustrates that in some embodiments, a heater such as heater <NUM> may include multiple heating elements <NUM>, which may be separately or collectively activated in various embodiments.

<FIG> illustrates an additional location for a zone in refrigerator <NUM>, in particular, on the rear <NUM> of the refrigerator, where an evaporative tray <NUM> utilized by the cooling system may be located. A heater <NUM> and associated temperature sensor <NUM> may be used to accelerate evaporation of fluids collected in tray <NUM>.

It will be appreciated that the various applications illustrated in <FIG> and <FIG> are merely exemplary in nature, and that the techniques disclosed herein may be used in a wide variety of other applications, including, without limitation, interior and/or exterior surfaces of the case or doors, internal mullions, defrost heaters, duct door heaters, and compartment heaters (e.g., quick thaw compartments), among others.

Now turning to <FIG>, an example dynamic multi-zone anti-sweat heating system <NUM> is illustrated in greater detail, and suitable for implementation, for example, in refrigerator <NUM>. A controller <NUM> in particular is coupled to multiple zones <NUM>, each including one or more heaters <NUM> and one or more temperature sensors <NUM>. Each heater may be implemented using a number of different technologies suitable for the particular application of a zone. For example, resistive heating elements may be printed on flexible substrates or directly on or underneath a surface in some embodiments, while in other embodiments, other heating technologies, e.g., thick film heaters, resistance wire heaters, etc. may be used. Each temperature sensor <NUM> is generally configured to sense a surface temperature near or on a surface being monitored, and in some instances, a temperature sensor <NUM> may be integrated directly into a heater assembly. In other instances, however, each temperature sensor may be separate from any heater, but disposed in proximity thereto.

Controller <NUM> may utilize temperature sensors <NUM> to monitor surface temperatures for the purpose of determining when to dynamically activate and/or deactivate the associated heaters <NUM> in a zone <NUM>. In addition to or in lieu of temperature sensors <NUM>, however, various additional inputs may be used in a dynamic multi-zonal anti-sweat heating system consistent with the invention. For example, an ambient temperature sensor <NUM> and/or ambient humidity sensor <NUM> may be used to determine the temperature and/or humidity of the environment within which the refrigerator is installed. In addition, input may be provided from a cooling system <NUM>, e.g., indicating when the cooling system is currently active. Door switches <NUM> may be used to determine the open/closed status of various doors in the refrigerator, while a dispensing system <NUM> may provide information such as whether ice and/or water is currently being dispensed, whether an ice duct door is open, etc. Further, in some embodiments, a motion sensor <NUM> may be used to detect occupancy in the room in which the refrigerator is installed. Still further, in some embodiments, input may be received from various external devices, e.g., from an HVAC system through a network interface <NUM>, whereby controller <NUM> may receive information such as whether the HVAC is currently running, to which temperature setpoint the HVAC system is currently set, ambient temperature and/or humidity sensed by the HVAC system, etc. In still other embodiments, weather information may be received over network interface <NUM>, e.g., from a remote service, so that controller <NUM> may account for upcoming changes in weather such as storms that could change ambient conditions over the near future. It will be appreciated that in some embodiments, many of the aforementioned inputs may be omitted, so the invention is not limited to the particular combination of inputs illustrated in <FIG>.

<FIG> illustrates an example sequence of operations <NUM> for dynamically monitoring and activating zones in heating system <NUM> of <FIG>. Sequence <NUM> may be executed for all or multiple zones, for an entire heater, an entire zone, or individual heating elements within a larger array or heater. Periodically, as illustrated in block <NUM>, a temperature datapoint is captured for each zone, representing a surface temperature sensed by the temperature sensor(s) for that zone. A surface condensation likelihood is then predicted or calculated in block <NUM>, e.g., using a prediction algorithm based upon the captured datapoints, and as represented by block <NUM>, also optionally based upon ambient temperature and/or humidity sensed by sensors <NUM>, <NUM>. Block <NUM>, in particular, may calculate a dew point in some embodiments, and then compare a surface temperature sensed for each zone with the calculated dew point, thereby determining whether the surface temperature of one or more zones is at or below the calculated dew point, representing conditions where condensation could occur. It will be appreciated that dew point may be calculated in a number of manners in different embodiments, and may be based on ambient temperature and/or humidity as sensed by sensors <NUM>, <NUM>, as provided by an HVAC system <NUM> or via weather data. Furthermore, the frequency at which the prediction algorithm is executed may vary in different embodiments, e.g., based upon consumer behavior, such as when ice is being retrieved (based upon dispensing system <NUM>), whether doors are open or closed (based on door switches <NUM>), or occupancy monitoring (based on motion sensor <NUM>) and/or based on appliance behavior, such as when the cooling system and/or fans are running (based on cooling system <NUM>), during sealed system cycling, when ice is being produced (based on dispensing system <NUM>), etc..

Moreover, the prediction algorithm may calculate a likelihood (e.g., in terms of a percentage) to allow for a greater or lesser chance of activating heaters, and in some instances, an energy saving function may be used to vary the prediction algorithm based upon whether or not the energy saving function is activated, e.g., to allow a greater chance of moisture and/or a lower chance of heaters being activated. A prediction algorithm may be based on a machine learning model in some embodiments, while in other embodiments, rule-based or procedural algorithms may instead be used. In many instances, however, and regardless of how implemented the likelihood of condensation may be predicted at least in part on a surface temperature measurement of a surface, so that a heater proximate to that surface may be activated whenever condensation is determined to be likely.

Thus, after the likelihood of surface condensation is predicted in block <NUM>, block <NUM> either returns control to block <NUM> if no surface condensation is predicted, or passes control to block <NUM> to energize the heaters or heating elements in any affected zones (i.e., zones where condensation is determined to be likely). Thereafter, block <NUM> monitors the thermal load in each energized zone, and block <NUM> determines if evaporation has completed in any energized zone. As noted above, based upon the evaporative cooling effect, heat applied by a heater will increase the surface temperature more slowly when moisture is present on a surface as energy is expended on the phase change from liquid to gas. Thus, by monitoring for temperature spikes during activation of a heater (e.g., based on temperature sensing and/or determining a temperature rise/amperage applied ratio), the evaporation of moisture can be detected. As such, for any zone where evaporation completion is detected, block <NUM> may pass control to block <NUM> to deactivate the heater(s) in that zone, and block <NUM> may then determine if any other zones are still active. Returning to block <NUM>, if no evaporation completion is detected in any zone, block <NUM> is bypassed and control passes directly to block <NUM>.

If any zones are still active, block <NUM> returns control to block <NUM> to continue to monitor the thermal load in each energized zone. Then, once all zones have been deenergized, block <NUM> returns control to block <NUM> to return to periodically running the prediction algorithm to detect when condensation is likely in one or more zones.

<FIG> and <FIG> next illustrate two practical applications of the herein described techniques, specifically with respect to a heating system for an articulating mullion (<FIG>) and a heating system for a dispenser recess (<FIG>). <FIG>, for example, illustrates a sequence of operations <NUM> for managing a heating zone on an articulating mullion having multiple heating zones covering different portions of the mullion (e.g., two or more zones), and which is triggered upon the detection of potential moisture in the zone in block <NUM> (e.g., as a result of running the prediction algorithm discussed above in connection with blocks <NUM>-<NUM> of <FIG>). If potential moisture in the zone is detected, block <NUM> determines whether the door is open (e.g., based upon the status of a door switch). If not, control passes to block <NUM> to determine if other zones have similarly detected the potential for moisture, and if so, control passes to block <NUM> to monitor the zone and activate the heater as necessary, e.g., using the operations described above in connection with blocks <NUM>-<NUM> of <FIG>). If, however, other zones are not sensing the potential for moisture, block <NUM> passes control instead to block <NUM> to perform further diagnostics, e.g., evaluating whether the compressor is running, whether other doors are open, whether any fans are running, etc., and potentially alerting a consumer or a service organization of a potential problem with the zone. The alert may take different forms in different embodiments, e.g., audible alerts such as beeps and/or synthesized speech, visual alerts such as indicator lights, LEDs, text and/or graphics on a display, or messages communicated to a remote device such as a mobile device, a cloud service, or other computing device. The alerts may be generated, for example, in response to determining that there may be problem with the door, the articulating mullion, or the heater in the zone being evaluated. Upon completion of either block <NUM> or block <NUM>, control returns to block <NUM> to wait for detection of potential moisture.

Returning to block <NUM>, if the door is determined to be opened, control passes to block <NUM> to continue to monitor the zone for potential moisture, specifically to determine if the moisture is sufficiently removed within a predetermined period of time (e.g., using the operations described above in connection with blocks <NUM>-<NUM> of <FIG>). If so, block <NUM> determines that the zone has recovered, and control returns to block <NUM>. If not, however, control passes to block <NUM> to determine if the issue is zonal, i.e., that the continued detection of moisture is not being sensed by all zones. If not zonal, meaning all zones are sensing the same conditions, it is possible that the door is still open, so control passes to block <NUM> to alert the consumer that the door may be open (e.g., using any of the audible, visual or message formats discussed above), then returning to block <NUM>. If zonal, however, control passes to block <NUM> to alert the consumer that a potential exists that the door gasket may be disrupted, and optionally, within which zone the disruption is predicted to exist. Control then returns to block <NUM>.

<FIG> illustrates a sequence of operations <NUM> for managing a heating zone in a dispenser recess sump, where an additional zone is provided elsewhere in the dispenser recess (e.g., on a back wall thereof), and which is triggered upon the detection of potential moisture in the zone in block <NUM> (e.g., as a result of running the prediction algorithm discussed above in connection with blocks <NUM>-<NUM> of <FIG>). If potential moisture in the zone is detected, block <NUM> determines whether the duct door for the dispenser is open (e.g., based upon the status of a duct door switch), which indicates that ice is currently being dispensed by the dispenser. If not, control passes to block <NUM> to determine if other zones (e.g., the other dispenser recess zone) have similarly detected the potential for moisture, and if so, control passes to block <NUM> to monitor the zone and activate the heater as necessary, e.g., using the operations described above in connection with blocks <NUM>-<NUM> of <FIG>). If, however, other zones are not sensing the potential for moisture, block <NUM> passes control instead to block <NUM> to perform further diagnostics, e.g., evaluating whether water is leaking or dribbling from the water dispenser, ice is melting or dripping from the ice dispenser, and potentially alerting a consumer or a service organization of a potential problem with the zone. The alert may take different forms in different embodiments, e.g., audible alerts such as beeps and/or synthesized speech, visual alerts such as indicator lights, LEDs, text and/or graphics on a display, or messages communicated to a remote device such as a mobile device, a cloud service, or other computing device. Upon completion of either block <NUM> or block <NUM>, control returns to block <NUM> to wait for detection of potential moisture.

Returning to block <NUM>, if the duct door is determined to be opened, and thus ice is currently being dispensed, control passes to block <NUM> to continue to monitor the zone for potential moisture, specifically to determine if the moisture is sufficiently removed within a predetermined period of time (e.g., using the operations described above in connection with blocks <NUM>-<NUM> of <FIG>). If so, block <NUM> determines that the zone has recovered, and control returns to block <NUM>. If not, however, control passes to block <NUM> to determine if the issue is zonal, i.e., that the continued detection of moisture is not being sensed by all zones, but only in the sump. If not only in the sump, it is possible that fogging is occurring within the recess, so control passes to block <NUM> to energize all of the zones in the dispenser recess to remove the fog, and control then returns to block <NUM> to wait for recovery. If only in the sump, however, the cause of the moisture may be the presence of fluids in the sump, so block <NUM> passes control to block <NUM> to energize the sump zone to evaporate any fluids retained within the sump. Control then returns to block <NUM> to wait for recovery, which occurs when the fluid has fully evaporated from the sump.

Claim 1:
A refrigerator, comprising:
a cabinet (<NUM>) including one or more food compartments (<NUM>, <NUM>) and one or more doors (<NUM>, <NUM>, <NUM>) providing external access to the one or more food compartments (<NUM>, <NUM>);
a surface heater (<NUM>) positioned to heat a surface of the cabinet (<NUM>);
a temperature sensor (<NUM>) positioned to sense a temperature for the surface; and
a controller (<NUM>) coupled to the surface heater (<NUM>) and the temperature sensor (<NUM>), the controller (<NUM>) configured to detect moisture on the surface by activating the surface heater (<NUM>), sensing temperature with the temperature sensor (<NUM>), and determining that moisture is present on the surface in response to detecting an elevated thermal load on the surface while the surface heater (<NUM>) is activated,
characterized in that,
the refrigerator further comprising an externally-mounted dispenser (<NUM>) disposed on the cabinet (<NUM>) and including a dispenser recess sump (<NUM>), wherein the surface is disposed on the dispenser recess sump (<NUM>).