DUAL COMPARTMENT TEMPERATURE MANAGEMENT SYSTEM UTILIZING A SINGLE EVAPORATOR IN A REFRIGERATOR APPLIANCE

Description

FIELD OF THE INVENTION

The present subject matter relates generally to refrigerator appliances, and more particularly to systems and methods for cooling multiple compartments in a refrigerator appliance.

BACKGROUND OF THE INVENTION

Refrigerator appliances generally include a cabinet that defines a chilled chamber for receipt of food articles for storage. In addition, refrigerator appliances include one or more doors rotatably hinged to the cabinet to permit selective access to food items stored in chilled chamber(s). The refrigerator appliances can also include various storage components mounted within the chilled chamber and designed to facilitate storage of food items therein. Such storage components can include racks, bins, shelves, or drawers that receive food items and assist with organizing and arranging of such food items within the chilled chamber.

Conventional refrigerator appliances have multiple chilled chambers and cooling systems that may independently regulate the temperatures within those chambers. However, these cooling systems typically include dedicated evaporators and evaporator plenums for each chamber. Alternatively, these cooling systems include complex systems of air dampers, air ducting systems, or other flow regulating features. These approaches utilize more components, resulting in complex assembly, increased costs, and more joints with opportunities for leaks. In addition, these cooling systems are often limited in temperature control between the compartments.

Accordingly, a refrigerator appliance with an improved cooling system would be useful. More particularly, a cooling system that effectively regulates the flow of cool air through multiple compartments with minimized components, complexity, and costs would be particularly beneficial.

BRIEF DESCRIPTION OF THE INVENTION

Aspects and advantages of the invention will be set forth in part in the following description, or may be apparent from the description, or may be learned through practice of the invention.

In one exemplary embodiment, a refrigerator appliance defining a vertical direction, a lateral direction, and transverse direction is provided, including a cabinet defining a first chilled chamber and a second chilled chamber, an evaporator compartment defining a first evaporator plenum and a second evaporator plenum, and a sealed system. The sealed system includes a compressor for urging a flow of refrigerant, a condenser fluidly coupled to the compressor, and an evaporator fluidly coupled to the compressor, the evaporator comprising a first evaporator coil positioned in the first evaporator plenum and a second evaporator coil positioned in the second evaporator plenum, wherein the first evaporator coil and the second evaporator coil share a single evaporator outlet.

In another exemplary embodiment, a temperature management system for a refrigerator appliance having a first chilled chamber and a second chilled chamber is provided. The temperature management system includes an evaporator compartment defining a first evaporator plenum and a second evaporator plenum and an evaporator comprising a first evaporator coil positioned in the first evaporator plenum and a second evaporator coil positioned in the second evaporator plenum, wherein the first evaporator coil and the second evaporator coil share a single evaporator outlet.

These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures.

FIG. 1 provides a perspective view of a refrigerator appliance according to an example embodiment of the present subject matter.

FIG. 2 provides a perspective view of the example refrigerator appliance of FIG. 1, with the doors of the fresh food chamber shown in an open position.

FIG. 3 provides a side, schematic view of a temperature management system that may be used with the example refrigerator appliance of FIG. 1 according to an example embodiment of the present subject matter.

FIG. 4 provides a front, schematic view of an evaporator of the example temperature management system of FIG. 3 according to an example embodiment of the present subject matter.

FIG. 5 provides a top, schematic view of a drain trough of the example temperature management system of FIG. 3 according to an example embodiment of the present subject matter.

FIG. 6 provides a front, schematic view of an evaporator of the example temperature management system of FIG. 3 according to another example embodiment of the present subject matter.

FIG. 7 provides a top, schematic view of a drain trough of the example temperature management system of FIG. 3 according to another example embodiment of the present subject matter.

Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the present invention.

DETAILED DESCRIPTION

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

As used herein, the terms “first,” “second,” and “third” may be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components. The terms “upstream” and “downstream” refer to the relative flow direction with respect to fluid flow in a fluid pathway. For example, “upstream” refers to the flow direction from which the fluid flows, and “downstream” refers to the flow direction to which the fluid flows. The terms “includes” and “including” are intended to be inclusive in a manner similar to the term “comprising.” Similarly, the term “or” is generally intended to be inclusive (i.e., “A or B” is intended to mean “A or B or both”).

Approximating language, as used herein throughout the specification and claims, is applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “about,” “approximately,” and “substantially,” are not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value. For example, the approximating language may refer to being within a 10 percent margin.

As explained herein, aspects of the present subject matter are generally directed to a method of cooling dual/multiple compartments using a single evaporator with multiple fans in a bottom freezer, quad-door refrigerator, or any other refrigerator or freezer appliance. The evaporator may include two capillary tube inlets and a single outlet location, where two branches of the outlet become a single outlet with the use of a Y-coupling or other suitable fluid coupling. The means of controlling refrigerant flow may be accomplished with a three-way valve and a single defrost heater may be used to defrost the entire evaporator at any time when defrost is initiated. The evaporator cover may include two fans to cool each compartment, and also contain features to separate the evaporator branches to prevent recirculation of airflow. The evaporator cover may incorporate ducting to deliver the airflow to the required locations within the individual compartments and the compartments may be separated by a removable mullion assembly. This allows the evaporator compartment assembly to be completed within the larger compartment, and then the mullion may be inserted to create two smaller compartments.

FIG. 1 provides a perspective view of a refrigerator appliance 100 according to an exemplary embodiment of the present subject matter. Refrigerator appliance 100 includes a housing or cabinet 102 that extends between a top 104 and a bottom 106 along a vertical direction V, between a first side 108 and a second side 110 along a lateral direction L, and between a front side 112 and a rear side 114 along a transverse direction T. Each of the vertical direction V, lateral direction L, and transverse direction T are mutually perpendicular to one another and form an orthogonal direction system.

Cabinet 102 defines chilled chambers for receipt of food items for storage. In particular, cabinet 102 defines fresh food chamber 122 positioned at or adjacent top 104 of cabinet 102 and a freezer chamber 124 arranged at or adjacent bottom 106 of cabinet 102. As such, refrigerator appliance 100 is generally referred to as a bottom mount refrigerator. It is recognized, however, that the benefits of the present disclosure apply to other types and styles of refrigerator appliances such as, e.g., a top mount refrigerator appliance, a side-by-side style refrigerator appliance, or a single door refrigerator appliance. Moreover, aspects of the present subject matter may be applied to other appliances as well, such as other appliances including fluid dispensers. Consequently, the description set forth herein is for illustrative purposes only and is not intended to be limiting in any aspect to any particular appliance or configuration.

Refrigerator doors 128 are rotatably hinged to an edge of cabinet 102 for selectively accessing fresh food chamber 122. In addition, a freezer door 130 is arranged below refrigerator doors 128 for selectively accessing freezer chamber 124. Freezer door 130 is coupled to a freezer drawer (not shown) slidably mounted within freezer chamber 124. To prevent leakage of cool air, refrigerator doors 128, freezer door 130, and/or cabinet 102 may define one or more sealing mechanisms (e.g., rubber gaskets, not shown) at the interface where the doors 128, 130 meet cabinet 102. It should be appreciated that doors having a different style, position, or configuration are possible within the scope of the present subject matter.

FIG. 2 provides a perspective view of refrigerator appliance 100 shown with refrigerator doors 128 in the open position. As shown in FIG. 2, various storage components are mounted within fresh food chamber 122 to facilitate storage of food items therein as will be understood by those skilled in the art. In particular, the storage components may include bins 134 and shelves 136. Each of these storage components are configured for receipt of food items (e.g., beverages and/or solid food items) and may assist with organizing such food items. As illustrated, bins 134 may be mounted on refrigerator doors 128 or may slide into a receiving space in fresh food chamber 122. It should be appreciated that the illustrated storage components are used only for the purpose of explanation and that other storage components may be used and may have different sizes, shapes, and configurations.

Referring again to FIG. 1, a dispensing assembly 140 will be described according to exemplary embodiments of the present subject matter. Although several different exemplary embodiments of dispensing assembly 140 will be illustrated and described, similar reference numerals may be used to refer to similar components and features. Dispensing assembly 140 is generally configured for dispensing liquid water and/or ice. Although an exemplary dispensing assembly 140 is illustrated and described herein, it should be appreciated that variations and modifications may be made to dispensing assembly 140 while remaining within the present subject matter.

Dispensing assembly 140 and its various components may be positioned at least in part within a dispenser recess 142 defined on one of refrigerator doors 128. In this regard, dispenser recess 142 is defined on a front side 112 of refrigerator appliance 100 such that a user may operate dispensing assembly 140 without opening refrigerator door 128. In addition, dispenser recess 142 is positioned at a predetermined elevation convenient for a user to access ice and enabling the user to access ice without the need to bend-over. In the exemplary embodiment, dispenser recess 142 is positioned at a level that approximates the chest level of a user.

Dispensing assembly 140 includes an ice dispenser 144 including a discharging outlet 146 for discharging ice from dispensing assembly 140. An actuating mechanism 148, shown as a paddle, is mounted below discharging outlet 146 for operating ice or water dispenser 144. In alternative exemplary embodiments, any suitable actuating mechanism may be used to operate ice dispenser 144. For example, ice dispenser 144 can include a sensor (such as an ultrasonic sensor) or a button rather than the paddle. Discharging outlet 146 and actuating mechanism 148 are an external part of ice dispenser 144 and are mounted in dispenser recess 142. By contrast, refrigerator door 128 may define an icebox compartment 150 (FIG. 2) housing an icemaker and an ice storage bin (not shown) that are configured to supply ice to dispenser recess 142.

A control panel 152 is provided for controlling the mode of operation. For example, control panel 152 includes one or more selector inputs 154, such as knobs, buttons, touchscreen interfaces, etc., such as a water dispensing button and an ice-dispensing button, for selecting a desired mode of operation such as crushed or non-crushed ice. In addition, inputs 154 may be used to specify a fill volume or method of operating dispensing assembly 140. In this regard, inputs 154 may be in communication with a processing device or controller 156. Signals generated in controller 156 operate refrigerator appliance 100 and dispensing assembly 140 in response to selector inputs 154. Additionally, a display 158, such as an indicator light or a screen, may be provided on control panel 152. Display 158 may be in communication with controller 156, and may display information in response to signals from controller 156.

As used herein, “processing device” or “controller” may refer to one or more microprocessors or semiconductor devices and is not restricted necessarily to a single element. The processing device can be programmed to operate refrigerator appliance 100, dispensing assembly 140 and other components of refrigerator appliance 100. The processing device may include, or be associated with, one or more memory elements (e.g., non-transitory storage media). In some such embodiments, the memory elements include electrically erasable, programmable read only memory (EEPROM). Generally, the memory elements can store information accessible processing device, including instructions that can be executed by processing device. Optionally, the instructions can be software or any set of instructions and/or data that when executed by the processing device, cause the processing device to perform operations.

Referring again briefly to FIG. 1, according to an exemplary embodiment, cabinet 102 also defines a mechanical compartment 170 at or near the bottom 106 of the cabinet 102 for receipt of a hermetically sealed cooling system 172. In general, sealed cooling system 172 is configured for transporting heat from the inside of refrigerator appliance 100 to the outside (e.g., by executing a vapor-compression cycle or another suitable refrigeration cycle). As is generally understood by those of skill in the art, the hermetically sealed system 172 contains a working fluid, e.g., refrigerant, which flows between various heat exchangers of the sealed system 172 where the working fluid changes phases while transferring thermal energy.

In this regard, as understood by one having ordinary skill in the art, sealed system 172 may include a compressor, a condenser, an expansion device, and one or more evaporators (e.g., such as an evaporator 206 described in more detail below) connected in series by a fluid conduit that is charged with a refrigerant. Within sealed system 172, refrigerant flows into the compressor, which operates to increase the pressure of the refrigerant. This compression of the refrigerant raises its temperature, which is lowered by passing the refrigerant through the condenser. Within the condenser, heat exchange with ambient air takes place so as to cool the refrigerant. A condenser fan may be used to pull air across the condenser, so as to provide forced convection for a more rapid and efficient heat exchange between the refrigerant within the condenser and the ambient air. Thus, as will be understood by those skilled in the art, increasing air flow across the condenser can, e.g., increase the efficiency of the condenser by improving cooling of the refrigerant contained therein.

An expansion device (e.g., an electronic expansion valve, capillary tube, or other restriction device) receives refrigerant from the condenser. From the expansion device, the refrigerant enters the evaporator. Upon exiting the expansion device and entering the evaporator, the refrigerant drops in pressure. Due to the pressure drop and/or phase change of the refrigerant, the evaporator is relatively cool. An evaporator fan is typically provided at each the evaporator, e.g., to force air across and around the at least one evaporator to transfer thermal energy from the air to the evaporator (and more particularly, to the working fluid or refrigerant therein).

In this manner, a flow of cooling air exits the evaporator and may be distributed to one or more of the chilled chambers 122 and/or 124. Specifically, one or more ducts may extend between the mechanical compartment 170 and the chilled chambers 122 and/or 124 to provide fluid communication therebetween, e.g., to provide the chilled air from the hermetically sealed cooling system 172, e.g., from an evaporator thereof, to one or more of the chilled chambers 122 and/or 124.

The sealed system 172 described herein is provided by way of example only. Thus, it is within the scope of the present subject matter for other configurations of the refrigeration system to be used as well. For example, according to alternative embodiments, sealed system 172 may include additional components, e.g., at least one additional evaporator, compressor, expansion device, and/or condenser. For example, refrigerator appliance 100 may have two or more split evaporators, e.g., one dedicated primarily to cooling fresh food chamber 122 and one dedicated primarily to cooling freezer chamber 124. In addition, alternative plumbing configurations, valves, and flow regulators may be used to route refrigerant throughout sealed system 172.

In some embodiments, refrigerator appliance 100 also includes one or more sensors that may be used to facilitate improved operation of refrigerator appliance 100, such as described below. For example, in order to obtain temperature measurements within one or more chilled chambers 122, 124 (or regions/zones within chilled chambers 122, 124), refrigerator appliance 100 may include a plurality of temperature sensors (not shown). Controller 156 may be communicatively coupled with the temperature sensors, may receive signals from these temperature sensors that correspond to the temperature of an atmosphere or air within their respective locations, and may implement responsive action, e.g., by directing more or less cooling air toward that region or chamber.

As used herein, “temperature sensor” or the equivalent is intended to refer to any suitable type of temperature measuring system or device positioned at any suitable location for measuring the desired temperature. Thus, for example, the temperature sensors may be any suitable type of temperature sensor, such as a thermistor, a thermocouple, a resistance temperature detector, etc. In addition, the temperature sensors may be positioned at any suitable location and may output a signal, such as a voltage, to a controller that is proportional to and/or indicative of the temperature of the air surrounding the temperature sensors. Although exemplary positioning of temperature sensors is described and illustrated herein, it should be appreciated that refrigerator appliance 100 may include any other suitable number, type, and position of temperature and/or other sensors according to alternative embodiments.

Referring still to FIG. 1, a schematic diagram of an external communication system 180 will be described according to an exemplary embodiment of the present subject matter. In general, external communication system 180 is configured for permitting interaction, data transfer, and other communications between refrigerator appliance 100 and one or more external devices. For example, this communication may be used to provide and receive operating parameters, user instructions or notifications, performance characteristics, user preferences, or any other suitable information for improved performance of refrigerator appliance 100. In addition, it should be appreciated that external communication system 180 may be used to transfer data or other information to improve performance of one or more external devices or appliances and/or improve user interaction with such devices.

For example, external communication system 180 permits controller 156 of refrigerator appliance 100 to communicate with a separate device external to refrigerator appliance 100, referred to generally herein as an external device 182. As described in more detail below, these communications may be facilitated using a wired or wireless connection, such as via a network 184. In general, external device 182 may be any suitable device separate from refrigerator appliance 100 that is configured to provide and/or receive communications, information, data, or commands from a user. In this regard, external device 182 may be, for example, a personal phone, a smartphone, a tablet, a laptop or personal computer, a wearable device, a smart home system, or another mobile or remote device.

In addition, a remote server 186 may be in communication with refrigerator appliance 100 and/or external device 182 through network 184. In this regard, for example, remote server 186 may be a cloud-based server 186, and is thus located at a distant location, such as in a separate state, country, etc. According to an exemplary embodiment, external device 182 may communicate with a remote server 186 over network 184, such as the Internet, to transmit/receive data or information, provide user inputs, receive user notifications or instructions, interact with or control refrigerator appliance 100, etc. In addition, external device 182 and remote server 186 may communicate with refrigerator appliance 100 to communicate similar information.

In general, communication between refrigerator appliance 100, external device 182, remote server 186, and/or other user devices or appliances may be carried using any type of wired or wireless connection and using any suitable type of communication network, non-limiting examples of which are provided below. For example, external device 182 may be in direct or indirect communication with refrigerator appliance 100 through any suitable wired or wireless communication connections or interfaces, such as network 184. For example, network 184 may include one or more of a local area network (LAN), a wide area network (WAN), a personal area network (PAN), the Internet, a cellular network, any other suitable short- or long-range wireless networks, etc. In addition, communications may be transmitted using any suitable communications devices or protocols, such as via Wi-Fi®, Bluetooth®, Zigbee®, wireless radio, laser, infrared, Ethernet type devices and interfaces, etc. In addition, such communication may use a variety of communication protocols (e.g., TCP/IP, HTTP, SMTP, FTP), encodings or formats (e.g., HTML, XML), and/or protection schemes (e.g., VPN, secure HTTP, SSL).

External communication system 180 is described herein according to an exemplary embodiment of the present subject matter. However, it should be appreciated that the exemplary functions and configurations of external communication system 180 provided herein are used only as examples to facilitate description of aspects of the present subject matter. System configurations may vary, other communication devices may be used to communicate directly or indirectly with one or more associated appliances, other communication protocols and steps may be implemented, etc. These variations and modifications are contemplated as within the scope of the present subject matter.

As illustrated in the example embodiments, refrigerator appliance generally includes a plurality of chilled chambers. For example, a first chilled chamber is illustrated herein as fresh food chamber 122 and a second chilled chamber is illustrated herein as freezer chamber 124. In addition, refrigerator appliance 100 includes a temperature management system 200 that is generally configured for independently and accurately regulating the temperature within each chilled chamber. Although an example temperature management system 200 is illustrated below for regulating the temperature in fresh food chamber 122 and freezer chamber 124 of a bottom freezer configuration of refrigerator appliance 100, it should be appreciated that aspects of the present subject matter are equally applicable to any refrigerator appliance having two or more chambers of any configuration. In addition, variations and modifications may be made to temperature management system 200 while remaining within the scope of the present subject matter.

As explained above, refrigerator appliance 100 may include a sealed cooling system 172 that forms part of temperature management system 200 and circulates a flow of refrigerant to facilitate heat transfer. Specifically, sealed cooling system may include a compressor 202 that is generally configured for compressing and circulating refrigerant within the sealed cooling system 172. Sealed cooling system may include a single condenser 204 fluidly coupled to the compressor 202 for discharging heat to the ambient environment and cooling the refrigerant. In addition, sealed system 172 may generally include an evaporator 206 for cooling fresh food chamber 122 and freezer chamber 124, as described in more detail below.

As explained briefly above, conventional sealed systems for refrigerator appliances include dedicated evaporators for each independently chilled chamber or a single evaporator with complex ducting and air flow regulation schemes. By contrast, aspects of the present subject matter are directed to temperature management system 200 including an improved evaporator 206 that facilitates accurate and independent temperature regulation within multiple chambers without requiring entirely separate evaporators, complex flow regulation mechanisms, and other complex devices. Moreover, this temperature regulation system 200 is versatile, easy to manufacture/assembly, and lower cost than conventional systems.

In this regard, evaporator 206 may generally include a first evaporator coil 210 and a second evaporator coil 212 that each have a separate inlet but which are joined before returning to the condenser 204. According to the illustrated embodiment, temperature management system 200 may include an evaporator compartment 220 that is divided into a first evaporator plenum 222 and a second evaporator plenum 224 which are at least partially thermally isolated from each other. In this regard, according to the illustrated embodiment, temperature management system 200 may include a mullion 226 positioned within evaporator compartment 220 to define first evaporator plenum 222 and second evaporator plenum 224. According to example embodiments, mullion 226 may be removable for easy assembly, e.g., facilitating installation of evaporator 206 in evaporator compartment 220 prior to thermally isolating first evaporator plenum 222 and second evaporator plenum 224 with the installation of mullion 226.

As illustrated, first evaporator coil 210 is positioned within first evaporator plenum 222 and second evaporator coil 212 is positioned within second evaporator plenum 224. Mullion 226 may define one or more passageways to permit coils of evaporator 206 to pass therethrough without leaking cool air between first evaporator plenum 222 and second evaporator plenum 224. In addition, temperature management system 200 may include an evaporator cover 230 positioned over first evaporator plenum 222 and second evaporator plenum 224, e.g., to define a front of evaporator compartment 220 and separate evaporator compartment 220 from fresh food chamber 122 and freezer chamber 124.

According to an example embodiment, evaporator cover 230 may define one or more fluid passageways through which a flow of air may be circulated between first evaporator plenum 222 and a first chilled chamber (i.e., fresh food chamber 122) and between second evaporator plenum 224 and a second chilled chamber (i.e., freezer chamber 124). More specifically, evaporator cover 230 may define a first supply duct 232 and a first return duct 234 fluidly coupled to the first evaporator plenum 222. Similarly, evaporator cover 230 may define a second supply duct 236 and a second return duct 238 fluidly coupled to the second evaporator plenum 224. According to example embodiments, one or more louvres, dampers, or other flow regulating features may be positioned within or operably coupled to ducts 232, 234, 236, and 238.

In addition, temperature management system 200 may include one or more fans for circulating a flow of air and to regulate the temperature within fresh food chamber 122 and freezer chamber 124. For example, temperature management system 200 may include a first fan 240 operably coupled to first evaporator plenum 222 for circulating a first flow of air in the first chilled chamber (e.g., the fresh food chamber 122) and a second fan 242 operably coupled to the second evaporator plenum 224 for circulating a second flow of air in the second chilled chamber (i.e., the freezer chamber 124). According to the illustrated embodiment, first fan 240 and second fan 242 are positioned behind evaporator cover 230 along the transverse direction T.

Referring now specifically to FIGS. 4 and 6, evaporator 206 will be described in more detail according to an example embodiment. As illustrated evaporator 206 may include a dedicated inlet for each of first evaporator coil 210 and second evaporator coil 212 and a shared outlet. Specifically, first evaporator coil 210 defines a first evaporator inlet 250 and second evaporator coil 212 defines a second evaporator inlet 252. According to an example embodiment, a first capillary tube 254 may be fluidly coupled to first evaporator inlet 250 and a second capillary tube 256 may be fluidly coupled to second evaporator inlet 252, e.g., for controlling the expansion of refrigerant within sealed system 172.

In addition, as illustrated in FIGS. 4 and 6, evaporator 206 may include a single shared outlet 258, such as a Y-shaped joint fitting, a tee joint, etc. According to example embodiments, the flows of refrigerant passing through first evaporator coil 210 and second evaporator coil 212 may be merged at shared outlet 258, e.g., such that a single flow of refrigerant passes exits evaporator 206 and enters compressor 202. It should be appreciated that any other suitable manner of merging the streams of refrigerant is possible and within the scope of the present subject matter. Although evaporator 206 is illustrated as having two coils for independently regulating temperature within two chambers, it should be appreciated that evaporator may include additional coils for cooling additional chambers.

According to the illustrated embodiment, compressor 202 may compress the refrigerant and pass it into condenser 204 of sealed system 172. Sealed system 172 may further include a three-way valve 270 positioned downstream of condenser 204 for selectively expanding and directing the flow of refrigerant to one or both of the first evaporator coil 210 or the second evaporator coil 212. For example, three-way valve 270 may be designed to divide, direct, or otherwise regulate the flow of refrigerant as needed based on the cooling needs of each respective chamber. In addition, according to an example, embodiment, three-way valve 270 may be configured to selectively expand the refrigerant as needed to facilitate the heat exchange process.

Sealed system 172 may further include a single defrost heater 272 that is operably coupled to evaporator 206 for selectively heating evaporator 206 to facilitate a defrosting process. Notably, a single defrost heater 272 may be capable of defrosting both first evaporator coil 210 and second evaporator coil 212. A drain pan 274 may be positioned below evaporator 206 along vertical direction V for collecting condensate from both first evaporator coil 210 and second evaporator coil 212. Therefore, operating defrost heater 272 may melt collected frost/ice and the condensate may drip under the force of gravity into drain pan 274.

As best illustrated in FIGS. 4 through 7, a drain trough 280 may be positioned between first evaporator coil 210 and second evaporator coil 212 along the vertical direction V, e.g., to provide thermal separation between the coils. In order to facilitate condensate drainage and collection, drain trough 280 may define one or more perforations 282 for passing condensate from first evaporator plenum 222 into second evaporator plenum 224. In addition, according to an example embodiment, drain trough 280 may be sloped to direct condensate toward drain pan 274. For example, drain trough 280 may be sloped to a center outlet along the lateral direction L (FIGS. 4 and 5) or to a side of cabinet 102 (FIGS. 6 and 7). Drain trough 280 may be molded into evaporator cover 230 or positioned within evaporator compartment 220 in any other suitable manner.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.