Abstract:
The in-wall chiller may include a housing having a size and shape, including a depth of approximately 3.5 inches and a width of approximately 14.5 inches, conductive for installation in a standard size wall frame. The in-wall chiller may further include one or more cooling modules disposed in the housing, which may include a chilling plate coupled to one side of a Peltier chip and a heat sink coupled to the other side, wherein the relatively low temperature transferred to the chilling plate cools water within the in-wall chiller, which may be stored for an extended duration within an insulated storage tank; the heat extracted from the cooled water being transferred to the heat sink and dissipated out from the in-wall chiller by a fan mounted thereon.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention generally relates to chillers for potable water dispensers. More specifically, the present invention relates to in-wall chillers for potable water dispensers having a size and shape conducive for select installation within the frame of a standard size wall. 
         [0002]    In-wall compressor-based chillers for making cold drinking water are generally known in the art of the drinking water industry. In this respect, a “remote chiller” is one type of compressor-based standalone refrigeration device that includes an internal compressor for cooling water before being delivered to a potable water dispenser, such as a drinking fountain. Such a remote chiller may be used to cool water “instantaneously” as the water flows from a supply line to a drinking fountain. The remote chiller may couple to a drinking fountain or the like by an insulated tube, to ensure cooled water generated by the remote chiller is dispensed from the potable water dispenser at a desired and consistent temperature. Accordingly, the compressor-based remote chiller may be installed in close proximity to the drinking fountain (e.g., underneath or within 12 feet) to minimize the distance the cooled water must travel before being dispensed by the potable water drinking fountain. 
         [0003]    There are a wide variety of compressor-based remote chillers known in the art and made by a number of manufacturers. The problem is that all known compressor-based remote chillers known on the market today are relatively significantly larger than the frame of a standard size wall and certainly do not fit therein. Thus, in most compressor-based remote chiller installations, a frame of a standard size wall is unable to accommodate the compressor-based remote chiller therein because the housing itself is at least 12 inches wide, which is nearly three times wider than the width of the studs in a standard size wall frame. 
         [0004]    This problem is illustrated in more detail in  FIGS. 1 and 2  with respect to two example compressor-based remote chiller installations. For example,  FIG. 1  more specifically illustrates one installation that includes a drinking fountain  10  coupled to and otherwise protruding out from an outer wall  12 . The outer wall  12  mounts to one side of the studs forming the wall frame (not shown as a result of the cross-sectional view) as is known in the art. The outer wall  12  forms a gap  14  with an inner wall  16  attached to the other side of the studs forming the wall frame, as is also known in the art. The diagram shown in  FIG. 1  is representative of a standard wall frame, namely that the outer wall  12  and/or the inner wall  16  may be made from drywall or the like and attach directly to the studs that form the wall frame. The approximate size of the gap  14 , therefore, is dictated by the size of the studs, which are typically at least 2 inches wide by 4 inches deep. Accordingly, the gap  14  is typically approximately about 4 inches. In this respect, the gap  14  may have a shape and size to accommodate at least an internal pipe  18  (e.g., 2 inches in diameter), perhaps among other building features known in the art, e.g., electrical wiring, etc. (not shown). 
         [0005]    But, as shown in  FIG. 1 , the gap  14  does not have a size and/or shape capable of accommodating an in-wall compressor-based remote chiller  20 . While not specifically drawn to scale,  FIG. 1  does illustrate the fact that the in-wall compressor-based remote chiller  20  has an overall width  22  that is substantially larger than the gap  14 . As such, the in-wall compressor-based remote chiller  20  is unable to fit within the gap  14  between the outer wall  12  and the inner wall  16 . Thus, as shown in  FIG. 1 , the in-wall compressor-based remote chiller  20  has been enclosed in a special room  24  sectioned off from the rest of the building interior by a utility wall  26  or the like. The in-wall compressor-based remote chiller  20  may be accessible within the room  24  by way of an HVAC closet or utility room door  28 . 
         [0006]    The in-wall compressor-based remote chiller  20  couples to the vertical internal pipe  18  such as by way of an insulated feed tube  30  extending through the inner wall  16 , to provide cooled potable drinking water to the fountain  10 . Here, the in-wall compressor-based remote chiller  20  may be positioned near or “underneath” the drinking fountain  10 , but the in-wall compressor-based remote chiller  20  still requires a separate room or otherwise needs enough space (i.e., more than just the depth of the gap  14 ) behind the drinking fountain  10  for installation. Close installation proximity of the in-wall compressor-based remote chiller  20  is paramount in quickly delivering a supply of water to the drinking fountain  10  at a desired and consistent temperature. This configuration is obviously undesirable as the location of the in-wall compressor-based remote chiller  20  wastes potentially valuable space inside the building that could be put to other use (e.g., used for office space or the like). Consequently, use of such an in-wall compressor-based remote chiller  20  may undesirably add to the complexity of building designs as special accessible compartments or rooms must be built to accommodate the equipment. Additionally, such known compressor-based remote chillers  20  also increase the difficulty in retrofitting a remote chiller into an existing standard wall as there may not be enough room behind the wall for accommodating such a large unit. Requiring construction of a special wall or empty space behind the wall for installation only adds to the installation cost and complexity. 
         [0007]      FIG. 2  illustrates another installation whereby a compressor-based remote chiller  20 ′ is installed on another floor or within an attic  32 . Here, water may enter the building through a mains water supply  34 , travel through a filter  36  (thereby making the water potable) en route to the in-wall compressor-based remote chiller  20 ′ by way of an input line  38 . The in-wall compressor-based remote chiller  20 ′ then cools the water for delivery to the drinking fountain  10 , for example, by way of a water delivery line  40 . This configuration is different relative to  FIG. 1  with respect to the fact that the in-wall compressor-based remote chiller  20 ′ is installed on a different level of the building than the in-wall compressor-based remote chiller  20 . This may save some space and reduce some building complexities from the standpoint that the in-wall compressor-based remote chiller  20 ′ could be installed in other areas or floors of the building, which may not necessarily require installation immediately behind each water fountain  10 . Although, the configuration shown in  FIG. 2  may require additional insulation for the water delivery line  40  (depending how far the in-wall compressor-based remote chiller  20 ′ is located from the drinking fountain  10 ), additional pumps or other flow control devices, etc. Increasing the distance and the number of components needed to deliver potable water to the drinking fountain  10  only increases the cost and complexity of the installation. For example, if the drinking fountain  10  in  FIG. 2  were added to an existing building and the in-wall compressor-based remote chiller  20 ′ were either already installed or needed to be installed in the attic  32 , the building may need to be retrofitted with additional water lines, such as the input line  38  and/or the delivery line  40  that span multiple floors, all to deliver cooled potable water to the water fountain  10 . 
         [0008]    There exists, therefore, a significant need in the art for an in-wall chiller that utilizes chilling technology (e.g., thermoelectric or miniaturized-compression chilling technology) deployed in a relatively low-profile configuration so the chiller has an overall dimension allowing the in-wall chiller to be installed within a standard wall stud bay (e.g., 14.5 inches wide by either 3.5 inches or 5.5 inches deep). The present invention fulfills these needs and provides further related advantages. 
       SUMMARY OF THE INVENTION 
       [0009]    In one embodiment as disclosed herein, an in-wall chiller may include a housing having a height, a width, and a depth, with at least the width and the depth being of a size and shape for select slide-in reception within a standard building frame. An inlet in the housing may be configured to couple with a water supply so the in-wall chiller may receive a constant (e.g., pressured) water supply. At least one cooling module may be disposed within the housing and fluidly coupled therein to receive water from the water supply at a first temperature. The at least one cooling module may then selectively decrease the temperature of water from the water supply from a first temperature to a second temperature relatively lower than the first temperature. An outlet in the housing may selectively dispense water at approximately the second temperature from the in-wall chiller for consumption, such as by way of one or more drinking fountains coupled thereto. A central shaft within the housing may drain water through an interior of the housing and the standard building frame to a drain, such as unconsumed water dispensed from the drinking fountain. 
         [0010]    More specifically, the at least one cooling module may include a thermoelectric chiller or a miniaturized-compressor chiller having a size and shape relatively smaller than the height, the width, and the depth of the housing. Here, the depth of the housing may be less than approximately 3.5 to 5.5 inches and the width of the housing may be less than approximately 16 to 24 inches. The housing, the inlet, the at least one cooling module, and the outlet may collectively form a standalone retrofit in-wall chiller installable within the standard building frame without relocation of a vertical mounting stud and/or a horizontal mounting stud. In the event the width or the length of the in-wall chiller is less than that of the standard building frame, one or more spacers may selectively couple between an exterior vertical sidewall of the housing and the vertical mounting stud of the standard building frame and/or between an exterior horizontal sidewall of the housing and the horizontal mounting stud of the standard building frame, for flush mounting the in-wall chiller within the standard building frame. 
         [0011]    In another aspect of this embodiment, the at least one cooling module may include multiple cooling modules positioned inline or parallel with one another. More specifically, each of the at least one cooling modules may include a preassembled cooling module that may have a cooling plate, a Peltier chip, and a heat sink having a cooling fan. Here, the Peltier chip may selectively receive direct current for flow therethrough to transfer heat from water at the first temperature adjacent the cooling plate to a side adjacent the heat sink and the cooling fan, thereby cooling water from the first temperature to the second temperature. The cooling fan within the housing may be positioned adjacent a vent in a closure panel of the housing for discharging heat therefrom. 
         [0012]    In another aspect of these embodiments, the in-wall chiller may include a storage tank disposed within the housing and fluidly coupled with water at the first temperature and/or with water at the second temperature. A recirculation pump may also be disposed within the housing and fluidly coupled with the storage tank and the at least one chilling module. The recirculation pump may be generally designed to circulate water at a relatively low flow rate between the storage tank and the at least one cooling module to maintain a desired water temperature therein. In this respect, a controller operationally coupled with the recirculation pump and the at least one cooling module may regulate the speed of the recirculation pump and the electrical energy delivered to the at least one cooling module based on real-time water temperature measurements taken by a temperature sensor and relayed to the controller, for maintaining water within the in-wall chiller at the desired temperature. 
         [0013]    In another embodiment, an in-wall chiller as disclosed herein may include a housing having a height, a width less than approximately 16 to 24 inches, and a depth less than approximately 3.5 to 5.5 inches. Here, at least the width and the depth may be of a size and shape for slide-in reception of the in-wall chiller within a standard building frame. The housing may further include an inlet configured to receive water from a water supply. Multiple cooling modules (e.g., thermoelectric chillers and/or miniaturized-compressor chillers) within the housing may fluidly coupled inline or parallel with one another and selectively decrease the temperature of water within the in-wall chiller from a first temperature to a second temperature relatively lower than the first temperature. The multiple cooling modules may have a size and shape relatively smaller than the height, the width, and the depth of the housing to collectively fit within the housing simultaneously. A storage tank may be disposed within the housing and fluidly couple with water at the first temperature and/or with water at the second temperature. The storage tank may be an insulated storage tank for maintaining water within the in-wall chiller substantially at a desired temperature. An outlet in the housing may then selectively dispense water from the in-wall chiller at approximately the second temperature, such as by way of one or more drinking fountains. 
         [0014]    Each of the multiple cooling modules may include a cooling plate, a Peltier chip, and a heat sink having a cooling fan. The Peltier chip may selectively receive direct current for flow therethrough to transfer heat from water at the first temperature adjacent the cooling plate to the heat sink and the cooling fan. This cools the water from the first temperature to the second temperature while allowing the cooling fan within the housing to discharge heat therefrom by way of a vent in a closure panel adjacent thereto. 
         [0015]    In one embodiment, the housing, the inlet, the multiple cooling modules, and the outlet may include a standalone retrofit in-wall chiller installable within the standard building frame without relocation of a vertical mounting stud and/or a horizontal mounting stud. Moreover, the housing may include a central shaft for draining water through an interior of the housing to a drain, and effectively within the standard building frame when the in-wall chiller is installed. 
         [0016]    The in-wall chiller may also include a controller within the housing that is operationally coupled with a recirculation pump and the multiple cooling modules. Here, the controller may regulate the speed of the recirculation pump and the electrical energy delivered to each of the multiple cooling modules. The recirculation pump may be disposed within the housing and fluidly coupled with the storage tank and at least one of the multiple chilling modules. The recirculation pump may circulate water at a relatively low flow rate from the storage tank through at least one of the multiple cooling modules. The controller may govern cooling by pumping water with the recirculation pump in parallel or inline with one or more of the multiple cooling modules to regulate cooling and energy efficiency in the event one or more of the multiple cooling modules fail. Moreover, the controller may receive real-time water temperature measurements from a temperature sensor also disposed within the housing. This way, the controller can maintain water within the in-wall chiller at a desired temperature. For example, the in-wall chiller may increase the amount of electrical energy delivered to the multiple cooling modules to increase the rate of cooling in the event the water temperature therein is too warm. The controller may also increase the speed of recirculation with the pump to increase the rate of cooling, and vice versa. 
         [0017]    In another embodiment as disclosed herein, a standalone retrofit in-wall chiller may be installable within a standard building frame without relocation of a vertical mounting stud or a horizontal mounting stud. Such an in-wall chiller may include a housing having a height, a width, and a depth, with at least the width (e.g., less than approximately 16 to 24 inches) and the depth (e.g., less than approximately 3.5 to 5.5 inches) being of a size and shape for slide-in reception within the standard building frame. An inlet in the housing may be configured to couple with a mains water supply to receive a quantity of water on-demand. A cooling module may be disposed within the housing and fluidly coupled therein to receive water from the mains water supply at a first temperature. The cooling module may then selectively decrease the temperature of the water from the mains water supply from a first temperature to a second temperature relatively lower than the first temperature. A recirculation pump disposed within the housing may recirculate water at a relatively low flow rate between a water tank and the cooling module. More specifically, a controller operationally coupled with the recirculation pump and the cooling module may regulate the speed of the recirculation pump and the electrical energy delivered to the cooling module for maintaining water within the in-wall chiller at a desired temperature. As such, cooled water may be dispensed out from the in-wall chiller by a dispense outlet in the housing, the dispensed water being at approximately the second temperature. 
         [0018]    In another aspect of this embodiment, the in-wall chiller may include a temperature sensor coupled with the controller for relaying a real-time water temperature within the in-wall chiller to the controller. The cooling module may include a thermoelectric chiller or a miniaturized-compressor chiller having a size and shape relatively smaller than the height, the width, and the depth of the housing. Alternatively, the water tank may include an insulated storage tank having a size and shape to fit within the housing. Here, the storage tank may be fluidly coupled with water at the first temperature and/or with water at the second temperature. 
         [0019]    The cooling module may include multiple cooling modules inline or parallel with one another. In one embodiment, each cooling module may include a cooling plate, a Peltier chip, and a heat sink having a cooling fan. Here, the Peltier chip may be configured to selectively receive direct current for flow therethrough to transfer heat from water at the first temperature adjacent the cooling plate to the heat sink and the cooling fan, thereby cooling water from the first temperature to the second temperature. The cooling fan within the housing may also be positioned adjacent a vent in a closure panel of the housing for discharging heat therefrom. Additionally, a central shaft within the housing may drain water from at least one drinking fountain that selectively receives water at approximately the second temperature from the in-wall chiller, through an interior of the housing and the standard building frame, to a drain. 
         [0020]    Other features and advantages of the present invention will become apparent from the following more detailed description, when taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]    The accompanying drawings illustrate the invention. In such drawings: 
           [0022]      FIG. 1  is a diagrammatic view of a prior art in-wall compressor-based remote chiller installed in a supply room; 
           [0023]      FIG. 2  is a diagrammatic view of the prior art compressor-based remote chiller installed within an attic; 
           [0024]      FIG. 3  is a front perspective view of one embodiment of an in-wall chiller as disclosed herein; 
           [0025]      FIG. 4  is a front view of the in-wall chiller taken about the line  4 - 4  in  FIG. 3 ; 
           [0026]      FIG. 5  is a partial cut-away environmental perspective view of a wall having the in-wall chiller installed within a pair of vertical studs and underneath a drinking fountain; and 
           [0027]      FIG. 6  is a front perspective view of a pair of drinking fountains coupled to an in-wall chiller installed thereunder and coupled to atmosphere by a vent therein. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0028]    As shown in the exemplary drawings for purposes of illustration, one embodiment of an in-wall chiller for portable water dispensers is referenced with respect to numeral  42  in  FIGS. 3-5 . In this respect,  FIGS. 3 and 4  more specifically illustrate the in-wall chiller  42  (e.g., a solid-state thermoelectric chiller or a miniaturized-compressor) in the form of a standalone unit that includes a generally rectangular housing  44  having a height  46 , a width  48 , and a depth  50  conducive for fitting within a standard frame  52  of a building wall  54 , such as shown in  FIG. 5 , to eliminate the need for constructing a special wall or cavity. This may allow for easy installation of the in-wall thermoelectric remote chiller  42  in a wall that may not have been originally designed to accommodate such a chiller. Moreover, it may also reduce the complexity of new building designs as special walls or cavities may not be required. Advantageously, this allows chilled drinking fountains to be installed in locations where it would otherwise not be possible to install a drinking fountain with known compressor-based remote chillers. 
         [0029]    In terms of installation, the in-wall chiller  42  may have the depth  50  sized to accommodate installation into a variety of standard wall frame sizes. For example, in one embodiment, the depth  50  may be approximately 6 inches or less to accommodate installation into a standard wall frame formed by 2-by-6 inch studs. In an alternative embodiment, the depth  50  may be approximately 4 inches or less to accommodate installation into a standard wall frame formed by 2-by-4 inch studs. In either case, the depth  50  of the in-wall chiller  42  should be of a size that is approximately equal to or less than the width of the studs forming the framed wall. This maximizes the size of the housing  44 , while providing enough accommodation to install the housing  44  within the wall  54 . Moreover, the width  48  may be of a size that permits mounting to adjacent studs of the frame  52 . In one embodiment, a distance  56  ( FIG. 5 ) between a pair of generally parallel vertical studs  58 ,  60  may be about 16 inches or 24 inches, depending on the size of the frame  52 . Although, of course, the distance  56  could vary, depending on the desired frame attributes in and around the drinking fountain  10 . Moreover, the width  48  of the in-wall thermoelectric chiller  42  could also vary in size. In either embodiment, the chiller  42  may include one or more spacers (not shown) to facilitate flush mounting between the vertical studs  58 ,  60 . Specifically, in one embodiment, the width  48  of the housing  44  may be 14.5 inches or less. 
         [0030]    Referring back to  FIGS. 3 and 4 , the standalone housing  44  may include an inlet configured for connection of the in-wall chiller  42  to a water supply  62  (e.g., a mains water supply or other building water delivery piping) such as by way of a standard connection to an inlet conduit  64 . The inlet conduit  64  may couple to one of a series of cooling modules  66  that provide cooling to the incoming water as it enters the housing  44  or afterward. In one embodiment, the series of cooling modules  66  may include one or more thermoelectric cooling modules. Alternatively, the series of cooling modules  66  may also include one or more miniaturized compressor cooling modules. To this end, the series of cooling modules  66  may include other devices known for cooling liquid and having a size and shape for mounting within the housing  44 , as disclosed herein. A one-way check valve may regulate the water entering the in-wall chiller  42 , such as in response to dispensing from the drinking fountain  10 . 
         [0031]    In the embodiment shown with respect to  FIGS. 3 and 4 , the in-wall chiller  42  includes three of such cooling modules  66 ,  66 ′,  66 ″. Although, of course, the in-wall chiller  42  may include more or less of the cooling modules  66 , depending on the size (e.g., considering potential in-wall size constraints) and/or desired use (e.g., desired chilling capacity). For example, the in-wall chiller  42  illustrated in  FIG. 5  includes three of the cooling modules  66  to serve the drinking fountain  10 . It may be desired, for example, that the in-wall chiller  42  include six of the cooling modules  66  for service of two drinking fountains, such as the drinking fountains  10  and  10 ′ in  FIG. 6 . In this respect, any number of the cooling modules  66  may be cascaded together to impart lower temperatures to the water therein as needed and/or desired. 
         [0032]    Each of the cooling modules  66  may be a preassembled unit that includes a chilling plate  68 , at least one thermoelectric Peltier chip and a heat sink  70  with a cooling fan  72  positioned thereover. In operation, the cooling modules  66  operate by the Peltier effect, i.e., when direct current (“DC”) electricity flows through the Peltier chip, heat is transferred from one side to the other. In effect, the Peltier chip cools one side of the cooling module  66  adjacent the chilling plate  68  and near the water flow therein while heating the other side adjacent the heat sink  70 . Heat from the heat sink  70  is drawn away from the thermoelectric cooling module  66  during operation by way of the cooling fan  72  to help maintain the “hot” side of the thermoelectric cooling module  66  at ambient temperature while the chilling plate  68  (i.e., the “cool” side of the Peltier chip) goes below ambient temperature to cool the underlying water therein. Each of the cooling fans  72  may be positioned toward the front of the housing  44  and adjacent a vent  74  ( FIG. 6 ) formed in an outwardly accessible closure panel  76  that closes off the interior of the in-wall chiller  42 . The closure panel  74  may screw into the housing  44  and be selectively removable to gain access to the components inside the housing  44  once installed in the frame  52 , such as for repair and/or maintenance. 
         [0033]    While the embodiments disclosed herein utilize Peltier chips to cool water within the in-wall chiller  42 , other types of coolers may be used in accordance with the embodiments disclosed herein. Although, in particular, the Peltier chips include some advantages over vapor-compression refrigeration because Peltier chips have no moving parts, no circulating liquid, relatively long life span, invulnerability to leaks, a particularly relatively small size, and a flexible shape. 
         [0034]    The chilling power of the in-wall chiller  42  as disclosed herein may be relatively less than a traditional compressor-based chiller. In this respect, it may be desired to store water within the in-wall chiller  42  in an insulated storage tank  78 , such as during non-use of the drinking fountain  10 . In essence, the insulated storage tank  78  operates as a thermal energy storage reservoir. The addition of the insulated storage tank  78  allows the in-wall chiller  42  to slowly build up a reservoir of cold water over a relatively long time period, such as during the nighttime when the drinking fountain  10  is typically not in use. In one embodiment, the insulated storage tank  78  may include a large enough capacity to provide chilled water throughout the day, which may permit nighttime refilling. 
         [0035]    A recirculation pump  80  may cycle water from the insulated storage tank  78  through the cooling modules  66  at a relatively low flow rate and at select intervals to maintain the desired water temperature within the insulated storage tank  78 . For example, as shown best in  FIG. 4 , the recirculation pump  80  may draw water in from the insulated storage tank  78  and into the cooling module  66  for further cooling therein. Water then travels from the cooling module  66  to the cooling module  66 ′ by way of an insulated flexible tube  82  therebetween for additional cooling. Water from the cooling module  66 ′ is then displaced to the cooling module  66 ″ by way of an insulated flexible tube  82 ′, for additional cooling. The water in the cooling module  66 ″ is eventually displaced back out to the insulated storage tank  78  to complete the recirculation cycle. In this respect, the water temperature may drop several degrees Fahrenheit with each pass through a respective thermoelectric cooling module  66 . Thus, cascading multiple of the cooling modules  66  in series increases the temperature drop between when the water is pumped out of the insulated storage tank  78  to its return. 
         [0036]    Of course, the in-wall chiller  42  may include any number of cooling modules  66 , recirculation pumps  80 , and/or insulated flexible tubes  82 . For example, for larger installations and/or for installations that utilize multiple of the drinking fountains  10  (e.g., as shown in  FIG. 6 ), one or more of the pumps  80  may be used with one or more cascaded set of the cooling modules  66  to enhance cooling rate and efficiency to ensure the temperature of the water within the insulated storage tank  78  stays consistent. 
         [0037]    A temperature sensor  84  may be coupled to the insulated storage tank  78  to monitor the water temperature therein by way of real-time temperature measurements. Information from the temperature sensor  84  may be relayed to a controller  86 . In this respect, the controller  86  may operate the pump  80  and/or one or more of the cooling modules  66  based on the temperature reading provided by the temperature sensor  84 . For example, the controller  86  may regulate the speed of the pump  84  (including turning it “on” and/or “off” as needed), and may regulate the independent cooling rate of each of the cooling modules  66  (including turning one or more “on” and/or “off” as needed). For example, the controller  86  may decrease the cooling rate by decreasing the amount of energy delivered (e.g., DC) in real-time. Alternative or in addition to, the controller  86  may turn one or more of the cooling modules  66  “off” and/or “on” to regulate the cooling rate of water re-circulated therein. Of course, the controller  86 , each of the cooling modules  66 ,  66 ′  66 ″, the pump  80 , and the temperature sensor  84  may receive energy from a power supply  88  coupled thereto. 
         [0038]    In an alternative embodiment, instead of having the separate recirculation pump  80 , each of the cooling modules  66  may include an integrated recirculation pump  80 . This would allow each of the cooling modules  66  to be plumbed in parallel (as opposed to in series as shown in  FIGS. 3 and 4 ) relative to the insulated storage tank  78  and to provide redundant chilling in case one of the cooling modules  66  fails. 
         [0039]    In another alternative, as shown with respect to  FIG. 5 , the in-wall chiller  42  may include a central shaft  90  that allows water to empty from the drinking fountain  10 , out through a drain  92  therein and into a drain pipe  94  to pass vertically through the in-wall chiller  42  to a building drain  96 . This is a solution to a common problem wherein installers of remote chillers known in the art must reroute such a drain pipe inside the wall (e.g., behind the inner wall  16 ), again requiring special closets or internal rooms to house the equipment. Thus, permitting the drain pipe  94  to couple directly to the central shaft  90  for passage of drain water through the in-wall chiller  42  to the building drain  96  beneficially maintains the in-wall chiller  42 , and related components, within the vertical studs  58 ,  60  of the framed wall  54 . 
         [0040]    Although several embodiments have been described in detail for purposes of illustration, various modifications may be made without departing from the scope and spirit of the invention. Accordingly, the invention is not to be limited, except as by the appended claims.