Abstract:
A cooling apparatus for such things as convenience foods and beverages has a tilted, open faced bed from which persons may select objects. The apparatus is self-contained, and may run from a standard, single phase electrical outlet. It may be carried by two people, and is suitable for mounting either on its own base in a recess in a checkout counter or other similar installation. The open faced be may have a channel depth of section that is relatively deep as compared with to its width, the flow path length, or the depth of the flow released to run along the channel, thereby tending to discourage mixing of the cooled flow with the surrounding ambient environment. The apparatus may include a two piece molded housing that defines the structural skeleton for both the cooling bed and a lodgement for various elements of the cooling system. The bed may include a porous deck, or drain panels, that may tend to encourgare cooled air to drain toward a cooling plenum intake panel. The bed may include a pooling region adjacent to the air intake plenum in which cooler, less buoyant air may collect.

Description:
FIELD OF THE INVENTION  
       [0001]     This invention relates to the field of cooling apparatus for such things as foods and beverages.  
       BACKGROUND OF THE INVENTION  
       [0002]     Commercial coolers for foodstuffs and beverages are well known. However, it may be that it would be desirable to have a cooling apparatus that may be placed next to the cash register in a grocery or convenience store. Further, rather than having a door that may slide or swing open and closed, it may be desirable to have a cooler that, during the hours in which the store is open, may have an open face.  
         [0003]     While this may be desirable, it poses a number of technical challenges. First, the space available on the counter near the cash register may be quite constricted. Second, the cooling apparatus may need to be relatively quiet. These desiderata may tend to suggest that it would be helpful to have a unit that is self-contained, and that may be operated from a standard 120 V, 60 Hz single phase electrical outlet (or, in Europe or other places, 220 V, 50 Hz, single phase), and that a relatively low power unit be employed, both to keep the noise level down, and to reduce the heat rejection to the interior of the store. The combined desired features of an open faced cooler with a low power requirement may tend to be a difficult challenge to meet, since open faced coolers, by their nature, may tend to spill cooled air outside the cooler envelope, and may, conversely, tend to gain warm (and frequently humid) air that may spill in from the surrounding environment. Finally, for a unit of this nature, it may be desirable that the unit be relatively portable, such that it may be carried and installed by one, or at most two, persons of average size and strength.  
       SUMMARY OF THE INVENTION  
       [0004]     In an aspect of the invention, there is a cooling apparatus having a plenum. The plenum has an inlet and an outlet. The outlet is located higher than the inlet, and is offset in a lateral direction therefrom. A heat exchanger is mounted in the plenum between the inlet and the outlet. At least one air moving device is mounted in the plenum in series with the heat exchanger. The air moving device is operable to draw air in at the inlet, and to compel air to pass through the heat exchanger and to exit the plenum at the outlet. An open faced bed is mounted between the outlet of the plenum and the inlet of the plenum. The bed has a pooling zone to which relatively cooler air may drain. The inlet of the plenum is mounted to draw from the pooling zone. The bed has an air drain manifold mounted therein. The drain manifold is located in the bed in a position to facilitate movement of air to the pooling zone.  
         [0005]     In a feature of that aspect of the invention, the cooling apparatus is a self-contained cooling apparatus further including a housing, the open bed being defined within the housing. The housing has an upper portion and a lower portion, and at least one intermediate mounting fitting. The upper portion stands upwardly of the mounting fitting, and the lower portion extends downwardly of the mounting fitting. In another feature, the mounting fitting is a peripheral mounting array. In still another feature, the peripheral mounting array includes at least one shoulder. In an alternate feature, the upper portion has a first peripheral footprint, the lower portion has a second peripheral footprint, at least a portion of the first peripheral footprint extending proud of the first peripheral footprint, and the mounting fitting including at least one shoulder between the upper and lower portions of the housing. In another feature, the cooling apparatus is a self-contained cooling apparatus further including a housing, the open bed being defined within the housing, and the plenum being contained within the housing. A vapour cycle cooling system is mounted within the housing, the heat exchanger being an evaporator of the vapour cycle cooling system; and the cooling apparatus is contained in a volumetric envelope of less than 15,000 cubic inches.  
         [0006]     In another feature, the cooling apparatus is a self-contained cooling apparatus having an upper portion, a lower portion, and a mounting fitting, the mounting fitting being placed between the upper portion and the lower portion, the upper portion having a first height, the lower portion having a second height, and a ratio of the first height to the second height being in the range of 1:5 to 1:3. In another feature of that aspect of the invention, the apparatus has a width and the plenum extends across at least half of the width. In still another feature, the plenum extends across more than 80% of the width. In yet another feature, a portion of the plenum downstream of the heat exchanger has a width, W, and a depth, D, and an aspect ratio of the width to the depth of greater than 8:1. In a more narrow range the aspect ratio is greater than 12:1. In still yet another feature, the plenum has a narrowed region downstream of the heat exchanger, and a wider, deceleration region downstream of the narrowed region adjacent the outlet.  
         [0007]     In another feature of that aspect of the invention, the cooling apparatus includes a resistance array mounted athwart the outlet. In still another feature, the bed has a base wall, and the base wall of the bed also forms a wall of the plenum downstream of the heat exchanger.  
         [0008]     In another feature, the open bed has raised sidewalls extending between the outlet of the plenum and the inlet of the plenum. In a further feature, the bed included an inclined base wall. In a still further feature, the cooling apparatus has a removable cover for enclosing the open bed.  
         [0009]     In another feature of that aspect of the invention, the cooling apparatus has a molded plastic housing, the housing bounding the bed, and defining a lodgement for a vapour cycle cooling system, the heat exchanger being an evaporator of the vapour cycle cooling system, the moulded plastic housing including an insulated wall between the lodgement and the plenum. In still a further feature, the cooling apparatus has a weight of less than 80 lbs., and falling within an envelope less than 30 inches wide, 30 inches high, and 36 inches deep. In still another feature, the apparatus causes a cooling flow to pass through the bed, and the cooling flow has a nominal Reynolds number in the range of 2500 to 10,000. In yet another feature, the plenum and the bed are separated by a bed plate, the bed plate forming a wall of the plenum, and, in operation, downstream of the heat exchanger, the bed plate flow interacting with the bed plate within the plenum has a nominal Nusselt number in the range of 10 to 25.  
         [0010]     These and other aspects and features of the invention may be understood with reference to the detailed descriptions of the invention and the accompanying illustrations as set forth below. 
     
    
     BRIEF DESCRIPTION OF THE FIGURES  
       [0011]     The principles of the invention may better be understood with reference to the accompanying figures provided by way of illustration of an exemplary embodiment, or embodiments, incorporating principles and aspects of the present invention, and in which:  
         [0012]      FIG. 1  shows a front view of an example of cooling apparatus embodying an aspects of the present invention;  
         [0013]      FIG. 2  shows a left hand side view of the cooling apparatus of  FIG. 1 ;  
         [0014]      FIG. 3  shows a right hand side view of the cooling apparatus of  FIG. 1 ;  
         [0015]      FIG. 4  shows a rear view of the cooling apparatus of  FIG. 1 ;  
         [0016]      FIG. 5  shows a top view of the cooling apparatus of  FIG. 1 ;  
         [0017]      FIG. 6  shows a bottom view of the cooling apparatus of  FIG. 1 ;  
         [0018]      FIG. 7  shows a perspective view from above, in front, and to the right of the apparatus of  FIG. 1 ;  
         [0019]      FIG. 8  shows a cross-sectional view of the cooling apparatus of  FIG. 1  taken on the central plane of the apparatus;  
         [0020]      FIG. 9  is a side view of the apparatus of  FIG. 1  with a cover in place;  
         [0021]      FIG. 10  is a top view of the apparatus of  FIG. 1  with a cover in place;  
         [0022]      FIG. 11  shows the apparatus of  FIG. 1  from above and to one side with internal panels removed;  
         [0023]      FIG. 12  shows a bed panel of the apparatus of  FIG. 1 ;  
         [0024]      FIG. 13  shows internal deck panels of the apparatus of  FIG. 1 ;  
         [0025]      FIG. 14  shows rear view of the apparatus of  FIG. 1  with closing panel released;  
         [0026]      FIG. 15   a  shows a manifold panel of the apparatus of  FIG. 1 ; and  
         [0027]      FIG. 15   b  shows an enlarged detail of the manifold panel of  FIG. 15   a.   
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0028]     The description that follows, and the embodiments described therein, are provided by way of illustration of an example, or examples, of particular embodiments of the principles of the present invention. These examples are provided for the purposes of explanation, and not of limitation, of those principles and of the invention. In the description, like parts are marked throughout the specification and the drawings with the same respective reference numerals. The drawings are not necessarily to scale and in some instances proportions may have been exaggerated in order more clearly to depict certain features of the invention.  
         [0029]     In terms of general orientation and directional nomenclature, for the cooling apparatus  20  described herein, the height, in most common use, is measured vertically, and may be measured either from the base of the unit, or from a datum defined by the upper surface of a counter  18 , such as a check-out counter in a grocery or convenience store, or fast food outlet. The width of the unit is a dimension measured generally horizontally across the unit as a person facing the unit might see it. The depth of the unit, or portion thereof, may be the front-to-back distance through the unit. The term “depth” is used in several contexts in this disclosure. In the context of a display bed, the depth may be the normal distance from the base of the display array or bed which, itself, may be angled relative to the horizontal. In the context of a flow plenum, the depth may be the through thickness of the plenum, as contrasted with the length (distance along the plenum) or width or breadth (across the plenum, cross-wise to the flow direction).  
         [0030]     By way of general overview, a cooling apparatus according to an aspect of the present invention is shown in the various Figures as  20 . At a global level, apparatus  20  includes a housing, such as may be termed a housing structure or assembly,  22 , to which a bed plate  24  is mounted to define a heat exchange plenum  26  (below bed plate  24 ), and a bed for objects to be cooled, indicated generally as  28 , and in which a lodgement  30  is defined for various elements of a heat extraction system, such as a vapour cycle cooling system  32 . In operation, cooled goods such as beverages or sandwiches are placed in bed  28 . Cooling system  32  is operated to cool air in plenum  26  running under bed  28 , and to urge that air out through an outlet, or outlet manifold  34  to drift down over the objects to be cooled in the bed. At the lower end of bed  28  there is an air intake  36  for plenum  26 . Inasmuch as bed  28  may have a shape generally resembling a box that has been tilted on an incline, there may tend to be a pooling region  38  next to air intake  36  such that the cooler air may tend to be re-circulated back into the plenum.  
         [0031]     Looking at cooling apparatus  20  in greater detail, the framework structure of the self-contained cooling apparatus  20  is the housing, or housing assembly  22 . Housing assembly  22  may have a two piece moulded construction that may include a first moulded part  40  and a second moulded part  42 , bonded or fastened together after moulding. The two moulded parts,  40 ,  42  may have continuous double walls filled with a foam insulation. Housing assembly  22  may be made of a moulded plastic such as Polyethylene which may be rotationally moulded. The first moulded part  32 , such as may be referred to as the base, may include a front wall portion  44 , a generally upwardly and rearwardly extending wall  46  which may be of irregular form, and left and right hand side wall portions  48  and  50 .  
         [0032]     Front wall portion  44  may have a first, or main portion  52  that is generally rectangular, and that slopes generally upwardly and forwardly of the meeting with wall  46 . The outwardly facing surface of portion  44  may have a decorative pattern formed therein, such as corrugations, or flutes  54 . At the upward end, front wall portion  44  may terminate in a bulbous portion  56  that may have a generally upwardly facing stepped sill  58  for interlocking mating engagement with second molded part  42 . The inner facing portion  40  of front wall portion may have a standoff member  60 , or members, such as may be in the nature of lateral lands  62  and  64 , such as may have the form of an abutment, or shoulder, standing proud of the main inwardly facing surface  66 , and which may be referred to as plenum intake manifold abutments.  
         [0033]     Wall portion  46  may have a first, downwardly facing region  60  that in use may sit in a substantially horizontal orientation, and, in some instances, may provide a base surface  70  upon which the unit (i.e. apparatus  20  generally) may sit. Wall portion  46  may also have a generally upwardly facing surface  72  that may be sloped, and that may run into surface on a smoothly radiused corner. Surface  72  may have a first, or lower, portion  74 , a second, or upper portion  76 , with a convergent transition portion  78  between portions  74  and  76 . Wall portion  44  may also have formed in it, possibly centrally, a relief or port  82  by which an evaporator return line may be installed. Bed plate standoff members, such as may be in the nature of ledges, or shoulders identified as lateral abutments  82  and  84  stand proud of surface  72 , and may provide side rails or seats on which to support laterally extending bed plate  24 .  
         [0034]     Inclined wall portion  46  may also include a downwardly opening relief portion  86  such as may tend to define the inner and upper walls  88 ,  30  of a lodgement, indicated generally as  30 , for accommodating elements of the heat extraction apparatus such as a compressor  92 , condensor  94 , an expansion device, such as may be an adiabatic nozzle  96 , and exhaust fans  98 ,  100 . The upward and rearward edge  102  of inclined wall portion  46  may be formed to mate with a corresponding edge of portion of second molded part  43 . The inner and upper surfaces of lodgement  30  may have a thermally conductive metal liner plate.  
         [0035]     The side wall portions  48  and  50  may include a first portion  106  forming a generally triangular web between front wall portion  44  and inclined wall  46 . First portion  106  may have a generally horizontal upper margin  108 . Sidewall portions  48  and  50  may also include rearward side wall portions  110 ,  112  that bound lodgement  30  laterally. That region of side wall portion  110 ,  112  lying above the height of upper margin  108  may be outwardly relieved to accommodate the mating, downwardly extending sidewall, or skirt, portions  114 ,  116  of second molded part  42 .  
         [0036]     Second molded part  42  may include left and right hand sidewalls,  118 ,  120 , a front framing member  122 , and a rear cowling  124 . Each of side walls  118 ,  120  has a notched region  126  for accommodating a clear plastic side shield  128 , whose upper margin may be roughly tangent to front framing member  122  and rear cowling  124 . Front framing member  122  has a stepped lower surface  130  for mating engagement with the stepped (or keyed, or indexed) upper sill  58  of the bulbous portion  56  of front wall portion  44 ; and a may have a radiused upper surface generally matching the radius of bulbous portion  56 . Sidewalls  118  and  120  are molded to fit outside then wing or skirt portions  114 ,  116  of the sidewalls of lower molded part  40 , such that the externally visible separation line  132  runs horizontally from the front to the back of the unit.  
         [0037]     Rear cowling  124  may include a substantially vertically extending rear wall portion  134 , and a substantially horizontal top wall portion  136 , the two meeting at a smoothly radiused corner, and extending laterally from side-to side between side walls  118 ,  120 . Rear wall portion  134  also has a depending lip  138 . The lower edge of vertical wall portion  134  may be angled inwardly of lip  138  to form a mating notch to seat on with the chamfered nose of the upper edge of inclined wall portion  46  of first molded part  40 . The overlapping interface of molded parts  40  and  42  at back and front, and in large portion along the sides, may tend to yield an assembly that is easily fit together, particularly if the upper molded part  42  is molded for a slight interference fit. It may be noted that the side portions of second molded part  42  may include upper wing extensions  140  having a slot  142  formed therein to receive a roll bar  144  of a removable cover  146 . Cover  146  may be extended to cover bed  28 , at times, for example when the store is closed, cover  146  then discouraging the spilling of cooling air from bed  28 . The bottom edge  148  of cover  146  may have a cross bar  150  whose ends extend to seat in notches  152  in the upper margin of the clear plastic side shields  128 .  
         [0038]     The two plastic moulded parts  40 ,  42  may tend to provide an assembly that may be quickly joined together, with a small number of fasteners and without undue effort. The moulded hard foam plastic may tend to yield an insulated layer (namely the sloped sheet region) between the cooling air plenum, and the lodgement or chamber for the vapour cycle system such as the compressor and condenser, that may reject a significant amount of heat. Lodgement  30  may itself tend to form a hot air heat rejection plenum.  
         [0039]     As assembled, it may be noted that the sidewall portions  48 ,  50  of lower molded part  40 , have laterally extending flanges  160 ,  162 , that may underlie the downwardly depending lower margins of the skirts  114 ,  116  of upper molded part  42 . The underside of flanges  160 ,  162  may form downwardly facing peripheral supports, or mounting fittings, or seats,  164 ,  166 , through which interfaces the weight of the unit may be carried into surrounding structure, as in the case where unit  20  is mounted to sit in a partially sunken manner in an aperture or accommodation made in a store counter. It may also be that the juncture of the radiused bulbous portion  56  of front wall portion  44  may be roughly flush with seats  164 ,  166 , thereby providing a third edge along which underlying structure may support the loaded unit. This may yield a three-sided, generally U-shaped mounting fitting support interface.  
         [0040]     It may be noted that many possible configurations of mounting fitting may be constructed. In the embodiment illustrated, the footprint of the base is smaller than the footprint of the shoulder, such that at least a portion of the footprint of the shoulder extends beyond the footprint of the base, with the result that while the footprint of the base may be lowered through an opening made therefore in a counted, those portions of the footprint of the mounting fitting that protrude beyond the footprint of the base may tend to seat upon, or mate with, the land about the opening formed to admit the base. Although additional fittings, such as brackets, may be mounted to the housing for this purpose, provision of the shoulder in the molded form of the housing itself may tend to eliminate the need for additional separate parts to be made and attached.  
         [0041]     The mounting fitting support interface may be located to permit apparatus  20  to be mounted either on the planar base, generally, or for a substantial portion of apparatus  20  to be mounted in a sunken, or recessed, manner, which may be less obtrusive, and which may require less above counterspace. Taking the height of the base of the unit as h 1  as measured from the substantially planar, horizontal bottom surface to the substantially parallel planar underside of the mounting fitting, and taking the height of the superior portion of the unit as h 2 , with the total oval height of the unit, h total  being the sum of h 1  and h 2 . In one embodiment, the ratio of h 1  to h 2  may be in the range of 1:4 to 1:2, and may be about 2:5.  
         [0042]     The lower portion  168 ,  170  of the outwardly facing surfaces of side wall  118 ,  120 , lying below flanges  164 ,  166  may have a decorative wavy, or fluted, or corrugated pattern  172  formed in relief, and such pattern may be inclined at an angle. The angle may be roughly the same as the angle of inclination of front wall portion  44  more generally.  
         [0043]     Once the upper and lower parts  40 ,  42  of the moulded housing assembly  22  have been fit together and secured, either by mechanical fasteners such as threaded fasteners or by bonding, the remaining fittings may be installed.  
         [0044]     A heat exchanger  174  may be mounted to lower portion  74  of surface  72 . Heat exchanger  174  may extend the full width between shoulder abutments  62  and  64 , and may have a through thickness depth that is, within tolerance, substantially the same as the height of the shoulder abutments  62 ,  64  such that the upper surface of the heat exchanger is roughly flush with the upper surface of the shoulders. The upper-surface of the heat exchanger may have a seal member  174 , such as may be an elastomer, to take up any mismatch in height, and to discourage air flow past the heat exchanger, rather than through it. When overlying plate  24  of the cooler bed  28  is in place, heat exchanger  174  may tend to lie across the entire flow path of the resulting plenum, such that air forced along plenum  26  may tend to be compelled to flow through heat exchanger  174  rather than around it. The upslope bottom corner of heat exchanger  140  may seat in a relatively sharp corner formed at the juncture of transition portion  78  with lower portion  74  of surface  72 .  
         [0045]     Upstream of heat exchanger  174  is a baffle plate  178  that also extends across, and blocks, the flow path of air plenum  26 . Baffle plate  178  has two openings  180 ,  182  formed therein, and location fittings  184 , in the nature of appropriate fastener hole patterns, to which a pair of air moving devices  186 , such as may by blowers or fans  188 ,  190  may be mounted. It may be understood that a single fan could be used, or more than two fans could be used, and that the illustration of two such fans is intended to be representative of any number of such units. It may be that two such units, mounted to work in parallel, may be employed.  
         [0046]     A thermally conductive sheet or plate member, such as plate  24  may seat over shoulders, thus closing, the hollow rectangular passageway to define air cooling plenum  26 . It may be noted that plate member  24  has a first portion  192  for seating on the shoulders namely abutments  82 ,  84  which portion may be planar; and a second, lower or foot portion  194 , that may be bent at a right angle, and that may seat on the shoulders defined by lateral lands  82 ,  84  of front portion  44  of housing assembly  22 . Foot portion  194  may have intake porting, such as may be in the nature of an array of vents or apertures or slots, indicated generically as  196 . The placement of plate  24  in this position may tend to enclose internal air cooling plenum  26 . Plenum  26  may then have an inlet, indicated generally as air intake  36  at array  196 , and an outlet indicated generally as  200  at the upper, laterally offset end of the enclosure. An outlet array  202  may be mounted across outlet  200  between a retaining guide, or channel  204  mounted in the roof portion, and an angle retainer  206  installed along the lower edge of array  202  and secured at either end to shoulders  82 ,  84 . Outlet array  202  may be in the nature of a flow resistance element  208  that may be porous. In one embodiment array  202  may include a large number of tubes, or a honeycomb, or honeycomb-like structure (See enlarged detail of  FIG. 15   b ) that may tend to yield a measure of flow resistance, and that may tend also to cause the flow leaving the plenum to have a relatively flat velocity profile. That is, the velocity of cooled air leaving the plenum may tend to be generally uniform across the outlet array, or more uniform than it might otherwise be.  
         [0047]     The resulting plenum structure may be thought of as having several regions. There is an inlet manifold region, indicated generally as  210 , that may lie between sidewalls  48 ,  50 , the inclined front wall portion  44 , and foot portion  194 ; a high pressure region  212  located between the air movers  186  and heat exchanger  174 , a convergent region  214  immediately downstream of heat exchanger  174 ; a generally rectangular, relatively high aspect ratio region  216  downstream of the convergent section, and an outlet manifold region  218  where the narrowed rectangular region  216  deepens (and in which the flow may tend to decelerate and be impeded by the outlet manifold flow resistance element  208  of an outlet manifold region  218 . As may be appreciated, in operation, the inflow at foot portion  194  may tend to be diffuse. Operation of air movers  186 , may tend to create a low pressure in intake manifold region  210  as compared to external ambient (indicated as P ∞ ) outside the cooling apparatus. This difference in static pressure may tend to cause air to enter, in a relatively even manner through the intake manifold array  196  into the intake manifold region  210 . Air movers  186  may draw in that air, and may urge it, at a raised static pressure, into pressurized region  212 . The resistance of heat exchanger  174  may tend to have at least a modest flow-evening effect. The mean flow velocity through the heat exchanger may not be excessive, given the large cross-sectional area of the heat exchanger element (the full width of the plenum W P , at a depth δ 1  as great as the size of the fan housings). Downstream of heat exchanger  174 , the flow velocity may tend to increase as the plenum section decreases. In one embodiment, the depth of the air flow passage may be reduced by half, and may be reduced by as much as 60% (+/−). The length, L 2  of the narrowed portion may be more than five times the through-thickness depth δ 2 , which may also tend to encourage the flow to settle into a sheet-like profile that is relatively even across the width of the unit. In width, the width of the plenum, W P , which is substantially constant between the inlet manifold and the outlet manifold, extends across more than half the width of the unit, and may, other than for the width of the shoulders, extend across substantially the entire width of housing assembly  22 . In the narrowed, or shallowed, region of the plenum, in one embodiment the Nusselt number based on hydraulic diameter, Nu d  may nominally be in the range of 10 to 25, and may be about 14, without adjustment for non-fully developed flow. In one embodiment, the flow Reynolds number based on hydraulic diameter may be in the range of 3000 to 10 0000. Similarly, in one emobidment the nominal convection heat transfer coefficient, h d , 3 to 15 W/mK, and may be about 5½ to 6 W/mK. In one embodiment, the aspect ratio of width, W P , to depth, δ 2 , of the plenum in the narrowed region  216  may be 8 or greater. In another embodiment, it may be 12 or greater, and in another embodiment it may be about 15 where the depth of the narrowed section may be about 1¼ inches, and the width may be about 19 inches. This may tend to yield a duct having an hydraulic diameter greater than 160% of the through thickness of the passage, with a consequent relatively higher convective heat transfer co-efficient on the underside of the overlying inclined portion  192  of the bed plate  24 . Like the relatively high flow resistance of the heat exchanger, the high aspect ratio of the duct may tend to cause the velocity profile of the flow in the duct to be relatively flat from side to side across the duct. As the flow leaves shallow, or narrowed region  216 , the section of the plenum widens (or deepens, actually, while the width remains constant), which may tend to encourage the flow to decelerate. The momentum of the flow, as it may be, may tend to encourage the flow to attach (i.e., work preferentially along) the curved rear wall  220 . A flow interrupter  222 , such as may be in the nature of an angle  224 , may be mounted to the rear wall  220  of the outlet manifold region  218 . Flow interrupter  222  may tend to force the flow outward from wall  220  into the main body of outlet manifold region  216 . The flow resistance in the outlet manifold, like the resistance of the heat exchanger and the high aspect ratio of the duct, may tend to urge the velocity profile of the exiting flow field to be generally uniform. It may also be noted that the outlet array  202  has roughly the same width as the flow plenum  26 , more generally, but a depth of roughly four to six times the depth of narrow portion of the flow plenum. It may be that the outlet flow field may have a mean flow velocity of the order of 6-18 inches/second. Considering the bed to be a three sided open channel, the overall Reynolds number based on hydraulic diameter may be of the order of 2,500 to 10,000, and may in one embodiment be about 5000.  
         [0048]     Bed  28  may have additional panel member  230 ,  232 , such as may be in the nature of formed channels  234 ,  236 . Channels  234 ,  236  may have legs  238 ,  240  and a web  242 . Panel members  230  and  232  may be mounted with their toes facing downward, such that legs  238 ,  240  may function as stand-off members to hold webs  242  in spaced relationship away from upper portion  142  of the bed plate  24 . This may tend to yield a drain plenum, or plenums  246 ,  248 . The webs  242  of panel members  230  and  232  may have porting in the nature of an array of apertures  250 . The length of panel members  230  and  232  may be slightly shorter in length that the space between foot panel  134  and retainer angle  206 . Morevoever the radius between portion  194  and  192  may tend to prevent the open bottom end of channel members  234 ,  236  from being tightly closed. As may be noted, bed plate  24  may be made of a thermally conductive material, such as may be aluminum or stainless steel, and may tend to be cooled by the output of heat exchanger  174 . Consequently, air tending to drain between channels  234 ,  236  and plate  24  may tend also to be cooled. Further, that air, being relatively cooler and denser than other air, may tend to have a negative buoyancy, and may tend to drain downward toward foot panel  194 . Further still, as that cooled air drains away, it may tend to draw in replacement air, and, as such, may tend to urge the air immediately above to be drawn toward the base plate through apertures  254 , rather then to be forced out into the ambient surroundings. Channels  234 ,  236  may be considered to be air drain manifolds. It may also be noted that apertures  250  may be of a shape, such as square, and a size, to co-operate with the locating feet of zone dividers,  244 , such as may be used in either cross-wise or length-wise orientations to divide rows of bottles, or to space sandwiches or fruits to keep them from impinging on adjacent items.  
         [0049]     As may be noted, bed  28  may have something of the shape of a tilted open front box, in which the desired flow direction is between the outlet manifold  218  of cooling plenum  26  and the inlet manifold  210  of cooling manifold  26 , The maintenance of a relatively stable, predominantly uni-directional flow field between outlet manifold  218  and the inlet manifold  210  may tend to be enhanced by a number of factors.  
         [0050]     First, the proportions and overall size of the apparatus may tend to discourage flow perturbations, and to encourage the flow to remain within a relatively small envelope. The sides of the open flow channel of bed  28  may include superior portions that may include see-through baffles or partitions, such as side shields  128 , such as may be mounted in the upper margins of the side walls of upper moulded part  42 . These baffles, and the sidewalls generally, may tend to channel the flow to run linearly between the outlet manifold and the inlet manifold of plenum  26 . They may also tend to discourage external perturbations from interfering with the desired cooling flow. In addition, the overall depth of the sidewall, indicated as h 3 , may be greater than the depth of the outlet manifold, indicated as h 4 . The ratio of h 3  to h 4  may lie in the range of 6:5 to 5:3, and may be about 9:7 to 4:3. Further, the overall width of the open flow channel is not excessive as compared to its length. That is, the mean length of the flow path from the center of the outlet manifold of plenum  26  to the center of the inlet manifold of plenum  26  is indicated as L 1 . The width is indicated as W. The ratio of depth h 3  to width W may be more than ¼, may be in the range of 1:2 to 1:2, and may be about 2:5. The ratio of the width W to length L may be less than 3:2, may lie in the range of 4:3 to 4:5, and may be about ⅚ to ⅞, (+/−10%). The length of the flow path between the outlet manifold and the inlet manifold may also be relatively short as compared to the depth. The ratio of h 3  to L may be greater than ¼, may lie in the range of than 3/10 to ½, and may, in one embodiment be between ⅓ and ⅜. In one embodiment, W may be about 22 inches, L may be 18½ to 19 inches, h 1  may be about 6½ inches, h 2  may be about 15½ inches, h 3  may be about 6½ to 7 inches and h 4  may be about 8½ to 9 inches, all dimensions being +/−10%. The unit may fall within an overall envelope that is less than 30 inches wide, less than 36 inches deep from back to front, and less than 30 inches tall. The volumetric envelope of the entire apparatus  20  may be less than 15,000 cu. in., and in one embodiment may be less than 11,000 cu. in., and of that, if a sunken installation is used, the exposed volume occupied may fit within an envelope that is less than 30 inches wide, less than 36 inches deep, and less than 24 inches high; and that envelope may have a volume of less than 11,000 cu.in, and in one embodiment, less than 8,500 cu. in. In one embodiment, the unit may weigh less than 80 lbs.  
         [0051]     Second, the use in flow resistance element  208  of parallel capillaries or small diameter tubes, such as may have a length more than 5 times their diameter, may tend to straighten, and calm, the output of cooling plenum  26 . Further, the resistance of those tubes may tend to cause the output across the array to be more even. Third, the lower end of the box may tend to form a pooling zone having a triangular bottom between parallel sidewalls in which the relatively cooler air, being less buoyant, may tend to collect. The upper lip of the pooling region may be the top of front framing member  122 . Fourth, the use of an intake manifold array of porting or apertures, such as slots  212  in foot panel  64  may tend to permit the pooling zone to be drained, and may permit the draining to be distributed across the face of the pooling zone. Fifth, the low, or very low, Reynolds number may point to a flow that is substantially laminar if undisturbed, or that may have a tendency away from being strongly turbulent. Sixth, the use of a perforated return drain along the floor of the bed (namely channels  234 ,  236 ) may tend to draw the cooled air down, toward bed plate  24 , rather than encouraging it to spill outside the box. These features are thought advantageously to increase the proportion of air returned to the intake manifold that may tend to be recirculated cooled air that has already been cooled below the more generally prevailing ambient temperature T ∞ , and may tend to improve the overall efficiency of the unit and tending to reduce the cooling load and so too the power required and the heat rejection to ambient.  
         [0052]     In cooling apparatus  20 , the cooling system may be a vapour cycle system  32 , and heat exchanger  174  may be the evaporator of such a system. The other elements of such a system may include compressor  92  whose intake is from a low pressure return line  256  in fluid connection with the output fitting of heat exchanger  28 . Low pressure return line  256  may by installed through molded port  258  made in inclined wall portion  46 . Insulating putty or sealant may be used to further discourage heat loss or flow migration through port  208 . Compressor  92  may be mounted on a base plate  260 , itself mounted to lower part  40  of moulded housing  22 . The compressed working fluid output from compressor  92  may be led through a high pressure gas line  262  to condensor  94 . Condensor  94  may be mounted to a rear closure panel  264  that forms the closed back panel of the vapour cycle equipment lodgement  30 . Condensor  94  may take the form of a heat exchanger mounted to seat against the peripheral seals  266  of a corresponding opening  268  in back panel  264 . Air moving equipment, such as may be in the nature of a pair of rejected heat exhaust blowers, or fans,  98 ,  100  are mounted to another portion of panel  264 , and, given the otherwise generally sealed nature of lodgement  30 , conservation of mass requires that air drawn in through the heat exchanger fin array of condensor  94  must be purged through fans  98 ,  100 , thus cooling compressor  92  as well. An exhaust shroud, or doghouse, or standoff housing  274  may be mounted about the outlet of fans  98 ,  100  to prevent the unit from being forced too tightly against a rear surface, such as might otherwise prevent fans  98 ,  100  from providing the airflow desired to cool the unit. A cooled high pressure line  274  leads from condenser  94  to a substantially adiabatic expansion device, such as may be in the nature of a nozzle  276 . The cooled, low pressure output of this element is fed through a coolant feed line  278  through insulated inclined panel portion  46  to the downstream side of heat exchanger  174 , bringing the cycle back to its starting point. The unit may be controlled by conventional thermostatic settings on the rear of the unit.  
         [0053]     An optional cover  280  may be employed when the unit is in a passive mode, such as when the store is closed, if the unit is used in a store. The unit is provided with a thermometer  282 . To reduce the height profile of the unit, much of the base can be sunk into a counter top, such that the unit is supported about its periphery on the shoulder  284 , the front portion of the shoulder being defined by the underside of the bulbous portion of the front of the unit.  
         [0054]     Thus, the apparatus described is a mechanically cooled, insulated container that may be used to permit manual dispensing of bottled or canned goods, sandwiches and other fast food items. The container is so configured that a cold air curtain, which tends to isolate the merchandise from the outside temperature, drops at a relatively acute angle such as may tend to allow the merchandise to be displayed in an advantageous, highly visible, and conveniently reachable angle.  
         [0055]     Various embodiments of the invention have been described in detail. Since changes in and or additions to the above-described best mode may be made without departing from the nature, spirit or scope of the invention, the invention is not to be limited to those details but only by the appended claims.