HK1111321A - Curtain air admission assembly - Google Patents

Description

Air curtain air inlet assembly

CROSS-REFERENCE TO RELATED APPLICATIONS

Priority and benefit of U.S. provisional application No.60/614,954 entitled "air curtain admission assembly" filed on 9/30/2004, which is hereby incorporated by reference in its entirety, is hereby incorporated by reference herein.

Technical Field

The present invention relates generally to air curtain admission assemblies and to refrigerated display merchandisers of the type used in supermarkets, mini-marts, convenience stores and other commercial establishments for displaying and merchandising refrigerated or frozen products for sale. More particularly, the present invention relates to an open refrigerated display merchandiser of the type wherein a multi-layer air barrier is formed to separate the cooler refrigerated air within the display area of the merchandiser from the ambient air exposed outside the merchandiser by passing a plurality of air streams through the open product display area of the merchandiser.

Background

Refrigerated display merchandisers (also commonly referred to as display cases) having an open display area are commonly used in supermarkets, mini-marts, convenience stores and other commercial establishments for displaying and merchandising refrigerated or frozen products for sale. The open nature of such display cases allows consumers to simply access the product display area to select and remove products for purchase without the inconvenience of opening a cabinet door to access the products. Typically, in open-front display cases, at least one single curtain of relatively cool refrigerated air is caused to flow downwardly at a relatively high velocity, thereby forming an invisible air barrier between the product display region and the area of the store in front of the display case. The air curtain not only helps to maintain relatively cool refrigerated air within the product display region of the display case, thereby cooling the display product on the shelf of the display case, but also serves to isolate the product display region from the ambient air within the store to some extent. Ambient air entering the open product display area undesirably results in increased energy consumption by increasing the cooling requirements of the refrigeration system associated with the display case. Further, the ambient air may also cause local temperature increases within the product display area to reach temperatures sufficient to cause undesirable increases in product temperature to temperatures that may adversely affect product quality.

A problem encountered in passing a curtain of refrigerated air downwardly across the open front of the product display region of the display case is the entrainment of ambient air in the stream of refrigerated air forming the air curtain. Turbulence exists at the boundary between the relatively high flow air curtain and the substantially stationary ambient air located in front of the display case. As a result of this turbulence, some ambient air is disadvantageously entrained in the air curtain.

A variety of display cases with air curtains have been developed in the prior art to address this entrainment problem. For example, display cases having two adjacent parallel, but independently generated, curtains of refrigerated air are common in the art. Typically, the outermost air curtain is at a slightly higher temperature than the innermost air curtain, as disclosed, for example, by Maehara in U.S. patent No. 4,633,677, to protect the colder innermost air curtain from the effects of ambient air entrainment.

It is also known in the art to form a third air curtain of relatively high temperature ambient air outwardly of one or both refrigerated air curtains as a means of reducing entrainment of ambient air from the store within the refrigerated air curtains. Abraham, in U.S. patent 4,267,706, Brown, in U.S. patent 3,812,684, and MacMaster et al, in U.S. patent 3,517,526, respectively, disclose forming an ambient air curtain outwardly of an innermost refrigerated air curtain, with the outer ambient air curtain directed downwardly parallel and adjacent to the inner refrigerated air curtain. Beckwith et al in U.S. patent nos. 3,648,482, 3,850,003 and 3,937,033, MacMaster et al in U.S. patent No. 3,827,254 and Roberts in U.S. patent nos. 5,345,778 and 5,357,767 respectively disclose forming an ambient air curtain outwardly of a pair of refrigerated air curtains. The air curtain closest to the product display region of the display case is coolest, while the center air curtain is at a temperature slightly greater than the innermost air curtain, but significantly less than the outermost ambient air curtain. The central curtain of warmer refrigerated air serves to cushion the innermost colder refrigerated air curtain from air intrusion from the outermost ambient air curtain. The outermost curtain of ambient air, either parallel to and adjacent the center curtain of air or slightly inwardly toward the center curtain of air, is directed generally vertically downwardly so as to preclude refrigerated air within the center curtain and the innermost colder refrigerated air curtain from flowing outside the product display region of the display case. The outermost curtain of ambient air desirably flows itself to the store near the floor of the display case so as not to be drawn into the return air inlet through which the refrigerated air curtain is returned to the evaporator compartment.

In conventional practice, an ambient air curtain is formed by drawing ambient air from the store environment into a plenum located in the front of the top wall of the display cabinet of the merchandiser by means of one or more fans. The ambient air is then exhausted from the plenum through a grill (grid) to form an air curtain. The grille is adapted to direct an ambient air curtain along a desired path outwardly of the inner curtain of one or more layers of cooler refrigerated air. Conventionally, the inlet passage to the plenum through which ambient air is drawn forms a relatively short and relatively direct path through the top wall of the display case. One disadvantage of this type of intake assembly is that: the air flow discharged through the grille tends to be non-uniform along the length of the display case. The resulting uneven air curtain reduces the overall efficiency and performance of the air curtain. Thus, while generally effective for significantly reducing the amount of entrainment of ambient air in the recirculated refrigerated air as compared to a single air curtain design, a significant improvement in the overall efficiency of the air curtain can be achieved by providing an improved ambient air intake assembly which ensures a substantially uniform flow distribution in the resulting air curtain along the length of the display case.

Disclosure of Invention

It is an object of the present invention to provide an air curtain admission assembly by which it is ensured that a substantially more uniform flow distribution is produced in the formation of an air curtain across an opening.

It is an object of another aspect of the invention to provide a refrigerated merchandiser having an open product display region and equipped with an air curtain admission assembly by which it is ensured that a substantially more uniform flow distribution is created when forming an air curtain across the open product display region.

The curtain air admission assembly of the present invention includes an air inlet and an air outlet and defines a plenum opening to and extending between the air inlet and the air outlet. A flow baffle is disposed within the plenum to divide the plenum into a first flow passage and a second flow passage, the second flow passage having an inlet interfacing in fluid communication with an outlet of the first flow passage. The first flow passage is in flow communication with an air inlet to the plenum and the second flow passage is in flow communication with an air outlet of the plenum. A blower operatively associated with the air curtain admission assembly directs air from outside the enclosure through the air inlet of the plenum, then through the first flow passage, then through the second flow passage and out the air outlet to flow generally through an opening located externally adjacent the air curtain admission assembly outlet. According to the invention, the flow of air through the plenum substantially reverses direction when flowing from the first flow passage to the second flow passage. A perforated flow baffle may be provided within the plenum at the interface of the outlet of the first flow passage and the inlet of the second flow passage. A perforated flow baffle may be provided in the air outlet of the plenum. Or the perforated flow baffle may be a slotted plate.

In another embodiment of the air curtain admission assembly, a third flow passage is formed in the plenum beneath the forward end of the second flow passage, whereby air flow through the second flow passage turns through an angle of at least 90 degrees when flowing from the second flow passage to the third flow passage. In this embodiment, the third flow passage is in flow communication with an air outlet of the plenum. A second flow baffle having a flow blocking portion may be disposed within the plenum to form a third flow passage to substantially reverse flow direction. The second flow baffle may comprise a perforated member through which the air flow must pass into the third flow passage. In one embodiment, the apertured member is an egg-crate-shaped member defining a plurality of flow channels through which air flow may flow into the third flow passage.

In another aspect of the invention, a refrigerated merchandiser is equipped with an improved air intake assembly. In one embodiment, the refrigerated merchandiser of the present invention includes an improved curtain air admission assembly by which is ensured a generally uniform flow distribution of the ambient air curtain along the length of the open front viewing area of the display case. In a preferred embodiment, the curtain air admission assembly includes a housing having a top wall and a perimeter wall, an air inlet and an air outlet, and defines a plenum opening to and extending between the air inlet and the air outlet. A flow baffle divides the plenum into a first flow passage and a second flow passage having an inlet interfacing in flow communication with an outlet of the first flow passage. The air inlet of the plenum opens into the first flow passage and the air outlet of the plenum is in flow communication with the second flow passage. One or more blowers operatively associated with the air curtain admission assembly direct air from the exterior through the air inlet of the plenum, then through the first flow passage, then through the second flow passage and out the air outlet of the plenum generally downwardly across the open-front viewing area of the product display region. The flow of air through the plenum substantially reverses direction when flowing from the first flow passage to the second flow passage. The reversal of direction serves to distribute the air flow more evenly along the length of the display case.

In yet another aspect of the present invention, a refrigerated merchandiser includes a housing defining a product display region having an opening providing access to the product display region and an air curtain admission assembly operatively associated with the housing. The curtain air admission assembly defines a plenum opening to and extending between the air inlet and the air outlet. A flow baffle is disposed within the plenum to divide the plenum into a first flow passage and a second flow passage. The second flow path has an inlet interfacing in flow communication with an outlet of the first flow path. The first flow passage is in flow communication with an air inlet to the plenum and the second flow passage is in flow communication with an air outlet of the plenum. A blower operatively associated with the air curtain admission assembly directs air from outside the air admission assembly through the air inlet of the plenum, then through the first flow passage, then through the second flow passage and out the air outlet of the plenum generally toward the opening of the product display region to thereby form an air curtain across the opening. The flow of air through the plenum substantially reverses direction when flowing from the first flow passage to the second flow passage. In another embodiment, a refrigerated merchandiser includes an air curtain admission assembly having a third flow passage formed in the plenum below the forward end of the second flow passage. The air flow through the second flow passage turns through an angle of at least 90 degrees when flowing from the second flow passage to the third flow passage. In this embodiment, the third flow passage is in flow communication with an air outlet of the plenum. In another embodiment of the refrigerated merchandiser, the housing of the merchandiser includes a first air outlet and a second air outlet. The first air outlet directs the air flow along a first path generally across the opening of the product display region. The second air outlet is in flow communication with the outlet of the curtain air admission assembly leading to the plenum and directs air exiting the plenum along a second path generally across the opening. The first and second paths may be parallel or divergent.

Drawings

FIG. 1 illustrates a side sectional view of a refrigerated merchandiser equipped with an improved curtain air admission assembly in accordance with the present invention;

FIG. 2 is an enlarged side sectional view of the embodiment of the air curtain admission assembly shown in FIG. 1;

FIG. 3 is a side sectional view taken along line 3-3 of FIG. 2;

FIG. 4 is a side sectional view taken along line 4-4 of FIG. 2; and

fig. 5 is a side sectional view of another alternative embodiment of the air curtain admission assembly of the present invention.

Detailed Description

Referring now to fig. 1, a refrigerated merchandiser 10 includes an outer cabinet 12 and an inner cabinet liner 20 defining an open-front product display region 30 within the confines thereof. The outer cabinet shell includes a bottom panel 13, a rear wall 14 extending upwardly from the rear of the bottom panel 13, a top wall 15 extending forwardly from the rear wall, and a pair of spaced apart side walls 16 extending perpendicularly from the bottom panel 13 to the top wall 15 and forwardly from the rear wall. The interior cabinet liner 20 includes a top panel 28, a rear panel 26, a bottom panel 24, and opposing side panels 23 that combine to define an open-front product display region 30. As in conventional practice, each of the cabinet base 13, rear wall 14, top wall 15 and side walls 16 are insulated to thermally isolate the interior of the cabinet 12, including the product display region 30, from excessive heat transfer therethrough.

Perishable products being sold may be displayed on shelf shelves 18 disposed within the product display region 30 on the upper surface of the bottom panel 24. The product display area 30 has an open front 25 to not only allow consumers to view the products, but also to allow consumers to enter the product display area 30 to select and remove various products 80 they wish to purchase. Depending on the particular case in which the product is being sold and whether the product is a frozen product or a non-frozen product, the product display area 30 is cooled in a conventional manner to the desired product temperature, which is typically between-10F and less than about 40F.

The refrigerated merchandiser 10 further includes a refrigerated compartment 40, as shown in FIG. 1, typically disposed in the portion of the display cabinet 12 between the bottom panel 13 and the bottom panel 24, in which components of the refrigeration system, typically an evaporator 50 and an air mover 60 such as one or more axial flow fans, are housed. However, it should be understood that the particular type of blower used is not relevant to or intended to limit the present invention. The length of the refrigerated merchandiser 10 may vary from as little as 2 feet to 12 feet or more. Alternatively, the refrigerated merchandiser may be formed of a plurality of modules, each equipped with an evaporator 50 and one or more fans 60.

The refrigerant passing through the tubes of the evaporator 50 cools the air passing over the surfaces of the evaporator tubes by the action of the blower 60, as in conventional practice. Typically, the refrigerant is supplied by a remote refrigeration unit located elsewhere in the store. However, it should be understood that: the invention may also be used on stand-alone refrigerated merchandisers that include their own refrigeration unit for providing the refrigerant.

An air circulation passage 32 is formed between the rear wall 14 and the top wall 15 of the outer cabinet 12 and the rear panel 26 and the top panel 28 of the respective inner cabinet liner 20. The blower 60 is used to direct air from the air inlet 42 through the compartment 40 to traverse the evaporator 50 and thence through the passageway 32 to the refrigerated air outlet 34. As previously described, the circulating air has been cooled to a desired temperature as it traverses the evaporator 50. The cooled refrigerated air is directed downwardly from the air outlet 34 through a grille of vanes 35 disposed within the air outlet 34 along a first path 45 toward the air inlet 42 to form an inner air curtain 55 across the open front 25 of the product display region 25. To convert the energy consumed in cooling the refrigerated air, the refrigerated air is recirculated through the air inlet 42 and repeatedly recirculated through the compartment 40 and the duct 32 back to and through the refrigerated product display region 30. Additionally, with the foregoing cooling arrangement, a curtain 55 of cooling air is formed across the open-front product display region 30 from its top to its bottom. To provide further cooled air directly to the product display region 30, as in conventional practice, a plurality of openings 27 may be provided at selected locations on the rear panel 26 through which a portion of the cooler refrigerated air circulating through the channel 32 may pass directly into the product display region 30. This refrigerated air will also be drawn by the blower 60 back into the compartment 40 through the air inlet 42 for recirculation.

In the refrigerated merchandiser 10 illustrated in the figures, the second air outlet 70 is disposed outwardly of the refrigerated air outlet 34 at the top front of the cabinet housing 12. The second air outlet 70 includes a grille of vanes 72 for directing relatively warmer air, such as ambient air, downwardly along a second path 75 that is outside the first path 45 along which the cooled refrigerated air flows. In this manner, a relatively warm outer air curtain 65 is formed outwardly of the relatively cool inner air curtain 55, i.e., at a location further away from the product display region 30. The relatively warm outer air curtain 65 acts as a buffer between the relatively cool inner air curtain 55 and the ambient air in the store. In addition, when the external air curtain 65 reaches the floor area of the display case 12, it flows outwardly into the store rather than into the air inlet 42 at the forward end of the bottom portion of the case. Accordingly, entrainment of heated air into the relatively cool inner air curtain and subsequent passage through the inlet 42 into the compartment 40 is minimized, thereby reducing energy consumption in cooling the recirculated refrigerated air. As in conventional practice, the outer air curtain 65 may be directed along a second path 75 that is generally parallel to the first path 45 along which the inner air curtain 55 is oriented. Alternatively, the outer air curtain 65 may be directed along a second path 75 that diverges outwardly away from the first path 45 along which the inner air curtain 55 is oriented, the divergence angle being in a desired range, such as in the range of about 5 degrees to about 50 degrees disclosed in commonly assigned U.S. Pat. No.6,722,149 to Saroka et al, the disclosure of which is hereby incorporated by reference in its entirety. However, it should be understood that the angular relationship between the first path and the second path is optional and not limiting to the application of the curtain air admission assembly of the present invention.

The curtain air admission assembly 100 of the present invention includes a housing 102 disposed atop the refrigerated merchandiser 10. The housing 102 may preferably be mounted to the top wall 15 of the refrigerated merchandiser 10 with the front portion of the housing 102 extending beyond the front end 17 of the top wall 15 of the refrigerated merchandiser 10. Referring now particularly to fig. 2 and 5, the housing 102 has a top wall 106 and a perimeter wall 108 defining a plenum 110. The embodiment shown in fig. 2 comprises a compact, relatively short plenum, while the embodiment shown in fig. 5 comprises an elongated plenum. The embodiment shown in figure 2 is particularly useful for applications where the top wall 15 of the refrigerated merchandiser 10 must be used as a surface on which workers may occasionally walk. In either embodiment, the housing 102 may be mounted directly to the top wall 15 of the refrigerated merchandiser 10 in a conventional manner, such as by an edge flange extending from the perimeter wall 108 that is adapted to be screwed or otherwise fastened to the refrigerated merchandiser. Alternatively, the housing 102 may further include a floor 104 supporting the perimeter wall 108 adapted to be screwed or otherwise secured to the refrigerated merchandiser. The latter configuration is particularly useful for curtain air admission assemblies provided as discrete units for retrofit applications, and is more likely to be used when the curtain air admission assembly is an integral part of an original equipment refrigerated merchandiser.

In either configuration, a flow baffle 112 is disposed within the plenum 110 to divide the plenum 110 into the first flow passage 105 and the second flow passage 107. The enclosure 102 further includes an air inlet 103 to the plenum 110 through which air from outside the enclosure 102 may enter the plenum 110, and an air outlet 109 to the plenum 110 through which air may be exhausted from the plenum. The first flow passage 105 is in flow communication with the air inlet 103 at its inlet end, while the second flow passage 107 is in flow communication with the air outlet 109 at its outlet end. In addition, the first flow path 105 has an outlet interfacing in fluid communication with an inlet of the second flow path 107.

The blower 80, in operative connection with the air curtain admission assembly 100, directs air from outside the plenum 110 through the air inlet 103 of the plenum, then through the first flow passage 105, then through the second flow passage 107 and out the air outlet 109 of the plenum 110 to be discharged generally downwardly through the second air outlet 70 across the open-front viewing area of the product display region 30. Depending on the overall length of the refrigerated merchandiser 10, one or more axial flow fans may be included in the blower 80, as shown. For example, in a 12 foot length refrigerated merchandiser, four fans may be included in blower 80 positioned at spaced intervals along the length of the refrigerated merchandiser 10. Advantageously, each blower 80 may be a fan mounted in the air inlet 103 to the plenum 110 that is driven by a motor provided in the plenum 110. However, the blower 80 may be located outside of the plenum 110, such as upstream of the air inlet 103 of the passageway that supplies air to the plenum from a remote source. The air inlet 103 to the plenum 110 may be provided in the top wall 106 of the enclosure 102 as shown in the figures, or the air inlet 103 to the plenum 110 may be provided in front of a dividing wall 108, as long as the air inlet 103 opens into the plenum 110.

As shown in fig. 2 and 5, the flow of air through the plenum 110 substantially reverses direction of flow as it flows from the first flow passage 105 to the second flow passage 107. Additionally, a second flow baffle 122 may be disposed in the second flow passage 107 at the front of the plenum 110, thereby forming a third flow passage 111 beneath the front of the second flow passage 107. The second flow baffle 122 further serves to partially block flow from the second flow passage 107 into the third flow passage 111 such that air flowing from the second flow passage into the third flow passage once again substantially reverses flow direction. Each of the aforementioned direction reversals serves to more evenly distribute the curtain airflow along the length of the refrigerated merchandiser 10.

Referring now to fig. 2 and 5, a perforated plate 120 may be provided across the air outlet 109 of the plenum 110. Advantageously, the perforated plate may comprise a slotted plate having a plurality of slotted holes 125 therethrough arranged in rows, for example as shown in FIG. 3. The distribution of air through the apertures 125 in the perforated plate 120 may be selectively controllably adjusted or varied by offsetting the distribution of the apertures over an area of the plate or by restricting flow through selected apertures, such as by a flow blocking plate 122 disposed adjacent the perforated plate 120 as shown in fig. 2, which acts as a flow baffle, thereby restricting the apertures 125 to selected portions of the plate.

Referring now to fig. 2 and 4, an egg-crate member 130 defining a plurality of flow channels 132 may be disposed across an interface between the second flow passageway 107 and the third flow passageway 111. The flow channels 132 in the egg-crate member 130 are used to effect the desired change in flow direction as the air flow flows from the second flow passage 107 into the third flow passage 111. By adjusting the distance that the second flow baffle 122 extends across the interface between the second flow passage 107 and the third flow passage 111, the distribution of air flowing from the second flow passage 107 to the third flow passage 111 through the flow channels 132 may be selectively varied as desired.

Referring now to fig. 5, a perforated plate 136 may be provided at the interface of the first flow path 105 and the second flow path 107 to further achieve even distribution of air flowing therethrough along the length of the refrigerated merchandiser. Advantageously, the perforated plate 136 may comprise a slotted plate having a plurality of slotted holes arranged in rows therethrough, e.g., similar to the plate 120 shown in FIG. 3. Additionally, a perforated member 138 may be provided at the interface of the second flow passage 107 and the third flow passage 111. The perforated member 138 may simply be formed integrally with the second flow baffle 122 as an extension of the second flow baffle 122. Alternatively, the apertured member 138 may comprise a separate slotted plate having a plurality of slotted apertures therethrough arranged in rows, such as a plate similar to the plate 120 shown in FIG. 3, which is provided as an extension of the second flow baffle 122.

It is to be understood that the foregoing description is intended to be illustrative, and not restrictive. Many modifications and variations of this invention are possible in light of the above teachings, and are within the spirit and scope of the invention. Although a curtain air admission assembly has been disclosed in connection with a refrigerated merchandiser in a preferred embodiment, those skilled in the art may recognize other applications for the curtain air admission assembly of the present invention. Accordingly, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described without departing from its spirit and scope.

Claims (30)

1. A refrigerated merchandiser comprising:

a housing defining a product display area having an open-front viewing area;

an air curtain admission assembly operatively associated with the housing, the air curtain admission assembly including a housing having a top wall and a perimeter wall, an air inlet and an air outlet, the housing defining a plenum opening to and extending between the air inlet and the air outlet;

a flow baffle disposed within said plenum and dividing said plenum into a first flow passage and a second flow passage, said second flow passage having an inlet interfacing in flow communication with an outlet of said first flow passage, said first flow passage being in flow communication with an air inlet to said plenum, and said second flow passage being in flow communication with an air outlet of said plenum; and

a blower operatively associated with said air curtain admission assembly and operative to direct air from outside said enclosure through said plenum air inlet, then through said first flow passage, then through said second flow passage and out said plenum air outlet to substantially span the open front viewing area of the product display region, the flow of air through said plenum substantially reversing direction as it flows from said first flow passage to said second flow passage.

2. The refrigerated merchandiser of claim 1, further comprising a perforated flow baffle disposed within the plenum at the interface of the outlet of the first flow passage and the inlet of the second flow passage.

3. A refrigerated merchandiser as recited in claim 2 wherein said perforated flow baffle comprises a slotted plate.

4. The refrigerated merchandiser of claim 1, further comprising a perforated flow baffle disposed in the air outlet of the plenum.

5. Refrigerated merchandiser as recited in claim 4 wherein the perforated flow baffle comprises a slotted plate.

6. The refrigerated merchandiser of claim 1, further comprising a second flow baffle disposed within the plenum and forming a third flow passage in the plenum beneath the front end of the second flow passage, whereby air flow through the second flow passage turns through an angle of at least 90 degrees when flowing from the second flow passage to the third flow passage, the third flow passage being in flow communication with the air outlet of the plenum.

7. A refrigerated merchandiser as recited in claim 6 wherein the second flow baffle comprises a plate having a flow blocking rear portion and a perforated front portion through which air flow may flow into the third flow passage.

8. The refrigerated merchandiser of claim 6, wherein the second flow baffle includes an egg-crate member defining a plurality of flow channels through which air flow may flow into the third flow passage.

9. A refrigerated merchandiser as recited in claim 8 wherein the flow passages in the rear of the egg-holding box-like member are blocked to prevent air flow therethrough.

10. An air curtain admission assembly operatively associated with an opening for forming an air curtain across the opening, said air curtain admission assembly comprising:

a housing having top and perimeter walls, an air inlet and an air outlet, the housing defining a plenum opening to and extending between the air inlet and the air outlet;

a flow baffle disposed within said plenum and dividing said plenum into a first flow passage and a second flow passage, said second flow passage having an inlet interfacing in flow communication with an outlet of said first flow passage, said first flow passage being in flow communication with an air inlet to said plenum, and said second flow passage being in flow communication with an air outlet of said plenum; and

a blower operative to direct air from outside the enclosure through the air inlet of the plenum, then through the first flow passage, then through the second flow passage and out the air outlet of the plenum substantially across the opening, the flow of air through the plenum substantially reversing direction when flowing from the first flow passage to the second flow passage.

11. The curtain air admission assembly of claim 10, further comprising a perforated flow baffle disposed within the plenum at the interface of the outlet of the first flow passage and the inlet of the second flow passage.

12. The air curtain admission assembly of claim 11, wherein the perforated flow baffle comprises a slotted plate.

13. The curtain air admission assembly of claim 10, further comprising a perforated flow baffle disposed in the air outlet of the plenum.

14. The air curtain admission assembly of claim 13 wherein the perforated flow baffle comprises a slotted plate.

15. The air curtain admission assembly of claim 10, further comprising a second flow baffle disposed within the plenum and forming a third flow passage in the plenum beneath the forward end of the second flow passage, whereby air flow through the second flow passage turns through an angle of at least 90 degrees when flowing from the second flow passage to the third flow passage, the third flow passage being in flow communication with the air outlet of the plenum.

16. The air curtain admission assembly of claim 15, wherein the second flow baffle comprises a plate having a flow-blocking rear portion and a perforated front portion through which air flow may flow into the third flow passage.

17. The air curtain admission assembly of claim 15 wherein the second flow baffle comprises an egg-crate-shaped member defining a plurality of flow passages through which air flow may flow into the third flow passage.

18. The air curtain admission assembly of claim 17 wherein the flow passages in the rear of the egg-crate member are blocked to prevent air flow therethrough.

19. The air curtain admission assembly of claim 10, further comprising a second flow baffle disposed within the plenum and forming a third flow passage in the plenum beneath the forward end of the second flow passage, the third flow passage being in flow communication with the second flow passage and the air outlet of the plenum, the flow of air through the plenum substantially reversing direction when flowing from the second flow passage to the first flow passage.

20. A refrigerated merchandiser comprising:

a housing defining a product display area having an opening providing access to the product display area;

an air curtain admission assembly operatively associated with the housing, the air curtain admission assembly defining a plenum opening to and extending between an air inlet and an air outlet;

a flow baffle disposed within said plenum and dividing said plenum into a first flow passage and a second flow passage, said second flow passage having an inlet interfacing in flow communication with an outlet of said first flow passage, said first flow passage being in flow communication with an air inlet to said plenum, and said second flow passage being in flow communication with an air outlet of said plenum; and

a blower operatively associated with said air curtain admission assembly and operative to direct air from outside said enclosure through said air inlet of said plenum, then through said first flow passage, then through said second flow passage and out of said air outlet of said plenum generally across the opening to the product display region, the flow of air through said plenum generally reversing direction as it flows from said first flow passage to said second flow passage.

21. The refrigerated merchandiser of claim 20, further comprising a perforated flow baffle disposed within the plenum at the interface of the outlet of the first flow passage and the inlet of the second flow passage.

22. A refrigerated merchandiser as recited in claim 21 wherein said perforated flow baffle comprises a slotted plate.

23. The refrigerated merchandiser of claim 20, further comprising a perforated flow baffle disposed in the air outlet of the plenum.

24. A refrigerated merchandiser as recited in claim 23 wherein said perforated flow baffle comprises a slotted plate.

25. The refrigerated merchandiser of claim 20, further comprising a second flow baffle disposed within the plenum and forming a third flow passage in the plenum beneath the front end of the second flow passage, whereby air flow through the second flow passage turns through an angle of at least 90 degrees when flowing from the second flow passage to the third flow passage, the third flow passage being in flow communication with the air outlet of the plenum.

26. The refrigerated merchandiser of claim 25, wherein the second flow baffle comprises a plate having a flow blocking rear portion and a perforated front portion through which air flow may flow into the third flow path.

27. The refrigerated merchandiser of claim 25, wherein the second flow baffle includes an egg-crate member defining a plurality of flow channels through which air flow may flow into the third flow passage.

28. A refrigerated merchandiser as recited in claim 27 wherein the flow passages in the rear of the egg-holding box-like member are blocked to prevent air flow therethrough.

29. The refrigerated merchandiser of claim 20, wherein the housing includes a first air outlet that directs the flow of air generally across the opening of the product display region along a first path and a second air outlet that is in flow communication with the outlet of the plenum and that directs the air out of the plenum along a second path generally across the opening.

30. The refrigerated merchandiser of claim 29, wherein the second air outlet directs air exiting the plenum along a second path in diverging relation to the first path generally across the opening.