REFRIGERATORS

Abstract

 A refrigerator is described which comprises a housing defining an interior space to be refrigerated, and adjacent first and second doors mounted at a front of the housing to provide access to the interior space when either or both of the doors are open. The first and second doors define a slit between them at least when both are closed. The refrigerator also comprises an elongate air curtain vent extending across a ceiling of the interior space and arranged to direct a chilled air supply downwards within the interior space to form an air curtain behind the front of the housing, and an air flow diverter arranged to divert a portion of the chilled air supply towards the slit instead of forming part of the air curtain, so as to reduce exchange of air through the slit.

Description

[0001] The present invention relates to refrigerators, such as refrigerated display units or refrigerated display cabinets for use in grocery stores, and for example such refrigerators which have frameless transparent doors.

Introduction

[0002] The electrical energy consumption required to maintain a satisfactory temperature in a refrigerator, typically for chilled or frozen groceries, is significant, particularly for businesses such as grocery store chains which need to run a large number of such units or display cabinets. At the same time, good visibility of, and access to, the groceries or other items stored in the refrigerators is also important. To this end, many such refrigerators do not have doors but instead generate a curtain of chilled air which is downwardly directed within the refrigerator behind the front opening to reduce exchange of air between the chilled interior and warmer exterior.

[0003] Where doors or other closure elements are provided on the refrigerator these will often be largely transparent, and an air curtain may also still be provided in order to reduce air exchange when doors are open, and for other reasons such as reducing misting on the inside door surfaces.

[0004] Frequently, doors with minimal or no frame around a transparent panel are used, which may be referred to as frameless transparent doors. These frameless transparent doors typically provide less opportunity for providing good edge seals with the body of the refrigerator and/or with each other than doors with more substantial frames, but are visibly more appealing and present less of a visual barrier between a shopper and the interior of the refrigerator.

[0005] It would be desirable to address problems of the related prior art.

Summary of the invention

[0006] The inventors have noted that where slits or gaps occur between doors or other closure elements at the front of a refrigerator, the exchange of air between the chilled interior of the refrigerator and the warmer exterior through such slits can be significant. This effect seems to be particularly prominent in refrigerator units in which an air curtain is implemented. However, the inventors have found that directing a flow or jet of chilled air to, towards or along the slit, and in particular in the region of the upper half or upper quarter of the slit, is effective in significantly reducing this air exchange and therefore at increasing the electrical efficiency of the refrigerator in operation.

[0007] The invention therefore provides a refrigerator comprising: a housing defining an interior space to be refrigerated; adjacent first and second doors (or other closure elements) mounted at a front of the housing to provide access to the interior space when either or both of the doors are open, the first and second doors defining a slit between them when both are closed; a chilled air supply vent disposed in an upper half of the interior space and arranged to deliver a chilled air supply into the interior space; and an air flow diverter arranged to receive a portion of the chilled air supply, and to divert the portion of the chilled air supply towards the slit, for example in the form of a jet, so as to reduce exchange of air through the slit when both of the doors are closed.

[0008] The air flow diverted may redirect the received portion of the chilled air supply towards the slit within the interior space to be refrigerated, so typically forwards and/or downwards. However, in some arrangements the air flow diverted may redirect the received portion of the chilled air supply to a position outside the housing, typically above the slit, and direct the chilled air downwards in front of the slit externally to the interior space.

[0009] The adjacent first and second doors may be hinged, for example being hinged to the front of the housing. Each of the doors will then have a hinged edge where the door is hinged to the housing, and an opposite, free edge which is spaced from the hinged edge, the slit may in particular be between the free edges of the adjacent first and second doors, where relative movement of the edges is greatest. However, the invention also applies to a slit formed between a hinged edge of one door and a free edge of another, or between the hinged edges of the two doors.

[0010] The doors (or other closure elements) may in particular be frameless transparent doors, but may be other closure elements such as sliding panels, blinds and so forth. The slit or elongate gap may be defined along substantially the full vertical length between the adjacent first and second doors (or other closure elements).

[0011] The chilled air supply vent may be disposed in various positions within the housing and interior space, for example on a back wall of the housing in which case the air flow diverter may be arranged to channel the portion of the chilled air supply forwards from the back wall of the housing and to release the portion of the chilled air supply proximally to the slit. However, in many arrangements the chilled air supply vent may be an air curtain vent, for example an elongate air curtain supply vent extending across a ceiling of the interior space, and typically supplied with the chilled air supply via a roof duct located above the interior space.

[0012] The invention may then more particularly provide a refrigerator comprising: a housing defining an interior space to be refrigerated; adjacent first and second doors, such as frameless transparent doors, or other closure elements, mounted at a front of the housing to provide access to the interior space when either or both doors are open, the first and second doors defining a slit or elongate gap between them at least when both are closed; an elongate air curtain vent extending across a ceiling of the interior space and arranged to a direct chilled air supply downwards within the interior space to form an air curtain behind the doors (when closed) or behind the front of the housing; and an air flow diverter arranged to divert a portion of the chilled air supply towards the slit, for example in the form of a jet, instead of that portion forming part of the downwardly directed air curtain.

[0013] As noted above, this diverted portion of air reduces exchange of air through the slit, and in particular when both of the doors are closed, thereby increasing the efficiency of the refrigerator in terms of power required to maintain a required temperature.

[0014] In many embodiments the air flow diverter is arranged to divert the portion of the chilled air supply forwards, within the interior space, towards the slit, to achieve the desired effect. For such interior flows, various different geometries of the diverted chilled air flow or jet have been found to be effective in providing the above effect, for example the air flow diverter may direct the diverted portion of the chilled air supply towards the slit at an elevation angle α, or at a range of elevation angles α, where -90° <= α <= 0°, or -70°<= α <= 0°, or -70° <= α <= -20°, or α > -90° , or α > -70°, where 0° is horizontal and negative elevations are downwards. Diverting the portion of the chilled air supply towards the slit may also or instead comprise the air flow diverter releasing the portion of the chilled air supply at a location closer to the slit than the air curtain vent, or at a location closer to the slit than where the air flow diverter received the portion of the chilled air supply.

[0015] Typically, the air curtain vent may comprise an elongate grill extending across a width of the ceiling of the interior space, through which the chilled air supply is delivered into the interior space to form the air curtain. The grill comprises a plurality of passages for directing the part of the chilled air supply passing through the grill. The grill passages may be arranged in hexagonal, rectilinear, or other grid form.

[0016] The air flow diverter may comprise a diverter duct arranged to receive the portion of the chilled air supply and to divert the received portion of the chilled air supply towards the slit as noted above. In some arrangements, the diverter duct may be positioned below the grill and arranged to receive the portion of the chilled air supply from, or after it has passed through, the grill, and these arrangements may be particularly useful in retrofitting already deployed refrigerators to take advantage of the invention. However, in other arrangements the diverter duct may pass through an aperture in the grill.

[0017] In some other arrangements the diverter duct may be positioned or mounted behind the grill, i.e. rearwards from the grill relative to the front of the housing, for example being mounted within the ceiling of the interior space so as to receive the portion of the chilled air supply before the chilled air supply arrives at the grill, for example directly from a roof duct carrying the chilled air supply to the air curtain vent.

[0018] In some other arrangements, the air flow diverter may comprise an oblique deflector which descends underneath the grill towards the slit, or the air flow diverter may comprise a plurality of the passages of the grill which are oriented towards the slit so as to direct the portion of the chilled air supply in that direction.

[0019] In some other arrangements the portion of the chilled air supply may be diverted (before reaching any air curtain vent or other interior chilled air supply vent) through the housing generally above the doors to an external position for direction downwards to and/or in front of the slit externally instead of through the interior space. For example, the air flow diverter may comprise a diverter duct arranged to receive the portion of the chilled air supply before it has passed through the air curtain vent, and to channel the diverted portion of the chilled air supply to an exit aperture of the air flow diverter located in the housing above the slit. The exit aperture is then arranged to direct the diverted portion of the chilled air supply downwards in front of the slit, externally to the first and second doors. In this way, any external air drawn in through an upper portion of the slit will already have been cooled through being at least partly formed by or mixed with the diverted portion of the chilled air supply.

[0020] Whether directing the diverted portion of the chilled airflow towards the slit internally or externally, the air flow diverter may extend at least across the full width of the slit, or across the full width of an upward projection of the slit, in front elevational view of the refrigerator. However, especially for internal arrangements a limited lateral extent of the air flow diverter may be advantageous in reducing the effect on the air curtain, while sufficient lateral extent is needed to provide the jet of diverted air in an effective form. For example, the air flow diverter may extend laterally for one or more of: no more than 10 cm; and more than 1 cm, i.e. along the elongate length of the air curtain vent. Similarly, in order to divert a suitable or optimal volume of chilled air towards the slit, the portion of the chilled air supply diverted by the air flow diverter towards the slit may comprise between 1% and 10% of the total chilled air supply.

[0021] In some arrangements, the air flow diverter may comprise an entrance aperture arranged to collect the portion of the chilled air supply for subsequent direction towards the slit by an exit aperture or nozzle. In order to enhance velocity and/or effectiveness of the diverted air, the lateral extent or the cross-sectional area of the entrance aperture may be greater than the lateral extent or cross sectional area of the exit aperture, such that the flow of chilled air within the air flow diverter is narrowed in a lateral direction. For example, the lateral extent or the cross-sectional area of the exit aperture may be less than 80% of the lateral extent or cross sectional area of the exit aperture.

[0022] The invention also provides various further methods corresponding to or related to the above apparatus and methods, for example a method of operating a refrigerator which comprises a housing defining an interior space to be refrigerated, and at least adjacent first and second doors mounted at a front of the housing to provide access to the interior space when either or both doors are opened, the first and second doors defining a slit between them (at least when both are closed), the method comprising directing a jet of chilled air, within or externally to the interior space, to, towards, or along the slit so as to reduce exchange of air through the slit between an environment within which the refrigerator is housed and the interior space of the refrigerator.

[0023] The jet may for example be directed to, towards, or along the slit in the upper half, or in the upper quarter, of the slit.

[0024] The method may further comprise forming an air curtain within the interior space behind the front of the housing using a chilled air supply, wherein directing the jet of chilled air to, towards or along the slit comprises diverting a portion of the chilled air supply to form the jet instead of the portion of the chilled air supply being used to form the air curtain.

[0025] Alternatively, the interior space may be cooled using a chilled air supply delivered at least in part via a chilled air supply vent, for example such a vent disposed in a back wall of the housing, and the air flow diverter may then be arranged to channel the portion of the chilled air supply forwards for example from the back wall of the housing and to form the jet of chilled air proximally to the slit, for example within about one of 5, 10 or 20 cm from the slit.

[0026] As mentioned above, the first and second doors may be frameless transparent doors of the refrigerator.

[0027] The invention also provides methods of adapting an existing, or an already installed or deployed, refrigerator to reduce energy consumption, using apparatus or methods as described above. For example, the refrigerator may comprise first and second doors having a slit therebetween (and in particular when both are closed), and an air curtain vent located behind the doors to form an air curtain of chilled air, the method comprising installing an air flow diverter at the air curtain vent to redirect a portion of the chilled air towards the slit so as to reduce exchange of air through the slit between an environment within which the refrigerator is housed and the interior space of the refrigerator.

Brief description of the drawings

[0028] Embodiments of the invention will now be described, by way of example only, and with reference to the drawings, of which:

Figure 1 illustrates in perspective view a refrigerator according to the invention;

Figure 2 shows in cross section an upper portion of the refrigerator of figure 1;

Figure 3 shows in plan view an air flow diverter of figures 1 or 2 in context of an air curtain vent formed using a supply of chilled air, and a slit between two doors;

Figures 4a to 4e show in cross section some different ways of implementing the air flow diverter of figures 1 to 3;

Figure 5 shows one way in which the air flow diverter may be implemented to direct a portion of the chilled air supply externally towards the slit;

Figure 6 illustrates a way of implementing the invention without use of an air curtain vent; and

Figure 7 shows a cut through perspective view of a the top portion of the refrigerator with a particular example of the air flow diverter.

Detailed description of embodiments

[0029] Referring first to figure 1 there is shown a refrigerator 10 comprising a housing 12 which defines an interior space 14 to be refrigerated. The housing has an open front 16 which provides access to the interior space. The refrigerator may particularly be a refrigerated display unit in a shop or store such as a grocery store, intended for the storage of food and/or beverage products typically on a plurality of shelves located within the interior space 14. To this end the refrigerator will typically comprise chiller apparatus (not shown in the figure) arranged to maintain the interior space 14 and the products stored therein at a lower temperature than the environment within which the refrigerator is located, for example at around 5° Celsius for chilled groceries, or around minus 18° Celsius for frozen groceries. The chiller apparatus may comprise one or more different components located within and/or exterior to the housing.

[0030] The housing 12 has an open front 16 so that products can be placed into and removed from the refrigerator. However, in order to maintain the lower temperature within the interior space more efficiently, the refrigerator also comprises a plurality of doors typically supported on hinges 20, although other closure elements could be used such as sliding doors, shutters, or blinds. Blinds could for example be intended for use when a grocery store is closed, for example at nighttime, and might typically be implemented as roller blinds which roll open in an upwards or downwards direction.

[0031] Each of the doors (or other closure elements) is disposed across a part of the open front 16 of the housing 12 when closed so as to reduce or substantially prevent mixing between the cooler air within the interior space and warmer air without, but is openable to provide access to the interior space, for example to remove groceries for purchase or to restock with fresh groceries. In the arrangement of figure 1 the open front is largely filled or covered by three hinged doors, the left side door being shown in an open configuration and the centre and right side doors being shown in a closed configuration, but more or fewer doors may be used.

[0032] The refrigerator incorporates air chilling equipment which can be used in various ways to maintain or help to maintain the internal temperature by delivering a chilled air supply. In some embodiments the chilled air supply may be delivered into the interior space via a chilled air supply vent, which may be located in various places, for example in an upper portion of the back wall of the housing. However, in many embodiments the chilled air supply vent may be an air curtain vent arranged to form an air curtain behind the doors and behind the front of the refrigerator.

[0033] In the arrangement of figure 1 the refrigerator 10 is arranged to implement such an air curtain 22 within the interior space, behind the open front of the housing 12, typically by providing a chilled air supply vent in the form of an elongate air curtain vent 24 or egress disposed in an upper part of the interior space 14, for example extending across a ceiling 15 of the interior space 14. This air curtain vent 24 is arranged to direct chilled air downwards within the interior space to form the air curtain 22 behind the front of the housing. A corresponding air intake 26 will then typically also be implemented in a lower part of the interior space for example extending across a floor of the housing, so that the air curtain 22 falls substantially vertically behind most or all of the open front 16, but in front of any shelves (not shown in figure 1) or other storage structures which may be installed within the interior space 14. The chilled air for forming the air curtain is typically delivered to the air curtain vent 14 via a roof duct 17 located above the ceiling 15 of the interior space 14.

[0034] Even though the doors 18 are disposed across the front of the housing and are in front of the air curtain 22 when closed, the air curtain 22 still has significant benefits, for example to reduce exchange of air between the interior space 14 and the outside of the refrigerator at times when one or more of the doors are open. If the doors are transparent or have transparent regions so as to permit viewing of the interior space when closed then the air curtain 22 may serve to reduce misting of inside faces of the doors 18 through separation of those inside faces from the bulk of the chilled air within the interior space.

[0035] It is often desirable to enable customers to see easily into the interior space 14 for inspection and selection of products stored therein, and to this end each door may be transparent, at least over a majority such as at least 80% of the major plane of the door, for example comprising a transparent window fixed securely within an outer frame structure. To maximise the ability of customers to see into the interior space with minimum interference, the doors may in particular be constructed as frameless transparent or glass doors, where the transparent fabric of each door such as a glass sheet or double glazed glass unit extends substantially to one or more, or more frequently to all of the edges of the door, for example with the door being transparent over at least 90% or over at least 95% of the major plane of the door.

[0036] Although the doors, when all are closed, will typically fill or cover substantially all of the open front of the housing 12, some gaps may remain, for example over up to a few percent of the total area of the open front. In particular, such gaps may take the form of one or more slits 28 along the margin between a pair of first and second ones of the doors. Such slits may typically run vertically between pairs of such doors, and may typically run vertically over the full vertical length of the adjacent doors.

[0037] Such slits 28 may particularly arise when frameless transparent doors are used. Using frameless doors tends to reduce the opportunity to add effective and robust seals or baffles at the edges of the doors, especially along the shared margin between two adjacent doors where relative movement occurs. This margin could be at the hinged edges of both adjacent doors even thought the relative movement between the edges will be small, at the free edges of both doors distal from their hinged edges where relative movement is large, or at the hinged edge of one and the free edge of the other. If such seals or baffles are added to frameless transparent doors, there is a tendency for relative movement to lead to such seals or baffles to become broken or detached, at least partly because of the lack of any substantial frame to which they can be fixed securely. Moreover, adding such seals or baffles to frameless transparent doors is likely to reduce desired effects of using such doors such as to maximise the visibility of the interior space to customers and to provide a neat and tidy appearance with the doors themselves being of minimal visual impact.

[0038] Such slits 28 may also arise when other types of closure elements are used instead of doors. For example, if blinds are used to close the open front of the housing 12, such slits may readily arise between adjacent pairs of such blinds. However they arise, the slits may for example be between about 0.2 and 2.0 cm in width, and may typically be at least 100 cm in length or run substantially the full vertical length between adjacent first and second doors or other closure elements.

[0039] Through realistic physical testing and computer modelling the inventors have found that unexpectedly high levels of exchange of air between the cooled interior space 14 and the warmer external environment tend to pass through the above described slits, and that this is especially the case when an air curtain is implemented within the interior space as discussed above. Without wishing to be bound by any particular theory or detailed understanding of the air flow regime, it would appear that movement of the air curtain 22 within the interior space 14 behind such a slit 28 tends to draw warmer outside air in through an upper region of the slit, and to expel cooler inside air through a lower region of the slit.

[0040] However, the inventors have also found that by directing a flow or jet of chilled air, which would otherwise form part of the air curtain, within the interior space towards or along the slit, and in particular towards or along an upper region of the slit, this exchange of air through the slit is significantly reduced, with savings in electrical power required to maintain the interior space at a suitable chilled temperature being found to be of the order of 15-30%. A similar effect is found by directing a flow or jet of chilled air, which would otherwise form part of the air curtain, externally towards or along an upper region of the slit.

[0041] This effect can be achieved by using one or more air flow diverters 30, each arranged to divert a portion of the chilled air supply used to supply the air curtain vent or some other chilled air supply vent towards a slit between a pair of doors, for example as a jet of diverted chilled air, instead of that portion forming part of the main air curtain 22 or some other chilled air circulation pattern within the interior. Two such air flow diverters are depicted in figure 1, each positioned at, or proximally to, the elongate air curtain vent and approximately behind the upper region of a slit defined by two adjacent doors 18.

[0042] Figure 2 illustrates an upper portion of the arrangement of figure 1 in cross sectional view, additionally showing a number of shelves 32 on which products such as groceries may be stored. One of the air flow diverters 30 is shown positioned at or proximal to the curtain vent 24 and arranged to divert a portion 34 of the chilled air which would otherwise form part of the air curtain 22 towards an upper region of the nearby slit 28, so as to reduce exchange of air through the slit when both of the doors defining the slit are in the closed configuration.

[0043] Note that, although not shown in figure 2, air guides for assisting in directing and stabilizing the air curtain may be provided between the ends of some or all of the shelves 32 and the doors 18. These may conveniently be mounted to the ends of the shelves using suitable brackets, and may take the form of aerofoils in which the suction surface of each aerofoil faces the doors 18 and the pressure surface faces the shelves. Such aerofoils are described for example in WO2014/167320, WO2017/089812, and WO2018/162093, the contents of which are incorporated herein in their entirety for these and all other purposes.

[0044] The air flow diverter 30 may divert a portion 34 of the chilled air supply S in a variety of ways to achieve the desired effect of reducing air exchange through the slit, including by changing the direction of that portion 34 of the air flow and/or by laterally displacing that portion 34 of the air flow. For example, whereas the air curtain vent 24 typically directs the air curtain 22 in a downwards direction which is vertical or close to vertical, the air flow diverter 30 may divert the portion 34 of the chilled air supply towards the slit 28 at an elevation angle α, or at a range of elevation angles α as illustrated in figure 2. For example the range of elevation angles may be from vertically downwards (α = -90°) to horizonal (α = 0°), that is -90° <= α <= 0°, or in a range -70°<= α <= 0°, or in a range of -70° <= α <= - 20°, or in a direction which is not vertically downwards so that α > -90° or α > -70°.

[0045] The diverted air flow portion 34 may also or instead be directed towards the slit 28 by the air flow diverter 30 simultaneously over a narrow range of elevation angles α, for example over a range of less than 10° in elevation, or simultaneously over a wider range of elevation angles α for example over a range of 20° or more in elevation angle. The simultaneous range of elevation angles can readily be controlled by suitable construction of an outlet of the air flow diverter 30, and/or by including in the air flow diverter 30 one or more exit vanes 36 arranged to direct the exiting air flow into a particular range of elevational angles.

[0046] An additional or alternative way in which the air flow diverter 30 may divert a portion 34 of the chilled air supply to achieve the desired effect of reducing air exchange through the slit 28 is to displace the diverted portion of the chilled air laterally to a position closer to the slit than the curtain vent, for example by releasing the portion 34 of chilled air with a centre of the released flow which is closer to the slit 30 than the centre or edge of the air curtain, or centre or edge of the air curtain vent. In figure 2 this distance is depicted as horizontal distance d and this distance may for example be at least 5 cm or at least 10 cm. The laterally displaced portion 34 may then be released by the air flow diverter 30 at various angles as already discussed above. The air flow diverter may release the diverted portion of the chilled air supply in the direction of the slit at a variety of distances (shown as distance c) from the slit, but typically reasonably close to the slit, for example no more than one of 5cm, 10cm or 20 cm from the slit, with this distance being measured horizontally as shown in figure 2, or in the direction of the diverted and released air flow.

[0047] Figure 3 depicts the air flow diverter 30 of figure 2 in plan view within the context of the elongate air curtain vent 24 and a slit 28 between nearby adjacent doors 18. In order to divert the portion 34 of chilled air from the air curtain vent 24 towards the slit 30 to reduce exchange of air through the slit, the air flow diverter 30, or more particularly an exit aperture 38 or nozzle of the air flow diverter 30 from which the diverted portion of the chilled air is released, may be located directly behind the slit, or if the top of the slit is lower than the air flow diverter 30 or exit aperture 38 then located directly behind an upward projection of the slit. This relationship can be understood in terms of a front elevational view of the refrigerator (from viewpoint A as shown in figure 2), in which the slit 28 or an upward projection of the slit 28 is in front of at least a portion of the air flow diverter 30 such as the exit aperture 38. Note that the air flow diverter 30 or more particularly the exit aperture 38 may or may not be centred laterally in front of the slit as it is in figure 3.

[0048] The air flow diverter 30, or more particularly the exit aperture 38, may also extend laterally (across the front elevational view of the refrigerator) by a distance consistent with diverting the portion of air to reduce exchange of air through the slit but without seriously compromising performance of the main air curtain itself. To this end, the lateral extent of the air flow diverter 30 or more particularly the exit aperture 38 may be no more than 20cm, or no more than 10 cm, or no more than 5 cm. However, to provide diversion of enough of the air the lateral extent may be at least 1 cm or at least 5 cm.

[0049] In order to provide a sufficiently large effect to reduce exchange of air through the slit but without seriously compromising performance of the main air curtain itself, the volume of the chilled air which each air flow diverter is arranged to divert towards the slit may be from about 1% to about 10% of the total chilled air supply.

[0050] The air flow diverter may also comprise an entrance aperture 40 arranged to collect the portion of the chilled air from the chilled air supply for subsequent diversion towards the slit by the exit aperture 38. For example, if the air flow diverter 30 is implemented as a diverter duct below or within a grill 42 of the air curtain vent then the entrance aperture 40 of the air flow diverter 30 may be located above, within or below the grill 42. In order to divert an appropriate volume of the chilled air from the air curtain towards the slit, the entrance aperture may have an area of between about 1% and 10% of the area of the grill 40, for example in a range of from 20 to 200 cm².

[0051] It will be seen that in figure 3 the lateral extent e, of the exit aperture 38 is smaller than the lateral extent f of the entrance aperture 40. This leads to a narrowing of the air flow within the air flow diverter which may be used for example to assist in focussing and directing the diverted air flow more effectively towards the slit, for example by increasing velocity of the diverted air flow. In some implementations, the lateral extent e of the exit aperture may be no more than 90% or no more than 80% of the lateral extent f of the entrance aperture. Similar control of the diverted air flow may be achieved by the cross sectional area E of the exit aperture 38 being less than, for example no more than 80% or no more than 50% of the cross sectional area F of the entrance aperture 40, where these cross section areas are measured perpendicular to the direction of air flow within each aperture. The cross sectional area of the entrance aperture may for example be from about 5 to 100 cm².

[0052] Figures 4a to 4e depict in cross sectional view from the side of the refrigerator various ways in which the air flow diverter 30 may be implemented, for example within the context of figures 1 to 3, to divert a portion of the chilled air supply S and direct the diverted portion within the interior 14 towards the slit 28. Structures within the plane of each figure are largely depicted in solid lines. Some structures outside of the plane of each figure also depicted for context, but may be represented in broken lines, and the same scheme is used for the arrows depicting air flows.

[0053] As already noted, the air curtain vent 24 may typically comprise a grill 42 through which the chilled air is expelled in a downwards direction to form the air curtain. The grill may typically be formed of one or more metal and/or plastics material, and comprises a plurality of passages for the chilled air to flow through. The passages may be defined in various ways. A honeycomb structured grill in which hexagonal passages are defined by interlocking vanes or adjacent hexagonal tubes is frequently used, but the passages may be square, rectangular, circular and/or have other shapes. Typically each passage will be considerably longer in the direction of air flow than it is wide, for example at least twice or at least three times as long, in order to impart more directionality to the air flow so as to form an effective air curtain.

[0054] In figures 4a and 4b the air flow diverter 30 comprises or is implemented as a diverter duct 31 comprising the entrance and exit apertures as already described above. The diverter duct may be formed of one or more metal, plastics or other suitable materials. The entrance aperture 40 of the diverter duct 31 is arranged to receive the portion of chilled air supply, for example from the vicinity of the grill 42, and the exit aperture 38 of the diverter duct is arranged to release the diverted portion towards the slit 18, typically from below the grill as variously described above. Note that the air flow diverter may be implemented as such a diverter duct whether or not the air curtain vent includes a grill 42.

[0055] In figure 4a the entrance aperture 40 of the diverter duct 31 is located beneath the grill 42 so as to receive a portion of the chilled air supply which has already passed through the grill. This implementation is particularly useful where the air flow diverter 30 is to be retrofitted to an existing or already installed or deployed refrigerator. For example, the diverter duct 31 may comprise flanges extending forwards and backwards from the grill as seen in figure 4a, with fasteners such as screws 44 being used to secure the flanges to the housing both forward and backward of the grill.

[0056] In figure 4b the entrance aperture 40 of the diverter duct 31 is located above the grill 42, within the roof duct 17, so that the diverter duct passes through an aperture in the grill. The diverter duct may again comprise flanges extending forwards and backwards from the grill as seen in figure 4b, with fasteners such as screws 44 being used to secure the flanges to the housing both forward and backward of the grill as shown in the figure.

[0057] In figure 4c, rather than being mounted at the grill 42 as seen in figures 4a and 4b, the diverter duct 31 is positioned rearward from the grill 42, for example passing through the ceiling 15 of the interior space behind the grill and into the roof duct 17 so as to intercept a portion of the chilled air supply upstream from the grill. In this case, the air flow diverter 30 or diverter duct 31 may further comprise a rising deflector 46 which extends up into the chilled air supply flow within the roof duct 17 above the ceiling 15 to assist in diverting the air flow into the main body of the diverter duct. To prevent chilled air flow through the grill 42 from disturbing the portion of chilled air supply diverted towards the slit, the diverter duct may extend towards the slit far enough that the diverted portion of the chilled air supply is released beyond the air curtain 22. Alternatively, and as shown in figure 4c, the air flow diverter may further comprise a baffle 48 to cover a portion of the grill adjacent to the diverter duct to block passage of the chilled air through a part of the grill which would cause disturbance of the diverted air flow.

[0058] In figure 4d, instead of a duct being used to divert the portion of chilled air, the air flow diverter 30 comprises an oblique deflector or deflector plate 50 which descends underneath the grill in a direction towards the slit 28 to thereby redirect the portion of chilled air towards the slit after it has passed through the grill immediately above the oblique or descending deflector 50. Conveniently, the oblique deflector 50 may be coupled to the ceiling by fasteners 44 such as screws into the ceiling behind the grill. The descending deflector could be a substantially planar component, or could be formed in a variety of shapes to better direct the portion of chilled air towards the slit.

[0059] In figure 4e, the air flow diverter 30 is provided by an adaption of the grill 42 itself. In particular, the air flow diverter 30 comprises a subset of the passages of the grill which are oriented in a different direction to those passages of the grill which provide the air curtain. For example, the passages of the grill which are comprised in or form the air flow diverter are oriented towards the slit or towards the doors, so as to redirect a portion of the chilled air supply in that direction. These passages could for example be oriented so that their central axes have an elevation angle β as shown in figure 4e which is more than (that is closer to horizontal than) -80° or more than -70°, or between -70° and -20° for example. These passages of the air flow diverter could comprise passages from at or near the front of the grill across most or all of the full depth to the back of the grill as shown in figure 4e, or could extend only part way back with passages behind the air flow diverter being substantially vertical or otherwise oriented to provide a part of the downwardly directed air curtain.

[0060] Whereas figures 4a to 4e have depicted various ways of using an air flow diverter 30 or more particularly a diverter duct 31, to redirect a portion of the chilled air supply internally through the interior space towards the slit, figure 5 depicts in cross sectional view how this may be achieved by channelling a portion of the chilled air supply S to an exit aperture which is outside the housing, and directing this portion of the chilled air supply downwardly towards and/or along the slit. In figure 5 this is achieved by providing the air flow diverter 30 as a diverter duct 31 which is arranged to receive a portion of the chilled air supply at an entrance aperture 30 of the duct which is typically within the roof duct 17 (so chilled air which would otherwise pass through the air curtain vent 42 to form the air curtain), and to channel the diverted portion of the chilled air supply to an exit aperture 38 of the duct which is located externally to the housing, and typically above the slit and/or the doors, for example through a head of the housing which is located above the adjacent doors and/or above the slit. The exit aperture 38 then directs the diverted portion of the chilled air supply downwards in front of, along, or to the slit 28. Without wishing to be bound by any particular detailed fluid flow regime, this appears to achieve a similar effect to that of the already described chilled air jets in improving efficiency of the refrigerator, but the mechanism may be at least in part one of air flow drawn in through the slit being one of drawing in external air which is already at least partly formed of or mixed with the portion of chilled air.

[0061] The embodiments depicted in figures 2 to 5 all make use of an air curtain 22 formed using an air curtain vent 24 to deliver a chilled air supply S downwardly from behind the front of the housing 10. However, the invention can also be implemented in refrigerators 10 in which no such air curtain is formed, and in which the air flow diverter is instead arranged to receive a portion of the chilled air supply S which is more generally delivered into the interior space 14 using a chilled air supply vent. Such a chilled air supply vent may typically be provided on a back wall of the interior space or of the housing, close to or at the top of the interior space, for example within the top 10% to 25% of the interior space.

[0062] Such an arrangement is depicted in cross section in figure 6. As before, the refrigerator 10 comprises a housing 12, and at least first and second doors 18 or other closures as described above provide access to the interior space 14 within the housing which may also contain elements such as shelves, air guides and so forth as already described. In this arrangement no air curtain vent is provided behind the doors, but instead a chilled air supply S is delivered to the interior space through one or more other vents, in this case a chilled air supply vent 52 located towards the back of the interior space, and in this case located on the rear wall of the interior space or housing.

[0063] An air flow diverter 31 then receives a portion of the chilled air supply S either from the air supply vent 52, proximally to the air supply vent 52, or in some other way for example through a roof duct (not shown in this figure), and as in the previous examples directs the received portion of the chilled air supply towards the slit, so as to reduce exchange of air through the slit when both of the doors are closed. The various possible geometries and other properties of the air flow, entrance and exit apertures and so forth as already described above continue to apply.

[0064] Figure 7 provides a CAD drawing perspective view cut through an upper portion of a refrigerator 10 implementing an air flow diverter 30 in the form of a diverter duct 31 similar to that shown in figure 4a. The diverter duct is secured below a portion of the grill 42 (not depicted in this figure) of elongate air curtain vent 24. In this arrangement, the entrance aperture 40 of the air flow diverter has an area of about 100 cm², and the exit aperture has an area of about 20 cm² and comprises a plurality of exit vanes 36 arranged to release the diverted portion of chilled air towards the slit 28 over a simultaneous range of elevation angles α from about -20° to about 0°.

[0065] The air flow diverter 30 of figure 7 was used in realistic physical testing of a refrigerator unit fully loaded with M-packages as specified by the BS EN ISO 23953-2015 "Refrigerated Display Cabinets" standard. A total of 84 temperature sensors, 2 pressure sensors, and 1 refrigerant flow meter were used for the tests, with product temperatures being measured in the centre of each M-package. The refrigerator unit used was a typical standard multi-deck refrigerator display cabinet commonly used in major supermarkets, and similar to that shown in figure 1, but with four frameless transparent doors, and with an air flow diverter 30 installed behind each the top of each boundary between a pair of doors, so three air flow diverters in total. Door openings were performed with robotic arms which could be programmed to provide opening frequencies in accordance with the above standard or to emulate door opening patterns in a real store environment. The refrigerator unit was located in a test chamber with an ambient dry bulb temperature of 20°C, 50% relative humidity, and with a mean horizontal air velocity (cross flow) in the range between 0.1 and 0.2 ms^-1.

[0066] Once steady state conditions were achieved, the tests were carried out for a 24-hour period. Temperature and energy performance of the refrigerator unit was established from data during the 24-hour tests using the methodology outlined in BS EN ISO 23953-2015, pages 10 and 11.

[0067] The results show the air flow diverters provide an energy saving in the form of reduced REC (Refrigeration Energy Consumption) measured before and after the installation of the air flow diverters 30. To ensure the data was reliable, a total of five baseline tests were conducted before installing the air flow diverters, and seven full tests with the air flow diverters installed and in operation. The full tests were carried out both with and without air curtain guiding aerofoils mounted to the ends of the five shelves to show energy savings in both scenarios.

[0068] For these tests, the average REC (in kWh per 24 hours) was 9.07 for the baseline scenario (no air flow diverters or aerofoils), 7.84 for the full tests with air flow diverters alone (an energy saving of 14%), and 6.48 for the full test with both air flow diverters and aerofoils installed (an energy saving of 29%).

[0069] Although particular embodiments of the invention have been described, the skilled person will appreciate that a variety of modification and changes may be made without departing from the scope of the invention as claimed.

[0070] Various embodiments of the invention are provided as set out in the following numbered clauses.

[0071] Clause 1. A refrigerator comprising:

a housing defining an interior space to be refrigerated;

adjacent first and second doors mounted at a front of the housing to provide access to the interior space when either or both of the doors are open, the first and second doors defining a slit between them when both are closed;

an elongate air curtain vent extending across a ceiling of the interior space and arranged to direct a chilled air supply downwards within the interior space to form an air curtain behind the front of the housing; and

an air flow diverter arranged to divert a portion of the chilled air supply towards the slit instead of forming part of the air curtain, so as to reduce exchange of air through the slit.

[0072] Clause 2. The refrigerator of clause 1 wherein the portion of the chilled air supply is directed towards the slit by the air flow diverter as a jet of chilled air.

[0073] Clause 3. The refrigerator of clause 1 or 2 wherein the adjacent first and second doors are both hinged to the front of the housing.

[0074] Clause 4. The refrigerator of any of clauses 1 to 3 wherein the adjacent first and second doors are frameless transparent doors.

[0075] Clause 5. The refrigerator of any preceding clause wherein the slit is defined along substantially the full vertical length between the adjacent first and second doors.

[0076] Clause 6. The refrigerator of any preceding clause wherein the chilled air supply is provided to the air curtain vent and to the air flow diverter via a roof duct located above the interior space.

[0077] Clause 7. The refrigerator of any preceding clause wherein the air flow diverter is arranged to divert the portion of the chilled air supply forwards within the interior space towards the slit.

[0078] Clause 8. The refrigerator of clause 7 where the air flow diverter diverting the portion of the chilled air supply forwards within the interior space comprises the air flow diverter directing the portion of the chilled air supply forwards towards the slit at an elevation angle α, or at a range of elevation angles α, where -90° <= α <= 0°, or -70°<= α <= 0°, or -70° <= α <= -20°, or α > -90° , or α > -70°, where 0° is horizontal and negative elevations are downwards.

[0079] Clause 9. The refrigerator of clause 7 or 8 wherein the air flow diverter diverting the portion of the chilled air supply forwards within the interior space comprises the air flow diverter releasing the portion of the chilled air towards the slit at a location closer to the slit than the air curtain vent.

[0080] Clause 10. The refrigerator of any of clauses 7 to 9 wherein the air curtain vent comprises an elongate grill through which the chilled air supply is delivered into the interior space to form the air curtain, the grill comprising a plurality of passages for directing the chilled air passing through the grill.

[0081] Clause 11. The refrigerator of clause 10 wherein the air flow diverter comprises a diverter duct arranged to receive the portion of the chilled air supply and to divert the received portion of the chilled air supply towards the slit.

[0082] Clause 12. The refrigerator of clause 11 wherein the diverter duct is positioned below the grill and arranged to receive the portion of the chilled air supply from the grill.

[0083] Clause 13. The refrigerator of clause 11 wherein the diverter duct passes through an aperture in the grill and is arranged to receive the portion of the chilled air supply from above the grill.

[0084] Clause 14. The refrigerator of clause 11 wherein the diverter duct is mounted behind the grill so as to receive the portion of the chilled air supply before the chilled air supply arrives at the grill.

[0085] Clause 15. The refrigerator of clause 10 wherein the air flow diverter comprises an oblique deflector which descends beneath the grill in a direction towards the slit.

[0086] Clause 16. The refrigerator of clause 10 wherein the air flow diverter comprises a plurality of the passages of the grill which are oriented towards the slit.

[0087] Clause 17. The refrigerator of any of clauses 1 to 6 wherein:

the air flow diverter comprises a diverter duct arranged to receive the portion of the chilled air supply, and to channel the diverted portion of the chilled air supply to an exit aperture located outside the housing above the slit,

the exit aperture being arranged to direct the diverted portion of the chilled air supply downwards in front of the slit, externally to the first and second doors.

[0088] Clause 18. The refrigerator of any preceding clause wherein the air flow diverter extends across the width of the slit, or across an upward projection of the slit, in front elevational view of the refrigerator.

[0089] Clause 19. The refrigerator of any preceding clause wherein the air flow diverter extends laterally for one or more of: no more than 10 cm; and more than 1 cm.

[0090] Clause 20. The refrigerator of any preceding clause wherein the portion of the chilled air supply diverted towards the slit by the air flow diverter is from 1% to 10% of the total chilled air supply.

[0091] Clause 21. The refrigerator of any preceding clause wherein the air flow diverter comprises an entrance aperture arranged to collect the portion of the chilled air from the chilled air supply, and an exit aperture arranged to direct the portion of the chilled air towards the slit, wherein at least one of:

the lateral extent of the entrance aperture is greater than the lateral extent of the exit aperture; and

the cross-sectional area of the entrance aperture is greater than the cross-sectional area of the exit aperture,

such that the flow of the portion of chilled air within the air flow diverter is narrowed.

[0092] Clause 22. A refrigerator comprising:

a housing defining an interior space to be refrigerated;

adjacent first and second doors mounted at a front of the housing to provide access to the interior space when either or both of the doors are open, the first and second doors defining a slit between them when both are closed;

a chilled air supply vent disposed in an upper half of the interior space and arranged to deliver a chilled air supply into the interior space; and

an air flow diverter arranged to receive a portion of the chilled air supply, and to divert the portion of the chilled air supply towards the slit, so as to reduce exchange of air through the slit when both of the doors are closed.

[0093] Clause 23. The refrigerator of clause 22 wherein the chilled air supply vent is an elongate air curtain vent extending across a ceiling of the interior space and arranged to direct the chilled air supply downwards within the interior space to form an air curtain behind the front of the housing; and
the air flow diverter is arranged to divert the portion of the chilled air supply in the form towards the slit instead of forming part of the air curtain.

[0094] Clause 24. The refrigerator of clause 22 wherein the chilled air supply vent is disposed in a back wall of the housing, and the air flow diverter is arranged to channel the portion of the chilled air supply forwards from the back wall of the housing and to release the portion of the chilled air supply proximally to the slit.

[0095] Clause 25. The refrigerator of any of clauses 22 to 24 wherein the portion of the chilled air supply is directed towards the slit in the form of a jet, the jet being directed to, towards, or along the slit in the upper half, or in the upper quarter, of the slit.

[0096] Clause 26. A method of operating a refrigerator which comprises a housing defining an interior space to be refrigerated, and at least adjacent first and second doors mounted at a front of the housing to provide access to the interior space when either or both doors are opened, the first and second doors defining a slit between them when both are closed,
the method comprising directing a jet of chilled air, within or externally to the interior space, to, towards, or along the slit so as to reduce exchange of air through the slit between an environment within which the refrigerator is housed and the interior space of the refrigerator.

[0097] Clause 27. The method of clause 26 wherein the jet is directed to, towards, or along the slit in the upper half, or in the upper quarter, of the slit.

[0098] Clause 28. The method of clause 26 or 27 further comprising forming an air curtain within the interior space behind the front of the housing using a chilled air supply, wherein directing the jet of chilled air to, towards or along the slit comprises diverting a portion of the chilled air supply to form the jet instead of the portion of the chilled air supply being used to form the air curtain.

[0099] Clause 29. The refrigerator of clause 26 or 27 wherein the interior space is cooled using a chilled air supply delivered at least in part via a chilled air supply vent disposed in a back wall of the housing, and the air flow diverter is arranged to channel the portion of the chilled air supply forwards from the back wall of the housing and to form the jet of chilled air proximally to the slit.

[0100] Clause 30. The method of any of clauses 26 to 29 wherein the first and second doors are frameless transparent doors of the refrigerator.

[0101] Clause 31. A method of adapting a refrigerator to reduce energy consumption, the refrigerator comprising first and second doors having a slit therebetween at least when both are closed and an air curtain vent located behind the doors to form an air curtain of chilled air, the method comprising installing an air flow diverter at the air curtain vent to redirect a portion of the chilled air towards the slit so as to reduce exchange of air through the slit between an environment within which the refrigerator is located and an interior space of the refrigerator.

Claims

1. A refrigerator comprising:

a housing defining an interior space to be refrigerated;

adjacent first and second doors mounted at a front of the housing to provide access to the interior space when either or both of the doors are open, the first and second doors defining a slit between them when both are closed;

an elongate air curtain vent extending across a ceiling of the interior space and arranged to direct a chilled air supply downwards within the interior space to form an air curtain behind the front of the housing; and

an air flow diverter arranged to divert a portion of the chilled air supply, optionally as a jet of chilled air, towards the slit instead of forming part of the air curtain, so as to reduce exchange of air through the slit.

2. The refrigerator of claim 1 wherein one or more of: the adjacent first and second doors are both hinged to the front of the housing; the adjacent first and second doors are frameless transparent doors; and the slit is defined along substantially the full vertical length between the adjacent first and second doors.

3. The refrigerator of any preceding claim wherein the air flow diverter is arranged to divert the portion of the chilled air supply forwards within the interior space towards the slit, and optionally wherein diverting the portion of the chilled air supply forwards within the interior space comprises the air flow diverter releasing the portion of the chilled air towards the slit at a location closer to the slit than the air curtain vent.

4. The refrigerator of claim 3 where the air flow diverter diverting the portion of the chilled air supply forwards within the interior space comprises the air flow diverter directing the portion of the chilled air supply forwards towards the slit at an elevation angle α, or at a range of elevation angles α, where -90° <= α <= 0°, or -70°<= α <= 0°, or -70° <= α <= - 20°, or α > -90° , or α > -70°, where 0° is horizontal and negative elevations are downwards.

5. The refrigerator of claims 3 or 4 wherein the air curtain vent comprises an elongate grill through which the chilled air supply is delivered into the interior space to form the air curtain, the grill comprising a plurality of passages for directing the chilled air passing through the grill.

6. The refrigerator of claim 5 wherein the air flow diverter comprises a diverter duct arranged to receive the portion of the chilled air supply and to divert the received portion of the chilled air supply towards the slit, and optionally wherein either the diverter duct is positioned below the grill and arranged to receive the portion of the chilled air supply from the grill, or the diverter duct passes through an aperture in the grill and is arranged to receive the portion of the chilled air supply from above the grill, or the diverter duct is mounted behind the grill so as to receive the portion of the chilled air supply before the chilled air supply arrives at the grill.

7. The refrigerator of claim 5 wherein either the air flow diverter comprises an oblique deflector which descends beneath the grill in a direction towards the slit, or wherein the air flow diverter comprises a plurality of the passages of the grill which are oriented towards the slit.

8. The refrigerator of claim 1 or 2 wherein:

the air flow diverter comprises a diverter duct arranged to receive the portion of the chilled air supply, and to channel the diverted portion of the chilled air supply to an exit aperture located outside the housing above the slit,

the exit aperture being arranged to direct the diverted portion of the chilled air supply downwards in front of the slit, externally to the first and second doors.

9. The refrigerator of any preceding claim wherein one or more of: the air flow diverter extends across the width of the slit, or across an upward projection of the slit, in front elevational view of the refrigerator; the air flow diverter extends laterally for no more than 10 cm and/or more than 1 cm; and the portion of the chilled air supply diverted towards the slit by the air flow diverter is from 1% to 10% of the total chilled air supply.

10. The refrigerator of any preceding claim wherein the air flow diverter comprises an entrance aperture arranged to collect the portion of the chilled air from the chilled air supply, and an exit aperture arranged to direct the portion of the chilled air towards the slit, wherein the lateral extent of the entrance aperture is greater than the lateral extent of the exit aperture and/or the cross-sectional area of the entrance aperture is greater than the cross-sectional area of the exit aperture, such that the flow of the portion of chilled air within the air flow diverter is narrowed.

11. A refrigerator comprising:

a housing defining an interior space to be refrigerated;

adjacent first and second doors mounted at a front of the housing to provide access to the interior space when either or both of the doors are open, the first and second doors defining a slit between them when both are closed;

a chilled air supply vent disposed in an upper half of the interior space and arranged to deliver a chilled air supply into the interior space; and

an air flow diverter arranged to receive a portion of the chilled air supply, and to divert the portion of the chilled air supply towards the slit, so as to reduce exchange of air through the slit when both of the doors are closed.

12. The refrigerator of claim 11 wherein either:

the chilled air supply vent is an elongate air curtain vent extending across a ceiling of the interior space and arranged to direct the chilled air supply downwards within the interior space to form an air curtain behind the front of the housing, and the air flow diverter is arranged to divert the portion of the chilled air supply in the form towards the slit instead of forming part of the air curtain, or:

the chilled air supply vent is disposed in a back wall of the housing, and the air flow diverter is arranged to channel the portion of the chilled air supply forwards from the back wall of the housing and to release the portion of the chilled air supply proximally to the slit.

13. A method of operating a refrigerator which comprises a housing defining an interior space to be refrigerated, and at least adjacent first and second doors mounted at a front of the housing to provide access to the interior space when either or both doors are opened, the first and second doors defining a slit between them when both are closed,
the method comprising directing a jet of chilled air, within or externally to the interior space, to, towards, or along the slit so as to reduce exchange of air through the slit between an environment within which the refrigerator is housed and the interior space of the refrigerator.

14. The method of claim 13 either:

further comprising forming an air curtain within the interior space behind the front of the housing using a chilled air supply, wherein directing the jet of chilled air to, towards or along the slit comprises diverting a portion of the chilled air supply to form the jet instead of the portion of the chilled air supply being used to form the air curtain; or

wherein the interior space is cooled using a chilled air supply delivered at least in part via a chilled air supply vent disposed in a back wall of the housing, and the air flow diverter is arranged to channel the portion of the chilled air supply forwards from the back wall of the housing and to form the jet of chilled air proximally to the slit.

15. A method of adapting a refrigerator to reduce energy consumption, the refrigerator comprising first and second doors having a slit therebetween at least when both are closed and an air curtain vent located behind the doors to form an air curtain of chilled air, the method comprising installing an air flow diverter at the air curtain vent to redirect a portion of the chilled air towards the slit so as to reduce exchange of air through the slit between an environment within which the refrigerator is located and an interior space of the refrigerator.

Amended claims

Amended claims in accordance with Rule 137(2) EPC.

1. A refrigerator (10) comprising:

a housing (12) defining an interior space (14) to be refrigerated;

adjacent first and second doors (18) mounted at a front (16) of the housing to provide access to the interior space when either or both of the doors are open, the first and second doors defining a slit (28) between them when both are closed;

an elongate air curtain vent (24) extending across a ceiling (15) of the interior space and arranged to direct a chilled air supply downwards within the interior space to form an air curtain (22) behind the front of the housing; and

an air flow diverter (30) arranged to divert a portion of the chilled air supply, optionally as a jet of chilled air, towards the slit (28) instead of forming part of the air curtain (22), so as to reduce exchange of air through the slit.

2. The refrigerator of claim 1 wherein one or more of: the adjacent first and second doors (18) are both hinged to the front of the housing; the adjacent first and second doors are frameless transparent doors; and the slit (28) is defined along substantially the full vertical length between the adjacent first and second doors.

3. The refrigerator of any preceding claim wherein the air flow diverter (30) is arranged to divert the portion of the chilled air supply forwards within the interior space (14) towards the slit (28), and optionally wherein diverting the portion of the chilled air supply forwards within the interior space comprises the air flow diverter releasing the portion of the chilled air towards the slit at a location closer to the slit than the air curtain vent.

4. The refrigerator of claim 3 where the air flow diverter (30) diverting the portion of the chilled air supply forwards within the interior space comprises the air flow diverter directing the portion of the chilled air supply forwards towards the slit (28) at an elevation angle α, or at a range of elevation angles α, where -90° <= α <= 0°, or -70°<= α <= 0°, or -70° <= α <= -20°, or α > -90° , or α > -70°, where 0° is horizontal and negative elevations are downwards.

5. The refrigerator of claims 3 or 4 wherein the air curtain vent (24) comprises an elongate grill (42) through which the chilled air supply is delivered into the interior space to form the air curtain, the grill comprising a plurality of passages for directing the chilled air passing through the grill.

6. The refrigerator of claim 5 wherein the air flow diverter (30) comprises a diverter duct (31) arranged to receive the portion of the chilled air supply and to divert the received portion of the chilled air supply towards the slit (28), and optionally wherein either the diverter duct is positioned below the grill and arranged to receive the portion of the chilled air supply from the grill (42), or the diverter duct passes through an aperture in the grill and is arranged to receive the portion of the chilled air supply from above the grill, or the diverter duct is mounted behind the grill so as to receive the portion of the chilled air supply before the chilled air supply arrives at the grill.

7. The refrigerator of claim 5 wherein either the air flow diverter comprises an oblique deflector (50) which descends beneath the grill (42) in a direction towards the slit (28), or wherein the air flow diverter comprises a plurality of the passages of the grill which are oriented towards the slit.

8. The refrigerator of claim 1 or 2 wherein:

the air flow diverter (30) comprises a diverter duct (31) arranged to receive the portion of the chilled air supply, and to channel the diverted portion of the chilled air supply to an exit aperture (38) located outside the housing above the slit (28),

the exit aperture being arranged to direct the diverted portion of the chilled air supply downwards in front of the slit, externally to the first and second doors (18).

9. The refrigerator of any preceding claim wherein one or more of: the air flow diverter (30) extends across the width of the slit (28), or across an upward projection of the slit (28), in front elevational view of the refrigerator; the air flow diverter (30) extends laterally for no more than 10 cm and/or more than 1 cm; and the portion of the chilled air supply diverted towards the slit (28) by the air flow diverter (30) is from 1% to 10% of the total chilled air supply.

10. The refrigerator of any preceding claim wherein the air flow diverter (30) comprises an entrance aperture (40) arranged to collect the portion of the chilled air from the chilled air supply, and an exit aperture (38) arranged to direct the portion of the chilled air towards the slit, wherein the lateral extent of the entrance aperture (40) is greater than the lateral extent of the exit aperture (38) and/or the cross-sectional area of the entrance aperture (40) is greater than the cross-sectional area of the exit aperture (38), such that the flow of the portion of chilled air within the air flow diverter (30) is narrowed.

11. A method of operating a refrigerator which comprises a housing defining an interior space to be refrigerated, and at least adjacent first and second doors mounted at a front of the housing to provide access to the interior space when either or both doors are opened, the first and second doors defining a slit between them when both are closed,
the method comprising directing a jet of chilled air, within or externally to the interior space, to, towards, or along the slit so as to reduce exchange of air through the slit between an environment within which the refrigerator is housed and the interior space of the refrigerator.

12. The method of claim 11 either:

further comprising forming an air curtain within the interior space behind the front of the housing using a chilled air supply, wherein directing the jet of chilled air to, towards or along the slit comprises diverting a portion of the chilled air supply to form the jet instead of the portion of the chilled air supply being used to form the air curtain; or

wherein the interior space is cooled using a chilled air supply delivered at least in part via a chilled air supply vent disposed in a back wall of the housing, and an air flow diverter is arranged to channel a portion of the chilled air supply forwards from the back wall of the housing and to form the jet of chilled air proximally to the slit.

13. A method of adapting a refrigerator to reduce energy consumption, the refrigerator comprising at least adjacent first and second doors (18) having a slit therebetween at least when both are closed, and an air curtain vent (24) located behind the doors to form an air curtain (22) of chilled air, the method comprising installing an air flow diverter (30) at the air curtain vent to redirect a portion of the chilled air towards the slit so as to reduce exchange of air through the slit between an environment within which the refrigerator is located and an interior space of the refrigerator.

14. The method of claim 13 wherein the air flow diverter (30) is arranged and installed to divert the portion of the chilled air supply forwards within an interior space (14) of the refrigerator towards the slit (28), and optionally wherein the air flow diverter is arranged and installed to release the portion of the chilled air towards the slit at a location closer to the slit than the air curtain vent (24).

15. The method of any of claims 11 to 14 wherein one or more of: the adjacent first and second doors (18) are both hinged to the front of the housing; the adjacent first and second doors are frameless transparent doors; and the slit (28) is defined along substantially the full vertical length between the adjacent first and second doors.

Drawing