GB2404436A

GB2404436A - Nozzle for a ceiling mounted ventilation diffuser

Info

Publication number: GB2404436A
Application number: GB0316492A
Authority: GB
Inventors: John James Mawdsley
Original assignee: GILBERTS
Current assignee: GILBERTS
Priority date: 2003-07-15
Filing date: 2003-07-15
Publication date: 2005-02-02
Anticipated expiration: 2023-07-15
Also published as: GB0316492D0; GB2404436B

Abstract

A ventilation device/nozzle 4 for delivering air into a space, the nozzle 4 comprising an inlet 6 for air, an outlet for air and an air impingement surface 16 positioned between the inlet 6 and outlet, said air impingement surface 16 having a free edge 30 which defines an edge of a lower part of the outlet, said free edge 30 extending between a first point and a second point, wherein the length of the free edge 30 is greater than the distance between the first and second points. The free edge 30 of the nozzle 4 may include a convex region 26 with first and second regions 18, 20 either side of and contiguous with the convex region 26. The free edge 30 may be symmetrical. The convex region 26 may protrude from the impingement surface 16 to create a convex area 26. The nozzle 4 may be either round or rectangular and elongate (figures 8-11) in cross-section. There may be provided an assembly/ceiling tile 2 comprising an array of the nozzles 4 with the nozzles 4 configured such that a swirling air pattern is produced.

Description

j 2404436 Ventilation This invention relates to ventilation and

particularly, although not exclusively, relates to a ventilation device for arrangement in or adjacent a ceiling of a confined space, for example a room, to deliver air into the room.

Ceiling diffusers are known which comprise an array of nozzles arranged in a tile which is incorporated into a lo ceiling of a room. The nozzles define an outlet end of an air conditioning system and are arranged to direct hot or cold air into the room. However, the design of known nozzles tends to be driven primarily by aesthetic considerations, rather than technical considerations.

Thus, many known nozzles, whilst looking stylish, may jet air at too great a velocity too deeply into the room. As a consequence, when cool air for example is being delivered into the room, the cool air penetrates into the occupied zone of the room so that personnel in the occupied zone may be directly impinged by relatively cool air.

A problem with which the present invention is concerned is to provide a nozzle for use in a ceiling diffuser which is 2s designed such that room air is induced and/or entrained in fresh air issuing therefrom thereby to mix the room air with the fresh air and reduce the velocity at which the fresh air enters the occupied zone.

It is an object of the present invention to address the aforementioned problem.

According to a first aspect of the invention, there is provided a ventilation device for delivering air into a confined space, said device comprising: an inlet for air; an outlet for air; an air impingement surface positioned between the lo inlet and outlet and being arranged to be impinged by air entering the device via said inlet, said air impingement surface having a free edge which defines an edge of a lower part of the outlet, said free edge extending between a first point and a second point, wherein the length of the free edge is greater than the linear distance between said first and second points.

Suitably, the ratio of the length of the free edge to the linear distance between said first and second points is at least 1.1, preferably at least 1.2, more preferably at least 1.5. The ratio may be less than 5, preferably less than 3.

Said free edge preferably includes at least one convex region. Said free edge may include first and second regions on opposite sides of said convex region. Said first and second regions may be independently selected from straight or curved regions. Preferably, said first and second regions are curved. They may be concave. They are preferably contiguous with said convex region. Said free edge is preferably substantially symmetrical about a mirror plane which bisects the free edge.

When said free edge includes a said convex region, said convex region preferably extends inwardly from said free edge across said air impingement surface thereby to define a convex area. An underside of said air impingement surface which preferably faces downwardly in use, preferably includes a concave area which corresponds to said convex area. Said convex area preferably tapers inwardly on moving inwardly away from said free edge.

Said convex area suitably represents a bulbous projection lo from said air impingement surface which increases the area of said surface compared to a corresponding surface in the absence of said convex area. Said convex area preferably extends greater than 50%, more preferably greater than 60% of the distance between said free edge (at an outermost point) and an opposite edge of the device directly opposite said outermost point of the free edge.

Part of said air impingement surface may slope downwardly in use on moving from said outer edge towards said free edge (at an outermost point) . Preferably, said regions of said air impingement surface on opposite sides of said convex area may slope downwardly as aforesaid.

Said free edge preferably faces generally in the direction of air flow out of the device.

In a first embodiment, said device may include a said free edge which includes a single convex region as described, optionally bounded by first and second regions as described. In this case, said convex region may lie on a central axis, for example a diameter of the device.

In said first embodiment, said free edge may appear convex when viewed in a first direction (e.g. facing the direction of air flow out of the device). When viewed in a direction perpendicular to said first direction (e.g. from above the device and/or in a direction which faces the main plane of the air impingement surface), said free edge may be arcuate in shape, suitably with one end of the arc being defined by said first point and another end of the arc being defined by said second point.

Said device of said first embodiment is preferably substantially circular in cross-section. Said inlet of the device is preferably substantially circular in cross- section.

In a second embodiment, said device may include a said free edge which includes a plurality of convex regions, optionally spaced apart by linear or curved regions. The depth of the convex regions may be substantially identical. Preferably, a plurality of said convex regions are of exactly the same size and shape as one another.

Said device of said second embodiment is preferably elongate and is preferably substantially rectangular in 2s cross-section. Said inlet of the device is preferably elongate and, more preferably, substantially rectangular in cross-section.

In said second embodiment, said free edge may appear convex when viewed in a first direction (e.g. facing the direction of air flow out of the device); when viewed in a direction perpendicular to said first direction (e.g. from above the device and/or in a direction which faces the s main plane of the air impingement surface), said free edge may appear linear with one end of such a linear free edge being defined by said first point and another end being defined by said second point.

Preferably, said air impingement surface of the device has a surface area which is greater than the area of said inlet. The ratio of the surface area of the air impingement surface to that of said inlet may be greater lo than 1.05. The ratio may be less than 2, preferably less than 1.5. The surface area of said air impingement surface suitably refers to regions of said air impingement surface which extend, in use, transverse to the direction of air flow into the device via said inlet.

Said device preferably includes a spacer means arranged to space the air impingement surface from said inlet. Said spacer means preferably extends, in use, in the direction of air flow into the device. Said device preferably includes a lateral region (e.g. a collar) which in use is suitably arranged to abut a region outside an opening (for example in a ceiling member such as a ceiling tile) in which the device may be arranged. Said lateral region preferably includes an endless wall which suitably defines an outer boundary of the device. Said spacer means preferably extends between the air impingement surface and said lateral region. Upstream of said lateral region, the device preferably includes securement means for securing said device in an opening, for example a tile. Sais securement means and/or said lateral region preferably define said inlet.

Said device is preferably arranged in use for air to enter the device via said inlet in a first direction and to exit the device via said outlet in a second direction, wherein! said second direction is transverse to said first direction. In use, air input into the device preferably turns through an angle of greater than 75 , preferably greater than 85 between said inlet and outlet. It preferably turns through less than 120 preferably less than 100 . Said device is preferably arranged to deliver lo a divergent substantially unidirectional jet of air via said outlet.

Said air impingement surface of the device is preferably in a fixed, unadjustable position within the device. The only moving parts of the device are preferably parts which are resilient (e.g. to facilitate securement of the device in position).

According to a second aspect of the invention, there is provided an assembly comprising a plurality of ventilation devices according to said first aspect.

Said devices may be arranged adjacent to one another.

Each device may be fed from the same air delivery device.

In a first embodiment (suitably in said first embodiment of the first aspect) said plurality of devices are preferably arranged in an array. Preferably, the array includes at least 10, preferably at least 20, devices. I The number may be less than 100, preferably less than 50.

The array may be configured such that a swirling air pattern is produced by combination of air exiting from the devices in the array. Said devices are preferably secured within a ceiling tile.

In a second embodiment (suitably in said second embodiment i of the first aspect) an assembly may include at least two devices of the first aspect. Such devices are preferably secured together.

According to a third aspect of the invention, there is provided a method of delivering air into a confined space wherein a ventilation device according to said first] lo aspect is arranged in the space, preferably at or adjacent a ceiling thereof. The method preferably includes arranging said device so that its outlet is arranged to direct air substantially parallel to the ceiling.

Any feature of any aspect of any invention or embodiment described herein may be combined with any feature of any aspect of any other invention or embodiment herein mutatis mu tandi s.

Specific embodiments of the invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a perspective view of an array of nozzles secured in a ceiling tile; Figure 2 is a plan view of a single nozzle of the array; Figure 3 is a perspective view of the nozzle; Figure 4 is a front view in the direction of arrow IV of figure 2; Figure 5 is a side view in the direction of arrow V of figure 2; Figure 6 is a side view of the nozzle secured in a ceiling and showing air flow out of and around the nozzle; Figure 7 a is view in the direction of arrow VII of figure 6; lo Figure 8 is a perspective view of a linear diffuser; Figure 9 is a front view of the linear diffuser; Figures 10 and 11 are perspective views of other linear diffusers; and Figure 12 illustrates how nozzles may be arranged to generate a swirl effect.

In the figures, the same or similar parts are annotated with the same reference numerals.

Referring to figure 1, a ceiling tile 2 includes an array of identical nozzles 4 which are releasably secured therein. The nozzles are connected upstream to an air conditioning apparatus so that hot or cold air can be delivered via each nozzle into a room to heat or cool the room. In general terms, each nozzle is designed and arranged to deliver a long thin jet of fresh air which is directed generally parallel to the ceiling in which the tile is arranged so that room air is induced and/or entrained with the fresh air thereby to premix the fresh air with room air and minimise the amount of fresh air which enters into the occupied zone in the room at high velocity.

A nozzle 4 is shown in detail in figures 2 to 5. The nozzle includes an annular neck portion 6 which incorporates a pair of resilient tabs 8. The neck portion defines the air inlet of the nozzle. It is arranged to be received in a corresponding opening in face 10 of the tile 2 and the nozzle may be secured therein by urging it lo inwardly until a planar collar portion 12 abuts the face 10.

The nozzle 10 includes an arcuate side wall 14 which curves through an angle of greater than 180 and which extends downwardly in use. A lower wall 16 of the nozzle extends from the side wall 14. The lower wall includes first and second generally planar portions 18, 20 which slope downwardly from the side wall 14 at an angle of about 30 measured relative to the planar collar portion 12. The planar portions 18, 20 are generally mirror images of one another and are symmetrically arranged on opposite sides of a mirror plane defined across a diameter of the nozzle. The lower wall 16 includes an intermediate region 22 between planar portions 18, 20 which form a continuum with region 22. The intermediate region 22 curves inwardly when viewed from underneath (e.g. in the direction of arrow 24 shown in figure 4) to define a concave surface. More importantly, a convex surface 26 is defined within the nozzle. The convex surface may be slightly flattened in a central region. Also, an imaginary line extending centrally along the central region of the convex surface 26, generally diametrically across the nozzle, may extend generally parallel to a plane which includes the collar portion 12. The lower wall 16 is generally circular when viewed from below and suitably has a slightly wider diameter than the inner diameter of the neck portion 6. As will be seen from figure 4, the front edge of surface 30 of the lower wall within the nozzle includes a convex surface 26 interposed between two slightly concave or flat surfaces. The convex surface tapers inwardly on moving from an outer edge of the nozzle inwardly so the cross-sectional area bounded by lo the convex surface at its outer edge is greater (by a factor of at least one- third) than the cross-sectional area bounded by the convex surface at an end of the surface furthest away from the outer edge.

Also, it should be appreciated that the surface area of surface 30 (which incorporates planer portions 18, 20 and intermediate region 22) is greater than the area within the neck portion 6 which defines the inlet of the nozzle, due to the bulbous nature of the intermediate region 22.

This is believed to facilitate the formation of a long thin jet of air in use.

A nozzle as described has been tested and air flow patterns observed are shown in figures 6 and 7, wherein line 40 represents a ceiling tile in which a nozzle 4 is arranged. In the figures, the longer the arrows, the greater the air speed; the full arrows relate to air being delivered into the room; and the dotted arrows relate to room air induced towards the nozzle. It will be noted that as air flows out of the nozzle 10 a stream of room air is induced into the air flow and is entrained thereby.

As a result, room air pre-mixes with the air flow from the nozzle. Thereafter, the air may fall gradually as it cools to enter the occupied zone. If the nozzles were arranged to deliver air with a greater downwards component (as is the case with some known nozzles) or if there is no induction of room air into the air flow from the nozzle, the air from the nozzle would enter the occupied zone more quickly with the result that the temperature of air in the occupied zone would chance more quickly in a stepped fashion rather than the gradual temperature change which results from use of a nozzle 4.

In Figure 1, the nozzles 4 are shown all to be facing in the same direction. However, the orientation of the nozzles may be adjusted so that individual nozzles deliver air in any selected direction. In one embodiment, the nozzles may be arranged to set up a swirl effect, wherein the nozzles are rotated relative to an adjacent nozzle so - that outlet air form the nozzles combines to provide circular motion. This is illustrated in Figure 12 wherein the direction of the outlets of the nozzles 60 are represented by arrows from which it will be seen that each outlet is angled at 45 to each adjacent outlet. The central nozzle 60' may be a blank or arranged to direct air downwardly - 2s The linear diffuser 50 shown in Figures 8 and 9 comprises a rectangular neck 52 which is arranged to be releasably D secured in a ceiling using resilient tabs 8 so that a planar collar portion 54 abuts the ceiling. Side walls 56 and internal upstands 58 support lower wall 60 (which faces downwardly in use with the diffuser 50 secured in a ceiling). A front edge 62 of wall 60 extends substantially parallel to a side of the neck 52. However, in cross-section (Figure 9), the edge defines a wave shape of peaks and troughs. It will be appreciated that the cross- section of diffuser 50 is similar to that of the nozzle 4, particularly as shown in Figure 4. Thus, convex surfaces 26 are defined within the diffuser with concave surfaces 64 being defined therebetween. Consequently, the internal surface area of the lower wall 60 is greater than that defined by rectangular neck 52 which defines the inlet of the diffuser. The diffuser may deliver air as described above for nozzle 4.

The diffuser 80 of Figure 10 is similar to that of Figures 8 and 9 except that it includes back to back diffusers 60 which are arranged to deliver air in opposite directions.

The diffuser 90 of Figure 11 is also similar to that of Figures 8 and 9 except that it includes a staggered arrangement wherein spaced apart diffusers 60 face in one direction with diffusers 60' arranged therebetween facing in an opposite direction.

The diffusers described herein may be made out of plastics by injection moulding.

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each lo feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features

disclosed in this specification (including any

accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

1. A ventilation device for delivering air into a confined space, said device comprising: an inlet for air; an outlet for air; lo an air impingement surface positioned between the inlet and outlet and being arranged to be impinged by air entering the device via said inlet, said air impingement surface having a free edge which defines an edge of a lower part of the outlet, said free edge extending between a first point and a second point, wherein the length of the free edge is greater than the linear distance between said first and second points.

2. A device according to claim 1, wherein the ratio of the length of the free edge to the linear distance between said first and second points is at least 1.2.

3. A device according to claim 1 or claim 2, wherein said free edge includes at least one convex region.

4. A device according to claim 3, wherein said free edge includes first and second regions on opposite sides of said convex region.

5. A device according to claim 4, wherein said first and second regions are independently selected from straight and curved regions.

6. A device according to claim 5, wherein said first and second regions are curved.

7. A device according to any of claims 4 to 6, wherein said first and second regions are contiguous with said convex region.

8. A device according to any preceding claim, wherein said free edge is substantially symmetrical about a mirror lo plane which bisects the free edge.

9. A device according to any preceding claim, wherein said free edge includes a convex region which extends inwardly from said free edge across said air impingement surface thereby to define a convex area.

10. A device according to claim 9, wherein an underside of said air impingement surface which faces downwardly in use includes a concave area which corresponds to said convex area.

11. A device according to claim 9 or claim 10, wherein said convex area tapers inwardly on moving inwardly away from said free edge.

12. A device according to any of claims 9 to 11, wherein said convex area represents a bulbous projection from said air impingement surface which increases the area of said surface compared to a corresponding surface in the absence of said convex area.

13. A device according to any claim 9 to 12, wherein said convex area extends greater than 50% of the distance between said free edge (at an outermost point) and an opposite edge of the device directly opposite said outermost point of the free edge.

14. A device according to any preceding claim, wherein part of said air impingement surface slopes downwardly in use on moving from an outer edge of the device towards said free edge (at an outermost point).

lo

15. A device according to any preceding claim, wherein said device includes a free edge which includes a single convex region, optionally bounded by first and second regions.

16. A device according to claim 15, wherein said free edge appears convex when viewed in a first direction; and when viewed in a direction perpendicular to said first direction, said free edge is arcuate in shape.

17. A device according to claim 15 or claim 16, wherein said device is substantially circular in cross-section.

18. A device according to any preceding claim, wherein said inlet of said device is substantially circular in cross-section.

19. A device according to any of claims 1 to 14, wherein said device includes a free edge which includes a plurality of convex regions, optionally spaced apart by linear or curved regions.

20. A device according to claim 19, wherein said device is elongate and is preferably substantially rectangular in cross-section.

21. A device according to claim 19 or claim 20, wherein said inlet of the device is substantially rectangular in cross-section.

22. A device according to any preceding claim, wherein lo said air impingement surface has a surface area which is greater than the area of said inlet.

23. A device according to any preceding claim, wherein said device includes a spacer means arranged to space the air impingement surface from said inlet.

24. A device according to any preceding claim, which includes a lateral region which in use is arranged to abut a region outside an opening in which the device is arranged.

25. A device according to any preceding claim which is arranged in use for air to enter the device via said inlet in a first direction and to exit the device via said outlet in a second direction, wherein said second direction is transverse to said first direction.

26. A device according to any preceding claim, wherein said air impingement surface of the device is in a fixed, unadjustable position within the device.

27. An assembly comprising a plurality of ventilation devices according to any preceding claim.

28. An assembly according to claim 27, wherein said devices are arranged adjacent to one another, with each device being fed from the same air delivery device.

29. An assembly according to claim 28, wherein said plurality of devices are arranged in an array which includes at least ten devices.

lo

30. An assembly according to any of claims 27 to 29, wherein said array is configured such that a swirling air pattern is produced by a combination of air exiting from the devices in the array.

31. A method of delivery air in to a confined space wherein a ventilation device according to any of claims 1 to 26 is arranged in the space.

32. A device, an assembly and a method, each being independently substantially as hereinbefore described.