GB2195758A - Air distribution apparatus - Google Patents

Abstract

To control the direction of air outflow from a longitudinal slot (15) in a housing, at least one angled strip or blade (20) is mounted on shaft (17) inside the housing so as to be slideable thereon transversely of the slot (15). Preferably a pair of independently movable strips or blades (20) are symmetrically arranged on the shaft. <IMAGE>

Description

SPECIFICATION Air distribution apparatus This invention relates to air distribution apparatus, commonly known as a slot diffuser, which is designed as an outlet device for an air conditioning system.

A plurality of such slot diffusers are usually installed in the ceiling of a room which is to be supplied by conditioned air, at the outlet end of a relevant air supply passageway. A variety of slot diffuser constructions have been previously proposed. Basically, each comprises a housing having at least one air outlet aperture in a wall thereof and one or more air pattern control elements and/or dampers which are mounted within the housing and serve, respectively, to control the direction of air flow out of the aperture and to shut off the air flow completely, if need be. In the majority of known slot diffusers, these control elements or dampers are in the form of swingable flaps the positions of which can be readily adjusted at the time of installation.

It is an object of the present invention to provide a novel and alternative design of slot diffuser, which is at least equally effective in operation compared to previousiy known diffuser designs.

Pursuant hereto, the invention provides air distribution apparatus comprising a housing having an air outlet aperture in the form of a longitudinal slot in a wall thereof and, inside the housing, an air pattern control element in the form of an angled strip or blade which is slidably mounted on a shaft so as to be movable from side to side transversely of the slot.

Preferably two such elements are mounted inside the housing and are independently slidable on a common shaft. Moreover, in a most advantageous arrangement the two elements are mounted as a symmetric pair so as to have respective first limbs which can be moved into mutual contact or moved apart in generally parallel disposition and respective second limbs which diverge outwardly in mutually opposing directions.

Alternatively, however, an individual pattern control element with a Y-shaped or inverted Y-shaped profile may be provided, or else a pair of elements of the type mentioned in the preceding paragraph may be connected together for movement as a unit.

A damper in the form of a flat plate may conveniently be provided for sliding into position at the side of the pattern control element(s) remote from the outlet aperture whenever it is desired to completely shut off the flow of air via the aperture. The housing is preferably provided with a pair of opposing slots, channels or grooves for reception of the edges of the damper.

The invention will be described further, by way of example, with reference to the accompanying drawings, in which: Figure 1 is an end view of a preferred embodiment of a two-slot diffuser in accordance with the present invention; Figures (2a) to (e) illustrate a range of positions for the air pattern control elements of the diffuser shown in Fig. 1; Figure 3 is a reduced scale cross-section, illustrating the diffuser shown in Fig. 1 attached to a plenum chamber in a first manner; Figure 4 is a view similar to Fig. 3 illustrating the same diffuser attached to a different plenum chamber in a different manner; and Figure 5 is an enlarged cross-section of a single air pattern control element of the diffuser shown in the preceding Figures.

With reference to Fig. 1, a preferred embodiment of a two-slot diffuser in accordance with the invention comprises an elongate housing consisting of a pair of generally parallel opposing side walls 11, 12 with a parallel intermediate wall 13 located midway therebetween, and a front wall 14 which is provided with two longitudinal outlet apertures or slots 15. A respective air chamber 16 is defined between the intermediate wall 13 and each of the side walls 11, 12, and a respective one of the slots 1 5 is disposed centrally at the front of each chamber 16. The walls 11, 12, 13 are connected and fixed relative to each other by a plurality of shafts 17 which extend perpendicular to the walls at regular intervals along the length of the housing.

These shafts 1 7 extend through aligned holes in the walls 11, 12, 13 and the ends thereof are secured by washers and nuts 18. Each shaft preferably consists of a steel rod surrounded by a nylon sleeve.

In each chamber 16, a pair of air pattern control elements in the form of angled blades or strips 20 are slidably mounted on the shafts 17 in symmetrical disposition. Each blade 20 is angled so as to have two limbs, the first limbs 21 being arranged approximately vertically and seated on the shafts 17 so that they can be moved into mutual contact (as in Fig. 1) or moved apart in general parallel disposition (see Fig. 2(e)), and the second limbs 22 diverging outwardly in mutually opposing directions.

The housing walls 11, 12, 13 and the blades 20 are formed as extruded aluminium profiles.

In use, the diffuser housing is installed in a ceiling and is fitted to the outlet end of a plenum chamber 30, either by way of a bracket 31 or by the edges of the plenum chamber 30 being received into upwardly open channels 32 formed on the outer surfaces of the respective side walls 11, 12 of the housing, as shown in Figs. 3 and 4 respectively. Air is then supplied to the space below the ceiling by way of the plenum chamber 30 and the slot diffuser. The direction of the air flowing into that space is controlled by the positions of the elements 20 and the most common positions likely to be used are shown diagrammatically in Figs. 2 (a) to (e).

In the position shown in Fig. 2(a) the blades 20 of each pair (i.e. the two blades 20 in each of the two chambers 16) are closed together so that their first limbs 21 are in abutment. Moreover, they have been slid along the shafts 17 as far as possible in one direction (to the right in Fig. 2(a)) so that in the right hand chamber 16 the second limb 22 of the right hand blade 20 contacts the side wall 12, whilst in the left hand chamber 16; the second limb 22 of the right hand blade 20 contacts the intermediate wall 13. The air is thus deflected around the respective left hand blades 20 and flows out of the apertures 15 obliquely towards the right, as indicated by the arrows, giving a generally horizontal air pattern. Obviously, to achieve a similar air flow pattern in the opposite direction, the pairs of blades 20 are simply slid to their extreme left hand position.

The blade position shown in Fig. 2(b) differs from that shown in Fig. 2(a) since in this case the blades 20 are slid to the extreme left-hand side in the left hand chamber 16 and to the extreme right hand side in the right hand chamber. Thus air issues obliquely horizontally to the left from the left hand chamber 16 and obliquely horizontally to the right from the right hand chamber 16 i.e. there is a diverging air flow pattern.

In the position shown in Fig. 2(d), the blades 20 of each pair are still in abutment, but in this case they are located centrally within each chamber 1 6 so the resultant air flow from the apertures 15 is vertically downwards. It should, be noted however, that at each side of each slot 1 5 the inner surface of the front wall 14 is in the form of a wedgeshaped projection 19 tapering towards the respective edge of the slot 15, and these projections 19 contribute to local deflection of the air flow from each slot 15.

The position of the blades 20 shown in Fig.

2(c) is intermediate the positions indicated in Figs. 2(b) and 2(d) and the resultant air flow is divergent, but to a lower degree than with the Fig. 2(b) blade position.

Finally, in the position shown in Fig. 2(e), the blades 20 of each pair are separated and slid to opposing sides of each chamber 16.

This arrangement could be used as an alternative to the Fig. 2(d) position to achieve a vertically downward air flow into the space beneath the diffuser. It is envisaged, however, that the blades 20 will probably only be displaced into this arrangement when access is required to fixing screws 33 which are used to connect the bracket 31 to cross-pieces 34 mounted at the rear of the chambers 16, for example during installation of the diffuser. In this respect, the height of the diffuser relative to the plenum chamber 30 can be adjusted by screwing the screws 33 through the bracket 31 to a greater or lesser extent.

Incidentally, the position of the blades 20 as well as the height of the housing is generally settled at the time of installation of the diffuser. However, later adjustment of same is not precluded. The provision of the sleeves of nylon on the shafts 17 facilitates the sliding of the blades therealong, so manual adjustment is quite easy. Moreover, Fig. 5 shows a preferred form of the blade 20 in which the oblique, frontwardly facing surface of the second limb 22 is provided with shoulders 23 at each end to allow for insertion of some for of tool to push the blade 20 to and fro along the shafts 17 to its desired position.

Opposing channels 35 are provided on the walls 11, 12, 13 of the diffuser, facing inwardly of the respective chambers 16, either for reception of the ends of the cross-pieces 34 (for mounting the bracket 31 and, thus, attachment to the plenum chamber 30, as mentioned above), or for reception of the edges of a damper, in the form of one or more sliding plates, which may be inserted in each chamber 16 to the rear of the elements 20 to completely shut off air flow therethrough.

A pair of projections 36 defining a channel of circular cross section is provided on the outside of each side wall 11, 12, close to the front wall 14 of the housing. This channel is available for insertion of screws into its end regions to facilitate the attachment of an end plate to the diffuser and/or the mounting of the diffuser into a ceiling.

Respective pairs of downwardly and upwardly directed channels 37, 38 are also provided on the chamber facing surface of each housing wall 11, 12, 13. These are to accommodate the ends of plates or angle pieces which are used to align and connect together (end to end) adjacent lengths of slot diffuser.

The invention is, of course, not limited to the exact details of the above described embodiment, which is merely a preferred example. It will firstly, for example, be appreciated that any number of air chambers from one to ten or more, (and a corresponding number of air outlet slots), may be included in the diffuser either by omitting the intermediate wall or providing an appropriate number of intermediate walls between the opposing side walls. Also the blades of each pair may be connected, back to back, so they cannot be separated, or they may be integrally formed as a single Y-profiled or inverted Y-profiled element. Alternatively, only a single, larger angled blade, similar in configuration to each of those in the illustrated example, may be provided in each air chamber. In further embodiments, however, the form of the angled air pattern control elements may be completely different from those described.

Many other variations in minor details of configuration of the walls are possible.

Claims (9)

1. Air distribution apparatus comprising a housing having an air outlet aperture in the form of a longitudinal slot in a wall thereof and, inside the housing, an air pattern control element in the form of an angled strip or blade which is slidably mounted on a shaft so as to be movable from side to side transversely of the slot.

2. Apparatus as claimed in claim 1 wherein two air pattern control elements are mounted inside the housing and are independently slidable on a common shaft.

3. Apparatus as claimed in claim 2 wherein the two elements are mounted as a symmetric pair so as to have respective first limbs which can be moved into mutual contact or moved apart in generally parallel disposition and respective second limbs which diverge outwardly in mutually opposing directions.

4. Apparatus as claimed in claim 1 wherein an individual air pattern control element having a Y-shaped or inverted Y-shaped profile is mounted inside the housing.

5. Apparatus as claimed in claim 1 wherein two air pattern control elements are mounted inside the housing as a symmetric pair having respective first limbs in generally parallel disposition and respective second limbs which diverge outwardly in mutually opposite directions, the first limbs being connected together so that the two elements are movable as a unit.

6. Apparatus as claimed in any preceding claim wherein a damper in the form of a flat plate is provided for sliding into position at the side of the pattern control element(s) remote from the outlet aperture.

7. Apparatus as claimed in claim 6 wherein the housing is provided with a pair of opposing slots, channels or grooves for reception of the edges of the damper.

8. Apparatus as claimed in any preceding claim wherein wedge-shaped projections tapering towards the slot are provided inside the housing to contribute to local air deflection.

9. Air distribution apparatus substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.