Air Diffuser

Abstract

Wall means define a generally elongated, narrow air passage having an air discharge aperture extending substantially the full length of the elongated air passage and an air inlet located generally centrally of the elongated dimension of the air passage. A baffle or air deflecting means, disposed within the air passage opposite the mouth of the air inlet, is shaped so as to direct air entering the air passage in both directions along the elongated dimension of the air passage. Preferably the diffuser is equipped with adjustable shutter means mounted within the air passage and engageable with the air inlet so as to control the volume of air moving into the air passage from the air supply.

Description

BACKGROUND OF THE INVENTION

The present invention relates to air diffusers and more particularly to air diffusers for use with light troffers and perimeter air induction systems.

It has become accepted practice in the commercial building industry to integrate overhead air handling and lighting systems into a single unit. The use of such integrated systems provides an aesthetically pleasing appearance inasmuch as it reduces the number of outlets and fixtures in the ceiling. Another advantage realized from such systems is the reduced cost of installation since only a single opening need be cut in the ceiling for the combined light-air unit.

The use of these integrated air handling troffers, as they are commonly known, does pose some problems. One of the problems in the use of such integrated systems is that they are normally installed in commercial buildings wherein false or drop ceilings are employed. In such ceilings, of course the space available in the areas both above and on the sides of the fixture is limited. The design of an efficient air diffuser presents certain difficulties which, to mention a few, include ensuring that an adequate supply of air enters the air passage, providing means to permit convenient adjustment of the air flow being discharged from the air passage and ensuring that unwanted drafts are not allowed which would cause discomfort to the occupants of the room. It is therefore clear that the design of the plenum chamber or air passage is quite critical, it being desirable that the plenum chamber fit as snugly as possible onto the chassis of the troffer and still be an efficient air distributor.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide an improved air diffuser for use with a light troffer.

Another object of the present invention is to provide an improved air diffuser for use with a light troffer in which the volume of air flow into the unit can be easily adjusted.

Yet another object of the present invention is to provide an air diffuser for use with a light troffer which provides improved distribution of air flow.

Still another object of the present invention is to provide an improved air diffuser for use with a light troffer in which the direction of air flow exiting from the diffuser can be readily adjusted.

Another object of the present invention is to provide an air diffuser for use in a perimeter air induction system.

These and other objects, advantages and features which will become apparent from the attached drawings, the description given herein and the appended claims are provided by the present invention.

The air diffuser herein comprises a suitable wall means which defines an elongated, generally narrow air passage. Located centrally of the elongated dimension of the elongated air passage is an air inlet through which incoming air passes. An elongated air discharge aperture extends substantially the full length of the elongated air passage. A baffle or air deflecting means is so disposed within the air passage and has a shape such that air entering the air passage and impinging upon the baffle is directed longitudinally towards the ends of the air passage. Preferably, an adjustable shutter means is mounted within the air passage. The shutter means, which is engageable with the air inlet, serves to control the volume of air entering the air passage.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of the air diffuser of the present invention.

FIG. 2 is a cross-sectional view taken along the line 2--2 of FIG. 1.

FIG. 3a is a cross-sectional view taken along the line 3--3 of FIG. 2.

FIG. 3b is a view similar to FIG. 3a showing another form of baffle.

FIG. 4 is a cross-sectional view taken along the line 4--4 of FIG. 2.

FIG. 5 is a view similar to FIG. 4 showing a modification of the air passage design of the air diffuser.

FIG. 6 is an enlarged isometric view of the baffle shown in FIG. 3b.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the Figures, the air diffuser is seen to comprise an elongated stepped side wall 10, an elongated, substantially flat side wall 11 (best seen in FIG. 3a), a pair of end walls 12 and 13, respectively, and an elongated top wall 14. While end walls 12 and 13 are shown as having a lower substantially vertical section and an upper inwardly inclined section, walls 12 and 13 can of course be planar, outwardly inclined, concave, etc. Stepped side wall 10 is comprised of an upper vertical section 15, a lower vertical section 16 and a laterally extending section or shelf 17, the opposite edges of which are connected to upper and lower vertical sections 15 and 16, respectively. Walls 10, 11, 12, 13 and 14 define a generally elongated, narrow air passage 18. A circular air inlet 19 is located generally centrally of the ends of stepped wall 10 and communicates with air passage 18. A collar 20 extending from stepped side wall 10 allows an air supply conduit 21 (shown in phantom lines) to be easily connected to the air diffuser. Lower vertical section 16, together with the lowermost portions of walls 11, 12 and 13 serve to define an elongated air discharge aperture 22 which extends substantially the full length of the air diffuser. As best seen in FIGS. 1 and 4, lower vertical section 16 and the lowermost portion of side wall 11 have inwardly extending flange portions 23 and 24, respectively which serve to constrict the mouth of the air discharge aperture 22.

Mounted within air passage 18 is a V-shaped baffle 25 having inclined legs 26 and 27 joined together at an apex 28. Baffle 25 is secured within air passage 18 by means of flanges 29 and 30 extending from the free ends of legs 26 and 27, flanges 29 and 30 being secured to wall 11 by welding or some other suitable means of fastening. As seen particularly in FIG. 3a, baffle 25 is mounted within air passage 18 such that the apex 28 is in close proximity to air inlet 19. Thus when air passing via inlet 19 into air passage 18 impinges upon the inclined legs 26 and 27 of baffle 25, it is diverted toward respective ends of the passage 18, i.e., towards end walls 12 and 13, respectively. Flow arrows in FIG. 3a clearly depict the air flow pattern described above.

Also disposed within air passage 18 are adjustable shutters 31 and 32 which are engageable with air inlet 19. A bolt 33 extends through a slot 34 in vertical section 15 of stepped wall 10 and screws into a threaded hole in shutter 31. A spring 35 biased between the head of bolt 33 and a washer 36 resiliently urges shutter 31 against the inside surface of upper vertical section 15 of stepped wall 10. By adjusting screw 33, the frictional contact between shutter 31 and vertical section 15 can be increased or decreased as desired. By like means, shutter 32 is slidably mounted within air passage 18, bolt 37 extending through slot 38 and spring 39 being biased between the head of bolt 37 and washer 40. To slide either shutter 31 or 32 so as to increase or decrease the volume of air entering passage 18, it is only necessary to insert a rod or the like through air discharge aperture 22 and move the shutter in the desired direction. Thus it is seen that the volume of air entering the room being ventilated can easily be controlled from below the ceiling with relative ease. Although not necessary, generally each of shutters 31 and 32 will be disposed so as to engage approximately one-half of the area of inlet 19 whereby if both shutters 31 and 32 are moved to a closed position, i.e., towards one another, substantially no air will enter air passage 18 through inlet 19. Also, as will be readily recognized, the unique dual shutter system provided herein allows one side of the air diffuser to be shut off while the other side is at substantially full volume. It is to be understood that the method of slidably mounting shutters 31 and 32 in air passage 18 is merely one illustration of numerous methods that can be utilized. It is only necessary that shutters 31 and 32 be adjustable so that the volume of air entering passage 18 be controllable.

Shutters 31 and 32 are also provided with deflector plates 41 and 42 respectively. Deflector plates 41 and 42 which may be integral with shutters 31 and 32 or separate parts fastened thereto by some suitable means serve to divert air moving through air passage 18 in a generally downwardly direction towards air discharge aperture 22. Naturally the exact design of deflectors 41 and 42 can vary depending on the air distribution sought. For example, deflectors 41 and 42 can be substantially the same width as air chamber 18 as determined by the distance between walls 11 and 15 or as shown in the drawings, can be less than the width of air chamber 18 between wall 11 and 15. Furthermore, it is not necessary that deflectors 41 and 42 be employed at all.

As best seen in FIGS. 4 and 5, the air diffuser is equipped with an air discharge pattern control means comprising a vane plate 43 which extends substantially the full length of air passage 18. Vane plate 43 is a shallow generally V-shaped member having legs of unequal length, the shortest leg of vane plate 43 being secured to the inside surface of vertical section 16 of stepped wall 10, the longer leg of vane plate 43 extending into air passage 18 such that air leaving air passage 18 and striking the inwardly facing surface will be directed toward the lower part of side wall 11 adjacent air discharge aperture 22. Thus, air which passes through air discharge aperture 22 is diverted laterally outward by its impingement upon the upper surface of flange 24 at air discharge aperture 22. As is seen in FIG. 4 in the phantom lines, vane 43 may be positioned on either of side walls 10 or 11 depending on which direction it is desired to laterally divert the air flow. While vane 43 is shown as a rigid member, it can be a hinged member which can be continuously adjusted from a full vertical position, i.e., forming no impediment to air flow through air discharge aperture 22, or to a position such as shown in FIG. 4 where considerable diversion of the air flow out of air discharge aperture 22 is accomplished. Lastly, as will be apparent, vane 43 may be dispensed with entirely if it is desired to allow direct vertical flow of the air out of air discharge aperture 22. Nonetheless, the use of vane plate 43 or some such similar device provides an easy means of predirecting the air flow out of aperture 22.

As should also be noted in conjunction with the use of the vane 43, flanges 23 and 24 may be dispensed with if desired, it being preferred that at least one be used when vein 43 is employed so as to allow lateral diversion of the air flow as it exits through air discharge aperture 22. The position of vane plate 43 determines which of flanges 23 or 24 is needed. If vane plate 43 is attached as shown in FIG. 4, flange 24 is used whereas if vane plate 43 is attached as shown in the phantom lines in FIG. 4, flange 23 is needed.

In FIGS. 3b and 6, a modified form of baffle is shown. Baffle 44 is substantially V-shaped on one end having inclined legs 45 and 46 attached to flange portions 47 and 48. Flange portions 47 and 48 furnish a means to secure baffle 44 to wall 11 of the air diffuser. As best seen in FIG. 6, baffle 44 tapers from one end to the other such that it is V-shaped on one end as explained above, substantially flat at the opposing end and substantially trapezoidal in shape having a flat top 49 when viewed in transverse cross-section intermediate of the substantially flat end and the V-shaped end. As will be apparent from a comparison of baffles 25 and 44, the use of baffle 44 does not result in all of the air being divided and diverted towards opposite ends of air passage 18 as does the use of baffle 25. Nonetheless, baffle 44 does serve to divert at least a portion of the incoming air to respective ends of the air passage 18. In general, the precise shape of the baffle means is not critical provided it is shaped so that at least a portion of the air entering air chamber 18 is diverted towards the respective ends of air chamber 18. Thus, for example, the baffle could be a channel-shaped member having a flat-top surface adjacent the air inlet and outwardly sloping legs which were fastened to the other side wall of the air diffuser. Such a baffle would have a trapezoidal-shape when viewed in transverse cross-section. Likewise, the baffle could have an arcuate, oval, circular or other such shaped surface, the only requirement being that the baffle serves to distribute the air towards respective ends of the air passage.

As will be evident from the foregoing, while the air passage formed by the wall means will be generally of an elongated and narrow shape, its precise shape is not critical. For this reason, various combinations of wall means can be employed depending on the desired configuration of the air passage sought. FIG. 5 shows one modification of the air diffuser herein wherein side walls 50 and 51 are substantially flat being connected at their upper edges to top wall 52. In the modification of the air diffuser shown in FIG. 5, deflector 53 is not rectangular as is deflector 41 but has a generally trapezoidal-shape to accommodate the generally trapezoidal cross-section of air chamber 18 formed by walls 50, 51 and 52. Whatever the precise cross-sectional shape of air passage 18, it is preferable that the width of air passage 18 as determined by the distance between the elongated side walls be greater at the top, i.e., closest the air inlet, than at the bottom, i.e., closest the air discharge aperture.

While as shown above, air inlet 19 is a generally circular opening in one of the side walls, it is not necessary that the inlet be circular. Air inlet can be oval, square, triangular or virtually any other shape which is desired. As a practical matter, the use of a circular opening provided with an annular collar makes for a convenient means for attaching an air supply conduit to the air diffuser. Although inlet 19 is shown as being in one of the side walls, it can be in the top wall if desired so long as it is located somewhat centrally of the elongated dimension of the air passage.

As shown above, the air diffuser makes use of dual adjustable shutter means mounted within the air chamber. It is to be understood however, that the use of a single adjustable shutter is within the scope of the present invention. Such a single adjustable shutter could be mounted on either side of the air inlet and would serve to control the volume of air entering one side of the air diffuser rather than having the volume controlled on both sides of the diffuser as when two adjustable shutters are employed. Here again, it is not necessary that the air diffuser be provided with any adjustable shutter means if it is desired to have a fixed volume of air entering the diffuser through the air inlet at all times.

While the air diffuser of the present invention has been described with particular reference to its use with a light troffer, it is to be understood that the adaptability of the air diffuser is not so limited. For example, as stated earlier, the air diffuser is ideally suited for incorporation into perimeter air induction systems. In newer commercial buildings, the ceiling construction generally consists of horizontally disposed members which support ceiling panels and the lighting fixtures and air conditioning such as the air handling light troffers described above. In such ceiling designs, it is the normal practice to install a perimeter member which, runs along the edge of the ceiling adjacent a wall. These perimeter members when properly designed having apertures therein can be used as a grid for an air conditioning outlet. By discharging air into the room or building immediately adjacent an outside wall carrying window, it is possible to neutralize the effect of the radiated heat at its source. However, in order to use such a perimeter air induction system, it is necessary that the air diffuser be of a design such that it fits in the quite limited space above the member. The air diffuser described above is well-adapted to such an installation being both compact enough to fit conveniently and yet be an efficient air distributor means.

Claims

I claim:

1. An air diffuser comprising wall means defining an elongated air passage, said wall means including a first elongated side wall, a second elongated side wall, an elongated top wall, a first end wall and a second end wall, lowermost sections of said side walls defining an elongated air discharge aperture, said elongated air discharge aperture running substantially the full length of the elongated dimension of said air passage, said air passage between said side walls adjacent said air discharge aperture being less than the width of said air passage between said side walls adjacent said top wall, said air passage having an air inlet located in said first side wall generally centrally of the elongated dimension of said elongated air passage such that air supplied to said diffuser is fed directly into said air passage,

baffle means disposed substantially wholly within said air passage, said baffle means being mounted on said second side wall and disposed generally opposite said air inlet, said baffle means having a shape such that at least a portion of the air entering said air passage and impinging on said baffle means is directed longitudinally towards respective ends of said air passage,

adjustable, sliding shutter means mounted within said air passage, said shutter means being engageable with said air inlet whereby the volume of air entering said air passage may be controlled,

air discharge pattern control means disposed in said air passage adjacent said air discharge aperture whereby air exiting through said air discharge aperture may be pre-directed.

2. The air diffuser of claim 1 wherein there are two adjustable shutter means, said shutter means being mounted on opposite sides of said air inlet, each of said shutter means being engageable with generally one half of said air inlet.

3. The air diffuser of claim 1 wherein said adjustable shutter means includes air deflector means for directing air moving through said air passage towards said air discharge aperture.

4. The air diffuser of claim 1 wherein said first side wall is stepped and said second side wall is substantially flat, said stepped side wall being defined by an upper vertical section, a lower vertical section and a substantially laterally extending shelf, the opposite lateral edges of which are connected to said upper and lower vertical sections, said lower vertical section of said stepped wall, the lower portions of said end walls and the lower portion of said second side wall defining said air discharge aperture.

5. The air diffuser of claim 1 wherein said first side wall is substantially flat and said second side wall is substantially flat.

6. The air diffuser of claim 4 wherein said air discharge pattern control means is attached to one of said side walls and the lower edge of the other side wall adjacent said air discharge aperture has an inwardly extending flange serving to constrict the mouth of said air discharge aperture.

7. The air diffuser of claim 5 wherein said air discharge pattern control means is attached to one of said side walls and the lower edge of the other side wall adjacent said air discharge aperture has an inwardly extending flange serving to constrict the mouth of said air discharge aperture.

8. The air diffuser of claim 1 wherein said baffle means comprises a V-shaped member, said V-shaped member being mounted in said air passage on said second side wall such that the apex of said V-shaped member faces and closely approaches said air inlet, the apex of said V-shaped member being aligned generally centrally with said air inlet, the inclined legs of said V-shaped member serving to deflect air entering said air passage toward said end walls.