Air diffuser for high velocity hvac systems   

This invention relates to an air diffuser or vent of the type for use with high velocity HVAC systems.

A common shortcoming of air discharge vents or diffusers which are connected to high velocity air ducts as used in heating, ventilating, and air conditioning (HVAC) systems is, inter alia, the generation of unwanted air noise when attempting to dampen the speed of pressurized air at or near the point of discharge into an open space, such as a room. Prevost in U.S. Pat. No. 6,800,024 issued Oct. 5, 2004 discloses a damper arrangement when damping and diffusing air supplied from a HVAC high velocity system, which involves a termination receptacle or boot in the form of a cylindrical cannister attached to an air supply duct. The cannister at its upper or top end includes a supporting flange for attaching the cannister to a supporting framework, such as the underside of a floor. A cylindrical damper sleeve having a cutout in its bottom end and which is telescopically received within the cannister, is rotatable about its axis such that when aligned with the air inlet opening in the cannister, unobstructed pressurized air is permitted to enter into the cannister and which can be partially or fully shut off by causing the sleeve to rotate relative to the air inlet opening in the cannister. The sleeve which is attached to the vent plate is inserted through an aperture in a room facing, such as a ceiling, wall or floor and then into the cannister. Rotation of the vent plate also rotates the sleeve and its cut-out relative to the air inlet pipe to the cannister thereby controlling the rate of air flow into the cannister.

The novel air diffuser of this invention, like the air diffuser arrangement disclosed by Prevost, involves the use of a cannister, sleeve and diffuser cap or vent plate but which interact in a manner different from that taught by Prevost and which results in improved ease of installation and operation.

In accordance with this invention, the novel air diffuser which is designed to be attached to a air supply duct, comprises a cannister having a closed end and a open end, an air inlet pipe connected to an exterior sidewall of the cannister proximate its closed end for attachment to the air supply conduit and which is in air communication with an interior of the cannister. The cannister also includes attachment means proximate the open end of the cannister so that the cannister can be secured to a supporting frame, such as the underside of a floor or to a floor supporting joist, wall stud or the inside surface of wall or ceiling facing or sheathing material. A hollow sleeve having an open bottom end is slidingly insertable into the open end of the cannister and at its top end, is provided with a first array of air discharge ports. Co-operating means are located on an interior sidewall of the cannister and an exterior sidewall of the sleeve which permit the sleeve and the cannister to be telescoped together in a non-rotational relationship and which also enable the sleeve to be detachably connected to the cannister at selected one or more telescopic positions.

An air diffuser cap overlies and is connected to the top end of the sleeve and is provided with a second array of air discharge ports. Because the cap is also rotationally moveable relative to the sleeve, it can be moved from a first open position where the discharge ports of the first and second arrays are aligned for th free passage of air therethrough, and a second closed position where the air discharge passages of the first and second arrays are completely out of alignment and the passage of air therethrough is effectively blocked.

Since the spacing between the air diffuser cap which is normally located interior of a room on a wall, floor or ceiling facing, and which is also connected to the sleeve, relative to the open end of the cannister (located on the opposite side of the facing), can vary, and is usually a function of the thickness of the floor, wall or ceiling through which the sleeve extends, either the sleeve proximate its top end or the diffuser cap, is provided with abutment means which projects radially outwardly therefrom for engaging the room interior facing, such as the floor facing or the ceiling facing, to thereby limit the extent to which the sleeve can be telescopically inserted into the cannister and to render the cap effectively flush or substantially flush with the facing.

When the discharge ports of the first and second arrays are aligned in the first open position in order to maximize the passage of air therethrough, the ratio of this air exhaust opening to the air inlet pipe opening in the cannister is greater than 1:1 thereby relieving all back pressure within the cannister with an attendant reduction in air exhaust noise. Allowing the full volume of air to exhaust unrestricted into the room also allows for more even heating/cooling dispersion in the room and a more comfortable atmosphere.

While the cannister and sleeve can be of any complimentary cross-sectional form of construction e.g. rectangular or triangular, it is preferred that both be cylindrical in shape.

The co-operating means which permits the sleeve and the cannister to be telescoped together in a non-rotational relationship can include an elongate guide rail on one of the exterior side walls of the sleeve and an interior sidewall of said cannister and which is in sliding engagement with an elongate guide groove on the other of the exterior sidewall of the sleeve and interior sidewall of the cannister. Similarly, the co-operating means which enables the sleeve to be detachably connected to the cannister at a selected telescopic position, can include at least one row of spaced apart recesses in one of the exterior sidewalls of the sleeve and the interior of the cannister and a complimentary row or number of rows of spaced apart projections on the other of the exterior sidewall of the sleeve and interior sidewall of the cannister, whereby a fixed number of recesses detachably engage a corresponding number of projections when the cannister and the sleeve are at a desired telescopic position. Preferably, both the guide rail and the row of spaced apart recesses are located on the exterior sidewall of the sleeve.

Advantageously, and preferably when the sleeve and cannister are cylindrical in shape, the diffuser cap can include an annular skirt which is rotatably connected to the exterior sidewall of the sleeve proximate its top end. Since the sleeve does not rotate relative to the cannister, rotation of the diffuser cap relative to the sleeve causes the discharge ports in the first and second arrays, and which can be usually seen, to move between a fully open and fully closed position. Further, the abutment means which engages the sheathing or facing on the side opposite to the side where the cannister is located, can simply comprise an annular flange ring or disc which surrounds the diffuser cap.

In situations where the open bottom end of the sleeve, upon installation, could extend sufficiently far into the cannister so as to otherwise either fully or partially block the air inlet pipe, the sidewall of the sleeve adjacent the pipe opening can be notched or cut out, so that the opening is not obstructed by the sidewall of the sleeve, no matter what its relative telescopic position within the cannister may be.

In the accompanying drawings:

FIG. 1 is a perspective view of the air diffuser of this invention when in the assembled condition;

FIG. 2 is a perspective view of the cannister portion of the air diffuser;

FIGS. 3 and 4 are perspective views respectively of the air diffuser cap from its bottom end and the sleeve from its top end.

FIGS. 5 and 6 are similar perspective views to that of FIGS. 3 and 4 but wherein the abutment means is located on the sleeve rather than on the diffuser cap; and

FIG. 7 is an exploded perspective view of the relative positioning of the cannister located on one side of a facing, to the cap and its associated sleeve which extends through an aperture in the facing and into the cannister.

With reference to FIGS. 1, 2, 3, 4 and 7, the novel diffuser is constructed from three basic components, namely cylindrical cannister 200, cylindrical sleeve 300 and air diffuser cap 400.

As illustrated, cylindrical cannister 200 includes exterior sidewall 201, interior sidewall 202, bottom wall 203, mounting flange 204, attachment holes 205 and air inlet pipe 206 which is attached to an air supply duct or conduit (not shown) in a manner well known in the art.

Further, and best illustrated in FIG. 2, interior sidewall 202 of cannister 200 includes an elongate guide groove 207 and two opposed rows of recesses or notches, the function of which is explained in greater detail below.

Cylindrical sleeve 300 best seen in FIGS. 4, 6 and 7, is provided with an open bottom end 301 and a cylindrical exterior sidewall 303 having a cut-out or notch 305 its bottom end. The other top end 302 of sleeve 300 is provided with a first array of air discharge ports 304. Exterior sidewall 303 is provided with two rows of opposed and spaced apart projections 306, and guide rail 309.

In order to enable sleeve 300 to be slidingly and/or telescopically inserted into cannister 200, guide rail 309 on exterior wall 303 of sleeve 300 must be aligned with guide groove 207 on cannister 200. By aligning guide rail 309 with guide groove 207, the row of notches 208 provided in the interior sidewall 202 of cannister 200 are brought into alignment with the two rows of projections 306 located on the exterior sidewall 303 of sleeve 300. By virtue of this arrangement, sleeve 300, due to the interaction of guide rail 309 with guide groove 207, can only be telescoped within cannister 200 in a non-rotational manner. Further, and as the two parts are undergoing telescopic action, the two rows of projections 306 are permitted to detachably engage corresponding recesses in the two rows of recesses 208 in the interior sidewall 202 of cannister 200.

When cannister 200 and sleeve 300 are telescoped together at a desired location, it will be apparent that a fixed number of recesses in the interior sidewall 202 of the cannister engage in a detachable manner (upon pulling or pushing sleeve 300) a corresponding number of projections 306 in the exterior sidewall 303 of sleeve 300.

As cut-out 305 provided in sidewall 303 of sleeve 300 is effectively in line with air inlet pipe 206 of cannister 200, it will be evident that sleeve 300, even when fully inserted into cannister 200, does not in any way impede the flow of air into interior 202 of the cannister 200 from air inlet pipe 206.

As best seen with reference to FIGS. 3, 4 and 7, the free or top end 302 of sleeve 300, as mentioned earlier, is provided with a first array of air ducts 304. As illustrated in these figures, air diffuser cap 400 is provided with a second identical array of air discharge ports 401 which overlie the ports 304 of the first array located on the top end 302 of sleeve 300. Cap 400 is provided with annular skirt 403 which as shown, includes a pair of laterally opposed snap tangs 404 which are received in a corresponding pair of slots 308 in sidewall of sleeve 300. These tangs 404 which are engaged in snap engagement with slots 308 (only one being illustrated), due to the longitudinal extent of the slots, permit cap 400 to be rotated back and forth within the slots resulting in the opening and closing of second array of discharge ports 401 relative discharge ports 304 on sleeve 300 which are positioned therebelow.

As illustrated in FIGS. 3 and 7, cap 400 which is rotatably attached to sleeve 300 includes an annular flange 405 which, as best seen in FIG. 7, is designed to abutingly engage facing surface 501 of floor 500 when sleeve 300 is inserted through circular cut-out 503 and into the interior 202 of cannister 200. Since cap 400 is attached to sleeve 300, it will be apparent that ring 405 upon insertion of the sleeve into the cannister, will engage facing surface 501 of floor 500 and thereby limit the extent to which the sleeve can be inserted into the cannister. When in this position, the sleeve and cannister are held in position due to the interaction of the recesses in the cannister with the projections on the sleeve. Further, once in situ, the degree of air discharge from the cannister can be controlled from the facing side, merely by rotating cap 400 relative to non-rotational sleeve 300 since the first and second arrays are identical, and thus both sets of air discharge ports can be rendered fully opened or closed.

With particular reference to FIGS. 5 and 6, the diffuser cap and sleeve arrangement as illustrated therein can be contrasted with the cap and sleeve discussed earlier in connection with FIGS. 3, 4 and 7. As seen in FIG. 5, cap 400, while including skirt 403 and snap tangs 404, does not include the surrounding flange or ring 405 best illustrated in FIG. 3. Rather, a surrounding ring or flange 310 is provided proximate the top end 302 of sleeve 300. In this arrangement, the underside of flange 310 on skirt 300 is intended to engage a floor, wall or ceiling facing in the same manner that the underside of flange 405 of cap 400 seen in FIG. 7 is intended to engage facing 501 when the skirt 300 is inserted through aperture 503 from the facing side into cannister 200.