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:
With reference to
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
Cylindrical sleeve 300 best seen in
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.
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As illustrated in
With particular reference to