CA2896850C - Air diffuser - Google Patents

Abstract

An air diffuser for use with an air feed in a heating, ventilation, and air conditioning (HVAC) system, having a rotatable plenum from which project hollow blades. Each blade has an outlet port along the blade trailing edge, such that air received from an HVAC system flows through the air diffuser and is expelled from the outlet ports, causing the blades to rotate.

Description

AIR DIFFUSER
Cross Reference to Related Applications [0001] This application claims the benefit of US Provisional Patent Application No. 61/775,540, filed 23 January 2013.
Field of the Invention

[0002] The present invention relates to the field of HVAC (heating, ventilation, and air conditioning) and more particularly to ceiling air distribution/diffuser components.
Background of the Invention

[0003] There are many known devices for supplying and diffusing conditioned air in a building.

[0004] Over the years, traditional static diffusers have been utilized in ceilings to distribute conditioned air. The conventional approach is for these static diffusers to be hidden or to blend into the ceiling so as not to be noticed by the occupants of the building. There are numerous applications in which the traditional ceiling diffuser can be installed. Common installations include in a T-Bar, drywall and exposed ductwork.
The traditional static diffuser is connected to the ductwork of the building's air conditioning system.

[0005] Air diffusers associated with or incorporating rotatable fans are known.
For example, US Patent No. 5,795,220, Core, issued 18 August 1998; US Patent No.

6,030,287, Core, issued 29 February 2000; and US Patent No. 6,458,028, Snyder, issued 1 October 2002, disclose electrically driven fans mounted to, and aligned with, ceiling ducts. US Patent No. 4,598,632, Johnson, Ill, issued 8 July 1986, discloses an

7 PCT/CA2014/000051 air-driven ceiling fan wherein air flow through the duct work drives a squirrel cage blower connected by a shaft to the ceiling fan, such that a flow of air through the device sufficient to cause the squirrel cage blower to rotate, will also rotate the fan.
[0006] JP4370395 describes an air-driven ceiling fan wherein air provided by an air duct passes through a fixed strut supporting a rotatable fan, and thence to "blowout ports" in the fan blades, thus causing the fan to rotate. The drawing associated with the readily available English-language Abstract for JP4370395 shows an elongated "strut", providing a restricted passage between the air duct and the fan; and elongated ellipisoidal fan blades and "blowout ports".
Summary of the Invention [0007] In one aspect, the present invention provides an air driven ceiling fan configured to be installed in multiple ceiling applications with optional add-ons for such installations. The invention is meant to connect to new or existing ductwork that has been connected to an air delivery unit.

[0008] The air driven ceiling fan includes multiple hollow fan blades with a linear slot at the trailing edge of each blade. Each blade is attached to a plenum hub which in turn is connected to a duct collar that supports a shaft and bearing system to allow the plenum hub and blades to spin freely. The present invention provides both a ceiling fan and an air diffuser. Air being delivered to the air driven ceiling fan enters through the duct collar. From the duct collar, the air enters the plenum hub and thence into the blades. The air is then expelled through the slots in the trailing edge of the blade causing the hub and blades to rotate in a fan like motion.

[0009] In another aspect the present invention provides an air diffuser for use with an air feed in a heating, ventilation, and air conditioning (HVAC) system, the air feed having an air-feed cross-sectional area, the air diffuser include: a mount portion for mounting in association with an air feed, the mount portion having a mount portion interior for receiving air from the air feed and the mount portion interior having a mount portion interior cross-sectional area; a plenum, rotatably connected to the mount portion, and having a plenum interior for receiving air from the mount portion interior, the plenum interior having a plenum cross-sectional area equal to or greater than the mount portion interior cross-sectional area; and a plurality of blades projecting from the plenum, each blade having a discharge slot, with a discharge area, each of the discharge slots in fluid communication with the plenum interior, wherein the total area of all the discharge areas is between about 75% and about 95% of the mount portion interior cross-sectional area and wherein a flow of air out of the discharge slots tends to cause the plenum and blades to rotate relative to the mount portion.

[0010] The plurality of blades may consist of four blades.

[0011] The total area of all the discharge areas may be between about 80%
and about 90% of the mount portion interior cross-sectional area. The total area of all the discharge areas may be about 85% of the mount portion interior cross-sectional area.

[0012] The plenum cross-sectional area may be at least about 150% of the air-feed cross-sectional area. The plenum cross-sectional area may be between about 150% and about 225% of the mount portion interior cross-sectional area.

[0013] Each blade may include a planar upper wall, a planar lower wall, a curved leading edge and a planar trailing edge containing the discharge slot. The planar trailing edge and discharge slot may each have a length and the length of the discharge slot may be about 70% to 85% of the length of the planar trailing edge. The discharge slot may be centered along the length of the planar trailing edge. Each blade may have a proximal end adjacent the plenum and a distal end away from the plenum;
and in each blade, in terms of transition along the blade from the proximal to the distal end:
the planar upper wall the planar lower wall may converge towards each other;
the curved leading edge and the planar trailing edge may converge towards each other; and the discharge slot may narrow. The cross sectional area of each blade at the distal end may be about 20% to about 40% of the cross sectional area at the proximal end.

[0014] The air diffuser may also include an annular seal interposed between the mount portion and the plenum for impeding the release of air there between while permitting relative rotational movement as between the mount portion and the plenum.

[0015] The air diffuser may also include a stationary cap located adjacent the portion of the plenum opposite the mount portion.

[0016] The blades and plenum may include sheet metal.
Summary of the Drawings

[0017] Figure 1 is an exploded isometric view of a four-blade rotating hubcap air diffuser embodiment of the present invention.

[0018] Figure 2 is an isometric view of the embodiment of Figure 1.

[0019] Figure 3 is an elevation view of the embodiment of Figure 1..

[0020] Figure 4 is an exploded isometric view of a four-blade stationary-hubcap air diffuser embodiment of the present invention.

[0021] Figure 5 is a top plan view of a three-blade air diffuser embodiment of the present invention.

[0022] Figure 6 is an isometric view of a T-Bar ceiling support plate.

[0023] Figure 7 is an isometric view of a collared ceiling support plate.

[0024] Figure 8 an elevation view of the collared ceiling support plate shown in Figure 7.

[0025] Figure 9 is a top plan view of a four-blade air diffuser embodiment, (being either a four-blade rotating hubcap air diffuser embodiment or a four-blade stationary-hubcap air diffuser embodiment) shown to indicate the hub diameter dimension.

[0026] Figure 10 is a schematic representation of an end view of the inner end of a blade of the present invention, shown in operational orientation relative to the axis of rotation of the relevant air diffuser embodiment.

[0027] Figure 11 is a schematic representation of a side view of the blade of Figure 10, showing the trailing edge of the blade.

[0028] Figure 12 is a schematic representation of a top view of the blade of Figure 10.
Detailed Description with Reference to the Drawings

[0029] The air diffuser embodiments disclosed herein are described and shown as made from sheet metal and other metal components. However, to be clear, components of the air diffuser could readily be made from other suitable materials, for example plastics.

[0030] As shown in Figures 1 - 3, embodiments of the present invention include a four-blade rotating hubcap air diffuser 100.

[0031] As indicated in Figure 1, duct collar 112 (or mount portion) acts as the main support for the four-blade air diffuser 100. The main shaft support bracket 110 is configured to maintain the round shape of the duct collar 112. The main shaft support bracket 110 is fastened to the duct collar 112 with rivets. The main shaft support bracket 110 comprises two pieces between which the upper portion of the main shaft 114 is secured.

[0032] The main shaft 114 includes a shoulder 115 on the upper end of the main shaft 114 so as to impede downward movement of the main shaft 114 when the main shaft 114 is secured in the main shaft support bracket 110. The lower end of the main shaft 114 is a threaded end 116.

[0033] The main shaft 114 is preferably hardened steel, but alternate materials could be utilized to provide the same function for the air diffuser. The duct collar 112, main shaft support bracket 110, main shaft 114 and main shaft nut 144 are stationary components.

[0034] Upper thrust bearing assembly 117 and upper bushing 118 are mounted to the upper bushing mount 122 which is connected to upper hub 120. The upper bushing 118 is self aligning to support a radial load on the main shaft 114.

[0035] Lower thrust bearing assembly 146 and lower bushing 140 are mounted to the lower hub 138 utilizing the lower bushing mount 136. The lower bushing 140 is self aligning and supports a radial load on main shaft 114. Upper bushing 118 and lower bushing 140 keep the air diffuser centered on the main shaft 114.

[0036] Main hub 132 is interposed between upper hub 120 and lower hub 138.
The main shaft 114 and is fed through the relevant components and secured by the main shaft nut 144, which is attached to the threaded end 116 of the main shaft 114.
The lower hubcap 148 is fastened to the lower hub 138 to provide improved esthetics for the air diffuser. Although the current embodiment is shown with the lower hub cap 148 as a flat plate, other configurations could be used. As well, as described in greater detail in what follows, a stationary hubcap could be utilized when attached directly to the main shaft 114.

[0037] The main hub 132 includes blade ports 128, with each blade port having associated blade clip receivers 152 and a retainer screw hole 134.

[0038] Each blade 130 includes blade attachment clips 126 (riveted to the main body of the blade 130), a blade retainer tab 124 (having a hole there through), a blade end cap 150, and a longitudinally extending outlet slot 142 along the trailing edge of the blade 130.

[0039] Each blade 130 is mounted to the main hub 132 at a respective blade port 128 by inserting the blade attachment clips 126 into the blade clip receiver 152 and sliding the blade attachment clips 126 within the blade clip receiver 152 so as to bring them into interlocking engagement and so as to bring the hole in the blade retainer tab 124 into alignment with the retainer screw hole 134 for insertion of a retainer screw (not shown), thus securing the blade 130 to the main hub 132.

[0040] A stationary-hubcap air diffuser 200 embodiment is shown in Figure 4.
The components of the stationary-hubcap air diffuser 200 correspond to those in the four-blade rotating hubcap air diffuser 100 (as described above and shown in the drawings), except as follows. The stationary-hubcap air diffuser 200 includes a stationary hub cap 216 that is fixed, in that it does not rotate when the stationary-hubcap air diffuser 200 is in use, but rather remains stationary relative to the ceiling to which the stationary-hubcap air diffuser 200 is mounted.

[0041] In the stationary-hubcap air diffuser 200 shown in Figure 4, an upper sealed bearing 210 is fastened to the upper hub 120 and a lower sealed bearing is fastened to the lower hub 138. The main shaft 114 projects through both upper sealed bearing 210 and lower sealed bearing 212. The stationary hub cap 216 is fastened to the main shaft 114 by mating the stationary hub fastener 214 with the threaded end 116 of the main shaft 114.

[0042] The non-rotation of the stationary hub cap 216 enables the user to place images on the stationary hub cap 216, for example, business logos or trademarks, or decorative images. As well, useful features may be mounted to the stationary hub cap 316 (for example, a light or lights powered by electrical wiring running within a hollow main shaft (not shown)). Further, signs or decorative features may be hung from the stationary hub cap 216.

[0043] The above described embodiments have four blades. Other general blade configurations may be used, for example, a three-blade air diffuser 300 embodiment is shown in Figure 5. As with other general blade configurations, the three-blade air diffuser 300 may be a stationary-hubcap air diffuser or a rotating hubcap air diffuser, as the user desires. To be clear, embodiments with more than four blades may also be used.

[0044] In use, the air diffuser embodiments are connected to air feeds, being new or existing ductwork in HVAC systems. The air diffuser embodiments may be connected to exposed round ductwork by attaching the duct collar 112 directly to said ductwork.

[0045] Alternatively, with a T-Bar type ceiling, a ceiling plate 456 (shown in Figure 6), may be used as the terminal component of an air feed. In use, duct collar 112 is attached to the ceiling plate 456 utilizing the fastening tabs 460. The collar opening 458 is sized and configured to permit duct collar 112 to fit within the collar opening 458 so as to insert fasteners through fastening tabs 460 into duct collar 112.
Duct collar 112 may have pre-punched holes (not shown) for this purpose. Once the duct collar 112 is attached to the ceiling plate 456, the ceiling plate 456 can then be installed in the T-Bar grid. Ceiling plate 456 preferably includes seismic cable attachment 454 for use in connecting a support wire or cable for enhanced security of installation.

[0046] As a further installation alternative, an upper collar 462 (shown in Figures 7 and 8) may be suitable for a rigid ceiling installation (for example, a common drywall ceiling configuration or other hard surface ceiling installation). In use, upper collar 462 is typically fastened to new or existing ductwork with screws, at a location such that support bead 468 is positioned so as to hold ceiling ring 464 against or close to the ceiling. Lower collar 466 is sized and configured to accept duct collar 412 for attachment by screws or other suitable fasteners.

[0047] It will be apparent to a person skilled in the art that the mounting alternatives described above are merely examples of the many ways that the air diffuser could be connected to an HVAC system's ductwork.

[0048] In use, air flow is created from an air handling unit in a building.
The air flow is sent to designated areas in the building via main distribution ducting. Off of this main distribution ducting, multiple terminal ducts of various sizes channel air to areas engineered for optimal air distribution. An air diffuser embodiment would be attached to these terminal ducts to distribute the air provided to the air diffuser by the HVAC
system

[0049] In use, duct collar 112 allows air flow to pass through it. The air flow is then distributed to the plenum which is defined by the upper hub 120, main hub 132 and lower hub 138. As indicated in the drawings, the plenum has a larger diameter, and thus a larger plenum cross-sectional area, than the duct collar 112, which provides a chamber to calm the air and reduce the sound of the air flow before it enters each blade 130. This calming and noise reduction is accomplished by slowing the air flow without restricting the volume of flow, thus allowing the air flow to settle, mix and disperse evenly prior to entering blade ports 128 and blades 130, which facilitates a desirably even distribution of the air through the blade ports 128. The air that enters each blade 130, flows out of the outlet slot 142, which, if sufficient air flow is present to generate the required thrust, causes the blades 130 to rotate. In this way, the air diffuser embodiments act as a ceiling fan while at the same time, supplying conditioned air to the occupied space of a building. When the blades 130 are rotating, they draw air from above and pull it downward, mixing the above air with the conditioned air, thus producing a desired de-stratification of the air in the relevant area.

[0050] Figures 9 - 12 and the tables that follow are provided to illustrate the relative component dimensions of various embodiments (four blade and three blade) and sizes (8", 10" and 12" diameter duct collar), and other design aspects of the embodiments described herein.

[0051] An exemplary air diffuser 500 is represented in Figure 9 to illustrate the hub diameter 502. Additional angles and relative dimensions are illustrated in Figures through 11.

[0052] As shown in Figure 10, with respect to a notional blade proximal end 503, the additional angles include the angles of: 75 angle between the lower blade surface and a line parallel to the air diffuser axis of rotation 504; and 90 angle between the lower blade surface and the face of the blade trailing edge 506.

[0053] With respect to the notional blade proximal end 503 (Figure 10), the relative dimensions include: radius of curve of leading edge of blade 508;
thickness of trailing edge at blade proximal end 510; and distance from trailing edge to leading edge 512.

[0054] With respect to a notional blade trailing edge 513 (Figure 11), the relative dimensions include: thickness of trailing edge at blade proximal end 510;
thickness of trailing edge at blade distal end 516; radius of curve defining outlet slot proximal end 518; radius of curve defining outlet slot distal end 520; distance between center of curve defining outlet slot proximal end and center of curve defining outlet slot distal end 522;
and length of blade 524. It will be apparent that the size of each outlet slot 142 (such size referred to herein at times as the "discharge area") is defined by, and may be calculated from, the radius of curve defining outlet slot proximal end 518, the radius of curve defining outlet slot distal end 520 and the distance between center of curve defining outlet slot proximal end and center of curve defining outlet slot distal end 522.

[0055] With respect to a notional blade top surface 525 (Figure 12), the relative dimensions include: distance from trailing edge to leading edge 512; and width at blade distal end 528.

[0056] The following table sets out dimensions for the features identified above for four-blade air diffuser embodiments:
Reference 8" Duct Collar 10" Duct Collar 12" Duct Collar Number 502 12.00" 14.00" 16.00"
508 1.25" 1.50" 1.88"
510 2.50" 3.00" 3.50"
512 5.50" 6.50" 7.50"
516 1.00" 1.50" 2.00"
518 .38" .44" .56"
520 .22" .31" .38"
522 17.50" 21.75" 26.00"
524 24.00" 28.00" 32.00"
528 3.00" 4.25" 5.00

[0057] The following table sets out dimensions for the features identified above for three-blade air diffuser embodiments:
Reference 8" Duct Collar 10" Duct Collar 12" Duct Collar Number 502 12.00" 14.00" 16.00"
508 1.445" 1.75" 2.25"
510 2.88" 3.50" 4.50"
512 6.35" 7.50" 8.66"
516 1.15" 1.73" 2.31"
518 .50" .44" .56"
520 .30" .41" .50"
522 17.50" 21.75" 26.00"
524 24.00" 28.00" 32.00"
528 3.50" 4.91" 5.78"

[0058] As indicated in Figure 10, each blade 130 is fixed to the main hub with a 75 angle between the lower blade surface and a line parallel to the air diffuser axis of rotation 504. This general configuration has been found to provide a desirable aerodynamic flow across the blade 130. As well there is a 90 angle between the lower blade surface and the face of the blade trailing edge 506. It has been found that the 90 angle between the lower blade surface and the face of the blade trailing edge 506 in combination with the 75 angle between the lower blade surface and a line parallel to the air diffuser axis of rotation 504 tends to cause the air flow to pass through the outlet slot 142 at an angle to the air flowing over the blade 130 due to rotation, which assists in directing the air downward and outward from the following blade.

[0059] Each blade 130 is tapered. The taper contributes to sustaining the air velocity along the interior of the blade 130 so as to contribute to a balancing of the distribution of air flow and air velocity along the length of the outlet slot 142. The outlet slot 142 is also tapered, which also contributes to a balancing of the air velocity along the length of the outlet slot 142.

[0060] The above-described general configurations and embodiments have been found to provide a desirable functionality with respect to the usual range of volumetric flowrate (e.g. cubic feet per minute or cfm) found with conventional HVAC
systems.
However, different general blade 130 and blade port 128 configurations may be used.
It is understood that a usable functionality may be obtained, in terms of adequate thrust-induced rotation and introduction of conditioned air, if the total area of the outlet slots is in the range of about 75% to about 95% of the cross sectional area of the feeding duct, more preferably about 80% to about 90%, and still more preferably, about 85%.
It is also understood that a usable functionality may be obtained with different outlet slot locations and shapes. For example, an outlet slot located closer to the distal end of the blade might provide more rotational thrust though presumably such a configuration would increase air flow resistance.

Claims (14)

WHAT IS CLAIMED IS:

1. An air diffuser for use with an air feed in a heating, ventilation, and air conditioning (HVAC) system, the air feed for distributing air-handling-unit-created air flow and having an air-feed cross-sectional area, the air diffuser comprising:
a mount portion for mounting in association with an air feed, the mount portion having a mount portion interior for receiving the air-handling-unit-created air flow from the air feed and the mount portion interior having a mount portion interior cross-sectional area;
a plenum, rotatably connected to the mount portion, and having a plenum interior for receiving the air-handling-unit-created air flow from the mount portion interior, the plenum interior having a plenum cross-sectional area equal to or greater than the mount portion interior cross-sectional area; and a plurality of blades projecting from the plenum, each blade having a discharge slot, with a discharge area, each of the discharge slots in fluid communication with the plenum interior, wherein a total area of all the discharge areas is between about 75%
and about 95% of the mount portion interior cross-sectional area and wherein flow of the air-handling-unit-created air flow out of the discharge slots causes the plenum and blades to rotate relative to the mount portion.

2. The air diffuser of claim 1, wherein the plurality of blades consists of four blades.

3. The air diffuser of claim 1, wherein the total area of all the discharge areas is between about 80% and about 90% of the mount portion interior cross-sectional area.

4. The air diffuser of claim 1, wherein the total area of all the discharge areas is about 85% of the mount portion interior cross-sectional area.

5. The air diffuser of claim 1, wherein the plenum cross-sectional area is at least about 150% of the air-feed cross-sectional area.

6. The air diffuser of claim 1, wherein the plenum cross-sectional area is between about 150% and about 225% of the mount portion interior cross-sectional area.

7. The air diffuser of claim 1, wherein each blade comprises, a planar upper wall, a planar lower wall, a curved leading edge and a planar trailing edge containing the discharge slot.

8. The air diffuser of claim 7, wherein the planar trailing edge and discharge slot each have a length and the length of the discharge slot is about 70% to 85% of the length of the planar trailing edge.

9. The air diffuser of claim 8, wherein the discharge slot is centered along the length of the planar trailing edge.

10. The air diffuser of claim 7, wherein:
each blade has a proximal end adjacent the plenum and a distal end away from the plenum; and in each blade, in terms of transition along the blade from the proximal to the distal end:
the planar upper wall the planar lower wall converge towards each other;
the curved leading edge and the planar trailing edge converge towards each other; and the discharge slot narrows.

11. The air diffuser of claim 10, wherein the cross sectional area of each blade at the distal end is about 20% to about 40% of the cross sectional area at the proximal end.

12. The air diffuser of claim 1, further comprising an annular seal interposed between the mount portion and the plenum for impeding the release of air between the mount portion and the plenum while permitting relative rotational movement as between the mount portion and the plenum.

13. The air diffuser of claim 1 further comprising a stationary cap located adjacent the portion of the plenum opposite the mount portion.

14. The air diffuser of claim 1, wherein the blades and plenum comprise sheet metal.