Patent Application
20120302152
1. Technical Field
The present invention is directed toward air pattern controllers for controlling the direction and velocity of air flow from a diffuser into a room. In particular, the present invention is directed toward a universal air pattern controller for use in air slot diffusers of any shape, including curved applications.
2. Prior Art
Air distribution devices, also referred to as diffusers, are typically set into a ceiling or other walls in a room and receive conditioned air along their length from a supply duct. Slot diffusers have elongate, narrow slots, each of which is open across its full width and enclosed by a frame. In order to successfully supply air into an occupied space, an air supply system must deliver air from suitable locations, in appropriate volumes, in proper directions, and at correct velocities. Except in very high-ceilinged spaces, the proper direction for air emitted from the diffuser is in a tight, horizontal pattern closely hugging the ceiling of the occupied space. The primary means for effecting such a horizontal pattern in a slot diffuser is through an air pattern controller within the slot diffuser approximately at or adjacent to the plane of the ceiling undersurface, which deflects the air across the ceiling.
Slot diffusers are used in many different environments for introducing heated or cooled air flow into an occupied space, and are frequently used to satisfy architectural concepts that require continuous length applications without compromising air distribution performance. Conventional slot diffusers are generally either linear or curved, though the configurations can present other specialized shapes.
In some applications, it is desirable to provide a high velocity air stream from one or more air slots that flows generally perpendicularly into the room relative to the face of the diffuser. In other applications, it is desirable to direct one or more air streams in other directions relative to the face of the diffuser into the room. Air pattern controllers contribute to the performance of a slot diffuser, and preferably provide a range of air pattern adjustments.
One conventional air pattern controller typically used in conjunction with a linear slot diffuser is the axial adjustable, or “ice-tong,” pattern controller. Ice-tong air pattern controllers are assembled extrusions typically constructed with two separate curved vanes pivotally mounted at a top end on a vertical member such that each of the respective vanes pivots in an opposite direction away from the vertical member. The hinge point at which the two vanes are connected permits a user to direct two points on a bottom or working end of the vanes to create a desired angle, or to contact a side wall. The positioning of the vanes in either opposite directions or the same direction dictates the direction of the air flow from the corresponding air slot. Alternatively, pivoting one or both vanes such that the working end of the vane contacts a side wall can completely obstruct the flow of air from the air slot. Examples of this conventional type of air pattern controller can be seen in the PTBA series plenum linear slot diffusers made by the Krueger Manufacturing Company, and in the ML series linear slot diffusers made by The Titus Company. Ice-tong pattern controllers allow for simple adjustment in the direction and volume of the air flow
Although it is standard practice in the HVAC industry to provide pattern-adjustable linear slot diffusers that utilize ice-tong pattern controllers, these controllers are not suitable for curved applications. The pivot points of the ice-tong pattern controller, which are necessary for its operation, cannot be aligned properly if an arc is present in profile of the slot diffuser. Additionally, an ice-tong pattern controller cannot be rotated to accommodate a curved diffuser profile because the curvature of the ice-tong pattern controller cannot maintain alignment within the diffuser frame. Ice-tong pattern controllers can be adjusted to alter the direction and velocity of air flow, but such adjustments require the manual placement and use of extra positioning parts to selectively “hang” the ice-tong pattern controller elements in a desired manner. The installation of these extra positioning parts increases the necessary cost, materials, and assembly time. This is particularly problematic when adjustability is not a requirement for the application.
Other conventional air pattern controllers used in conjunction with slot diffusers include blade-style pattern controllers. Blade pattern controllers are fixedly mounted to a slot diffuser side wall at a mounting end, and direct air around a working end and out of the corresponding air slot in a fixed direction. These pattern controllers are typically L-shaped extrusions, with a short arm connected at a vertex to a long arm. The short arm extends from the mounting end, and is permanently fixed to the side wall, typically by spot welding, such that the long arm extends substantially perpendicularly into the air slot space to direct the flow of air as it exits the slot diffuser. L-shaped blade pattern controllers can be modified for use in conjunction with a curved slot diffuser. This curvature, however, often results in erratic throw patterns.
Though blade pattern controllers generally allow for easy installation with few necessary parts in fixed applications, use of a blade pattern controller in a curved application as described above requires laborious, time-consuming, and skilled constructing, notching, positioning, and mounting. Further, the L-shaped blade pattern controller profiles tend to twist when manufactured, and when installed in curved slot diffusers because the neutral axis does not lie in a plane perpendicular to the direction of curvature. Thus, constructing a slot diffuser with an L-shaped blade pattern controller requires a fourth surface to counteract twisting, which must be tuned manually with high precision.
Testing has shown that L-shaped blade pattern controllers do not perform well when compared with conventional air pattern controllers, including the ice-tong pattern controller. L-shaped blade pattern controllers used in conjunction with slot diffusers typically suffer from high noise output and an unacceptable pressure drop when air is directed over the knife or square working edge. Often, a complete loss of pattern control results. Further, the gap between the room-side of the pattern controller and the frame flange also contributes to the pressure drop because a Coand{hacek over (a)} effect is not generated until the fluid stream leaves the diffuser.
Conventional air pattern controllers, thus, are not ideally suited for use in slot diffusers with curves or other shapes. Air pattern controllers that are capable of being used in curved or shaped slot diffusers typically suffer from poor performance, and must be significantly modified such that the construction, shape, and/or mounting of each air pattern controller is unique to the specific application. What is needed is an air pattern controller that can easily be mounted in a desirable position within a linear, curved, angled, or shaped slot diffuser. Further, a single air pattern controller design is needed for universal use in all available slot diffuser shapes without modification of the controller. Still further, an air pattern controller is needed that can be mounted within a slot diffuser using a small amount of time and parts. It is to these needs and others that the present invention is directed.
A universal air pattern controller in accordance with an embodiment of the present invention comprises at least one elongate, tubular element mounted within a slot diffuser frame. The substantially smooth and curved surface of the universal air pattern controller provides superior performance when compared with conventional air pattern controllers, especially when used in curved or uniquely-shaped slot diffusers. The tubular profile of the universal air pattern controller allows for quick and easy mounting within a slot diffuser of any shape without further modification.
In an exemplary embodiment, the universal air pattern controller is used in conjunction with a two-slot air diffuser. The slot diffuser comprises two side frames mounted on opposing sides of a center frame. A linear bar, H-bar, or other conventional spacer joins the side frames and the center frame, and provides structural support to the slot diffuser. The side frames each have a flange extending from a bottom edge of the side frame toward the center frame. The center frame likewise has two flanges extending from its bottom edge toward each corresponding opposing side frame. The side and center frames can be slidably mounted at their top edges to the H-bar on a track having an upper and lower lip, or can be fixedly mounted with screws, bolts, welding, or the like, or can be snapped into place into a reciprocally mating profile.
In one embodiment, a tubular universal air pattern controller is mounted in each of two air slots and abuts both the side frame flange and the lower lip of the side frame track such that both universal air pattern controllers are mounted distal to the center frame. Alternatively, the universal air pattern controllers can be mounted such that each abuts the center frame flange and the lower lip of the center frame track. In this embodiment, both universal air pattern controllers are mounted proximal to the center frame. Also alternatively, any combination of these positions can be employed to achieve flow patterns in opposite directions from selected air slots.
Once positioned, the universal air pattern controllers can be held into place with one or more spring clips. In one embodiment, the spring clips can have a profile adapted at a first end to mate with the lower lip of a side frame track or center frame track, and at a second end to abut and firmly hold the universal air pattern controller into place. The spring clips of this exemplary embodiment are removably attached, and can be applied at regular or desired intervals in order to secure the universal air pattern controller within the slot diffuser. In other embodiments, the spring clip is fixedly attached.
The universal air pattern controller of the present invention mounted within a slot diffuser induces a maximized Coand{hacek over (a)} effect when the curved surface of the tubular universal air pattern controller is applied into an air stream. This is because the working surface of the of the universal air pattern controller transitions seamlessly, or at least provides a substantially smooth or curved transition, into the interior frame surface. Thus, the Coand{hacek over (a)} effect is created at a point before the fluid leaves the slot diffuser, which causes the air to flow in a tight path across the ceiling of an occupied space.
The universal air pattern controllers can be mounted in a fixed position against the side frames and side frame flanges or the center frame and the center frame flanges of the diffuser with conventional mechanical fasteners to hold them in position. The universal air pattern controllers can be mounted in both curved and straight slot diffusers with one or more spring clips without the requirement of additional mounting parts. In an alternative embodiment, the universal air pattern controllers can be applied in pattern-adjustable slot diffusers by implementing only pattern controller translation because the universal air pattern controller itself is not required to rotate, even as it translates along a curved path.
Although the universal air pattern controller is not strictly required to be unitarily tubular or perfectly circular in accordance with the present invention, this embodiment of the universal air pattern controller is preferred. The universal air pattern controller can easily be manufactured using a 3-point roll former or similar equipment without significant deformation or twisting because of the orientation of the neutral axis the even surface relative to the roll-former.
These features, and other features and advantages of the present invention will become more apparent to those of ordinary skill in the relevant art when the following detailed description of the preferred embodiments is read in conjunction with the appended drawings in which like reference numerals represent like components throughout the several views.
a is a front elevation view of two universal air pattern controllers positioned in a linear dual slot diffuser with an end cap removed, showing a distal positioning of the universal air pattern controllers and a horizontal direction of airflow.
b is a bottom perspective view of a curved dual slot diffuser showing a distal positioning of the universal air pattern controllers.
Illustrative embodiments of a universal air pattern controller 15 for controlling the flow of air from a slot diffuser 10 into an occupied space in accordance with the present invention are shown in
The side frames 20 each have a single narrow longitudinal flange 30 formed as an integral extrusion and extending inwardly toward the air slot 45 at a bottom edge. In one embodiment, side frames 20 further comprise a track 40 having an upper lip 40a at a top edge and a lower lip 40b between the top edge and the flange 30, which define a recessed area 41. The track 40 faces inwardly toward the air slot 45, and can be formed integrally with the side frame 20 extrusion, or can be mechanically attached thereto.
The center frame 25 is an intermediate wall within the diffuser having a “T-shaped” cross-section, and forms a means for dividing the space between the opposing side frames 20 and a support for the structure. The center frame 25 comprises two narrow longitudinal flanges 30 formed as an integral extrusion, each extending in opposite directions toward a flange 30 of a corresponding side frame 20. Both flanges 30 of the center frame 25 join together to form a continuous surface and create the “T-shape” of the extrusion. The flanges 30 are intended to be mounted in overlapping fashion with adjacent ceiling tiles (not shown) in the ceiling of the occupied space in which the slot diffuser is to be mounted. The center frame 25 also optionally comprises two tracks 40, each having an upper lip 40a at a top edge and a lower lip 40b between the top edge and the flanges 30 of the center frame 25, which define recessed areas 43. Each track 40 faces a side frame 20, and can be formed integrally with the center frame 25 extrusion, or can be mechanically attached thereto.
The center frame 25 can be mounted to each side frame 20 via a spacer, for example, a dual-sided horizontal H-bar 35. In this embodiment, the H-bar 35 has portions on each side capable of mating with a track 40 on either or both of a side frame 20 or a center frame 25 such that the H-bar 35 is adapted to slidably connect to the side frames 20 and the center frame 25. The center frame 25 is attached to a side frame 20 by slidably mounting the correspondingly-shaped portion on the side of the H-bar 35 into a recessed area 47 (
In other embodiments, as seen in
The universal air pattern controller 15 in accordance with an embodiment of the present invention comprises one or more elongate, tubular elements 15 mounted within each air slot 45 of the slot diffuser 10. The universal air pattern controller 15 abuts both the flange 30 and the lower lip 40b of the track 40 of the side frame 20. Preferably, the universal air pattern controller 15 is a single, unitary and enclosed tube with a circular cross section extending substantially the length of the slot diffuser 10. In dual-slot applications, two universal air pattern controllers 15 are mounted distal to the center frame 25. Alternatively, the pair of universal air pattern controllers 15 can be mounted such that each abuts one of the flanges 30 of the center frame 25 and one of the lower lips 40b of the track 40 of the center frame 25. In this alternative embodiment, both universal air pattern controllers 15 are mounted adjacent to the center frame 25. Also alternatively, any combination of mounting positions can be employed to achieve the desired air flow into the occupied space. In single-slot applications, at least one universal air pattern controller 15 is mounted on either side frame 20 between its corresponding flange 30 and lower lip 40b in a first position 50a (shown in
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Traditionally, slot diffusers incorporating complex shapes or special materials required complete re-engineering of the component parts in order to provide an acceptable level of air pattern control. The universal air pattern controllers 15 and 115 in accordance with the present invention have a single design for straight, curved, and shaped slot diffusers 10 and 110, that is easy to manufacture and install and provides superior air pattern control to linear, concave or convex curved, circular, ovular, triangular, and hexagonal applications, for example, without the need to re-engineer and fabricate the working components within the slot diffusers 10 and 110.
Preferably, the side frames 20 and the center frame 25 of the slot diffuser 10 used in conjunction with the universal air pattern controller 15 are of a solid extruded aluminum construction. Alternatively, the side frames 20 and the center frame 25 can be constructed of specialized materials for architectural or functional purposes, like stainless steel, brass, bronze, or other materials that would traditionally limit conventional fabrication of the slot diffusers 10 and make the mounting of the universal air pattern controller 15 particularly difficult.
The universal air pattern controller 15 is preferably constructed of extruded aluminum. Although building codes and other regulations may restrict the materials that can be used, in certain application, in application where codes and regulations do not so limit the materials to be used, the universal air pattern controller 15 can be constructed from any durable material capable of being bent or shaped to correspond to the contours of the slot diffuser 10. Alternatively, the universal air pattern controller 15 can be constructed from a flexible material such as rubber, plastic, thermoplastic, polypropylene, polyurethane, polyethylene, polyvinyl chloride and the like. The universal air pattern controller 15 can also be constructed of corrugated metal or plastic, braided wire, interlocking metal, multiple flexible layers of material, or incorporate fibrous reinforcement like braided nylon. The universal pattern controller 15 and can be extruded, injection molded, or formed from other methods known in the art, and can be shaped during fabrication, or at any time prior to installation.
Because the curved, aerodynamic surface of the universal air pattern controller 15 of the slot diffuser 10 induces a maximized Coand{hacek over (a)} effect at a point just before the fluid leaves the slot diffuser 10, it is capable of creating tight, ceiling-hugging horizontal air patterns as well as vertical air patterns. Also advantageously, the universal air pattern controller 15 can easily be manufactured and shaped using standard equipment like a 3-point roll former without significant deformation or twisting. Though a circular cross section is preferred, the universal air pattern controller 15 can have a cross section that is oval, ovoid, or other substantially rounded shapes. The surface of the universal air pattern controller 15 is preferably smooth, but can alternatively incorporate textures that do not substantially interfere with the air flow across the surface. Finally, the universal air pattern controller 15 need not be completely enclosed to form a true tube, but rather, must be at least substantially enclosed such that the working surface of the universal air pattern controller 15 is continuous.
While this invention has been described with reference to preferred embodiments thereof, it is to be understood that variations and modifications can be affected within the spirit and scope of the invention as described herein and as described in the appended claims.
