Patent Description:
Suspension grids that hold up acoustic ceiling tiles, lighting fixtures, or other tiles or panels are effective for constructing an attractive and convenient ceiling. The suspension grid allows the builder to provide a clean and uninterrupted boundary to the space below the ceiling while hiding infrastructure such as structural members, heating, ventilation and air conditioning (HVAC) components, wiring, and plumbing in a plenum space above the ceiling. Further, suspension ceilings provide the benefit of being modular. If works needs to be done above the ceiling, a small portion can be temporarily removed to provide access above the ceiling. Likewise, if any portion of the ceiling is damaged, that portion can be replaced without deconstructing the entire ceiling.

When the plenum space is used to house HVAC components above the suspension ceiling, the HVAC components need fluid access to the underlying living or working space. In conventional systems, vents or diffusers are provided in the ceiling that provide air to or receive air from the underlying space. In some cases, these vents or diffusers replace an entire acoustic ceiling tile in the ceiling system. But such a large vent is considered unattractive and not cohesive with the rest of the ceiling.

Alternative solutions use more subtle diffusers that do not cover the space of an entire ceiling tile. However, these diffusers still provide an inconsistency in the visual of the ceiling. Moreover, installing such diffusers can be complicated. Often the ceiling grid is customized in certain areas to accommodate the diffuser, which may require cutting the ceiling grid beams, cutting the ceiling tiles, or both. Relevant prior art is disclosed in <CIT> and <CIT>.

The present inventors have recognized that a system providing ventilation without interrupting the pattern or visual of the ceiling and that is uncomplicated to install would be attractive to builders and designers.

In one example, the present disclosure provides a vented support beam for a suspension ceiling comprising:.

In one aspect, the disclosure provides a suspension ceiling ventilation system comprising:.

In another example, the disclosure provides a method of constructing a suspension ceiling ventilation system, the method comprising:.

Additional aspects of the disclosure will be evident from the disclosure herein.

The accompanying drawings are included to provide a further understanding of the methods and devices of the disclosure, and are incorporated in and constitute a part of this specification. The drawings are not necessarily to scale, and sizes of various elements may be distorted for clarity. The drawings illustrate one or more embodiment(s) of the disclosure, and together with the description serve to explain the principles and operation of the disclosure.

As described above, the present inventors have noted that conventional ventilation systems interrupt the pattern and visual of the ceiling surface. The present inventors have developed a suspension ceiling support beam and ventilation system that avoids the need to interrupt the ceiling surface and avoids the need for complicated installation methods.

Accordingly, one aspect of the disclosure is a vented support beam for a suspension ceiling including an elongate body extending in a longitudinal direction, the body including a vertical web and opposing first and second flanges protruding laterally from the vertical web. The vented support beam also including a vent formed through the first flange. Such a vented support beam is shown in perspective view in <FIG>. Vented support beam <NUM> includes a vertical web <NUM> and two flanges <NUM>, <NUM> protruding laterally from the web <NUM>. First flange <NUM> is disposed on one side of web <NUM> and second flange <NUM> is disposed on the other. A first vent <NUM> extends through the first flange <NUM> providing fluid communication between a space above first flange <NUM> and a space below the flange.

In certain embodiments as otherwise described herein, the vented support beam further comprises another vent formed through the second flange. For example, vented support beam <NUM> includes a second vent <NUM> formed through second flange <NUM>, like first vent <NUM>, second vent <NUM> provides fluid communication between a space above and a space below second flange <NUM>.

In certain embodiments as otherwise described herein, a width of the beam is in a range from ¼ inch (<NUM>,<NUM>) to <NUM> inches (<NUM>,<NUM>), e.g., from <NUM>/<NUM> to 1½ inches(<NUM>,<NUM>-<NUM>,<NUM>), e.g., from ½ inch to <NUM> inch (<NUM>,<NUM>-<NUM>,<NUM>). Further, in certain embodiments as otherwise described herein, a height of the beam is in a range from <NUM> inch to <NUM> inches (<NUM>,<NUM>-<NUM>,<NUM>), e.g., from 1½ inches to <NUM> inches (<NUM>,<NUM>-<NUM>,<NUM>). Vented support beam <NUM> has a width of <NUM>/<NUM> of an inch (<NUM>,<NUM>) and a height of <NUM>% inches (<NUM>,<NUM>). The width of vented support beam <NUM> is governed by the lateral extent of the first and second flanges <NUM>, <NUM>, which form the widest part of vented support beam <NUM>. In other embodiments, other components of the vented support beam may form the widest part of the support beam. The height of vented support beam <NUM> extends from a bulb <NUM> disposed at the upper end of the beam and a box profile <NUM> disposed at the lower end of the vented support beam <NUM>, both of which are described in more detail below.

In certain embodiments as otherwise described herein, the vent extends at least <NUM> inches (<NUM>,<NUM>) in the longitudinal direction, e.g., at least <NUM> inches, (<NUM>,<NUM>) e.g., at least <NUM> inches (<NUM>,<NUM>). For example, in vented support beam <NUM>, vent <NUM> in first flange <NUM> extends from a first end <NUM> of the vented support beam to a second end <NUM>. In other embodiments, the vent spans a smaller portion of the length of the vented support beam. Still in other embodiments, several vents are provided in a series along the length of the first flange.

In certain embodiments as otherwise described herein, the vent includes a plurality of holes disposed in a line along the longitudinal direction. For example, vent <NUM> includes a plurality of circular holes <NUM> disposed in a line that runs along a side of support web <NUM>. In other embodiments, the holes may have various other shapes, as will be appreciated by the person of ordinary skill in the art.

The term vent, as used herein, refers to a single aperture or several apertures that are in close proximity to one another. For example, a vent may be formed along the longitudinal direction by several holes where the distance between two of the holes is no more than twice the length of the opening in the longitudinal direction. As the term vent is used herein, holes separated by more than this distance along the longitudinal direction constitute separate vents.

In certain embodiments as otherwise described herein, the vent includes a slot extending along the longitudinal direction. A vented support beam including such a vent is shown in <FIG>. Similar to vented support beam <NUM>, vented support beam <NUM> includes a support web <NUM> and first and second flanges <NUM>, <NUM> protruding laterally therefrom. Further, two vents <NUM> are provided in first flange <NUM>. One vent <NUM> is disposed at one end of vented support beam <NUM> and another vent <NUM> is disposed at the other end. In some embodiments, additional vents are provided along the length of the vented support beam. Vent <NUM> is formed as a slot that extends in the longitudinal direction. While vents <NUM> have rounded ends, in other embodiments, the openings forming the vents may have other shapes.

In certain embodiments as otherwise described herein, the vented support beam further comprises a channel disposed adjacent to the first and second flanges, where the channel is in fluid communication with the vent. In certain embodiments as otherwise described herein, the channel is formed by a first side wall projecting down from an outer edge of the first flange and a second side wall projecting down from an outer edge of the second flange. For example, vented support beam <NUM> includes a channel <NUM> that is adjacent to and in fluid communication with vent <NUM>. Accordingly, vent <NUM> provides fluid access between channel <NUM> and the space above first flange <NUM>. Channel <NUM> is formed by the first and second flanges <NUM>, <NUM> in combination with first side wall <NUM> and second side wall <NUM>. First sidewall <NUM> projects down from an outer edge <NUM> of first flange <NUM> and second sidewall <NUM> similarly projects down from an outer edge <NUM> of second flange <NUM>. As a result, the sidewalls <NUM>, <NUM> and flanges <NUM>, <NUM> provide an enclosed space that forms channel <NUM>.

In certain embodiments as otherwise described herein, the channel is enclosed in a box profile disposed below the first and second flanges. In certain embodiments as otherwise described herein, the box profile includes a slot opposite the first and second flanges, where the slot extends in the longitudinal direction. For example, in vented support beam <NUM>, channel <NUM> is provided in a box profile <NUM> taking the form of an architectural feature of a bolt slot ceiling grid beam. In particular, box profile <NUM> includes a slot <NUM> positioned at the lower end thereof opposite the first and second flanges <NUM>, <NUM>. The combination of vent <NUM> through first flange <NUM> at the top of box profile <NUM> and the slot <NUM> at the bottom of box profile <NUM> allows air to pass through the channel <NUM> from above the vented support beam <NUM> to below the beam or vice versa. The inclusion of this fluid path through the box profile <NUM> of vented support beam <NUM> allows the ventilation system to utilize a fluid path in a concealed location, as explained in more detail below.

While box profile <NUM> of vented support beam <NUM> takes the form of an architectural feature of a bolt slot beam, in other embodiments, the box profile has a different shape. For example, vented support beam <NUM>, shown in <FIG>, includes a channel <NUM> that is disposed within box profile <NUM>. The box profile <NUM> is in the form of a narrow bulb disposed beneath first and second flanges <NUM> and <NUM>. Similar to the channel of vented support beam <NUM>, channel <NUM> is in fluid communication with vent <NUM> passing through first flange <NUM>. However, fluid access out of box profile <NUM> is provided by openings <NUM>, <NUM> in the sidewalls <NUM>, <NUM> of the box profile <NUM>, rather than a slot at the bottom of the box profile.

In certain embodiments as otherwise described herein, the vented support beam is in the form of a T-beam. For example, vented support beam <NUM>, shown in <FIG>, includes first and second flanges <NUM>, <NUM> that protrude laterally from a web <NUM>. Each of the first and second flanges <NUM>, <NUM> includes a respective vent <NUM>, <NUM> in the form of several rows of holes extending through the flanges.

In certain embodiments as otherwise described herein, the beam has a box profile that includes a first sidewall, a second sidewall, a first lip connected to the first sidewall that borders the slot, and a second lip connected to the second sidewall that borders the slot. For example, the box profile <NUM> of vented support beam <NUM> includes a includes a first lip <NUM> extending inward from first sidewall <NUM> and a second lip <NUM> extending inward from second sidewall <NUM> toward first lip <NUM>. Slot <NUM> is formed between the inner ends of first lip <NUM> and second lip <NUM>.

In certain embodiments as otherwise described herein, the vented support beam is formed of of a cut and shaped metal sheet. In some embodiments, the vented support beam is formed from a single metal sheet that is bent and cut into the shape of the beam. The term metal sheet, as used herein, is not limited to any particular thickness and may include materials conventionally referred to as metal foil, sheet metal, metal plate or metal strips. In certain embodiments, the vented support beam is formed of steel or aluminum. In other embodiments, the vented support beam is a polymer beam. In some embodiments the polymer beam is extruded, molded, or a combination thereof.

In certain embodiments as otherwise described therein, the web includes adjacent first and second support walls, and wherein the vent is disposed laterally outside of the first and second support walls. For example, vented support beam <NUM> includes a double-walled web <NUM> including a first support wall <NUM> and a second support wall <NUM>. The two support walls <NUM>, <NUM> are formed from a single metal sheet that is folded back on itself to form the double-walled web.

In certain embodiments as otherwise described herein, an inner surface of the first support wall abuts an inner surface of the second support wall. For example, first and second support walls <NUM>, <NUM> are immediately adjacent such that the neighboring surfaces of the support walls abut one another. In some embodiments, the support walls are stitched to one another. For example, along the length of web <NUM> indentations <NUM> are made that deform both support walls <NUM>, <NUM> forming a connection between the walls and strengthening the web <NUM>.

In certain embodiments as otherwise described herein, the vented support beam further includes a bulb attached to an upper end of the web, and the first and second flanges are disposed at a lower end of the web. For example, the metal sheet that forms the two support walls <NUM>, <NUM> is looped at the top of vented support beam <NUM> in the form of a bulb <NUM>. The widened bulb strengthens the beam and improves bending resistance. At the lower end of web <NUM>, the metal sheet is bent outward to form the opposing webs <NUM>, <NUM>. The metal sheet continues around the box profile <NUM> and ends with respective hems at the inner ends of lips <NUM>, <NUM>.

In some embodiments, the vented support beam includes a clip for attaching the beam to neighboring components of a ceiling grid. For example, each of the first and second ends <NUM>, <NUM> of vented support beam <NUM> includes a clip <NUM> configured to attach vented support beam <NUM> to a receiving space in the center of another beam or to the end of another beam. In particular, clip <NUM> can be attached to a similar clip extending in the same direction as vented support beam <NUM>, both of which are held in a receiving space in the middle of a third beam.

In another aspect, the disclosure provides a suspension ceiling ventilation system including a plurality of support beams arranged in a ceiling grid so as to form a plurality of grid openings in the ceiling grid. Each of the support beams includes a vertical web and opposing flanges protruding laterally from the vertical web. At least a portion of the plurality of support beams are vented support beams according to any of the embodiments set forth above. The system further comprises a plurality of ceiling tiles, where each of the ceiling tiles is disposed in a respective grid opening of the ceiling grid so as to form a suspension ceiling. The suspension ceiling provides a plenum space above the ceiling and an underlying space below the ceiling. A portion of such a suspension ceiling ventilation system is schematically depicted in <FIG>. System <NUM> includes a plurality of support beams <NUM> that are arranged in a ceiling grid <NUM> in a manner that forms a plurality of openings <NUM>. <FIG> is a cross section where only three of the support beams <NUM> are visible. However, ceiling grid <NUM> includes further support beams that run perpendicular to support beams <NUM>.

Each of the support beams <NUM> in ceiling grid <NUM> has a similar configuration to that of vented support beam <NUM> and includes a double-walled vertical web, opposing flanges that protrude laterally from the web and establish a box profile at the lower end of the web, and a bulb at the upper end of the web. Indeed, a portion of the support beams <NUM> in ceiling grid <NUM> are vented support beams <NUM> that are identical to vented support beam <NUM>. The remaining support beams <NUM> are similar to the vented support beam <NUM>, differing only in that they do not include a vent. <FIG> shows two vented support beams <NUM> and one non-vented support beam <NUM>.

System <NUM> further includes a plurality of ceiling tiles <NUM> disposed in the grid openings <NUM> formed in ceiling grid <NUM>. The combination of the ceiling tiles <NUM> and ceiling grid <NUM> forms a suspension ceiling <NUM> that provides a plenum space <NUM> above the suspension ceiling and an underlying space <NUM> below the ceiling.

Each of the grid openings has a width and a breadth for holding a respective ceiling tile. As used herein, the term grid opening refers to the standardized openings in the middle of the grid, and not to the openings at the perimeter of the grid, which may be sized differently, and are described further below. In certain embodiments as otherwise described herein, each of the grid openings has a width is in a range of <NUM> to <NUM> inches (<NUM>-<NUM>), e.g., <NUM> to <NUM> inches (<NUM>,<NUM>-<NUM>). In certain embodiments, each grid opening has a breadth in a range of <NUM> to <NUM> inches (<NUM>-<NUM>), e.g., a breadth in a range of <NUM> to <NUM> inches (<NUM>-<NUM>), e.g., <NUM> to <NUM> inches (<NUM>,<NUM>-<NUM>).

In certain embodiments as otherwise described herein, each of the flanges of the support beams includes a contact area, and the ceiling tiles are supported by the respective contact areas of the support beams. For example, as shown in the detailed view of <FIG>, at least a portion of the flanges of support beams <NUM> provide a contact area disposed on a surface on an upper side of the flange for contacting a ceiling tile <NUM> that is placed in the neighboring grid opening <NUM>. Accordingly the ceiling grid <NUM> provides support for ceiling tiles <NUM> that are placed in grid openings <NUM>.

In certain embodiments as otherwise described herein, the contact area of the first flange of the vented support beam includes an outside portion of the first flange, and the vent through the first flange extends through an inside portion of the first flange. For example, vented support beam <NUM>, as shown in the detailed view of <FIG>, includes contact area <NUM> on an outside portion of first flange <NUM>, while vent <NUM> is formed through the inside portion of first flange <NUM>. Accordingly, when ceiling tile <NUM> is placed on contact area <NUM>, vent <NUM> is unobstructed and air can flow therethrough.

The term outside portion, as used herein, refers to a portion that is at the lateral outer side of the support beam, i.e., a portion that is away from the horizontal center of the support beam. Likewise, means the inside portion is a portion that is nearer the horizontal center of the support beam.

In certain embodiments as otherwise described herein, each of the ceiling tiles includes a central body and a projection extending from an edge of the central body. Each of the projections is supported by a respective flange of an adjacent support beam. For example, as shown in the detailed view in <FIG>, ceiling tile <NUM> includes a central body <NUM> and a projection <NUM> extending outward from an outer edge of the central body. The projection <NUM> allows ceiling tile <NUM> to be supported on first flange <NUM> while the lower end of vented support beam <NUM> and the lower surface of ceiling tile <NUM> are flush. The flush positioning of the support beam <NUM> and ceiling tile <NUM> provides an attractive continuous lower surface of the suspension ceiling <NUM>. In other embodiments, the lower surface of the ceiling tile is flat, and the body of the ceiling tile is supported directly by the flange.

In certain embodiments as otherwise described herein, each of at least a portion of the ceiling tiles includes a notch that forms an opening in the respective ceiling tile to provide fluid access to the vent of a respective vented support beam. For example, in the detailed view of suspension ceiling ventilation system <NUM>, shown in <FIG>, portions of the projection <NUM> of ceiling tile <NUM> extend over the entire width of flange <NUM>. However, to provide fluid access to vent <NUM>, the ceiling tile, particularly the projection of the ceiling tile includes a notch <NUM> positioned over the hole forming vent <NUM>. Accordingly, air can flow through notch <NUM> to reach vent <NUM>.

In certain embodiments as otherwise described herein, at least a portion of the ceiling tiles include a gasket disposed at an outer edge thereof, wherein the gasket contacts a respective flange of at least one of the support beams. For example, in suspension ceiling ventilation system <NUM>, shown in <FIG>, the ceiling tiles <NUM> each include a gasket <NUM> disposed between the projection <NUM> of ceiling tile <NUM> and the flange <NUM> of the vented support beam <NUM>. In some embodiments, the gasket forms a seal between the ceiling tile and the support beam, which forces air through the vent instead of through any gap between the ceiling tile and the adjacent flange. Moreover, the use of the gasket allows the ceiling tile to be set back from the vent, which can improve air flow through the vent.

In certain embodiments as otherwise described herein, the plenum space has a first pressure and the underlying space has a second pressure that is different from the first pressure so as to force air through the respective vents of the vented support beams. In certain embodiments as otherwise described herein, the suspension ceiling ventilation system further includes a duct providing fluid communication between the plenum space and a compressor. For example, ventilation system <NUM> includes a duct <NUM> that extends into plenum space <NUM>. Duct <NUM> is downstream of a compressor that forces air into plenum space <NUM> creating an elevated pressure therein. The elevated pressure in plenum space <NUM> forces air through the vented support beams <NUM> and into underlying space <NUM>. In other embodiments, the duct is upstream of the compressor, which drives air out of the plenum space. For example, in ventilation system <NUM>, shown in <FIG>, duct <NUM> is connected to plenum space <NUM> and is located upstream of a compressor that removes air from plenum space <NUM>. The compressor therefore creates a pressure drop in plenum space <NUM> so that air flows from the underlying space <NUM> through the vented support beams <NUM> of suspension ceiling <NUM> and into the plenum space <NUM>.

In certain embodiments as otherwise described herein, the suspension ceiling ventilation system includes a divider that separates a first section of the plenum space from a second section of the plenum space. Further, the first section of the plenum space has a first pressure, the second section of the plenum space has a second pressure and the underlying space has a third pressure that is between the first and second pressures so as to force air from the first section of the plenum space to the underlying space through respective vents of a first group of the vented support beams and to force air from the underlying space to the second section of the plenum space through respective vents of a second group of the vented support beams. For example, ventilation system <NUM>, shown in <FIG>, includes a divider <NUM> within the plenum space <NUM> that divides the plenum space into a first section <NUM> and a second section <NUM>. Likewise, a first duct <NUM> extends into the first section <NUM> of the plenum space <NUM>, and a second duct <NUM> extends into the second section <NUM> of the plenum space <NUM>. One or more compressors in fluid communication with the air ducts <NUM>, <NUM> causes a pressure differential between the first section <NUM> and second section <NUM>. The pressure differential between the two sections <NUM>, <NUM> of the plenum space causes air to flow into the underlying space <NUM> through the vented support beams <NUM> that are adjacent to the first section of the plenum space. Likewise, the pressure differential further causes the air to flow from the underlying space <NUM> into the second section <NUM> of the plenum space through the associated vented support beams. Thus, the vented support beams <NUM> of the suspension ceiling <NUM> provide both the air supply and return for the underlying space <NUM>. The divider <NUM> in ventilation system <NUM> is attached to a support beam of the suspension ceiling. In other embodiments, the divider may be integrally formed with one of the support beams. Alternatively, the divider may divide the plenum space in other ways as will be appreciated by those of ordinary skill in the art.

In certain embodiments as otherwise described herein, a first portion of the support beams extend in a first direction and a second portion of the support beams extend in a second direction, where the first direction is at an angle to the second direction. For example, ceiling <NUM>, shown in <FIG> includes a ceiling grid <NUM> with a plurality of support beams running perpendicular to one another. A first portion of the support beams run along the length of the ceiling <NUM> and a second portion run across the width of the ceiling.

In certain embodiments as otherwise described herein, the first portion of support beams includes main runners that span a plurality of the grid openings of the ceiling grid, and the second portion of support beams includes cross beams that extend from a respective one of the main runners to a neighboring main runner. For example, ceiling grid <NUM> includes main runners <NUM> that run along the entire length of ceiling <NUM> and span six grid openings <NUM> and the corresponding ceiling tiles <NUM>. While the main runners in ceiling <NUM> span the entire length of the ceiling, in other embodiments, the main runners extend across multiple openings but span only a fraction of the ceiling. Cross beams <NUM> extend between neighboring pairs of main runners <NUM>. Together, a group of cross beams <NUM> spans the width of ceiling <NUM>. In other embodiments, the main runners extend across the width of the ceiling while the cross beams extend across the length.

In certain embodiments as otherwise described herein, a first portion of the cross beams are vented support beams and a second portion of the cross beams are unvented support beams. For example, in ceiling <NUM>, there are four rows of cross beams <NUM>. Two of the rows are entirely formed with cross beams <NUM> taking the form of vented support beams <NUM>. The other two rows include both cross beams <NUM> in the form of vented support beams <NUM> and unvented support beams <NUM>. In certain embodiments, the fraction of the ceiling grid that is formed by vented support beams impacts the flow of air between the plenum space and the underlying space. Because of the large number of cross beams <NUM>, the using cross beams that are both vented and unvented allows a builder to select a precise percentage of the grid that is formed with vented support beams, which allows fine tuning of the flow rate between the plenum space and underlying space. While the main runners <NUM> in ceiling <NUM> are unvented, in other embodiments, the main runners are vented. Still in other embodiments a portion of the main runners are vented and a portion are unvented.

In certain embodiments as otherwise described herein, the grid forms edge openings along at least one perimeter edge of the suspension ceiling, and the suspension ceiling ventilation system further comprises ceiling tile sections disposed in the edge openings. For example, the openings <NUM> around the perimeter of ceiling <NUM> are smaller than the grid openings <NUM> in the center of the ceiling. To form a continuous surface across the ceiling, a section of ceiling tile <NUM> is positioned in each of the edge openings <NUM>.

While the vented ceiling grid allows for fewer interruptions in the ceiling surface, in some embodiments the ceiling includes features that interrupt the ceiling tiles of the suspension ceiling. For example, in some embodiments the ceiling includes lighting fixtures and emergency components, such as sprinklers. In some embodiments, the ceiling includes one or more diffusers that cooperate with the vented ceiling grid.

In another aspect, the disclosure provides a method of constructing a suspension ceiling ventilation system according to any of the embodiments described above. The method includes arranging a plurality of support beams in a ceiling grid that is coupled to a support structure, where the ceiling grid includes a plurality of grid openings between the support beams. Each of the support beams includes a vertical web and opposing flanges protruding laterally from the vertical web, wherein at least a portion of the plurality of support beams are vented support beams. The method further includes positioning each of a plurality of ceiling tiles in a respective grid opening of the ceiling grid so as to form a suspension ceiling, where the suspension ceiling provides a plenum space above the ceiling and an underlying space below the ceiling.

For example, ceiling <NUM> of <FIG> includes a ceiling grid <NUM> that is coupled by brackets <NUM> to a wall <NUM> disposed around the perimeter of ceiling <NUM>. For example, in some embodiments each of the beams at the outer perimeter of ceiling grid <NUM> is attached to a respective bracket <NUM> using mechanical fasteners which are, in turn, attached to the wall <NUM>. The ceiling grid <NUM>, once assembled, forms a plurality of grid openings <NUM> and edge openings <NUM>. To complete the ceiling <NUM>, ceiling tiles <NUM> are inserted into the grid openings <NUM> and ceiling tile sections are inserted into the edge openings <NUM>. At least a portion of the support beams take the form of vented support beams <NUM>.

In certain embodiments as otherwise described herein, the method further includes providing a notch at an outer edge of at least one of the plurality of ceiling tiles so as to form an opening in the respective ceiling tile to provide fluid access to the vent of a respective vented support beam. For example, in some embodiments, a notch, such as notch <NUM> shown in suspension ceiling ventilation system <NUM>, is added to the ceiling tile at installation. For example, in some embodiments, the builder removes the notch before placing the ceiling tile on the flange of a respective beam. In some embodiments an area corresponding to the notch is perforated to allow for easy removal of the notch during installation. In other embodiments, the notch is formed at the manufacturing cite.

In certain embodiments as otherwise described herein, the method further includes coupling a duct to the plenum space, where the duct is in fluid communication with a compressor, and operating the compressor so as to provide a pressure differential between the plenum space and the underlying space so as to force air through the respective vents of the vented support beams. For example, as explained above, in system <NUM> a compressor is in fluid communication with duct <NUM> and is operated to force air into plenum space <NUM>. This forced air then creates an increase in pressure, which forces air through the vented support beams <NUM> into underlying space <NUM>.

In certain embodiments as otherwise described herein, a first portion of the support beams extend in a first direction and a second portion of the support beams extend in a second direction, and wherein the first direction is at an angle to the second direction. For example, in the installation of ceiling <NUM>, the main runners <NUM> of the ceiling grid <NUM> are arranged to extend in the length direction. In contrast, the cross beams <NUM> are arranged to extend in the width direction, at <NUM> degrees from the main runners <NUM>.

In certain embodiments as otherwise described herein, the method further includes selecting the number of vented support beams in the ceiling grid based on a desired air flow rate between the plenum space and the underlying space. For example, as explained above, in certain embodiments, a portion of the ceiling grid is formed by vented support beams and a portion is formed by unvented support beams. Due to the extent of beams in the grid, the builder can choose the ratio of the grid that is formed by vented support beams in order to control the flow rate between the plenum space and the underlying space.

<FIG> illustrates the air flow through a vented support beam in accordance with an embodiment of the disclosure in an example ceiling construction. The example includes a room having <NUM>' (<NUM>,<NUM>) high ceilings with a ceiling area of <NUM>' x <NUM>' (<NUM>,5x4,<NUM>). The room is configured to have five air changes per hour, which corresponds to an air flow of <NUM> CFM (<NUM>,<NUM><NUM>/min). The ceiling grid is formed of <NUM> feet (<NUM>,<NUM>) of vented support beams including rows of circular holes having a diameter of <NUM>" (<NUM>,<NUM>) and spaced at <NUM>" (<NUM>,<NUM>) center-to-center, providing a total of <NUM>,<NUM> holes in the vented grid. Based on the total air flow and the number of holes, the air flow per hole was determined to be <NUM> CFM (<NUM>,<NUM>*<NUM>-<NUM> m<NUM>/min), with an average air speed of <NUM>/s.

The pressure drop between the plenum space and the underlying space that is needed to achieve the desired flow rate can be calculated based on the above figures using equations for minor head loss. Minor head loss is expressed as multiples of the velocity head, where K is the loss coefficient, and minor head loss can be used to solve for velocity as shown in equation (<NUM>).

The volumetric flow rate through an orifice is given by equation (<NUM>), where Cd, the discharge coefficient, is related to the loss coefficient as <MAT>, u is the average velocity through the orifice, and A is the cross-sectional area of the orifice. The discharge coefficient for the sharp-edged orifice can be assumed based on a handbook value of Cd = <NUM>.

Further, minor head loss is also related to pressure drop, as shown in equation (<NUM>), where ρ is density, and gc is the conversion factor for U. customary units. Combining equations (<NUM>) and (<NUM>) allows the pressure drop to be calculated based on volumetric flow rate Q, hole diameter d, and the loss coefficient Cd, as shown in equation (<NUM>). <MAT> <MAT>.

Claim 1:
A suspension ceiling ventilation system comprising:
a plurality of support beams (<NUM>) arranged in a ceiling grid (<NUM>) so as to form a plurality of grid openings in the ceiling grid (<NUM>), each of the support beams (<NUM>) including a vertical web and opposing first and second flanges (<NUM>) protruding laterally from the vertical web, wherein at least a portion of the plurality of support beams (<NUM>) are vented support beams (<NUM>), each of the vented support beams (<NUM>) including a vent (<NUM>) formed through the respective first flange (<NUM>) thereof, and a channel disposed adjacent to the first and second flanges (<NUM>) that is in fluid communication with the vent (<NUM>), wherein the channel is formed by a first side wall projecting down from an outer edge of the first flange (<NUM>) and a second side wall projection down from an outer edge of the second flange, and wherein the channel is enclosed in a box profile disposed below the first and second flanges (<NUM>) that includes a slot opposite to the first and second flanges (<NUM>);
a plurality of ceiling tiles (<NUM>), each of the ceiling tiles (<NUM>) disposed in a respective grid opening of the ceiling grid (<NUM>) so as to form a suspension ceiling (<NUM>), each of the ceiling tiles (<NUM>) including a central body (<NUM>) and a projection (<NUM>) extending from an edge of the central body, wherein each of the projections (<NUM>) is supported by a respective flange (<NUM>) of an adjacent support beam (<NUM>) such that a lower surface of the respective ceiling tile (<NUM>) is flush with a lower end of the box profile of the adjacent support beam (<NUM>),
wherein the suspension ceiling (<NUM>) provides a plenum (<NUM>) space above the ceiling and an underlying space (<NUM>) below the ceiling.