U.S. patent application number 10/384528 was filed with the patent office on 2003-12-25 for air handling system including shroud and grille, and method of use.
Invention is credited to Anderson, Dean A..
Application Number | 20030233797 10/384528 |
Document ID | / |
Family ID | 29739855 |
Filed Date | 2003-12-25 |
United States Patent
Application |
20030233797 |
Kind Code |
A1 |
Anderson, Dean A. |
December 25, 2003 |
Air handling system including shroud and grille, and method of
use
Abstract
An air handling system adapted especially for drop ceiling
gridwork employs a shroud and a grille. The grille is made of a
material meeting UL Standard 94 or 181 and rests on the drop
ceiling gridwork. The shroud is made of a material meeting at least
UL Standard 94HB, and at least its inner surface is non-reflective
to hide the shroud structure when viewed through openings in the
grille. The shroud interconnects the grille openings to an air
handling duct above the gridwork using the appropriate
fasteners.
Inventors: |
Anderson, Dean A.; (Pierson,
MI) |
Correspondence
Address: |
CLARK & BRODY
Suite 600
1750 K Street, NW
Washington
DC
20006
US
|
Family ID: |
29739855 |
Appl. No.: |
10/384528 |
Filed: |
March 11, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60391036 |
Jun 25, 2002 |
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Current U.S.
Class: |
52/218 ; 52/219;
52/220.5 |
Current CPC
Class: |
E04B 9/02 20130101; F24F
13/082 20130101 |
Class at
Publication: |
52/218 ; 52/219;
52/220.5 |
International
Class: |
E04D 013/14; E04G
015/06; E04H 012/28; E04C 002/52 |
Claims
What is claimed is:
1. In an air handling system positioned above a drop ceiling grid
system and having an air handling header, the improvement
comprising: a) a grille sized to rest on grid sections forming an
opening in the drop ceiling, the grille being made of a material
meeting UL standard 181 or at least UL standard 94HB; and b) a
shroud having a shroud body forming a first opening sized to mate
with the grille, and a second opening sized to mate with the air
handling header, the shroud body being made of a material meeting
at least UL standard 94HB and wherein an inner surface of the
shroud disposed between the first and second openings is
non-reflective.
2. The system of claim 1, wherein the shroud is made of one of a
polystyrene, a high impact polystyrene, and an ABS.
3. The system of claim 1, wherein the grille is made of glass-fiber
reinforced polypropylene.
4. The system of claim 2, wherein the grille is made of glass-fiber
reinforced polypropylene.
5. The system of claim 1, wherein the shroud and grille are
attached to each other.
6. An air handling shroud comprising: a) a shroud body having a
first inlet opening and a second outlet opening smaller in size
than the first opening, the second outlet opening sized to mate
with an air handling header, the shroud body being made of a
material meeting at least UL standard 94HB; and b) wherein an inner
surface of the shroud disposed between the first inlet opening and
the second outlet openings is non-reflective.
7. The shroud of claim 6, wherein the shroud is made of one of a
polystyrene, a high impact polystyrene, and an ABS.
8. The shroud of claim 6, wherein walls of the shroud forming the
first inlet opening allow for nesting of a plurality of shrouds of
storage purpose.
9. In a method of handling air in a drop ceiling employing an air
handling system header disposed in a space between the drop ceiling
gridwork and a ceiling, the improvement comprising: providing a
grille having a number of air inlet openings therein within a
section of the drop ceiling gridwork, the grille made of a material
meeting at least UL standard UL 94HB or UL standard 181; and
connecting the air inlet openings to an opening in the air handling
system header using a shroud, the shroud having a shroud body with
a first inlet opening, and with a second outlet opening smaller in
size than the first opening, the first inlet opening mating with
the grille, and the second outlet opening sized to mate with an
opening in the air handling header, the shroud body being made of a
material meeting UL standard 94HB, an inner surface of the shroud
disposed between the first inlet opening and the second outlet
openings being non-reflective.
10. The method of claim 9, wherein the drop ceiling gridwork does
not require extra support to support the grille and shroud.
11. The shroud of claim 6, wherein the entire shroud is
non-reflective.
12. The system of claim 1, wherein the entire shroud is
non-reflective.
13. The method of claim 9, wherein the shroud is made of one of a
polystyrene, a high impact polystyrene, and an ABS.
14. The method of claim 9, wherein the grille is made of a
glass-fiber reinforced polypropylene.
15. The method of claim 13, wherein the grille is made of a
glass-fiber reinforced polypropylene.
16. The system of claim 1, wherein the shroud has a section forming
the second opening, an outer surface of the section having a one or
more number protrusions acting as a stop for travel of a portion of
the air handling header when or after being attached to the
section.
17. The shroud of claim 6, wherein the shroud has a section forming
the second outlet opening, an outer surface of the section having
one or more protrusions acting as a stop for travel of a portion of
the air handling header when or after being attached to the
section.
18. The method of claim 9, wherein the shroud is provided with a
section forming the second outlet opening, an outer surface of the
section having one or more protrusions acting as a stop for travel
of a portion of the air handling header when or after being
attached to the section.
Description
[0001] This application claims priority based on provisional patent
application No. 60/391,036 filed on Jun. 25, 2002.
FIELD OF THE INVENTION
[0002] The present invention is directed to an air handling shroud
and grille combination, and in particular, to a shroud made of a
fireproof lightweight material for use in a cold air return
systems.
BACKGROUND ART
[0003] In air handling systems it is common to employ metal boxes
or shrouds to direct air in a desired direction. Metal structures
provide the fire retardancy or fireproofing that is often-times
mandated by local building codes.
[0004] While metal structures allow building codes to be easily
met, installing such structures can be problematic, and
installation costs can be significant. Further, because of the
weight of these structures, installation in drop ceilings requires
support beyond that provided by the drop ceiling grids.
Consequently, additional wiring must be utilized to support the
metal pieces used in the air handling system located above the
ceiling tiles.
[0005] Metal materials in air handling applications are also
undesirable due to their poor corrosion resistance, poor dampening
characteristics (they tend to reflect sound rather than absorb it),
and high reflectivity (they detract from a wall or ceiling
appearance.) Accordingly, a need exists for improved air handling
components that do not suffer from the inadequacies of metal
materials, but are still able to meet building codes requirements,
particularly with regard to resistance to burning.
SUMMARY OF THE INVENTION
[0006] Therefore, it is a first object of the invention to provide
an improved air handling component, particularly a cold air return
shroud for use in a drop ceiling.
[0007] Another object of the invention is a method of handling air
in a drop ceiling that utilizes an air handling component that
lacks reflectivity and is lightweight for ease of installation.
[0008] A further object of the invention is a system and method
that uses the shroud in combination with a grille in a drop ceiling
support structure.
[0009] Other objects and advantages will become apparent as a
description of the invention proceeds.
[0010] In light of the foregoing objects and advantages, the
present invention is an improvement in air handling system
positioned above a drop ceiling grid system and having an air
handling header. The improvement comprises a shroud and a grille,
the grille sized to rest on grid sections forming an opening in the
drop ceiling and being made of a material meeting either UL
standard 181 or UL standard 94. The shroud has a shroud body
forming a first opening that is sized to mate with the grille, and
a second opening sized to mate with the air handling header. The
shroud body is made of a material meeting at least UL standard 94HB
and wherein an inner surface of the shroud disposed between the
first and second openings is non-reflective. The shroud is
preferably made of one of a polystyrene, a high impact polystyrene,
and an ABS, and the grille is preferably made of glass-fiber
reinforced polypropylene. The shroud is preferably configured with
walls and body sections to form a nesting fit when a number of
shrouds are nested together.
[0011] The invention also entails improvements in methods of
handling air in a drop ceiling that uses an air handling system
header disposed in a space between the drop ceiling gridwork and a
ceiling. According to the invention, a grille is provided that has
a number of air inlet openings therein within a section of the drop
ceiling gridwork, the grille made of a material meeting UL Standard
94 or 181. The air inlet openings are connected to an opening in
the air handling system header using a shroud. The shroud has a
shroud body with a first inlet opening and a second outlet opening
smaller in size than the first opening. The first inlet opening
mates with the grille, and the second outlet opening is sized to
mate with an opening in the air handling header. The shroud is
preferably made of a material meeting at least UL standard 94HB,
and an inner surface thereof disposed between the first inlet
opening and the second outlet openings is non-reflective. Because
of the lightweight of the shroud and/or grille, the drop ceiling
gridwork does not require extra supporting hardware.
[0012] While the interior of the shroud is made reflective, the
entire shroud can be made non-reflective. The connector section
forming the second outlet opening can include spaced apart dimples
that protrude outwardly of an outer surface of the connector
section. The dimples act as stops for travel of a rigid takeoff of
the air handling system when being secured to the shroud, or as
stops for travel of a flexible takeoff once attached to the
connector section. The edges of the shroud where body sections meet
are preferably rounded to provide greater impact resistance and
strength.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Reference is now made to the drawings of the invention
wherein:
[0014] FIG. 1 is a side view of the one embodiment of the shroud of
the invention;
[0015] FIG. 2 is a top perspective of the shroud of FIG. 1;
[0016] FIG. 3 is a side view of an alternative shroud
configuration;
[0017] FIG. 4 is a schematic view of the shroud and grille in use
in a drop ceiling structure and an air handling system;
[0018] FIG. 5 is a partial plan view of an exemplary grille for use
with the shroud;
[0019] FIG. 6 is a sectional view along line VI-VI of FIG. 5;
and
[0020] FIG. 7 is a perspective view of an alternative shroud;
[0021] FIG. 8 is a perspective view of an adapter for the shroud of
FIG. 7;
[0022] FIG. 9 is a perspective view of another embodiment of the
shroud of the invention;
[0023] FIG. 10 is a plan view of the embodiment of FIG. 9; and
[0024] FIG. 11 is a cross sectional view along the line XI-XI of
FIG. 10.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] The present invention offers significant improvements in air
handling components, particularly those employed in drop ceilings.
The air handling shroud is made of a material that meets at least
Underwriters Laboratory Standard 94HB. Using this material for the
shroud construction produces a number of benefits beyond the
material's ability to resistance to burning that the UL Standard
specifies. The material is black in color or non-reflective so that
when the shroud is positioned over a drop ceiling grille, light is
not reflected and the ceiling appearance is not compromised by a
view into the shroud itself. The material is also more sound
absorbent that metal material and sound that is typically generated
by air turbulence mechanical, equipment or ambient room noise is
significantly dampened. The material is lightweight so that
additional support of the shroud is not needed when using in a drop
ceiling system. The material is corrosion resistant and does not
rust like metal components.
[0026] FIGS. 1 and 3 show exemplary shrouds as reference numerals
10 and 10'. The shroud 10 of FIG. 1 has a shroud body 1 which
extends between a first opening 3 and a second opening 5. In this
embodiment, the shroud body has four side walls 7, edges 9 of each
wall defining the first opening 3. Four body sections 11 link the
side walls 7 with a cylindrical section 13. The cylindrical section
13 is depicted with a step 15 thus forming a first diameter zone
17, and a smaller diameter zone 19 that terminates in the second
opening 5. The size of the second opening 5 can vary depending on
the air handling application. While a circular opening is depicted,
the body sections 11 could merge into a section with a square or
rectangular cross section, or other cross sectional shape that
would suit connection to an air handling system.
[0027] The first opening 3 is generally the inlet side of the
shroud, and generally faces the area being treated by the air
handling system, e.g., providing a passageway for return of cold
air.
[0028] FIG. 3 shows the alternative shroud configuration 10'
wherein a single section 17' is used to transition from the first
opening 3 to the second opening 5.
[0029] The second opening 5 is adapted to connect to ductwork for
an air handling system such as a cold air return. The attachment
can be by any means such a tape, clips, adhesives or combinations
thereof.
[0030] An exemplary use of the shroud 10' in an air handling system
is illustrated in FIG. 4. The air handling system is a cold air
return system employing a header 21, with a takeoff 23. The takeoff
links or connects with the cylindrical section 17' using any known
means such as adhesives, fasteners, clips, or a combination
thereof.
[0031] The air handling header 21 is disposed above a drop ceiling
system. Two grids 25 of the ceiling system are shown supporting a
grille 27 and tiles 29. An example of the grille design in shown in
FIGS. 5 and 6, but virtually any type of grille or grid that would
meet local building codes can be employed in combination with the
shroud 10'.
[0032] The peripheral edges 31 of the grille 27 rest on the grid
flanges 33. The edges 9 of the first opening 3 of the shroud 10 sit
on the grill 21 and are shown surrounding an upstanding peripheral
wall 35 of the grille 27.
[0033] A partial view of specific grille design is depicted in
FIGS. 5 and 6. The grille 40 has a peripheral flange 41, and a wall
43. The surface 45 of the flange separates the grille peripheral
edge 47 from the grille openings 49. The individual grille openings
49 are formed by the intersecting gridwork 53.
[0034] The shrouds 10 and 10' can be secured to the grille 27 using
any types of fasteners, clips or the like. FIG. 4A shows the use of
a fastening screw penetrating through the walls 7 and 35 to keep
the shrouds secured to the grille 27. However, clips, adhesives,
other types of fasteners or combinations thereof could be employed
to attach the shroud and grille together. In another mode, the
shrouds could merely rest on the grille 27 without the use of any
fastening or attaching means.
[0035] As noted above, the shroud is made of a material that meets
at least the UL 94HB flammability testing. This standard is well
known and a further description is not necessary for understanding
of the invention. In brief, the standard specifies a horizontal
burn rate in terms of mm/min. The UL 94 standard also has a number
of other categories such as V-0, V-1, V-2, SV, 5VB, and 5VA. These
other categories measure other features such as the time in which
burning stops, whether a burn hole is tolerated, etc. The HB
category is the least severe of the categories, and the material
for the shroud and the grille (if the grille is made according to
this standard) should meet at least this category.
[0036] One material that meets this UL 94HB standard is
polystyrene, including high impact polystyrene, commonly referred
to as HIPS. Blending of particulate rubber with polystyrene
improves the impact strength of the polystyrene, thus resulting in
the high impact designation. These rubber modified vinyl aromatic
polymers can be prepared by polymerizing a vinyl aromatic monomer
in the presence of a predissolved rubber to prepare the impact
modified, or grafted rubber containing products. Examples of these
are described in U.S. Pat. Nos. 3,123,655, 3,346,520, 3,639,522,
and 4,409,369, which are herein incorporated by reference.
Conventional high impact polystyrene is available from both The Dow
Chemical Company and BASF Corporation.
[0037] Another material that also meets this standard is NORYL GTX
GTX626 made by GE Plastics. Polyphenylene oxide resins also readily
available from commercial sources, including General Electric
("Noryl" resins). "Noryl GTX" resins, which are alloys of
poly(2,6-dimethyl-1,4-phenylene ether) and a polyamide such as
nylon 6 or nylon 6,6, are also suitable for use as the
polyphenylene oxide component, see U.S. Pat. No. 5,635,556 for
example. This material is more costly than the polystyrene or HIPS,
but it does provide a HDT (heat deflection temperature) of
355.degree. F., whereas a typical HDT value for polystyrene is
183.degree. F. with HIPS having a similar value. Heat deflection
temperature is a relative measure of a material's ability to
perform for a short time at elevated temperatures while supporting
a load. The test to determine the temperature measures the effect
of temperature on stiffness. The test involves giving a standard
test specimen a defined surface stress and the temperature is
raised at a uniform rate. Thus, in instances where resistance to
higher temperatures is required, the GE Plastics material would be
preferred.
[0038] Yet another example of a material meeting the UL 94 HB
standard is an ABS (acrylonitrile-butadiene-styrene copolymer).
This material is similar to the HIPS in that its HDT temperatures
are in the range of 166-201.degree. F. (at 264 psi loading),
depending on the particular type of ABS selected. Primex Plastics
Corporation of Richmond, Ind. offers a number of different types
from a general purpose to a weatherable type (which is
preferred.)
[0039] The grille material can meet either the UL 94 standard,
i.e., at least the 94HB category, or, the UL standard 181.
Underwriters Laboratory (UL) Standard 181 dated Aug. 17, 1981 is
for factory-made air duct materials and air duct connectors,
Section 8, Flame Penetration Test. According to this UL Standard
181, material must not burn through before 30 minutes have elapsed
from exposure to an open flame. An example of a grille material
that meets this specification is a glass-fiber reinforced
polypropylene. These materials, see U.S. Pat. No. 4,379,801 to
Weaver (incorporated by reference) as an example, are known for
their heat resistance and are available commercially from a large
number of sources. Weaver discloses that such a material can have a
heat distortion temperature of 327.degree. F. As with the shroud,
any material that meets the UL standard and can be fabricated into
a grille configuration is adapted for use with the inventive
shroud.
[0040] Referring again to the shroud, it is made so that its
interior surface 45 (see FIG. 4) is non-reflective. This is
accomplished in one mode by the fact that the material used to make
the shroud is black, and all surfaces, including the interior
surface 45 would be black or non-reflective. Alternatively, the
interior surface alone could be made black. Further, and referring
again to FIG. 1, the walls 7 are slightly angled with respect to
the plane of the first opening 3. This allows a number of shrouds
10 to nest together or be stacked vertically/horizontally at a job
site, thus saving space and providing a compact arrangement to
access a shroud for installation. The stackable shroud is vastly
superior to the box like structures used in the prior art which
were not stackable and were not easily stored for installation.
[0041] FIG. 7 shows another embodiment of the shroud as reference
numeral 60, with FIG. 8 showing an adapter 61 for use with the
shroud 60. The adapter 61 reduces the diameter of the opening 63 to
a smaller opening 65 to facilitate connection to an air handling
duct (not shown). For example, if the opening 63 is 12 inches in
diameter, the adapter 61 can reduce the opening 63 to an 8 inch
diameter opening. The edge 67 of the adapter 61 fits over the
opening 63 and the adapter can be connected to the shroud wall 69
using any known means such as fasteners, tape, or the like.
[0042] FIGS. 9 and 10 shows a perspective and plan view of another
embodiment of the invention designated by the reference numeral 70.
The shroud 70 has a rectangular configuration in contrast to the
square configuration of FIGS. 1 and 3, with long side walls 71,
short side walls 73, two long body sections 75, and two short body
sections 77. Similar to FIG. 3, the shroud 70 has a single
connecting section 79 to provide attachment to a takeoff of an air
handling system.
[0043] The connecting section 79 has a number of spaced apart
dimples 85 (two shown). The spacing illustrated is roughly at 90
degrees segments as measured from the center of the section 79.
Other spacings and numbers of dimples can be employed without a
departure from their intended functions. The dimples 85 form a
protrusion in the form of a convex surface on the outer surface 87
of the section 79. The dimples 85 can act as stops when connecting
a rigid or hard takeoff, i.e., a metal takeoff, to the shroud as
shown in FIG. 4. The dimples stop further travel of the takeoff
onto the section 79, such that the takeoff can then be attached to
the section 79 using screws or the like. The distance from the edge
of the section 79 and dimples 85 can vary depending on the overall
length of the section 79, but 1.5 inches is one example of such a
dimension.
[0044] In instances where a flexible takeoff is employed, the
dimples can then act as retaining means to help secure the flexible
takeoff once in place. In this mode, the takeoff can be pushed over
the dimples 86, such that a terminal edge of the takeoff is
positioned between the dimples and the junction of the body
sections 75 and 77 and the section 79. Then, a zip tie or other
non-screw type fastening device can be positioned around a portion
the takeoff below the dimples for securement purposes. The dimples
assist in keeping the zip tie in place by impeding travel over the
dimples, and the takeoff can be attached without the need for
screws or the like. In either instance, the dimples act as stops.
In one mode, the dimples stop or impede travel of the hard takeoff
prior to its securement. In another mode, the dimples stop or
impede travel of the flexible takeoff once it is secured. In an
alternative mode to the dimples, a ridge could be employed that
would extend around the circumference of the section 79 and
function in the same manner as the spaced apart dimples. In this
mode, instead of section 79 having spaced apart protrusions, a
single protrusion extends along the outer surface of the section to
function as the stop.
[0045] As shown in the FIG. 11, the edge 89 between the body
section 75 and 77 is rounded. This provides two advantages over a
sharp edge: the shroud is able to absorb impact better when objects
are dropped on it; and the durability of the shroud is improved,
less tearing at the edges occurs.
[0046] The shroud and grille can be made using any known
manufacturing techniques, including extrusion, molding, stamping,
combinations thereof, or the like. Further, the shroud and grille
can have any dimensions that would interface with the particular
air handling system being utilized. For drop ceilings, the grilles
could be square or rectangular, e.g., 2'.times.2', 1'.times.1', or
1'.times.2'. The shroud opening 3 could match the grille size, and
shroud height could be around 8-10 inches, and the second opening
could be a 6 or 8 inch in diameter. Of course, other dimensions can
be used for the shroud and grille depending on the particular air
handling system.
[0047] In use, the shroud 10 is installed with an air handling
system such as a cold air return. The shroud 10 is sufficiently
light that it can merely rest atop a grille that is positioned in a
drop ceiling grid opening. In this way, additional wires or other
members for shroud and grille support are eliminated and the time
and cost of installing the air handling system components is vastly
reduced. Further, because the inner surface of the shroud is
non-reflective, the space above the grille is not visible to a
person looking at the grille itself and decor of the room below the
ceiling is not compromised as it is when a reflective metal
component is used.
[0048] It should be understood that the shroud and/or grille could
be used in air handling system other than those that are positioned
in ceilings.
[0049] As such, an invention has been disclosed in terms of
preferred embodiments thereof which fulfills each and every one of
the objects of the present invention as set forth above and
provides new and improved air handling system including a shroud
and a grille, particularly adapted for drop ceiling.
[0050] Of course, various changes, modifications and alterations
from the teachings of the present invention may be contemplated by
those skilled in the art without departing from the intended spirit
and scope thereof. It is intended that the present invention only
be limited by the terms of the appended claims.
* * * * *