Note: Descriptions are shown in the official language in which they were submitted.
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THERMAL BARRIER FOR AIR HANDLING UNIT (AHU) CABINET
Feld of the Iavention
'This invention relates generally to a panel fir use in an air handling unit
that
forces a thermal barrier to limit the flow of energy through the panel.
Background of the Invention
Maay air handling units found in the prior art are simply fabricated from
sheet
metal ducts that are connected together in the field to establish an enclosed
flow path,
through which air is conducted The sheet metal walls of the ducts readily
conduct heat
and provide little in the way of a thermal barrier such that energy readily
flows into or out
of the ducts. When the air handling unit is carrying relatively cooled,
conditioned air,
this flaw of energy into or out of the ducts can be costly and places an
unwanted lead on
the sir conditioning equipment.
In addition, when the air handling unit is installed in an unconditioned space
and
is carrying cooled air, the outer casing of the unit will "sweat" due to
condensation of
water vapor in the relatively hot outside air upon contact with the casino.
The moisture
so developed will run off the unit onto the floor or onto equipment contained
in the
unconditioned space. Such run off creates a safety hazard for people working
in the area
and can damage the equipment.
U.S. Patent 5,870,868 discloses an outer panel for an air conditioner. The
panel
dixlosed therein includes an outer peripheral frame formed of four channels
interconnected by four corner blocks, each made of a heat insulating material.
A top
cover and a bottom cover are assembled to the outer wall to define a cavity
that is filled
with an insulating material. The top and bottom covers have flanges that are
received in
channels provided in the outer wall when assembled.
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Summary of the Invention
It is an object of the present invention to improve ducts for conducting air
along a
desired flow path.
A further object of the present invention is to limit the loss of energy
through the
walls of a duct carrying conditioned air.
A still further object of the present invention is to provide an improved
panel for
use in an air handling unit.
Another object of the present invention is to provide a structural panel for
use in
an air handling unit that has a relatively high R value.
Yet another object of the present invention is to prevent ducts of an air
handling
unit from sweating when carrying conditioned air.
These and other objects of the present invention are contained by a panel
suitable
for use in an air handling duct for carrying air along an enclosed path of
travel. The
panel includes a peripheral wall having a top edge and a bottom edge, a top
cover and a
bottom cover. The peripheral wall includes an upper channel opening to the top
edge of
said wall and a lower channel opening to the bottom edge of said wall, each
channel
extending along substantially the entire length of the wall. The top cover and
bottom
cover each have an associated skirt extending about the periphery thereof. The
skirt of
the tnp cover is contained within the upper channel of said wall and the skirt
of the
bottom cover is contained within the lower channel of said wall to establish
an enclosed
cavity within the panel. The peripheral wall further includes an upper grove
opening to
the top edge of said wall and a lower groove openin ; to the bottom edge of
the wall. A
substantially L-shaped bar, a first leg of which is contained within one of
the grooves of
the wall, and a second leg of which possesses a defotmable bulbous section
adapted to
compressively abut in sealing relationship another portion of the air handling
duct such
that air is substantially prohibited from passing into or from the interior
cavity thereby
inhibiting energy transmission.. Advantageously, the cavity may be filled with
a curable
material that sets inside the panel to bond the walls of the frame together
and to bond the
covers to the frame.
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Brief Description of the Drawing
For a further understanding of these and objects of the invention, reference
will be
made to the following detailed description of the invention which is tv be
read in
connection with the accompanying drawing, wherein: ~
>~1g. 1 is a petspoctive view showing a section of ductwork for conducting air
along a desired flow path with a panel shown removed from the support frame of
the ductwork; ~
Fg. 2 is as enlarged per$pective view of a panel employed to enclose the
support
frame of the ductwork illustrated in Fg. 1;
3;
Ft& 2;
Fg. 3 is an exploded view illustrating the panel frame and covers;
Ftg. 4 is an enlarged~sectional view of the panel frame taken along line 4-4
in Fg.
Fg. 5 is as enlarged sectional view of the panel assembly taken along lines 5-
5 in
Fig. 6 is an enlarged partial view showing a corner section of the ductwork
skeleton with one panel removed from the duct work;
Ftg. 7 is a view similar to Fg. 6 showing the panel locked to the ductwork
skeleton;
Fg. 8 is as enlarged view showing the latching mechanism far locking a panel
to
the ductwork skeleton in a retracted position;
Fg. 9 is similar to Fig. 8 showing the latching mechanism in a raised locking
position;
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Fg. 10 is an enlarged sectional view of the panel asstmbly taken along the
lines
10-10 in 1~sg. 1;
>~ig. 11 is a top schematic illustration of the panel asstmbly in the left
most
region of the ductwork shown in Fig. 1 with the panels oriented in a side-by-
side
ataangement along the ductwork frame;
F g.12 is a schematic illustration similar to that shown in Ftg. l l with one
of the
panda hingedly mounted to the frame and rotatably extending is an open
position
relative to the frame; and
1=ig.13 is a xhetnatic illusication similar to F g. l l showing as unhinged
panel
tr,.moveably positioned away from the frame.
)Detailed Des~ip~on Of A Pretetrred Embodiment
'Ltle following description of a preferred embodiment is for the Purpose of
explanation, and not limitation. Soma specific details are set forth in order
to provide a
)understanding of a preferred embodiment of the present invention, however, in
otbacinstauces, description of other elements, features, and ttchaiques are
omitted so ss
not to encumber or confuse the reader with unnecessary detail. It will be
appattnt to
one skilled in the art that the present invention may be practiced in other
embodiments
that depart from the following description and that differences may exist from
the
embodiment specifically described without departing from the spirit and scope
of the
present invention. The following detailed description is therefore not to be
taken in a
limiting sense.
'Ihe present invention will be described with reference to the accompanying
drawings, wherein like reference numerals refer to the same item. Turning
initially to
Ftg. 1 there is illustrated a section of an air handling unit (AHin, generally
referenced
10, that employs wall panels 12 embodying the teachin gs of the present
invention. The
air handling unit is composed of a series of rectangular shaped modules tech
of which
possess a superstructure including a pair of rectangular, planar end frames 13
and 14
that are connected at the corners by a pair of horizontally disposed upper
beams 15 and
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a pair of horizontally disposed lower beams 16. Each end frame includes a pair
of
opposed side rails 17 and 18 and an upper rail 20 and a lower rail 21. In
assembly, the
rails and the beams are retained slidably in corner pieces 23. The rails and
the beams in
assembly thus establish an open skeleton having rectangular openings.
As will be explained in greater detail below, wall panels embodying the
teachings of the present invention can be placed in the skeleton openings to
close the
AHU sections. Each panel is constructed so that it has an extremely high
insulation
value, thus greatly impeding the flow of heat into or out of the unit which,
in turn,
prevents the unit from sweating.
With further reference to Fig. 2-5, each panel 12 includes a rectangular frame
25
having a pair of opposed side walls 27 and 28 and a pair of opposed end walls
29 and
30. Each wall contains mitered ends so that the walls can be brought together
to form
right angle corners. Each wall is molded of a plastic material having a high
insulation
value and low thermal conductivity. As best illustrated in Fig. 4, each wall
contains a
vertically disposed wall partition 31 having a rectangular shaped recess 32
formed
centrally therein that extends along the length of the partition. The recess
32 is inwardly
disposed with reference to the outer surface of the partition 31. An upper tab
33 and a
lower tab 34 are integrally molded on the inside of the partition 31 on either
side of the
recess 32. The tabs 33, 34, like the recess 32, extend along the length of the
wall. The
tabs 33, 34 run parallel to the partition 31 and coact therewith to form
narrow channels
35 and 36. The upper channel 35 opens towards the top of the wall while the
lower
channel 36 opens toward the bottom ofthe wall. A flange 38, which is integral
with the
wall partition 31, runs along the top edge of the partition 31. The flange 38
extends
outwardly from the wall partition 31 and forms an angle that is slightly less
than 90°
with the partition 31 so that the flange 38 extends downwardly at a slight
angle from the
top edge of the partition.
As illustrated in Fig. 5, a top cover 40 and a bottom cover 41 are used to
close
the frame and create a cavity inside the panel. Each cover 40, 41 contains an
inwardly
directed skirt 45 that depends downwardly from the cover and extends around
the entire
periphery of the cover. In assembly, the skirts 45 are inserted into the upper
and lower
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channels that encircle the panel frame. A curable foam 43 is injected into the
cavity to
entirely fill the cavity with the foam. When the foam cures, it bonds the
frame walls
together in abating contact and bonds the covers to the frame. Preferably, the
curable
foam is a polyurethane material which like the panel frame walls has a high
insulation
value.
Each panel is sized so that the panel frame can be slipped into an opening in
one
of the unit sections. A close sliding fit is provided between panel frame
walls and the
side rails and upper and lower beams that form the receiving opening. When the
panel
is fully received within the opening, the flange 38 that surrounds the panel
frame is
compressed against the outer surfaces of the rails and beams forming the
opening.
As illustrated in Fig. 6 and 7, compressible hollow seals 50 are preferably
mounted around the panel receiving opening. At panel closure, the lower cover
41 of
the panel compresses the seals as shown in Fig. 7 to prevent air inside the
unit from
escaping around the panel.
The panels are held in a closed position by a series of latching mechanisms,
generally referenced 60, that are mounted inside the rails and the beams
surrounding
each opening. Preferably, the rails and the beams are squaxe metal tubes that
axe
slidably retained in the corner pieces. Each latching mechanism includes a
cylindrical
tumbler 62 that is retatchably contained within the tube 63. The tumbler
contains an
outer flange 64 (see Figs. 8 and 9) that has a six sided slot 65 that passes
inwardly
through the flange. An Allen wrench 67 is insertable into the slot and is used
to turn the
tumbler between an open position and a locking position. An elongated arm 70
is
secured to the tumbler that is arranged to pass upwardly through a slotted
hole 69 in the
containing tube as the tumbler is turned from an open position as illustrated
in Fig. 8 to
a locking position as illustrated in Fig. 9. The arm 70 is arranged to pass
into the recess
32 surrounding the panel frame and to force the panel into sealing contact
against the
seals 50 surrounding the panel receiving opening as shown in Fig. 7.
Preferably, at least
one latching mechanism is employed to engage each of the walls making up the
panel
frame 25.
There is shown in Fig. 10 a partial sectional view of two panels oriented in a
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side-by-side arrangement along the framework. Each of the panels is
essentially
identical to the panels previously described, in addition, each peripheral
wall of the
panel facing the peripheral wall of the adjacent panel possesses a generally U-
shaped
groove 90 associated with the channel. As best shown in Fig. 10, each groove
90
extends generally parallel to an associated one of the channels in the wall
and is
disposed peripherally outwardly from the associated channel. Also, the depth
of each
groove 90 is substantially shorter than the depth of the associated channel,
approximately one-quarter to one-half ofthe depth ofthe associated channel.
Preferably
each groove 90 is formed by integrally molding the groove 90 with the wall.
In the embodiment shown in Fig. 10, at least one of the panels includes a
substantially L-shaped bar 92 having a first leg 94 adapted to abut an
associated one of
the channels and to extend into the associated groove 90. The first leg 94
includes a leg
or boss 95 adapted to abut the upper edge of the associated groove 90 and is
adapted to
act as a stop. The L-shaped bar 92 also includes a second leg 96 which
preferably
possesses a resiliently deformable bulbous section 98 adapted to compressably,
sealingly abut with the cover of an adjacent panel, as best shown in Figs. 10
and 11.
Preferably, the bulbous section 98 is fashioned in a tubular configuration
having a
hollow core. It should be appreciated that the second leg 96 may possess
deformable
and resiliently deformable configurations other than a bulbous shape. Also,
the
remaining portion of the L-shaped bar 92, other than the bulbous section 98,
is
preferably rigid, and preferably the entire L-shaped bar 92 is fashioned as a
dual
durometer bulb seal. Preferably the L-shaped bar 92 extends along the entire
length of
the interface between the two opposing walls of adjacent panels.
As best shown in Figs. 10 and 11, the bulbous section 98 substantially
prevents
air from flowing between the interior and the exterior of the duct, that is,
prevents air
from flowing through the region between the opposing walls adjacent panels.
In a non-deformed, rest state, the bulbous section 98 preferably possesses a
substantially elliptical cross-section, as best shown in Figs. 12 and 13.
Although the
bulbous section 98 is preferably tubular and possesses a hollow core, with
open ends,
the present invention contemplates that the bulbous section may be tubular
with closed
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ends and may be filled with a fluid. Also, the core of the bulbous section 98
may be
filled with a deformable solid such as a foam rubber or other elastomer. Also,
the
bulbous section 98 may not have any core section, but rather, may be fashioned
from a
unitary piece of material such as a foam rubber or other elastomer. In
addition, the
bulbous section 98 may be fashioned of a material that is discrete from the
material
from which the remainder of the L-shaped bar 92 is fashioned, and for example,
the
bulbous section 98 may be adhered to or otherwise secured to the remaining
portion of
the L-shaped bar 92.
The L-shaped bar 92 may be releasably fastened to the associated panel by the
provision of a screw 100 extending through the first leg 94 of the L-shaped
bar 92,
through the associated channel and cover skirt, and into the foam insulation,
as best
shown in Fig. 10. Although the L-shaped bar 92 is mounted to the wall of the
associated panel by the insertion of the first leg 94 into the associated
groove 90 and by
the screw 100, it is within the scope of the present invention that other
designs may also
be used effectively, such as integrally forming the L-shaped leg 92 with the
wall,
adhering the L-shaped leg 92 to the wall, and clipping the L-shaped bar 92 to
the wall.
Alternatively, in utilizing L-shaped bar 92, the first leg 94 may extend
substantially
parallel to the second leg 96, with the second leg mounted on the cover 41 of
the
associated panel. It should be appreciated that although the L-shaped bar 92
is
preferably selectively, releasably mounted to the associated panel, it is
within the scope
of the invention that the bar 92 may be fixedly mounted to the panel.
Referring to Figs. l l and l2,hinged wall panels 114 may be used instead of
wall
panels 12 when easy access to the interior of AHU 10 is required. A latch
holds hinged
wall panel 114 closed by interacting with a side piece 18 Or another latch on
an
opposing wall. Hinged wall panel 114 includes a living hinge 122 which in turn
includes a mounting flange 124 for mounting panel 114 onto side piece 18, a
hinge
portion 126 which bends without breaking, and an edge extrusion 128 which
connects
living hinge 122 to a panel perimeter. A seal 50, preferably hollow and
compressible, is
affixed to side piece 18. When wall panel 114 is closed, panel 114 compresses
seal 50
to form a sealing fit with side piece 18.
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While the present invention has been particularly shown and described with
reference to the preferred mode as illustrated in the drawing, it will be
understood by
one skilled in the art that various changes in detail may be effected therein
without
departing from the spirit and scope of the invention as defined by the claims.
