Note: Descriptions are shown in the official language in which they were submitted.
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ADAPTABLE EXHAUST BOX
TECHNICAL FIELD
[0001] The invention relates to an exhaust box for
mounting in the exterior wall of a building to exhaust air
from building ducts through the exterior wall.
BACKGROUND OF THE ART
[0002] The rooms of residential, commercial and
industrial buildings are exhausted and air circulated using
various fans, blowers and are ducts. Moisture,
contaminated air and dust are drawn from rooms and conveyed
through ducts to roof vents or exhausted through exterior
walls.
[0003] Conventional ducts used in residential buildings
are cylindrical or rectangular tubes made of sheet metal,
flexible corrugated metal or plastic. In the present
description and drawings only cylindrical ducts are used as
an example, however it will be understood that the
invention can accommodate any conventional duct type to
equal advantage.
[0004] Conventional exterior wall exhaust boxes are
mounted in an exterior wall through an opening in the wall
structure, through a portion of a window frame or an upper
part of a door frame. The exhaust boxes may be difficult
to access after construction and therefore long term
maintenance-free service is important.
[0005] For example, high rise apartments or condominiums
may have exhaust boxes through walls many stories above the
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ground that exhaust bathrooms and kitchens of the high rise
unit. Moisture laden air exhausting outdoors will result
in water condensation on colder surfaces of the exhaust
box.
[0006] Excessive condensation will enable mildew, mold
and even fungi to grow within the exhaust box and adjacent
ducts. Such growth absorbs even more water causing metal
corrosion. Fungal and mold spores create a health hazard.
Runoff of precipitation that enters the exhaust box can
cause staining of the adjacent building wall. Excessive
growth can interfere with check valves or seals that
prevent outside air inflow into the building ducts.
Therefore prevention of moisture buildup is an important
goal of exhaust box design.
[0007] It is preferable to have the least number of wall
openings in a building as possible, to minimize air
infiltration and insulation problems. Typically an
apartment or condominium unit will have a kitchen exhaust
fan over the stove and exhaust fans in each bathroom. The
number of ducts and sizes of ducts that join to the exhaust
box may vary considerably. For example, ducts of 4, 5 or 6
inch diameter may be commonly used in a single dwelling
unit and the number of bathrooms varies resulting in
between 1 to 4 ducts joining to a single exhaust box.
[0008] Conventionally, due to the variety of possible
combinations of duct sizes and numbers, exhaust boxes are
manufactured to order. Contractors and purchasers must
specify the number of ducts, the duct diameters and the
specific order in which ducts are arranged. If mistakes
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are made in ordering exhaust boxes, or if changes are made
during construction, the conventional exhaust boxes cannot
be easily modified on site. Changes to the ducting and
exhaust boxes results in significant construction delays,
increased costs and wasted materials.
[0009] Therefore it is desirable to have a wallbox
design that is adaptable to the inevitable changes that
occur during construction, simple enough to fabricate on a
very short notice and of standard components to minimize
the inventory required by a manufacturer.
[00010] Features that distinguish the present invention
from the background art will be apparent from review of the
disclosure, drawings and description of the invention
presented below.
DISCLOSURE OF THE INVENTION
[00011] The invention provides an air exhaust box, for
mounting in an exterior building wall and connecting to at
least one exhaust duct, includes: a housing having side
walls, a rear wall and a front exhaust opening; the front
opening having a mounting flange surrounding a periphery of
the opening and extending outwardly from the side walls;
the rear wall having an inlet opening greater than a
predetermined maximum dimension; each of the side walls
being joined to the rear wall at an angle less than 90
degrees; and a duct adapter having a cover removably
mountable to the rear wall with removable fasteners, the
cover having an outer dimension larger than said maximum
dimension of the inlet opening and a rearwardly projecting
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duct sleeve with an inner opening of size between said
maximum dimension and a minimum dimension.
DESCRIPTION OF THE DRAWINGS
[00012] In order that the invention may be readily
understood, one embodiment of the invention is illustrated
by way of example in the accompanying drawings.
[00013] Figure 1 is a perspective view of the front-top
of an exhaust box with three inlet openings and showing
three adapters with three different diameter sized duct
sleeves.
[00014] Figure 2 shows the exhaust box of Fig. 1 in a
vertical position to indicate that the exhaust box can be
installed with any sloped side wall downward.
[00015] Figure 3 is a front view of the exhaust box of
Fig. 1 showing the front flange and rear wall with three
inlet openings separated by baffle walls.
[00016] Figure 4 is a side view of the exhaust box
showing the insertion of the adapter with duct sleeve
extending rearwardly through the inlet opening.
[00017] Figure 5 is a perspective view of a three opening
exhaust box with three adapters of equal size.
[00018] Figure 6 is a perspective view of a two opening
exhaust box with two adapters of equal size.
[00019] Figure 7 is a perspective view of a single
opening exhaust box with a single adapter.
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[00020] Figure 8 is a side view, similar to Fig. 4, of an
alternative embodiment of the exhaust box showing only the
lower long side wall as sloped and the upper long side wall
as horizontal.
[00021] Figure 9 is a side view of the alternative
embodiment of the exhaust box showing only the lower short
side wall as sloped and the upper short side wall as
horizontal, with baffle walls also sloped to shed moisture
accumulation.
[00022] Figure 10 is a front view of the alternative
embodiment of the exhaust box to show the sloping baffle
walls and overlapping corner portions of the walls that
form the front flange.
[00023] Figure 11 is a plan view of flat sheet metal
blanks used to form a two opening version of the exhaust
box such as shown in Fig. 6, using the drawing convention
that solid lines indicate cuts, dashed lines indicate
upward folding lines and dash-dotted lines indicate
downward folding lines.
[00024] Further details of the invention and its
advantages will be apparent from the detailed description
included below.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[00025] Figure 1 shows a perspective view of a front top
of an exhaust box 1 which has three inlet openings 2.
Figure 1 also shows three different sized adaptors 3, 4, 5,
namely a four inch diameter adaptor 3 a five inch diameter
adaptor 4 and a six inch diameter adaptor 4. Each of the
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three adaptors 3, 4, 5 has a different size duct sleeve 6
to suit different diameters of exhaust ducts 10.
[00026] Inlet openings 2 in the rear wall 14 are sized
for a maximum dimension, for example 6 1/8 inch inside
diameter, such that the largest 6 inch outside diameter
adaptor 5 can fit in any one of the inlet openings 2, and
the other smaller adaptors 3 and 4 can also be mouonted
through any opening 2. Accordingly, the inlet openings 2
are all standardized to have a maximum diameter size (ex.
6.125 inch) and the adapters 3, 4, 5 are standardized with
mounting screw holes 8, 9 having varying sizes of duct
sleeves 6 on which cylindrical exhaust ducts 10 can be
mounted. In the embodiment shown, the adapters 3-5 can be
attached in position within the inlet opening 2 by
installing removable screw fasteners 7 through aligned
pre-drilled holes 8 and 9.
[00027] The forward portion of the air exhaust box 1 is
mounted in an exterior building wall, a door frame or
window frame (not shown) and a rear portion of the sleeves
6 connect to at least one exhaust duct 10.
[00028] Figure 2 illustrates the exhaust box 1 of Fig. 1
but oriented in a vertical position to indicate that the
exhaust box 1 can be positioned with any one of the side
walls 12-13 in a downward position. Since all side walls
12-13 are sloped or tapered towards the front exhaust
opening 15, in any orientation of the box 1, moisture can
drain forwardly out of the box 1.
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[00029] The assembled air exhaust box 1 is comprised of
the generally rectangular housing 11 and multiple duct
adapters 3, 4 and 5. It will be understood that the number
of inlet openings 2 and adaptors 3, 4 and 5 depend entirely
on the specific installation and the housing can have 1 to
4 different inlet openings 2, for example, with different
sized adaptors 3-5 to suit any installation. Experience
with residential exhaust systems shows that anywhere from 1
to 4 exhaust ducts is not unusual, but it will be
understood that the invention is not restricted to any
number or size of duct adapters 3-5.
[00030] As best seen in Figures 3 and 4, the housing 11
in the illustrated example has trapezoidal shaped sidewalls
namely long sidewalls 12 and short sidewalls 13. The
complete housing has a rear wall 14 and a front exhaust
opening 15 to which the side walls 12-13 connect.
Conventional galvanized sheet metal cutting, bending, spot
welding and fastening methods can be used and need not be
explained in detail.
[00031] The front exhaust opening 15 has a rectangular
mounting flange 16 surrounding the periphery of the front
exhaust opening 15 and the flange 16 extends a short
distance outwardly from the side walls 12 and 13. The
flange 16 is used to reinforce the front opening 15 as well
as provide a flush surface for installation and sealing to
the exterior of the building wall.
[00032] The rear wall 14 has inlet openings 2 that are
greater than a predetermined maximum dimension. In the
example illustrated, the maximum dimension is 6 inches, the
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outer diameter of the largest adaptor 5 sleeve 6, and the
opening is 6.125 inches to provide adequate clearance.
[00033] As best seen in Figure 4, Figures 1 and 2, each
of the side walls 12 and 13 is joined to the rear wall 14
at an angle less than 90 degrees, by bending a sheet metal
blank for example to form the flange 16. Figure 4
illustrates the angle a indicating that the side walls 12
and 13 are all sloped in a generally trapezoidal shape.
This sloping of all sidewalls 12-13 enables moisture, from
condensation of the exhaust air and from infiltration of
precipitation, to drain towards the front exhaust opening
and then be expelled from the building.
[00034] Further, moisture from within the exhaust housing
11 cannot penetrate into the adjacent insulation or
15 building materials since the edges between sidewalls 12-13,
flange 16 and rear wall 14 are bent from sheet metal blanks
or are otherwise water sealed with caulking, gaskets or
water resistant coatings. The interior surface of the
exhaust box 1 can be coated with mold and mildew resistant
herbicidal compounds to reduce the risk of contamination.
[00035] As indicated in Figures 1 and 2 because all four
walls, namely the long side wall 12 and short side walls
13, are equally tapered, any one of the walls 12 or 13 can
be positioned during installation in a down position
without risk of moisture build-up. This orientation need
not be specified when ordering the wall box 1. Further,
the tapering of the side walls 12 or 13 enables the
manufacture to stack or nest the housings 11 during
manufacture to the minimize storage space required.
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[00036] As seen in Figures 1 and 4, each duct adaptor 3,
4 and 5 has a cover 17 that is mounted to the rear wall 14
with removable fasteners such as screws 7. The cover 17
has an outer dimension larger than the maximum dimension of
the inlet openings 2 in order to cover the openings 2 in a
generally air tight manner. A gasket or caulking could be
positioned between the cover 17 and the rear wall 14 to
seal against moisture and air penetration if desired. The
rearwardly projecting duct sleeves 6 have an inner opening
of size selected between the maximum dimension of the inlet
openings 2 and a minimum dimension to fit on various sized
exhaust ducts 10.
[00037] Figures 5, 6 and 7 show various arrangements
which are possible using the invention. Figure 5 shows a
perspective view of a three-opening exhaust box housing 11
with three adaptors 5 all of equal size. Alternatively,
Figure 6 shows a perspective view of a two-opening exhaust
box housing 11 with two adaptors of equal size 5. Figure 7
shows a single opening exhaust box housing 11 and a single
adaptor 5. It will be understood, that the adaptors 5 can
be selected of any size and the duct sleeves 6 can be
fabricated to suit various sizes of ducts 10. The
manufacturer can stock pre-fabricated housings 11 and
adaptors 3, 4, 5 of various sizes and numbers of openings
in order to quickly assemble and shipped any combination of
number of openings and size of openings to builders.
Further, if any changes are required during construction,
it is a simple matter to exchange the adaptors 3, 4, 5 even
after the housing 11 has been fully mounted and sealed with
adhesive caulking to the building wall.
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[00038] Therefore the builder can make changes to the
ducting simply by exchanging or by relocating the adapters
without removing an installed housing 11 from the exterior
wall of the building. During construction, especially in
cold or wet climates, closing in a building against weather
is a primary concern. The flexibility to change adapters
3-5 after mounting a housing 11 simplifies manufacture,
purchasing and installation while increasing the speed at
which exhaust box 1 orders can be shipped to a purchaser
from a manufacturer.
[00039] When multiple openings 2 are used, a baffle wall
18 may be used to extend between the adjacent inlet
openings 2 from the rear wall 14 to the front exhaust
opening 15. The baffle walls 18 prevent exhausted air from
one duct 10 mixing with and being conducted into another
duct 10 rather than exhausting from the building. The
baffle walls 18 therefore prevent back flow of exhausted
air and direct exhausted air through the opening 15 rather
than risking exhausted air from being directed into the
building by strong winds.
[00040] As best seen in Figures 1 and 4, the adaptors 3,
4 and 5 can include a forwarding projecting rectangular
frame 19. The frame 19 serves to reinforce the cover plate
17 as well as provide vertical walls into which checkvalve
flap or other back flow preventive measures may be mounted
in a removable manner. By using the frames 19, it is
possible to mount a checkvalve flap for example in a manner
that can be easily removed, repaired or exchanged, if
necessary. Further, the manufacturer can adapt different
flaps to suit the frames 19 if desired.
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[00041] As best seen in Figure 4, the flange 16 on the
front of the housing 11 comprises a vent over a front lip
portion of each side wall 12 and 13. The lip portions are
joined to adjacent lip portions in an overlapping corner
joint which is either spot welded or otherwise sealed
together in a unitary flange 16. The flange 16 provides
means to abut building structure such as a window or a door
frame or onto brick or other exterior surfaces. The flange
16 can be secured with caulking or a gasket to prevent
moisture penetration.
[00042] Therefore, the wall boxes 1 provide a flange 16
that can be assembled to the wall in a leak-proof manner.
Optional internal divider baffle walls 18 separate the
airflows and ensure that back flow of exhausted air does
not occur. Condensation is dealt with by providing four
side walls 12 and 13 each with an outwardly directed taper
to drain properly towards the outside surface. The exhaust
box components are preferably made of galvanized sheet
metal to prevent rust from moisture and weather exposure.
The flange 16 is continuous and provides a weather barrier
to engage with caulking and sealants. Pre-drilled holes 8
and 9 provide screw fasteners 7 with simple and accurate
means for mounting adaptors 3-5.
[00043] Figure 8 shows a side view, similar to Fig. 4, of
an alternative embodiment of the exhaust box 1 showing the
lower long side wall 12 as sloped at angle a and the upper
long side wall 12 as horizontal, oriented 90 degrees
relative to the rear wall 14. Figure 9 is a side view of
the same alternative embodiment of the exhaust box 12
showing the lower short side wall 13 as sloped at angle a
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and the upper short side wall 13 as horizontal, oriented 90
degrees relative to the rear wall 14, with baffle walls 18
also sloped to shed moisture accumulation. Figure 10 is a
front view of the alternative embodiment of the exhaust box
1 to show the sloping baffle walls 18 and overlapping
corner portions 20 of the walls 12-13 that form the front
flanges 16. This alternative configuration permits the
exhaust box 1 to be used in horizontal and vertical
orientation with the sloped side downward to shed moisture
accumulation.
[00044] Figure 11 is a plan view of flat sheet metal
blanks used to form a two opening version of the exhaust
box. A drawing convention is used where solid lines
indicate cuts, dashed lines indicate upward folding lines
and dash-dotted lines indicate downward folding lines.
Upper and lower side wall blanks 21 are shown trapezoidal
to form slopes on both long side walls 12 and with a
downwardly bent flange 16 including overlapping corner
portions 20 (as in Figs 1-7). The short side walls 13 can
be cut rectangular, then mounted outwardly of the rear/long
side wall upward bent edges and extended beyond the edge
connection with a long side wall in order to provide side
wall extensions to mount the box level in a building wall.
Rear and long side wall blank 22 is shown rectangular to
form 90 degree corners with both short side walls 13 and
with a downwardly bent flange 16 including overlapping
corner portions 20.
[00045] The overlapping portions 20 reinforce the corners
of the flange 16 and ensure that flange 16 is continuous to
seal and mount the box 1 in a building structure. The
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flange 16 and flat walls may be used to mount and contain
insulation materials.
[00046] Accordingly, the invention provides a very
flexible system which reduces the time in which orders are
required for processing by a manufacturer. Conventional
exhaust boxes are custom made to order and are not
adaptable if any changes are required during construction.
In contrast, the invention provides complete flexibility
using standard components and reduces the variety of boxes
which the manufacturer must keep in inventory.
Accordingly, rapidly deployed shipments result from the use
of the invention. The adaptors 3, 4 and 5 can be stocked in
a manufacturer's facility and assembled when orders are
received for housings 11 with 1 to 4 openings to suit
almost any required building construction situation.
[00047] Although the above description relates to a
specific preferred embodiment as presently contemplated by
the inventor, it will be understood that the invention in
its broad aspect includes mechanical and functional
equivalents of the elements described herein.
