Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
ADJUSTABLE AIR I~LET BAFFLE STRUCTU~E
In agricultural buildings such as hog sheds, chick~
en houses, or the li~e, ventilation systems must be provided
to exhaust the stale inside air and supply fresh air from the
exterior. The most common design for such a ventilation sys
tem is one which incorporates a negative pressure type ven-
tilation, that is, the inside air is drawn out of the buil-
ding by exhaust fans, and exterior air is allowed to enter
through openi~gs usually located near the ceiling. Entrance
of the exterior air is not forced, but occurs because of the
decrease in pressure in the inside of the building caused by
the removal of some of the interior air by the exhaust fans.
It is most desirable in such a system to have some adjustable
means, such as a baffle over the opening, for the exterior
air so that entrance of the exterior air may be regulated and
directed upwardly or downwardly in the building space. De-
pending upon the temperature of the exterior air, the number
of animals in the building, or other factoxs, it is desirable
to restrict the opening for exterior air and direct the air
along the ceiling from where it will gradually settle within
the building~ This is especially so during cold weather when
it is importa~t to allow the cold entering air to be warmed
before it r~aches the animals housed within the building.
Without the ba~fle, large amounts of cold air will settle
directly under the opening, causing an excessively cold spot.
The baffle ~irects ~he incoming air so as to more evenly dis-
perse it throughout the building.
One of the principal problems encountered in this
type of system is due to the diference in temperature be-
tween the exterior air and the interior air. During the win-
tertime, the passa~e of the generally cooler exterior airover the baffle cools the surfaces of the baffle, and when
these cooler suraces are contacted by the warm and humid in-
terior air, condensation occurs. This can cause :Erosting on
2.
the baffle which may accumulate onto the walls and ceiling,
and in turn may remelt, thereby causing excessive moisture
to collect in these areas and resulting in many moisture
related problems. The hinges on the baffle which provide
the adjustability may become completely frozen over, there-
by preventing adjustment of the baffle. In such instances
the baffle must either be left in its frozen position or
the hinges must be cleared of ice. It is therefore one of
the principal objects of the present invention to proviae
an adjustable air inlet baffle structure for an agricul-
tural building ventilation system, which directs the flow
of incoming air and which reduces the occurrence of con-
densation and frost build up by substantially eliminating
the situation where warm and humid inside air contacts a
baffle surface cooled excessively by the incoming air, there-
by making the system more reliable and efficient in cold
weathar.
Another object of the present invention is to
provide a baffle for an agricultural building ventilation
system which is fully adjustable even in very long lengths,
but which does not require the use of metal hinges or other
devices which may ~reeze, rust or stick, and which thereby
minimizes maintenance requirements to keep the baffle in
optimum operating condition.
Still another object of the present invention is
to provide a baffle for an agricultural building ventilation
system which may be installed in a variety of ways so as to
direct the flow of incoming air either across the ceiling
or down a wall, and which is light in weight and simple in
design so as to make installation quicker and easier, and
which, because of its light weight, may be manufactured
and installed in longer lengths, thereby reducing the number
of joints which must be made when such a system is installed
in a long building, thus minimizing the possibility of air
leaks.
o~
Generally, the present inventlon provides an
adjustable air inlet baffle structure for the air inlet vent
of a building ventilation system comprising elongated walls
of plastic material forming an outer shell with an inner area
defined by the walls, a substantially rigid insulating board
disposed in the area and providing rigidity to the baffle and
flexible hinge means of plastic material joining integrally
to the shell along one edge thereof.
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Further objects and advantages of the present
invention will be obvious from the following detailed
description and drawings wherein:
Figure 1 is a perspective view of a portion of
an agricultural huilding, with the end exterior wall re-
moved, and showing the baffle of the present invention
installed;
Figure 2 is a perspective view of a baffle such
as that shown installed in Figure l;
Figure 3 is a perspective view of the interior
of an agricultural building showing the baffle and one
means of adjusting the baffle;
Figure 4 is a vertical cross sectional view of
the baffle shown in Figure 2, the section taken on line
4 - 4 of Figure 2; and
Figure 5 is an enlarged cross-sectional view of
one portion of the baffle shown in Figure 4.
Referring more specifically to the drawings,
and to Figure 1 in particular, numeral 10 indicates an
agricultural buildiny employing the ventilation system
and baffle of the present invention. The building has a
roof 12 supported by rafters 1~ and joists 16. The ceil-
ing 18 is attached to the underside of the joist and to
headerboards 20 disposed between and attached to the rafters
at a point spaced inwardly from wall 22. A screen 28 is
disposed in the underside of the eave of roof 12, which
is closed on its end by a facia board 29. A closure board
30 is attached to a soffit board 31 by a plurality of
hinges 32, and is used to control the air flow th~ough the
openlng of screen 28~ either to completely close or to
substantially restrict the ventilation system, particularly
during extremely cold weather. The ceiling 18 is spaced
from wall 220 terrni.nating at heade.rboard 20 a short distance
from the interior wal], thereby forming an opening 3~ for
entrance of the fresh air. Likewise, headerboards 20 do
not extend upwardly completely to roof 12 but are spaced
therefrom to form an air passage 36 to permit the air to
flow from the space between the roo and ceiling into the
ventilation system.
A baffle 38, having a flexible hinge strip 40,
is attached to interior of wall 22 by a plurality of nails
41, and directs the flow of the incoming air through space
34 along the underside of ceiling 18. Flexible strip 40
is made o~ a pliable plastic material, such as vinyl, which
provides the hinge-like action required in adjustment of
the baffle. This strip is integrally attached along the
length of the baffle, preferably near the upper longitudinal
corner thereof, and during installation is nailed or skapled
to the inner wall structure of the building near the upper
edge thereof. The walls of the baffle consist of relative-
ly rigid but flexible plastic sheet material 42, such as
vinyl, surrounding a substantially rigid insulation board
44 preferably of styrofoam or polystyreme material. This
insulation material minimizes the transfer of heat between
the upper and lower sur~aces of the baffle, and in doing
so reduces the amount of condensation which would normally
occur in the conventional type o~ ventil~tion baffle. The
cold air passes over the upper surface of the baffle, and
that surface remains cold while the insulation material
prevents the heat from the lower surface from being trans-
mitted to the upper surface and prevents the cold air from
cooling the warmer lower surface, thus minimizing conden-
3Q sation and frost on the lower surace.
In the typical installation, adjustment of the
ba1e is accomplished by a winch similar to that indicated
by numeral 46 in Figure 3. Any suitable wind-up or cran~
device may be used, with a main adjustment line 48 o rope
or light cable passing therefrom through appropriate pulley
blocks 50 and eye bolts 52 secured to the joist near the end
thereof. An attachment line 54 is affixed to baffle 38 by
a fixture 55 and extends upward and through an eye bolt 52,
and is attached to main line ~8 by clamps 56 and 58. De-
pending on the length of the baffle r several attachment
lines may be re~uired, and a counterweight 60 is preferably
attached to the end of main line 48 to facilitate operation
of the baffle control mechanism. In the installation shown,
a gusset 62, through which main adjustment line 48 passes,
is installed at the end of the baffle. Due to the relative-
ly light weight of the material of the baffle, the various
components of the adjustment system, such as the winch,
line, rope or cable, may also be of a lighter design~ By
adjustment of crank 46, the opening 34 between khe upper
inside edge of baffle 38 and ceiling 18 may be widened or
narrowed, thereby regulating the flow of incoming air.
In the use and operation of the adjustable baffle
in a ventilation system, as shown in Figure 1, the baffle
sections are attached by nailing or stapling flexible stri~
40 onto the wall as illustrated in Figures 1 and 3. Because
of the light weight of the plastic and polystyrene baf~le,
installation can be made with small nails or staples, thus
greatly facilitaking installation, expecially when a staple
gun is used. The polystyrene insulation section of the
first baffle section installed is cut in half. The poly-
styrene section of the adjacent baffle is then slid so that
half of it is in the first baffle section and half in the
second baffl~ section. In this way the first and second
baffle sections are connected and held rigidly by the rigid
polystyrene insulation between the first and second baffle
sections. Subse~uently installed sections are similarly
interconnected. The remaining half section of insulation
6.
from the first baffle section is then used in the last
baffle section to complete the assembly. After all the
necessary baffle lengths have been installed along the
wall or ceiling, the winch system is attached, wherein
each baffle section is attached to the main line 48 of the
cable or rope by attachm~nt lines 54. The counterweight
60 is then installed at the end of the main line to pro-
vide tension on the cable system. Turning of the winch
or pulley ~6 winds a section of the main line o~ the cable
or rope on the reel, thereby raising the counterweight and
pulling the attachment lines longitudinally, reducing the
length of the attachment line below eye bolt 52, thus rais-
ing the baffle toward the ceiling. When the winch 46 is
reversed, thereby letting out line along the main line
length, the counterweight pulls the main line toward the
opposite end of the baffle system from that of t~Se winch,
thereby moving the connection points of the attachment
and main lines closer to eye bolt 52, thus lowering the
baffle sections.
During the summer, the clq~ure board 30 is left
open, and~air is exhausted from the interior of the building
by a ~an or blower (not shown~ resulting in reduced air
pressure within the building compared to the outside, and
exterior air enters through screen 28 which keeps out in-
sects, birds, debris or the like, passes over the top of
wall portion 22 and enters the interior of the building
through opening 34. In a substantially horizontal position,
baffle 38 will direct the incoming air directly across the
ceiling from where it will gradually settle toward the floor,
or in a more open position, it will permit the incoming air
to settle more quickly toward the floor of the interior.
During the cold winter months, closure board 30 is raised,
thereby shutting off screen 28 and restricting the entrance
of air at that point. As the air is exhausted from the
interior of the building, the air in the space above the
ceiling 18 and below roof 12 will be of greater pressure
than the reduced pressure of the interior of the building
when the fan or blower is operating/ and hence will pass
above headerboard 20 through opening 36 and will then enter
the interior of the building through opening 34. Once again
the position of the baffle will direct or divert the air in
various selected directions. I~ the incoming air is directed
across the ceiling, the rising heat from within the building
will partially warm the air before it mixes with the interior
air. It should be noted that the natural tendency of heat
to rise also causes the air above ceiling 18 to be of sig-
nificantly higher temperature than the exterior air during
the winter months. Thus, by closing closure board 30, and
using the air above ceiling 18 as the air supply for the
building, warmer air is being used in replacing the air
withdrawn by the fan or blower. Thiso along with the in-
sulation ~n the baffle, minimizes condensation and a build
up of ~ost on and around the baffle. The interior air
will contact the lower surface of the baffle, but the in-
sulation in the baffle will prevent the incoming air from
cooling the lower surface. The top surface will be cool
but the lower surface will remain warm. It should also be
noted that if, in extremely cold weather, some frosting
does occur, since the baffle of the present invention does
not use hinges, there is no danger of the adjustabili~y
of the baffle being restricted due to the freezing of a
hinge. The flexibls strip 40 tends to remain flexible even
i~ it is covered with frost.
Flexible strip 40 can also be attached to the
ceiling 18 rather than to the walls. In such an installa-
tion, the baffle will then direct the flow of incoming air
down the interior of the wall rather than across the ceiling.
The baffle can also be used in situationSwhere the only
supply of fresh air is from the outside of the building.
The insulation of the baffle in such an installation will
significantly reduce the amount of condensation and frost
build up by keeping the baffle surface facing the interior
of the building from being excessively cooled by the in-
coming air. Howeverr especially in colder climates, the
overall design utilizing a closure board and air supply
from the air above the ceiling is preferred in that it
provides warmer incoming air, which will help prevent con-
densation and will help in maintaining higher interior
temperatures.
The polystyrene and plastic sheet construction
of the baffle makes it inherently light, therefore making
installation easy and efficient~ Due to this light weight,
the baf~le can be made in lonc3er sections, thereby elimin-
ating the number of joints which would otherwise be re-
quired when the baffle is installed in a long building,
and will reduce the chance of air leaks in the baffle.
The insulated portion of the baffle can be used with con-
ventional type mechanical hinges in place o~ the fle~ible
strip; however, the flexible strip is prefQrred due to
both ease o~ installation and ease in servicing in the
event some frosting occurs. Other insulating materials
can be used; however, the polystyrene type is also pre-
ferred as it provides ma~imum insulation value with mini-
mal thickness rec~uirements and retains its shape and does
not pack or settle within the hollow interior of the baffle.
Although one embodiment and several modifications
have been described in detail herein, various other changes
and modifications may be made without departing from the
scope of the present invention.
