Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02827693 2013-09-17
s
,
WATER RESISTANT DOOR THRESHOLD AND SYSTEM
Field of the Invention
The invention relates to entryway systems, and more particularly, to a self-
draining
water resistant door threshold and system.
Background of the Invention
Inswing doors, by virtue of their design, are often more prone to drafts and
leakage than
their outswing counterparts. An outswing door can utilize a jamb and
compression
gaskets in order to seal out water and air. In contrast, inswing doors are
reliant on
obtaining additional protection from outside elements through the threshold. A
basic
threshold (see for example Figure 1) is often composed of wood or aluminum and
typically has at least one upward projecting portion that contacts the bottom
portion of a
door in order to provide a physical barrier. Often the door and/or the
threshold have
additional features to enhance the strength of the physical barrier, such as a
sweep or a
rubber seal. The basic functions of the threshold are to provide an additional
barrier to
minimize or eliminate the passage of water or air into the building.
In certain geographical regions, such as coastal areas, additional protection
at
entryways is warranted and necessary as high rainfall levels, driving rains,
tropical
storms etc. test the limits of these barriers. Under the conditions associated
with
thunderstorms, hurricanes etc., high winds bombard the door with rain at
excessive
forces that often result in penetration of water, with the point of entry
typically being the
interface between the door and the threshold. An elevated positive pressure
created by
such weather conditions on the exterior of the door also contributes to
forcing water
and/or air through the door-threshold interface. In the instance of self-
draining
thresholds, strong weather conditions can force water and/or air to breach the
entryway
through the threshold itself.
There have been numerous attempts in the prior art to create a threshold that
has
improved resistance to water and/or air penetration, including the following.
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United States Patent No. 7,669,369 discloses a door threshold water return
system
comprising a lower sill; an upper sill; a rear wall; and a front wall forming
a chamber,
wherein at least one baffle is provided projecting into the chamber from the
rear wall, a
first gap is provided in proximity to the rear wall and between the upper sill
and the rear
wall, and a second gap is provided in proximity to the lower sill and between
the lower
sill and the front wall, whereby water introduced into the system through the
first gap
exits the system through the second gap.
United States Patent No. 8,448,384 discloses a doorway with a sill attachment
that
includes a sill, which is a substantially hollow contain-and-drain type sill
with a nosing
provided with drainage openings. A substantially hollow sill attachment is
mounted to
and extends along the nosing and the attachment projects downwardly to a
position
below the openings in the nosing of the sill. The drainage openings
communicate with
the interior of the extension. Weep holes that communicate with the
environment are
located in the sill attachment at a position below the openings in the nosing
of the sill.
United States Patent No. 5,067,279 discloses a self-draining door threshold,
which
includes a wedge-shaped silicone check valve in communication with a water
reservoir
on the interior side. The check valve is normally closed but will open in
response to
water pressure which overcomes the resilience of the silicone material and the
air
pressure on the top wall of the wedge-shaped passageway. The check valve
functions
as a seal against incoming air but will open to allow escape of water as
needed. The
silicone material seals around foreign material in the valve making it air
tight.
United States Patent No. 8,033,056 discloses a doorway with an anti-bubbling
sill drain,
which includes an outside nosing provided with weep holes and weep doors and a
threshold portion that directly underlies a closed door mounted in the frame.
A drain
insert is mounted within the threshold portion of the sill for allowing water
collected on
the threshold portion to drain into the sill and for allowing air within the
sill to vent.
United States Patent No. 7,600,346 discloses a threshold assembly which
includes a sill
having a first wall extending upwardly from the proximate end of an entry
portion and a
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õ
second wall extends upwardly from the sill and along the first wall to define
a channel
extending longitudinally between jamb pedestals. The first wall defines an
opening
which establishes fluid communication from the channel to the entry portion of
the sill
between the jamb pedestals for directing water from the channel away from the
threshold assembly along the entry portion.
United States Patent No. 5,179,804 discloses a self-draining door sill
assembly for use
in the bottom of an exterior door frame of a house. The assembly includes a
threshold
and base that define an elongated water chamber therebetween and the threshold
defines an upwardly opening storm drain channel formed in and along an upper,
interior
side surface portion thereof which terminates in a pair of slots located in
opposite ends
of the threshold, which slots also communicate with the underlying water
chamber. A
pair of spaced apart weep channels are formed in the base and extend from a
floor of
the water chamber along the exterior side of the base, such that rain water
which blows
or seeps past the primary seal gathers in the drain channel, flows through the
slots onto
the floor of the water chamber, migrates along the floor to the weep channels,
and then
flows through the weep channels out of the assembly.
United States Patent No. 5,136,814 discloses a draining threshold and door
sill
assembly, having an elongated frame member forming an upwardly open channel
and a
sill that slopes away from the channel. A threshold cap is removably captured
within the
channel and protrudes slightly thereabove. An end cap is securely fastened to
an end of
the assembly and is formed with a drain trough that extends transversely
beneath the
end of the assembly. Rain water that seeps under the threshold cap and into
the
channel flows to the end of the channel and into the drain trough of the end
cap, which
directs the water beyond the outside edge of and away from the assembly.
In light of the door threshold systems described above, a need still exists
for an easily
modifiable door threshold with improved air and water resistance that
typically exceeds
building code performance requirements.
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Summary of the Invention
According to an aspect of the present invention, there is provided a self-
draining
threshold assembly comprising a threshold cover for mounting on a threshold
support; a
chambered covering attached to the upper portion of the threshold cover, the
chambered covering comprising an interior vertical wall, an exterior vertical
wall, a lower
member, an upper member and end caps, that define therein a reservoir chamber,
and
the chambered covering having an opening in the upper member to receive
liquid; a
weep hole in the exterior vertical wall of the chambered covering that
provides for liquid
communication between the reservoir chamber and the sill cover, the weep hole
being
elevated a predetermined distance above the sill cover.
The threshold assembly may also comprise a deflector that attaches to the
chambered
covering, thereby physically shielding the weep hole. Deflectors may vary in
shape and
size in order to provide a range of leakage protection to the assembly.
Preferably the
upper surface of the chambered covering is elevated a predetermined distance
above
the upper surface of the deflector.
It is preferred that the sill cover slope downward and away from the door-
threshold
interface. At the end of the threshold support, the sill cover can extend
downward to
produce a blunted nose to the assembly, or alternatively, threshold extensions
of
various shapes and sizes can be attached to the sill cover. The ability to
modify the
assembly, such as through interchanging deflectors and/or threshold extensions
provides a versatile product.
According to a further aspect of the present invention, there is provided a
water
resistant threshold system comprising a self-draining threshold assembly
according to
the present invention; at least one sweep for mounting on the lower portion of
a door; at
least one primary seal for mounting on the lower portion of the door to come
into
frictional contact with the upper surface of the chambered covering; and at
least a
primary weather seal to facilitate a seal between the door and jamb interface.
According to another aspect of the present invention, there is provided a
doorway
comprising two opposing side jambs spaced apart by an upper head jamb; a door
panel
swingably mounted within the side jambs and head jamb; and a self-draining
threshold
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,
assembly according to the present invention mounted between the lower portion
of the
side jambs.
Brief Description of the Drawings
The present invention will now be described in more detail having regard to
the
drawings in which:
Figure 1 is a cross-sectional view of a known inswing door threshold;
Figure 2 is a cross-sectional view of a water resistant door threshold system
according
to an embodiment of the present invention;
Figure 3 is a cross-sectional view of the threshold assembly according to an
embodiment of the present invention;
Figures 4A ¨ 4G are cross-sectional views of threshold covers and threshold
extensions according to multiple embodiments of the present invention; and
Figure 5 is a cross section view of a mounted door from the water resistant
door
threshold system according to an embodiment of the present invention.
Detailed Description of the Invention
A better understanding of the present invention and its objects and advantages
will
become apparent to those skilled in this art form the following detailed
description,
wherein there is described only the preferred embodiment of the invention,
simply by
way of illustration of the best mode contemplated for carrying out the
invention. As will
be realized, the invention is capable of modifications in various obvious
respects, all
without departing from the scope and spirit of the invention. Accordingly, the
description
should be regarded as illustrative in nature and not as restrictive.
The Figures illustrates a water resistant door threshold system 1 according to
an
embodiment of the present invention. As shown in Figures 2 and 3, the water
resistant
door threshold system 1 comprises a door 2, a threshold assembly 3, as well as
additional sealing means, such as interior and exterior sweeps 5 and/or
primary seal 7.
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According to one embodiment of the invention as shown in Figure 3, the
threshold
assembly 3 comprises a threshold cover 9 that is attached to and covers a
threshold
support 11. It is preferable that the threshold cover 9 slopes downwardly away
from the
door-threshold interface 13 in order to direct water away from the interior of
the building
A. The threshold cover 9 is preferably aluminum or some other material that is
durable
and resistant to the penetration of water. The length and width of the
threshold cover 9
may vary as necessary in order to accommodate different threshold supports 11
that
may be routinely used in the construction of entranceways.
Extending upward from the interior portion of the threshold support 11 is a
chambered
lo covering 15 that extends the length of the threshold support 11. The
chambered
covering 15 comprises interior 17 and exterior 19 vertical walls that combine
with an
upper member 21, a lower member 23 and end caps (not shown) to define a
reservoir
chamber 25 that preferably extends the length of the threshold support 11. The
chambered covering 15 may be integral with the threshold cover 9, or
alternatively, the
chambered covering 15 may be a separate piece that attaches to the threshold
cover 9
through e.g. a snap fit connection, male-female connectors etc. The use of
separate
pieces increases the flexibility of the assembly 3 by allowing for
interchangeability of
threshold covers 9 with different chambered coverings 15.
The interior vertical wall 17 is preferably secured to the threshold support
11 at its lower
end, such as through a first foot 27 or other connecting member extending
inwardly
from the interior vertical wall 17, which aids in securing the chambered
covering 15 to
the threshold support 11. A lip 29 extends inwardly at the top portion of the
interior
vertical wall 17 to form part of the upper member 21. The remainder of the
upper
member 211s formed by a substantially horizontal extension 33 from the upper
portion
of exterior vertical wall 19. The extension 33 and the lip 29 form an opening
31 in the
upper member 21 that serves to capture water before it penetrates the
threshold
assembly 3.
According to one embodiment as can be seen in Figure 3, inside the chamber at
least
one baffle 35 extends from the extension 33 toward the interior vertical wall
17.
Although in another embodiment, the baffle 35 may extend from the interior
vertical wall
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17 or the lip 29 toward the exterior vertical wall 19. Any water that
penetrates the
sweep 5 and the primary seal 7 will be substantially captured by the opening
31 and
directed by the baffle 35 into the reservoir chamber 25. The width of the
baffle 35 may
vary, but is preferably equivalent or greater to the width of the opening 31.
Preferably, the lower member 23 of the chambered covering 15 is elevated a
predetermined distance above the threshold cover/threshold support 9,11. In
one
embodiment, there is a void space 37 between the lower member 23 and the
threshold
cover/threshold support 9,11, however, this space 37 may be filled with solid
material or
at least one vertical support in order to structurally strengthen the
chambered covering
1.0 15. As can be seen in Figure 3, there is a void space 37 under the
lower member, but
in this embodiment, there is an additional support structure 39 that
communicates
between the lower member 23 and the interior vertical wall 17. This support
structure
39 also facilitates securing the chambered covering 15 to the threshold
support 11,
particularly when the threshold support 11 is in a snug fit between the first
foot 27 and
the support structure 39.
Within the exterior vertical wall 19, there is a weep hole 41 that provides
for controlled
liquid communication between the reservoir chamber 25 and the external
environment.
The weep hole 41 may be continuous and extend along the length of the
chambered
covering, i.e. from side jamb to side jamb along the width of the doorway, or
alternatively, there may be a plurality of weep holes 41 of any particular
size that are
located at certain distances along the exterior vertical wall 19 of the
chambered
covering 15. The elevation of the lower member 23 of the chambered covering 15
creates a weep hole drop y between the weep hole 41 and the threshold cover 9.
Water that breaches the sealing means (e.g. sweep 5 and/or primary seal 7)
between
the bottom of the door 2 and the chambered covering 15 will flow through the
opening
31 and become trapped in the reservoir chamber 25. The water is then able to
vent
through the weep hole 41, down the weep hole drop y onto the threshold cover 9
where
it runs off the threshold assembly 3. The weep hole drop y is substantially
vertical,
however, it is possible that the weep hole drop y is sloped downward to the
threshold
cover 9.
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õ .
In one embodiment, the weep hole 41 is gated, and is biased to the closed
position. For
example, the gated weep hole 41 could be a type of check valve, such as a ball
check
valve, a diaphragm check valve, a swing check valve, a stop-check valve, a
lift-check
valve, an in-line check valve or a duckbill valve. Any other type of covering
for the rain
.. gate is contemplated, provided that under a certain pressure it yieldably
releases to
allow flow in one direction, while minimizes or eliminates flow in the
opposing direction.
In this embodiment, a predetermined amount of water is required in the
reservoir
chamber before the gated weep hole 41 reverts to an open position, at which
time the
collected water can vent through the weep hole 41, down the weep hole drop y
onto the
.. threshold cover 15 where it runs off the threshold assembly 3. The gated
weep hole 41
provides additional protection against water leakage, as under certain weather
conditions, such as strong winds and driving rain, water and/or air may
penetrate an
ungated weep hole 41. Once in the reservoir chamber 25, the water and/or air
could
pass up through the opening 31 and into the interior of the building A. The
nature of the
gated weep hole 41 would minimize the entry of water and/or air from the
external
environment into the reservoir chamber 25, even under conditions of strong
wind,
driving rain and elevated pressure.
The weep hole drop y provides further resistance to the backflow of water into
the
reservoir chamber 25. During rainfall, rainwater that hits the sloped
threshold cover 9
.. will typically drain away from the chambered covering 15. However, large
precipitation
levels can cause the accumulation of water on the threshold cover 9,
potentially placing
additional pressure on the weep hole 41. This added pressure increases the
probability
of a breach of the weep hole 41. The existence of the weep hole drop y
requires that
the water will need to rise substantially vertically at least the
predetermined distance y
before it is able to exert additional pressure on the weep hole 41. Reducing
additional
pressure on the gated weep hole 41 by deterring the buildup of external water
may also
prolong the functionality of the valve. The height of the weep hole drop y is
not limiting,
but it is preferred that it be at least 3/16 of an inch in order to provide a
desirable
deterrent to the backflow of water. Smaller or larger heights of the weep hole
drop y will
likely provide less or more of a deterrent to the backflow of water,
respectively.
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õ
In one embodiment of the present invention, the threshold assembly 3 includes
at least
one deflector 43, that enhances resistance to air and water leakage when
installed on
the assembly 3. Ideally the assembly 3 comprises a plurality of
interchangeable
deflectors 43 of differing shapes and sizes that are installed based upon the
water and
resistance needs. The deflector 43 comprises a first end 45, a second end 47
and a
shield portion 49, that acts as a physical shield which preferably provides
some
protection for a portion of the threshold cover 9, the exterior vertical wall
19 and/or the
weep hole 41, such as by physically shielding these components from direct
assault by
wind and rain. This will further minimize or reduce any potential backflow of
water
and/or air through the weep hole 41, and may increase the longevity and
functionality of
the gated weep hole 41. The deflectors 43 primarily extend outward and
downward
from the chambered covering 15. They may be integral with the chambered
covering
15, but preferably, the deflector 43 is removably attached thereto, such as by
a snap fit
connection, thereby allowing for a plurality of deflectors 43 to be
interchanged in the
assembly 3 as required. Depending upon the size and/or shape of the deflector
43,
varying degrees of additional protection can be attained.
As is illustrated in one embodiment shown in Figures 2 and 3, a connector 51
extends
outwardly from the exterior vertical wall 19 to detachably receive the
deflector 43.
According to one aspect of the present invention, multiple deflectors 43 of
varying sizes
and shapes can be designed have a mating connector 53 at a first end 45
thereof for
removeable attachment to the connector 51. For example, Figure 3 illustrates a
small
deflector 43 that is arcuate in shape, that when removeably attached to the
connector
45, the shield portion 49 thereof curves outward and downward toward the
threshold
cover 9. Alternatively, a large deflector 43 has a substantially linear shield
portion 49,
that when removeably attached to the connector 51, extends outward from the
exterior
vertical wall 19 and gradually slopes downward ending near the nose of the
threshold
cover 9.
The second end 47 of the deflector 43 may contact the threshold cover 9, but
may also
hover just above. Contacting the threshold cover 9 may comprise resting the
second
end 47 on the threshold cover 9, in which case driving rain could still be
forced
therebetween. Or alternatively, the second end 47 of the deflector 43 can be
attached
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to the threshold cover 9, removeably or otherwise. For example, the second end
47 of
the deflector 43 may attach directly to the threshold cover 9, such as through
a snap fit
connection, or as illustrated with the large deflector, a deflector leg 55 may
extend
downwardly from the deflector 43 and contact the threshold cover 9. The
deflector leg
55 may attach directly to the threshold cover 9, such as through a snap fit
connection,
or the deflector leg 55 may have a deflector foot 57 or other mating connector
at its
connecting end that, e.g. engages with a channel 59. Anchoring the deflector
leg 55
further minimizes penetration of water through the threshold assembly 3, as
wind and
rain will not have direct access to the weep hole 41, thereby limiting any
potential
backflow through the weep hole 41.
By virtue of the nature of the assembly, the deflector will receive
compression forces
through foot traffic, and therefore, additional legs may be provided between
the first and
second ends of the deflector 43, in order to provide further structural
support.
According to one embodiment, the deflector leg 55 will have at least one
deflector leg
weep hole (not shown), particularly when the deflector leg is removeably
attached to the
threshold cover. The deflector leg weephole will allow water draining from the
reservoir
chamber 25 through the weep hole 41 to flow down and off the threshold cover
9.
Preferably the deflector 43 does not extend outwardly such that the shield
portion 49 is
initially on plane with the top surface of the upper member 21 of the
chambered
covering 15. As shown in Figure 3, it is preferred that that deflector 43 (or
the connector
51 that removeably attaches the deflector 43) extends outwardly from the
exterior
vertical wall 19, creating a deflector drop x from the top surface of the
upper member 21
of the chambered covering 15 to the deflector/connector 43,51. If the
deflector 43 was
initially on plane with the upper surface of the chambered covering 15, wind
driven rain
could be pushed directly up the deflector 43, past the sweep 5 and the primary
seal 7.
Such a volume of water could overwhelm the drainage system present in the
chambered covering 15. The existence of the deflector drop x ensures that
water driven
up the deflector 43 by wind is not directly pushed into the door-threshold
interface 13,
but rather the water will abut against the front face of the exterior vertical
wall 19. The
water level will need to rise substantially vertically at least the
predetermined distance x
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before it is able to exert additional pressure on and/or breach the sweep 5
and primary
seal 7. The deflector drop x is substantially vertical, however, it is
possible that the
deflector drop x is sloped downward. The height of the deflector drop x is not
limiting,
but it is preferred that it be at least 3/16 of an inch in order to provide a
desirable
deterrent to the run up of water through the door-threshold interface 13.
Smaller or
larger heights of the deflector drop x will likely provide less or more of a
deterrent,
respectively.
In one embodiment, the threshold cover 9 extends downward to form a nose cover
61
on the front portion of the threshold support 11. Preferably, the threshold
cover 9 at
least partially envelops the front nose of the threshold support 11 in order
to secure the
threshold cover 9 thereon. This may provide a flat blunted finish to the
threshold
assembly 3, however, in another embodiment, the threshold cover 9 may extend
outward, gradually or otherwise, to provide a tapered finish to the threshold
cover until it
meets the ground.
Alternatively, as shown in Figure 3, the front face of the nose of the
threshold cover 9
may have attachment means 63 that allow for the attachment of threshold
extensions
65 of differing sizes and lengths (see Figures 4A ¨ 4G). These Figures
illustrate the
attachment of threshold extensions 65 to the front of the threshold cover 9 by
way of
snap fit means, although other means of attaching a threshold extension to the
threshold cover are also contemplated. For example, as shown in Figures 4A to
4C, at
least one connector 67, such as a male connector, extends outwardly from the
front
face of the nose of the threshold cover 9. Complementary extension connectors
69 in
the threshold extension 65 receive or snap into the connector 67, providing
for a snug fit
of the threshold extension to the front of the threshold cover. The ability to
interchangeably attach threshold extensions 65 of differing sizes to the
threshold cover
9 will allow for the manufacture of a versatile single design of the threshold
assembly 3
that can be tailored to fit a specific environment or need. These Figures also
illustrate
variations in the size and shape of the threshold cover 9 that are
contemplated. The
threshold cover 9 may have at least one additional sill cover leg 70 in order
to provide
further support and stability. Screw bosses 71 can also be added to the
underside of
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the threshold cover 9, which will facilitate the attachment of the threshold
cover 9 to the
threshold support 11.
The threshold assembly 3 of the present invention may also be combined with
additional features to provide a system. For example, the threshold assembly
may be
combined into a kit that further includes at least one of: at least one sweep
5 for
mounting on the bottom portion of exterior and/or interior of the door; at
least one
primary seal 7 that attaches to the bottom of the door and physically contacts
the
threshold assembly to form a seal; primary and/or secondary weather stripping
75,77
that can be added either to the door or to the side jamb 79, head jamb or
hinge 73 as
needed to further enhance the leakage protection of the doorway. The
components are
not particularly limiting, and would be well known to one of skill in the art.
The threshold assembly 3 can also be incorporated into e.g. a prefabricated
door
system. In such an embodiment, a typical doorway has been constructed
comprising
two opposing side jambs, a head jamb and the threshold support 11. The
threshold
assembly 3 is already mounted onto the threshold support 11. A door may or may
not
already be hingedly mounted to the doorway.
Examples
Structural and functional testing of windows and doors is performed in order
to achieve
a rating that signifies how these products are able to perform under various
weather
conditions, such as during tropical storms and hurricanes. Many building
codes, such
as those present in coastal areas, now require such testing, and often require
products
to reach certain standards and requirements prior to approval for use in
building
construction.
An inswing entry door utilizing a threshold assembly 3 according to the
present
invention was produced and was subjected to certain standardized tests in
order to
observe and assess performance.
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Air Leakage Resistance
Two mock-ups of the threshold assembly according to the present invention were
subject to testing in accordance with ASTM E 283. The assembly was subjected
to an
air pressure of 75 pascals in both a positive and negative direction
perpendicular to the
plane of the unit. The amount of air permeating the test unit (air leakage) is
recorded in
the positive and negative directions.
As a result of the above noted test pressures, the test specimen exhibited air
leakage
rates as shown in the following tables, which would place the ability of the
threshold
assembly to prevent or minimize air leakage well above minimum requirements.
TEST UNIT 1
Air Leakage Rate (L/s/m2)
First Test 0.046
Second Test 0.057
Third Test 0.044
Average 0.049
TEST UNIT 2
Air Leakage Rate (L/s/m2)
First Test 0.031
Second Test 0.031
Average 0.031
Water Leakage Resistance
Two mock-ups of the threshold assembly according to the present invention were
subject to testing in accordance with ASTM E 547. The assembly was subject to
a four-
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=
cycle water test. Each cycle consists of five minutes with a positive pressure
applied to
the exterior of the door followed by one minute where the pressure has been
released,
during which a continuous water spray (5 US gal/ft2/hr) is applied to the
exterior. The
interior of the door is monitored for any water leakage. Each successive test
is
performed at a specified pressure that ultimately dictates the design pressure
(DP)
designation for a unit. The highest test pressure that an assembly passes
relates to the
DP designation that is afforded to an assembly.
As a result of the above noted test pressures, the test specimens obtained DP
ratings
as shown in the following table, which would place the ability of the
threshold assembly
to prevent or minimize water leakage well above minimum requirements.
TEST UNIT 1
DP RATING
First Test DP 75 (540 Pa)
Second Test DP 100 (730 Pa)
TEST UNIT 2
DP RATING Notes
First Test DP 100 (730 Pa)
Second Test DP 95 (690 Pa) Faulty Sweep On Door
Third Test DP 100 (730 Pa)
Fourth Test DP 25 (180 Pa) No Deflector Used
Fifth Test DP 50 (360 Pa) Small Deflector Used
=
14
