U.S. patent application number 13/463952 was filed with the patent office on 2013-06-13 for barometric relief air zone damper.
The applicant listed for this patent is Ronald E. Jackson. Invention is credited to Ronald E. Jackson.
Application Number | 20130146272 13/463952 |
Document ID | / |
Family ID | 48570922 |
Filed Date | 2013-06-13 |
United States Patent
Application |
20130146272 |
Kind Code |
A1 |
Jackson; Ronald E. |
June 13, 2013 |
BAROMETRIC RELIEF AIR ZONE DAMPER
Abstract
A zone damper having a first portion and second portion
controlled by a actuator to move between an open and a closed
position in response to a zone thermostat, a second portion
responsive to the static pressure in a HVAC system to open and
bleed an amount of conditioned air past the damper when the static
pressure of the system increases above a selected level, and a
weight adjustment for modifying the torque exerted by the second
portion against the system static pressure to adjust the selected
level.
Inventors: |
Jackson; Ronald E.;
(Indianapolis, IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Jackson; Ronald E. |
Indianapolis |
IN |
US |
|
|
Family ID: |
48570922 |
Appl. No.: |
13/463952 |
Filed: |
May 4, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61569845 |
Dec 13, 2011 |
|
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|
Current U.S.
Class: |
165/217 ;
236/49.3; 236/49.5 |
Current CPC
Class: |
F24F 11/30 20180101;
F24F 13/10 20130101; F24F 11/74 20180101; F24F 2110/00 20180101;
F24F 11/745 20180101; F24F 13/14 20130101 |
Class at
Publication: |
165/217 ;
236/49.3; 236/49.5 |
International
Class: |
F24F 13/10 20060101
F24F013/10; F24F 3/00 20060101 F24F003/00 |
Claims
1. A zone damper responsive to a zone thermostat, the damper
comprising a shell including a mechanical portion responsive to a
static pressure differential in a HVAC system to open and bleed an
amount of conditioned air past the damper when the static pressure
of the system increases above a selected level.
2. The zone damper of claim 1, further comprising a biasing member
coupled to the mechanical portion for biasing the mechanical
portion toward a closed position.
3. The zone damper of claim 2, wherein the biasing member is either
a spring or a weight.
4. The zone damper of claim 1, further comprising another
mechanical portion movable only in response to the zone thermostat,
and a lock adapted to couple the two mechanical portions to limit
the relative movements of the two mechanical portions with respect
to each other.
5. A zone damper comprising a shell containing a first portion and
second portion controlled by a actuator to move between an open and
a closed position in response to a zone thermostat, the second
portion being movable relative to the first portion and responsive
to the static pressure in a HVAC system to open and bleed an amount
of conditioned air past the damper when the static pressure of the
system increases above a selected level.
6. The zone damper of claim 5, further comprising a biasing member
coupled to the second portion to bias the second portion into
alignment with the first portion.
7. The zone damper of claim 6, wherein the biasing member comprises
at least one weight situated on the second portion so that gravity
acting on the at least one weight biases the second portion into
alignment with the first portion.
8. The zone damper of claim 6, wherein the biasing member comprises
at least one spring coupled between the first and second
portions.
9. The zone damper of claim 5, further comprising a lock adapted to
couple the first and second portions together to limit the relative
movement of the second portion with respect to the first
portion.
10. A zone damper comprising a shell, a first portion and second
portion mounted within the shell and controlled by an actuator to
move between an open and a closed position in response to a zone
thermostat, the second portion being movable relative to the first
portion and responsive to the static pressure differential in a
HVAC system to bleed an amount of conditioned air past the zone
damper when the static pressure differential of the system
increases, and a basing element coupled to the second portion to
resist movement of the second portion until the static pressure
differential reaches a selected level.
11. The zone damper of claim 10, further comprising an adjustment
feature for adjusting the bias exerted by the biasing element
against the system static pressure differential to adjust said
selected level.
12. The zone damper of claim 11, wherein the biasing element
comprises a weight coupled to the second portion.
13. The zone damper of claim 12, wherein the adjustment feature
comprises an opening in the shell permitting access to the weight
for changing the size and/or location of the weight.
14. The zone damper of claim 10, wherein the biasing element
comprises a spring coupled to the first and second portions.
15. The zone damper of claim 10, further comprising further
comprising a lock adapted to couple the first and second portions
together to limit the relative movement of the second portion with
respect to the first portion.
16. The zone damper of claim 15, wherein the lock is movable
between an unlocked position allowing movement of the second
portion relative to the first portion, and a locked position
preventing any relative movement between the first and second
portions.
17. The zone damper of claim 10, further comprising a shaft coupled
to the actuator and passing through the shell, the shaft being
fixed to the damper first portion for concurrent movement
therewith.
18. The zone damper of claim 17, at least one hinge coupling the
second portion to the shaft and first portion to permit movement of
the second portion relative to the shaft and first portion.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is related to and claims all benefit of
U.S. Provisional Application Ser. No. 61/569,845 filed Dec. 13,
2011.
BACKGROUND
[0002] This invention relates to heating, ventilating and air
conditioning ("HVAC") systems that include at least two zones
controlled by sensors, generally thermostats, located within the at
least two zones that control corresponding dampers in ducts leading
from usually a single HVAC source to the at least two zones.
[0003] In a conventional HAVC zoning system, conditioned air can be
supplied to a plurality of zones, each zone being controlled by its
own thermostat. Zoning systems for such an HVAC system typically
includes zone dampers disposed in the ductwork for controlling the
air flow of the conditioned air to the zones in response to the
thermostat. These zoning systems control the flow of conditioned
air to the plurality of zones independently so as to allow for
independent control of the zone environments. As a result, at any
given time a number of zone dampers may be open or closed. As the
temperature in each zone is satisfied, its zone damper will close
causing the static pressure in the duct system to rise. This rise
in static duct pressure can result in an increase in noise and
drafts due, in part, to an increase in air flow velocity though the
ducts in zones still calling for conditioned air.
[0004] Conventionally, a bypass damper system is used to relieve
excess static duct pressure. For example, a bypass damper can be
connected between the supply and return air duct. If the bypass
damper system determines that the air flow to a supply air duct is
causing excess static duct pressure, then the bypass damper will be
modulated open to recycle the conditioned air from the supply air
duct to the return air duct. This implementation has the
disadvantage of being energy inefficient, and hence an expensive
way to solve the problem. Bypass dampers can also be expensive to
install and difficult to setup. Elimination of the aforementioned
bypass damper system could reduce the amount of HVAC system
equipment, which, in turn, would reduce installation and
maintenance costs.
[0005] What is needed is alternative apparatus that can effectively
and efficiently control excess static duct pressure without
resorting to the use of a bypass damper.
SUMMARY
[0006] The alternative apparatus can take the form of each zone
damper being replaced with a zone damper that, in addition to being
controlled by the corresponding zone thermostat, also includes a
mechanical portion responsive to the barometric pressure
differential in the system to open and bleed a small amount of
conditioned air into each zone when the static pressure of the
system increases above a selected level.
[0007] In a preferred embodiment the zone damper can include two
portions that are hinged to each other to permit independent
movement of the two portions relative to each other. A first of the
portions can be connected to a damper actuator controlled by a
corresponding zone thermostat to open and close in response to the
need for conditioned air within the zone. A second of the portions
can also be moved by the damper actuator from the closed position
to an open position to ensure maximum air flow through the duct in
response to the need for conditioned air within the zone. As the
first portion moves from the open position to the closed position,
the second portion can also move toward the closed position, but
may not entirely close if the static pressure differential in the
system is too high.
[0008] In a preferred embodiment the second portion of the zone
damper can include a counter balance weight, which may be
adjustable, to set the desired static pressure differential value
that will be allowed. If the system static pressure differential
rises above the set desired pressure differential value, the second
portion responds by opening sufficiently to reduce the system
static pressure differential to the desired value. The counter
balance weight and adjustment mechanisms can be of a variety of
constructions. A removable access panel can be provided in the zone
ducting adjacent to the zone damper to permit access to and
adjustment of the counter balance weight to the desired level.
Additionally, a lock or stop can be provided to fix the position of
the second portion relative to the first portion or to set the
maximum deflection of the second portion relative to the first
portion in certain situations.
[0009] A feature of the disclosed zone dampers is the inclusion of
barometrically responsive portions that effectively eliminate the
need for any bypass damper system and hence reduce the size of
damper inventory. An advantage of the disclosed zone dampers is a
reduction in drafts and air noise, and a reduction in coil freeze
up, with a resulting increase in system energy efficiency.
[0010] Other features and advantages of the present barometric zone
damper and the corresponding advantages of those features will
become apparent from the following discussion of preferred
embodiments, which is illustrated in the accompanying drawings. The
components in the figures are not necessarily to scale, emphasis
instead being placed upon illustrating the principles of operation.
Moreover, in the figures to the extent possible, like referenced
numerals designate corresponding parts throughout the different
views.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a perspective view of a barometrically responsive
zone damper positioned within a shell.
[0012] FIG. 2 is a schematic side elevation view of a
barometrically responsive zone damper positioned within a
shell.
[0013] FIG. 3 is a schematic front elevation view of a
barometrically responsive zone damper positioned within a
shell.
[0014] FIG. 4 is a schematic front elevation view of another
barometrically responsive zone damper positioned within a
shell.
[0015] FIG. 5 is a schematic front elevation view of yet another
barometrically responsive zone damper positioned within a
shell.
[0016] FIG. 6 is a schematic front elevation view of still another
barometrically responsive zone damper positioned within a
shell.
[0017] FIG. 7 is a side elevation view of a lock down clip that can
be used on a barometrically responsive zone damper to control the
relative displacement of the first and second portions of the
damper with respect to each other.
[0018] FIG. 8 is a schematic sectional view of a barometrically
responsive zone damper moved to a partially open position by a
damper actuator.
[0019] FIG. 9 is a schematic sectional view of a barometrically
responsive zone damper in a closed position with a lower portion
being moved to a partially open position by virtue of a pressure
differential across the damper resulting in an air flow through the
duct.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0020] FIG. 1 shows a barometrically responsive zone damper 10
positioned within a segment of ducting 11, which forms a damper
shell 12. The damper 10 can include an upper portion 14 and a lower
portion 16. The upper portion 14 can be fixed to a shaft 18 mounted
in bushings fixed in the shell 12, the shaft 18 extending through
the shell 12. The position of the shaft 18 and upper portion 14 of
the zone damper 10 can be controlled by a damper actuator 22 that
can be located on the outside or inside of the shell 12. The damper
actuator 22 can be situated on either side of the shell 12 and
controlled by a zone thermostat, not shown. The lower portion 16 of
the zone damper 10 is connected to the upper portion 14 of the
damper by a hinge 24 to permit independent movement of the lower
portion 16 relative to the upper portion 14. In the absence of a
sufficient air pressure differential or air flow through the
ducting 11, the force of gravity will cause the lower portion 16 to
pivot to a position in alignment with the upper portion 14 as
shown. The force acting to close the lower portion 16 can be
increased by attaching a weight 26 of selected size to the lower
portion 16.
[0021] The amount of the force acting to close the lower portion 16
can be modified by modifying the size of the weight 26 or by
adjusting the position the weight 26 so as to increase or decrease
the torque applied to the lower portion 16 as shown in FIG. 1 and
FIG. 3. A removable access panel 25 can be provided in the shell 12
adjacent to the zone damper 10 to permit access to and adjustment
of the counter balance weight 26 to the desired level. FIG. 3 also
shows the upper portion 14 fixed to the shaft 18, which can be
mounted in bushings 20, which can be formed of nylon or similar
durable material, fixed in the shell 12, the shaft 18 extending
through the shell 12. Both portions 14 and 16 are shown to have a
gasket 15, 17 adjacent to the shell 12 to provide a suitable seal
to prevent unwanted leaking past the zone damper 10. A lock 34 can
also be provided to fix the position of the lower portion 16 in
relation to the upper portion 14. The lock 34 can take the form of
a butterfly blade lock 36. When barometric pressure differential
relief is desired, the butterfly blade lock 36 can be rotated from
the locked position shown in FIG. 1 to a horizontal un-locked
position as shown in FIG. 4.
[0022] A variations of the barometric zone damper is shown in FIG.
2, which is a schematic side elevation view of a barometrically
responsive zone damper 10 positioned within a shell 12. The damper
10 is shown to include an upper portion 14 and a lower portion 16.
The position of the upper portion 14 of the zone damper 10 can be
controlled by a damper actuator 22 that can be located on the
outside of the shell 12. The damper actuator 22 can be controlled
by a zone thermostat, not shown. The lower portion 16 of the zone
damper 10 is connected to the upper portion 14 in a manner to
permit independent movement of the lower portion 16 relative to the
upper portion 14. In the absence of a sufficient air pressure
differential on opposite sides of the zone damper 10, or any air
flow through the ducting 11, the force of gravity will cause the
lower portion 16 to pivot into alignment with the upper portion 14.
Gaskets 27 can be included in the shell 12 to seal against damper
portions 14 and 16 when the portions are in a closed position. One
or more weights 26 can be added to or subtracted from a screw 28
located adjacent to a lower margin 30 of the lower portion 16 to
increase or decrease the force acting to close the lower portion
16.
[0023] FIG. 4 shows a schematic front elevation view of another
barometrically responsive zone damper 10 positioned within a shell
12. The damper 10 is shown to include an upper portion 14 and a
lower portion 16. The position of the upper portion 14 of the zone
damper 10 can be controlled by a damper actuator 22 located on the
outside of the shell 12. The lower portion 16 is connected to the
upper portion 14 in a manner to permit independent movement of the
lower portion 16 relative to the upper portion 14. In the absence
of a sufficient air pressure differential on opposite sides of the
zone damper 10, or any air flow through the shell 12, the force of
gravity will cause the lower portion 16 to pivot into alignment
with the upper portion 14. A lock 34 can also be provided to fix
the position of the lower portion 16 in relation to the upper
portion 14. The lock 34 can take the form of a butterfly blade lock
36. If, in a particular installation, no barometric pressure
differential relief is deemed necessary, the butterfly blade lock
36 can be rotated from the un-locked position shown in FIG. 4 to a
vertical locked position, in which case the damper 10 would perform
as a conventional zone control damper.
[0024] FIG. 5 is a schematic front elevation view of yet another
barometrically responsive zone damper 10 positioned within a shell
12. The damper 10 is shown to include an upper portion 14 and a
lower portion 16. The position of the upper portion 14 of the zone
damper 10 can be controlled by a damper actuator 22 located on the
outside of the shell 12. It is to be noted that in this embodiment,
no counter balance weight is coupled to portion 16. Instead, the
portion 16 is connected to the portion 14 by spring biased hinges
23, each incorporating a helical torsion spring 54, the hinges
permitting independent movement of the portion 16 relative to the
portion 14 and the springs 54 providing a desired biasing force. In
the absence of a sufficient air pressure differential on opposite
sides of the zone damper 10, or any air flow through the shell 12,
the force provided by the spring biased hinges 23 will cause the
lower portion 16 to pivot into alignment with the upper portion 14.
The amount of force can be determined by specifying the strength of
the spring element 54 included in the spring biased hinges 23, or
by specifying the number of spring biased hinges coupling the upper
portion 14 to the lower portion 16. While the spring element 54
providing the biasing force has been illustrated as being
incorporated into a spring biased hinge 23, the spring can take
other forms including, for example, a leaf or bow spring, or a
volute spring, coupled to both the upper portion 14 and the lower
portion 16. The shaft 18 can be located at any angle relative to
HVAC system as a whole, since the position of portion 16 in
relation to portion 14 is not governed entirely by gravity, but
rather by the force supplied by the one or more springs. This
allows for the barometrically responsive zone damper 10 to be
located in a duct 12 that may be vertically oriented or at least
inclined so that the force opposing any pressure differential is
only partly dependent on gravity.
[0025] A lock 34 can also be provided to fix the position of the
lower portion 16 in relation to the upper portion 14. The lock 34
in FIG. 5 takes the form of a strap 38, which can include a series
of holes 40 or a slot permitting the strap to be adjusted from an
unlocked position as shown in FIG. 5 to a position where a lower
end 42 of the strap 38 overlaps at least a portion of lower portion
16 to maintain the upper portion 14 and lower portion 16 in
alignment with each other. When the strap 38 is in the locked
position, the damper 10 would perform as a conventional zone
control damper.
[0026] FIG. 6 is a schematic front elevation view of still another
barometrically responsive zone damper 10 positioned within a shell
12, which is shown to be rectangular. The shape of the perimeter of
the zone damper 10 can be formed in any shape necessary for a given
installation. Again, damper 10 is shown to include an upper portion
14 and a lower portion 16. The position of the upper portion 14 of
the zone damper 10 can be controlled by a damper actuator. FIG. 6
shows a damper actuator 22 that has a sufficiently low profile to
lie in the region of a damper frame 47 surrounding the shell 12,
and between the shell 12 and a damper mounting plate 49 supporting
the damper 10 in the related HVAC system. As in the other
embodiments, the lower portion 16 is connected to the upper portion
14 by hinges 24 to permit independent movement of the lower portion
16 relative to the upper portion 14. In the absence of a sufficient
air pressure differential on opposite sides of the zone damper 10,
or any air flow through the shell 12, the force of gravity will
cause the lower portion 16 to pivot into alignment with the upper
portion 14. A lock 34 can also be provided to fix the position of
the lower portion 16 in relation to the upper portion 14. The lock
34 in FIG. 5 takes the form of a strap 38, which includes a slot 44
permitting the strap to be adjusted from an unlocked position as
shown in FIG. 6 to a position where a lower end 42 of the strap 38
overlaps at least a portion of lower portion 16 to maintain the
upper portion 14 and lower portion 16 in alignment with each other.
When the strap 38 is in the locked position, the damper 10 would
perform as a conventional zone control damper.
[0027] The strap 38 can also take the form shown in FIG. 7 is a
side elevation view of a clip 46 that includes a first portion 48
that can be coupled to a surface of the upper damper portion 14.
The clip 46 can also include a second portion 50 that can be
inclined at an angle a with respect to portion 48. The clip first
portion 48 can be positioned on the upper damper portion 14 so that
the junction 52 of the portions 48 and 50 overlies the junction of
the upper damper portion 14 and the lower damper portion 16. The
angle .alpha. of the clip 46 sets a maximum deflection that the
second portion 16 of the damper 10 can achieve relative to the
first portion 14. While FIG. 7 shows the portions 48 and 50 of clip
46 to be inclined at an angle of about 110.degree. relative to each
other, the angle can range between about 90.degree. and
140.degree.. While FIG. 7 shows the length L.sub.1 of portion 48 to
be greater than the length L.sub.2 of portion 50, the portions 48
and 50 may be of equal length.
[0028] An appreciation of the operation of the barometrically
responsive zone dampers 10 can be gained from a consideration of
FIGS. 8 and 9 in which the damper 10 includes a first portion 14
and a second portion 16. The first portion 14 is fixed to shaft 18
so that any rotation of shaft 18 will cause a corresponding angular
displacement of the portion 14. The position of the shaft 18 and
first portion 14 of the zone damper 10 can be controlled by a
damper actuator 22 that can be, in turn, controlled by a zone
thermostat, not shown. The second portion 16 is connected by one or
more hinges to the first portion 14 to permit independent movement
of the second portion 16 relative to the first portion 14. A
biasing force supplied by one or more weights, springs, or other
biasing means, or a locking element can be suitably positioned, to
maintain the second portion 16 in alignment with the first portion
14 as shown in FIG. 8. As the shaft 18 rotates from a closed
position C, in which the damper 10 blocks air flow through the duct
12, to a partially open position O, in which air can flow through
the duct 12 past the damper 10, both portions 14 and 16 move with
the rotation of the shaft 18 in the manner of a conventional zone
control damper.
[0029] In the absence of a locking element, or with the locking
element situated in an un-locked position allowing relative
movement between second portion 16 and first portion 14, the
rotation of shaft 18 will still cause a corresponding angular
displacement of the portion 14. Portion 16, however, is free to
respond to a pressure differential across the damper 10, which if
sufficient to overcome the biasing force, will allow portion 16 to
open to a relief position R even though portion 14 remains in the
closed position C as shown in FIG. 9 to bleed a sufficient amount
of air through the duct 12 to keep the static pressure differential
from rising to an unacceptable level.
[0030] With each of the illustrated variations, if the system
static pressure differential rises above the set desired pressure
value, the lower or second portion 16 of the zone damper 10 can
respond by opening sufficiently to reduce the system static
pressure to a desired value. In a preferred system, the biasing
force supplied by the one or more springs, or by the weights 26,
can be such that the second or lower portion 16 of the damper 10
will begin to open independent of the first portion 14 at
approximately 0.3'' WC of static pressure. The use of any of the
illustrated variations of barometric zone dampers effectively
eliminates the need for any bypass damper system.
[0031] While these features have been disclosed in connection with
the illustrated preferred embodiments, other embodiments of the
invention will be apparent to those skilled in the art that come
within the spirit of the invention as defined in the following
claims.
* * * * *