U.S. patent application number 17/173185 was filed with the patent office on 2021-06-03 for push-through conditioned air vestibule and controller.
This patent application is currently assigned to HCR INC.. The applicant listed for this patent is HCR INC.. Invention is credited to Gary Michael LANDERS, Daniel J. RHYNER.
Application Number | 20210164720 17/173185 |
Document ID | / |
Family ID | 1000005389729 |
Filed Date | 2021-06-03 |
United States Patent
Application |
20210164720 |
Kind Code |
A1 |
RHYNER; Daniel J. ; et
al. |
June 3, 2021 |
PUSH-THROUGH CONDITIONED AIR VESTIBULE AND CONTROLLER
Abstract
A push through conditioned air vestibule unit includes an air
vestibule having a top side, a first lateral side, and a second
lateral side forming a passage through the unit. Movable barrier
members are attached to the unit to reduce external air flow
through the passage. Return air ducts are configured to circulate
air to an air moving device and a temperature conditioning device.
Thermal and humidity sensors measure temperature and humidity of
the passage and an external room, and a system controller controls
the temperature of air moved into the passage using the temperature
conditioning device if the partial pressure of moisture vapor
internal to the passage is not greater than or equal to the partial
pressure of moisture vapor external to the passage.
Inventors: |
RHYNER; Daniel J.;
(Lewistown, MT) ; LANDERS; Gary Michael;
(Lewistown, MT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HCR INC. |
Lewistown |
MT |
US |
|
|
Assignee: |
HCR INC.
Lewistown
MT
|
Family ID: |
1000005389729 |
Appl. No.: |
17/173185 |
Filed: |
February 10, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14885294 |
Oct 16, 2015 |
10921049 |
|
|
17173185 |
|
|
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|
62067346 |
Oct 22, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F25D 23/023 20130101;
F24F 9/00 20130101 |
International
Class: |
F25D 23/02 20060101
F25D023/02; F24F 9/00 20060101 F24F009/00 |
Claims
1. An air vestibule unit configured to be positioned and provide
access between a first room and a second room, the first room being
warmer than the second room, the unit comprising: an air vestibule
forming a passage through the unit; a plurality of movable barrier
members arranged vertically to reduce external air flow through the
passage; an air moving device configured to move air into the
passage; a temperature conditioning device configured to adjust the
temperature of air moved into the passage by the air moving device;
an external thermal sensor positioned outside of the passage and
configured to measure a temperature in the first room; an internal
thermal sensor configured to measure a temperature within the
passage; an external humidity sensor positioned outside of the
passage and configured to measure humidity in the first room; an
internal humidity sensor configured to measure humidity within the
passage; a system controller configured to determine a partial
pressure of moisture vapor internal to the passage using the
temperature and humidity measured only in the passage and a partial
pressure of moisture vapor of the first room using the temperature
and humidity measured only in the first room, and to increase the
temperature of air moved into the passage using the temperature
conditioning device if the partial pressure of moisture vapor
internal to the passage is not greater less than or equal to the
partial pressure of moisture vapor of the first room only.
2. The air vestibule unit of claim 1, wherein the movable barrier
members comprise flexible strips hanging from a top side of the air
vestibule.
3. The air vestibule unit of claim 1, wherein the movable barrier
members are impact-type doors.
4. The air vestibule unit of claim 1, wherein a distance through
the passage is about 6 inches or greater.
5. The air vestibule unit of claim 1, wherein the air vestibule
includes lateral return air ducts having return air openings at a
bottom end of the air vestibule.
6. The air vestibule unit of claim 1, wherein the system controller
is configured to maintain a partial pressure of moisture in the
passage equal to or higher than a partial pressure of moisture
external to the passage.
7. The air vestibule unit of claim 1, wherein the controller is
configured to cycle the temperature conditioning device on and
off.
8. The air vestibule unit of claim 1, wherein the air moving device
and temperature conditioning device are positioned in an upper
portion of the air vestibule.
9. The air vestibule unit of claim 1, wherein the air vestibule
includes side portions arranged vertically along opposite sides of
the passage.
10. A method of controlling air condition in an air vestibule unit,
the method comprising: providing an air vestibule defining a
passage; positioning the air vestibule between a first room and a
second room, the first room being warmer than the second room, the
vestibule providing access between the first and second rooms and
being exposed to the first and second rooms; determining an
external partial pressure of moisture vapor external to the
vestibule using only an external temperature and an external
humidity in the first room; determining a vestibule partial
pressure of moisture vapor within the passage of the vestibule
using a vestibule temperature and a vestibule humidity in the
passage; providing heated air to the passage with the air vestibule
to increase the air temperature in the passage when the vestibule
partial pressure of moisture vapor is greater than or equal to the
external partial pressure of moisture vapor.
11. The method of claim 10, wherein the vestibule temperature and
vestibule humidity are measured using a plurality of temperature
sensors and humidity sensors.
12. The method of claim 11, wherein at least one of the temperature
sensors and at least one of the humidity sensors is positioned
outside of the passage.
13. The method of claim 10, wherein the air vestibule includes a
heat source, and the heat source is cycled on and off to provide
the heated air.
14. The method of claim 10, further comprising circulating air in
the vestibule by drawing air from a bottom of the air vestibule
into an air moving device and expelling air from the air moving
device into the passage.
15. The method of claim 10, further comprising moving heated air
into the vestibule using an air moving device.
16. The method of claim 15, wherein the air moved into the
vestibule removes or prevents formation of at least one of ice or
frost in the air vestibule.
17. A non-transitory computer-readable medium having instructions
encoded thereon that, when executed by a processor of a computer,
cause the computer to perform steps comprising: controlling an air
vestibule, the air vestibule being positioned between first and
second rooms, the first room being warmer than the second room, the
air vestibule having a passage that provides access between the
first and second rooms; measuring, with a plurality of thermal
sensors, an external temperature in the first room and a vestibule
temperature within the passage; measuring, with a plurality of
humidity sensors, an external humidity in the first room and a
vestibule humidity within the passage; determining an external
partial pressure of moisture vapor in the first room using the
external temperature and the external humidity only from the first
room; determining a vestibule partial pressure of moisture vapor
within the passage of the vestibule using the vestibule temperature
and the vestibule humidity; delivering heated air to the passage if
the vestibule partial pressure of moisture vapor is greater than or
equal to the external partial pressure of moisture vapor.
18. The non-transitory computer-readable medium of claim 17,
wherein the steps further comprise cycling a heat source on and off
to deliver the heated air.
19. The non-transitory computer-readable medium of claim 17,
wherein the steps further comprise circulating air in the air
vestibule by drawing air from a bottom of the air vestibule and
expelling air into the passage of the air vestibule after being
heated.
20. The non-transitory computer-readable medium of claim 17,
wherein the steps further comprise moving air into a passage of the
vestibule using an air moving device.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application cross-references and claims the benefit of
priority of U.S. Provisional Patent Application No. 62/067,346,
filed 22 Oct. 2014, entitled PUSH-THROUGH CONDITIONED AIR VESTIBULE
AND CONTROLLER, the disclosure of which is incorporated, in its
entirety, by this reference.
TECHNICAL FIELD
[0002] The present invention relates to a conditioned air vestibule
for a cold storage doorway. More particularly, the present
invention relates to an air curtain arrangement and control system
that controls temperature of the air discharged across a doorway
and a method of controlling the airflow temperature to prevent
formation of frost, water, and fog.
BACKGROUND
[0003] In the field of cold storage freezers and similar devices,
various systems such as solid doors, strip curtains, and air
curtains, may be used to separate the cold storage room from an
adjacent relatively warm anteroom. It is desirable to allow traffic
from people and equipment through a doorway between the cold
storage room and the adjacent warm room safely and with a minimum
transfer of relatively cool and warm air between the cold room and
the warm room.
[0004] The use of air curtains is one method of allowing a doorway
to remain open to traffic while also preventing substantial energy
loss between the cold and warm sides of the vestibule. Air curtains
generally direct air across the doorway to counter infiltration of
warm to the cold room and exfiltration of cold air from the cold
room. By way of example, air curtains may direct air horizontally
or vertically across the doorway from or toward an upper portion of
the air curtain.
[0005] As a safety precaution, it is desirable to prevent the
formation of fog, ice, and water in the doorway. Ice may form from
the mixing of air from the cold and warm sides of the vestibule.
The formation of ice at an air curtain depends on the temperature
and relative humidity of the cold and warm rooms, and may be
characterized by a psychrometric saturation curve. The mixing of
air from the relatively warm and cold sides may be characterized by
a straight line between points representing the warm side
temperature and humidity and the cold side temperature and
humidity, which may be plotted on a psychrometric saturation chart
along with the curve. Generally, ice may form whenever the
temperature is below 32 degrees Fahrenheit and the mixing line is
to the left of, and above, the psychrometric saturation curve, as
it is typically plotted.
[0006] The formation of ice may be prevented by heating the air
discharged from the air curtain. By way of example, the discharged
air may be heated to a temperature at a point on the psychrometric
saturation chart such that lines to such point from both the cold
side and warm side temperature/humidity points remain to the right
of, and below, the psychrometric saturation curve, as it is
typically plotted.
[0007] While avoiding the formation of ice, water, and fog, it is
also desirable to operate the air curtain as efficiently as
possible, by adding the minimum amount of heat necessary to avoid
such problems. With respect to the psychrometric saturation chart,
this means keeping the point representing the airstream with the
added heat as close to the saturation curve as possible, without
causing mixing lines from this point to the cold side and warm side
temperature/humidity points to contact or cross the saturation
curve.
[0008] Because temperature and humidity conditions in the cold and
warm side rooms may change, it is desirable in some applications to
dynamically condition the discharged air in response to changing
conditions. Conventional systems have various shortcomings. Some
systems permit operation of the air curtain at points directly on
the saturation curve. In changing environments, this permits the
formation of ice, water, and fog because the system may not respond
as quickly as the conditions change and because the sensors may not
be sufficiently accurate for all positions in the vestibule. This
is particularly a problem for systems that rely upon mathematical
approximations of the psychrometric saturation curve.
SUMMARY
[0009] An aspect of the present disclosure relates to a push
through conditioned air vestibule unit that may comprise an air
vestibule having a top side, a first lateral side, and a second
lateral side that may form a passage through the unit. A plurality
of movable barrier members may be configured to reduce external air
flow through the passage. First and second lateral side supply or
return air ducts may be configured to supply air to or return air
from the top side from the first and second lateral sides. An air
moving device may be configured to circulate, receive, or supply
air from the first and second lateral side return air ducts and to
move air into the passage. The unit may also have a temperature
conditioning device configured to adjust the temperature of air
moved into the passage, an external thermal sensor configured to
measure a temperature external to the passage, an internal thermal
sensor configured to measure a temperature within the passage, an
external humidity sensor configured to measure a humidity external
to the passage, and an internal humidity sensor configured to
measure a humidity internal to the passage. A system controller may
be in communication with the external and internal thermal sensors
and the external and internal humidity sensors and may be
configured to increase the temperature of air moved into the
passage using the temperature conditioning device if the partial
pressure of moisture vapor internal to the passage is not greater
than or equal to the partial pressure of moisture vapor external to
the passage.
[0010] The movable barrier members of the unit may comprise
flexible strips hanging from the top side of the unit and may be
impact-type doors. A distance through the passage may be about 6
inches or greater. The first and second lateral return air ducts
may comprise return air openings at bottom ends of the first and
second lateral sides.
[0011] The system controller may be configured to maintain a
partial pressure of moisture in the passage equal to or higher than
a partial pressure of moisture external to the passage, such as,
for example by being configured to cycle the temperature
conditioning device on and off.
[0012] The air vestibule may be positioned between a first room and
a second room, the first room having a warmer temperature than the
second room. The external thermal sensor and the external humidity
sensor may measure temperature and humidity, respectively, of the
first room.
[0013] In another aspect, a method of controlling air condition in
a conditioned air vestibule unit is provided. The method may
comprise providing a conditioned air vestibule having a heat
source, a plurality of thermal sensors, a plurality of humidity
sensors, and an air moving device, measuring an external
temperature and a vestibule temperature using the plurality of
thermal sensors, measuring an external humidity and a vestibule
humidity using the plurality of humidity sensors, calculating an
external partial pressure of moisture vapor external to the
vestibule, calculating a vestibule partial pressure of moisture
vapor within the vestibule, and enabling the heat source to heat
air provided to the air moving device if the vestibule partial
pressure is greater than or equal to the external partial
pressure.
[0014] The vestibule temperature and vestibule humidity may be
measured within a passage through the conditioned air vestibule.
The external temperature and external humidity may be measured from
an external area warmer than a passage through the conditioned air
vestibule.
[0015] In performing the method, the heat source may be cycled on
and off. The method may further comprise circulating air in the
conditioned air vestibule unit by drawing air from a bottom of the
conditioned air vestibule into the air moving device and expelling
air from the air moving device into the conditioned air vestibule
after being heated by the heat source.
[0016] Air may also be moved into the conditioned air vestibule
using the air moving device. The air moved into the vestibule may
remove or prevent formation of ice and/or frost in the conditioned
air vestibule.
[0017] Some embodiments may comprise a non-transitory
computer-readable medium having instructions encoded thereon that,
when executed by a processor of a computer, cause the computer to
perform steps comprising: measuring an external temperature and a
vestibule temperature of a conditioned air vestibule having a heat
source, a plurality of thermal sensors, a plurality of humidity
sensors, and an air moving device, the external and vestibule
temperatures being measured using the plurality of thermal sensors;
measuring an external humidity and a vestibule humidity using the
plurality of humidity sensors; calculating an external partial
pressure of moisture vapor external to the vestibule; calculating a
vestibule partial pressure of moisture vapor within the vestibule;
and enabling the heat source to heat air provided to the air moving
device if the vestibule partial pressure is greater than or equal
to the external partial pressure.
[0018] The above summary of the present invention is not intended
to describe each embodiment or every implementation of the present
invention. The Figures and the detailed description that follow
more particularly exemplify a preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The accompanying drawings and figures illustrate a number of
exemplary embodiments and are part of the specification. Together
with the present description, these drawings demonstrate and
explain various principles of this disclosure. A further
understanding of the nature and advantages of the present invention
may be realized by reference to the following drawings. In the
appended figures, similar components or features may have the same
reference label.
[0020] FIG. 1 is a perspective view of an example of a push-through
conditioned air vestibule of the present disclosure.
[0021] FIG. 2 is a block diagram of modules implemented by a system
controller of a push-through conditioned air vestibule of the
present disclosure.
[0022] FIG. 3 is a flowchart illustrating an example process by
which a heat source may be controlled in a push-through conditioned
air vestibule.
[0023] FIG. 4 is a block diagram of a computer system that may be
used to implement embodiments of the present disclosure.
[0024] While the embodiments described herein are susceptible to
various modifications and alternative forms, specific embodiments
have been shown by way of example in the drawings and will be
described in detail herein. However, the exemplary embodiments
described herein are not intended to be limited to the particular
forms disclosed. Rather, the instant disclosure covers all
modifications, equivalents, and alternatives falling within the
scope of the appended claims.
DETAILED DESCRIPTION
[0025] Aspects of the present disclosure may improve the
effectiveness of conditioned air vestibules such as those used to
link freezers to warmer areas. These systems may reduce
refrigeration load while preventing frost, ice, and wetness at the
entryway to the vestibule. An example embodiment of the vestibule
may comprise two pairs of impact-type doors, or fixed strips, and
an electrically or hot-gas heated anti-frost air-conditioning (AFC)
section with temperature reset control. In some cases, the
vestibule may be about 6 inches in depth in the direction of travel
through the vestibule. These benefits may reduce refrigeration
losses, increase warehouse (or other commercial or industrial
location) productivity, reduce coil defrosting burdens, and improve
refrigeration cycle efficiency.
[0026] FIG. 1 shows an example of a push-through conditioned air
vestibule 100 according to an embodiment of the present disclosure.
The vestibule 100 comprises a top side 102, a first lateral side
104, and a second lateral side 106 through which a passage 108 is
formed. The passage 108 may be lined with movable barrier members
110 on each end of the passage 108. The first lateral side 104 may
comprise a first air return duct 112, and the second lateral side
106 may comprise a second air return duct 114. These ducts 112, 114
may be configured to bring air to the top side 102 from their
respective lateral sides 104, 106. An air moving device 116 may be
positioned in the top side 102 and configured to receive air from
the return air ducts 112, 114 and then move air into the passage
108, such as through vents exposed into the passage 108 at the top
side 102 of the vestibule 100. The top side 102 may also comprise a
temperature conditioning device 118 that receives airflow and
adjusts the temperature of air moved into the passage 108.
[0027] An external thermal sensor 120 may be configured to measure
a temperature of external air, such as the temperature of a warm
room outside the passage 108, and an internal thermal sensor 122
may be configured to measure the temperature of air in the passage
108. An external humidity sensor 124 and internal humidity sensor
126 may also be configured to measure humidity of their respective
areas relative to the passage 108.
[0028] The vestibule 100 may also include a system controller 128
configured to control the temperature conditioning device 118 and
air moving device 116 while receiving data from the sensors (e.g.,
sensors 120, 122, 124, 126).
[0029] In some embodiments the vestibule 100 may comprise more than
one unit, such as multiple vestibules 100 having aligned passages
in a series. The vestibule 100 may be positioned such that it
separates a cooler area from a warmer area. A common application
would be use of the vestibule 100 as an air curtain between a
freezer and a warm room of a warehouse, for example. In a single
vestibule 100, more than one air curtain may be implemented, such
as a first air curtain directing air primarily toward the first
lateral side 104 and a second air curtain directing air primarily
toward the second lateral side 106 adjacent to the first air
curtain.
[0030] The top side 102 may include a conduit system connecting the
lateral side return air ducts 112, 114 to the air moving device 116
and the temperature conditioning device 118. Positioning the air
moving device 116 and temperature conditioning device 118 in the
top side 102 may be beneficial because the top side 102 is central
to each of the lateral sides 104, 106, so only one air moving
device 116 and/or temperature conditioning device 118 may be
required to receive and control air flow for both lateral sides
104, 106. Additionally, positioning these components 116, 118 in
the top side 102 may reduce the lateral profile of the vestibule
100, thereby either allowing the vestibule 100 to fit within
narrower openings or to maximize the width of the passage 108.
[0031] The top side 102 in FIG. 1 is shown having the controller
128 housed therein, but the controller 128 may alternatively be
stored in another area of the vestibule 100. For example, the
controller 128 may be positioned in one of the lateral sides 104,
106 to be more accessible from the ground level.
[0032] The first lateral side 104 and second lateral side 106,
along with the return air ducts 112, 114, may extend from a ground
level to the top side 102 of the vestibule 100. The return air
ducts 112, 114 may each have a return air vent 130 positioned near
the ground level. At the ground level, the return air vents 130 may
receive cooler air that is moved up through the return air ducts
112, 114 by the air moving device 116 to the top side 102 where its
temperature may be adjusted by the temperature conditioning device
118. In an alternative embodiment, the air discharge openings may
be situated near or in the floor of the air curtain and the return
vents may be situated in or near the upper portion of the air
curtain, such that the air is discharged across the opening in a
generally upward direction.
[0033] The passage 108 may extend between the first and second
lateral sides 104, 106 and may be used as a doorway between rooms
on each side of the vestibule 100. In an example embodiment, the
passage 108 may be about 6 inches across (i.e., between the movable
barrier members 110 at each end of the passage 108). The passage
108 may allow push-through access, meaning personnel, carts,
vehicles, and equipment may push or move through the passage 108
unimpeded.
[0034] The movable barrier members 110 may comprise strips of
flexible material, such as, for example, vinyl strips that hang
from the top side 102 to the ground level. The movable barrier
members 110 may be connected by clips, fasteners, or joints to the
top side 102. In some embodiments the movable barrier members 110
may be referred to as impact-type doors. The movable barrier
members 110 may provide insulation and airflow isolation to the
passage 108 by acting as a barrier to airflow while hanging
vertically, yet may not hinder the passage of equipment and
personnel through the passage 108. Thus, the movable barrier
members 110 may help maintain the temperature and humidity of air
within the passage 108 due to preventing the outflow or inflow of
external air while they close off the ends of the passage 108.
[0035] The air moving device 116 may comprise a device that, when
active, pushes or pulls air through the ducts of the vestibule 100
and through the passage 108. One example air moving device 116 may
comprise a fan or plurality of fans that may be driven by an
electric motor. The motor may be controlled by the system
controller 128 so that the speed and direction of motion of the fan
may be controlled by the controller 128.
[0036] The temperature conditioning device 118 may comprise a
heating or cooling system capable of changing the temperature of
air flowing through the ducts of the vestibule 100. For example, a
temperature conditioning device 118 may comprise a heater
comprising electric coils or heated pipes that warm the air in the
ducts as it passes by the coils or pipes. In some arrangements the
temperature conditioning device 118 may be controllable to output a
desired amount of heat based on commands received from the system
controller 128. In one application, the temperature conditioning
device 118 may beneficially be a heater so that air provided to the
passage 108 may be warmer than air in a cold side of the vestibule
100.
[0037] The heat provided by the temperature conditioning device 118
may also affect the humidity of the air in the ducts and passage
108, so in some configurations the vestibule 100 may further
comprise a humidity conditioning device configured to increase or
decrease the relative humidity of air in the passage 108. In some
embodiments, the humidity conditioning device may expel water or
mist into the air at or near the temperature conditioning device
118.
[0038] The external thermal sensor 120 and internal thermal sensor
122 may comprise thermocouples configured to measure temperature
external or internal to the passage 108. Other types of thermal
sensors may also be used. The external humidity sensor 124 and
internal humidity sensor 126 may comprise electronic hygrometers.
The external thermal sensor 120 and external humidity sensor 124
may be positioned to measure temperature and humidity of a warm
room to the front or rear of the vestibule 100. The internal
thermal and humidity sensors 122, 126 may measure the temperature
and humidity of air in the passage 108.
[0039] The system controller 128 may be a computing device such as,
for example, a computer or integrated control circuit. A computer
system suitable for implementing the system controller 128 is
described in further detail in connection with FIG. 4. The system
controller 128 may comprise a plurality of modules for executing
its functions. As shown in FIG. 2, a system controller 128 may
comprise a vestibule control module 200-a. The vestibule control
module 200-a may comprise a plurality of modules executable by the
system controller 128.
[0040] The vestibule control module 200-a may comprise a
temperature measurement module 205 and a humidity measurement
module 210. The temperature measurement module 205 may be
configured to receive signals from the thermal sensors 120, 122 and
convert the signals into signals readable by a partial pressure
calculation module 215. Likewise, the humidity measurement module
210 may receive signals from the humidity sensors 124, 126 and
convert the signals into a form readable by the partial pressure
calculation module 215.
[0041] A partial pressure calculation module 215 may receive the
signals from the temperature and humidity measurement modules 205,
210 and may implement psychrometric equations to calculate the
partial pressures of moisture vapor in the air of the vestibule and
external to the vestibule. The temperature and relative humidity of
the external area and of the vestibule may be used as inputs to
these equations. In one example embodiment, the following equations
may be implemented:
L.sub.o=C.sub.8/T.sub.o+C.sub.9+C.sub.10T.sub.o+C.sub.11T.sub.o.sup.2+C.-
sub.12T.sub.o.sup.3+C.sub.13/nT.sub.o [Equation 1],
L.sub.i=C.sub.8/T.sub.i+C.sub.9+C.sub.10T.sub.i+C.sub.11T.sub.i.sup.2+C.-
sub.12T.sub.i.sup.3+C.sub.13/nT.sub.i [Equation 2],
P.sub.wso=e.sup.Lo [Equation 3],
P.sub.wsi=e.sup.Li [Equation 4],
P.sub.wo=.PHI..sub.o(P.sub.wso) [Equation 5], and
P.sub.wi=.PHI..sub.i(P.sub.wsi) [Equation 6],
[0042] wherein:
[0043] T.sub.o is the temperature of air in the external area,
T.sub.i is the temperature of air in the vestibule, P.sub.wo is the
partial pressure of vapor in the external area, P.sub.w1 is the
partial pressure of vapor in the vestibule, .PHI..sub.o is the
relative humidity of the external area, .PHI..sub.i is the relative
humidity of the vestibule, P.sub.wso is the saturation pressure of
the external area, P.sub.ws1 is the saturation pressure of the
vestibule, L.sub.o is the natural log of saturation pressure of the
external area, L.sub.i is the natural log of saturation pressure of
the vestibule, C.sub.8=-1.0440397.times.10.sup.4,
C.sub.9=-11.294650, C.sub.10=-2.7022355.times.10.sup.-2,
C.sub.11=1.2890360.times.10.sup.-5,
C.sub.12=-2.4780681.times.10.sup.-9, and C.sub.13=6.5459673. Thus,
the partial pressure calculation module 215 may determine P.sub.wo
and P.sub.wi and provide these values to the comparator module 220.
The comparator module 220 may receive partial pressure calculations
from the partial pressure calculation module 215, compare the
partial pressure values, and send a result to a thermal control
module 225.
[0044] The thermal control module 225 may receive the results of
the comparator module 220 and, via an interface with the air moving
device 116 and the temperature conditioning device 118, may control
the temperature and humidity of air provided to the passage 108 of
the vestibule 100.
[0045] FIG. 3 illustrates an embodiment of a process 300 that may
be executed by the modules of the system controller 128. The
process 300 may include blocks 305 and 310, wherein the temperature
of the air of the external area and the vestibule air are measured.
These temperatures may be measured by the internal and external
thermal sensors 122, 120, respectively. In blocks 315 and 320, the
humidity of the air of the external area and the vestibule air may
be measured, such as by the external and internal humidity sensors
124, 126. At blocks 325 and 330, the system controller 128 may
calculate the partial pressure of moisture vapor in the external
area and in the vestibule. At block 335, the system controller 128
may compare the partial pressures calculated in blocks 325 and 330
and determine whether the partial pressure of moisture vapor in the
vestibule (i.e., PvV) is greater than or equal to the partial
pressure of moisture vapor in the external area (i.e., PvW). If PvV
is less than PvW, the system controller 128 may execute block 340
to enable a heat source. The heat source may be part of the
temperature conditioning device 118. Enabling the heat source may
comprise turning a heat source in the temperature conditioning
device 118 on and off. If PvV is greater than or equal to PvW, the
process 300 may restart and continue to monitor conditions in the
vestibule and external area.
[0046] FIG. 4 depicts a block diagram of a computer system 400
suitable for implementing the present systems and methods. Computer
system 400 includes a bus 405 which interconnects major subsystems
of computer system 400, such as a central processor 410, a system
memory 415 (typically RAM, but which may also include ROM, flash
RAM, or the like), an input/output controller 420, an external
audio device, such as a speaker system 425 via an audio output
interface 430, an external device, such as a display screen 435 via
display adapter 440, an input device 445 (e.g., a keyboard,
touchscreen, etc.) (interfaced with an input controller 450), a
sensor 455 (interfaced with a sensor controller 460), one or more
universal serial bus (USB) device 465 (interfaced with a USB
controller 470), and a storage interface 480 linking to a fixed
disk 475. A network interface 485 is also included and coupled
directly to bus 405.
[0047] Bus 405 allows data communication between central processor
410 and system memory 415, which may include read-only memory (ROM)
or flash memory (neither shown), and random access memory (RAM)
(not shown), as previously noted. The RAM is generally the main
memory into which the operating system and application programs are
loaded. The ROM or flash memory can contain, among other code, the
Basic Input-Output system (BIOS) which controls basic hardware
operation such as the interaction with peripheral components or
devices. For example, a vestibule control module 200-b which may
implement the present systems and methods may be stored within the
system memory 415. Applications resident with computer system 400
are generally stored on and accessed via a non-transitory computer
readable medium, such as a hard disk drive (e.g., fixed disk 475),
an optical drive (e.g., an optical drive that is part of a USB
device 465 or that connects to storage interface 480), or other
storage medium. Additionally, applications can be in the form of
electronic signals modulated in accordance with the application and
data communication technology when accessed via network interface
485.
[0048] Storage interface 480, as with the other storage interfaces
of computer system 400, can connect to a standard computer readable
medium for storage and/or retrieval of information, such as a fixed
disk drive 475. Fixed disk drive 475 may be a part of computer
system 400 or may be separate and accessed through other interface
systems. A modem connected to the network interface 485 may provide
a direct connection to a remote server via a telephone link or to
the Internet via an internet service provider (ISP). Network
interface 485 may provide a direct connection to a remote server
via a direct network link to the Internet via a POP (point of
presence). Network interface 485 may provide such connection using
wireless techniques, including digital cellular telephone
connection, Cellular Digital Packet Data (CDPD) connection, digital
satellite data connection or the like.
[0049] Many other devices or subsystems (not shown) may be
connected in a similar manner (e.g., document scanners, digital
cameras and so on). Conversely, all of the devices shown in FIG. 4
need not be present to practice the present systems and methods.
The devices and subsystems can be interconnected in different ways
from that shown in FIG. 4. The operation of a computer system such
as that shown in FIG. 4 is readily known in the art and is not
discussed in detail in this application. Code to implement the
present disclosure can be stored in a non-transitory
computer-readable medium such as one or more of system memory 415,
or fixed disk 475. The operating system provided on computer system
400 may be MS-DOS.RTM., MS-WINDOWS.RTM., OS/2.RTM., UNIX.RTM.,
Linux.RTM., or another known operating system.
[0050] Moreover, regarding the signals and network communications
described herein, those skilled in the art will recognize that a
signal can be directly transmitted from a first block to a second
block, or a signal can be modified (e.g., amplified, attenuated,
delayed, latched, buffered, inverted, filtered, or otherwise
modified) between the blocks. Although the signals of the above
described embodiments are characterized as transmitted from one
block to the next, other embodiments of the present systems and
methods may include modified signals in place of such directly
transmitted signals as long as the informational and/or functional
aspect of the signal is transmitted between blocks. To some extent,
a signal input at a second block can be conceptualized as a second
signal derived from a first signal output from a first block due to
physical limitations of the circuitry involved (e.g., there will
inevitably be some attenuation and delay). Therefore, as used
herein, a second signal derived from a first signal includes the
first signal or any modifications to the first signal, whether due
to circuit limitations or due to passage through other circuit
elements which do not change the informational and/or final
functional aspect of the first signal.
[0051] The present description provides examples, and is not
limiting of the scope, applicability, or configuration set forth in
the claims. Thus, it will be understood that changes may be made in
the function and arrangement of elements discussed without
departing from the spirit and scope of the disclosure, and various
embodiments may omit, substitute, or add other procedures or
components as appropriate. For instance, the methods described may
be performed in an order different from that described, and various
steps may be added, omitted, or combined. Also, features described
with respect to certain embodiments may be combined in other
embodiments.
[0052] Various inventions have been described herein with reference
to certain specific embodiments and examples. However, they will be
recognized by those skilled in the art that many variations are
possible without departing from the scope and spirit of the
inventions disclosed herein, in that those inventions set forth in
the claims below are intended to cover all variations and
modifications of the inventions disclosed without departing from
the spirit of the inventions. The terms "including" and "having"
come as used in the specification and claims shall have the same
meaning as the term "comprising."
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