U.S. patent application number 12/050473 was filed with the patent office on 2008-11-06 for autonomous ventilation system.
This patent application is currently assigned to Current Energy Controls, LP. Invention is credited to Michael P. Burdett, Daniel Reich.
Application Number | 20080274683 12/050473 |
Document ID | / |
Family ID | 39939851 |
Filed Date | 2008-11-06 |
United States Patent
Application |
20080274683 |
Kind Code |
A1 |
Burdett; Michael P. ; et
al. |
November 6, 2008 |
Autonomous Ventilation System
Abstract
An autonomous ventilation system includes a variable-speed
exhaust fan, a controller, an exhaust hood, and a spillage sensor.
The exhaust fan removes air contaminants from an area. The
controller is coupled to the exhaust fan and adjusts the speed of
the exhaust fan. The exhaust hood is coupled to the exhaust fan and
directs air contaminants to the exhaust fan. The spillage sensor is
coupled to the controller, detects changes in an environmental
parameter in a spillage zone adjacent to the exhaust hood, and
communicates information relating to detected changes in the
environmental parameter to the controller. The controller adjusts
the speed of the exhaust fan in response to information relating to
detected changes in the environmental parameter.
Inventors: |
Burdett; Michael P.;
(Tucson, AZ) ; Reich; Daniel; (Tucson,
AZ) |
Correspondence
Address: |
BAKER BOTTS L.L.P.
2001 ROSS AVENUE, SUITE 600
DALLAS
TX
75201-2980
US
|
Assignee: |
Current Energy Controls, LP
Tucson
AZ
|
Family ID: |
39939851 |
Appl. No.: |
12/050473 |
Filed: |
March 18, 2008 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
60915974 |
May 4, 2007 |
|
|
|
Current U.S.
Class: |
454/61 |
Current CPC
Class: |
F24F 2110/10 20180101;
F24C 15/2042 20130101; F24C 15/2021 20130101; F24F 11/30 20180101;
F24C 15/20 20130101 |
Class at
Publication: |
454/61 |
International
Class: |
F24C 15/20 20060101
F24C015/20 |
Claims
1. An autonomous ventilation system comprising: a variable-speed
exhaust fan operable to remove an air contaminant from an area; a
controller coupled to the variable-speed exhaust fan and operable
to adjust the speed of the exhaust fan; an exhaust hood coupled to
the exhaust fan, the exhaust hood operable to direct the air
contaminant to the exhaust fan; and a spillage sensor coupled to
the controller, the spillage sensor configured to detect a change
in an environmental parameter in a spillage zone adjacent to the
exhaust hood and to communicate information relating to detected
changes in the environmental parameter to the controller, wherein
the controller is further operable to adjust the speed of the fan
in response to information relating to changes in the environmental
parameter detected by the spillage sensor.
2. The ventilation system of claim 1, wherein the exhaust hood is
located above one or more pieces of cooking equipment.
3. The ventilation system of claim 1, wherein the spillage sensor
comprises a temperature sensor.
4. The ventilation system of claim 1, wherein the spillage sensor
comprises an airflow sensor.
5. The ventilation system of claim 1, wherein the air contaminant
comprises one or more of smoke, steam, and fumes.
6. The ventilation system of claim 1 further comprising a
variable-speed supply fan coupled to the controller, the
variable-speed supply fan operable to deliver air to the area.
7. The ventilation system of claim 1 wherein the controller is
further operable to: monitor a piece of equipment below the exhaust
hood to determine if it is has been activated; adjust the
variable-speed exhaust fan to a predetermined minimal speed when
the piece of equipment below the exhaust hood has been turned on;
and turn the variable-speed exhaust fan off when the piece of
equipment below the exhaust fan has been turned off.
8. The ventilation system of claim 7 wherein the predetermined
minimal speed of the variable-speed exhaust fan comprises one of
the following: a minimum capable speed of the variable-speed
exhaust fan; a minimum speed that is calculated to provide a
minimal ventilation rate as required by an applicable standard; a
minimum speed determined by the controller by increasing the speed
of the variable-speed exhaust fan until the spillage sensor
indicates the air contaminant has been removed from the area; and a
minimum speed determined by the controller by decreasing the speed
of the variable-speed exhaust fan until the spillage sensor
indicates the air contaminant has not been removed from the
area.
9. A method of ventilating an area comprising: providing a
controller coupled to a variable-speed exhaust fan, the
variable-speed exhaust fan having an associated exhaust hood and
being operable to remove an air contaminant from an area; providing
a spillage sensor coupled to the controller; sensing a change in an
environmental parameter in a spillage zone adjacent to the exhaust
hood using the spillage sensor; and adjusting the speed of the
variable-speed exhaust fan using the controller based on the
environmental parameter change sensed by the spillage sensor in the
spillage zone adjacent to the exhaust fan.
10. The method of ventilating an area of claim 9, wherein the
exhaust hood is located above one or more pieces of cooking
equipment.
11. The method of ventilating an area of claim 10, wherein: the
environmental parameter change is an increase in temperature in the
spillage zone associated with a spillage air contaminant produced
by the one or more pieces of cooking equipment; and the speed of
the variable-speed exhaust fan is increased to a predetermined
speed in order to remove the spillage air contaminant.
12. The method of ventilating an area of claim 10, wherein: the
environmental parameter change is an increase in airflow in the
spillage zone associated with a spillage air contaminant produced
by the one or more pieces of cooking equipment; and the speed of
the variable-speed exhaust fan is increased to a predetermined
speed in order to remove the spillage air contaminant.
13. The method of ventilating an area of claim 9 further
comprising: determining whether a piece of equipment below the
exhaust hood has been activated; adjusting the variable-speed
exhaust fan to a predetermined minimal speed when the piece of
equipment below the exhaust hood is activated; and turning off the
variable-speed exhaust fan off when the piece of equipment below
the exhaust hood is deactivated.
14. The method of ventilating an area of claim 9 further
comprising: controlling a variable-speed supply fan, the
variable-speed supply fan operable to deliver air from an air
supply source to the area; and adjusting the variable-speed supply
fan based on the speed of the variable-speed exhaust fan.
15. The method of ventilating an area of claim 9, wherein the air
contaminant comprises one or more of smoke, steam, and fumes.
16. The method of ventilating an area of claim 13 wherein the
predetermined minimal speed of the variable-speed exhaust fan
comprises one of the following: a minimum capable speed of the
variable-speed exhaust fan; a minimum speed that is calculated to
provide a minimal ventilation rate as required by an applicable
standard; a minimum speed determined by the controller by
increasing the speed of the variable-speed exhaust fan until the
spillage sensor indicates the air contaminant has been removed from
the area; and a minimum speed determined by the controller by
decreasing the speed of the variable-speed exhaust fan until the
spillage sensor indicates the air contaminant has not been removed
from the area.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit under 35 U.S.C.
.sctn.119(e) of U.S. Provisional Application No. 60/915,974 filed
May 4, 2007 entitled "Smart Kitchen Ventilation Hood."
TECHNICAL FIELD
[0002] This disclosure relates in general to control systems and
more particularly to an autonomous ventilation system.
BACKGROUND
[0003] Ventilation systems are commonly found in modern
residential, restaurant, and commercial kitchens. Heat, smoke, and
fumes are an ordinary byproduct of cooking many foods and must be
removed in order to protect the health and comfort of those present
in the kitchen and adjacent areas. Ventilation systems provide an
effective way to capture excessive heat, smoke, and fumes generated
in kitchens and ventilate them to the atmosphere where they pose no
threat to health or safety.
[0004] A typical ventilation system consists of an exhaust hood
positioned over pieces of cooking equipment that are known to
produce heat, smoke, or fumes. This exhaust hood is usually
connected via ducts to an exhaust fan and in turn to a vent located
on the outside of the building housing the kitchen. The exhaust fan
is operated in a way to create a flow of air from the exhaust hood
to the outside vent. This creates a suction effect at the exhaust
hood that captures the air and any airborne contaminants around the
hood. Consequently, any heat, smoke, or fumes generated by the
cooking equipment will rise up to the overhead exhaust hood where
it will be captured by the suction and transported out of the
kitchen to the outside vent. There, it will dissipate harmlessly
into the atmosphere.
[0005] Most ventilation systems must be manually activated and
deactivated by the user. In a typical fast-food restaurant, for
example, an employee must manually activate the kitchen ventilation
system early in the day or before any cooking occurs. The system
will then remain active in order to capture any smoke or fumes that
may result from cooking. The system must then be manually
deactivated periodically, at the end of the day, or after all
cooking has ceased. This manual operation of the ventilation system
typically results in the system being active at times when
ventilation is not actually required. This needlessly wastes energy
not only associated with the operation of the ventilation system,
but also due to the ventilation of uncontaminated air supplied to
the kitchen by a heating and cooling system. By operating when no
smoke or fumes are present, the ventilation system will remove
other valuable air that was supplied to heat or cool the kitchen
and thus cause the heating and cooling system to operate longer
than it would have otherwise.
SUMMARY OF THE DISCLOSURE
[0006] The present disclosure provides an autonomous ventilation
system that substantially eliminates or reduces at least some of
the disadvantages and problems associated with previous methods and
systems.
[0007] According to one embodiment, an autonomous ventilation
system includes a variable-speed exhaust fan, a controller, an
exhaust hood, and a spillage sensor. The exhaust fan removes air
contaminants from an area. The controller is coupled to the exhaust
fan and adjusts the speed of the exhaust fan. The exhaust hood is
coupled to the exhaust fan and directs air contaminants to the
exhaust fan. The spillage sensor is coupled to the controller,
detects changes in an environmental parameter in a spillage zone
adjacent to the exhaust hood, and communicates information relating
to detected changes in the environmental parameter to the
controller. The controller adjusts the speed of the exhaust fan in
response to information relating to changes in the environmental
parameter detected by the spillage sensor.
[0008] Technical advantages of certain embodiments may include a
reduction in energy consumption, an increase in the comfort of the
ventilated area, a decrease in noise, and an increase in the
lifespan of environmental sensors and fans. Embodiments may
eliminate certain inefficiencies such as needlessly ventilating
valuable air from an area that was supplied by a heating,
ventilation, and air conditioning ("HVAC") system.
[0009] Other technical advantages will be readily apparent to one
skilled in the art from the following figures, descriptions, and
claims. Moreover, while specific advantages have been enumerated
above, various embodiments may include all, some, or none of the
enumerated advantages.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] For a more complete understanding of the present disclosure
and its advantages, reference is now made to the following
description, taken in conjunction with the accompanying drawings,
in which:
[0011] FIG. 1 is a simplified block diagram illustrating a facility
requiring ventilation in accordance with a particular
embodiment;
[0012] FIGS. 2A and 2B are simplified block diagrams illustrating a
ventilation system in accordance with a particular embodiment;
[0013] FIGS. 3A and 3B are various views of a spillage probe
assembly in accordance with a particular embodiment;
[0014] FIG. 4 is a method of controlling a ventilation system in
accordance with a particular embodiment.
DETAILED DESCRIPTION OF THE DISCLOSURE
[0015] FIG. 1 depicts a facility 100 where a particular embodiment
may be utilized. Facility 100 may be a restaurant, for example,
that includes a kitchen 102 and at least one adjacent room 104
separated by a wall 106. Wall 106 contains a doorway 108 that
allows access between kitchen 102 and adjacent room 104. Facility
100 also includes an HVAC system 110 that provides conditioned air
to the interior of facility 100 via interior vents 112. Kitchen 102
includes one or more pieces of cooking equipment 114, an exhaust
hood 116, a ceiling supply air vent 118, and a ceiling exhaust vent
124. Examples of cooking equipment 114 include, but are not limited
to, stoves, cooktops, ovens, fryers, and broilers. Exhaust hood 116
is oriented such that a downward-facing opening 120 is operable to
direct an air contaminant 122 associated with the operation of
cooking equipment 114 through ceiling exhaust vent 124 and
ultimately out an exterior exhaust vent 130 via an exhaust duct
132. Air contaminant 122 includes, but is not limited to, smoke,
steam, fumes, and/or heat. Ceiling supply air vent 118 is connected
to a supply air duct 134 and is operable to provide supply air 126.
Supply air 126 may be supplied from HVAC system 110 and may include
conditioned air (i.e., heated or cooled air) or unconditioned air.
Supply air 126 may be supplied in an amount corresponding to the
amount of air removed from kitchen 102 via exhaust hood 116 such
that the air pressure inside kitchen 102 remains relatively
constant and positive in relation to outside pressure.
[0016] Removing air contaminants 122 from kitchen 102 helps ensure
that kitchen 102, as well as adjacent room 104, remains safe,
sufficiently free of air contaminants 122, and at a comfortable
temperature for anyone inside. The volume of air exhausted via
exhaust hood 116 should be carefully regulated to minimize the
quantity of conditioned air (air entering facility 100 through HVAC
system 110) that is vacated from kitchen 102 and facility 100 while
ensuring that enough air is ventilated to prevent buildup of air
contaminants 122. Because a particular piece of cooking equipment
114 may not be in use at all times and thus will not continuously
generate air contaminants 122, it becomes beneficial to vary the
rate at which exhaust hood 116 ventilates air contaminants 122 from
kitchen 102 as well as the rate at which ceiling supply air vent
118 supplies air to kitchen 102 as a means to conserve energy and
increase occupant safety and comfort. The embodiments discussed
below provide a convenient alternative to manually activating a
ventilation system as the level of air contaminants fluctuates.
[0017] While facility 100 has been described in reference to a
restaurant, it should be noted that there are many facilities in
need of such ventilation systems. Such facilities include
manufacturing facilities, industrial facilities, residential
kitchens, and the like. Likewise, embodiments in this disclosure
are described in reference to kitchen 102, but could be utilized in
any facility requiring ventilation.
[0018] FIGS. 2A and 2B depict an autonomous ventilation system 200
as would be located inside kitchen 102 in accordance with a
particular embodiment. Autonomous ventilation system 200 includes
exhaust hood 116 with downward-facing opening 120. Exhaust hood 116
is coupled to ceiling exhaust vent 124 and is positioned above one
or more pieces of cooking equipment 114. Air is drawn up through
exhaust hood 116 via downward-facing opening 120 by an exhaust fan
210. Exhaust fan 210 may be positioned anywhere that allows it to
draw air up through exhaust hood 116 including, but not limited to,
inside exhaust hood 116 and exhaust duct 132. Autonomous
ventilation system 200 also includes ceiling supply air vent 118
that can supply conditioned or unconditioned air to kitchen 102
from HVAC system 110. Air is supplied to kitchen 102 by a supply
air fan 212 that is located in a position so as to create a flow of
air through supply air duct 134 and ultimately out ceiling supply
air vent 118.
[0019] Autonomous ventilation system 200 also includes a spillage
probe assembly 214 containing one or more spillage sensors 230 (not
pictured in FIGS. 2A or 2B) operable to measure environmental
parameters in or about a spillage zone 216. Environmental
parameters measured by spillage sensors 230 may include, but are
not limited to, one or more of temperature, air flow, vapor
presence, and/or fume presence. Spillage zone 216 envelops an area
that is adjacent to exhaust hood 116 but is not directly beneath
exhaust hood 116. If the ventilation rate of autonomous ventilation
system 200 is insufficient to capture and remove all air
contaminants 122 associated with the operation of cooking equipment
114, spillage air contaminants 128 will spill out of exhaust hood
116 and pass upward through spillage zone 216. It should be noted
that the dimensions of spillage zone 216 are just an example used
for purposes of illustration and that spillage zone 216 may have
different dimensions depending on the cooking environment.
[0020] Spillage probe assembly 214 also contains a termination box
224, and in some embodiments, an override button 226. The one or
more spillage sensors 230 are coupled to termination box 224. In
some embodiments, override button 226 is also coupled to
termination box 224. Override button 226, however, may be located
on spillage probe assembly 214, exhaust hood 116, or any other
location that is accessible to a user.
[0021] Autonomous ventilation system 200 is controlled by a
controller 220. As an example only, controller 220 may consist of
the Kontar MC8 process controller manufactured by Current Energy,
Inc. However, any suitable controller may be used. Controller 220
is coupled to exhaust fan 210, supply air fan 212, cooking
equipment 114, an exhaust temperature sensor (not pictured), an
ambient kitchen temperature sensor 228, override button 226, and/or
one or more spillage sensors 230. Controller 220 receives
information from spillage sensors 230 to determine fluctuations in
an environmental parameter(s) in spillage zone 216. Controller 220
also communicates with exhaust fan 210 to control its speed and
consequently the rate of ventilation of autonomous ventilation
system 200. In some embodiments, controller 220 additionally
communicates with supply air fan 212 to control its speed and thus
the amount of air that is re-supplied to kitchen 102. Controller
220 may also be coupled to cooking equipment 114 in order to
determine when it has been turned on and off.
[0022] In operation, autonomous ventilation system 200
automatically starts and stops according to a predetermined
schedule and/or by sensing the activation of cooking equipment 114
under exhaust hood 116. In addition, the ventilation rate of
autonomous ventilation system 200 automatically adjusts according
to fluctuations in one or more environmental parameters in spillage
zone 216 as sensed by spillage sensors 230. Additionally or
alternatively, a user may manually control autonomous ventilation
system 200 by momentarily pressing override button 226.
[0023] First, autonomous ventilation system 200 may automatically
start and stop according to a predetermined schedule. A user may
configure a schedule or modify an existing schedule through a local
or remote interface to controller 220. Controller 220, in turn, may
turn exhaust fan 210 on and off and/or adjust its speed based on
this predetermined schedule. Additionally or alternatively,
controller 220 may turn exhaust fan 210 on and off and/or adjust
its speed based on the state of cooking equipment 114 under exhaust
hood 116. In one embodiment, for example, controller 220 may be
coupled to cooking equipment 114 in order to detect when it has
been activated. In such an embodiment, controller 220 may turn on
exhaust fan 210 when cooking equipment 114 has been activated, and
may turn off exhaust fan 210 when cooking equipment 114 has been
deactivated. By automatically starting and stopping according to a
predetermined schedule and/or the state of cooking equipment 114,
autonomous ventilation system 200 provides increased energy
efficiency and comfort level while minimizing unnecessary noise and
ventilation of conditioned air.
[0024] Additionally, controller 220 may turn exhaust fan 210 on and
off and/or adjust its speed based on fluctuations in an
environmental parameter in spillage zone 216 due to spillage air
contaminants 128. In one embodiment, for example, spillage probe
assembly 214 contains one or more spillage sensors 230 that measure
the temperature of spillage zone 216. As an example only, spillage
sensors 230 may consist of the Betatherm G10K3976AIG1 thermistor.
In this embodiment, controller 220 may communicate with an ambient
kitchen temperature sensor 228 to determine the ambient temperature
of kitchen 102 away from the spillage zone (e.g., receive
temperature measurements from sensors) and with spillage sensors
230 of spillage probe assembly 214 to determine the temperature of
spillage zone 216. Controller 220 may then compare the temperature
of spillage zone 216 with that of kitchen 102 to determine if the
difference in temperature has reached or exceeded a predetermined
amount, for example, two degrees Fahrenheit. If, for example, the
temperature of spillage zone 216 exceeds the temperature of kitchen
102 by this predetermined amount (or any other suitable amount),
controller 220 may accelerate the speed of exhaust fan 210 to
increase the ventilation rate of autonomous ventilation system 200
and eliminate spillage air contaminants 128. Controller 220 may
maintain this increased ventilation rate for a predetermined period
of time or until it is determined that the increased rate is no
longer needed. For example, controller 220 may decrease the speed
or deactivate exhaust fan 210 when the difference in temperature
between kitchen 102 and spillage zone 216 returns to a value that
is less than the predetermined amount. By automatically adjusting
its ventilation rate based on environmental parameters in spillage
zone 216, autonomous ventilation system 200 alleviates
disadvantages of other ventilation systems such as wasted energy
and unnecessary noise. In addition, by locating spillage sensors
230 in spillage zone 216 outside of exhaust hood 116, the sensors
are less susceptible to normal deterioration and corrosion caused
by air contaminants 122. As a result, spillage sensors 230 require
less cleaning and maintenance and will have a longer life.
[0025] In another embodiment, spillage probe assembly 214 may
contain one or more spillage sensors 230 that measure bidirectional
airflow through spillage zone 216. In this embodiment, spillage
sensors 230 are orientated in such a way as to detect air flow in
the up and down directions through spillage zone 216. If the
ventilation rate of autonomous ventilation system 200 is
insufficient to capture and remove all air contaminants 122
associated with the operation of cooking equipment 114, spillage
air contaminants 128 will spill out of exhaust hood 116 and pass
through spillage zone 216 creating an upward flow of air.
Controller 220 may detect this upward flow of air by receiving
airflow measurements from spillage sensors 230. If the flow of air
up through spillage zone 216 reaches or exceeds a predetermined
amount, controller 220 may accelerate the speed of exhaust fan 210
to increase the ventilation rate of autonomous ventilation system
200 and eliminate or reduce spillage air contaminants 128.
Controller 220 may then decrease the ventilation rate after a
predetermined period of time or after it detects with spillage
sensors 230 that there is no longer a flow of air up through
spillage zone 216 equal to or greater than the predetermined
amount.
[0026] In some embodiments, controller 220 may additionally or
alternatively adjust the speed of exhaust fan 210 based on the
state of override button 226. In this embodiment, a user may
momentarily push override button 226 in order to manually control
the speed of exhaust fan 210 and thus the ventilation rate of
autonomous ventilation system 200. For example, if exhaust fan 210
is not on, a user may press override button 226 in order to
activate autonomous ventilation system 200 for a predetermined
amount of time. If exhaust fan 210 is already on, a user may press
override button 226 in order to accelerate the ventilation rate of
autonomous ventilation system 200 for a predetermined amount of
time. In some embodiments, there may be more than one override
button 226. In these embodiments, override buttons 226 may provide
the user a means to turn autonomous ventilation system 200 on
and/or off, increase and/or decrease the ventilation rate, or any
combination of the proceeding. The one or more override buttons 226
provide the user with a means of manual control over autonomous
ventilation system 200 when desired.
[0027] In some embodiments, controller 220 may also automatically
control the speed of supply air fan 212 to provide a desired
pressurization of kitchen 102. For example, it may set the speed of
supply air fan 212 to match the speed of exhaust fan 210. As a
result, the rate at which air is removed and supplied to kitchen
102 is approximately equal and thus the temperature and air
pressure remains relatively constant. Controller 220 may also set
the speed of supply air fan 212 to a speed that is greater than the
speed of exhaust fan 210 to create positive pressure in kitchen
102. Additionally or alternatively, controller 220 may set the
speed of supply air fan 212 to a speed that is less than the speed
of exhaust fan 210 to create negative pressure in kitchen 102. This
ensures that the environment in kitchen 102 remains safe and
comfortable regardless of how much air is being ventilated through
exhaust hood 116.
[0028] Exhaust fan 210 and supply air fan 212 may be powered by
various types of motors including, but not limited to, AC
single-phase electrical motors, AC three-phase electrical motors,
and DC electrical motors. The speeds of exhaust fan 210 and supply
air fan 212 may be adjusted by controller 220 by modulating the
frequency of the output of a variable frequency drive in the case
of AC single-phase or three-phase electrical motors, by a phase cut
modulation technique in the case of a single-phase motor, or by
changing voltage in case of a DC electrical motor.
[0029] Modifications, additions, or omissions may be made to
autonomous ventilation system 200 and the described components. As
an example, while FIG. 2 depicts one piece of cooking equipment 114
and one spillage zone 216, autonomous ventilation system 200 may be
modified to include any number and combination of these items.
Additionally, while certain embodiments have been described in
detail, numerous changes, substitutions, variations, alterations
and modifications may be ascertained by those skilled in the art.
For example, while autonomous ventilation systems 200 has been
described in reference to kitchen 102 and cooking equipment 114,
certain embodiments may be utilized in other facilities where
ventilation is needed. Such facilities include manufacturing
facilities, industrial facilities, residential kitchens, and the
like. It is intended that the present disclosure encompass all such
changes, substitutions, variations, alterations and modifications
as falling within the spirit and scope of the appended claims.
[0030] FIGS. 3A and 3B depict an example spillage probe assembly
300, which could be utilized as spillage probe assembly 214,
discussed above in connection with FIGS. 2A and 2B. FIG. 3A
provides a front view of spillage probe assembly 300, and FIG. 3B
provides a back view of spillage probe assembly 300.
[0031] Spillage probe assembly 300 includes a housing 302, a
tensioned cable 304, one or more spillage sensors 230, a
termination box 224, and an override button 226. The one or more
spillage sensors 230 and override button 226 are coupled to
termination box 224, which may in turn be coupled to controller 220
(not pictured). Tensioned cable 304 is coupled to housing 302 and
provides support to spillage sensors 230. Tensioned cable 304
suspends spillage sensors 230 in spillage zone 216 and isolates
them from housing 302. Spillage sensors 230 are attached to
tensioned cable 304 in such a way that allows a user to slide the
sensors on tensioned cable 304 to a location that is above a piece
of equipment such as cooking equipment 114 below exhaust hood 116.
Tensioned cable 304 may be any material including, but not limited
to, metal and/or plastic. In some embodiments, tensioned cable 304
may be replaced with any other suitable means of supporting
spillage sensors 230 and isolating them from housing 302.
[0032] In operation, spillage probe assembly 300 is mounted to
exhaust hood 116 in a manner that allows spillage sensors 230 to
monitor spillage zone 216. Spillage probe assembly 300 is mounted
to exhaust hood 116 with fasteners via mounting holes 306. Once
mounted in the appropriate position above a piece of equipment such
as cooking equipment 114, a user may manually adjust the position
of one or more spillage sensors 230 by sliding them along tensioned
cable 304 so that they are located over the piece of equipment to
be monitored. Once in the desired position, spillage sensors 230
communicate information relating to detected changes in
environmental parameters in spillage zone 216 to controller 220.
For example, if the ventilation rate of autonomous ventilation
system 200 is insufficient to capture and remove all air
contaminants 122 associated with the operation of cooking equipment
114, spillage air contaminants 128 will spill out of exhaust hood
116 and pass through spillage zone 216. Spillage sensors 230 may
detect spillage air contaminants 128 in a manner as described above
in reference to FIGS. 2A and 2B and communicate the information to
controller 220. Controller 220 may then automatically adjust the
speed of exhaust fan 210 and thus the ventilation rate of the
autonomous ventilation system.
[0033] Modifications, additions, or omissions may be made to
spillage probe assembly 300 and the described components. As an
example, spillage probe assembly 300 as seen in FIG. 3B includes
two spillage sensors 230. It should be noted, however, that
spillage probe assembly 300 may include any number of spillage
sensors 230. Also, FIG. 3A depicts override button 226 coupled to
termination box 224. Override button 226, however, may be coupled
to spillage probe assembly 300 in another location, or any location
on autonomous ventilation system 200 that is accessible to the
user. Additionally, while certain embodiments have been described
in detail, numerous changes, substitutions, variations, alterations
and modifications may be ascertained by those skilled in the art,
and it is intended that the present disclosure encompass all such
changes, substitutions, variations, alterations and modifications
as falling within the spirit and scope of the appended claims.
[0034] With reference now to FIG. 4, an example autonomous
ventilation control method 400 is provided. Autonomous ventilation
control method 400 may be implemented, for example, by controller
220 described in reference to autonomous ventilation system 200 in
FIGS. 2A and 2B above. Autonomous ventilation control method 400
will now be described in reference to controller 220 as utilized by
autonomous ventilation system 200 in kitchen 102. It must be noted,
however, that autonomous ventilation control method 400 may be
utilized by any controller to control a ventilation system
regardless of location.
[0035] Autonomous ventilation control method 400 comprises three
main states: OFF, LOW, and HIGH. In OFF state 402, controller 220
turns off exhaust fan 210 where it is not ventilating air from
kitchen 102 via exhaust hood 116. In LOW state 410, controller 220
sets the speed of exhaust fan 210 to a minimal speed, Qmin, as will
be described in more detail below. In HIGH state 422, controller
220 sets the speed of exhaust fan 210 to a maximum speed, Qmax.
[0036] Autonomous ventilation control method 400 begins in OFF
state 402. While in OFF state 402, exhaust fan 210 is turned off.
However, autonomous ventilation control method 400 will transition
to LOW state 410, where the speed of exhaust fan 210 is set to
minimum speed Qmin, if various events occur. Such events may
include event 404 where a user presses override button 226, event
405 where a scheduled start time arrives, event 406 where cooking
equipment 114 is turned on, or event 408 where an environmental
parameter in spillage zone 216 meets or exceeds a predetermined
threshold. Conversely, autonomous ventilation control method 400
will transition from LOW state 410 to OFF state 402 if other events
occur. These events include event 412 where cooking equipment 114
is turned off, event 414 where a scheduled stop time arrives, event
416 where a period of time elapses after a user pushes override
button 226, and/or event 417 where when the environmental parameter
in spillage zone 216 returns to normal.
[0037] In event 404, a user pushes override button 226 while
autonomous ventilation control method 400 is in OFF state 402 and
exhaust fan 210 is off. Override button 226 is provided to give the
user manual control of autonomous ventilation system 200. When the
user presses override button 226 while exhaust fan 210 is off,
autonomous ventilation control method 400 will transition to LOW
state 410 in order to turn on exhaust fan 210 and ventilate the
area. In some embodiments, a timer is started when the user pushes
override button 226 in event 404. In event 416, this override
button timer expires according to a predetermined, but
configurable, amount of time and autonomous ventilation control
method 400 transitions from LOW state 410 back to OFF state 402. By
monitoring the activity of override button 226, autonomous
ventilation control method 400 provides the user a manual means by
which to control autonomous ventilation system 200.
[0038] In event 405, a predetermined scheduled start time arrives.
A user may interface with controller 220 to establish scheduled
times for autonomous ventilation system 200 to turn on.
Predetermined start times may also be preprogrammed into autonomous
ventilation system 200. When a scheduled start time arrives in
event 405, autonomous ventilation control method 400 will
transition from OFF state 402 to LOW state 410 in order to turn on
exhaust fan 210 and set its speed to Qmin. Conversely, a user may
interface with controller 220 to establish scheduled times for
autonomous ventilation system 200 to turn off, and/or stop times
may be preprogrammed into autonomous ventilation system 200. In
event 414, a scheduled stop time arrives while autonomous
ventilation control method 400 is in LOW state 410. If event 414
occurs, autonomous ventilation control method 400 will transition
to OFF state 402 where exhaust fan 210 is set to off.
[0039] In event 406, cooking equipment 114 below exhaust hood 116
is turned on while autonomous ventilation control method 400 is in
OFF state 402 and exhaust fan 210 is off. If autonomous ventilation
control method 400 determines that cooking equipment 114 has been
turned on but exhaust fan 210 is off, it will transition to LOW
state 410 and set the speed of exhaust fan 210 to Qmin. Conversely,
event 412 occurs when cooking equipment 114 below exhaust hood 116
is turned off while autonomous ventilation control method 400 is in
LOW state 410. If autonomous ventilation control method 400
determines that event 412 has occurred, it will transition from LOW
state 410 to OFF state 402 and turn off exhaust fan 210.
[0040] In event 408, an environmental parameter in spillage zone
216 meets or exceeds a predetermined threshold while autonomous
ventilation control method 400 is in OFF state 402. Autonomous
ventilation control method 400 may determine by communicating with
one or more spillage sensors 230 that an environmental parameter in
spillage zone 216 has changed sufficiently to warrant the
activation of exhaust fan 210. Such environmental parameters may
include temperature and airflow as previously described in
reference to FIGS. 2A and 2B above. If, for example, spillage
sensors 230 are temperature sensors, event 408 would occur when the
temperature of spillage zone 216 exceeds that of kitchen 102 by a
predetermined, but configurable, amount. If autonomous ventilation
control method 400 determines that this event has occurred while it
is in OFF state 402, it will transition to LOW state 410 and set
the speed of exhaust fan 210 to Qmin. Conversely, event 417 occurs
when autonomous ventilation control method 400 is in LOW state 410
and the environmental parameter in spillage zone 216 returns to
normal. If autonomous ventilation control method 400 determines
that event 417 has occurred, it will transition back to OFF state
402 and turn off exhaust fan 210.
[0041] Autonomous ventilation control method 400 also includes HIGH
state 422. While in HIGH state 422, exhaust fan 210 is set to its
maximum speed, Qmax. Autonomous ventilation control method 400 will
transition to HIGH state 422 from LOW state 410 when various events
occur. Such events include event 418 where a user presses override
button 226, and event 420 where an environmental parameter in
spillage zone 216 meets or exceeds a predetermined threshold.
Conversely, autonomous ventilation control method 400 will
transition from HIGH state 422 to LOW state 410 and set the speed
of exhaust fan 210 to Qmin if other events occur. Such events
include event 424 where a period of time elapses after an
environmental parameter in spillage zone exceeds a threshold, event
426 where an environmental parameter in spillage zone returns to
normal, and/or a period of time elapses after a user pushes
override button 226 in event 428. Similarly, autonomous ventilation
control method 400 will transition from HIGH state 422 to OFF state
410 if a scheduled stop time arrives in event 430.
[0042] In event 418, a user pushes override button 226 while
autonomous ventilation control method 400 is in LOW state 410 and
exhaust fan 210 is set to Qmin. When a user presses override button
226 while exhaust fan 210 is already set to Qmin, autonomous
ventilation control method 400 will transition to HIGH state 422 in
order to set exhaust fan 210 to its maximum rate Qmax and ventilate
the area. In some embodiments, a timer is started when the user
pushes override button 226 in event 418. In event 428, this
override button timer expires according to a predetermined, but
configurable, amount of time and autonomous ventilation control
method 400 transitions from HIGH state 410 back to LOW state 410.
By monitoring the activity of override button 226, autonomous
ventilation control method 400 provides the user a manual means by
which to control autonomous ventilation system 200.
[0043] In event 420, an environmental parameter in spillage zone
216 meets or exceeds a predetermined threshold while autonomous
ventilation control method 400 is in LOW state 410. If, for
example, spillage sensors 230 are comprised of temperature sensors,
event 420 will occur when autonomous ventilation control method 400
determines that the temperature of spillage zone 216 exceeds that
of kitchen 102 by a predetermined amount. If autonomous ventilation
control method 400 determines that this event has occurred while it
is in LOW state 410, it will transition to HIGH state 422 and set
the speed of exhaust fan 210 to Qmax. In some embodiments, this
transition from Qmin to Qmax may be instantaneous. In other
embodiments, however, the transition may be gradual and/or
stair-stepped and may not actually reach Qmax if conditions in
spillage zone 216 return to normal during the transition.
[0044] Conversely, event 426 occurs when autonomous ventilation
control method 400 is in HIGH state 422 and the environmental
parameter in spillage zone 216 returns to normal. If autonomous
ventilation control method 400 determines that event 426 has
occurred, it will transition back to LOW state 410 and set the
speed of exhaust fan 210 to Qmin. In some embodiments, autonomous
ventilation control method 400 may set a timer after an
environmental parameter in spillage zone 216 meets or exceeds a
predetermined threshold in event 420. In event 424, this spillage
timer expires according to a predetermined, but configurable,
amount of time. If autonomous ventilation control method 400
determines that this timer has expired in event 424, it may then
transition from HIGH state 422 back to LOW state 410 and set the
speed of exhaust fan 210 back to Qmin.
[0045] In event 430, a predetermined scheduled stop time arrives in
a similar manner as event 414. When a scheduled stop time arrives
in event 430, ventilation control method 400 will transition from
HIGH state 422 to OFF state 402 in order to turn off exhaust fan
210.
[0046] The minimal speed, Qmin, for exhaust fan 210 may be
determined by various methods. Initially, Qmin may be preprogrammed
to be the lowest capable speed of exhaust fan 210, or it may be a
speed that is calculated to provide the minimal amount of
ventilation as required by applicable standards. However, Qmin may
be automatically adjusted by autonomous ventilation control method
400. For example, if the temperature of spillage zone 216 exceeds
that of kitchen 102 by a predetermined amount in event 420,
autonomous ventilation control method 400 may gradually increase
the speed of exhaust fan 210 from Qmin. It may continually monitor
the temperature of spillage zone 216 while it is increasing the
speed to determine the speed at which the difference in temperature
drops to an acceptable level. It may then record this speed as the
new Qmin and use it whenever it is in LOW state 410. In addition or
alternatively, a user may initiate a recalibration of Qmin through
a local or remote interface while all cooking equipment 114 under
exhaust hood 116 is idle. In this procedure, autonomous ventilation
control method 400 gradually decreases the speed of exhaust fan 210
from Qmax until the temperature in spillage zone 216 begins to
rise. It may then record the speed of exhaust fan 210 at the point
the temperature started rising and use it as the new Qmin.
[0047] The speed Qmax of exhaust fan 210 is the maximum operating
speed of the fan. This speed may be predetermined and/or preset by
the manufacturer. In some embodiments, Qmax may be controlled/set
by a user through a local or remote interface.
[0048] While a particular autonomous ventilation control method 400
has been described, it should be noted that certain steps may be
rearranged, modified, or eliminated where appropriate.
Additionally, while certain embodiments have been described in
detail, numerous changes, substitutions, variations, alterations
and modifications may be ascertained by those skilled in the art,
and it is intended that the present disclosure encompass all such
changes, substitutions, variations, alterations and modifications
as falling within the spirit and scope of the appended claims.
* * * * *