Autonomous ventilation system
Contents
1. or in any other position that allows it to detect IR index fluctuations in cooking zone 216 beneath exhaust hood 116 jai 5 20 40 45 55 4 Cooking zone 116 may envelop an area adjacent to cooking equipment 114 or any portion of cooking equipment 114 Autonomous ventilation system 200 is controlled by a controller 220 Controller 220 is coupled to IR sensor 214 exhaust fan 210 supply air fan 212 and or cooking equip ment 114 Controller 220 has auto calibration and control logic that may be heuristically adjusted from observation of the environment as discussed below Controller 220 commu nicates with IR sensor 214 to observe the environment and determine IR index fluctuations in or about cooking 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 In operation controller 220 automatically adjusts the speed of exhaust fan 210 and thus the ventilation rate of autonomous ventilation system 200 based on a schedule and or certain conditions sensed by IR sensor 214 These condi tions may include the energy level of cooking equipment2. 114 the state of IR sensor 214 the introduction of uncooked food into cooking zone 216 and or the presence of excessive amounts of air contaminant 122 First controller 220 may turn exhaust fan 210 on and off and or adjust its speed based on the energy level of cooking equipment 114 Controller 220 may observe cooking equip ment 114 with IR sensor 214 and determine an average IR index for the cooking surface or cooking medium when it is not in use When a user then activates cooking equipment 114 controller 220 may detect via IR sensor 214 the increase in the IR index of the cooking surface or the cooking medium and set the rate of exhaust fan 210 to an idle rate This idle rate may bea fixed predetermined speed or it may bea speed based on the IR index as measured by IR sensor 214 Conversely controller 220 may decrease the speed or completely turn off exhaust fan 210 when it is determined via IR sensor 214 that cooking equipment 114 has been turned off To determine if cooking equipment 114 has been turned off controller 220 may determine that the IR index of the cooking surface or cooking medium of cooking equipment 114 has decreased to or towards the typical IR index when not in use In some embodiments controller 220 may be additionally or alterna tively coupled to cooking equipment 114 to detect when it has been activated and deactivated By automatically controlling the ventilation rate based on the energy level of cooking equipmen
3. 2003 0104778 Al 6 2003 Liu 5 042 453 A 8 1991 Shellenberger 2003 0146082 Al 8 2003 Gibson et al 5 042 456 A 8 1991 Cote 2003 0207662 Al 11 2003 Liu 5 050 581 A 9 1991 Roehl Hager 2003 0210340 Al 11 2003 Romanowich 348 272 5 063 834 A 11 1991 Aalto 2004 0011349 Al 1 2004 Livchak et al US 8 795 040 B2 Page 3 56 References Cited FR 2705766 2 1994 GB 1544445 4 1979 U S PATENT DOCUMENTS GB 2054143 2 1981 GB 2132335 7 1984 2005 0007578 Al 1 2005 Zieminsetal 356 153 GB 2266340 10 1993 2005 0098640 Al 5 2005 Ichishi etal 236 493 HK 1019417 2 2000 2005 0115557 Al 6 2005 Meredith JP 51 132645 11 1976 2005 0229922 Al 10 2005 Magner et al JP 60 213753 10 1985 2005 0279845 Al 12 2005 Bagwell et al JP 63 091442 4 1988 2006 0009147 Al 1 2006 Huang et al JP 63 251741 10 1988 2006 0032492 Al 2 2006 Bagwell et al JP 10 084039 3 1989 2006 0060187 Al 3 2006 Luddy et al JP 02 033552 2 1990 2006 0219235 Al 10 2006 Bagwell et al JP 32 047937 11 1991 2006 0278216 Al 12 2006 Gagas et al 126 299D JP 40 000140 1 1992 2007 0001111 A1 1 2007 Rueb et al 250 236 JP 40 062347 2 1992 2007 0015449 Al 1 2007 Livchak et al JP 40 068242 3 1992 2007 0023349 Al 2 2007 Kyllonen et al JP 41 013143 4 1992 2007 0068509 Al 3 2007 Bagwell et al JP 52 048645 9 1993 2007 0165353 Al 7 2007 Fleischer JP 10 288371 10 1998 2007 0183154 Al 8 2007 Robson JP H11 514734 12 1999 2007 0184771 A
4. 210 based on a schedule or certain conditions sensed by IR sensors 214 in a similar manner as described above in reference to autono mous ventilation system 200 For example controller 220 may set the rate of exhaust fan 210 to an appropriate rate when any IR sensor 214 detects a change in the level of energy of any piece of cooking equipment 114 under exhaust hood 116 Controller 220 may set the speed of exhaust fan 210 to the default idle rate when it is determined via IR sensors 214 that any piece of cooking equipment 114 under exhaust hood 116 has been activated Conversely controller 220 may decrease the speed or completely turn off exhaust fan 210 when it is determined via IR sensors 214 that some or all of cooking equipment 114 has been turned off In addition controller 220 of autonomous ventilation system 300 may set the speed of exhaust fan 210 to a predetermined cooking rate based on the IR index in all or part of cooking zones 216 as determined by IR sensors 214 In this situation controller 220 first deter mines the appropriate rate for each individual piece of cook ing equipment 114 Such rates include for example the nor mal cooking rate and the flare up rate as described above in reference to autonomous ventilation system 200 Controller 220 then sets the speed of exhaust fan 210 to the sum of the required rates of each of the pieces of cooking equipment 114 under exhaust hood 116 or any other suitable speed including one b
5. 932 2 4 497 242 A 2 1985 Moyer se 454 61 6 549 554 B2 4 2003 Shiojima et al 4 556 046 A 12 1985 Riffel 6 645 066 B2 11 2003 Gutta et al 4 584 929 A 4 1986 Jarmyr et al 6 669 547 B2 12 2003 Liu 4 586 486 A 5 1986 Kaufman 6 752 144 BI 6 2004 Lee 4 617 909 A 10 1986 Molitor 6 782 294 B2 8 2004 Reich et al 4 655 194 A 4 1987 Wooden 6 846 236 B2 1 2005 Gregoricka 4 706 553 A 11 1987 Sharp et al 6 851 421 B2 2 2005 Livchak et al 4 773 311 A 9 1988 Sharp 6 869 468 B2 3 2005 Gibson 4 781 460 A 11 1988 Bott 6 878 195 B2 4 2005 Gibson 4 788 905 A 12 1988 Von Kohorn 6 890 252 B2 5 2005 Liu 4 793 715 A 12 1988 Kasner et al ss 374 6 6 899 095 B2 5 2005 Livchak 4 811 724 A 3 1989 Aalto 6 916 239 B2 7 2005 Siddaramanna et al 4 823 015 A 4 1989 Galvin et al 250 564 6 920 874 B1 7 2005 Siegel 4 831 747 A 5 1989 Roos etal cece 34 565 6 974 380 B2 12 2005 Cui et al 4 856 419 A 8 1989 Imai 7 048 199 B2 5 2006 Melink 4 872 892 A 10 1989 Vartiainen et al 7 147 168 B1 12 2006 Bagwell et al 4 903 685 A 2 1990 Melink 7 258 280 B2 8 2007 Wolfson 4 903 894 A 2 1990 Pellinen et al 7 318 771 B2 1 2008 Huang 4 921 509 A 5 1990 Maclin 7 364 004 B2 4 2008 Bagwell et al 4 934 256 A 6 1990 Moss et al 7 442 119 B2 10 2008 Fluhrer 4 944 283 A 7 1990 Tsuchiya 7 699 051 B2 4 2010 Gagasetal 126 299 D 4 944 285 A 7 1990 Glassman 7 866 312 B2 1 2011 Erdmann 126 299 D 5 033 508 A 7 1991 Laverty Jr 137 624 11
6. air contaminant 122 and at a comfortable temperature for anyone inside The volume of air exhausted via exhaust hood 116 should be carefully regu lated 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 contaminant 122 Because a particular piece of cooking equipment 114 may not be in use at all times and thus will not continuously generate air con taminant 122 it becomes beneficial to vary the rate at which exhaust hood 116 ventilates air contaminant 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 dis cussed below provide a convenient alternative to manually activating a ventilation system as the level of air contaminants fluctuates 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 disclo sure are described in reference to kitchen 102 but could be utilized in any facility requiring ventilation FIG 2 depicts an autonomous ventilation system 200 as would be located inside kitchen 102 in accorda
7. 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 fre quency 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 0 40 45 55 6 With reference now to FIG 3 an additional embodiment of an autonomous ventilation system is provided In this embodiment an autonomous ventilation system 300 is oper able to ventilate air contaminant 122 produced from more than one piece of cooking equipment 114 Autonomous ven tilation system 300 comprises the same components described above in reference to autonomous ventilation sys tem 200 but with minor modifications In this embodiment more than one IR sensor 214 and more than one piece of cooking equipment 114 are coupled to controller 220 Each IR sensor 214 can detect IR index fluctuations in or about a corresponding cooking zone 216 beneath exhaust hood 116 Exhausthood 116 is positioned above the more thanone piece ofcooking equipment 114 and directs air contaminants 122 to ceiling exhaust vent 124 Inoperation controller 220 of autonomous ventilation sys tem 300 adjusts the speed of exhaust fan
8. french fries being placed into a fryer s a result of detecting such an event and setting the speed of exhaust fan 210 to a predetermined normal cooking rate autonomous ventilation system 200 will be operational and will ventilate any airborne contaminant 122 that may result in the ensuing cooking session Controller 220 may additionally or alternatively set the speed of exhaust fan 210 to a predetermined flare up rate when IR sensor 214 detects a change in IR index in cooking zone 216 due to a flare up in cooking Such changes in IR index may include a decrease due to the presence of excessive amounts of air contaminant 122 such as smoke or vapor or it may be an increase due to the presence of excessive heat and or flames Conversely controller 220 may decrease the speed or completely turn off exhaust fan 210 after a predeter mined amount of cooking time or when IR sensor 214 detects an IR index corresponding to a low non cooking or non flare up condition This will additionally increase the energy efficiency and comfort level of the kitchen while minimizing unneeded noise The idle cooking and flare up rates of exhaust fan 210 may be determined in a variety of ways For example these rates may be preset and or preprogrammed into controller 220 based on the type of cooking equipment and or the type of food being cooked under exhaust hood 116 user may also determine and or adjust these rates heuristically by observing the operation o
9. laser 428 as described above Once aligned with fixed aperture 418 thermopile sensor 432 will have the same field of view 434 as FOV indicator 430 Since thermopile sensor 432 does not emit visible light the user would not be able to discern the field of view of thermopile sensor 432 without first utilizing FOV indicator 430 By utilizing both instruments the user is able to finely tune the US 8 795 040 B2 9 shape of field of view 434 and precisely select the area in which to monitor IR index fluctuations with thermopile sen sor 432 Modifications additions or omissions may be made to IR sensor assembly 400 and the described components As an example IR sensor assembly 400 may be designed to allow one or more of alignment laser 428 FOV indicator 430 and thermopile sensor 432 to be utilized at the same time In such an embodiment for example a user may elect to illuminate field of view 434 with FOV indicator 430 while thermopile sensor 432 is monitoring IR index fluctuations in field of view 434 Other embodiments of IR sensor assembly 400 may not include alignment laser 428 or FOV indicator 430 Addition ally while certain embodiments have been described in detail numerous changes substitutions variations alter ations and modifications may be ascertained by those skilled in the art and it is intended that the present disclosure encom pass all such changes substitutions variations alterations and modifications as falli
10. radiation IR sensor coupled to the controller sensing an IR index change in a zone below the exhaust hood using the IR sensor and adjusting the speed of the variable speed exhaust fan using the controller based on the IR index change sensed by the IR sensor in the zone below the exhaust fan said IR sensor operating in a sensor assembly the method further including using the sensor assembly aligning an alignment laser to visibly indicate a point at which the sensor assembly is aimed using a field of view indicator visibly illuminating an area where the IR sensor is operable to detect the change in IR index supporting the IR sensor the alignment laser and the FOV indicator using a rotating turret and using one or more adiustable shunts of an aperture assembly adjusting the size of the area where the IR sensor is operable to detect the change in IR index by changing a size and or shape of an aperture of the sensor assembly the sensing an IR index change being such that the IR sensor has a field of view defined by the aperture and using the FOV indicator visually indicating the IR sensor field of view in said area while aligning the FOV indi cator with the aperture the sensing an IR index change the aligning an alignment laser and the visually indicating employing the rotating turret and the aperture such that only one of the IR sensor the alignment laser and the FOV indicator is aligned with said aperture at a
11. under 35 U S C 119 e of U S Provisional Application No 60 968 395 filed Aug 28 2007 entitled Smart Kitchen Ventilation Hood with Thermopile Sensor The entire content of each of the foregoing applications is hereby incorporated by reference into the present application TECHNICAL FIELD This disclosure relates in general to control systems and more particularly to an autonomous ventilation system BACKGROUND Ventilation systems are commonly found in modern resi dential 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 com fort of those present in the kitchen and adjacent areas Venti lation 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 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 usu ally 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 smo
12. 34 has been adjusted to match the area in which IR index fluctuations are to be monitored the user may then rotate rotating turret 410 in order to use alignment laser 428 and or thermopile sensor 432 For example the user may rotate rotating turret 410 to align alignment laser 428 with fixed aperture 418 Alignment laser 428 may be any type of visible laser including a visible light laser diode Once activated alignment laser 428 will produce a point of light on any object in its line of sight If IR sensor assembly 400 is aimed at a piece of equipment that is movable this point of light produced by alignment laser 428 may be used to realign the piece of equipment back to the same position each time after it is moved To do this the user marks on the piece of equipment the location of the point of light produced by alignment laser 428 when it is in the desired position After moving the user would then reposition the piece of equip ment so that the mark aligns with the point of light produced by alignment laser 428 This allows the piece of equipment to be easily realigned to the same position every time and pre vents the user from having to continuously readjust field of view 434 In addition once field of view 434 has been adjusted to match the area in which IR index fluctuations are to be moni tored the user may rotate rotating turret 410 to align thermo pile sensor 432 with fixed aperture 418 this may be done regardless of the use of
13. 6 Wall 106 contains a door way 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 sup ply 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 oper able to direct an air contaminant 122 associated with the US 8 795 040 B2 3 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 condi tioned 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 Removing air contaminant 122 from kitchen 102 helps ensure that kitchen 102 as well as adjacent room 104 remains safe sufficiently free of
14. 9 A 9 1978 Ookubo 5 720 274 A 2 1998 Brunner et al 4 117 833 A 10 1978 Mueller 5 764 579 A 6 1998 McMasters et al 4 127 106 A 11 1978 Jensen 5 779 538 A 7 1998 Jardinier 4 134 394 A 1 1979 Otenbaker 5 874 292 A 2 1999 McMinn Jr 4 138 220 A 2 1979 Davies 5 882 254 A 3 1999 Jacob 454 61 4 146 017 A 3 1979 Overton 5 960 786 A 10 1999 Lambertson 4 147 502 A 4 1979 Milton 5 992 152 A 11 1999 Weres et al 4 153 044 A 5 1979 Nett 6 044 838 A 4 2000 Deng 4 155 348 A 5 1979 Ahlrich 6 058 929 A 5 2000 Fritz 4 160 407 A 7 1979 Duym 6 089 970 A 7 2000 Feustel 4211 154 A 7 1980 Eakes 6 154 686 A 11 2000 Hefferen et al 700 276 4213 947 A 7 1980 Fremont 6 170 480 B1 1 2001 Melink et al 126 299 R 4 285 390 A 8 1981 Fortune et al 6 171 480 BL 1 2001 Lee etal 4 286 572 A 9 1981 Searcy 6 173 710 Bl 1 2001 Gibson et al 4 287 405 A 9 1981 Ohmae et al 6 179 763 B1 1 2001 Phillips III 4 346 692 A 8 1982 Mccauley 6 252 689 B1 6 2001 Sharp 4 350 166 A 9 1982 Mobarry occ 600 473 6 336 451 BI 1 2002 Rohl Hager et al 4 373 507 A 2 1983 Schwartz 6 347 626 BI 2 2002 Yi 4 398 415 A 8 1983 Jacocks et al 6 351 999 B1 3 2002 Maul et al 4 467 782 A 8 1984 Russel 6 428 408 Bl 8 2002 Bell et al 4 475 534 A 10 1984 Moriarty 6 450 879 BI 9 2002 Suen 4 483 316 A 11 1984 Fritz 6 515 283 B1 2 2003 Castleman et al 250 339 15 4 484 563 A 11 1984 Fritz et al 6 531 966 B2 3 2003 Krieger 340
15. 95 040 B2 450 U S Patent Aug 5 2014 Sheet 7 of 8 US 8 795 040 B2 500 age DETERMINE THE ENERGY LEVEL OF COOKING EQUIPMENT BELOW THE EXHAUST HOOD 504 IS THE ENERGY LEVEL GREATER THAN NOMINAL ENSURE SET FAN SPEED TO OFF ADJUST THE EXHAUST FAN SPEED TO A 508 PREDETERMINED IDLE RATE OR AN IDLE RATE BASED ON THE IR RADIATION INDEX OF THE COOKING EQUIPMENT MONITOR WITH IR SENSOR THE IR RADIATION INDEX IN A ZONE BELOW THE EXHAUST HOOD 512 HAS THE IR RADIATION INDEX DROPPED INDICATING A PRESENCE OF UNCOOKED FOOD 514 YES TO FIG 6B FROM FIG 6B FIG 6A U S Patent Aug 5 2014 Sheet 8 of 8 US 8 795 040 B2 FROM FIG 6A TO FIG 6A 516 ADJUST THE EXHAUST FAN SPEED TO A RATE CORRESPONDING TO NORMAL COOKING CONDITIONS 518 START A TIMER MEASURE WITH IR SENSOR THE IR RADIATION INDEX OF OBJECTS IN A ZONE BELOW THE EXHAUST HOOD HAS THE IR RADIATION INDEX CHANGED INDICATING A FLARE UP IS PRESENT 524 ADJUST THE EXHAUST FAN SPEED TO A RATE CORRESPONDING TO FLARE UP COOKING CONDITIONS HAS THE TIMER EXPIRED 526 YES SET THE EXHAUST FAN 528 SPEED BACK TO IDLE RATE FIG 6B US 8 795 040 B2 1 AUTONOMOUS VENTILATION SYSTEM CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation of Application No 11 947 924 filed Nov 30 2007 This application also claims the benefit
16. AC system 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 enu merated above various embodiments may include all some or none of the enumerated advantages BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding of the present disclo sure and its advantages reference is now made to the follow ing description taken in conjunction with the accompanying drawings in which FIG 1 is a simplified block diagram illustrating a facility requiring ventilation in accordance with a particular embodi ment FIG 2 is a simplified block diagram illustrating a ventila tion system in accordance with a particular embodiment FIG 3 is a simplified block diagram illustrating a ventila tion system in accordance with another particular embodi ment FIG 4A 4C is an exploded view of an IR sensor assembly in accordance with a particular embodiment FIG 5 is an exploded view of an IR sensor assembly in accordance with a another particular embodiment and FIG 6 is a method of controlling a ventilation system in accordance with a particular embodiment DETAILED DESCRIPTION OF THE DISCLOSURE FIG 1 depicts a facility 100 where a particular embodi ment 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 10
17. US008795040B2 a2 United States Patent 10 Patent No US 8 795 040 B2 Burdett et al 45 Date of Patent Aug 5 2014 54 AUTONOMOUS VENTILATION SYSTEM 2 853 367 A 9 1958 Karol 2 862 095 A 11 1958 Scofield 75 Inventors Michael P Burdett Tucson AZ US 2 933 080 A 4 1960 Adey 3 045 705 A 7 1962 Hausammann Daniel Reich Tucson AZ US 4 Continue 73 Assignee Oy Halton Group Ltd Helsinki FI FOREIGN PATENT DOCUMENTS Notice Subject to any disclaimer the term of this AU 1138776 9 1977 patent is extended or adjusted under 35 U S C 154 b by 163 days AU 340069 MER Continued 21 Appl No 13 187 762 OTHER PUBLICATIONS 22 Filed Jul 21 2011 International Search Report and Written Opinion dated Jan 5 2007 rf for International Application No PCT US05 26378 filed Jul 25 65 Prior Publication Data 2005 US 2011 0275301 A1 Nov 10 2011 Continued Related U S Application Data Primary Examiner Steven B McAllister 63 Continuation of application No 11 947 924 filed on Assistant Examiner Frances H Kamps Nov 30 2001 ow aband ned 74 Attorney Agent or Firm Miles amp Stockbridge P C 60 Provisional application No 60 968 395 filed on Aug 28 2007 57 ABSTRACT An autonomous ventilation system includes a variable speed GD 2S 5 02 2006 01 exhaust fan a controller an exhaust hood and an infrared F24C 15 20 200 6 01 radiation IR sensor Th
18. Walsh 3 323 439 A 6 1967 Waever et al 5 146 284 A 9 1992 Tabarelli et al 3 332 676 A 7 1967 Namy 5 205 783 A 4 1993 Dieckert et al 3 381 134 A 4 1968 Wolf 5 215 075 A 6 1993 Caridis 3 400 649 A 9 1968 Jensen 5 215 497 A 6 1993 Drees 3 457 850 A 7 1969 Sweet et al 5 220 910 A 6 1993 Aalto 3 513 766 A 5 1970 Alhrich 5 240 455 A 8 1993 Sharp 3 536457 A 10 1970 Henderson 5 251 608 A 10 1993 Cote 3 612 106 A 10 1971 Camboulives et al 5 268 739 A 12 1993 Martinelli et al 3 690 245 A 9 1972 Ferlise et al 5 311 930 A 5 1994 Bruenn 3 752 056 A 8 1973 Chamberlin et al 5 312 296 A 5 1994 Aalto 3 809 480 A 5 1974 Somerville et al 5 312 297 A 5 1994 Dieckert et al 3 825 346 A 7 1974 Rizzo 5 394 861 A 3 1995 Stegmaier 3 829 285 A 8 1974 Beck 5 406 073 A 4 1995 Sharp et al 250 221 3 866 055 A 2 1975 Pike 5 414 509 A 5 1995 Veligdan 3 895 569 A 7 1975 Miller 5 415 583 A 5 1995 Brandt Jr 3 943 836 A 3 1976 Kuechler 5 518 446 A 5 1996 Jacob 3 952 640 A 4 1976 Kuechler 5 522 377 A 6 1996 Fritz 3 978 777 A 9 1976 Nett 5 558 821 A 9 1996 Konig 4 043 319 A 8 1977 Jensen 5 580 535 A 12 1996 Hoke 4 047 519 A 9 1977 Nett 5 597 354 A 1 1997 Janu et al 4 050 368 A 9 1977 Eakes 5 622 100 A 4 1997 King 4 056 877 A 111977 Kuechler 5 657 744 A 8 1997 Vianen 4 085 736 A 4 1978 Kuechler 5 713 346 A 2 1998 Kuechler 4 105 015 A 8 1978 Isom 5 716 268 A 2 1998 Strongin 4 109 641 A 8 1978 Hunzicker 5 718 219 A 2 1998 Boudreault 4 113 43
19. an IR sensor assembly 400 which could be utilized as IR sensor 214 discussed above in connection with FIGS 2 and 3 FIG 4A provides a top view of IR sensor assembly 400 FIG 4B provides a bottom view of IR sensor assembly 400 and FIG 4C provides a side view of IR sensor assembly 400 IR sensor assembly 400 includes a housing 402 a ball joint 404 a ball joint bracket 406 anda mounting bracket 408 Ball joint 404 is coupled to mounting bracket 408 and housing 402 is coupled to ball joint bracket 406 Ball joint 404 fits inside ball joint bracket 406 and allows coupled housing 402 to rotate freely about ball joint 404 Housing 402 includes a rotating turret 410 aperture shunts 412 an axle pin 414 aperture set screws 416 a fixed aperture 418 and an adjustable aperture 420 Fixed aperture 418 is located on one side of housing 402 and allows light and infrared radiation to pass in and out of housing 402 Aperture shunts 412 are affixed adjacent to fixed aperture 418 with aperture set screws 416 Aperture set screws 416 may be manually adjusted in a way that allows aperture shunts 412 to slide and block a portion none or all of the light that exits housing 402 via fixed aperture 418 The ends of aperture shunts 412 form adjustable aperture 420 whose shape may be manipulated by adjusting the position of one or more aperture shunts 412 Aperture shunts 412 may be black or otherwise dark in color to reduce disturbances in the light emitted fr
20. ased on the size and shape of exhaust hood 116 or the type of cooking equipment 114 Controller 220 may con versely decrease the speed or completely turn off exhaust fan 210 after a predetermined amount of cooking time or when IR sensors 214 detect an IR index corresponding to a low non cooking or non flare up condition under exhaust hood 116 Modifications additions or omissions may be made to autonomous ventilation system 300 and the described com ponents As an example while FIG 3 depicts two pieces of cooking equipment 114 two IR sensors 214 and two cooking zones 216 autonomous ventilation system 300 may be modi fied to include any number and combination of these items Additionally while certain embodiments have been described in detail numerous changes substitutions varia tions alterations and modifications may be ascertained by those skilled in the art For example while autonomous ven tilation systems 200 and 300 have been described in reference to kitchen 102 and cooking equipment 114 certain embodi ments 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 modifica tions as falling within the spirit and scope of the appended claims US 8 795 040 B2 7 FIGS 4A through 4C depict
21. deling of a Swirling Coal Flame DE 4203916 4 1993 Combustion Science and Technology 1997 123 pp 1 22 DE 19613513 10 1997 Morsi et al An Investigation of Particle Trajectories in Two Phase EP 03 14085 5 1989 Flow Systems Journal of Fluid Mechanics 1972 55 pp 193 208 EP 0401583 12 1990 Abstract for Tennekes et al A First Course of Turbulence Mass EP 0541862 5 1993 Inst Tech 1972 EP 0541863 5 1993 Prosecution history of U S Appl No 07 010 277 now U S Patent EP 0623398 11 1994 No 4 811 724 E 0227032 Brees Non Final Office Action dated May 28 2010 in U S Appl No EP 1250556 10 2002 1240 5686 EP 1637810 3 2006 Translation of foreign patent document DE 4203916 EP 1778418 2 2007 Skimm G K Technician s Guide to HVAC 1995 McGraw Hill pp FI 58971 1 1981 322 330 FR 2008451 1 1970 FR 2301778 9 1976 cited by examiner U S Patent Aug 5 2014 Sheet 1 of 8 US 8 795 040 B2 4 f 3 I U f FIG I U S Patent Aug 5 2014 Sheet 2 of 8 US 8 795 040 B2 200 110 FIG 2 P US 8 795 040 B2 Sheet 3 of 8 Aug 5 2014 U S Patent 300 110 U S Patent Aug 5 2014 Sheet 4 of 8 US 8 795 040 B2 400 FIG 4A 400 U S Patent Aug 5 2014 Sheet 5 of 8 US 8 795 040 B2 SSS SSS r Q AE ER 400 408 402 406 e 404 414 449 492 toS d pecu EE E E We TS 420 412 416 416 U S Patent Aug 5 2014 Sheet 6 of 8 US 8 7
22. diments the shape of aperture 466 is adjustable by a user similar to how the airflow of an eyeball air vent is adjusted on many commercial airlines Laser calibration assembly 454 includes a housing 470 an activation button 472 a spring switch 474 coin cell batteries 476 and a diode laser 478 Housing 470 contains an opening at each end Diode laser 478 is enclosed inside housing 470 in such a way as to allow it to shine a visible calibration beam 480 through the opening of one end of housing 470 Activa tion button 472 is also enclosed inside housing 470 and par tially protrudes out of the opening in housing 470 opposite from calibration beam 480 Activation button 472 is in the shape of aperture 466 on ball housing 464 and is slightly smaller to allow it to easily slide into and out of aperture 466 For example activation button 472 may be cylindrical in shape to allow it to fit into an aperture 466 that is round as seen in FIG 5 Activation button 472 is also slightly smaller than the opening of housing 470 from which it protrudes This allows it to move in and out of housing 470 through the opening lip adjacent to one end of activation button 472 however prevents the button from sliding completely out of housing 470 25 35 40 45 50 10 One or more coin cell batteries 476 are positioned adjacent to diode laser 478 inside housing 470 Enough coin cell batteries 476 are provided to power diode laser 478 causing it t
23. e exhaust fan removes air contami G01J 5 48 200 6 01 nants from an area The controller is coupled to the exhaust fan and adjusts the speed of the exhaust fan The exhaust hood 52 U S Cl is coupled to the exhaust fan and directs air contaminants to USPC meet 454 61 454 56 454 58 454 67 the exhaust fan The IR sensor is coupled to the controller 250 334 detects changes in IR index ina zone below the exhaust hood 58 Field of Classification Search and communicates information relating to detected changes USPC 454 61 56 58 67 250 330 332 334 in IR index to the controller The controller adjusts the speed MC 250 338 1 342 of the exhaust fan in response to information relating to See application file for complete search history detected changes in IR index The autonomous ventilation system also includes an alignment laser to indicate a point at 56 References Cited which the IR sensor is aimed and a field of view FOV U S PATENT DOCUMENTS indicator to illuminate the zone in which the IR sensor detects changes in IR index 2 743 529 A 5 1956 Hayes 2 833 615 A 5 1958 Kollgaard 10 Claims 8 Drawing Sheets 402 406 404 414 410 92 424 y 2 2 432 426 416 US 8 795 040 B2 Page 2 56 References Cited 5 090 303 A 2 1992 Ahmed 5 092 227 A 3 1992 Ahmed et al U S PATENT DOCUMENTS 5 115 728 A 5 1992 Ahmed et al 5 139 009 A 8 1992
24. ep 516 In particular embodiments the speed may be adjusted based on the amount of the drop in IR index determined in step 514 After adjusting the speed of exhaust fan 210 to a predeter mined normal cooking level autonomous ventilation control method 500 may next proceed to start a timer in step 518 The length of the timer in step 518 determines how long exhaust fan 210 remains at the cooking rate The length of the timer may be based on the amount of IR index drop caused by the introduction of food into cooking zone 216 The larger the drop in IR index measured in step 512 the more uncooked or cold food has been introduced into cooking zone 216 The length of the timer set in step 518 may also be a fixed amount of time corresponding to the type of cooking equipment and or food being cooked or it may be an amount of time pro grammed by a user Note that in some embodiments a timer my not be used at all to determine how long exhaust fan 210 remains at the cooking rate In such an embodiment IR sensor 214 may be used to determine when cooking is complete and set exhaust fan 210 back to the idle rate After setting the timer in step 518 autonomous ventilation control method 500 may next proceed to monitor cooking zone 216 for flare ups A flare up condition occurs when excessive amounts of air contaminants 122 such as steam smoke or heat are produced by cooking with cooking equip ment 114 To determine if a flare up exists the IR index o
25. f cooking zone 216 is measured with IR sensor 214 in step 520 In step 522 the IR index is analyzed to determine if a change in IR index has occurred due to the presence of excessive 0 an 5 20 40 45 50 55 60 65 12 amounts of air contaminants 122 The change in IR index may include a decrease associated with excessive amounts of smoke steam or vapor or it may be an increase associated with excessive amounts of heat from flames If a flare up condition exists the speed of exhaust fan 210 is increased from the normal cooking rate to a predetermined flare up rate If no flare up condition exists the speed of the exhaust fan 210 is maintained at the normal cooking rate Next autonomous ventilation control method 500 pro ceeds to determine in step 526 if the timer set in step 518 has expired If the timer has expired the speed of exhaust fan 210 is decreased to the idle rate in step 528 and autonomous ventilation control method 500 proceeds back to step 504 to monitor the energy level of cooking equipment 114 If the timer has not expired autonomous ventilation control method 500 proceeds back to step 520 to monitor for flare up condi tions Alternatively if a timer is not used in a particular embodiment IR sensor 214 may be used in step 526 to deter mine when cooking is complete and proceed to the next step While a particular autonomous ventilation control method has been described it should be noted
26. f autonomous ventilation system 200 in the environment in which it is installed Pre determined times for particular cooking equipment could also be provided from a manufacturer or standards body It should also be noted that even though three distinct rates have been identified it is intended that the present disclosure encompass other rates as well For example controller 220 may gradually increase the rate of exhaust fan 210 over time from a lower rate such as the idle rate to a higher rate such as the cooking rate Likewise it may gradually decrease the rate of exhaust fan 210 over time from a higher rate such as the flare up rate to a lower rate such as the cooking rate In some embodiments controller 220 may also automati cally 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 This ensures that the environment in kitchen 102 remains safe and comfortable regardless of how much air is being ventilated through exhaust hood 116 Exhaust fan 210 and supply air fan 212 may be powered
27. ing 402 about ball joint 404 This allows three dimensional adjustments to aim IR sensor assembly 400 at the desired location To select one of the attached instruments including alignment laser 428 FOV indicator 430 and thermopile sensor 432 the user grasps rotation handle 422 and rotates rotating turret 410 about axle pin 414 until the desired instrument is aligned with fixed aperture 418 This allows the selected instrument to have a clear line of sight out of housing 402 To ensure IR sensor assembly 400 is aimed at the correct location to be monitored for IR index fluctuations the user would first rotate rotating turret 410 to select FOV indicator 430 FOV indicator 430 may be any visible light emitting device including but not limited to a bright light LED Once FOV indicator 430 is selected and activated it will shine light out of housing 402 via fixed aperture 418 The result will be 0 20 25 30 35 40 45 50 55 60 65 8 a field of view 434 which is a pattern of light on an object in the line of sight of FOV indicator 430 in the shape of fixed aperture 418 This corresponds with the field of view of thermopile sensor 432 when such sensor is rotated into posi tion in line with aperture 418 420 Initially adjustable aperture 420 is larger in size than fixed aperture 418 and thus the shape of field of view 434 is con trolled by fixed aperture 418 However adjustable aperture 420 may be adjusted to
28. ke 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 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 opera tion 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 The present disclosure provides an autonomous ventilation system that substantially eliminates or reduces at least some of the disadvantages a
29. l 8 2007 Fluhrer JP 2000 081216 3 2000 2007 0202791 Al 8 2007 Lee JP 2002 089859 3 2002 2007 0229293 AL 10 2007 Martino aaa 340 630 JP 2003 519771 6 2003 2007 0272230 A9 11 2007 Meredith et al JP 2003 269770 9 2003 2008 0045132 Al 2 2008 Livchak et al NL 7601862 2 1976 2008 0138750 Al 6 2008 Kim mme 431 12 SE 7602168 8 1976 2008 0141996 Al 6 2008 Erdmann SE 7904443 11 1980 2008 0207109 Al 8 2008 Bagwell WO 86 06 154 10 1986 2008 0258063 Al 10 2008 Rapanotti 250 334 WO 91 17803 11 1991 2008 0297808 Al 12 2008 Riza etal o 356 503 WO 92 08082 5 1992 2008 0302247 Al 12 2008 Magner SO pf E rdi 2008 0308088 Al 12 2008 Livchak NO 0109125 115001 2009 0032011 Al 2 2009 Livchak etal 126 299 D WO 01 84054 io 2009 0093210 Al 4 2009 Livchak WO 02 14728 2 2002 2009 0199844 Al 8 2009 Meredith WO 02 14746 2 2002 WO 2005 019736 3 2005 FOREIGN PATENT DOCUMENTS WO 2005 114059 12 2005 WO 2006 002190 1 2006 AU 2933601 7 2001 WO 2006 012628 2 2006 BE 838829 6 1976 WO 2006 074420 7 2006 CA 1054430 5 1979 WO 2006 074425 7 2006 CA 1069749 1 1980 WO 2007 121461 10 2007 CA 1081030 7 1980 WO 2008 157418 12 2008 CA 2536332 3 2005 WO 2009 092077 7 2009 CH 682512 9 1993 WO 2009 129539 10 2009 BE Am r OTHER PUBLICATIONS BE Ses de Abstract for Gidaspow D Multiphase Flow and Fluidization Con DE 4120175 2 1992 tinuum and Kinetic Theory Descriptions Academic Press 1994 DE 4114329 11 1992 Saravelou et al Detailed Mo
30. le to visibly illuminate an area where the IR sensor is operable to detect the change in IR index a rotating turret supporting the IR sensor the alignment laser and the FOV indicator and an aperture assembly having one or more adjustable shunts operable to adjust the size of the area where the IR sensor is operable to detect the change in IR index by changing a size and or shape of an aperture of the sensor assembly the rotating turret and the aperture are constructed such that only one of the IR sensor the alignment laser and the FOV indicator is aligned with said aperture at a time the IR sensor has a field of view defined by the aperture when the IR sensor is aligned with the aperture and US 8 795 040 B2 13 the FOV indicator provides a visual indication of the IR sensor field of view in said area when the FOV indicator is aligned with the aperture 2 The system of claim 1 wherein the IR sensor is a ther mopile sensor 3 The system of claim 1 further comprising a variable speed supply fan that is configured to deliver supply air to said area wherein the controller is further configured to adjust the speed of the supply fan based on a speed of the exhaust fan 4 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 is operable to remove an air contami nant from an area providing an infrared
31. mbly is aimed a field of view FOV indicator operable to visibly illu minate an area where the IR sensor is operable to detect the change in IR index a rotating turret supporting the IR sensor the alignment laser and the FOV indicator an aperture assembly having one or more adjustable shunts operable to adjust the size of the area where the IR sensor is operable to detect the change in IR index by changing asize and or shape of an aperture of the sensor assembly wherein the rotating turret and the aperture are constructed such that only one of the IR sensor the alignment laser and the FOV indicator is aligned with said aperture at a time the IR sensor field of view is defined by the aperture when the IR sensor is aligned with the aperture and the FOV indicator provides a visual indication of the IR sensor field of view in said area when the FOV indicator is aligned with the aperture
32. nce 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 equip ment 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 uncondi tioned 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 Autonomous ventilation system 200 also includes an IR sen sor 214 that can detect IR index the heat signature given off by an object fluctuations in or about a cooking zone 216 associated with cooking equipment 114 beneath exhaust hood 116 According to a particular embodiment IR sensor 214 is a thermopile sensor for remotely sensing infrared radiation changes in cooking zone 216 IR sensor 214 how ever may be any type of IR sensor and is not limited in scope to a thermopile sensor IR sensor 214 may be mounted inside exhaust hood 116 on top of exhaust hood 116 on a ceiling 218
33. nd problems associated with previous methods and systems 20 25 30 35 40 45 50 55 60 65 2 According to one embodiment an autonomous ventilation system includes a variable speed exhaust fan a controller an exhaust hood and an infrared radiation IR sensor The exhaust fan removes air contaminants from an area The con troller 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 IR sensor is coupled to the controller detects changes in IR index in a zone below the exhaust hood and communicates infor mation relating to detected changes in IR index to the con troller The controller adjusts the speed of the exhaust fan in response to information relating to changes in IR index detected by the IR sensor Other embodiments also include an alignment laser to visibly indicate a point at which the IR sensor is aimed and a field of view FOV indicator to illuminate the zone below the exhaust hood in which the IR sensor detects changes in IR index Technical advantages of certain embodiments may include areduction in energy consumption an increase in the comfort of the ventilated area and a decrease in noise Embodiments may eliminate certain inefficiencies such as needlessly ven tilating valuable air from an area that was supplied by a heating ventilation and air conditioning HV
34. ng within the spirit and scope of the appended claims FIG 5 depicts an IR sensor assembly 450 which could be also be utilized as IR sensor 214 discussed above in connec tion with FIGS 2 and 3 IR sensor assembly 450 includes an eyeball housing assembly 452 and a laser calibration assem bly 454 Eyeball housing assembly 452 includes a retaining bracket 456 a position fixing o ring 458 and a ball housing 464 Retaining bracket 456 contains mounting holes 462 that allow it to be attached with fasteners such as screws to any surface Retaining bracket 456 also contains a round void that is large enough to allow ball housing 464 to partially fit through Position fixing o ring 458 is attached to retaining bracket 456 about the circumference of the round void and makes contact with ball housing 464 when it is placed into the round void Retaining bracket 456 and position fixing o ring 458 together form a socket in which ball housing 464 pivots Ball housing 464 contains an aperture 466 and an IR sensor 460 IR sensor 460 is affixed to ball housing 464 on the opposite side of aperture 466 in such a way that allows it to have a line of sight through ball housing 464 and out aperture 466 IR sensor 460 receives an IR field 468 through ball housing 464 and aperture 466 IR sensor 460 detects IR index fluctuations inside IR field 468 IR field 468 is in the shape of aperture 466 which may be any shape including round as shown in FIG 5 In some embo
35. o produce visible calibration beam 480 Coin cell batteries 476 are positioned inside housing 470 so that only one termi nal positive or negative of coin cell batteries 476 is coupled to diode laser 478 Spring switch 474 is positioned inside housing 470 between the other uncoupled terminal of coin cell batteries 476 and activation button 472 It is coupled to diode laser 478 on one end and activation button 472 on the other small gap of air exists between spring switch 474 and the uncoupled terminal of coin cell batteries 476 when laser calibration assembly is inactive so that the electrical circuit between coin cell batteries 476 and diode laser 478 is not complete In operation eyeball housing assembly 452 is mounted with retaining bracket 456 in a location where it has a clear line of sight to an area to be monitored for IR index fluctua tions Once mounted in a desired location eyeball housing assembly 452 may be adjusted by pivoting ball housing 464 This allows three dimensional adjustments to aim IR sensor 460 at the desired location This is similar in operation to an eyeball air vent that is typical in most commercial airlines Ball housing 464 pivots about the void in retaining bracket 456 and maintains its position after adjustments due to the pressure applied by position fixing o ring 458 Because IR sensor 460 produces IR field 468 that is invis ible to the human eye it is difficult to reliably determine exactly where IR
36. om adjustable aperture 420 Rotating turret 410 includes a rotation handle 422 a reten tion spring 424 a retention bearing 426 an alignment laser 428 a field of view FOV indicator 430 and a thermopile sensor 432 Rotation handle 422 is affixed to rotating turret 410 and rotating turret 410 is affixed to housing 402 via axle pin 414 Rotating turret 410 is operable to rotate about axle pin 414 by grasping and applying force to rotation handle 422 Retention spring 424 is affixed to rotating turret 410 and is subsequently coupled to retention bearing 426 Retention spring 424 applies pressure to retention bearing 426 that is in contact with housing 402 This pressure creates resistance to the movement of rotating turret 410 and thus ensures rotating turret 410 does not rotate without sufficient force by the user Alignment laser 428 FOV indicator 430 and thermopile sensor 432 are affixed to rotating turret 410 in such a way that each may be aligned with fixed aperture 418 When rotating turret 410 is rotated into the appropriate position alignment laser 428 FOV indicator 430 and thermopile sensor 432 may each have a clear line of sight out of housing 402 via fixed aperture 418 In operation IR sensor assembly 400 is mounted with mounting bracket 408 in a location where it has a clear line of sight to an area to be monitored for IR index fluctuations Once mounted in a desired location housing 402 may be adjusted by pivoting hous
37. overlap fixed aperture 418 in order to adjust the shape of field of view 434 The shape of adjustable aperture 420 and field of view 434 may be adjusted via aper ture shunts 412 so that field of view 434 coincides with the desired area to be monitored for IR index fluctuations In one embodiment IR sensor assembly 400 is utilized as IR sensor 214 in autonomous ventilation system 200 Field of view 434 corresponds to cooking zone 216 and coincides with an area associated with cooking equipment 114 beneath exhaust hood 116 Field of view 434 may envelop any area associated with cooking equipment 114 including an area adjacent to cooking equipment 114 where uncooked food products are loaded for cooking a portion of the surface of cooking equip ment 114 or the entire surface of cooking equipment 114 To adjust the shape of field of view 434 one or more aperture set screws 416 are loosened to allow the associated aperture shunt 412 to slide freely One or more aperture shunts 412 are adjusted so that one end overlaps fixed aperture 418 By overlapping fixed aperture 418 aperture shunts 412 will block light emitted via fixed aperture 418 and thus affect and control the shape of field of view 434 Once aperture shunts 412 are in the desired position and field of view 434 is in the desired shape aperture set screws 416 are then tightened to secure aperture shunts from further movement and set the shape of adjustable aperture 420 Once field of view 4
38. ple if the IR index of the cooking surface or cooking medium of cooking equipment 114 is not greater than the average IR index when not in use i e the energy level is low or zero it is determined that no ventilation is required s a result exhaust fan 210 is turned off if it is not already off and autonomous ventilation control method 500 proceeds back to step 504 If however the IR index of the cooking surface or cooking medium of cooking equipment 114 determined in step 504 is greater than the average IR index when not in use or if the energy level is otherwise determined to be above a particular threshold autonomous ventilation control method 500 proceeds to step 508 where the speed of exhaust fan 210 is a set to an idle rate The idle rate may be for example a predetermined rate or a rate based on the measured IR index Once it is determined in steps 504 and 506 that cooking equipment 114 has been activated autonomous ventilation control method 500 next proceeds to monitor cooking zone 216 In step 512 the IR index of cooking zone 216 is moni tored with IR sensor 214 In step 514 the IR index or changes in IR index of cooking zone 216 is analyzed to determine if uncooked i e cold food has been introduced If it is deter mined in step 514 that a drop in IR index has occurred due to uncooked food being introduced into cooking zone 216 the speed of exhaust fan 210 is adjusted to a predetermined nor mal cooking rate in st
39. sensor assembly 450 is aimed To alleviate this problem a user may utilize laser calibration assembly 454 To do so a user first inserts the end of laser calibration assembly 454 containing activation button 472 into aperture 466 of ball housing 464 Activation button 472 will slide into aperture 466 for a certain distance until it comes into contact with a portion of ball housing 464 or IR sensor 460 that impedes its movement At this point the user continues to apply pressure to IR sensor assembly 450 in the direction of ball housing 464 This will cause housing 470 to then slide toward ball housing 464 while activation button 472 remains immobile This causes the end of activation button 472 inside housing 470 to contact spring switch 474 and in turn causes spring switch 474 to contact the uncoupled terminal of coin cell batteries 476 This completes the electrical circuit between coin cell batteries 476 and diode laser 478 and pro duces visible calibration beam 480 While still grasping laser calibration assembly 454 the user may then adjust IR sensor assembly 450 by pivoting ball housing 464 about retaining bracket 456 Since laser calibration assembly 454 is still inserted into aperture 466 of ball housing 464 when the user makes this adjustment diode laser 478 will be aligned with IR sensor 460 As a result visible calibration beam 480 will be produced that is aligned with invisible IR field 468 The user may then adjust IR sensor assembl
40. t 114 autonomous ventilation system 200 allevi ates disadvantages of other ventilation systems such as wasted energy and unnecessary noise In some embodiments controller 220 may additionally or alternatively adjust the speed of exhaust fan 210 based on the state of IR sensor 214 In this configuration controller 220 monitors whether sensor 214 has been activated by a user When a user activates IR sensor 214 controller 220 will set the speed of exhaust fan 210 to a predetermined idle rate or a rate based on the IR index measured by IR sensor 214 In addition a user may choose to override IR sensor 214 alto gether By pushing the appropriate override button a user may choose to override IR sensor 214 and manually force controller 220 to increase the speed of exhaust fan 210 This allows the user manual control of autonomous ventilation system 200 when desired In addition or alternatively controller 220 of autonomous ventilation system 200 may set the speed of exhaust fan 210 to a predetermined normal cooking rate when IR sensor 214 US 8 795 040 B2 5 detects a drop in IR index in all or part of cooking zone 216 dueto the introduction of uncooked or cold food As examples only IR sensor 214 may detect a drop in IR index in all or part of cooking zone 216 due to cold and or uncooked food being placed over an active burner cold and or uncooked food such as frozen hamburger patties being placed at the input to a broiler or uncooked
41. that certain steps may be rearranged modified or eliminated where appropriate Additionally while certain embodiments have been described in detail numerous changes substitutions varia tions 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 varia tions alterations and modifications as falling within the spirit and scope of the appended claims What is claimed is 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 an infrared radiation IR sensor coupled to the control ler the IR sensor configured to detect a change in IR index in a zone below the exhaust hood and to commu nicate information relating to detected changes in IR index to the controller wherein the controller is further operable to adjust the speed of the fan in response to information relating to changes in IR index detected by the IR sensor said IR sensor is part of a sensor assembly which also includes an alignment laser operable to visibly indicate a point at which the sensor assembly is aimed a field of view indicator operab
42. time 5 The method of claim 4 wherein the exhaust hood is located above one or more pieces of cooking equipment and 20 25 30 35 40 14 the exhaust fan 1s configured to exhaust contaminants arising from operation of said cooking equipment 6 The method of claim 4 wherein the sensed IR index change is a decrease associated with an introduction ofa food product to the zone below the exhaust hood and the speed of the exhaust fan is adjusted to a predetermined speed for a predetermined period of time associated with cooking of the food product 7 The method of claim 4 wherein the sensed IR index change is a decrease associated with an air contaminant pro duced by a food product being cooked in the zone below the exhaust hood and the speed of the exhaust fan is adjusted to a predetermined speed so as to remove the air contaminant 8 The method of claim 4 further comprising controlling a variable speed supply fan that is configured to deliver supply air from an air supply source to said area and adjusting a speed of the supply fan based on the speed of the exhaust fan 9 The method of claim 8 wherein the adjusted speed of the supply fan is greater than or equal to the speed of the exhaust fan 10 A sensor assembly comprising an infrared radiation IR sensor operable to detect a change in IR index within its field of view an alignment laser operable to visibly indicate a point at which the sensor asse
43. y 450 by pivoting ball housing 464 until visible calibration beam 480 is in the desired position Once in the desired position the user finally removes laser calibration assembly 454 and allows IR field 468 to be received by IR sensor 460 through aperture 466 from the desired target With reference now to FIG 6 an autonomous ventilation control method 500 is provided Autonomous ventilation con trol method 500 may be implemented for example by con troller 220 described in reference to autonomous ventilation systems 200 and 300 in FIGS 2 and 3 above Autonomous ventilation control method 500 will now be described in ref erence to controller 220 as utilized in kitchen 102 It must be US 8 795 040 B2 11 noted however that autonomous ventilation control method 500 may be utilized by any controller to control a ventilation system regardless of location Autonomous ventilation control method 500 begins in step 504 where the energy level of cooking equipment 114 is determined or where the activation of the equipment is oth erwise determined The energy level of cooking equipment 114 may be determined by any suitable technique including utilizing IR sensor 214 to determine the IR index of the cooking surface or cooking medium of cooking equipment 114 or determining the state settings of equipment controls through a connection with controller 220 In step 506 a decision is made based on the energy level determined in step 504 For exam
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