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.

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.