Economizer control

Abstract

An economizer control for controlling air quality. The economizer control includes a sensor that senses characteristics of air, a damper located relative to the sensor so that the damper can control air flow of outside air and re-circulated air to the sensor, and a controller in communication with the sensor and the damper. The controller controls the opening and closing of the damper according to conditions sensed by the sensor.

What is claimed is:  
     
         1 . An economizer control comprising: 
 a sensor that senses characteristics of air;    a damper located relative to said sensor so that said damper can control air flow of outside air and re-circulated air to said sensor; and    a controller in communication with said sensor and said damper, said controller opening and closing said damper according to conditions sensed by said sensor.    
     
     
         2 . The economizer control as recited in  claim 1  wherein said damper comprises: 
 an outside damper that allows outside air to enter a mixed air section of an air handler when said outside damper is open, and prevents outside air from entering the mixed air section when said outside damper is closed.  
 
     
     
         3 . The economizer control as recited in  claim 1  where said damper comprises: 
 an inside damper that allows re-circulated air to enter a mixed air section of an air handler when said inside damper is open, and that prevents re-circulated air to enter the mixed air section when said inside damper is closed.  
 
     
     
         4 . The economizer control as recited in  claim 1  wherein said sensor measures temperature, enthalpy and occupancy level.  
     
     
         5 . The economizer control as recited in  claim 1  wherein said sensor comprises: 
 a temperature sensor, an absolute humidity control sensor and a CO 2  sensor.  
 
     
     
         6 . The economizer control as recited in  claim 1  wherein said controller adjusts said damper to limit the amount of outside air entering a mixed air section of an air handler when said sensor senses a humidity level above a predetermined range.  
     
     
         7 . The economizer control as recited in  claim 1  wherein said controller adjusts said damper to limit the amount of outside air entering a mixed air section of an air handler when said sensor senses a temperature outside a predetermined range.  
     
     
         8 . A method for controlling an economizer comprising the steps of: 
 sensing characteristics of air; and    controlling a damper to control the air flow of outside air and re-circulated air in accordance with the sensed characteristics of the air.    
     
     
         9 . The method as recited in  claim 8  wherein said step of controlling the damper comprises the steps of: 
 opening an outside damper to allow outside air enter a mixed air section of an air handler; and  
 closing the outside damper to prevent outside air from entering the mixed air section.  
 
     
     
         10 . The method as recited in  claim 8  wherein said step of controlling the damper comprises the steps of: 
 opening an inside damper to allow re-circulated air to enter a mixed air section of an air handler; and  
 closing the inside damper to prevent re-circulated to enter the mixed air section.  
 
     
     
         11 . The method as recited in  claim 8  wherein the step of sensing characteristics of air comprises the step of sensing the temperature, enthalpy and occupancy level.  
     
     
         12 . The method as recited in  claim 8  wherein the step of sensing characteristics of air comprises the step of sensing the temperature, absolute humidity and CO 2  level of the air.  
     
     
         13 . The method as recited in  claim 8  wherein the step of controlling the damper comprises the step of adjusting the damper to limit the amount of outside air entering a mixed air section of an air handler when a humidity level above a predetermined range is sensed.  
     
     
         14 . The method as recited in  claim 8  wherein the step of controlling the damper comprises the step of adjusting the damper to limit the amount of air entering a mixed air section of an air handler when a temperature outside a predetermined range is sensed.  
     
     
         15 . A system for controlling an economizer comprises: 
 a means for sensing characteristics of air located in a mixed air section of an air handler;    a means for controlling a damper to control the air flow of outside air and re-circulated air in accordance with sensed characteristics of the air.    
     
     
         16 . The system as recited in  claim 15  wherein said means for controlling the damper comprises: 
 a means for opening an outside damper to allow outside air enter a mixed air section of an air handler; and  
 a means for closing the outside damper to prevent outside air from entering the mixed air section.  
 
     
     
         17 . The system as recited in  claim 15  wherein said means for controlling the damper comprises: 
 a means for opening an inside damper to allow re-circulated air to enter a mixed air section of an air handler; and  
 a means for closing the inside damper to prevent re-circulated air from entering the mixed air section.  
 
     
     
         18 . The system as recited in  claim 15  wherein said means for sensing characteristics of air comprises a means for sensing temperature, enthalpy and occupancy level of the air.  
     
     
         19 . The system as recited in  claim 15  wherein said means for sensing characteristics of air comprises a means for sensing the temperature, absolute humidity and CO 2  level of the air.  
     
     
         20 . The system as recited in  claim 15  wherein said means for controlling the damper comprises a means for adjusting the damper to limit the amount of outside air entering a mixed air section of an handler when a humidity level above a predetermined range is sensed.  
     
     
         21 . The system as recited in  claim 15  wherein said means for controlling the damper comprises a means for adjusting the damper to limit the amount of air entering a mixed air section of an handler when a temperature outside a predetermined range is sensed.