Ventilation blower controls employing air quality sensors

Abstract

A fresh air ventilation system in a building having an outside wall exhausts contaminants, such as stale or noxious air, through the outside wall and takes in fresh air. A remote switch sets a mode of operation of the ventilation system. One or more strategically placed air quality sensors are located within the building. The sensors may be connected wirelessly through a multiplexor interconnect system to operational control the fan of the exhaust system. In response to the detection of a contaminant above a pre-selected level by a sensor, the relay controller for the sensors resets the remote switch for continuous high speed operation to evacuate the contaminants from the building through either special ducts or the conventional air ventilation ducts within the building.

1 . A fresh air ventilation system in a building having an outside wall, said ventilation system having means to exhaust stale air through said outside wall and take in fresh air, the improvement comprising: at least one air quality sensor at a specific location within and/or in vicinity of said building; and controller means in response to the detection of a contaminant above a preselected level by said at least one air quality sensor for controlling said fresh air ventilation system to take appropriate action; and a relay added to said existing ventilation system, said relay having contacts connected to respective remote switch terminals such that said relay is capable of setting continuous high speed modes of operation of said fans of said existing ventilation system; and,
 said at least one air quality sensor being connected in a parallel network to said relay so that when said at least one air quality sensor detects an abnormal air quality condition of air within said building, said relay is activated to set high speed operation of said fans.   
   
   
       2 . The fresh air ventilation system as in  claim 1  wherein said at least one air quality sensor is a plurality of sensors. 
   
   
       3 . The ventilation system of  claim 2  in which said sensors are located in a stale air plenum of said ventilation system. 
   
   
       4 . The ventilation system of  claim 2  in which said sensors are located in different areas within said building. 
   
   
       5 . The ventilation system of  claim 4  in which said sensors are related from the group consisting of a carbon monoxide detector, a smoke detector, a fuel gas detector, and a radon detector. 
   
   
       6 . The ventilation system of  claim 4  in which said sensors are selected from the group consisting of a relative humidity sensor, an ammonia sensor, and a methane sensor. 
   
   
       7 . The ventilation system of  claim 1  having a controller for displaying and sounding out an alarm when said at least one sensor detects a hazardous condition. 
   
   
       8 . The ventilation system of  claim 2  in which said sensors produce wireless signals and said ventilation system has a multiplexor for receiving said wireless signals and sending them to a master transceiver for interfacing with said controller. 
   
   
       9 . The ventilation system of  claim 2  wherein said controller means is hard wired to said air quality sensors via separate terminals. 
   
   
       10 . The ventilation system of  claim 2  wherein said controller means is connected to said air quality sensors via a multiplexor using a single pair of wires with sensor address recognition. 
   
   
       11 . The ventilation system of  claim 2  wherein said controller means uses priority logic to resolve situations calling for conflicting actions. 
   
   
       12 . The ventilation system of  claim 2  wherein said controller means shuts down system fans to restrict a detected outdoor contaminant from entering said building. 
   
   
       13 . The method of ventilating a building comprising the steps of: using a fan to exhaust stale air from inside said building and bringing in fresh, outside air; setting a mode of operation of said fan using a remote switch; adding a relay to said existing ventilation system; using sensors within said building to measure different air quality conditions in one or more locations within said building; connecting contacts of said relay to said remote switch terminals such that said relay is capable of setting continuous high speed modes of operation of said fans of said existing ventilation system; and,
 connecting said at least one air quality sensor in a parallel network to said relay so that when said at least one air quality sensor detects an abnormal air quality condition of air within said building, said relay is activated to set high speed operation of said fans and overriding the setting of said remote switch when an unfavorable air quality measurement is taken by any one of said sensors to operate said fan at a continuous high speed.   
   
   
       14 . A point source exhaust blower controlled by a plurality of air quality sensors to automatically exhaust contaminated air from a room. 
   
   
       15 . The point source exhaust blower of  claim 14  wherein said air quality sensors are selected from the group consisting of a relative humidity sensor, a methane detector, and an ammonia detector. 
   
   
       16 . The point source exhaust blower of  claim 14  wherein said room is a bathroom. 
   
   
       17 . The point source exhaust blower of  claim 14  wherein said room is a laundry room. 
   
   
       18 . The point source exhaust blower of  claim 15  wherein said air quality sensors are in a parallel network controlling the operation of a relay which operates said blower in response to detection of a contaminant by at least one of said air quality sensors. 
   
   
       19 . A carbon monoxide ventilation system comprising: a) a building having a wall with an interior mounting surface and an exterior surface adjacent to ambient outside air; b) a furnace within said building with a supply duct for circulating heated air through the interior of said building and a return air duct for circulating return air through said furnace; c) a normally open powered first damper in said supply duct downstream of said furnace forming an air supply plenum between said furnace and said first damper; d) an exhaust vent in said wall; e) a vent duct between said exhaust vent and said air supply plenum; f) a normally closed powered second damper in said vent duct; g) a carbon monoxide gas detector in said air supply plenum; h) control means in response to said carbon monoxide detector sensing a threshold value for carbon monoxide gas for actuating said first damper to close and said third damper to open, thereby diverting carbon monoxide gas laden air in said air supply duct out of said building; and, i) said building having a fresh air inlet vent, a fresh air supply duct between said fresh air inlet vent and said supply duct downstream of said first damper, and a normally closed powered third damper within said fresh air supply duct, said control means actuating said third damper to open when said first damper is closed thereby delivering fresh, outside air to the inside of said building when a dangerous value of carbon monoxide gas is detected in said air supply plenum said control means having at least one relay added to said existing ventilation system, said at least one relay having contacts connected to respective remote switch terminals such that each said relay is capable of setting continuous high speed modes of operation of said fans of said existing ventilation system; and,
 said at least one air quality sensor being connected in a parallel network to said at least one relay so that when said at least one air quality sensor detects an abnormal air quality condition of air within said building, said relay is activated to set high speed operation of said fans.   
   
   
       20 . The ventilation system of  claim 19  in which said control means comprises a control module which is interconnected with said first, second and third dampers for controlling simultaneous operation thereof. 
   
   
       21 . The ventilation system of claim  19923  in which said control module is connected to a thermostat within said building through a junction box on said furnace for resetting the thermostat when said dangerous value of carbon monoxide gas is detected. 
   
   
       22 . The ventilation system of  claim 21  in which said control module has a separate source of electric power. 
   
   
       23 . The ventilation system of  claim 22  in which said control module has an LCD liquid crystal display, a key pad for inputting information, an alarm for broadcasting the presence of excessive carbon monoxide gas, and a status light. 
   
   
       24 . The ventilation system of  claim 23  in which said carbon monoxide gas detector has two threshold values, a lower threshold value for providing a warning and an upper threshold value requiring immediate closing of said first damper and opening of said second damper.