Hello , sports fans!
Well, there are so many things floating up in my head, i need to get them out. Not necessarily in an organized form, but we'll see:
1. ( I guess by putting numbers, it automatically became organized. Yea me.) We are running into focus issues.  Originally slated to create an exhaust fan whose speed depended on the CO2 concentration, turned into VOCs. We tested several VOCs that we were comfortable with breathing in the room (Isopropyl alcohol, Pine-sol, Acetone and ammonia) and compared them to the Grey Wolf to correlate the voltage given off by our sensor to the ppm observed by the Grey Wolf. Pine Sol was a hot mess with seemingly no correlation; just vomited points on a graph. The windex (ammonia), isopropyl and acetone had better curves, with acetone being the least precise.
2. Looking at the health risks of windex and isopropyl, the dangerous levels are far above what the sensors can read. So, do we provide proof of concept, or try out some other VOCs at a toxic level in the room we are in? If you guessed proof of concept, you are correct!  What we are currently doing is programming the arduino hooked up to the sensor to trigger an exhaust fan to come on when the isopropyl concentration reaches 2500ppb.  As the concentration increases, the fan speed will increase to its full value when 21000ppb is reached. This is only proof of concept the lower level of health safety is 400000ppb.  The lower limit of explosivity (I made that word up)  is even higher, at 20000000ppb.
3. So how is our presentation going to work? Here's what can be done if we had the part? No one needs a ventilation system if the air quality is fine...
4. Assuming the concept works with CO2, how feasable is it to evacuate the air from, say, a classroom?  You cant just turn the HVAC system on...that would just recycle the air already in the building. It would have to vent to the outside like a Chemistry vent hood. No one is going to do that with a building that is already built. It would be incredibly expensive. Where would the new air be coming in from? If the temp outside is considerably different from the inside, that new air will have to be heated/cooled which cost additional money.
5. How powerful a fan is needed for a room? How loud would it be? Where would it be mounted? CO2 is heavy so the fan might need to be low...

out, Dave