This won't do much unless you can control temps to such an extent that you don't need to ventilate for a long time. The action of the yeast in creating co2 is much slower than the rising temp so what you will end up doing is evacuating most of your co2.

For co2 to work PROPERLY you need a SEALED ROOM, which means no intake or extraction fans and AIR CONDITIONING to control temps.

If you got your heart set on it don't use baker's yeast. It will die at very low levels of alcohol. Go to your local winemaking shop and get a yeast that will survive high levels of alcohol, I believe champagne yeast is the best. It's not expensive.
Perp Reviewed by Perp on . CO2 REACTOR, CARBON DIOXIDE cheap and easy DIY Hi all! My Engilish is crap, but lets turn back to business. Thi is my way of supplying CO2 for plants. Dissolve 100 gramms of shugar and 1/2 table spoon of bakery yeast in 500ml of WARM (below 40 degrees celcium). Leave at least third of space in the bottle. Reaction starts almost instantly if the bottle with solution plased in the warm place and this CO2 reactor will gain full power in 12 hour time . Connect any kind of elastic tube to the cap of the bottle of this solution and place Rating: 5