Making my own co2

I plan on making my own co2 with yeast and sugar. Would it be better to put the end of the bottle where to co2 comes out above my plants or in front of the oscillating fan I have in my grow room its on the floor pointing up toward my plants.

i use plastic piping running from two 2 liter bottles right behind the fan , the fan sucks the co2 in and blows it out
as cot is heaver than air it drops, or just have it flowing out from above the plants

Ya a fan would be best. I just made my own too but with vinegar and baking soda. Theres a bunch of videos on YouTube. I put vinegar in a milk jug and attached an empty plastic snapple bottle and got some tubing from the pet store for fish tanks then when u drop a couple tablespoons of baking soda in it the co2 filters through the water in the 2nd chamber then the tube goes out thru my fan