grow room ventilation advice needed

[karaRYO]

I have a new 24' x 8' flowering room. Can't affor to close it up and cool with hvac so am looking for the best alternative. My idea so far is to have a 10" exhaust fan up high and a passive vent or two down low.
I'd like to have everything set up with a digital thermostat that would keep me within 3 degrees of my set temp. When things got too warm the vent or vents would open and the fan would kick in pulling hot air out and bringing cool air in passivly through the vents until my set temp was met. Also will need some kind of filter on the vent to keep bugs out. Anybody know of a system like this on the market? also feel free to shred my idea. I'd rather hear about problems up front than learn about them after the fact. Thanks for the help.
Shelly

 

[Volsam]

Have as big exhaust as possible, if 12" available, go for it. Try not to get cheapest fans - they are too noisy. A lot of times in smaller places forced fresh air intake needed as well. Could be done by using smaller in-line fans with aluminum dryer vent hoses. Also make sure the placement of your ventilation is correct according to light fixture position (the main source of heat). You can make it all on your own - just stop by one of the construction supermarket.

Good luck!

 

[thujone]

for such a large volume of air, centrifugal fans are most efficient at producing a good pressure gradient. for the passive intake vents, good light traps should also help in keeping bugs out.