How big a space can you just run exhaust fans?

[Owlfarm]

Hey everybody I've got an interesting question. I'm planning on building something new in the next year or two. Probably 40' by 50' building, possibly two story. Stick frame and insulated. I've never run a sealed room and never used co2. I live in a coastal area where temps rarely break 80 degrees. I've always just run open hoods and exhausted air. The most I've ever done this in is 15 600's and never had a heat problem. I just run a chiller in rdwc and the root temp stays cool. A 14'' max fan seems to do the job fine.
I'm wondering if this works on a larger scale? Greenhouse guys do it right? Just up the size of the fan so a lot of air is moving through the rooms? Like a 20'' fan instead of a 14''. Or will this not work as well in a larger room with 30 lights or more?
I'm thinking theres guys that have done this no problem, but I'm curious what people think.

 

[cannapits]

are you planning on using c02? if so then I wouldnt bother venting. im from the school of thought cool the room not the lights but thats just me.

 

[MarcoTC]

Sure you can. Just do the math on how much air you want to move. Try to filter the air as much as you can. The incoming to keep pollen, molds etc. out and the outgoing for the smell.
You cannot add co2 this way but you basically keep the co2 at 350-400ppm by constantly refreshing the room with outside air.

In a sealed room, you have total control over your climate but it can be a pain to keep things under control if it's a large setup. It's getting really expensive at some point as well.

I slowly moved from a large vented room to (semi-)sealed. I still vent during the dark hours in order to keep the humidity under control. It's just to stacked with plants to try to fight it with dehumidifiers. During the day, it's sealed and I use A/C and add co2.