Building Grow Closet! Need help with Exhaust

I have a closet that is 2 feet 10 inches wide x 2 feet 6 inches deep x 8 feet tall. It is in a basement that stays a consant 60 degrees. I wil be running a 400w hps or a 400w ms light and ballister with co2 setup. That should make the room about 72 cubic feet. I will be using an aeroponic system that is being custom made. My question is if I put my exhaust at the top with a scrubber that should push the hot air out of the room since hot air rises, without any smell right. Then I should have a fan at the bottom pulling fresh air in the room. How big (CFM) of fans should I use for this should the exhaust fan be stronger than the intake fan or vise versa? Should i have more than one exhaust fan and two intake fans or vise versa or just one of each the same size? I am sure the temperature will go up a lot in the closet when I turn the lights on. Any help would be appreciated!

Jeez... a lot of questions here.

One exhaust and one intake should be more than enough. Your exhaust should be the stronger of the two, because it will make use of passive suction. Also, it will ensure that the smell is sucked out, which I assume would be beneficial for your circumstance.

Good luck, I am sure you are on the right track.

go for an in line fan - and hook it up to a carbon scrubber

filter - in line fan - coolshade

go for a 125mm fan and buy a mains dimmer switch so you can control the speed and noise.

I got one off of ebay for £3. It's surprising how much of the noise is created by running the fan at it's full output.

how much would an in line fan cost

Don't control fans with a light dimmer. Very few fans can be safely controlled that way.

You need an AC motor speed controller, of some variety. The "router speed control" at harbor freight will work (as long as it's not a slow-start motor.)

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