I am planning to grow in my closet, 4x3x8 making it 96 cubic ft. I found a 95 CFM fan.

Question 1:

Should I have a 95 CFM fan for each the intake and exhaust, or is it possible to hook up both to one fan?

Question 2:

Where is the best place to locate the Carbon filter? (getting a carbon-filter + fan setup is a possibility)

The closet is not air tight, it has sliding doors so there are gaps.

If I were to have a separate fan for the intake and exhaust, would the carbon filter work effectively if I hooked it up to the intake fan? Meaning the fan would blow air through the carbon filter, through a couple feet of ducting and into the grow room.

u would prob want 2 fans..intake and exhaust
and the carbon filter is for smell so u need to have it hooked up to the exhaust so the air goes thru it before leaving the room

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LATAS

Since your closet is not sealed then if you have an intake fan, and an exhaust fan then you run the possibility of the odor coming out of the cracks of the doors. If you just use and exhaust fan then you would cut a small passive intake since you alread have some intake from the cracks in your doors. Since the air would constantly be flowing into the closet then you would not have to worry about the smell escaping. You would want to place the carbon filter up high in the closet then suck through it and blow out of the closet. you can also put the carbon filter out of the closet and place the exhaust fan up high into the closet. However this way you have to try to hide a carbon filter outside of your closet. My two Cents.