Yes, it definatelly matters.

Heat rises, so putting the active (fan forced) exhaust up high, is best.

Passive (no fan) intake near bottom, but be careful of light leaks from both. Not necessary to cut that big of intake holes. You can likely get away with smaller. (2")

You'll need a circulation fan for inside the cabinet, too. (exhaust and intake don't work well alone, so additional air circulation is needed.

Have you taken a look at other wardrobe conversions, for guidance?
Rusty Trichome Reviewed by Rusty Trichome on . Ventallation Question Ok, I have my new cabinet that I am going to use as a garden. My only question is where I should have spaces for ventalation. I am guessing that since there are two sides, I will need two vent's for outgoing, but where should i put them? On the top, or towards the bottom? Or does it matter? I will be using duct fans to push air out (and in, i suppose), so I will have a bunch of 4" holes when its done. Anyway, can someone take a look at the unit here and give me an opinion? Thanks Rating: 5