Thanks, yeah with the LED lamp too much heat will never be a problem, in fact I'm more worried about the room getting too cold since I will start growing on March 1 and this is Czech Republic so minus temps could be reached at night though the storage room is in my room which has heating, though the exhaust/intake is a small window which I can probably insulate a bit with some bubble wrap and tape.
I found a good deal on the fans, these are the ones I have available in the Czech Republic, (will keep 3 plants growing at the same time and 300 watts of LED, the space is about 55 cubic feet) I prefer to go budget but effective:
This one is 165 CFM:
http://www.growmarket.cz/vzduchotechnika/bez-regulace/tt-125mm280m3
what do you think, I want to pair it up with a carbon filter rated for it.
Also I can probably get a door draft stopper or even put towels on the gap under the door to make the room more air tight, although I noticed that tents are not 100% air tight anyways since they have an inlet to draw air and also for the cables.
The idea of not using tent is that I will save some money and also will have lots of head space in case the plant grows too tall because I want to grow sativas and also if they grow tall they could benefit from a second small but south facing window located at about 7 feet from the floor. I will put aluminum foil (bought at the supermaket, it works, right?) on the walls.
Also, the smell or the light doesn't have to be super stealth, this is Czech Republic and it is one of the most liberal countries in terms of weed, I have sometimes smelled fresh weed from my window which means a neighbor probably grows, I just don't want my apartment to stink or the neighbors to think this is a weed factory, so I guess I can make it with this setup, right?