small growroom. . exhaust suggestions. .

ok so im planning to build a 3'X3X'6' growbox/room with a wood frame and pandafilm. . im going to be running a 400w hps so my question is, which would be the best way to set up the exhaust with the fans i have. . right now i have a 4" vortex 172 cfm and im planning to get a cheap booster fan either 4" or 6" either way weaker than the vortex . . i was thinking of putting the booster fan on one of the bottom sides blowing cool air from outside in. . and the vortex on top blowing hot air out and also just some fan blowing air around in there. . the box is going to be right next to a big sliding glass door, so the ducting is going to have easy access to the outside. . does that sound like it would work and keep the enviornment pretty good? i was fighting powdery mildew my last crop because of humidity also.. i was planning to do 4 clones (2 cheese, 2 afghani bullrider)let them veg for about a month maybe more if they're not big or should i try to fit more clones into that space and flower them sooner? and for the record this took forever to type up all baked.. it just doesnt sound like it makes sense. . anyways.. any input would be appreciated..

You sound like you have a good idea of whats needed, circulation and fresh air. Intake fans are unneccesary though, a passive intake slightly larger than your exhaust is all you need. The air ideally should be refreshed every 5 mins, your room is 3x3x6 = 54 cubic feet, and your fan blows 172 cubic feet per minute, so additional ventilation shouldn't be required. Get a small oscillating fan to keep air moving inside the growroom and your stems will grow stronger from being moved around, and be able to support heavier buds later on. Make sure to exhaust from the top, where air is warm, and intake from low down, but you knew that anyway!
Are you planning on cooling the bulb in any way? It would allow you to get the bulb closer to the tops of the plants, and make the most of the light. 4 plants in a 3x3 area should be comfortable, lot of ppl might say put 9 in there but if you lst your four cuttings, you should nicely fill the space you have.
I like your choice of cheese, I harvested my first crop of it 6 weeks back, only got 1 1/2 oz from 2 plants since I had to pull em down 3 weeks early due to security concerns. Still a really nice smoke despite being early, and so far I've barely smoked half an oz, normally I'll do an 1/8 to a 1/4 every week but this blows me away!
Good luck to you, keep us posted on how things turn out.

thanks for the input! no, im sort of on a budget so i cant get my light air cooled. . dont really want a cheesy diy one either, i figure the vortex sucking up the hot air by the light. . a 6" intake down low. . and like you said with the oscillating fan moving air in the room, that should be ok right? yeah. . the most plants ive done is 4, i veged them for a month. . then flowred. . by the time they where done it was very difficult to manage . i couldnt even imagine trying to care for 9 right now. . even if they veg for a shorter period. . plus you prob need extra nutes. . . i agree, with seeds ide want to do more.. but since a friend has many mother plants. . cuttings is the way to go.. and they do fill in very fast. . so would you say the cheese is a good yielder. . if it would have finished? ide like to get 1.5 - 2 oz. of each plant. . what size pots did you use? and how long did you veg for? if you dont mind me asking. .

Waldo, if anything, i would use both of those fans for exhausts and not in-takes. But even then it may be overkill because your vortex will work nice - so I would use a passive in-take, like bob said....find a light trap of some sort......louver, make it out of cardboard (see my sig). Also, I might get 2 oscilating fans in there...one right on the bulb, and another on the plants. And don't forget, the ballast puts a good amount of heat out also...where will that be?