Cooling the Closet?

My last grow saw high temps and I would like to fix that this time around.

Just a 2' wide x 3' long x 6.5' tall grow area in the closet.
If i counted the rest of the closet i'm not using for growing it would be 6.5' long.
(grow area vid)

For now I am vegging some Nirvana Bubblicious seedlings with CFL's but I would like to get a 400hps by flower time so I am trying to prepare ahead of time.

I have the blessing of having a 6" dryer hole cut into the bottom left of my closet already. So I have one hole to run some kind of ventilation.

It seems to me that exhausting the air would be more beneficial than bringing air in from outside. I can always open the closet door to get some new air in the grow area that way.

I have a small fan mounted in the top left corner of the closet with a bigger box fan that I converted into a swamp cooler about waist high blowing onto my screen, trying SCROG this time around.

Should I get a home depot 6" booster and hang it in the the top left of the closet and have ducting go to the dryer hole in the bottom left and exit outside the house? Or would that not be strong enough to keep temps in upper 70's?

The basic Home Depot/Lowes booster fans are cheap and fit the budget but will they keep my area cool or not? I only have one hole to use an exhaust fan so it has to be proficient by itself.

supposedly 160 CFM... What would be a sufficient CFM amount for my grow area?
http://www.homedepot.com/h_d1/N-5yc1vZ1xhl/R-100067594/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053

appreciate the help in advance, Thanks Guys!

anybody care to comment?

well thanks guys, I appreciate the help

160cfm will be good - Even with a 400watt light

you lucky dog, my closet has nothing to vent from, so i have to take the doors off and curtain the thing (still dont have the whole thing planned out yet, but i got some time til my nirvana beans come in as well)

as for the fan you linked, the above poster is probably right it should work fine. my question though is that dryer vent piped right out the the side of the house (through that wall)? if so, and this really only applies if you have neighbors, but those clear blades are going to increase the amount of light that escapes it which 'might' cause suspicion. obviously if thats the case even with non-clear blades some light will escape, but with the clear ones i imagine much more so.

Good point kloset King! nothing a lil black spray primer can't fix though I suppose. My concern is that with 5' of ducting attatched to that exhaust fan will it be strong enough then or will the CFM rating drop to the point of the fan not being proficient in cycling out the air through the ducting...

also the noise factor, the closet is in my bedroom and I need my beautry rest at night. So a loud fan would not be ideal. I get the overall impression of that fan ^^^^ that it's cheap, loud, short durability, but cheap and maybe ample for the job?

anybody have any good links to some cheap but effective exhaust fans? I think I am going to check out my local garden shop that I just discovered tommorow. Maybe they will have something decent so I can bypass the shipping and handling & I.D. theft of online commerce.

It's fun doing a closet grow though. The only battle is keeping temps down... Going to get a hygrometer tommorow so I can start keeping an eye on things untill I get this exhaust set up done right.