I need help determining/brain storm a filtration/circulation system for an 8'x8'x8' grow room. Fully insulated stud walls.

400w highbay HPS with 8" A/C duct run to the room and mounted at the floor with vent. A ceiling exhaust vent hole that will push air through the attic approx 50" and mount to a roof turbine for exhaust. It will have a carbon filter on it prevailing the fan.

I was thinking of using one of these for the exhaust fan.

http://www.homedepot.com/webapp/wcs/...at-_-Bath_Fans

or one of these
http://www.iaqsource.com/product.php...product=111132

Please help with best product and best price.
I want to take in consideration for expansion of light wattage and exhaust capacity in the future.

Or this
http://www.homedepot.com/webapp/wcs/...ctId=100396529

Bump. Give me something to work with pro's This is my first set up.

If you're only using one 400W light, that won't be enough to light up an 8 by 8 area for one. Two, just air cool the light. Problem solved. Just vent the room every hour or so through a carbon filter to bring in fresh air passively and you're done.

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“Under my plan of a Cap and Trade system, electricity rates would NECESSARILY SKYROCKET.” -BARACK OBAMA

go with this one
http://www.homedepot.com/webapp/wcs/...ctId=100396529
its discreet ,it has the highest amount of cubic feet per minute,its cheap,and quiet

The 1st one is no good at all. The 2nd one is weak ,I have 1 of those. It moves air but not nearly good enough to attach any kind of filter to it. the 3rd one @ 800 CFM is obviously better but still isnt powerful enough to filter it. You want somthing with some sack! You need a centrifugal fan like > http://cgi.ebay.com/6-Valuline-Centr...3A1%7C294%3A50
Especially since you mentioned possible expansion.
And Mc is right if you want to use the whole 8X8 space one 400W is inadequate. Best of luck!

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My 1st grow Current growing adventures. My Gallery.

Thanks, I am aware that the 400 HPS isn't enough but It's all I currently have, going to spend money to get all necessities to make the room usable first. Then expand and upgrade over time.

A change of scenario. I got a 1000w HPS last night. What size fan should I use for this?

Keeping a 1000watt HPS cool can be hard. You need a powerfull fan. And you won't find it at home depot. Get this:

http://htgsupply.com/viewproduct.asp?productID=52583

I have two of these in my room. One for my room ventilation and one for just my light. What type of hood do you have for your light? No matter what type of fan you get, the light is still going to give off radiant heat. Some pics of your room would be helpful too.

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http://www.rollitup.org/grow-room-de...struction.html

A 1000! Good for you! Ok so you're not messing around. Get a cool tube man. If you don't you will wish you had. Seriously. Otherwise you just bought a heater for your growroom. http://www.ncwgs.com/reflectors_ultragrow_cooltube.php

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My 1st grow Current growing adventures. My Gallery.

The hood is not for growing. It is a 1000w HPS flood light similar to this http://www.lightmart.com/index.asp?P...D&ProdID=19753
but the bulb is mounted horizontal instead of vertical. The ballast, ignitor, and capacitor are all mounted in the hood also. I can easily cut some 6" holes on either side of the hood and build my own duct plenum/tap to mount inline filter, and duct to exhaust fan. What do you think.

I will get some pics posted soon. If they aren't up tonight, it will be atleast a week before I can post them as I will be out of town.

The true dims of the room are 8'x8'x7'