ventilation for 4x4x6.5 grow tent

[Farmer J]

I purchased a 4x4x6.5 grow tent and Im looking at the materials I need for ventilation.
http://cgi.ebay.com/New-4x4-x-6-5-HYDROPONIC-GROW-TENT-HYDRO-BOXHUT_W0QQitemZ360062134499QQihZ023QQcategoryZ43555QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

There is a 4" flange outlet at the top back of the tent and two 6" flange outlets on the top and one on each side.

To utilize these, I would assume I need the following (please provide your opinions): As the cubic feet is 20.8 (4x4x6.5 = 104 /5 = 20.8), I dont need much.

List:
1 x GrowBright 4" Inline Fan & Elf Carbon Filter Combo
http://www.htgsupply.com/viewproduct.asp?productID=52531

- I will also use an inline fan for my ballast.
- I already have a 6" oscillating fan.
- I need to find a light proof fan to install at the bottom for air intake.

Feedback is much appreciated!

http://img501.imageshack.us/my.php?image=70270156fq7.jpg

 

[HMGanja]

Well first off, why did you divide by 5 for cubic ft? You had it right though with 104 cubic feet. But the fan you picked out is a 170cfm so that would be fine for extraction. Second, are you planning on useing a air cooled hood or just a standard one. Both situations have diff. ways of being done. If you are using a air cooled hood, you could either pull just from the bulb and extract, or pull from the tent and the bulb at the same time. This will determine how many and what kind of fans to get. I would think of a way to create a light baffle that you could use as a passive intake as well. And what do you mean by using a inline fan for your ballast?

 

[HMGanja]

Just noticed your second link. I assume you have a light with a built in ballast and thats what you mean by using the fan. If thats the case, I would defenitly cool it seperate. What you have planed looks good. I would use the 170 to vent the tent itself and maybe a 125 for the light/ballast. As far as venting out the window......as long as security and stealth is not a concern, go for it. Would think about mounting fans outside the tent as well due to the added heat they generate.

 

[Farmer J]

I live in a penthouse on the 32nd floor so bypassers is not a problem. I want the windows open for vent.

 

[HMGanja]

Well that works. Shoot, in the winter you can let it dump into the penthouse and save on the heating bill!