minimum CFM for my grow room

hey guys what do you think a good CFM is for a 48x24x60 (4x2x5) grow room? also maybe pros and cons of inline ducking fan like this

http://www.ebay.com/itm/4-inch-INLINE-DUCT-BOOSTER-FAN-exhaust-blower-cooling-/160632452339?pt=LH_DefaultDomain_0&hash=item256670b4f3

or the more common inline fan like this

http://www.ebay.com/itm/4-Fan-Carbon-Filter-Combo-Inline-Odor-Control-Scrubber-/300591431680?pt=LH_DefaultDomain_0&hash=item45fca54000

one more question how big should i go, i want it to be a quite as posable. i was thinking 6in but i have 4, 6, and 8 inch hookups

thanks

here is a online CFM calc: http://www.csgnetwork.com/airexchangecalc.html

thanks dude +rep!

how many times per hour should are be evacuated?

and what does the option mean below that [FONT=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]

Target Air Handler/Fan's Airflow[/FONT]

yah u know what that isn't the one I was thinking off, i'll post it when i find it

Here we go…*http://www.phreshfilter.com/selector.php
- this will give you the CFM…*then you just look at what the CFM is rated on the fans your looking at.

if it helps any… i'm using a 4.5'x4.5'x7' tent using a 6" fan rated at 340CFM