I don't think an 80 cfm computer fan will clean much if any smell, it's just too small. From my experience, you're going to need 400 cfm+ to pass air through a carbon filter. The 80 cfm may or may not be enough to exchange air in the grow area depending on temps, etc. In this instance, you would use a larger fan for the smell, all within the grow area, and a smaller fan to exchange the air.
Best of luck,

Dan