I didn't understand until I reread your post. Can't answer definitively, but I think you might run into issues trying to push air all the way through 10" of carbon. 90CFM doesn't seem like it would do it. Plus, it seems a bit inefficient, you would lose a lot of airflow if it does work. You need either something of smaller diameter to put inside (and a lot of drilled holes) to make something like the filter from this post, or two 4" diameter pieces of screen so that you can have something like || || . The air would go through the first screen of the can, through carbon, through one of the screens you make, through empty space, through the second screen you make, through carbon again, then the final screen. I hope that makes sense. You would have carbon on both ends with empty space in the middle and the air would filter twice.
Only way to know for sure though, is to try it your way first. Some fans have better resistance against back pressure than others.
I put 2 pieces of cut to fit filter screen on the bottom and filled with carbon, another 4" circle of screen, more carbon, etc... untill the can was filled. I used 2lbs of carbon to fill it. My question is will a 90 CFM booster fan be able to pull enough air through the can where it has a 4" opening on each end but nothing on the sides? will I have to drill/machine holes/slots in the can? I would assume I would use more of my carbon with out the holes/slots as air will have to travrel the entire 10" length of the can. Sorry if I confused anyone I'm typing fast before I head out to work.
