made this carbon filter with (i wrote up my build here search for it)
fiberglass door screen
i just place the filter on top of the fan.
its small and compact.
works ok but not great.
If I had to do it again and had the space.
I would use a speed controller + mixed flow fan + carbon filter.
Save the $s and heat issues.
When you upgrade your space (and You WILL), bigger fan is nice to have.