Saw this today while cruising the internet...what a great idea!! Just put a big square air filter on the air intake side of the fan using hook-n-loop tape and there ya go! I think this would be a big help in controlling the dust...hope someone can use this idea!
You can go as far as building a box for the fan and install 2 filters, different porosity to keep the filter closer to the fan cleaner. Many woodworkers have made these and they're cheaper then my big filtration unit.