Don Beale is the person to ask--he used to be in this line of work. Hopefully he'll chime in.

: I had to replace the fan unit in my attic when my roof was redone. The
: plastic housing was cracked. Any suggestions for building some kinda
: filter system using the old fan. The fan is probably 14-16 inches in
: diameter..

: Would a simple box with the fan inside surrounded with filters do me any
: good?

I think so.

: What kind of filters?

Furnace filters. Use a pair of el-cheapos back-to-back as a prefilter before the fan, and then a good Hepa filter on the outflow end.

Don F: I'm with Mark. Stick with the vacuum cleaner attachment. It's no fun, but it's probably more healthy. How about a hose hanger up with your stereo headphone wire hangers?

Shawn