I found this interesting site on the subject of air-borne wood dust. This guy has over-engineered everything for an awesome system. I want to build one some day with the clear acrylic cyclone cone.

http://billpentz.com/Woodworking/Cyclone/index.cfm

http://billpentz.com/Woodworking/Cyclone/medicalrisks.cfm

He is sensitive to wood dust and this allows him to still work wood.

My current system includes a vacuum or a ex-clothes dryer fan. Lol

Don T

: I deal with airborn dust with a 20" fan attached upside down
: to the ceiling - so I can reach the on-off switch. I attached
: four home-made clips to the intake side which hold a furnace
: filter, that does an excellent job of removing wodd dust: even
: after power sanding cedar I can remove my mask after 10 minutes.
: The filters don't last long but they are cheap. This is as well
: as - not instead of - regular cleaning and vac pickup for
: dust-making tools. During the summer I do a final cleanout
: occasionally with the doors open and a leaf blower to blast out
: the the hidden corners, especially the day before painting.

: Speaking of workshop fires, been there, done that; it isn't good
: enough to keep the place clean and avoid storing oily rags
: together and all the usual stuff I plug every power tool before
: I leave, but that day there was an electrical fire just started
: in a corner when I closed up. So now I have another rule: unplug
: and put away extension cords. You can't be too careful, and even
: that's sometimes not enough.