Thanks for the great info... I can see taking one of these and putting a high grade filter on the top and a small fan to pull the air out at the bottom. Might be overkill, but could be helpful. Another, more expensive, option that I saw looking at the web is a whole room air purifier. Kinda pricy but this would allow all of my equipment to be subjected to much less dust... and I can use it when I move into my permanent darkroom once we move.
http://www.amazon.com/dp/B002VXDCHW?psc=1
I also saw these:
http://www.amazon.com/Vent-Mate-Regi...ds=vent+filter

Anyone use either of these options?
Jim