I picked up a generic air scrubber on-the-cheep a few months ago ($100). Previous owner had no idea what it was and confused it with a compact dust collector. Was definately used by original user for laser cutting as there was a ton of pitch to clean out. Original 3" heppa filter was too coated with pitch to use and needed replaced. I just tried to use it the other day for the first time cutting a small acrylic template and my basement was uninhabitable for a few hours. Pulled all the activated charcoal pellets (maybe 3.5 gallons of such), washed them and worked them through a burn-off cycle in a rotarary tumbler on my grill at about 600 degrees to reactivate them. End result was no smell and a neutral grey of the pellets. Ran a quick test with a wood cut and was less than thrilled with the resulting smell. Am I expecting too much or should the air scrubber be able to pull all smells from the cutting process? Unit is 3-chambers. First is general 1-micron pocket filters. Second is 13 merv Hepa. Third is bulk loose activated charcoal, about 3.5 gallons (20 lbs?).