Hi. I’m just setting up a new workshop and will be using an extractor like Axminster’s AT60E with a cartridge filter that catches particles down to 1 micron. But in the past, when I only had a cheaper HVLP canvass bag extractor, my plan was to house it outside the workshop in a small, dry but ventilated enclosure, and run ducting into the workshop (as well as an on/off switch of course). That way at least the fine dust wouldn’t float around the workshop - although neighbours etc would need to be considered! I never got to actually try this system though, as a divorce interrupted proceedings!
