We incorporated Festool's dust extracting equipment into our preparation methods this year and we are glad we did. From surface restoration, general preparation, to sanding in between coats--sanding is a regular part of any professional painter's job. Festool extracts 96% of dust at the point of contact. HEPA filters are capable of capturing 99.997% of all particulates down to 0.3 microns. Most importantly, this means our workers are exposed to less dust during the sanding process, our clients are exposed to less seen and unseen dust floating around their homes, and we save time on cleanup (which means more time is spent on getting the job done).
More info from Festool about their dust extraction system that we use for our sanding and preparation methods.