In my area and janitorial contracts I dont get much dust. Or pet hair. This windsor is 6 yrs old, covers 2500sq ft per night 6 nights a week. In 6 years I've changed one belt, and one brush roll. Just bags and filters besides that. And that is with employees doing a large portion of the use. Female employees. And we all know they arnt vacuum mechanics. I think in businesses vacs last longer because they dont get picked up to be put in Van's, and we dont have the pet hair. We get more mud clumps because it rains 80in per year here. These things are tanks for vacs. I'd guess 80 percent of schools use these.