So consider getting air conditioner filters or furnace filters that do not generate any ozone. Prescription Checklist: Change or clean your furnace and air conditioner filters once a month or according to the filter manufacturer’s instructions. Increased dust could be a sign that it is time to change a dirty furnace or air conditioner filter or vacuum cleaner bag. my furnace air conditioner filter seems to contain an inordinate amount of dust despite regul… my furnace air conditioner... more