Filters have a efficiency rating called MERV, ( Minimum Efficiency Reporting Value). The higher the MERV rating , the cleaner the air and the better the equipment protection. Control dust, dirt, and pollen with high quality filters and/or air cleaners.
Plug leaks with weather stripping and caulking. Caulking and weather stripping let you manage your ventilation, which is the deliberate controlled exchange of stuffy inside air for fresher outdoor air. To learn more about indoor air quality in your facility visit the Environmental Protection Agency's EPA Indoor Air Quality.