What are the sources of air duct contamination?
All inside air was once outside air, so all of the dust, chemicals, pollen, insects and mold spores in the ouside air can be pulled into the air system. People shed millions of tiny dead skin cells every hour. Cooking smoke, household insect sprays, personal care products are also a source of pollutants. Many construction materials, carpets, wood products and plastics give off pollutants as well. During construction or remodeling activities, many types of dust are produced and find their way into the duct work. If the duct components were stored outside prior to construction, they may have collected dust, rain water and even mold before they were installed in a system.
