Many people wonder if their ductwork has mold inside of it.  This is a tricky questions because there is not a “golden” answer.  Ductwork is made out of metal which is non porous and mold can not “technically” grow on the metal itself.  If a duct system is dirty and contains layers of contaminants then mold could potentially grow on the debris inside of the ductwork.  You can see from the picture below that there is a significant amount of debris for mold spores to adhere to.

Proper cleaning of an air duct system and its vents can help reduce the amount of particulate coming out of the duct system and into your breathable living space.  Amistee Air Duct Cleaning specializes in whole house air duct cleaning.  If you are having a problem with indoor air quality or think you may have mildew or mold inside of your ductwork, get the cleaning done properly and do not waste your money with a company that could potentially make your problem worse.  Check with your local BBB and make sure the potential company is a member of NADCA.