Before and After cleaning (7 years accumulated dust)

ALL air ducts, old and new alike, can be contaminated with harmful debris, viruses, mold, pollen, pet dander, fiberglass, and other allergens and particulate. 
    New homes air ducts, though they may not have had the time to build up layers of mold and much visible debris, are usually contaminated with building materials such as sheet rock dust, sawdust, and, many times, nails and other leftover matter.  Viruses are unique in the fact that they need a carrier to infect.  They use these visible and microscopic particulate to ride on as they float in the air - where you breathe them in!
    Older homes (5+ years) have even bigger problems.  Dirt and debris, many times mold and viruses, have been building up for many years, unknown to residents.  Since the awareness of harmful contaminates  is relatively new to consumers attention, most homes have NEVER been cleaned.