Majority of homes have inefficient filtration systems!
Contaminants build up inside the Supply and Return Ductwork. Heating and
Cooling Systems recirculate the air in a home via both of these Air Ducts.
Also homes do not need to be old to have concerns of dirty ductwork. When
New Homes are constructed the systems are often turned on which pull and
circulate construction dust through out the home. Not all Builders take the
proper steps to seal off the system and/or clean the system before the new
owners move in.