well i had my duct work cleaned which has never been cleaned out, it was suggested by home comfort experts salesmen when i had my new heating and cooling unit installed well, i had it done boy was it dirty, the tech walked me threw the process what he was going to do, and was very curtious and answered all my questions i had . he was very neat and cleaned up after himself he was very meticulous about his job i would highly recommend home comfort experts for all your heating and cooling needs.