I've been in the hvac trade over 35 years .the number1 reason you may have a dusty ,musty smelling home isn't because the duct work is dirty but because it's "LEAKY" it sucks air in from the crawl space and distributes it through out your home .I install 100% sealed ducts on my premium quality re-ducts and this will save you a lot on your energy cost also .all systems are "R-8" VALUE INSULATING FACTOR, and are way above what you'll get from any other contractor in the Nashville area .I also will do photo inspections and evaluation's on crawl space conditions and can do a 48 hr. "RADON" test with an EPA approved device. I personally do all the work myself ,not hired help .I have many, many references in the Nashville area.you can call me personally at