The dust shows up first. You wipe down the furniture on Saturday and by Wednesday there is a fresh gray film on it. A back bedroom never quite cools. The house smells faintly stale for the first ten minutes after the system kicks on. In Wilson County, where homes run their HVAC systems through humid Middle Tennessee summers and cold snaps that lean hard on the furnace, the ductwork behind the walls does more work than almost anything else in the house and gets looked at less. Add pollen season, pets, and the construction dust that settled into thousands of Lebanon and Mt. Juliet homes built in the last decade, and the buildup adds up quietly. This guide compares five companies serving Lebanon, Tennessee that clean and inspect residential an…