At Clean Air Systems we follow an ethics code set out by the National Air Duct Cleaners Association (NADCA). Their belief is that you can’t put a timeline on how often the cleaning should be done. Each home is different and each family has a different lifestyle, both of which affect how often you should have your air ducts cleaned. You don’t go years between vacuuming the carpet on the floors in your home so you shouldn’t go too long in between cleaning your air ducts. For best results, your air ducts can be cleaned every three years; however, asthma and allergy sufferers may want to get their air ducts cleaned more frequently.