Air duct cleaning means having all your duct system, including the supply, intake and return vents cleaned using professional air duct cleaning equipment. In addition, air duct cleaning may also include cleaning the registers, grills, fans, the HVAC unit and cleaning the furnace if you have one. Air duct cleaning companies, like Dustless Duct, have a variety of professional duct cleaning equipment designed to clean your air ducts and make them a healthier living environment in your home. Having your air ducts cleaned is recommended every three to five years, though in some cases two to three years would be the optimal time for best results and maintenance.