The crew from Clean Air + could tell you some stories about ducts. In the years they've been cleaning residential airways, they've not only cleared out dust and allergens, but have rescued toys, tools, food, and soda bottles. These foreign objects create more surface area for dust and debris to stick to, resulting in air rife with more mold, bacteria, and other allergens than the inside a dust mite's lunch box. As the techs clean, they can also inspect ductwork for leaky connection, fallen insulation, and kinks that might restrict air flow.