House Smells Like Mold But You Can't See It? Follow These HVAC Tips
If your house suddenly has a musty odor, but you can't find the source of the scent, check your air ducts. Mold is an airborne contaminant that can grow anywhere if it finds a good food source. If your air ducts contain moisture and organic matter, such as pet dander and bacteria, mold can live and grow inside them. The musty odor produced by mold can invade your living space every time you turn on your cooling system.