The honest picture
You may have read that dirty ducts cause illness. The EPA states that duct cleaning has never been shown to actually prevent health problems, and that a light amount of household dust in ducts is not known to pose a risk. The real risks of neglect are more practical.
Risks that build quietly
Pests
Damaged or disconnected duct runs in the attic give rodents and insects a way in. Nesting material and droppings can end up in the system.
Moisture and mold
Condensation, a blocked drain line or a roof leak can wet parts of the system. In a humid climate like Austin’s, that can lead to growth. See air duct cleaning and mold.
Leaks
ENERGY STAR estimates that a typical duct system loses 20 to 30 percent of the air it carries to leaks, holes and poor connections. Return-side leaks can also pull dusty attic air into the house.
Dirty components
Dust that gets past the filter collects on the blower and coil. ENERGY STAR notes that dirty coils reduce cooling and make the system run longer, and that airflow problems can cut efficiency by up to 15 percent.
What to do about it
- Change or clean the filter on schedule.
- Have the equipment serviced before summer and winter, including the evaporator coil and blower.
- Ask for an air duct inspection if you notice pests, moisture, dust blowing out of vents or rooms that never cool.
Our article on common air duct issues explains which fix matches each problem.
