Guide
7 Signs Your Air Ducts May Need Cleaning (and When They Don't)
Duct cleaning isn't something every home needs on a schedule. Here's how to tell when it's worth doing, including the cases where it probably isn't.
Signs worth checking
- Dust or debris coming from the vents. Particles blowing out of a supply register are one of the clearer signs.
- Heavy buildup you can see. Take off a vent cover and use a flashlight. A thick layer is different from light dust on the cover.
- You recently remodeled. Drywall dust and sawdust can get into returns and boots.
- Signs of rodents or insects. Droppings, nests or debris in the ducts should be dealt with after the pests are gone.
- Visible mold on hard duct surfaces. Fix the moisture source too, or it can come back.
- Musty smells when the system runs. There are several possible causes, so it's worth investigating before paying for anything.
- You just moved in. You don't know what the last owner did, and a look inside gives you a baseline.
When cleaning probably isn't needed
According to the EPA, routine cleaning isn't recommended if none of these problems apply. Light dust on registers is normal, and duct cleaning hasn't been shown to prevent health problems. Be wary of anyone who makes health promises or says every home needs cleaning every year.
What to check first
Replace a clogged filter, check that nothing is blocking the vents, and take a photo of what you see behind a vent cover. If you're still unsure, an air duct inspection will tell you whether cleaning makes sense. We'll tell you if it doesn't.