8 Signs Your Air Ducts Need Cleaning

Published 2026-10-26 · By the Crystal Air Duct Solutions team

The eight signs

1. Dust comes back fast. Furniture needs dusting again a day or two after you clean.
2. Gray rings around vents. Buildup on registers and return grilles.
3. Musty smell when the system runs. Common in humid coastal homes.
4. Smoky smell after fire season. Ash and soot settle in ducts.
5. Weak airflow in some rooms. Often a blockage, crushed duct or leak.
6. Allergies worse indoors. Dust, pollen and dander recirculating.
7. Recent remodel. Drywall dust and debris in the ducts.
8. No cleaning since you moved in. You cannot know what the last owners left.

Why coastal homes see it sooner

Humid marine air helps dust cling to the inside of ducts, and salt air finds its way into returns and attics. Malibu homes often need cleaning on the shorter end of the usual three-to-five-year range.

What to do next

Start with a duct inspection. We take photos inside the registers and returns so you can see the buildup before deciding on a cleaning.

Written by the team at Crystal Air Duct Solutions, an owner-operated duct and dryer vent company in Malibu, CA. Our owner has more than 20 years of experience.