How to Get Rid of the Smell in an AC Duct

Change your air conditioner filters. Over time, the filters become clogged with dust, grime and organic matter. If they are too clogged, they will not be able to filter the air, and will even contribute to the smell. Replacing your filters regularly is important.

Dust inside the ducts. If your air conditioner ducts are easily accessible, dusting or vacuuming their insides can help remove the smell. Although the dust itself might not smell, it can retain other odors such as cigarette smoke, mildew and general household smells. Dust gathers behind the front panel of the duct, so clearing it away might eliminate most of the smell.

Use an air sanitizer inside the ducts. Using an air freshener or air sanitizer spray inside the ducts and in the affected rooms can circulate the spray to areas that you might not be able to access yourself, removing some of the odor.

Look for the source of the smell. If simple cleaning and freshening does not get rid of the smell, it's possible that you have something in your AC ducts that is causing the smell. This could be a dead animal or the build up of lots of organic matter, such as leaves.

Get your AC ducts professionally cleaned. If you cannot get rid of the smell or identify the source yourself, you should call an engineer to look at the AC system. If the smell is being caused by mold, it is vital that you get your system inspected and cleaned, as mold can be dangerous for your health.