facebook noscript

When Your House Smells Like a Gym Sock: Blame Your Return Air Ducts, Not Your Teenager

Return Air Ducts Often Foster Mold and Mildew

HVAC, ventilation
An 1892 drawing of mold

We know, kids aren’t the best at collecting their dirty laundry and putting it in the hamper where it belongs. Nevertheless, before you blame Junior for the musty smell that is permeating your living space, consider your return air ducts, and the nooks and crannies inside the rest of your home.

First, it should go without saying but we’ll say it anyway: mold and mildew are dangerous. These fungi have been demonstrated to cause or aggravate headaches, allergy symptoms and even respiratory diseases over the long term. Very young children and the elderly can suffer particularly nasty symptoms, so if you can smell it within your home, it’s time to get help, immediately.

Find the Source

It starts with a little detective work. Leaky roofs and walls can let moisture in through loose joints or ductwork cracks, which in turn can spread to your return air ducts. Even worse? If moisture reaches your insulation covering the ducts, it can spawn even more fungus growth, and bad smells.

Condensate drains should also be checked. They are designed to bring water away from your air handler to the outside, but a blockage could result in moisture seeping into ductwork instead. More moisture equals more mold, and the awful smell.

Evaporator coils can be a problem. If excess moisture forms on the coils, the airflow over them will blow mold and mildew into your ductwork too. Fans can create similar excess moisture, if set incorrectly, as can clogged filters.

Clean The Ducts

We’ve talked in this space before about ductwork cleaning scams, but in this case, true mold and mildew should be removed by a professional (who also should address its cause). Abatement is a serious issue. Done improperly, it can result in disastrous consequences, not only for your family, but your pocketbook. If you smell something icky, don’t blame your teenager (yet). Call a licensed HVAC professional for a consultation first.


Musty rooms? Don’t wait until serious health problems or property damage develop. Call Air-Tro today. (626) 357-3535