How to Prevent Moisture in Air Ducts

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Large ductwork with mastic sealant on concrete ceiling

The Air Ducts Explains: How to Prevent Moisture in Air Ducts

Winter is in full effect, and homeowners will rely on their furnaces to provide warmth and comfort. Since AC ducts are not used during the offseason, the unconditioned spaces can become drenched with condensation if you do not take certain precautions. Large amounts of water that accumulate in your air ducts can eventually cause serious problems in your home. Today, Air Duct Cleaning explains the causes of moisture in air ducts, and we provide some tips for preventing condensation.

What Causes Moisture in Air Ducts?

Condensation can develop on the outside and inside of ducts. In the summer, high levels of humidity can result in condensation. In the winter, warm air encounters the cool surface temperature of your air ducts and condensation forms. Other causes of moisture in air ducts include poor insulation, dirty air filters, and excess moisture in the air.  

When a collection of water meets existing dirt or dust in an air duct, mold growth can occur. Sustained mold growth happens when condensation creates wet conditions. If you notice small stains on your walls or ceilings, or bad smells coming from your vents, ductwork condensation could be the issue. 

How Can I Prevent Moisture in Air Ducts?

There are a few steps you can take to avoid a surplus of duct condensation. 

Look for any Sources of Moisture

Water pipe leaks or roof leaks could be sources of moisture. Check the pipes, clothes-dryer vent, bathroom and kitchen vents, and the furnace venting system for any leaks. If one of these systems is leaking, this could be causing the issue. 

Use a Dehumidifier

After you confirm that the above systems are working properly, use a dehumidifier where your air ducts have been collecting water. This electrical appliance removes humidity from the air, which will reduce moisture and prevent condensation in ductwork. 


Lastly, make sure your ductwork is well insulated. Adding insulation will prevent the ducts from condensation in the warm or cool air that flows through. If you plan on putting in new insulation, Air Duct Cleaning can safely remove your old material. Contact us for more information about insulation removal.

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