Why Are My Ducts Sweating?

Why Are My Ducts Sweating?

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Temperatures tend to be relatively warm here in the El Dorado Hills area, and you can probably recall several occasions when the summer heat has made you sweat. Sweating may be healthy and natural in people, but what about the air ducts in your home? Condensation on your ductwork is a bad sign, indicating that you have a larger HVAC issue on your hands. If you have sweating ductwork, it’s important to pinpoint the underlying cause and to resolve the situation as soon as possible.

What’s Causing Your Ducts to Sweat

Don’t blame your HVAC system just yet. Sweating ducts are usually an indication that your home is not properly air sealed and insulated. Why?

When your home is poorly sealed and under-insulated, outdoor air is allowed to enter. During the summer, this hot and humid air eventually comes into contact with the cold surface of your AC ducts, causing it to release moisture (because cold air cannot hold as much moisture as warm air). While during the winter, the cold air from the outdoors can condense on your warm ducts. This moisture settles there, making your ductwork look like it’s sweating.

The Dangers of Condensation on Ductwork

Condensation on ductwork doesn’t just indicate that you have an air sealing or insulation problem; the condensation itself can contribute to a number of other issues in your home. Sweating ducts can eventually cause mold and mildew growth, water damaged insulation, and moisture issues on nearby ceilings and walls. These issues, in turn, can impair your home’s indoor air quality, decrease home energy efficiency, and even undermine the very integrity of your home’s structure, putting you and your family at risk.

The Best Solutions for Sweating Air Ducts

Because sweating ducts usually indicate that you have air leakage and insulation gaps in your home, the first step to resolving the issue is to make sure your home is properly sealed and insulated. This is especially important in the areas that hold your ductwork. An energy audit can help you determine exactly which areas of your home need to be sealed and insulated.


Once you have completed proper air sealing and insulation, duct sealing can further help resolve the issue by eliminating points of air leakage in your ductwork. It’s also a good idea to have your ductwork insulated to prevent condensation from forming along the surface of your ducts.

Do you have condensation on your air ducts? Contact us or call (916) 737-1107 today to solve the problem once and for all!