Duct Leakage in Your Crawl Space

If you have air ducts in your crawl space (which most do), then you have a built-in air highway to efficiently mix all the air in your home—from your crawl space to the upper levels.  How does this happen?  It’s simple—duct leakage.

Air ducts are made up of several segments of sheet metal.  Between each section and at the elbows there are joints, which are simply bent, crimped, or screwed together.  Air ducts are constantly under a large amount of pressure from blowing the air to try to heat and cool your home. 

As the pressurized air passes by loose joints and seams in the ducts, a little bit of air leaks out.  Even if it’s only 2% of the air in the duct that leaks out each time, it really adds up.  If 2% of air leaks out at every joint of the duct, that’s a lot of duct leakage.

This costs you even more money to heat and cool your home.  It also depressurizes the living spaces above, meaning the damp and moldy air from the crawl space gets pushed up into the living spaces faster than it normally would.  Duct leakage is a no win situation.