Posted: March 9, 2015
According to the national Department of Energy, “Typical duct systems lose 25 to 40 percent of the heating or cooling energy put out by the central furnace, heat pump, or air conditioner. Homes with ducts in a protected area such as a basement or dropped ceilings may lose somewhat less than this, while some other types of systems (such as ducts in attics or underneath raised homes in our hot, humid climates) often lose more.”
Considering that 40 to 50% of our utility costs come from heating and cooling our homes, the loss of energy coming from duct leakage is substantial. For example, suppose that your annual utility costs were a conservative $1800.00 per year. About $810.00 of that (45%) would account for heating and cooling your home. 40% of that $810.00 is $324.00 per year that is being wasted on duct leakage. So what could you do with an extra $324.00 per year? I have a good idea of what you should spend it on this year….improving your air distribution system, what else?
Duct leakage not only costs homeowners money on utilities. It also causes other problems such as mold, mildew, indoor air quality problems, water stains around air vents, and general discomfort in the home. When the ducts are inside the attic, leaking ductwork pressurizes the attic and depressurizes the house, causing air infiltration from the attic space. Supply ducts that leak cold air into a hot humid attic reach dew point quickly and condensation can form. As the condensation collects, it gives way to mold and water stains on the sheetrock below. Not only is this a waste of money but contributes to lots of building performance issues. Leaky return ducts can also suck up insulation and dust fibers from the attic and distribute them throughout the house. This process also allows the indoor HVAC equipment to become dirty and inefficient. This is most noticeable to people who have allergies. Pay attention to the how often you dust your home. Most homes that are dusty have duct leakage and poorly installed air barriers between the house and attic space.
If you are experiencing any of these problems, call a professional, such as LaGrange Consulting, to perform a duct leakage test. This will diagnose the problem and pinpoint the leakage areas. After you have the test done, it’s time to improve your ductwork.