Tuesday, August 15, 2006

Ductwork Efficiency

Improving the efficiency of ductwork is the single most important energy measure for most affordable homes. Poor ductwork can waste hundreds of dollars each year and cause serious health and safety problems. It is best to locate ducts inside the living area-not in attics or crawl spaces. Do not use building cavities, such as closet returns, as part of the duct system. Make sure all joints in the ductwork are sealed permanently with mastic; duct tape and insulation do not provide an effective seal. After ducts are sealed, ensure that they have adequate insulation. The Model Energy Code sets minimum requirements, but higher levels are often cost effective.

Excess air leakage in homes can increase heating and cooling bills by 30 percent. Although windows, doors, and outside walls contribute to air leakage, the biggest holes are usually hidden from view and connect the house to the attic, crawl space, or basement. Reducing air leakage typically costs less than $200 for the average home.

A family of four can spend more for hot water than heating or cooling. Simple conservation measures, such as low-flow showerheads, tank insulation jackets, and convection traps in hot and cold water lines, pay back quickly.


pk said...

Anthony - very useful post. How can one deduct the air leakage?

Anthony said...

Air leakage can be determined by using a special fan called a blower door that forces air into (or out) of a home. A special gauge is able to read the "leakiness" of the home. (Yup, you may want to use a professional to do this job). What areas leak the most? Of course most people would figure the cracks around the exterior doors and windows. But air could also leak out of the ductwork and vents leading into your furnace. Leaky ductwork means not all the heated/cooled air is reaching the living spaces of your home. Thanks for the question, hope it helps!!