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.
REDUCED AIR LEAKAGE
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.