Even if its walls and roof are insulated, your house may be losing energy--through its heating and cooling ducts.
Here are some insulating tips for making duct systems more enery-efficient, from Bob Vila of PBS's "This Old House" program, and Owens-Corning Fiberglas Corp., Toledo, Ohio.
Locate ducts and tape all sheet metal joints tightly with aluminum pressure-sensitive tape so conditioned air won't leak out.
Wrap ducts with 2-inch glass fiber duct wrap insulation, using large shears, a tape measure, pen, straight edge, and tape, as follows:
--Mark off on the wrap facing a length equal to the duct's perimeter plus 8 inches if duct is rectangular (12 inches if round). Cut wrap along this line, removing 2 inches of glass fiber at one end to leave a flap of facing.