After ceilings, floors, and walls, ductwork can account for up to 15% of a home’s winter heat loss, according to the U.S. Department of Energy. This network of tubes in a home’s walls, floors, and ceilings distributes conditioned air to the rooms in your home. Most systems, unless they’re relatively new, are uninsulated or not insulated properly. And uninsulated and leaky ducts translate into energy dollars down the drain.
Insulating and sealing ducts is especially important if they are located in unconditioned spaces. In the wintertime, ducts can leak heat, and in the summertime, they can draw in hot air, decreasing your central air-conditioning system’s efficiency.
Minor duct repairs are easy to do yourself, but you may want to consult a pro to test, insulate, and seal ducts in unconditioned spaces. First look for sections that should be joined, but have separated, and then look for obvious holes. Seal your ducts with Underwriters Laboratories (UL) certified tape to ensure a long-lasting bond. Insulating ducts in a basement will make the basement colder in winter, so if both the ducts and the basement walls are uninsulated, consider insulating both. To help prevent condensation on cooling ducts, make sure there’s a well-sealed vapor barrier on the outside of the insulation. In most areas, use duct wrap insulation of R-4 or R-6.