Air leakage is a major energy waster in many homes. Unfortunately, there are some myths that are commonly passed along about air sealing measures that just don't hold up.
MYTH: Duct tape is good for sealing ducts.
TRUTH: Unfortunately, laboratory research has concluded that duct tape has very low durability when used to seal ducts. On new installations, tape often falls off due to poor surface preparation, because ducts tend to be installed in dirty and dusty locations and conditions. On older systems, the tape falls off as it ages and the adhesive dries out and wrinkles. Instead of duct tape, seal ducts with mastic.
MYTH: Installing foam gaskets in electrical outlets will significantly reduce air leakage.
TRUTH: Measurements have shown that less than 1% of a home's air leakage is due to outlets. However, a lot of little holes add up to one big hole. If you’re doing a thorough air sealing job, or you’re in a very big house with a lot of light switches, it wouldn’t hurt to install gaskets—but you might want to save this measure for last, in case you run out of time or energy.