Duct Sealing - In houses with forced-air heating and cooling systems, ducts are used to distribute conditioned air throughout the house. In a typical house, however, about 20 to 30 percent of the air that moves through the duct system is lost due to leaks, holes, and poorly connected ducts.
Air Sealing - The EPA estimates that between 25 and 30 percent of the energy that we use to heat and cool our homes is lost due to the air leaks through the attic, the basement, and other places in a house. Small air leaks into uninsulated attic space are a major source of heat loss in many homes. ... These gaps around plumbing pipes, light fixtures, chimneys and other attic bypasses are hidden under your insulation. ... Warm air flows out through tiny gaps in the ceiling and walls, resulting in higher energy cost.