Attics are not the only places where leakage can occur in homes, but leaks between the house and the attic are especially troublesome during the winter when warm air inside the home naturally tends to rise and flow out through leaks into the attic. This could lead to drafts (as colder outside air must be pulled in to offset the amount of air that flows up and out), condensation on the roof decking in the attic and high energy bills to heat the unconditioned air that leaks in. In the summer, poor comfort and indoor air quality can result as leaks from an attic allow hot, humid and dusty attic air to enter a home when exhaust appliances such
as kitchen or bathroom fans and clothes dryers operate. In some homes, powered attic ventilators, actually
waste considerable energy in the summer because they unintentionally pull conditioned air out from the house and up to cool the attic.