What is air sealing and why is it important?
Air sealing is simply closing holes, cracks, and gaps where air can pass
into or out of your home. On hot and cold days, you pay money to run an
air conditioner or a furnace
to maintain your home at a comfortable
temperature. A house that leaks air costs more to be heated or cooled,
because your system must work longer to "condition" the air. In
addition, if you happen to sit next to one of those leaks, you are
uncomfortable because the room may feel hotter or colder due to drafts.
Sealing the air leaks will help you maintain your home at a comfortable
temperature all year long and help lower energy bills.
The biggest holes are most often found in the attic and the basement.
Caulk, spray foam,
weather stripping and insulation are the most common
materials used for air sealing. The
top picture shows an open duct chase in the attic. This chase allows
unconditioned attic air into the home and possibly the duct work.
The bottom picture show the solution, sealing the chase with foam and
rigid board.
Ventilation is fresh air that enters a home in a controlled manner to
exhaust excess moisture and reduce odors and stuffiness. Air leakage, or
infiltration, is outside air that enters a house uncontrollably through
cracks and openings. It is unwise to rely on air leakage for
ventilation. During cold or windy weather, too much air may enter the
home and, during warm or calm weather, too little. Also, a "leaky" home
that allows inner wall or attic air to enter is not healthy. The
recommended strategy in both new and older homes is to reduce air
leakage as much as possible and to provide controlled ventilation as
needed.
The insulation, outer walls, ceiling, doors, windows, and floors all work together to control airflow in and out of the structure, repel moisture, and prevent heat from being lost or gained inside your home.