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 percent of the air that moves through the duct system is lost due to
leaks and poorly sealed connections. The result is higher utility bills and
difficulty keeping the house comfortable, no matter how the thermostat is set.
Because some ducts are concealed in walls and between floors, repairing them can
be difficult. However, exposed ducts in attics, basements, crawlspaces, and
garages can be repaired by sealing the leaks with duct sealant (also called duct
mastic). In addition, insulating ducts that run through spaces that get hot in
summer or cold in winter (like-attics garages, or-crawlspaces) can save
significant energy: A duct system that is well-designed and properly sealed can
make your home more comfortable, energy efficient, and safer. Sealing and
insulating ducts can help with common comfort problems, such as rooms that are
too hot in the summer or too cold in the winter.
Indoor Air Quality
Fumes from household and garden chemicals, insulation particles, and dust can
enter your duct system, aggravating asthma and allergy problems. Sealing ducts
can help improve indoor air quality by reducing the risk of pollutants entering
ducts and circulating through your home. Safety During normal operation, gas
appliances such as water heaters, clothes dryers, and furnaces release
combustion gases (like carbon monoxide) through their ventilation systems. Leaky
ductwork in your heating and cooling system may cause "back drafting," where
these gases are drawn back into the living space, rather than expelled to the
outdoors. Sealing leaks can minimize this risk.
Leaky ducts can reduce heating and cooling system efficiency by as much as 20
percent. Sealing and insulating ducts increases efficiency, lowers your energy
bills, and can often pay for itself in energy savings. Plus, if you're planning
to install new heating and cooling equipment, a well-designed and sealed duct
system may allow you to downsize to a smaller, less costly heating and cooling
system that will provide better dehumidification.
Protect the Environment
Energy used in our homes often comes from the burning of fossil fuels at power
plants, which contributes to smog, acid rain, and global warming. Simply put,
the less energy we use in our homes, the less air pollution we generate. By
sealing your ducts and reducing the amount of energy necessary to comfortably
heat or cool your home, you can reduce the amount of air pollution generated.