Duct Sealing



• Inspect the whole duct system, including the attic, crawlspace, garage and basement as needed.

• Evaluate the system’s supply and return air balance.  Many systems have air return ducts that are too small.

• Repair damaged and disconnected ducts and straighten out flexible ducts that are tangled or crushed.

• Seal all leaks and connections with mastic, metal tape, or an aerosol-based sealant.

• Seal all registers and grills tightly to the ducts.

• Insulate ducts in unconditioned areas with duct insulation that carries an R-value of 6 or higher.

• Include a new filter as part of any duct system improvement.

• Evaluate air flow after repairs are completed.

• Ensure there is no backdrafting of gas or oil-burning appliances, and conduct a combustion safety test after ducts are sealed.


A duct system that is properly sealed and insulated can make
your home more comfortable, energy efficient, and safer.  Making improvements to your duct system can:

Improve Comfort

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.

Enhance 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.

Promote Safety

During normal operation, gas appliances such as water heaters, clothes dryers, and furnaces release combustion gases (like carbon monoxide) through their venting systems.  Leaky ductwork in your heating and cooling system may cause “backdrafting,” where these gases are drawn back into the living space, rather than expelled to the outdoors. Sealing leaks can reduce this risk.

Save Money

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

When power plants burn fossil fuels to make electricity, they release greenhouse gases. By sealing ductwork and using less energy at home, you can help reduce these emissions and fight global warming.


Duct Cleaning Services, Terre Haute, Brazil, Indiana