Should You Seal Your Ducts?
A duct system that is properly sealed and insulated can make your home more comfortable, energy efficient and safer. So says Energy Star®, a program of the U.S. Environmental Protection Agency. And that’s just one part of the advice offered by the government-backed program. More specifically, Energy Star says 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.
Who Should Do This Kind of Work?
Heating and cooling equipment contractors are among the types of professional contractors who repair ductwork. When calling a professional, Energy Star advises homeowners to look for a contractor who will:
- 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 grilles 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.