EPA Duct Sealing Guidelines
January 30, 2024
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 to 30 percent of the air that moves through the duct system is lost due to leaks, holes, and poorly connected ducts. The result is higher utility bills and difficulty keeping the house comfortable, no matter how the thermostat is set.
How do you know that your home has poorly performing ducts?
- you have high summer and winter utility bills;
- you have rooms that are difficult to heat and cool;
- you have stuffy rooms that never seem to feel comfortable;
- your ducts are located in an attic, crawlspace, or the garage;
- you find tangled or kinked flexible ducts in your system.
Benefits of Duct Sealing
A duct system that is well-designed and properly sealed can make your home more comfortable, energy efficient, and safer.
Learn more about the Benefits of Duct Sealing.
Simple Steps to Improving Duct Performance
Because ducts are often concealed in walls, ceiling, attics, and basements, repairing them can be difficult. But there are things that you can do to improve duct performance in your house.
Some homeowners choose to take on duct sealing as a do-it-yourself project. Start by sealing air leaks using mastic sealant or metal tape and insulating all the ducts that you can access (such as those in attics, crawlspaces, unfinished basements, and garages). Never use duct tape, as it is not long-lasting. Also, make sure that the connections at vents and registers are well-sealed where they meet the floors, walls, and ceiling. These are common locations to find leaks and disconnected ductwork.
Many homeowners choose to work with a professional contractor for duct improvement projects. Most heating and cooling equipment contractors also repair ductwork.
- View our Duct Sealing Fact Sheet (PDF, 787 KB) to learn more.
- View Frequently Asked Questions about Duct Sealing.