U.S. Department of Energy: Energy Efficiency and Renewable Energy

Energy Savers Tips

Site Navigation ↓

Ducts

One of the most important systems in your home, though it's hidden beneath your feet and over your head, may be wasting a lot of your energy dollars. Your home's duct system, a branching network of tubes in the walls, floors, and ceilings, carries the air from your home's furnace and central air conditioner to each room. Ducts are made of sheet metal, fiberglass, or other materials.

Unfortunately, many duct systems are poorly insulated or not insulated properly. Ducts that leak heated air into unheated spaces can add hundreds of dollars a year to your heating and cooling bills. Insulating ducts that are in unconditioned spaces is usually very cost effective. If you are buying a new duct system, consider one that comes with insulation already installed.

Sealing your ducts to prevent leaks is even more important if the ducts are located in an unconditioned area such as an attic or vented crawl space. If the supply ducts are leaking, heated or cooled air can be forced out of unsealed joints and lost. In addition, unconditioned air can be drawn into return ducts through unsealed joints. In the summer, hot attic air can be drawn in, increasing the load on the air conditioner. In the winter, your furnace will have to work longer to keep your house comfortable. Either way, your energy losses cost you money.

Although minor duct repairs are easy to make, ducts in unconditioned spaces should be sealed and insulated by qualified professionals using appropriate sealing materials. Here are a few simple tips to help with minor duct repairs.

Duct Tips

Image of ducts in an insulated attic. Hot air travels through the ducts into the room below. Some hot air is shown leaking out through the ducts into the attic.

Ducts—Out-of-Sight, Out-of-Mind
The unsealed ducts in your attic and crawlspaces lose air, and uninsulated ducts lose heat, wasting energy and money.

Long-Term Savings Tip

Back to Top | View Full Site
Energy Savers Tips Home | EERE Home
Webmaster | Search
Content Last Updated: 12/15/2008