home duct

Your home’s duct system may be wasting a lot of your energy dollars. The duct system is a branching network of tubes in the walls, floors, and ceilings. The duct system carries the air from your home’s furnace and central air conditioner to each room. Ducts are made of sheet metal, fiber glass, or other materials.

Many duct systems are poorly insulated or not insulated properly. Ducts that are poorly insulated can leak heated air into unheated spaces and 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.

Importance of sealing your ducts

Sealing your ducts to prevent leaks is important, especially 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 unsealed joints and lost. 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.

Although minor duct repairs are easy to do, ducts in unconditioned spaces should be sealed and insulated by qualified professionals using the appropriate sealing materials. .

Simple tips to help with minor duct repairs:

  • Check your ducts for air leaks.
    • Look for sections that should be joined but have separated.
    • Look for obvious holes.
  • If you use tape to seal your ducts, avoid cloth-backed, rubber adhesive duct tape, which tends to fail quickly.
    • Researchers recommend other products to seal ducts: mastic, butyl tape, foil tape, or other heat approved tapes. Look for tape with the Underwriters Laboratories logo.
  • Insulating ducts in the basement will make the basement colder.
    • If both the ducts and the basement walls are uninsulated, consider insulating both.
  • Be sure a well-sealed vapor barrier exists on the outside of the insulation on cooling ducts to prevent moisture buildup.
  • When doing ductwork, be sure to get professional help.
    • Changes and repairs to a duct system should always be performed by a qualified professional.
  • Ducts that don’t work properly can create serious, life-threatening carbon monoxide problems in the home.
    • Install a carbon monoxide monitor to alert you to harmful carbon monoxide levels if you have a fuel-burning furnace, stove or other appliance, or an attached garage.
  • For new construction, consider placing ducts in space that is heated and cooled instead of running ducts areas like the crawlspace or attic.

If you are buying a new duct system, consider one that comes with insulation already installed.