Sealing Duct Work Saves Energy

If a home’s utility bills seem to be a little high you may want to look into the seals of the duct work in a forced air heating and cooling system. The duct work is usually located in the basement rafters, in the attic or in a crawl space under the home or even in the garage and if the joints are not sealed properly can cause air loss. In addition to higher utility bills this will also result in the heating and cooling system having trouble keeping up with demand, regardless of what the temperature is set at.

Sealing duct work is something homeowners can do on their own without the need to call in a heating and air contractor and although it can be a little messy it really isn’t that difficult. All you need is some old clothes, a caulking gun and a product called Mastic that you apply like paint just a little thicker.

Start at the air distribution ducts. These are the largest ducts that are attached to the main air outlet of the furnace. Using the Mastic and a paint brush, apply the material to the joints of the duct and where it meets the furnace, ensuring an even coating. Continue up the duct, applying Mastic to the corner joints in the duct. Continue to apply Mastic to the ducts that run from the main duct throughout the rest of the house that can be accessed.

If your home has flexible duct work that extends from the main duct, carefully remove it. Usually it is held in place by a metal band secured by a single screw. Unfasten the band and pull the flexible duct from the collar. Using the Mastic as paint, or in a tube that fits into your caulking gun, seal the portion of the collar where it is attached to the main duct.

If you have air vents dropping out of the main duct into the room through which the duct runs, remove the vent and apply a coat of Mastic around the cut-out through which the vent goes. When you replace the vents and the flexible ducts to the main duct, be sure that everything is securely fastened to prevent them from working loose.

When your system was installed, the heating and air contractor likely sealed all of the ducts in the home, but if you are feeling the effects as described it won’t hurt to take a look at the duct work. Sealing the duct work in your home will add to the home’s comfort by providing more air flow to rooms that may be too hot in the summer or cold in the winter.

It will also improve air quality by keeping out dust and other particles that may work their way into unsealed ducts and work their way into the system and to most other areas of the home. It will also improve safety in the home. Consider other appliances like the hot water tank and clothes dryer when working may release gases into the air. Unsealed duct work may allow those gases to spread to other parts of the home. Homeowners unsure about the proper way to seal their duct work should contact their heating and air contractor to ensure it is done correctly.

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Living Well Now profile image

Living Well Now 4 years ago from Near Indianapolis

Great idea for the do-it-yourself folks. Do it now before the heating season. An informative hub.


Better Yourself profile image

Better Yourself 4 years ago from North Carolina Author

Thank you for taking the time - so glad it was helpful!

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