9 Steps to Seal the Inside of Your Ductwork

November 20, 2020

You already know that sealing your ducts saves money on utility costs and protects the lifespan of your HVAC system. Once you realize your ductwork needs to be sealed, you may wonder how to go about the job. The traditional way to seal ducts is to apply a special metal tape or sealant to the exterior, yet this can be challenging and time-consuming with unpredictable results. Sealing the interior of ductwork is a new innovation that simplifies the process and ensures a good, energy-saving outcome. Here are nine steps to follow when sealing the inside of the ductwork in your home.

1. Gather Materials

First, you need to gather the materials needed for sealing your ductwork, including:

  • Aerosol sealant product and sprayer
  • Blower fan
  • Foam rubber
  • Wide tape
  • Tool to run a pressurized blower test

2. Remove Vent Covers

Remove the covers from the supply and return vents of your heating system. This gives you access to the ductwork for cleaning and sealing.

3. Clean the Ducts

Aerosol products that are used to seal ductwork from the inside need to adhere properly to the metal walls. You should begin this project by cleaning the duct and removing any dust, dirt, debris, and pet dander that clumps inside the ducts. Take your time on this step. The better you clean your ducts, the better the aerosol product will work.

4. Cover Vent Openings

After the ducts have been thoroughly cleaned, you need to cover the openings for the pressure test. Use foam rubber and wide tape to close off the openings.

5. Pressurize the Ducts

Once the vent openings are sealed, you need to run a pressure test. Use the blower fan to add air to the ductwork. Because the vents are closed off, the pressure inside the vents increases.

6. Calculate Air Loss

Use a computer to measure the pressure inside the vents. If there are any leaks in the ductwork, you will see the pressure decrease gradually. This is a sign that the ducts have holes and other damage that allows heated air to escape.

7. Apply Aerosol Sealer

Follow the directions on the aerosol sealer to apply a thin layer of rubber sealant inside the ductwork. Be sure to cover all sides of the ductwork completely. Take your time, and be sure not to apply too much of the sealants and cause lumps or an uneven surface. Any irregularities will disrupt airflow, and your system will work harder to keep the inside of your home comfortable. An irregular surface is also more likely to erode over time, and you may need to re-seal your ducts in the future.

8. Recheck for Air Leaks

After you apply the first coat of aerosol sealer to your ductwork, run the pressure test a second time. Again, give the computer time to detect changes in air pressure. If the reading on the computer is constant, you have successfully sealed all of the holes and openings. If the pressure drops, you still have holes in the ducts.

9. Apply More Aerosol Sealant If Needed

Apply a second coat of aerosol sealant to the entire interior of your ductwork. As with the first coat, make sure that the product is even and smooth. Move the sprayer using a constant and continuous motion. Clumping and uneven application are more likely with subsequent applications. Re-check the pressure to see if all the holes have been sealed, and apply more product as needed.

Easiest Way to Seal Ductwork from the Inside

Sealing ductwork from the inside is a complicated and time-consuming process if you have not done it before. Fortunately, there’s an easier way. The expert HVAC technicians at Hunter's Air & Heat, Inc. are well-versed in sealing ductwork from the inside, and they have helped many homeowners like you in Wharton and surrounding areas. They complete the job quickly and efficiently, so you can start saving money on utility costs right away.

Hire a Professional to Seal the Inside of Your Ductwork

If you live in Wharton or a nearby community, Hunter's Air & Heat, Inc. is your expert HVAC company for all of your needs. In addition to sealing the interior of your ductwork, we can also help with your heating and air conditioning installations, maintenance, and repairs. Hunter's Air & Heat, Inc. also specializes in attic insulation solutions and indoor air quality products. Call us to learn more so we can schedule an appointment with one of our expert technicians.

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