What Insulation Material to Seal Ceiling Vents

Metal Tape

• Metal reinforced tape is a conventional and low-cost material to use to seal ducts. However, tape can be somewhat tricky to use and manipulate if you don’t want the tape to show on the ceiling surface. You will need to take off the vent plate and examine the ductwork for gaps and crevices. Then use the tape to seal off the gaps and reattach the vent plate to the wall.

Mastic

• Mastic is another low-cost option for sealing vents on ceilings. Mastic is a thick, rubbery adhesive-like material that you apply with a brush. You paint on the mastic to fill large holes, gaps and crevices. You can also cut pieces of sheet metal to cover large holes and then seal the sheet metal with mastic.

Aeroseal

• The Aeroseal system uses some of the latest advances in technology for sealing vents and ducts. The system, which was developed at Lawrence Berkeley Laboratories under funding by the Department of Energy and the Environmental Protection Agency, is now made available to consumers through the Carrier Corporation. The system uses adhesive vinyl polymer particles to seal leaks inside ceiling vents and other areas of the home, if desired. The particles, which measure from two to twenty micrometers, are injected into the duct system behind the vents. A licensed technician must perform the application. The technician uses a special computer system that allows the homeowner to watch the application and the leaks being sealed in real time on a computer monitor. According to Lawrence Berkley Laboratories, the Aeroseal system is effective at sealing between 70 to 90 percent of all leaks in vents and ducts, making it one of the most effective energy conservation options on the market today. Aeroseal applications are guaranteed to last up to ten years. Costs vary, depending on the number of vents and ducts that will be sealed.

Underwriters Laboratory-Rated Materials

• If you use mastic or metal tape, always use a product that bears the Underwriters Laboratory label. Look for the number “181” on the product. This will assure you that the product has been UL tested and the adhesives meet standards recommended for sealing vents. Do not use common duct tape. It is not made to UL specifications and the adhesive will disintegrate from the heat that flows through the ceiling vents.

Considerations

• Check with your local gas and electric utility company to see if they offer any rebates or programs to offset the costs for ceiling your vents. For example, Pacific Gas & Electric in California, offers residential customers up to $200 in rebates for duct sealing projects. Consider getting an estimate on using Aeroseal for your ceiling vents and your entire home. According to estimates by the U.S. Department of Energy, homeowners can save as much as $600 per year on heating and cooling bills by using the Aeroseal system, as of November 2011.