What is the best way to seal the leaks?
It is best to have a licensed heating and air conditioning contractor repair your system’s duct leaks. Return duct leaks are difficult to detect because the larger return ducts operate at a lower air pressure and air is being drawn into the system. And if you only repair the supply duct leaks, even more unconditioned air may be drawn into the system. Supply duct leaks are more easily noticed because you can feel air blowing out at the connections or see nearby insulation moving. Duct leaks can be sealed using mastic or acrylic-adhesive foil tape. Mastic adheres well to most surfaces and provides an effective long-term seal. Mastic alone may be used to seal cracks less than ΒΌ” wide. Foil tape carries a 20-year guarantee if applied properly. Any sealant should carry the Underwriters Laboratories rating (UL-181) specific for that particular type of duct. Most duct manufacturers are now listing the closure products that they allow to be used with their ducts. If you see the contractor brin
