Business Description: Northern Duct Seal seals duct work from the inside by use of computerized tools and equipment. The process takes one day and our technicians will provide pre-seal and post-seal duct leakage reports on the spot. The basic steps to do a duct seal are: 1) Pre-seal Test is done to measure duct leakage, 2) Registers, returns, and air handler coil are blocked off with foam plugs, 3) A UL-tested and approved aerosol is injected into the pressurized duct system, 4) A Post-Seal Test is performed to measure improvements and 5) A complete Report and Certificate are printed to provide the customer with a record of improvement. Duct sealing provides a solution to high energy bills, air flow/air balance issues, uneven temperatures, hot and cold rooms, excessive humidity, musty odors and fume smells from stored paints, solvents, pesticides, and radon gases. Northern Duct Seal will reduce duct leakage by up to 90%, saving customers an average of $600 - $850 a year, with a 2-3 year return investment, depending on variables such as weather, system usage, energy prices, and home design. Northern Duct Seal offers a 10- year warranty on the seals created by our technicians. The sealant itself has been UL tested and approved and is considered non toxic by OSHA. For a demonstration video of the duct sealing process please see the 'Ask This Old House' Video located under the Media tab on this page.