Asbestos in Heating Ducts Explained
Heating ducts in residential and commercial buildings may result in dangerous asbestos exposure from many different sources.
For years, lagging cloth and asbestos paper was used by the HVAC industry to line and insulate pipes in heating and cooling systems within homes, offices, and other buildings.
Paper, cloth, and other insulation materials are often used to repair potential weaknesses in the heating ducts and reinforce the overall system.
For example, an adhesive is applied to any area along the duct system that is experiencing, or could encounter, an outflow of air, and may then be wrapped with insulating cloth or paper.
In some cases, duct dampeners are used to reduce vibration and secure flexible joints.
Asbestos in HVAC Insulation
In the prime of asbestos use, lagging cloth, duct dampeners, and other duct wrappings usually contained asbestos fibers.
Insulation manufacturers used asbestos because it was inexpensive and had many desirable properties. Asbestos is durable, heat- and fire-resilient, easy to use, and has superb soundproofing qualities.
Asbestos was considered an excellent component for insulation. As a result, asbestos-containing cloth and pipe wrapping paper were used in many heating and cooling systems built or installed prior to the 1980s.
Today, North American lagging cloth brands no longer contain asbestos. However, many homes built or renovated before the 1980s will still have lagging cloth, dampeners, or asbestos paper that contains asbestos.