Fibrous glass duct liner insulation is designed for application to the interiors of commercial and residential sheet metal heating, ventilating, and air-conditioning ducts to attenuate noise generated by central air handling equipment, air movement within the ducts, and occupant cross-talk. It also serves to reduce heat loss or gain through sheet metal duct surfaces, and helps to prevent the formation of water vapor condensation both inside the duct and on its exterior surface. Fibrous glass duct liner insulation is fabricated along with the sheet metal work in the shop, providing quality workmanship under controlled conditions.

Fibrous glass duct liner insulations are manufactured from glass fibers bonded with thermosetting resin. They are dimensionally stable, withstand abuse, and provide a cleanable, fire-resistant interior surface designed to minimize friction loss. Two forms are available:

1. Flexible blankets, supplied in roll form;
2. Rigid boards, supplied in sheet form.

Fibrous glass duct liners are manufactured to comply with ASTM C 1071, Standard Specification for Fibrous Glass Lining Insulation (Thermal and Sound Absorbing Material). These products are available with coated or faced airstream surfaces.