Fibrous glass has been used as thermal and acoustical insulation in forced air heating, ventilating, and air- conditioning systems ever since these systems became widely available following World War II. Today, fibrous glass duct systems, duct liners, duct wraps, and commercial insulation boards contribute to indoor environmental quality (IEQ) and occupant comfort in residential, commercial, industrial, and public buildings of all kinds. These include homes, apartments, schools, hotels, motels, medical facilities, theaters, shopping centers, office and government buildings, factories, and many other types of structures where occupant comfort and indoor environmental quality are important criteria.
Fibrous glass insulation is used in air duct systems for four basic reasons:
HVAC systems typically operate with internal air temperatures between 40˚F (4˚C) and 250˚F (121˚C). Systems operating outside this range are not considered in this guide, except that fibrous glass insulation boards may be used in systems operating at internal air temperatures between 0˚F (-18˚C) and 450˚F (232˚C).