scope:

A. The work covered by this specification consists of furnishing all labor, equipment, materials and accessories, and performing all operations required for correct fabrication and installation of commercial or residential air duct systems of sheet metal lined with fibrous glass duct liner in accordance with applicable project drawings and specifications, subject to terms and conditions of the contract:

1. All air duct systems operating at internal air velocities not exceeding rated duct liner limitations and internal air temperature not exceeding 250°F (121°C) nor below 40°F (4°C).

2. Duct liner products shall conform to the requirements of ASTM C 1071.

3. The manufacturer's product identification shall appear on the air stream surface.

4. Duct liner adhesive shall conform to the requirements of ASTM C 916.

5. The finished duct system shall meet the requirements of NFPA 90A and 90B including:

• It shall be rated for maximum operating temperature of 250°F (121°C) per ASTM C 411.

• It shall have a flame spread index not greater than 25 and a smoke developed index not greater than 50 per ASTM E 84 or CAN/ULC S102.

• It shall have a potential heat value not greater than 3,500 Btu/lb (8,141 kJ/kg) per NFPA 259.

• It shall have no microbial growth when tested per ASTM C 1338, ASTM G 21-96 (fungus test).

Marking on the airstream surface of the duct liner shall provide evidence of compliance.

B. Dimensions shown on the plans are finished inside dimensions.

C. Fabrication and installation shall conform to the manufacturer's recommendations and to the requirements of the latest edition of NAIMA FGDLS or SMACNA HVAC DCS.