General Construction Specifications
PART 1 - GENERAL
01 WORK INCLUDED
A. Provide internal ductliner for sound attenuation and thermal insulation as required by this section and the drawings.
PART 2 - PRODUCTS
02 MANUFACTURERS
A. Provide products as manufactured by Certainteed, Knauf, or Owens-Corning.
03 FIBERGLASS DUCT LINER
A. Fiberglass duct liner shall be manufactured from heavy density, continuous long fiber inorganic glass fibers bonded by a thermosetting resin. Liner shall be rigid 3 lb./cubic foot density with a thermal conductivity of 0.23 at 75oF mean temperature.
B. Duct liner shall have an air stream side coating of non-eroding black neoprene.
C. Internal duct liner shall have a noise reduction coefficient of 0.75 when tested in accordance with ASTM C-423-77.
D. Duct liner shall be suitable for duct velocities up to 4000 feet per minute and maximum airstream temperatures up to 250oF.
E. Internal duct liner shall have a maximum flame spread rating of 25 or less, a smoke developed rating of 50 or less, and a fuel contributed rating of 50 or less when tested in accordance with ASTM E-84 and UL 723 procedures.
04 ADHESIVE
A. Adhesive used to adhere the lining material to the sheet metal and to coat edges shall comply with "Standard for Adhesives for Duct Liner", ASC-A-7001C (latest edition) by the Adhesive and Sealant Council, Inc.
05 MECHANICAL FASTENERS
A. Fasteners used to secure duct liner shall be weld on stick pins and clips conforming to the latest edition of "Mechanical Fastener Standard", SMACNA Standard MF-1.
PART 3 - EXECUTION
06 INSTALLATION
A. Install internal duct liner in accordance with manufacturer's recommendations.
B. Duct liner shall be cut to assure overlapped and compressed longitudinal corner joints.
C. Duct liner shall be adhered to sheet metal with 100% adhesive coverage.
D. Liner shall be additionally secured with mechanical fasteners at 16" centers maximum. Fasteners shall start within 3" of upstream transverse edges and 3" from longitudinal joints. Fasteners shall be placed at a maximum of 6" centers around perimeter of duct.
E. Coat transverse joints and longitudinal joints with adhesive.
07 APPLICATIONS
A. Provide 1" thick duct liner for the following applications:
1. Medium pressure supply air duct from fan discharge to final filter inlet.
2. Low pressure supply duct for a distance of 10 feet downstream of VAV (or fan powered VAV) box discharge.
3. Return air duct in mechanical rooms and as indicated on drawings.
4. Outside air ducts and plenums in mechanical rooms.
5. Mixed air plenums and casing plenums.
B. Where internal duct liner is installed maintain inside clear dimensions as shown on drawings.
END OF SECTION
