SMACNA FIBROUS GLASS
FIBROUS GLASS DUCT CONSTRUCTION STANDARDS
|Publication Date:||1 June 2003|
MODEL PROJECT SPECIFICATION
Fibrous glass duct shall be of type (475) (800) and shall be of 1 in. (25 mm) or 1½ in. (38 mm) thickness and conform to the SMACNA Fibrous Glass Duct Construction Standards, 7th Edition, 2003 or the NAIMA Fibrous Glass Duct Construction Standards, 5th Edition, 2002. The fabricator shall submit for the approval of owner's representative or the approval of local mechanical code official the following:
a. The title of the standard the fabricator chooses to comply with;
b. A list of any deviations from the selected standard and the reason(s) therefore;
c. The name and product rating of manufacturer of the duct board;
d. The type of closures systems selected, along with confirmation that they are acceptable to the board manufacturer and are listed by U.L.
e. A schedule of duct pressure classifications and the air handling systems for which they are selected.
f. The type and spacing interval of supports selected;
Zinc coating weight for all galvanized steel sheet shall be G 60 or G 90.
Notice to Specifiers: The separate SMACNA and NAIMA standards were produced with different objectives. Although much of the construction detail is similar in the two manuals, there are significant differences. In some instances SMACNA has featured only methods that contractors would consider to be the most economical. In others, a conservative approach was taken to limit the number of alternatives in order to have fewer nuances with which to be concerned. Otherwise, having other qualified training resources precludes the need for comprehensive fabrication instructions. Discrediting the NAIMA approach to the scope of standards was not an objective. For fabrication with type 1400 board, see NAIMA standards.