GLASSCLOTH INSULATION FOR DUMMIES

UL Style and design 563 = Optional ceiling damper (confer with manufacturer for info on this type of damper).Duct connections to flanges of air distribution system devices or sheet metal fittings shall be mechanically fixed. Mechanical fasteners to be used with flexible nonmetallic air ducts shall adjust to UL 181B and shall be marked 181B-C. Crimp