GLASSCLOTH INSULATION FOR DUMMIES

UL Design 563 = Optional ceiling damper (refer to company for info on this kind of damper).Duct connections to flanges of air distribution program machines or sheet steel fittings shall be mechanically fastened. Mechanical fasteners to be used with flexible nonmetallic air ducts shall comply with UL 181B and shall be marked 181B-C. Crimp joints for