Standard Sizes
Standard round gravity ventilators are available in 12”, 20” and 24” diameter throat sizes.
Integral Dampers
The damper is supported in the open position by four strong springs and is closed by a 5’ pull chain. Longer lengths are available upon request. Damper may be locked in any position by using the optional key type chain lock. Gravity ventilators may be furnished without damper if desired. However, overspray or driven rain may enter the vented space. Gravity vents with dampers may function as smoke exhaust vents by including a fusible link in the chain operator.
Construction
Aerodynamic design enhances the looks and performance of metal buildings’ architectural roof systems. Unit moves toward the ridge on floating roofs, and vents are made to match roof slope and maintain a low-profile appearance.
Bird Screen
Assembly requires the installation of a 4 x 4 bird screen in the opening, between the inner band and rain shield, to prevent birds from entering the vent area.
Finish
Galvalume finish is standard. Polar White and other colors — including Kynar® — are available.
Base Design
Base is specifically designed for final installation with specified roof slope — either ridge or single slope, and either flat or mounted into the specified roof panel. Base and ventilating unit arrive preassembled, ready for installation. Single-slope bases mount directly to the roof panel and are placed in such a way as to prevent damming.
Note: When ordering, please specify roof slope, base type, damper pull chain and paint color.
