Three-Sided Angle Installation for Greenheck Fire and Combination Fire Smoke Dampers
January, 2019

Greenheck has developed a UL-approved three-sided retaining angle installation method for fire and combination fire smoke dampers. This method is ideal for installations where the damper sleeve is tight up against a wall, floor, or other obstruction with no room for a retaining angle on one side. Greenheck’s installation does not require the use of any Greenheck-Damper-Three-Sided-Angle-Installation-imagefirestop material, while other three-sided angle installation methods require fire stop material to be applied to a specified minimum thickness on the side of the damper without the retaining angle. Complying with the minimum thickness requirement without scraping off the fire stop material during installation can be difficult, and makes it complicated for building inspectors to confirm that the required amount of fire stop material has been applied. With Greenheck’s three-sided angle installation method, fasteners are run from inside the damper into the wall opening on the side without the retaining angle. This makes for a faster, cleaner and more cost effective installation.

Greenheck, the worldwide leader in manufacturing and distributing air movement, conditioning and control equipment, offers the most UL certified dampers and the largest selection of AMCA licensed dampers in the industry.

For more information about Greenheck products, visit or contact Greenheck, P.O. Box 410, Schofield, WI 54476-0410, (715) 359-6171, FAX (715) 355-2399.