Fantech 4" Back-Draft Damper for Circular Duct, Single

Backdraft Dampers are non-flanged horizontal mount exhaust backdraft damper. The frame is galvanized steel with aluminum blades. The blades have a felt seal on the leading edge for quiet closing and better protection from the weather. Spring assisted to allow the blades to open quickly. Ideal for use in roof curbs, ductwork, or wall collars when using a fan or power roof ventilator. Recommended for horizontal mount exhaust applications. MADE IN THE USA

Manufactured from 19-gauge galvanized steel frame 2" deep with 1" flange. For quiet operation aluminum blades have felted edges. Pre-punched conduit hole knock-out. Class 1.

Shut-off damper ADC is a 2-position, motorized damper without end switch. The damper is powered open with 24V AC, and is normally closed with spring return. Power supply wiring is connected to the lead wires attached to the damper motor. Positive closure is provided by a tight seal.

The IR is an iris damper for measuring and adjusting the air flow. The IR has the following specifications: low noise level, centrically-formed air flow and fixed test points for precise measurements. The damper also has an adjustment aperture which can be opened completely, which means there is no need for an access door for cleaning. Available in sizes 4-25 inches.

A low profile, fixed circular plastic exhaust grille. Included with the grille is a matching diameter galvanized mounting collar with nailing strip. Models DG with collar, models DGD with collar and back draft damper.