Model BD-31

Backdraft Damper
Fabric Style Blade

The BD-31 backdraft damper employs gravity operated fabric style blades to restrict airflow and to permit the forward flow of air in the intended direction. The BD-130 damper may be mounted vertically or horizontally (airflow up) in either exhaust or intake installations for low to medium velocity and pressure applications.

Standard Construction

Frame: 2" x 1/2" X 0.06" (51 x 13 x 1.5) extruded aluminum channel.
Blades: Double-coated neoprene Ventglas woven fiberglass-fabric.
Backing: 1/2" x 19 ga. (13 x 2) wire mesh.
Minimum Size: 6" x 6" (152 x 152)
Maximum Size: Single Section: 36" x 24" (914 x 610)
                           Multiple Section: Unlimited

Ratings

Leakage: 21.0 cfm/ft² @ 4.0 in. wg. (0.11 m³/s/m² @ 1.00 kPa)
                 19.0 cfm/ft² @ 3.0 in. wg. (0.10 m³/s/m² @ 0.80 kPa)
                 11.0 cfm/ft² @ 1.0 in. wg. (0.06 m³/s/m² @ 0.25 kPa)

Temperature: -65^oF to 400^oF (-54^oC to 204^oC)