The Model 411 is a non-flanged/drop-in frame horizontal mount automatic backdraft damper. It is designed to allow airflow in one direction and to prevent reverse airflow. The blades open with airflow and close by gravity when the fan shuts down. Models are available for exhaust or supply (intake) as well as for vertical mount applications. Ideal for use in roof curbs, duct work, or wall collars when using a fan or power roof ventilator. Do not use with any kitchen exhaust applications.
The Model 413 is for supply (intake) applications.
Frame: 2" deep Galvanized Steel with a conduit knockout for easy electrical hook up.
Blades: 26 gauge 3105 Aluminum with spring assist to allow blades to open quickly.
Seals: Felt on leading edge of blades for tight closure and quiet operation.
Tie Rod: Galvanized Steel for uniform opening and closing.
Bushings: Nylon with 304 Stainless Steel pivot pins.
Construction: Tog-L-Loc corners.
Sizes (see chart on Submittal Dwg. for std. sizes):
Minimum: 8" W x 8" H
Maximum: 30" W x 30" H
2000 FPM Maximum Velocity.
1" wg Maximum Pressure.
180 degree Maximum Temperature.
Motor pack (Model MTR-611 - see submittal dwg.)
1" Flanged frame - exhaust or supply (intake).
Aluminum 1" flanged frame for exhaust only.
Manual pull chain operator.
Custom sizes available in whole inch increments.
We recommend mounting the damper at least 1/3 the fan diameter away from the fan blade.