• 30350 Ecorse Road, Romulus, MI 48174
  • 734-326-0050



611 - Galvanized frame / Aluminum blades - 31"-60" - No flange - Exhaust or Supply

The Model 611 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 613 is for supply (intake) applications.

Vertical mount dampers require field modifications to the standard product via a conversion kit. The blades will pivot at the bottom and fall with gravity.

Standard Construction:
Frame: 2" deep Galvanized Steel with a conduit knockout for easy electrical hook up.
Blades: 26 gauge 3105 Aluminum with a Galvanized Steel reinforcement strip and spring assist.
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.
Finish: Mill

Sizes (see chart on Submittal Dwg. for std. sizes):
Minimum: 31" W x 31" H
Maximum: 48" W x 60" H
Multiple panels for sizes over 48" W x 60" H.

Performance Criteria:
2250 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.
Vertical mount conversion kit.

We recommend mounting the damper at least 1/3 the fan diameter away from the fan blade.


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Backdraft Dampers

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About ACP

Family owned and operated since 1947, Air Conditioning Products Company (ACP) is a world-class manufacturer of shutters, dampers, louvers, and other products for air movement equipment.