Motorized HVAC Damper – Normally Closed

(14 customer reviews)


Category: HVAC Damper – Subcategory: Motorized Material: Galvanized Steel – Finish: Mill – Thickness: 28 Gauge Shape: Round – Dimensions: 4″, 5”, 6″, 7″, 8″, 10″, 12″, 14″ – Sku: ADC

Download the Product Specs .PDF


SKU ADC Categories ,


The FAMCO ADC Motorized HVAC Damper - Normally Closed is normally closed with a power open and spring return motor assembly. The ADC is made with 24 volt or 120 volt motors. End switches are available with all models. End switches allow another appliance to be operated when the damper has reached its full power (either open or closed). The floating motor mount assures proper alignment of motor, shaft and damper to prevent binding, while the clutch/coupler reduces the number of moving parts for greater service life. All units without the end switch come with a flow control adjustment so that the damper blade can be blocked from opening or closing 100%. (Note: the end switch will not work if the flow control adjustment is preventing the damper from reaching it's full potential.) Quality constructed in 28 gauge Galvanized steel. The FAMCO ADC Motorized HVAC Dampers come in a range of diameters: 4 inch, 5 inch, 6 inch, 7 inch, 8 inch, 10 inch, 12 inch, and 14 inch. The FAMCO ADC Motorized HVAC Damper is manufactured by FAMCO in the United States and comes with a 1-year warranty against product defects and workmanship. If you have any questions about this product, please refer to the FAQs above or feel free to contact us.

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Spec Sheet

Questions and answers of the customers

  1. Q What is the current draw on ADC424? answer now
    Asked on February 16, 2021 5:26 pm

    The current draw on our 24 volt motors is 0.36 amps. 

  2. There are no answers for this question yet. Answer now
  3. A

    We do not have CFM ratings data for this product at this time.

  4. A

    No, there is no flange, the foam gasket is adhered directly to the inside walls of the tube.

  5. Q What is meant by "End Switch"? answer now
    Asked on November 30, 2020 12:06 pm

    Our end switch is a physical limit switch built into the bracket that will only activate when the damper is in the fully powered position - this switch has lead wires for connecting to an additional appliance, like an inline fan, that you would only want to power on after the damper is fully powered.

  6. Q How do I specify Normally Closed on my order? answer now
    Asked on November 30, 2020 12:05 pm

    We have separate product pages for our normally open and normally closed dampers, so if the product description on the page says "normally closed", then you are ordering the correct damper.

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14 reviews for Motorized HVAC Damper – Normally Closed

Based on 14 reviews
5 star
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1 star
  1. Ed

    Good product

    Pros: Heavy gauge metal, good seal, good value, and the reason I bought these is the included end switch.

    Cons: I realized that an enclosed junction box is not required with 24 volts, but I would prefer to see a junction box and a conduit knock-out for a cable grip.

    I have not yet installed these, will update review after they are put into service.

  2. Wood burner

    Works great

    Works great

  3. Jeff Van Kirk

    worked great

    just what we needed

  4. Terrance KAMINSKI (verified owner)

  5. Joseph Smail (verified owner)

    reasonably priced with a quick turnaround, Quality workmanship!

  6. Paul (verified owner)

  7. Anonymous (verified owner)

    Great customer service

  8. Anonymous (verified owner)

    Very fast service, excellent robust product. Good packaging, never anything damaged in shipment. Thanks!

  9. Anonymous (verified owner)

    Well made and solid. Nice to get something made in North America.

  10. Anonymous (verified owner)

    I have not installed this damper yet, but the quality looks really good.

  11. Gary Booth (verified owner)

    just took a bit longer than i thought.

  12. Charles Gully (verified owner)

  13. Anonymous (verified owner)

    Great product! Nice quality construction.

  14. Thomas D. (verified owner)

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