Retrozone&Flexdamper are trademarks of Retrozone Inc.

 Free Standard Shipping on Orders $25+ Continental USA only

  Shipping to Alaska, Hawaii, and International shipping to Canada extra. Please place the order and factory will advise of additional shipping amounts prior to shipping. 

Credit Cards will not be charged until shipping amounts are verified. 


Expedited shipping available. Please call for pricing. 

When selecting the motor on the short side of any damper over 24” it is considered Jackshafting.

*Jackshafting requires bolting two dampers together and adding a longer shaft to control all the parts together.

Current cost for Jackshafting is $34.00****Additional Time for production as well

SDTF Series Dampers: 

Commercial Quality Rectangular Motorized Louver Damper. 

Applications include Zone Control, Outside Air Intake, Exhaust Air Vents - control airflow in any HVAC Duct System.

   •     2 position Spring Return Belimo TF Actuator

    •     18 in. lbs. motor Torque

    •     Available as PO/SC or PC/SO

    •     Damper Blade Position Indicator

    •     The actuator may be stalled anywhere in its normal

         rotation without the need of mechanical end switches.

         Power consumption is reduced in holding mode. 

    •     24V or 120V Motor options

    •     Extruded Aluminum Frame / Blades

           with Reinforcing Channels

    •     Mounting Plate - 5" wide X Damper Height

    •     Frame - 2 1/2" wide / Blade width 1.438" within Frame 

    •      Standard 1/2” drive shaft accepts many different motors

    •     Oil Impregnated Bronze Bushings

    •     75 Sec - Power Drive / 25 Sec - Spring Return

    •    50 dB - Power Drive / 62 dB - Spring Return

    •     5 VA / 2.5 Watts

    •     5 year warranty

    •      Works with most zone panels

    •     Available in odd sizes, one inch increments, 

        like 9x15 (contact us for pricing)

SDTF Series Commercial 

Spring Return Rectangular Damper

with Belimo two-wire motor in 24v or 120v

These are CUSTOM, Made-To-Order dampers

 that take approximately 3-4 business days to make

Please see our Surplus Dampers that are in stock.

How to order a standard damper:

Just buy the damper in the size want, select your voltage, 24 or 120, then select what side you want your motor mounted, long side or short side (all sizes over 24 inches require bottom “long side” motor mount) and if you want it Normally Open (use when hooking up to a zone control system) or Normally Closed (use when hooking up to a thermostat or switch).

Custom Built and Ships in 48 Hours!

The SDTF Damper is a motorized rectangular, opposed blade, damper constructed of an extruded aluminum frame and blades, stainless steel slide, and a Belimo TF spring return motor, available in 24V (standard) or 120 / 230V (optional). The TF actuator, with it's 5 year warranty, delivers 18 in. lbs. of torque. Applications include zone control, outside air, exhaust air vents, although they may be used to control air in any system duct. Standard configuration is power open / spring return closed. Power close / spring return open is optional.

Rectangular Damper Questions You need to answer

 to COMPLETE Your Order:

A. Size, like; “08 inches x 24 inches”

B. What side the motor is on using the selected measurements; like “8 inch side”

C. Normally Open or Normally Closed when unpowered:

This means with no power applied, is the damper open?

or closed? Important: When used with a zone control system, you will need to order normally open. When used tied directly to a thermostat or switch, you will want to order normally closed.

D. Rectangular dampers are custom made and not returnable due to size or configuration errors.

Please carefully review your confirming invoice to ensure correct product for your application.

SDTF Series Commercial Spring Return Rectangular Damper, rectangular dampers, mechanical damper, custom damper, hvac, air conditioning supplies, RetroZone


Size Dampers

8x6 ($235.15) 

10x6 ($235.15)

12x6 ($235.15) 

14x6 ($237.25) 

16x6 ($241.50) 

18x6 ($247.70) 

20x6 ($249.80) 

22x6 ($261.40) 

24x6 ($265.60) 

8x8 ($235.15) 

10x8 ($235.15)  

12x8 ($235.15)  

14x8 ($237.25) 

16x8 ($241.50) 

18x8 ($247.70) 

20x8 ($249.80) 

22x8 ($261.40) 

24x08 ($265.60) 

10x10 ($239.35)  

12x10 ($239.35) 

14x10 ($245.55) 

16x10 ($247.70) 

18x10 ($253.00) 

20x10 ($265.60)

22x10 ($267.70) 

12x12 ($249.75) 

14x12 ($249.75) 

16x12 ($253.00) 

18x12 ($255.10) 

20x12 ($267.70) 

14x14 ($253.00) 

16x14 ($255.10) 

SDTFM Medium

Size Dampers

26x6 ($269.85) 

28x6 ($271.95) 

30x6 ($276.15) 

32x6 ($278.25) 

34x6 ($280.35)

36x6 ($283.45) 

26x8 ($269.85) 

28x8 ($271.95) 

30x8 ($276.15)

32x8 ($278.25) 

34x8 ($280.35) 

36x8 ($283.45) 

24x10 ($271.95) 

26x10 ($276.15) 

28x10 ($278.25) 

30x10 ($280.35)  

32x10 ($283.45) 

34x10 ($287.65) 

36x10 ($289.75) 

22x12 ($276.15) 

24x12 ($278.25) 

26x12 ($283.45) 

28x12 ($285.55)  

18x14 ($259.30) 

20x14 ($276.15) 


Size Dampers

30x12 ($287.65) 

32x12 ($289.75) 

34x12 ($295.05) 

36x12 ($297.15) 

20x14 ($276.15)

22x14 ($280.35) 

24x14 ($285.55) 

26x14 ($289.75) 

28x14 ($289.75) 

30x14 ($295.05) 

32x14 ($297.15) 

34x14 ($301.35) 

36x14 ($303.45)

16x16 ($267.75) 

18x16 ($269.85) 

20x16 ($283.00) 

22x16 ($285.55) 

24x16 ($289.75) 

18x18 ($271.95) 

20x18 ($287.65) 

22x18 ($289.75) 

24x18 ($299.25) 

20x20 ($301.35) 

22x20 ($301.35) 

24x20 ($303.45) 

22x22 ($303.45) 

24x22 ($305.55) 

24x24 ($307.65) 

rectangular dampers, mechanical damper, custom damper, hvac, air conditioning supplies, RetroZone

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