Zonefirst AOBD-20X8 Damper

The Zonefirst AOBD-20X8 is a high-performance automatic opposed blade damper designed for precision airflow management in commercial and residential HVAC zoning. This 20" x 8" unit features a robust 24Vac power open/power closed actuator, requiring a 3-wire connection for positive drive control in both directions. Unlike standard gravity or spring-return models, the AOBD-20X8 side mount damper utilizes a synchronous motor that draws power only during its 30-second transition, improving energy efficiency and eliminating the "chatter" common in low-voltage systems. The opposed blade configuration ensures balanced static pressure and reduced turbulence, making it an essential HVAC zoning solution for systems exceeding 0.5" W.C. Constructed from extruded anodized aluminum with stainless steel linkages, this motorized duct damper is built for long-term reliability in high-cycle environments. Integrated end switches provide 100% confirmation of damper position, allowing for seamless integration with advanced zoning control panels and automation systems.

• Precision Airflow Management: The opposed blade design prevents "hot spots" in ductwork by providing a more uniform air distribution pattern compared to parallel blades.
• High-Torque Performance: The 24Volt AC actuator provides consistent force to overcome static pressure, ensuring tight closure and full opening even in high-velocity systems.
• System Feedback: Built-in end switches allow contractors to verify damper status at the control board without physically inspecting the ductwork.
• Durable Construction: Heavy-duty aluminum frame and stainless steel draw bars resist corrosion and mechanical wear in diverse plenum environments.
• Quiet Operation: Precision-engineered gears and self-lubricating bushings ensure smooth, silent blade movement during zone transitions.

How do I wire the Zonefirst AOBD series for power open/power closed operation?
This model utilizes a 3-wire terminal block. Typically, you will connect a common 24V lead and two switched leads from your zoning control panel or SPDT thermostat to drive the motor to its limit in either direction.

Can this 20x8 damper be installed in a vertical duct?
Yes, the AOBD-20X8 is a side-mount unit with the motor on the 8" side, making it suitable for both horizontal and vertical orientations as long as there is adequate clearance for the actuator housing.

What happens if the power fails?
Because the AOBD-20X8 is power open and power closed, it will remain in its last position during a power outage. This provides more stability in commercial applications where accidental "fail-closed" scenarios could lead to coil freezing or high-pressure bypass issues.

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Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.