Zonefirst ZDS-18X16 18WX16H Parallel 24V 2-Pos S/R

The Zonefirst ZDS-18X16 is a heavy-duty, side-mount rectangular zone damper engineered for precision airflow management in 24V zoning systems. Featuring an 18”W x 16”H extruded aluminum frame and parallel blades, this unit is designed for a side-mount installation where the motor is located on the height dimension. The parallel blade damper design utilizes 3" blades pivoting on self-lubricating bushings, ensuring silent operation and a long service life under static pressures up to 1.0" W.C. This 2-position spring return (S/R) actuator comes standard as power close/spring return open, providing a fail-safe "normally open" state that prevents complete airflow blockage during a power loss. For specific site requirements, the ZDS-18X16 features a field-reversible motor and a minimum position adjustment screw, allowing technicians to bleed a small percentage of air through the duct without needing a separate bypass damper. This HVAC zoning damper is 1/4" undersized to ensure a seamless fit into standard ductwork slots.

• Fail-Safe Operation: The 24V spring return motor ensures the damper returns to the open position if power is lost, protecting the system from static pressure spikes.
• Rugged Construction: Built with an extruded aluminum frame and zinc-plated linkage for superior corrosion resistance and structural integrity in high-velocity air streams.
• Field Flexibility: Includes a minimum position set screw to allow for constant air bleed and can be field-converted to power open/spring close in minutes.
• Simple Installation: Designed for rapid side-mount insertion into a 4-inch slot, reducing labor time for retrofits and new construction zoning projects.

Is this damper "Power Open" or "Power Closed"?
Standard ZDS models are power closed and spring return open. However, the linkage and motor can be field-configured to power open by following the manufacturer's reversal instructions.

Can I use this for a bypass application?
While primarily a zone control damper, the integrated minimum position adjustment allows it to act as a localized bypass by preventing the blades from sealing 100% when powered.

What happens if the motor fails?
The spring return mechanism automatically pulls the blades open. The motor is also easily replaceable via a single set-screw on the damper blade shaft, requiring no duct disassembly.

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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.