Zonefirst SPRD-18 Damper

The Zonefirst SPRD-18 is a professional-grade 18-inch round barometric bypass damper engineered to maintain critical static pressure relief in multi-zone HVAC applications. As zone dampers close, this single-blade mechanical component automatically responds to rising pressure, diverting excess airflow to the return plenum or a dump zone to prevent coil icing and blower motor strain. Unlike motorized alternatives, the SPRD-18 utilizes a counter-balanced weighted arm for precise calibration, allowing technicians to set exact static pressure regulating thresholds. It is rated for systems up to 0.5” W.C. and effectively manages airflow volume to reduce high-velocity noise at the registers. Constructed with durable materials for long-term HVAC zoning reliability, this 18” damper is essential for protecting constant volume systems from bypass-related performance drops. The mechanical design requires no electrical wiring, making it a robust solution for both residential and commercial bypass ducting requirements where air pressure stability is paramount.

• Precise Pressure Management: Automatically relieves excess duct static pressure to maintain HVAC system efficiency.
• Field-Adjustable Calibration: Features a calibrated weight and arm assembly for fine-tuning the opening point based on specific system CFM requirements.
• Acoustic Optimization: Significantly reduces air whistling and "banging" sounds associated with high-velocity air in small zones.
• Equipment Protection: Helps prevent high-limit trips and evaporator coil freeze-ups by ensuring proper bypass airflow.
• Flexible Installation: Suitable for horizontal or vertical 18" round duct configurations.

How do I set the correct pressure on the SPRD-18?
Calibration should be performed while the system is running with all zone dampers open. Adjust the weights so the blade remains closed under full design flow, then verify it opens effectively as individual zones are deactivated.

Can this damper be installed in vertical duct runs?
Yes, the Zonefirst SPRD-18 is compatible with vertical installations; however, the weighted arm must be specifically adjusted to compensate for the weight of the damper blade in that orientation.

Does this unit require a power supply?
No, this is a barometric bypass damper. It operates purely on mechanical air pressure differentials and does not require 24V wiring or actuators.

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.