The Zonefirst SPRD-9 is a professional-grade 9-inch round barometric static pressure regulating damper engineered for precise HVAC bypass management in multi-zone systems. This mechanical, non-electrical component utilizes a weighted counter-balance arm to automatically relieve excessive static pressure as individual zone dampers close. When the air pressure in the supply plenum exceeds your calibrated setpoint, the damper blade opens to bypass air into the return duct or a designated dump zone, preventing high-velocity noise and protecting equipment from short-cycling or coil freeze-ups. Built for durability, the SPRD-9 handles up to 0.5" W.C. of static pressure and is rated for airflow capacities up to 600 CFM. Its inline design and 10-inch sleeve length allow for rapid integration into standard round rigid ductwork. This damper is an essential solution for technicians looking to maintain constant system CFM and optimize the efficiency of the zoning system without the complexity of electronic controls. Key Benefits for Contractors Precise Pressure Calibration: The adjustable weighted arm allows for fine-tuning the opening point based on the specific static pressure requirements of the air handler. System Protection: Effectively mitigates high-limit trips and evaporator coil icing by maintaining a consistent airflow volume through the furnace or air handler. Acoustic Performance: Reduces the "whistling" or air noise common in zoned HVAC systems when only the smallest zone is calling for conditioned air. Simplified Installation: Standard 9" crimped-end design facilitates a quick inline connection into bypass ductwork. Common Questions How do I adjust the opening pressure on the SPRD-9? Loosen the thumb screw on the counterweight to slide it along the arm. Moving the weight toward the end of the arm increases the pressure required to open the blade, while moving it toward the shaft decreases the resistance. Can this damper be installed in a vertical duct run? Yes, the SPRD-9 supports both horizontal and vertical mounting. For vertical installations, the counter-balanced arm must be carefully adjusted to offset the natural gravity of the damper blade. What happens if the system exceeds 2000 CFM? For high-capacity systems over 2000 CFM, it is recommended to transition to an electronic static pressure control (SPC) and a motorized damper (MARD) to ensure stability beyond the mechanical limits of barometric bypass. This item is not eligible for free shipping. 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.
