A turning vane is an internal curved or angled blade installed inside ductwork at bends and transitions to guide airflow smoothly while reducing pressure drop and turbulence. Turning vanes maintain laminar flow at duct elbows and reduce friction losses by 30 to 50 percent compared to sharp 90-degree bends. These devices are essential in high-velocity ductwork systems where pressure recovery and noise control are critical.
Technical Specifications
Turning vanes are typically spaced 3 to 6 inches apart within duct bends and manufactured from galvanized steel or fiberglass. Single-curve vanes are most common, though double-curve designs provide superior performance in critical applications. Properly designed vanes should extend 85 to 95 percent across the duct cross-section to minimize bypass air.
Performance Benefits
Turning vanes reduce noise generation at elbows by breaking up turbulent vortices that occur at sharp transitions. They allow higher airflow velocities through bends while maintaining acceptable pressure drops below 0.1 inches of water column per elbow. Installation of turning vanes is particularly important in main trunk lines and high-pressure ductwork carrying 2000 to 4000 CFM.