Belt Drive - Vane Axial fans are designed for commercial and industrial applications where large volumes of air are required at moderate to high pressures. Belt drive vane axial fans accommodate for final system balancing and have manually adjustable blade pitch. These fans are an excellent choice for variable air volume HVAC systems, clean rooms, parking garage exhaust, and tunnel ventilation. For sound critical applications, belt drive vane axial fans are available with Greenhecks Sound Trap Housing.