Higher range fans can be indigenously designed & supplied. Total efficiencies of these fans range up to 83% & higher efficiency fans can be designed by incorporating high performance fan features like selection of low inlet entry angles, rounded entry by curve formed shroud, 'S' type or twisted blades to achieve low entry inlet angle & high outlet angles in same configuration. To achieve best possible efficiency we also resort to low inlet angles and higher diameters to make up for low outlet angles. These features, with properly designed inlet box having turning vanes can achieve 90% total efficiencies. ID Fan Impellers are constructed in backward inclined straight blades duly hard faced for easy of release of fly ash dust particles to reduce impeller erosion. Construction material can be carbon steel, alloy steel or stainless steel to withstand duty conditions. FD & SA Fan impellers are generally fabricated in carbon steel. Fan casings are constructed in minimum 5mm thick carbon steel duly stiffened for mechanical strength. Shafts & Bearings are designed for minimum stresses & predetermined life respectively. VIV dampers are supplied for power saving when same fan operates at different operating points. Fan impellers are dynamically balanced to ISO grade G-6.3. Fans are shop tested for performance as per IS 4894.