Centrifugal Fans and Blowers are common in air-handling and movement systems used in the chemical process industries. Some of the major uses of fans and blowers are in air-pollution-control systems, Ventilation and pneumatic conveying systems. Powering fans and blowers can contribute significantly to costs, and their efficient operation can be affected by the way the Fan capacities are selected. Furthermore, Air-pollution control systems must protect plant workers from the process, while also meeting all emissions standards set forth in local and national regulations. The system should also seek to minimize energy costs as well as replacement costs, such as service parts. The power required for an air handling system is computed using the following factors: