Centrifugal fans comprises of housing, impeller and drive arrangement. The housing is of sheet irom with circular inlet and rectangular outlet. Centrifugal fans are designed and manufactured in different ranges. The basic difference lies in the design of the impeller. The impellers are precision balanced for smooth vibration less operation. The fans can be fabricated in M.S., Stainless Steel, Aluminium, etc., depending on the kind of application. Various coatings such as F.R.P., Hot Dip Galvanising, Epoxy, etc., are also available as an option.