In your industry, give a Macro view to your existing fan as a system. Study whether you can retrofit, replace the sub system components to reduce the overall energy loss by 10 % conservatively, by low to medium cost Energy conservation Measures.
The industry is using the centrifugal blower in many of the process in the production and in utility. As a system, the centrifugal blower system efficiency is the multiplied efficiencies of each of the sub systems like the motor, VFD, belt, pulley & drive, and the main impeller. Hence your Blower system which consumes at the input as 100 units, delivers only 30 units at the output.
ASSESS YOUR BLOWER’S OVERALL SYSTEM EFFICIENCY