The use of our switch-board QE-AC-INV-RX equipped with inverter and digital pressure gauge is the most advanced and effective but still simple solution to control extraction according to the actual quantity of extraction points.

The pressure gauge determines constantly how many extraction points are open andhow many are closed (by measuring thesystem global pressure) and transmits this information to the inverter that AUTOMATICALLY adjusts the rotation speed of the engine. As we know in centrifugal fans the air volume is directly proportioned to the engine speed. 

By reducing the speed of about 30%, the air low of the fan will also be reduced of 30%. The Energy co sumption, however, will be reduced of about 65%. The existing relationship between air flow, pressure, speed and power are indicated in the diagram.