Brief Introduction : 

1. This is a Centrifugal Fan including an ECM (Brushless Motor), a set of volute, a  centrifugal fan and a plastic air-inlet device. 

2. The ECM (Electronically Commutated Motor) is a high efficiency programmable  brushless DC motor utilizing a permanent magnet rotor and a built-in inverter. 

3. DC motor is significantly more energy efficient than AC motor and much easier  to control. The energy saving is upto 65% in average compared to shaded pole  motor, or 35% compared to PSC motor. 

4. The motor is of long lifetime, wide range of applications and speed regulations. 

5. It’s generally available for products of low speed (generally less than 6000RPM). 

6. It’s with large rotation inertia, simple structure & not accurate starting position.