Accurate motor control reduces noise and vibration in laboratory flow hoods

High levels of motor noise and vibration was above acceptable levels for the use of a ventilation flow hood used in a sensitive laboratory environment. That was until variable frequency drive (VFD) technology was introduced.
 
The fan was being driven by a single-phase motor controlled by a Pulse-Width Modulation (PWM) system. This provided limited control over the speed of the fan resulting in noise at up to 72dB, in addition to significant vibration.