Case Study

Accurate motor control reduces noise and vibration in laboratory flow hoods

Accurate motor control reduces noise and vibration in laboratory flow hoods


Vibration and noise caused by poor motor control from a PWM system were creating problems in the operation of ventilation flow hoods used in laboratory settings.


The PWM system was replaced by an Optidrive E3 variable frequency drive. This provided accurate control of the fan motor which reduced the vibration and noise.


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.

Specialist laboratory equipment manufacturer AmbiKontrol of Brazil turned to Invertek Drives for a solution to reduce the noise and vibration levels by being able to vary the fan’s motor speed.

“Laboratory flow hoods provide safe ventilation in a number of applications in laboratory environments. In this case, the motor control was a simplistic PWM system. The poor control meant the motor created noise and vibration that was not acceptable in such a sensitive environment,” said Marcus Silva, Invertek Drives Head of Sales for Latin America.

“We introduced an Optidrive E3 variable frequency drive to the application. A combination of its ease to set up and commission, along with its ability to provide accurate speed control, meaning the problems associated with the old system were solved immediately.

Noise levels and vibration reduced dramatically

“The noise levels dropped to below 62dB and the issue of vibration was resolved. It also gives operators much more control over the level of ventilation needed by altering the speed of the motor.”

In this case, the Optidrive E3 used was a 05HP single phase input/output, 220V, 4.3A, with an IP20 enclosure.

The compact size of the drive meant it could be easily fitted to an existing panel, taking up little space.

“The Invertek solution made our equipment move to a different level when compared with our competitors,” said a spokesperson for AmbiKontrol.

Noise levels reduced by up to 62db

“We immediately had a reduction of up to 62dB in noise levels, in addition to motor vibration. Our customers noticed this straight away and were impressed with the system.”

AmbiKontrol produces a range of laboratory products including biological safety cabins, exhaust chapels, instrument sterilizers, BOD/DBI incubators, Culture medium preparers, orbital shakers, and air treatment units.

Marcus added: “Once again we have been able to demonstrate the ability of the Optidrive VFD range to provide accurate motor control capable of not only providing energy savings but resolving issues such as noise and vibration through the control of motor speeds.”

Easy to set up and commission

The Optidrive E3 is part of Invertek Drives range of easy to use and set-up VFDs. The E3 includes simple commissioning, with 14 parameters basic set-up, default settings, and up to 50 parameters available for flexible use.

It comes with an intuitive keypad and application macros for switching between industrial, pump, and fan modes, dependant on the application being controlled.