Most of the fans we build are driven by electric motors, and this requires the fan wheel and/or shaft to connect with the motor shaft in some way. There are two broad classifications we use to describe this connection – 1) belt drive and 2) direct drive.

A belt drive connection means that the fan shaft and motor shaft will be outfitted with sheaves (pulleys) and then connected with belts. With different sized sheaves, the fan can operate at the speed required for the application and doesn’t have to operate at the motor synchronous speed.

If there is a direct drive connection, the fan wheel will either mount directly on the motor shaft or the fan shaft will be directly coupled to the motor shaft. Since it is directly connected to the motor, the fan will operate at the same speed as the motor.

Which Option is Most Popular

Traditionally, process engineering and maintenance folks preferred belt drive fans because the fan speed isn’t limited by motor synchronous speed and can be adjusted in the field by swapping out sheaves and belts to change the fan speed. This provides flexibility in the system design and manufacturing process.

For some applications, a belt drive connection also offers protection to the motor by separating it from the gas, materials, and or temperature in the fan airstream.

Today, that has changed. We sell far more direct drive fans. With Variable Frequency Drives (VFDs), you can control the speed of any fan, including direct drive fans, by simply pushing a button or two on the control panel. VFDs allow operators to adjust fan speed (within the fan’s design capabilities) to match exactly what they need for their manufacturing process. The added flexibility, efficiency, and ease of use have made direct drive fans a preferred choice for most applications.

Our Recommendations?

Our application engineers evaluate hundreds of applications each month and provide recommendations on the best way to drive the fan for each project. For most applications, we recommend direct drive over belt drive.

With VFDs, there’s no reason to choose belts and sheaves strictly for the ability to change performance in the future. It’s just too easy with a VFD. Direct drive is also more efficient, as there are no horsepower losses from the belt connections.

In terms of motor protection from the fan airstream, we would not recommend certain direct drive options if you are working with extremely hot temperatures or with material going through the fan. However, we would recommend our direct drive models where the fan and motor shafts are coupled together.

When it comes to maintenance, we will always recommend direct drive. There are fewer parts to take care of and replace. That means your maintenance costs should be lower and your fan should live longer.

Finally, we put ourselves in our customers’ shoes and consider the capital expenditure against the operating expenses. For some applications, a direct drive fan has the lowest upfront and operating costs. For others, the belt drive option is the best choice with a significantly lower upfront cost. Most of the time, belt drive and direct drive options are very comparable in price, and for these, direct drive fans offer the highest cost savings due to their lower operating costs.


The drive configuration is one of the many factors to consider when buying your fan. For most applications, we recommend using a direct drive fan for all the stated reasons, but not always. Our application engineers are happy to look at the specifics of your application and recommend the best option for you.

Please complete our contact form, and one of our engineers will connect with you.

Related Content

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