Direct Drive Fans

Fan Arrangements Using Direct Drive Motors

Your fan arrangement, dictated by AMCA standards, starts with the motor that runs it. Direct drive fans are the most simple. The motor directly connects to the fan wheel – either the wheel is mounted on the motor shaft or is directly coupled with the motor shaft.

Fan arrangements that use or allow a direct drive have some important benefits. These include lower maintenance as a result of fewer parts, a tighter footprint, and better efficiency for very large fan applications.

Direct-Driven Fan Arrangements

Arrangement 4 Fan

An Arrangement 4 Fan is simply a direct driven fan with the fan wheel mounted to the motor shaft. Its simplicity and minimal components make it a less expensive design than others. This is the most basic fan arrangement, where the fan wheel mounts directly on the motor shaft. There are no other drive components.

For more information and a demo video, visit our blog: Basic Overview: Arrangement 4 Fan

Arrangement 4V Fan / Top Mount Fan

The AirPro arrangement 4V centrifugal top mount fan allows the fan inlet flange to mount directly to the outlet flange on top of a dust collector, cyclone, bin vent, etc. The fan wheel mounts directly on the motor shaft but, unlike other arrangements, the shaft and motor are in a vertical position.

The 4V arrangement saves space and money often spent on extra ducting. Additionally, as a result of the direct connection and lack of additional ducting, less static pressure is present in the system thereby increasing efficiency. Typical accessories are outlet dampers, silencers, weather guards, & bird screens.

For more information and a demo video, visit our blog: Basic Overview: Arrangement 4V Fan

Arrangement 7 Fan

The primary feature of the Arrangement 7 Fan is that it has bearings on both the inlet and the outlet. It can have a direct drive or a belt drive configuration. The placement of a bearing on the inlet side of the Arrangement 7 Fan means that there is no horizontal inlet. As a result, it requires an inlet box to direct the air into the fan from above or from the side.

In our Arrangement 7 Fan, the wheel hangs in the center. We have a bearing on the inlet side of the inlet box, which is welded to the fan housing. The other bearing is mounted on the drive side of the fan housing. Finally, the fan shaft is directly coupled to the motor shaft in most applications. It is also possible to use a belt-drive with an Arrangement 7.

For more information and a demo video, visit our blog: Basic Overview: Arrangement 7 Fan

Arrangement 8 Fan

The fan shaft connects directly to the motor shaft with a flexible coupling. This arrangement offers fewer potential maintenance issues than other arrangements, as there is no belt pull on the bearings, and the motor experiences neither belt pull nor the weight of the wheel on its shaft. Importantly, OSHA guards are required, and a unitary base may be required.

Arrangement 2 Plug Fan

An Arrangement 2 Fan can use a belt drive or a direct drive motor. More commonly known as Plug Fans, the fan mounts to an enclosure to circulate air in a clean, contaminated or high temperature environment. Generally designed to move high volumes of air at low static pressures, this high temperature fan allows for several wheel designs and with various materials (like aluminum and stainless steel) that are appropriate for the specific operating temperature.

Arrangement 3 Fan

An Arrangement 3 Fan can use a direct drive or a belt drive motor. It Involves a bearing on either side of the fan wheel. The bearing is supported either by separate pedestals or by a support structure integrated with the fan housing. In order for an Arrangement 3 Fan to operate properly, it must include these parts:

• Fan Assembly (wheel, housing, & pedestal base)
• Shaft
• Bearings
• Motor
• V-belt Drive OR Direct Drive
• Bearing Support pedestals OR supportive fan housing

Helpful Resources

For information on Belt Drive Fans, including Arrangement 1 and Arrangement 9, visit Belt Drive Fans.

For information on determining which kind of Arrangement you need, please take a look at our Blog, Industrial Fans: Belt Drive or Direct Drive.