Gearless/direct drive fans represent the next step in HVLS fan technology. A truly gearless HVLS fan does not have a gearbox and in turn runs quietly, costs less to operate, and is less prone to wear and tear than traditional gear-driven fans.
But not all gearless HVLS fans are created equal. You must consider all key features so that you can choose a high-performance fan for your facility.
1. Truly Gearless
Some HVLS fan manufacturers market their products as gearless, but they actually use a more sophisticated type of gearbox to power the fan – not a direct drive motor. Fans with even the most advanced gearboxes are still prone to wear and tear because the seals in the box break down and the lubrication between parts wears away over time. Make sure to ask your manufacturer why the HVLS fan you are considering is gearless. Ask specifically if the motor uses gear reduction/speed altering. If it does, it means that the motor uses gears and is not a direct drive.
2. Motor Type
The motors for MacroAir's direct drive fans are a brushless permanent magnet AC type motor. They are a 60-pole motor which allows for greater resolution and modulation of the fans rotation. Direct drive motors offer reduced noise, greater efficiency, and reduced number of mechanical components. This is all in stark contrast to the gear driven fan. In a gearbox type fan you have to worry about proper lubricants, proper gear mesh, potential leaks, in addition to the higher number of moving parts. With the direct drive motor, you have fewer moving parts which equals less maintenance. What's more, direct drive motors offer increased efficiency due largely to no major mechanical losses. The motor’s power is primarily used only to bring the blades up to speed.
3. Drive Technology
An HVLS fan's drive is what controls the motor and sets the operating speed of the fan itself. Ideally, the drive is mounted directly to the motor which eliminates problems with electromagnetic interference. Also, choose a fan with a drive specifically designed for powering a fan motor. These specific drives are less likely to malfunction than generic drives used to power any kind of motor.
4. Fan Performance
The most important element of buying an HVLS fan is how well it performs. At the end of the day, your fan is designed to do one thing – move air. Make sure that the gearless fan can move the volume of air you need to be circulated in your space. Key performance indicators include the fan’s CFM (how many cubic feet of air the fan moves per minute), typical spacing (how many fans are necessary for the space), and set-point change (how much cooler/warmer the space feels when the fan is on).
The Bottom Line
If you choose the right one, a gearless HVLS fan can make your facility quieter and more comfortable while reducing your monthly energy costs. Be sure to speak with a specialist before you invest to ensure you fully understand the features, benefits, and application of a gearless HVLS fan.