Having introduced high-volume, low-speed (HVLS) fan technology to the market in the 1990s, MacroAir Technologies continues to focus its product development around delivering high level results in terms of efficiency. Some customers have reported reductions in energy use of up to 70%, according to MacroAir.
At first glance, commercial and industrial fans may seem an unlikely place to look for such significant energy savings. However, MacroAir continues to raise the bar in terms of what’s achievable from a product design perspective. One of the company’s latest innovations — the six-blade industrial fan — outperforms the company’s ten-blade fan series while requiring 40% less aluminum and 13% less power to manufacture. Shipping costs are also reduced because the new six-blade fan weighs 30% less than the ten-blade fans.
An added benefit to the six-blade HVLS approach to fan design is reliability. “As RPM goes up, torque goes down. Torque is what hurts motors and causes them to fail,” says Jeff Johnson, MacroAir engineer. “Six-blade commercial fans run slightly faster than 10-blade fans, and the torque is lower; less torque means more life.”
On the automation side of the six-blade fan design and its ability to deliver on its energy efficient claims, MacroAir engineers point out the fans’ power units. The gearmotors specified by the engineers for their HVLS fans are the Lenze GST 05 and GST 06, as well as a range of inverters, including the Lenze-AC Tech SM/SF Series.
Johnson says he prefers the Lenze GST gearmotors because the gears are made from case-hardened steel, and that they are helical rather than spur gears.
“Helical gearing has the gear teeth cut at an angle in relation to the axis of rotation as opposed to a spur gear where the teeth are parallel to the axis of rotation,” Johnson explains. “The advantage to a helical gear is that there is more tooth contact and more of a ‘rolling’ effect as the gears mesh.”
Johnson contends that with more contact in the teeth of the gears, there is more torque. Plus the ‘rolling’ effect he described reduces gear noise.