Fans for industrial and commercial buildings have evolved significantly over the past couple of decades.
To be clear, industrial fans (also called HVLS Fans, commercial fans, and barrel fans)are most commonly used for circulating air and creating cooling breezes for occupants. Industrial fans come in many different sizes and configurations to accommodate a host of different needs. While sizes and configurations can vary greatly, industrial fans typically utilize one of three different drive systems:
- AC Induction Motor + Gear Reduction Drive
- DC Brushless Motor (Also Known As Direct Drive)
- AC Induction Motor + Belts and Pulleys
Understanding industrial fan drive systems will help us make more informed buying decisions. There is no such thing as a superior drive system, just as there is no such thing as a superior type of combustion engine. If we need to haul heavy equipment over long distances, we are very likely to purchase a truck with a diesel engine and a heavy-duty transmission. This doesn’t mean diesel trucks are absolutely superior to gasoline trucks; diesel is just the best option for the job we need to accomplish. Fan drive systems are very similar. We need to understand the pros and cons of each drive system to determine which option is best for our needs.
AC Induction Motor + Gear Reduction Drive
Common uses:
- HVLS Fans
Gear reduction drives utilize a series of interconnected gears in an enclosed bath of gear oil to reduce the rpm to a desired range. The gear oil helps reduce the amount of friction created between the interconnected gears, which increases the life of the gears. Less friction means less heat is generated.
Pros:
- A tried-and-true method for industrial fans.
- Widely used in many different products and industries
- Can meet a wide range of torque and rpm requirements
- Many brands of gear reducers available to fan manufacturers
Cons:
- Even high-quality gear reducers create noise (which can be problematic in some applications)
- Most seals will deteriorate over time – resulting in gear oil leaks and eventually damaging the gear reducer (If not corrected)
- Fairly complicated replacement process, especially if the fan is in a hard-to-reach area.
- Some industrial fan manufacturers may force you to purchase replacement parts through them.
- Some industrial fan manufacturers may not allow gear reducers to be replaced in the field – forcing you to replace the entire drive unit (Motor, gear reducer, and maybe even the fan hub)
DC Brushless Motor / Direct Drive
Common uses:
- HVLS Fans
- High-Speed Directional Fans
- Mobile Fans
DC Brushless Motors require either a variable speed drive or an onboard processor to control the speed of the motor. Since the speed of the motor can be directly matched for the desired rpm, there is no need for any other type of speed reduction (Hence, “Direct Drive”)
Pros:
- Usually very quiet operation, no mechanical noise.
- No risk of seal failures or gear oil leaks
- No risk of gear reducer failure and no belts to replace or maintenance
- Can reduce overall weight of an industrial fan (no gear reduction needed).
Cons:
- Electronics can be sensitive to harsh environments.
- Motors contain rare earth magnets, which can result in greater costs than other drive systems.
- All things being equal, direct drive tends to be more expensive than other options.
AC Induction Motor + Belts and Pulleys
Common Uses:
- Barrel Fans
- Directional Fans
- Mobile Fans
- Super Duty Fans
This type of drive system is a simple, effective means of prime mover and rpm reduction. Unlike a gear reducer, which uses a series of interconnected gears to reduce rpm, this system utilizes different-sized pulleys connected via a high-tension belt (the same type of system used to spin an alternator or AC pump on an automobile engine)
Pros:
- Smooth, quiet operation
- Simple, reliable design
- Less weight than a gear reducer/transmission
- Low cost
- Easy to maintenance
- Easy to replace
- Allows for multiple hanging methods (no gear oil to worry about )
Cons:
- Belts and pulleys require routine maintenance
- There are limitations to the torque output
- Aesthetics may not be desirable for some applications
About Super Duty Fans
Founded by Phil & Kelly Eggers, Super Duty is on a mission to make the highest quality industrial fans accessible to businesses of all sizes, everywhere. Their fans are handcrafted in Texas, USA, using the highest quality metal components. You won’t find cheap plastics or low-cost composites in these fans. They are called Super Duty for a reason!
Phil and Kelly did not grow up dreaming of the industrial fan business, but they dreamed of being entrepreneurs and living the American Dream. They discovered fans together and have committed themselves, and their nest egg, to building this premier industrial fan company. Both came from highly successful corporate careers and now implement their knowledge to provide a wonderful product and service experience for their customers.