High Plume Dilution Fans have been around since 1986. They were developed by Strobic Air for an application at the IBM plant in Fishkill, NY. The facilities engineers at IBM wanted a fan that would get process exhaust fumes up and away from the roof. They wanted to make the roof a safe environment to work on. At the same time they wanted a fan that would require a minimum amount of maintenance.
Strobic Air developed an answer in the Tri-Stack Fan. The Tri-Stack Fan uses a patented nozzle design to maintain stack velocities while minimizing horsepower. Increased stack velocities allow the fan to entrain outside air (up to 170% by volume). Process air and entrained air combine to produce a substantially diluted exhaust stream, and a safe work environment (without tall stacks).
The other key design feature in the Tri-Stack Fan is the direct drive motor. IBM engineers insisted on little or no maintenance. The Tri-Stack Fan Direct drive motors are virtually maintenance-free with typical bearing lifetimes of L-10 100,000 hours. IOM maintenance calls for 2 ounces of grease every 18 months.
Here are some of the key features that were included in the first high plume dilution fan.