Booster Fans and Airflow Optimizers FAQ

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When is a booster fan required?

When the ducting is restricted by length of run or number of elbows to create a backpressure in excess of .5” W.C. A typical installation is a multi-story building or an installation with a long horizontal run. In most cases a length of duct in excess of 50 feet will require a booster fan.

What type of fan is typical for boosting airflow with a dryer(s)?

Usually a belt driven tubeaxial round duct fan is used. A tubeaxial fan will handle dryer lint and also operate at high temperatures created in the drying process.

Where is the fan usually mounted?

It is normally mounted in close proximity to the downstream side of the lint filter. The fan speed will also have a faster response time with a variable frequency drive equipped application.

What happens when a single speed booster fan is on and several of the dryers are off?

It is essential that the booster fan and dryers are handling matching airflow volumes. An Airflow Optimizer with variable frequency drive will control the booster fan speed to keep the airflow within proper operating parameters. At the very least, a barometric damper should be installed between the filter and the fan if an Airflow Optimizer is not installed.

What is the result of the booster fan drawing more than the dryers are exhausting?

If the filter has a lint bag, it will be drawn into the filter. The result will cause the redeposited lint to be pulverized into a powder consistency allowing it to go through the screen.

Should I use a bag or ridged container to store the lint under the lint filter?

It is necessary to use a ridged lint container. Never use a lint bag to store lint when using a booster fan.

Why doesn’t the fan always run when equipped with an Airflow Optimizer?

If the backpressure is below the set point, the fan assist is not required and the fan will stay turned off until the set point is reached.