The main function of a booster fan is to increase pressure and airflow at a specific point in a ventilation system. Instead of replacing the main fan, a booster fan works in series with it, adding extra pressure where the system resistance is high. This allows fresh air to be pushed or pulled through long tunnels, remote mine districts or complicated duct networks that the main fan alone cannot ventilate efficiently.
In underground mining ventilation, a booster fan is typically installed in a main airway to raise the pressure of the air stream as it travels deeper into the mine. The main surface fan generates the overall pressure difference between intake and return shafts, while the booster fan adds extra pressure in a particular branch. This helps maintain required airflow to far-away production levels or long declines without overloading the main fan or dramatically increasing its size and energy consumption.
In industrial ventilation and duct systems, a smaller booster fan may be installed in a section of duct that suffers from low airflow due to distance, bends or filters. By adding pressure locally, the booster fan helps restore design air quantities to remote rooms, process hoods or equipment enclosures. The function is the same as in mining: overcome additional resistance in one part of the network while keeping the rest of the system operating at efficient conditions.
A well-designed booster fan does more than simply spin faster air. It is selected so that its pressure–flow curve matches the upstream and downstream system. When correctly chosen and controlled, the booster fan raises the total pressure available to push air through difficult sections but does not create recirculation or unstable flows. In mining, this means ensuring that air still travels from intake to return airways as planned, and that no contaminated return air is drawn back into intake circuits.
Because booster fans are located inside the system rather than at the boundary, their function also includes fine control of ventilation distribution. By adjusting booster fan speed or inlet vanes, engineers can change how much air is delivered to particular branches, balancing energy use against airflow requirements. This is especially useful in large mines and complex industrial plants where demand changes over time.
In summary, the function of a booster fan is to provide additional pressure and airflow inside a ventilation system so that remote or high-resistance areas receive enough fresh air. In mining and industrial applications, this targeted boost allows designers to meet safety and production requirements without oversizing the main fan.
