The main function of a fan is to create a controlled flow of air by generating a small pressure difference. Instead of letting air sit still or move only when the wind blows, a fan uses a rotating impeller to push or pull air through openings, ducts, rooms, tunnels and underground workings. This basic ability to move air on demand is the foundation of all mechanical ventilation, from a small bathroom exhaust fan to a multi-megawatt mining ventilation fan.
When a fan runs, its blades add energy to the air. On the suction side, the pressure is slightly lower than the surrounding atmosphere; on the discharge side, the pressure is slightly higher. Air naturally flows from high pressure to low pressure, so this difference drives air through the ventilation system. The fan does not create or destroy air; it simply moves and redistributes it according to the needs of the process or workplace.
In industrial plants and workshops, the function of the fan is to supply fresh air and remove polluted air. Axial and centrifugal fans deliver airflow through ducts and hoods so that dust, fumes, odours and heat are carried away from people and equipment. Some fans act as supply fans, pushing conditioned air into the building; others act as exhaust fans, pulling contaminated or hot air out to the outside atmosphere.
In underground mines and tunnels, the fan’s function is directly tied to safety. Main mine fans, booster fans and auxiliary fans must ensure that every working area receives enough oxygen and that harmful gases such as methane, diesel exhaust and blasting fumes are diluted and removed. Without fans to move air through shafts, drifts and headings, it would be impossible to keep underground conditions within legal and practical limits for gases, dust, temperature and humidity.
Fans also support cooling and thermal control. By moving air across hot surfaces or through cool intake routes, they limit temperature rise in electrical rooms, motor halls, conveyor galleries and deep mine levels. In some systems, fans work together with heaters, coolers or chillers, ensuring that conditioned air reaches all necessary locations.
In summary, the main function of a fan is to create controlled airflow and pressure so that air can be moved where it is needed for ventilation, cooling and contaminant control in buildings, factories, tunnels and underground mines.
