Keeping a fan running 24-7 is not inherently bad, especially in industrial and mining ventilation where continuous operation is common and sometimes mandatory. The key question is whether the fan and its motor are designed, selected and maintained for continuous duty at the required load. If they are, operating around the clock can be perfectly acceptable. If they are not, continuous running may accelerate wear, increase failure risk and waste energy.
Most medium and large ventilation fans used in mines, tunnels and process plants are specified for continuous duty. Their motors, bearings and cooling systems are designed to run for long periods without rest. In fact, main mine fans and many process exhaust fans are expected to operate 24 hours a day for months at a time, stopping only for scheduled maintenance or major repairs. In these cases, continuous running is part of the design and is not harmful as long as the fan operates within its rated conditions.
Problems arise when a fan that was not designed or selected for continuous service is forced to run 24-7, or when the duty has changed and the fan is now overloaded. Excessive temperature in the motor, high vibration, or operation near stall can all damage bearings, insulation and impellers over time. In such cases, it is not the continuous operation itself that is bad, but the fact that the fan is working outside its comfort zone continuously instead of only occasionally.
Another consideration is energy consumption. A fan running 24-7 consumes significantly more electricity than one that runs only when needed. If airflow requirements vary during the day, using automatic controls and variable-frequency drives to reduce speed during low-demand periods can save a lot of energy while still maintaining safety and environmental conditions. Continuous full-speed operation in periods of low demand may be technically possible but economically and environmentally inefficient.
Continuous operation also affects maintenance planning. If a fan never stops, it can be harder to find time for inspection, cleaning and lubrication without interrupting production or ventilation. In critical mining applications, plants often install redundant fans or parallel systems so that one fan can be taken offline for maintenance while another maintains airflow. Without such planning, components may run until failure, leading to unplanned downtime and higher repair costs.
In summary, it is not automatically bad to keep a fan running 24-7. For industrial and mining ventilation fans designed for continuous duty and correctly loaded, round-the-clock operation is normal. The important points are to ensure proper selection, monitor condition, plan maintenance and, where practical, use control strategies that match airflow to demand to avoid unnecessary energy use.
