tunnel ventilation fan

The tunnel ventilation fan is a specialized fan system designed to supply fresh air and remove pollutants—including vehicle exhaust, dust, and heat—from underground tunnels and subway systems. They ensure safe atmospheric conditions for users and maintenance personnel.

Tunnel fans come in axial (jet fans) and centrifugal configurations. Jet fans are mounted directly in the tunnel ceiling to induce longitudinal airflow, while high-capacity axial or centrifugal fans at portals or shafts provide cross or transverse ventilation.

During normal operation, fans maintain air quality and temperature. In emergencies, high-powered fans switch to smoke extraction mode, rapidly clearing toxic gases and providing escape routes. Integration with fire detection and automation systems enables emergency ventilation sequences.

Construction materials include marine-grade aluminum and stainless steel to resist corrosion. Noise attenuation ducts, silencers, and aerodynamic blade designs minimize acoustic impact. Regular maintenance access and predictive monitoring ensure reliability in critical infrastructure.