Jet fans are axial fans mounted in tunnel ceilings that push air longitudinally through tunnels without ductwork. These high-velocity fans efficiently move large air volumes across long distances in road tunnels, mine ventilation, and parking structures. They provide cost-effective ventilation by eliminating expensive ducting systems.
Technical Specifications
Jet fans typically range from 1.0 to 2.2 meters in diameter with power ratings between 15 and 75 kilowatts. They operate at rotational speeds of 500 to 1,500 RPM and produce thrust of 5,000 to 50,000 newtons. Installation spacing of 15 to 25 meters along tunnel length maintains consistent air velocity of 1.0 to 1.5 meters per second.
Applications
Road tunnels, underground parking facilities, and subway ventilation systems rely on jet fan arrays. Multiple fans work in sequence to push contaminated air toward exhaust points. Reversible jet fans can change direction seasonally or during emergency situations.
Design Advantages
Jet fans require minimal installation space and avoid the ducting costs that can represent 30 to 40 percent of traditional ventilation systems. Their simplicity reduces maintenance requirements and improves reliability in harsh environments.