Road Tunnel Ventilation - Longitudinal Ventilation

Longitudinal ventilation is achieved by using jet fans or booster fans that, through an exchange of momentum between jet fans and mass of air in the tunnel, are able to induce a large fresh air flow into the tunnel. During fire scenario they avoid smoke back layering and keep under control the smoke propagation maintaining clear zones occupated by users.

For longitudinal ventilation Systemair offers a wide range of jet fans:

Jet fans AJ and AJ(TR)

• Unidirectional (AJ) or truly reversible (AJ(TR))
• Diameters from 500 to 1.600 mm
• Thrust up to 2.100 N
• Up to 400°C for 2h operation
• Certified according to EN 12101-3
• Casings and silencers in heavy gauge, hot dip galvanized after manufacture
• Systemair jet fan performance tests follow ISO 13350 standard


Mojet ®

• Unique, energy-saving solution for longitudinal ventilation
• Combines the advantages of jet and Saccardo nozzle
• Special converging nozzles (outlet silencers) accelerate the air flow
   with an increase in thrust
• The downward inclined nozzles increase the installation factor up to 0.9  
   (normally 0.7 to 0.78)
• The result is:
   - Reduced number of jet fans required, 
   - less power requirements,
   - less cabling cost,
   - less electrical cabinet cost,
   - hence a significant reduction of running cost.