TUNNEL VENTILATION IN ROAD TUNNELS

Abstract: Road tunnel ventilation systems serve to limit the concentration of air pollutants during normal tunnel operation and to transport smoke gases out of the tunnel during self- and assisted rescue in case of fire. Depending on the tunnel length, the traffic load and type, as well as the likelihood of traffic jams, different ventilation systems, such as longitudinal, semi- or fully transverse ventilation systems, are used. A combination of these systems is sometimes required. Ventilation is the defining issue for many tunnels and the safety and comfort of the people who use them, especially during extreme events such as fire. Wrongly conceived, it can lead to excessive demands on tunnel size and cost, and even undermine the feasibility of a project. One should always, specialize in simple, practical and sustainable solutions to tunnel ventilation and wherever possible, to harness natural ventilation. A tunnel's length and function obviously affect the viability of this, but by minimizing mechanical plant, we save both excavation and operating costs, creating less energy-intensive, more sustainable alternatives.

Keywords: Tunnel Ventilation, air pollutants, smoke, gases, longitudinal & transverse ventilation system