Did you know?
A technical challenge
Building underground ventilation systems requires the implementation of ventilation shafts. Air is extracted from a tunnel linking two stations to an outlet grid at street level.
Upgrading or replacing ventilation equipment
More than 500 ventilation systems distributed throughout RATP’s underground facilities are used to extract air from the network.
Creation of a ventilation system
The creation of ventilation systems is being prioritised for metro lines equipped with rubber tyre trains, which give off more heat.
How is the project financed?
We are financing it 100%.
- Cost of creating a ventilation system: from €1m to €2m
- Average cost of upgrading or replacing a ventilation system: from €400,000 to €500,000
The air in our network
- Ventilation systems are found in the tunnels that link two stations. The ventilation system can be at a depth of between 10 and 40 metres, depending on the constraints of the underground environment.
- In comfort mode, the air in the tunnel is extracted at a speed of 60 m3/second to a grid at street level.
- In the event of a fire, the fans can be used for smoke extraction, away from the seat of the fire, at an air flow of up to 90 m3/second.
- The fan diameter can be up to 3 metres with a blade rotation speed of between 1,000 and 1,500 rpm.
Professionals and their jobs
Did you know that creating or overhauling a ventilation system involves many different professionals? For example: civil engineers, masons, and specialists in air, sound, electricity and vibration mechanics... A dozen technicians may be working simultaneously on a ventilation project.
To limit the noise at street level and meet acoustic regulations, the fans are fitted with soundproofing panels at street level and in the tunnels.