Richelieu mechanical ventilation station

Construction of the Richelieu mechanical ventilation station

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The renovation of the rectifier station located near the future site of the Richelieu mechanical ventilation station will begin in September 2021.

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Project summary

As part of our program to refurbish our métro facilities and equipment, a new mechanical ventilation station is planned for the corner of Richelieu and Sainte-Marguerite.

The current station is located on the next lot over. Built in 1981, the station has now reached the end of its service life and must be replaced. Our project involves building a new, quieter and more efficient ventilation station that meets the new safety standards and complies with City of Montréal noise Montréal.


The existing building will be demolished, and a new structure will be built further back from the road. This new building will blend in with the rest of the neighbourhood’s architecture.

There will be a new green space between the road and the ventilation station, and shrubs will be planted around the building.

Duration of the work: Spring 2022 to fall 2025

Description of the work: Construction of a new mechanical ventilation station

Métro impacts: No

Bus impacts: No


News from the Richelieu MVS worksite – April 2021

Exploratory boring tests

Some boring work was done in summer 2020, but new samples are needed to complete the engineering studies. Soil samples are currently being taken at the back of the site in anticipation of the upcoming work.

Three exploratory geotechnical boring tests are being conducted to allow STM engineers to check the geotechnical data for the types of soil. The work is being conducted along the planned route of the tunnel to the mechanical ventilation station and will take about three weeks. It should be completed by May 7, 2021.

The boring tests are being conducted using a hydraulic unit, which may cause some localized noise and dust.

Securing the building

From now until late April 2021, the STM will be securing the building located at 4295 De Richelieu Street. The work will take place over two days, depending on the conditions on site and the weather. For a few hours, a mobile work platform will have to be parked in the entrance to the parking lot for the residences next to the worksite (4235 to 4269 De Richelieu Street).

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Independent public consultation for the Richelieu mechanical ventilation station
March 30 to April 15, 2021
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Learn more about the project

A mechanical ventilation station is an infrastructure located between two métro stations that is equipped with two fans designed to extract hot air from the métro network through inlets fitted with air vents. Ventilation stations built for the original métro network extract around 160,000 cubic feet of air per minute, while the new ventilation systems extract around 240,000 cubic feet per minute. Huge noise suppressors mitigate the noise from these fans to ensure quiet for residents living close to a ventilation station.

Mechanical ventilation stations serve three essential purposes:

Comfort ventilation
Regulates the ambient temperature and supplies fresh air for transit users by exchanging air from the outside with air inside the métro network.

Night-time ventilation
Ensures a supply of fresh air for night workers carrying out routine maintenance.

Emergency ventilation
In the event of an incident, controls smoke and provides a safe evacuation route for passengers via the nearest métro station and ensures unobstructed access for emergency first responders.


The required excavation work will generate occasional vibrations that may be felt by residents near the worksite. An independent consulting firm will survey (photograph) all buildings around the work site. These inspections will document the condition of the buildings before and after construction. In the unlikely event that any damage is reported, an expert opinion will help to determine whether the damage is the result of the vibrations produced by the work site. Property owners affected by this measure will be contacted before the worksite opens.

This project will be completed in several phases:

  1. Worksite preparation
    1. Fencing off the worksite
    2. Demolishing the existing building and fully decontaminating the area
    3. Installing underground infrastructure and fill
  2. Ground-level excavation
    1. Fencing off the worksite
    2. Setting up the worksite and installing equipment
    3. Conducting ground-level MVS shaft excavation
  3. Bedrock excavation
    1. Open-cut ventilation shaft excavation
    2. Underground ventilation tunnel excavation
    3. Micro-blasting may be required for excavation in the rock bed, but other options will be assessed with the general contractor
  4.  Installation of a membrane to ensure watertightness of all infrastructures
  5. Concrete work for ventilation station
    1. Concrete work for all infrastructures
  6. Installation of mechanical and electrical equipment, as well as architectural finishes and exterior design
    1. Delivery of equipment to worksite
    2. Installation of equipment
    3. Performance testing on mechanical equipment
    4. Construction of ventilation station’s external structure

Frequently Asked Questions

No. Essentially, a mechanical ventilation station exchanges the air inside the métro that transit users breathe with outside air, ensuring a constant supply of fresh air.

There are no contaminants in a mechanical ventilation station. Rainwater or snow falling into the ventilation shaft will be collected by the métro’s water-pumping system and released into the municipal sewage system, as is currently done throughout the métro network.

Once the ventilation station is operational, the noise it emits will comply with municipal by-laws.

The fans are installed below ground level and equipped with powerful noise suppressors. The noise level outside the building will not exceed 50 decibels, even when the ventilation station is operating at full capacity, which is unusual. The station’s noise level will be comparable to that of a household dishwasher. In fact, it will be so low that normal conversation or ambient noise could easily cover it.


The worksite is a considerable size. We have to dig into the rock bed to create a vertical shaft to a depth of 21 metres. We will then excavate a 92-metre tunnel, removing a total of 9820 cubic metres of bedrock from the site. After that, we will install a waterproofing membrane over the tunnel to protect it from water infiltrations. Next comes the concrete, which will form the tunnel and underground building. Finally, fans and their accompanying electrical equipment will be installed. All of these steps vary in terms of duration and impact, such as noise and dust.


This work is made possible through funding from the Ministère des Transports du Québec.

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