Wiseman mechanical ventilation station

Construction of the Wiseman mechanical ventilation station

Project summary

The construction of the Wiseman mechanical ventilation station, located on the vacant lot between Dollard Avenue and Wiseman Avenue, is part of our program to refurbish our métro facilities and equipment. The new station will replace the old Wiseman MVS, which has reached the end of its service life.

Duration of the work: January 2022 to fall 2024

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

Métro impacts: No

Bus impacts: No

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Impact on local residents

We will be digging a vertical shaft to a depth of 15.1 metres into the bedrock, then tunnelling horizontally for 4.7 metres. In total, 5511 cubic metres of bedrock will be removed from the site. After that, we will install a waterproofing membrane over the surface of the tunnel to protect it from water infiltrations. Next comes the concrete, which will form the tunnel and underground building. Finally, the fans and their accompanying electrical equipment will be installed in the building. All of these steps vary in terms of duration and impact, such as noise and dust.

Anti-dust sheets will be installed on the worksite partitions and trucks will be cleaned before leaving the worksite.


  • Noise management for the project will be overseen by experts.
  • When possible, electric cranes and compressors will be used to reduce noise and CO₂ emissions.
  • Construction noise will be minimized by partitions of varying heights made of wood and filled with acoustic insulation. These noise walls will be placed strategically around the edge of the worksite during different work phases, based on noise simulations produced by an expert company. The walls will reduce the noise caused by the worksite.

Construction will be carried out according to the schedule authorized by municipal by-laws, from 7:30 a.m. to 7:00 p.m. on weekdays.

An information session was held on January 11, 2022. Below are the questions that were asked by participants and the answers provided by the STM team.

  • We have imposed constraints in the work contract requiring contractors to implement a noise management program. Here are some of the requirements imposed in the specifications: Noise limit imposed on the contractor via the work contract for most activities
  • Noise control program developed by a specialized acoustics firm hired by the contractor
  • An STM acoustics consultant will:
    • Supervise compliance with the contractor’s noise control program
    • Implement measures to ensure compliance for the entire duration of the worksite’s active period
  • Noise screens to be installed around certain worksite equipment
  • Adjustable-volume or white-noise backup alarms to be installed on trucks

Our worksite communications service at the STM usually publishes a newsletter for residents living near the site when we are preparing for a particular task or transitioning to the next work phase.

Vibrations will be minimal thanks to the excavation method that will be used and how close the site is to the métro tunnel. Depending on your home’s soil composition, you may feel vibrations at certain times. An expert hired by the entrepreneur will inspect potentially affected buildings before the start of the work. The buildings could also be reassessed after the work is complete. If this applies to your building, you will have already received a letter.

Trucks will enter the worksite via the Rockland overpass and Thérèse-Lavoie-Roux Avenue. The number of trucks will vary depending on the type of work being done. At the height of the digging period, there may be up to roughly 15 trucks per day. Also, a flagger will be present when trucks are driving on Thérèse-Lavoie-Roux to ensure cyclist and pedestrian safety.

Yes, our worksite has been coordinated with that of the school.

Once the work is complete, the MVS will comply with all City of Montréal noise by-laws. Huge noise suppressors will mitigate the noise from the fans, installed below ground level, to ensure quiet for residents living nearby. The new MVS will make no more noise than the one currently in operation at the same site.

Learn more about the project

A mechanical ventilation station is a large infrastructure located between two métro stations that is equipped with two powerful fans designed to extract hot air from the métro system through inlets fitted with air vents. Ventilation stations built for the original métro system extract around 60,000 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.

  1. 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.
  2. Night-time ventilation: Ensures a supply of fresh air for night workers carrying out routine maintenance.
  3. 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.

No. Once the ventilation station is operational, the noise it emits will comply with municipal by-laws. The fans are installed below ground and equipped with powerful noise suppressors. The level of noise generated by the ventilation station will remain in compliance with municipal by-laws, 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.

For more information on mechanical ventilation stations, visit the page in the Major Projects section.

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