After more than two years of the pandemic, ventilation and air quality in Quebec schools remain an issue. According to an analysis of data obtained by: The duty According to the Access to Information Act, nearly half of Quebec’s public primary and secondary school buildings are not mechanically ventilated.
As a result, 45% of institutions must use “natural” ventilation, ie opening windows, because they do not have a mechanical system, according to construction phase data from the Ministry of Education. By adding buildings where the ventilation system is only partial – when part of the building is mechanically ventilated and the other is not – there are 61% of primary and secondary schools that are not fully served by mechanical ventilation.
However, mechanically ventilating a school is the best way to better control air exchange parameters, say experts consulted by The duty† This is also why new schools are being built with a mechanical ventilation system, says construction engineer and member of the COVID-STOP collective Manuelle Croft.
« C’est beaucoup plus simple parce qu’on peut utiliser des systèmes de contrôle pour gérer la ventilation de manière qu’elle soit activée pendant l’occupation et qu’elle puisse s’adapter aux besoins des usagers », résume-t- she.
Conversely, it is difficult to ensure a constant supply of fresh air by relying only on opening the windows, especially because of the wind that changes direction and speed throughout the year, says Stéphane Bilodeau, engineer and air quality specialist, also a member of the COVID-STOP collective.
“Natural ventilation may be sufficient for a few days a year, but it will not be sufficient for the supply of fresh air for the majority of the year. could be [le vent] not even going in the right direction i.e. we would rather circulate air from inside to other classes than air from outside [vers l’intérieur] “, he says.
The Ministry of Education, for its part, confirms that “the built buildings” [dans les années 1960 et 1970] were designed to promote natural ventilation through the orientation of the building, the use of skylights, the design of corridors, etc.”.
However, the disadvantages of natural ventilation go much further than air quality, says Manuelle Croft. Whoever’s children attended naturally ventilated schools during the pandemic says her concerns weren’t so much about the type of ventilation as about the responsibility of school staff.
“That’s the problem with natural ventilation. The mental load of ventilation rests on the shoulders of people who already have a high mental load. […] When we are in the heat of the action of our education, we are not necessarily sensitive to the fact that it has been a long time since we opened the windows,” she underlines.
For his part, Stéphane Perron, health and environmental medical specialist at the National Institute of Public Health of Quebec (INSPQ), believes that the two ventilation systems can be just as effective as the other if they are properly maintained and “optimized”.
“Mechanical ventilation also has its complexities. It must be very well maintained. In theory we think it could be higher [à la ventilation naturelle]but in practice it is not always so clear,” he adds.
The Ministry of Education has Task that by calculating the types of ventilation based on the surfaces of the primary and secondary buildings, 67.4% of the surfaces would be mechanically ventilated.
Air quality not guaranteed
A mechanically ventilated school does not necessarily equate to good air quality. CO readers2 provided to teachers during the pandemic have made it possible to measure significant differences in readings within the same school, denounces the Dd Marie-Michelle Bellon, specialist in internal medicine and coordinator of the collective COVID-STOP.
“In schools where there was mechanical ventilation, [le taux de CO2] was completely variable from class to class. In the same school there were levels of CO2 impeccable in some classes and others where for some reason the numbers were super high. †
This is the case for Cindy (fictional name), a high school teacher in the Lanaudière region. The person whose identity is being protected for fear of reprisal from her employer told the Task that, despite the mechanical ventilation that serves his establishment, many buildings exhibit abnormal CO. levels2† Many of these classrooms do not even have a window to ventilate the premises.
“We were told to open the door. […] But not much happens when a door is open,” she says with a touch of irony.
When Cindy regrets that the “poor ventilation” and the heat have harmful effects on both the concentration of the students and the energy level of the teachers, she especially denounces the “lack of coherence” of the management of the file. “Because we are mechanically ventilated, we are considered ‘ok’. We conduct annual interviews. [du système], but there are no plans to improve it. †
The teacher says he has not received any news about work or palliative measures for the next school year. However, the summer holidays are the ideal period to carry out construction sites, argue many speakers, such as the president of the Autonomous Federation of Education, Sylvain Mallette.
“We know that the virus spreads less when it is warm. Infection rates have always decreased during the summer period, but in the autumn the same questions will arise when the cold weather sets in and we have to close the windows,” he said indignantly. mr. Mallette calls for lowering the “acceptable” concentration threshold of CO2 from 1500ppm to 1000ppm, as well as the reintroduction of COVID-19 outbreak monitoring.
the dd Marie-Michelle Bellon, of the COVID-STOP collective, also hopes for concrete measures in anticipation of the autumn. “Summer is the time to act, the students are not there. In addition, if we look at what is happening in Portugal and Great Britain, a new wave is on the way,” she says.
For its part, the Ministère de l’Éducation du Québec (MEQ) ensures that: Task that “all CSS [centres de services scolaires] and CS [commissions scolaires] have completed or planned projects related to indoor air quality in their buildings”.
CSS and CS plan to invest $225 million in ventilation by 2022, the MEQ says.
Even if children are generally less likely to develop severe symptoms of COVID-19, they can still spread the virus to those around them, recalls virologist Benoit Barbeau, professor in UQAM’s Department of Biological Sciences.
“If your ventilation system is not adequate and you are unable to [d’assurer] good air exchanges, it is sure to accentuate your risks of transmission. And this prevention applies to all other respiratory viruses, he emphasizes.
For engineer Stéphane Bilodeau, it is essential to tackle “the problem of air quality”, especially in naturally ventilated classrooms. “Temporarily it is better to open the windows, because sometimes that helps. It’s better than doing nothing, but it’s not a long-term solution. It is a cast on the bobo”, he concludes.