Publié 12/01/2023
Schools: Is the air you breathe of good quality?

In 2020, the Ministry published the Real Estate Planning Guide: Primary Schools. This document defines the guiding principles promoting academic success, which depends above all on the quality of teaching and learning facilities. Air quality is one of the factors on which these guiding principles are based. Providing good indoor air quality to students and school staff is demanding, but beneficial. The expense and effort invested in preventing most problems in this regard is usually significantly less than that required to resolve them.


Indoor air quality is considered good when it does not usually cause health problems for people who frequent the various premises of a building.

Good indoor air quality is based on four priority objectives

  • Minimize indoor contaminant emissions;
  • Maintain an acceptable level of humidity and temperature;
  • Ventilate the building well to ensure an adequate supply of fresh air and an adequate number of air changes per hour;
  •  Minimize the introduction of outdoor air pollutants.

Indoor air quality is a complex phenomenon that can involve many parameters, including the outdoor environment, the components of the building, its maintenance, ventilation, the occupants and, finally, the regulations in force. Indoor air quality can also be influenced by certain comfort parameters, in particular those related to temperature, relative humidity, the supply of fresh air from outside, the number of air changes per hour and the concentration of carbon dioxide (CO2). The majority of schools are not mechanically ventilated. School bodies must therefore ensure that they comply with the regulations in force and provide for mitigation measures in exceptional situations, particularly with regard to the temperature and relative humidity outside.

Potential Issues

Poor air quality problems, such as those created by the presence of excessive humidity, can cause physical damage to building structures and electromechanical equipment. They can also be costly for educational organizations due not only to the appearance of health problems among the occupants and the deterioration of the work climate, but also to the expenses related to the search for causes and the implementation of urgent solutions, which will sometimes be temporary. Moreover, studies show a correlative link between an increase in the concentration of CO2 in enclosed spaces, such as classrooms, and certain effects on humans: sore throats, runny nose and reduced capacity for mental effort. In addition, the media coverage of issues related to air quality can contribute to negatively labelling the schools concerned and the entire network of school service centres.

Standards and targets in schools

In order to maintain good air quality in schools, the following targets have been issued:

  • A daily average CO2 less than 1,500 ppm can be used as an adequate comfort parameter. Moreover, the Direction générale de la santé publique confirmed its support for the use of this indicator in a correspondence dated November 27, 2022;
  • The Department’s target for educational facilities and Health Canada’s threshold is a daily average CO2 less than 1000 ppm;
  • A relative humidity rate varying between 30% and 50%, depending on the season; 
  • An ambient temperature varying between 20 °C and 26 °C.

Table des matières

Publié 12/01/2023
Schools: Is the air you breathe of good quality?

Table des matières