Ventilation in Schools

Thames Valley District School Board gratefully acknowledges special funding provided by the Government of Canada and Government of Ontario that will support improved ventilation of schools. Funding received through the Investing in Canada’s Infrastructure Program (ICIP) will be utilized for enhanced preventative maintenance of Heating, Ventilation, and Air Conditioning (HVAC) equipment and the purchase of MERV 13 filters. This will ensure each student, staff member and visitor to TVDSB facilities experiences the highest air quality possible. (This funding acknowledgement was initially posted on January 9, 2023.)

Along with vaccinations, masks, physical distancing and proper hand hygiene, ventilation is another measure that can help prevent and slow the spread of COVID-19 in schools.

Thames Valley is making ongoing efforts to optimize air quality in classrooms and learning environments through improving ventilation and/or filtration. 

Parents and the community can be assured that all TVDSB schools will be operating within full compliance with all Ministry of Education and Public Health guidelines. 


Most TVDSB schools have full mechanical ventilation, which is routinely inspected and in good working order throughout the year. The frequency of the filter changes has been increased. In tandem with this, filter quality has also been improved where possible. Ventilation systems are also operated for extended hours, pre and post occupancy, to increase the daily air exchange. 

To date, Thames Valley has invested $64.9 million to install or upgrade school mechanical ventilation systems, with 50 projects already completed.  An additional $30.8 million has been allocated for planned ventilation projects during the 2022-2023 school year, with 14 projects planned or already in progress.   

View TVDSB's Ventilation Strategy

View TVDSB'S Board-Wide Investment Profile

Understanding Ventilation Systems

Ventilation is the process of supplying or removing air from a space for the purpose of controlling the indoor air quality within the space. The types of ventilation systems commonly in use at TVDSB schools are:

  • Mechanical Ventilation – This is ventilation provided by motor-driven fans. These systems may include supply fans which push outdoor air into a building and exhaust fans which expel air out of a building.  These systems also condition the air through the use of heating and/or cooling equipment so that air is delivered to the space at comfortable temperatures. 
  • Passive Ventilation – This is ventilation delivered to the space primarily by air diffusion through doors, windows or other intentional openings in buildings, assisted by exhaust fans to draw fresh air into a building. 
  • Combined Ventilation – Schools that have had one or more additions built over time may have a combination of mechanical and passive ventilation systems. Passive ventilation would typically be found in older sections of a school while newer sections would most likely be served by mechanical ventilation systems.

View a list of Ventilation Systems at TVDSB Schools.

HEPA (High Efficiency Particulate Air) Filters

A mobile HEPA filter in a classroomMedical-grade, fan-powered HEPA filtration units have been shown to reduce the spread of airborne infections in health care facilities by removing viruses, bacteria and allergens as small as 0.3 microns from the air. 

The use of HEPA filtration units, in combination with improved ventilation strategies and existing health and safety protocols, work together to reduce the risk of COVID-19 transmission and support a safer environment for staff and students.

As of August 22, 2022, 5,951 HEPA filter units have been delivered and installed in Thames Valley schools.   

For schools with passive or partial mechanical ventilation, portable HEPA filtration will be installed in a variety of classrooms and other spaces.  

The HEPA filter units have been deployed to all classrooms, libraries, and gyms in Thames Valley schools.

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