Ventilation

Community members can now view school-specific Standardized Ventilation Reports for our HWDSB buildings. This dashboard, which was standardized by the Ministry of Education, displays each school’s ventilation system along with other ventilation and filtration measures. Access the reports through the Excel document linked below.

School Ventilation Report September 2023

To find your school, use the dropdown menu next to “School Name” and select your desired school. The content will then change to display the selected school’s information.

To continue creating and supporting a healthy and safe learning environment for students and staff, school boards should continue enhancing air quality in classrooms and learning environments.

The guidance for the 2023-24 school year builds on the best practice/checklist document released by the Ministry of Education in August 2021 (2021: B14 School Ventilation) and, where applicable, has been augmented to reflect the latest information from ASHRAE. School boards should review applicability of this guidance, with qualified persons, in the context of their school facilities and related building systems (including manufacturer recommendations) to ensure improvement measures are aligned with the specifications of existing systems.

School boards are expected to:

• Ensure ventilation systems in all schools are inspected and in good working order for the new school year.
• Continue inspection and maintenance of ventilation systems throughout the year.
• Calibrate HVAC systems for maximum air flow and increased fresh air intake, while recognizing specification and limits of existing systems.
• Use highest rated Minimum Efficiency Reporting Value (MERV) filter that can be accommodated by the system (MERV-13 if possible) and regularly:
  • Inspect filters to make sure they are installed and fit correctly.
  • Replace filters and consider increasing frequency of filter changes to maintain overall performance.
  • Check that sufficient airflow can be maintained based on HVAC design criteria.
• Keep ventilations systems running when buildings are occupied, including by support staff and vendors.

School boards are recommended to consult ASHRAE guidance in the context of their facilities operating parameters and system specifications, working with qualified persons as required (e.g., building engineers and occupational hygienists).

For buildings/rooms that rely on natural ventilation/no HVAC system:

• Open windows for short times at intermittent intervals, if safe to do so (assess to prevent re-entry of building exhaust). Doing so for a few minutes at a time during the day can still improve air quality, with minimal impact on the indoor temperature.
• Assess exhaust systems (review to ensure exhaust air is not re-entering the building e.g., windows, science labs, washrooms) and ensure restroom exhaust fans are functional and operating at full capacity when the building is occupied.

Ontario’s leading standard of a standalone HEPA unit in every kindergarten class, in all learning spaces in schools without mechanical ventilation and mechanically ventilated spaces that are not supported by MERV-13 filters, continue to be required by the province. As noted in prior memos, portable HEPA units are highly effective at capturing and removing airborne particles and pollutants, and in turn significantly improving indoor air quality. In operating these units, school boards are expected to:

• Size the units appropriately for the classroom or learning environment in which they are used. For instance, in larger classrooms and learning environments, more than one HEPA unit may be required.
• Regularly maintain units per manufacture requirements, visually inspect intake for debris and clean as necessary.

School boards should also ensure that implemented measures do not introduce new health hazards to the setting, for example:

• Do not open windows and doors, if doing so poses safety or health risk to students and staff, e.g., risk of falling, triggering asthma symptoms, exposure to wildfire smoke etc.
• Do not prop open fire doors to increase ventilation and/or reduce exposure to frequently touched door handles.
• Avoid use of technology or devices that may pose safety or health risks, e.g., commercially available ionizing air cleaners and other unproven technologies. The following documents provided by Public Health Ontario are a good resource:
  • Use of Portable Air Cleaners and Transmission of COVID-19 (publichealthontario.ca)
  • Heating, Ventilation and Air Conditioning (publichealthontario.ca)
• Avoid direct air flow around people’s breathing zones to reduce respiratory droplets being dispersed from person to person. Rather than air flow at head level, options would be to direct the air upwards or to exhaust room air out of an open window while other open windows draw fresh air in.