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Ventilation
Detailed school ventilation guidance and checklists are provided in 2021:B14 School Ventilation.
Building on what has been achieved to date, for the 2021-22 school year, school boards are expected to continue optimizing air quality in classrooms and learning environments through improving ventilation and/or filtration. This is a key element in the multiple protective strategies to support healthy and safe learning environments for students and staff.
School boards are required to ensure ventilation systems in all schools are inspected and in good working order prior to the start of the school year and continue inspection and maintenance throughout year. Inspections can be done internally by school board staff or by third parties.
School boards are expected to continue using and/or adopt ventilation improvement measures that are applicable to schools’ existing ventilation systems.
For schools with full mechanical ventilation, school boards are expected to:
- use the highest-grade filters possible, preferably MERV 13 filters
- undertake frequent filter changes through the school year
- operate ventilation systems 2 hours or more before and after school occupancy
- calibrate HVAC systems for maximum air flow and increased fresh air intake
This guidance also applies to schools with mechanical ventilation for parts of schools, such as additions.
For schools or parts of schools without mechanical ventilation, school boards are expected to place standalone high efficiency particulate air (HEPA) filter units in all classrooms and learning environments, including classrooms, gyms, libraries, lunchrooms, child care spaces, administrative spaces and portables with no or poor mechanical ventilation, before students return to class. These units ensure particle filtration of air and improve air exchange. These units must be sized for the classroom or learning environment that is being used. In larger classrooms and learning environments, more than one HEPA unit may be required.
For schools with mechanical ventilation, school boards are expected to place a standalone HEPA filter unit in every occupied full-day kindergarten classroom as an additional health and safety measure to recognize that junior and senior kindergarten students are not masked in the classroom.
In addition, school boards are encouraged to support outdoor education where possible, and open windows where this augments ventilation for classrooms and learning environments.
Building on improvements made to ventilation in schools over the past year, school boards are expected to continue to work with qualified persons to plan for and continue to make upgrades to improve ventilation infrastructure. Projects should be prioritized to meet appropriate minimum ventilation guidelines from the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) Standard 62.1-2019