Thread by @jeffgilchrist

COVID-19: Ventilation and filtration in Ontario schools

The Ontario government previously announced that they would be adding HEPA filters to classrooms that did not have mechanical ventilation. They released memo B14 ( efis.fma.csc.gov.on.ca/faab/Memos/B20… ) to explain:
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- Updated ventilation best practice guidance
- Details of the investment in and approach to allocating standalone HEPA filter units
- Introduction of a standardized school ventilation report.
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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 the year. 3/

For schools with mechanical ventilation they are expected to:
- use the highest-grade filters possible, preferably MERV 13
- undertake frequent filter changes through the school year
- operate ventilation systems 2 hours or more before and after school occupancy
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- calibrate HVAC systems for maximum air flow and increased fresh air intake.

Schools or parts of schools without mechanical ventilation are required to place standalone HEPA filter units before students return to class. 5/

This is for all occupied learning environments including gyms, lunchrooms, etc. The units must be sized for the classroom and may require more than one HEPA unit. 6/

For schools with mechanical ventilation, schools must also place HEPA filter units in classrooms with JK/SK kindergarten classes as an additional health and safety measure since JK-SK students are not masked in the classroom. 7/

"In addition, school boards are encouraged to support outdoor education, where possible, and open windows where this augments ventilation for classrooms and learning environments." 8/

The province is investing up to $25M for the purchase of HEPA filter units but has already procured 20,000 HEPA filter units that are ready for immediate deployment to schools to help ensure they are in place before the start of the school year. 9/

In addition for the 2021-22 school year, the ministry is also launching a standardized ventilation report. This report will be available on school board websites to enhance transparency for communities, students, parents, and staff. 10/

Recently, memo B16 ( efis.fma.csc.gov.on.ca/faab/Memos/B20… ) was released which details information in the report including:
- School Board Ventilation Strategy
- School Board Ventilation Investments
- School-level Ventilation and Filtration Measures
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You can see the template of the report in the Appendices of the memo. All school boards must post this report to their board websites by Sept. 3, 2021. 12/

David Elfstrom, a Professional Engineer working in air quality has some concerns about proper HEPA sizing for ventilation equity (

https://twitter.com/davidelfstrom/status/1427270430155476992?s=21

). 13/

You need to properly size HEPA filtering for the clean air flow delivered to the volume of the classroom, take into account mixing, and noise limits which requires professional oversight. 14/

Adding a HEPA filter to every classroom may be equal, but in order to provide equitable ventilation, non-mechanically ventilated classrooms would need multiple HEPA units, likely running on medium speed so that noise is not too loud and not interfere with class learning. 15/

Without professional oversight, some schools in other areas purchased HEPA filter units that were so big and noisy; they had to turn them off when students were present so they could hear the teacher, completely negating the purpose of the HEPA filters. 16/

This graphic is a great example showing the difference between equality, equity, and justice. For justice, the province would need to fund capital repairs to fix ventilation in all the schools. 17/

Please remember that good ventilation is not just for COVID-19, it helps reduce all airborne pathogens, will reduce absenteeism, and increases cognitive abilities of students to help them learn more. Investments in this area will have continuously ongoing benefits. 18/