Ventilation is the key to helping students, staff and families stay safe
Thoughts on SFUSD’s Return Safely to School Together Plan
Last night district staff shared a plan for bringing students back to schools for in-person learning. Click the following links to see the proposed plan and presentation. (When the conversation becomes available via SFGovTV I will post it as well below.)
In reviewing the presentation, I made a request at the meeting for the plan to incorporate several revisions focused on increasing student and staff safety in returning to schools in the following areas: ventilation, masking and family agreements in following preventative measures, and testing availability.
Anyone who watched our hours-long discussion on school reopening last night knows each topic is deserving of its own lengthy discussion. In the interest of educating the public, I wanted to share my recommendations and our Board’s incorporated input into the final plan which we will approve next week.
Ventilation is the key to preventing the spread of Covid-19
I believe SFUSD’s ventilation plans must address air exchange rates ensure all classrooms meet health and safety recommendations recommended by health experts. (The World Health Organization recommends six times per hour, and the SF Department of Public Health shared a recommendation of four times per hour at the last Joint Select Meeting on Friday, November 13, 2020. See my discussion with SF Department of Public Health staff starting at 58:05.)
What experts say…
I’ve been following Dr. Eric Feigl-Ding, a noted epidemiologist & health economist epidemiologist, on Twitter. He has shared these videos on and microdroplets and they illustrate how Covid-19 can spread in unventilated spaces.
The World Health Organization (WHO) has also been sharing information on the importance of ventilation. In this five-minute video, researchers share how ventilation can help make indoor spaces more safe. They recommend classrooms go beyond “passive ventilation” such as opening doors and windows as the district plan recommends and mechanical ventilation to increase airflow.
As the Rhode Island Department of Public Health clearly states on it’s website:
“One way to measure ventilation is to figure out how often the air in a space is completely replaced. This is called Air Changes per Hour (ACH). In a 30-foot by 30-foot classroom that has 25 students in it, the air should be replaced at least every 15 minutes, which equals an ACH of 4. If the air is replaced at least every 10 minutes, there is an ACH of 6, which is better. There is not a standard for ACH, but we do know that a higher ACH lowers the risk of disease spreading through the air.”
“Preventing the Spread of COVID-19 By Circulating Air in Schools and Other Buildings”, State of Rhode Island Department of Public Health
Due to our temperate climate in San Francisco, the majority of our schools rely on “passive ventilation” and are not built to meet modern HVAC codes. Nonetheless, experts are saying that as long as it isn’t too cold, in-window box fans can prove to be an inexpensive option for meeting the Air Changes per Hour (ACH) recommended by health experts for indoor spaces. Where money, space and resources allow, it is also important to continue to research options for outdoor learning on our school sites.
In this video Dr. Feigl-Ding has also discussed how “ventilation is the key” to Covid-19 prevention and shared this video illustrating the effectiveness of cross-ventilation fans on ACH.
Recommendations and Discussion
In our discussion last night, I shared that I had reached out to building engineers in the private sector with expertise in HVAC systems to learn about potential options for increasing ACH rates in our schools. They told me window-fit fans are a relatively low cost “fix” that wouldn’t require much electricity (so as not to overload electrical systems). In speaking with the district Cheif Facilities Officer, Dawn Kamalanation, she agreed that window-fit fans are fairly easy to install and do not require the time or money required of more permanent HVAC upgrades. Some classrooms may have window conditions that require more work than others to install them securely, so in addition to the cost of fans and materials, there would also be labor costs involved which will require an RFP process and investments from the City and philantropic partners.
Based on this knowledge, I proposed the following enhancements to the district reopening plan:
- Provide mechanical ventilation in all schools to ensure air change rates are met in all classrooms. (In practice, this would look like one set of “window fit” fans per classroom and/or office, with one fan blowing air in from the outside, and one fan blowing out.)
- Develop a plan for outdoor classrooms in spring (especially for upper elementary, middle, and high school) to expand safety and capacity.
- Develop a plan for upgrades to HVAC systems at all school sites in the fall and as bond programs allow.
While many Commissioners expressed support for enhanced safety provided by mechanical ventilation, they also shared concerns about making school reopening deadlines dependent on the above recommendations due to the time and money and the number of schools involved. (We have over 70 elementary schools in SFUSD.) While these requirements won’t be included as a requirement for approval of the final plan, there was strong support from the Board.
I believe we can implement higher ventilation standards while still meeting our reopening timeline goals if we develop strong partnerships with City and philanthropic partners. Commissioner Moliga and I will bring this conversation to our conversation at the Joint Select Committee this coming Friday, December 11th, 2020.
In order to make this a reality for all our educators, staff and especially students from communities of color who may who want to return but are fearful about safety, we will need the strong advocacy from family and community leaders. Please share your support for safe, well-ventilated schools!
That’s not all!
While ventilation is an extremely important way we can keep our kids, staff and ultimately families safe, it is by no means the only measure. As many health experts caution us, there are no safety measures proved to be 100% effective in preventing the spread of Covid-19. This is why they recommend utilizing multiple layers of safety measures be implemented. The Swiss Cheese Model is a helpful way to illustrate the ways that combining safety practices increases our ability to prevent community spread.
This is why, in addition to ventilation, the CA and SF Department of Public Health also require districts to follow other safety practices in reopening schools. These practices include: safe-social distancing, masking and practicing healthy home habits, as well as increased testing and monitoring of symptoms.
Stay tuned tomorrow as I continue to share my recommendation on ways to enhance safe in-person learning.
