The Center for Disease Control and Prevention recently announced a comprehensive, science-based plan for getting students back to school. The new guidelines highlight evidence on how schools can reopen safely with layered mitigation measures.
While certainly a step in the right direction, the plan is notably lacking recommendations around improved ventilation: specifically, the guideline doesn’t do enough to clearly explain when, where, and how to improve ventilation in indoor spaces. Notably absent are recommendations for improving ventilation in classrooms, a critical safeguard in protecting teachers and students now that the coronavirus is known to be carried by tiny airborne particles that can linger in the air (we discuss long-range transmission in an earlier post).
Why should schools consider improving ventilation as they bring students back to school?
Over the past ten months, the global scientific community has learned much more about how the virus spreads–it’s airborne. One of the biggest weapons against an airborne contagion like COVID-19 is well ventilated indoor environments.
Increasing ventilation is also crucial in more than just nurses’ offices; in fact, all higher occupancy spaces like classrooms and cafeterias would substantially benefit from improved ventilation. However, the new CDC guidelines don’t define proper ventilation or specify how to achieve it.
So, what is ventilation?
Ventilation recommendations are included in CDC’s Considerations for Operating Schools during COVID-19. First, let’s take a minute to define what ventilation is, especially in concern to schools and building infrastructure. Ventilation is the intentional introduction of fresh air into an indoor space, like a classroom, while stale or contaminated air is removed. Simply, ventilation maintains air quality in an indoor space.
There are three methods used to ventilate a building: natural, mechanical, and hybrid ventilation (where both natural and mechanical ventilation methods are used).
What is natural ventilation?
Natural forces drive outdoor air through purpose-built building openings such as windows and doors. This natural ventilation of buildings depends on the climate, building design, and human behavior.
What is mechanical ventilation?
Mechanical fans, installed directly in windows, walls, or air ducts, drive mechanical ventilation. Mechanical ventilation encompasses residential and commercial HVAC systems, consumer-grade air purifiers, and industrial air purification systems that quickly filter massive amounts of air.
What is hybrid ventilation?
When natural ventilation alone is not suitable, installing portable ventilation systems can increase ventilation rates in rooms where needed.
How should schools manage ventilation when open for in-person learning?
The guide advises schools to consider ventilation system upgrades to increase clean air delivery and dilute potential contaminants in the school. Specifically, the CDC recommends that schools need to focus on the following layered mitigation strategies, including:
- Consistent and correct use of masks
- Physical distancing (staying at least 6 feet apart)
- Hand hygiene and respiratory etiquette
- Cleaning and disinfection
- Proper ventilation, including the use of portable high-efficiency particulate air (HEPA) systems to help enhance air cleaning
- Contact tracing in collaboration with the state or local health department
PPE and administrative controls form part of a holistic, multi-pronged approach to risk mitigation. However, tactics such as hand washing, masks, and social distancing, while relatively inexpensive to implement, are less reliable when used independently.
Why? Because people, and particularly younger students, are unpredictable. Engineering controls like ventilation and filtration must receive more emphasis and importance because machines won’t get sloppy, become distracted, or ignore the rules.
Portable HEPA air filtration systems are among the most affordable, effective, and easiest options to achieve proper ventilation in classrooms and schools across the country and should feature prominently in strategies for safely reopening schools.
Need help putting together a plan to reopen your school to teachers and students safely? By increasing ventilation rates through TRUE HEPA filtration, you can increase peace of mind for your students, parents, and staff.
Let us help configure your space. Talk to an expert.