Nils Gustavsson, President at the Indoor Air Hygiene Institute, looks at three key areas schools can address in terms of indoor air quality to further safeguard against Covid-19 risks

Children returning to classroooms

As schools in the U.S. prepare to open theirdoors this fall, there’s major concern that vaccination levels in the country are not enough to mitigate the risks of spreading and contracting the Covid-19 virus – particularly among unvaccinated younger students and in light of the fact the Delta variant is having an impact on this age group. In-person learning is of course the favorable option,  but the anxiety faced by the children, parents and teachers must be faced head on and everything possible done to ensure that once open, schools can stay open.

The Centers for Disease Control and Prevention (CDC) published updated guidelines in July of this year that outlined a wide variety of measures for K-12 school students returning in the fall – including the wearing of masks for all children over the age of two who have not been fully vaccinated, physical distancing of at least three feet in classroom situations, and screening testing, ventilation, handwashing and respiratory etiquette (essentially covering your mouth with a tissue when you cough or sneeze).

While there is a mention of ventilation, the Indoor Air Hygiene Institute (The Institute) believes far more emphasis must be placed on indoor air hygiene as a whole in educational settings, and sets out three key areas that schools can focus on right away to further mitigate the risk of Covid-19 and to increase the level of safety within the school environment.

1. Ensure MERV-13 level filtration or higher, and that your system is running

Filtration describes the replaceable media inside HVAC equipment that removes particulate contaminants, either from outside air or from recirculated indoor air. The process of filtration captures particles and pathogens, but does not necessarily kill pathogens, and as filters come in a wide range of efficiencies, effectiveness levels vary. Ultimately, the higher the efficiency, the more the media captures. Efficiency is measured as a MERV rating (Minimum Efficiency Reporting Values), and in order to remove significant indoor air quality dangers, the Institute recommends that MERV 13 or higher should be used in schools’ HVAC systems. The ideal filter to address very small particles, classified by the EPA as PM2.5, is referred to as a HEPA filter.  These filters capture a minimum of 99.97% of the particles and pathogens in the air.  Very few HVAC systems can handle the resistance created by HEPA filters, therefore portable air purifiers with HEPA filtration should be considered to achieve this level of protection. These are usually standalone units that can be placed in the classroom (make sure they are placed in open areas with good airflow).

Lastly, filters only work when air is pushed through them. This is an obvious statement, but systems that only run while cooling or heating the air, and then remain off the rest of the time, miss the opportunity for continuous filtration of the air. Make sure the HVAC system is running continuously while the building is occupied, and make sure the air purifiers are set on their highest setting while the students are in the classroom. The goal is to push as much air through the filters as possible, continuously.

2. Understand your high-concentration locations

A thorough indoor air hygiene evaluation of your school will allow officials to learn how to mitigate risk in the best possible manner depending on the activities in each location. Often, the focus is centred on the HVAC system and what it can do. This is a critical understanding, but what is many times ignored is to understand what the indoor air quality is like where the people are actually located. Running the school HVAC system optimally for temperature does not mean that the air quality is safer and healthier where the students and teachers are located, therefore it is key to know how the air quality behaves in different areas in order to formulate an effective strategy to optimize it.

High occupancy spaces must be a priority, as classrooms, lunch rooms, and gymnasiums are often up to four times more crowded than an office space and are where students and teachers spend the majority of their days. It is this high concentration of people that increases the possibility of virus transmission, and without significant mitigation strategies in place that risk will remain. One way to make a significant impact is to ventilate – or bring outside air into the space to dilute any viruses that are in the air. Ventilation could be as simple as opening an exterior door or window to allow fresh air to flow through the space. If that is not a good option due to climate or outside concerns, consider changing how the HVAC system is run to allow for outside air to be brought into your space.

Ventilation is not only important for reducing virus transmission, but also because fresh air lowers carbon dioxide in the air. Reduced CO2 levels are linked to increased alertness and productivity – which is critical after a year of learning loss due to pandemic closures. Of course, no two schools will be the same, therefore it is imperative that a proactive, continuous approach to air hygiene is adopted going forward since the air quality is constantly changing based on what is happening in the space.

3. Install continuous monitoring of indoor air hygiene

Air hygiene is constantly changing and the only way to know the quality of the air is through real time data and monitoring. By reviewing this data consistently, an indoor air hygiene action plan can be developed to ensure occupants are breathing optimal air all the time. To this end, the Institute is able to work with schools to measure the quality of the air and provide specific recommendations to make the air safer for all students and teachers.   The Inside Advantage™ Certification Program is an outcome-based, extensive diagnostics process where indoor air hygienists measure the quality of the air real-time and help schools to improve it through data-driven scientific recommendations. The certification is based on indoor air hygiene metrics that are actively monitored, and managed to have a much more positive impact on student and staff health, wellness and productivity.Perhaps most importantly, monitoring and assessing the air in your school with the help of a Hygienist allows you to understand what, if anything, needs to be done, instead of spending a lot of money on recommended products that may or may not be needed – or worse, may not be effective. The air management industry has unfortunately seen technologies being offered with big promises but little proof. Be aware.

For further information on how the Indoor Air Hygiene Institute can help your school open and stay open, please contact:

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