Back to School — Improving Indoor Air Quality in the Classroom

A 2007 report from the Centers for Disease Control (CDC) reports that 12.8 million school days were missed by students in the US as the result of allergies and asthma. A critical part of the learning process is having an indoor air environment that is conducive for learning/teaching particularly if that environment is resulting in student absences.

What is needed is proper air conditioning. I am not referring to just cooling the air but conditioning the air to maintain the temperature, humidity, low airborne particle count (i.e. few dust and pollen particles), and proper ventilation. Ventilation is huge as it prevents stale air that builds up as a result of increased levels of carbon dioxide and volatile organic compounds (VOC's). VOC's are dangerous gases that come from sources like glue, magic markers, and printers.

Here are our recommendations for good indoor air quality in the classroom:

1. Source control — remove any sources of indoor air pollution. If there are buses idling outside the window make sure the windows are closed. If there is glue, paint, markers or other substances to produce gases, ensure that these are closed when not in use. It would be better to have these stored in an area away from the classroom.
2. Ventilation — ensure the HVAC system is properly circulating in fresh air and at a comfortable temperature and humidity level. Humidity levels should be between 35% and 50%. If they get above 65% then mold can grow based upon the moisture that is in the air.
3. Filtration — HEPA filters are recommended as the best technology to remove the airborne particles. These can be dust, mold or pollen that trigger allergies and asthma as well bacteria. An HVAC system typically will not have HEPA filtration since they are not sized to overcome the extra resistance that exists with these filters. Essentially, the HEPA filteris a dense filter that requires stronger air flow than the HVAC system can support.