Comparing Air Quality in University Classrooms Using Low-Cost Sensors

Air quality is fundamental to human health. While outdoor air quality has remained the focus of many studies, indoor air quality has only been studied extensively in the past few years due to the COVID-19 pandemic. Despite the recent surge of interest, indoor air quality remains to be overlooked and understudied. This is surprising, because according to the U.S. Environmental Protection Agency, people on average spend 90% of their time indoors. Consequently, it is essential to know the quality of the air one is breathing when indoors. One such place that indoor air quality needs more research on is in university classrooms. In these types of settings, students do not have a significant amount of control over the air that they are breathing, and may not even know what kinds of side effects this could have on their health and/or learning. In this study, we examine the air quality in three different classrooms at the University of Illinois at Urbana-Champaign over the course of the school year using Quant-AQ’s low-cost sensor, MODULAIR. Using this sensor, we analyze the mass concentrations of particulate matter, such as PM1, PM2.5, PM10, and the amounts of other important gasses such as CO, CO2, NO, NO2, and O3. By measuring these data, we then compare observed levels of aerosols and gasses to the recommended levels, ensuring safe air quality is present in the classrooms. With this study, we hope to encourage the use of low-cost air quality sensors in indoor environments, and help inform people on the importance of monitoring indoor air quality.