Optimizing sensor placement in classrooms: a focus on temperature, relative humidity and CO2

In developed countries, people spend most of their time indoors; therefore, indoor environmental quality has a direct impact on human health. Assessing indoor conditions requires the continuous monitoring of several parameters. In this context, the present study aims to analyze the influence of sensor placement on the monitoring of CO2 concentration, temperature and relative humidity in a primary school classroom. To this end, several sensors were installed in different locations within the classroom, and real-time data were collected for CO2 concentration, temperature and relative humidity. The results showed that CO2 measurements exhibited deviations from the mean ranging from 1% to 11% depending on sensor position, with the highest concentrations recorded near the students’ working area. In contrast, deviations in temperature and relative humidity were minimal, ranging between 1–3% and 0–5%, respectively. It is concluded that the most appropriate location for sensor placement in this type of study is on the teacher’s desk, as it allows for minimal interference with teaching activities, facilitates teacher supervision of the device, is positioned near the main emission source, ensures proper sensor operation, and yields representative data of the classroom environment in terms of CO2, temperature and relative humidity.