Indoor Air Quality Assessment Through IoT Sensor Technology: A Montreal–Qatar Case Study

Abstract

This study addresses the need for effective, real-time monitoring of indoor air quality, a critical factor for health and environmental well-being. The aim is to develop an affordable, Arduino-based IoT sensor system capable of continuous measurement of key air pollutants, including CO2, PM2.5, NO2, and VOCs. The system integrates multiple sensors and transmits data to an online server, where it is stored in a MySQL database for analysis and visualization. Validation studies conducted at Concordia University and Qatar University confirm the system’s accuracy and reliability, with discrepancies reduced to under 15% through calibration and adjustment techniques. Comparative analysis with commercial monitoring instruments reveals strong correlations and negligible deviations, supporting the system’s validity for real-time air quality monitoring. The system also includes a user-friendly interface that displays real-time data through intuitive charts and tables, along with an indoor air quality index to help users assess and address air pollution levels. The system demonstrates a 90% cost reduction versus commercial tools while maintaining a mean deviation of <15% across climatic extremes. Its combination of comprehensive sensors, data visualization tools, and an air quality index makes it an effective tool for environmental monitoring and decision-making.