Humans spend about 80 per cent of our time indoors, but keeping track of the air we breathe usually requires expensive lab-grade equipment. Researchers at Concordia and Qatar University have created a low-cost sensor system that does the job just as well and in real time.
The devices are built on Arduino microcontrollers tiny, affordable computers often used in research and do-it-yourself projects. Hooked up to sensors, they measure carbon dioxide, fine particles and nitrogen dioxide. They also track volatile organic compounds (VOCs) like benzene, formaldehyde and acetone gases that can be released from paint, cleaning products or car exhaust.
Data is sent wirelessly to an online dashboard, where users can view live charts and air quality indexes.
System works across environmental conditions
To prove the system's reliability, the team tested it in two very different climates: Montreal's cold, humid winters and Doha's hot, dusty desert air. Many low-cost monitors struggle when conditions shift, but this system stayed accurate within 15 per cent of commercial instruments in both environments. It also responded quickly to real-world changes, like cooking smoke or rush-hour traffic.
By making indoor air monitoring both affordable and climate-resilient, the project could help schools, workplaces and public spaces worldwide spot problems faster and keep people healthier.
The paper builds on a 2023 Master of Science thesis by Zhihan Wang. Co-authors include Zhi Chen and Fariborz Haghighat, both professors in the Department Building, Civil and Environmental Engineering at the Gina Cody School of Engineering and Computer Science.
Imran Shahid at Qatar University and Zunaira Asif at the University of New Brunswick also contributed.
Read the cited paper: "Indoor Air Assessment Through IoT Sensor Technology: A Montreal-Qatar Case Study."
The study was published in the journal Atmosphere.
