Most of us spend the vast majority of our lives indoors—close to 80% of our time.
Yet monitoring the quality of the air we breathe inside homes, schools, and workplaces has typically required expensive laboratory-grade equipment.
That’s now changing, thanks to a new low-cost sensor system developed by researchers at Concordia University and Qatar University.
The system, described in the journal Atmosphere, uses Arduino microcontrollers, small and inexpensive computers often used for do-it-yourself electronics projects.
When connected to a set of air-quality sensors, the microcontrollers can measure carbon dioxide, nitrogen dioxide, and fine particles—pollutants that affect everything from cognitive performance to lung health.
The devices also monitor volatile organic compounds (VOCs), including gases like benzene, formaldehyde, and acetone, which can seep into the air from cleaning supplies, paint, furniture, or even car exhaust that drifts indoors.
What makes this system especially powerful is how it delivers the data.
All the information is transmitted wirelessly to an online dashboard, where live charts and air quality indexes are updated in real time.
This means that users can immediately see how indoor air responds to daily activities, such as cooking, cleaning, or even the flow of outdoor traffic.
To test whether the low-cost sensors could stand up to real-world conditions, the researchers ran experiments in two very different environments: the cold, humid winters of Montreal and the hot, dusty climate of Doha.
Many budget monitors lose accuracy when conditions shift, but this system consistently performed within 15% of professional-grade instruments. It was also quick to react to sudden changes, whether from smoke in the kitchen or traffic outside during rush hour.
By proving that a low-cost, Arduino-based setup can track air quality so reliably, the project opens the door to widespread monitoring in schools, offices, and public buildings around the world.
Instead of relying on expensive and centralized testing, organizations could deploy affordable networks of sensors to identify problems early and take steps to improve air quality before it harms people’s health.
For the researchers, the goal is not just to make air quality data more accessible but also to help people understand how their daily activities affect the air they breathe.
With systems like this, the invisible can become visible—and that could lead to healthier indoor spaces for everyone.
Source: Concordia University.
