CO2 and ventilation monitoring in schools: a practical guide
A classroom full of students fills up with exhaled CO2 within a lesson if the air isn't renewed. A CO2 sensor turns that into a number you can act on: it tells you when to open the windows and which rooms ventilate worst. This guide covers what to measure, how many sensors you need, how they connect and what a real deployment across 120 schools looked like.
What to measure in a classroom
- CO2: the usual indicator of ventilation: the higher it climbs, the less the air in the room is being renewed.
- Temperature: to see whether ventilating is making the room too cold or too hot and to balance the two.
- Humidity: completes the picture of comfort in the room.
Alert thresholds are configurable. Each school or administration sets its own according to the guidelines it follows.
How many sensors does a school need?
It depends on what you want to know. To control ventilation room by room, you need one sensor in each classroom you want to follow. To get a picture of the school and decide where to act, a few sensors in representative rooms are enough. In the Canary Islands, 240 sensors were installed in 120 schools: two per school.
4G, LoRaWAN or WiFi?
- 4G: each sensor has its own mobile connection and doesn't depend on the school's network or IT team. With solar charging, it is the option used in the Canary Islands.
- LoRaWAN: sensors send data to a gateway. The platform receives it through external network servers such as The Things Stack, LORIOT, ThingPark X or ChirpStack.
- WiFi: WiFi devices send data directly over MQTT or HTTP, if the school network allows it.
The choice of sensor and connectivity is made for each project. See also: LoRaWAN platform.
Real case: 120 schools in the Canary Islands
Gesplan, for the Government of the Canary Islands, deployed 240 solar-powered 4G sensors (Makerfabs 4G LTE Air Monitor) in 120 schools across the 7 islands. The installation took 18 working days, against the 79 planned. Each school has its own dashboard with a public link: 120 dashboards in total.
Who installs it
The installation can be done by the company that already maintains the schools, an integrator or one of our 35+ partners. We configure the platform, the alerts and the dashboards. Cloud Studio IoT runs on AWS (Frankfurt for Europe, United States for the rest of the world) and can also be installed on-premise.
