CO2 Monitor Reference Design

Sensirion provides a low-cost CO2 monitor reference design to enable IoT and HVAC companies to rapidly develop their own CO2 monitor solution. Due to the pandemic, there is an increased demand to measure indoor CO2 concentrations. Scientific studies indicate that COVID-19 is airborne resulting in an increasing demand to keep CO2 concentrations in schools, offices and other crowded indoor environments monitored. Simple CO2 monitors help to know when it's time to ventilate the room.
Here is an overview of the topics on this website:
- Use Case: CO2 Monitor
- CO2 Monitor App
- Advantages of Using the CO2 Monitor Reference Design
- Contact Us: How to Go from Reference Design to a Product?
- Maker Tutorial: Create Your Own CO2 Monitor
Why to Measure CO2 Indoors?
Too much CO2 in the air results in a stuffy climate, decreasing occupant work performance and increasing risk of infection with viruses. Since indoor CO2 is mostly emitted from humans, there is a correlation between indoor CO2 concentration and exhaled air. Exhaled air contains human aerosols, which might carry viruses like COVID-19. Therefore, CO2 concentration can be used as a trigger to ventilate for lower airborne virus infection risks. Especially in winter, or when outside air pollution levels are high, it is beneficial for occupants to ventilate only as needed. CO2 monitors help to trigger ventilation and to create awareness for efficient ventilation routines, especially in schools without automated ventilation systems.
Use Case: CO2 Monitor

Efficient ventilation, an increase in productivity and the possibility of reducing virus infection: CO2 monitors can be widely used in homes, schools, institutions, companies and many more. A CO2 monitor, which works like a traffic light offers a simple but user-friendly solution.
The CO2 monitor comes already calibrated and only needs to be connected to electricity. The LED display can be used immediately for CO2 monitoring. Whenever possible, the CO2 monitor should be placed at eye level and not directly next to windows or people.
The LED light then informs occpupants via three color levels about the CO2 concentration level in their room. The top part of the CO2 monitor is made of transparent plastic and provides a well visible light indication.
The standard thresholds are as follows:
- Green: <1000 ppm
- Yellow: 1000 - 1600 ppm
- Red: > 1600 ppm
Users who need more detailed information, can use the CO2 monitoring app to read out the precise concentration via Bluetooth.
Features
- Enables efficient ventilation thanks to intuitive light indication – no complicated displays
- Advanced CO2 history and data download via app
- Wall- or tabletop mounting, both possible
- USB powered - multiple power sources possible (e.g. powerbank, laptop, USB AC adapter etc.)
- Highest CO2 measurement accuracy with Sensirion's established SCD30 CO2 sensor: ±(30 ppm + 3% of measured value)




CO2 Monitor App

The CO2 monitor reference design was created for companies, which like to develop their own commercial CO2 monitor relying on their individual supply chains. It is not intended as an Arduino-based maker project, but as the foundation for developing a robust high-volume low-cost CO2 monitor.
Sensirion provides the mechanical design and electrical design for companies with the intention to make a commercial CO2 monitor on request.
Features of the CO2 Monitoring App
- Displays precise real-time CO2 concentration
- Three months of historic data (time chart: +8000 data points)
- Data export & download from app
- Manage multiple monitors in one app
- Set thresholds of LED color via app
- Set light intensity of LED via app
Advantages of Using the CO2 Monitor Reference Design

How to Go from Reference Design to a Product?
Please reach out to us to discuss the next steps!
Maker Tutorial: Create Your Own CO2 Monitor

For our maker community we gladly provide a tutorial enabling the setup of a CO2 monitor using our SCD30 CO2 sensor for sending CO2 measurements via Bluetooth to nearby phones. In this tutorial we guide you through all necessary steps to build your own monitor. Furthermore, we provide a compatible app for Android and iOS.
Learn more about the hardware, software and monitor setup and kick-start your own project now.
Check out the tutorial here.