Distributed LoRa based CO(2) monitoring network – A standalone open source system for contagion prevention by controlled ventilation

In the face of a global pandemic, such as that caused by the SARS-CoV-2 virus, the prevention of new infections is essential to stop the spread and ultimately return to normality. In addition to wearing masks and maintaining safe distances, regular ventilation in enclosed spaces where several people are gathered has proven to be an effective protective measure as advised by the World Health Organization. Additionally, as has been shown in a recent study of other airborne viruses, there is a strong correlation between the CO(2)level and aerosol content in a confined space under the assumption humans are the only CO(2)source. This can be exploited by means of a low-cost infrared CO(2)sensor to indirectly monitor the aerosol content and to provide targeted ventilation if predefined thresholds are exceeded. The distributed CO(2)monitoring network presented in this paper extends that idea and provides an inexpensive, comprehensive and modular monitoring network based on readily available components and 3D printing. By using a long-range communication link (LoRa) to centrally collect the real-time CO(2)concentration in a multitude of rooms, this network is particularly suitable for larger building complexes such as kindergartens, schools and universities without requiring partial or even full WLAN coverage.