4EvAirSense: a retrofittable, self-powered and maintenance-free LoRa wireless indoor air quality sensing platform for ventilation improvement enabling safe and healthy environments

The economic and social impact of Covid-19 is evident in the constraints placed on businesses, schools and various public and private indoor spaces with regards to occupancy and ensuring safe return-to-work strategies. Exhaled CO2 affects human health at levels as low as 1,000 ppm, commonly observed in crowded, poorly ventilated rooms. Many countries have or are setting maximum Permissible Exposure Limits. Covid-19 mitigation strategies also cite improved ventilation, regularly exchanging indoor air with fresh outdoor air, as key to reducing indoor airborne virus transmission.

Whilst the sophisticated ventilation systems can automatically manage IAQ, there is a clear opportunity to develop affordable technical solutions based on CO2 monitoring that support improvements to ventilation for the widest possible range of users. There is also clear Covid-19 economic impact mitigation in reducing the operating costs e.g. energy usage and system maintenance, by introducing more efficient ventilation control options that are retrofittable and have lower cost of installation and ownership than competing options.

This project develops an autonomous prototype wirelessly communicating self-powered CO2 sensor device beyond current state-of-the-art to enable effective ventilation control. Combining GSS's new ultra-low power NDIR CO2 sensor, LoRa wireless communication and Lightricity world-leading indoor PV along with further sensors (Temperature/Humidity/Pressure/Light -- for further IAQ information and device management) in a miniaturised package would deliver the world's first truly self-powered long-range wireless CO2 sensor nodes for ventilation control and occupancy determination.

With only one gateway per building and long wireless range (km), LoRa Wide Area Network saves the deployment cost of multiple gateways per building compared with SoA short-range wireless approaches (Wifi, BLE, EnOcean) enabling much easier installation, maintenance and better affordability to different types of users e.g. individuals, housing associations, residential care homes. It enables economic fit-and-forget retrofitting/upgrading of control or adjustment notification to facilities managers and allows care home and residential users to be notified for simple, practical actions like opening windows when air quality indicates insufficient ventilation. The project builds upon previous feasibility work powering a short-range CO2 wireless sensor using Lightricity PV and significantly extends functionality and capability beyond the state-of-the-art in wireless CO2 sensors.

The solution is sustainable through better ventilation control reducing wasted energy and using a renewable energy source (PV) to avoid environmental impact of battery waste. It is also inclusive in bringing ventilation control options and therefore health to the widest possible range of users.