Solutions to ventilate learning spaces: a review of current CO2 sensors for IoT systems

Over the past year, the implementation of IoT systems for monitoring CO2 in learning spaces has accelerated. The urgency caused by the pandemic has motivated the creation of multiple maker communities made up of teachers, researchers, students, parents, and volunteers in general to act together on the implementation of IoT systems monitoring CO2 in learning spaces. This article explores this topic contributing in three key aspects: First, the results of a review of scientific articles presenting IoT systems to ventilate learning spaces are described. Their CO2 sensors are characterized and classified considering their main features. Second, a European project is presented that aims at promoting environmental awareness exploring the effects of plants in learning spaces measuring CO2 with IoT systems installed in smart pots. Third, the main lessons learned are summarized and suggestions for future implementations are suggested. These results imply a relevant base knowledge towards facilitating the implementation of effective IoT systems to fulfill ventilation protocols in learning spaces.