CO2 concentration in six schools located in Palma–a comparative evaluation

Abstract

In developed countries, children spend between 25% and 30% of the time inside schools, having a direct impact on their health, well-being and student performance. This study analyses indoor CO2 concentrations in six primary schools in Palma (Mallorca, Spain), representative of schools’ buildings constructed before 2000. In these schools, several classrooms are chosen to develop measurements of CO2 concentration, temperature and relative humidity, during the 2023–24 academic year. Results show high levels of CO2, in many cases exceeding recommended levels during 50% of the time of use. Additionally, temperature values are outside the comfort range during 60–100% of the time of use, depending on the classroom. This study aims to reveal the high concentrations of CO2 recorded in schools in Palma, as well as the values of indoor temperature and relative humidity, with the aim of contributing to the modification of regulations to improve the indoor conditions. In this context, it is important to consider the m3/person ratio in regulations but also to study the ventilation efficiency, as well as to pursue an integrated rehabilitation of school facilities. These findings underscore the urgent need for policy interventions and building upgrades to ensure healthier and more effective learning environments for children. © 2025 Informa UK Limited, trading as Taylor & Francis Group.