Passive Optimization of Indoor Thermal Comfort Using Bio-based Materials: An Experimental Study in a Classroom in Burkina Faso

Abstract

In the Sahel region, which is characterized by extreme temperatures and energy insecurity, improving thermal comfort in school buildings is a major challenge. This study evaluates the effectiveness of a bio-based construction solution integrated into the envelope of a typical school building in Burkina Faso. This solution is a bio-based eco-material made from plant aggregates (rice husks) and plant fibers (kapok) used as a false ceiling and wall coating. A dual approach was adopted: experimental measurements in situ during the hot season and dynamic thermal modeling using Python. The results show a reduction in maximum indoor temperature of up to 8°C, a thermal phase shift of approximately 5 hours, and a decrease of more than 57% in the intensity of thermal discomfort (>32°C) when the eco-material is used in combination with a false ceiling and wall coating. In addition, the theoretical cooling energy demand is reduced by 30%, highlighting the energy benefits of these materials in terms of energy efficiency. These performances, combined with the accessibility of local resources and ease of implementation, position these solutions as credible alternatives for the design of bioclimatic schools adapted to the Sahelian climate. The study also highlights limitations related to hygrothermal sustainability and calls for further work to assess the impact perceived by users and reproducibility on a large scale.