Comparative Assessment of The Thermal Comfort in Naturally Evolving Buildings in Hot and Dry Sahelian Climate: Case of The City of Ouagadougou in Burkina Faso

Abstract

Thermal comfort/stress depends on the balance of thermal energy on the human body. This balance is influenced by physical activity, clothing, and environmental parameters such as hygrothermal conditions of the ambiance and hygrothermal performances of the shelter's envelope. To better consider the bioclimatic conception of buildings in a hot and dry climatic context, thermal comfort assessment tools allow to decide on the feelings of the occupants of naturally evolving buildings. This paper assesses the thermal perception using three methods, namely the thermal sensation of vote (TSV), the Predicted Mean Vote (PMVe) and the tool specially developed for the hot and dry climate: case of Burkina Faso (CAT_BF). To do this, a survey was carried out on the thermal perception of the occupants of naturally evolving housing. At the same time, the thermal parameters were measured made it possible to obtain values of physical parameters such as air temperature, radiant temperature, relative humidity, air speed and quantities related to the individual such as metabolism and clothing level. The studies are based on the thermal sensations of individuals in the 720 dwellings at 2iE Kamboinsé, a locality located in Ouagadougou in central Burkina Faso, over which they had full control of the interior atmosphere. As the PMVe method was developed for conditioned buildings, a corrective factor (e) was used to adapt it to the atmosphere of buildings in free evolution. The thermal comfort assessment tool based on the adaptive model is adapted to freely evolving buildings in Burkina Faso. The study shows that TSV gives 52% of thermal comfort, while the PMVe predicts 52.7% comfort index; against the 52.5% predicted by the CAT_BF. The results indicate that the PMVe method with the expectation factor of 0.5; as well as the CAT_BF approximately predict the real perception of the thermal comfort of the occupants of the naturally evolution buildings.