Analysis of the Influence of Envelope Heat Gain on Hygrothermal Comfort in Tropical Housing: The Case of Benin

The current construction of residential buildings in Benin neglects the importance of thermal insulation of their envelopes. Instead, it relies on active systems as a solution to mitigate over-consumption of electrical energy and guarantee a certain level of thermal comfort inside these buildings. It should be noted that Beninese architects are generally unfamiliar with these thermal aspects. The main aim of this study is to assess the effects of thermal insulation on walls and roof, determine the optimum thickness of insulating materials, and integrate a controlled mechanical ventilation system to improve thermal comfort in a humid tropical climate. The investigations were carried out on an example of a typical residential building located in Cotonou, Benin, with precise geographical coordinates (latitude 6°38' North, longitude 2°34' East). To analyze the thermal behavior of this building, a series of dynamic thermal simulations were carried out using TRNSYS software, which was used both to model the building structure and to run the various simulations. The results of this study revealed that thermal insulation of the walls and roof, using polystyrene, significantly reduced the need for air conditioning. What's more, the integration of a controlled mechanical ventilation system not only ensured indoor air quality, but also helped regulate indoor humidity, reducing it from 67% to 76%.