Analysis of the Effects of Passive Design for Improving Building’s Hygrothermal Comfort in the Sahelian Climate

The present study aims to analyzse alternative passive design solutions for enhancing building energy and hygrothermal efficiency in the Sahelian zone. To achieve this, a model representing a standard single-storey cement-hollow block dwelling building and its relevant parameters was input into EnergyPlus, combined with OpenStudio or SketchUp. Scenarios were then analyzed to evaluate the effects of roof solar reflectivity, wall external insulation, natural ventilation, and their combined options. First, the base case, serving as a reference model, was validated using measured and simulated temperatures by calculating the scientific criteria, such as the NBME and CVRMSE coefficients recommended by the ASHRAE and IPVM standards. Additionally, the numerical simulation was used to compare interior temperatures, discomfort hours, thermal parameters, and the hygrothermal index (IHT) across seven cases studied. The reference model simulation indicated that cement-based hollow blocks are less effective for building envelopes in the Sahelian climate, with 51.48% discomfort hours and an IHT of 1.6, as shown in the Givoni diagram. The results revealed that the wall external insulation was the most effective passive solution, with 56% of comfort hours and an IHT of 0.7, which indicates the expected position of the model within the hygrothermal comfort zone of the Sahelian climate. Combining passive strategies yields the best scenario, resulting in a 28.25% reduction in annual total discomfort hours compared to the base case. These simulations demonstrated the effectiveness of accessible passive design solutions applicable in dwelling construction for the sustainable development of countries in the Sahelian climate.