Numerical Analysis of the Roof Slope Effect on the Building Thermal Comfort and the Need for Roofing Materials in Tropical Area

Roof is the most affected building envelope element by local climate changes such as solar radiation, rain, wind, etc. The design of a building's roof will have a significant impact on the building's thermal conditions and comfort. This study aims to numerically analyze and optimize the slope of a gable roof on an 8 m × 12 m residential building with 3 m walls located in a tropical climate region. The parameter analyzed in this parametric study on galvanized steel gable roofs is the slope angle impact in the interval between 150 to 450, with an angle increment at 50. The thermal aspect of the analyzed building is modeled numerically using the TRNSYS simulation tool coupled with CONTAM for aerodynamic modeling. The results showed that the greater the roof slope angle, the more comfortable the room condition was due to the amount of heat release that occurred in the attic zone before penetration into the occupation zone. Otherwise, the greater the angle of inclination, the greater the roof geometry that leads to construction material addition for the frame and roof covering. Therefore, it is necessary to perform numerical analysis to determine the optimal slope of a gable roof that provides maximum thermal comfort in a room with low roofing material requirements. Analysis and optimization of convective heat dissipation from the attic zone through natural ventilation or infiltration to reduce indoor thermal gain is an outlook for further research.