The effect of openings ratio and wall thickness on energy performance in educational buildings

The building envelope is the boundary between the outer and inner spaces and it is considered as the most significant part in the process of preservation of internal spaces cooling energy consumption. In this context, it is argued that the weakest point in the envelope with the highest transmittance of thermal energy into and out of the internal spaces is the openings (windows and doors) which are affected by many factors such as their ratio, material thermal properties and construction. Therefore, this study sheds light on the alternatives of the envelope design generated with the help of a computer-based simulation tool, Design-Builder, as it has great possibilities for creating simulated scenarios for a specific building or space by linking these scenarios with specific changes in the building parameters. Thus, the study will focus on creating different scenarios for a selected classroom in the College of Arts and Design at Princess Nourah bint Abdulrahman University (Riyadh, KSA), with the aim of associating the openings ratios (20%, 30%, 50%, 100%) with wall thickness (12 cm, 25 cm solid brick, 25 cm hollow brick) and energy consumption. Optimum alternatives for the opening ratio and construction materials with the lowest cooling loads during working hours are proposed.