Investigation into energy performance of a school building in a hot climate: Optimum of window-to-wall ratio

Global attention is currently focussed on developing techniques to improve the thermal performance of buildings to provide indoor comfort with minimum reliance on energy load. Several studies have investigated building facade, materials used and other factors involved in building design. The aim of this study is to examine the impact of thermal insulation, shading devices, window-to-wall ratio (WWR) and a combination of these factors in a prototype school building design in the warm climate city of Taif, Saudi Arabia. The study used various methods classified into two main phases. The first phase involved on-site observation where both thermal imaging and regular cameras were used to examine the influence of orientation on glazing as a baseline. The second phase involved advanced software investigations with 2D AutoCAD, 3D Revit and computer modelling for energy evaluation and daylight factor. A detailed framework was introduced to examine current school buildings and to improve the future designs of prototype school buildings. The study revealed that a combination of applying thermal insulation along with minimising WWR is required in existing buildings within hot and dry regions. Furthermore, it was recommended that WWR should not exceed 35%, 25% and 20% for northwest, southeast and southwest building facades, respectively.