Impact of window shading on the thermal performance of residential buildings of different forms in Jordan

Introduction: Window shading is considered one of the most effective passive design approaches that improves indoor thermal performance, minimizing the usage of HVAC and reducing energy consumption. Purpose of the study: We aimed to investigate the impact of external window shading on thermal performance of three existing residential buildings having different forms (rectangular, L-shaped, and U-shaped) in hot-dry climate in Amman, Jordan. Methods: Three types of shading, namely: vertical, horizontal, and combined, of different lengths (0.75 m, 1.00 m, and 1.25 m) were introduced to the existing buildings. The effect of those types of shading was studied using the OpenStudio SketchUp 2020 plugin and EnergyPlus simulation program. Results: It was established that vertical shading slightly improves the indoor air temperature in all building forms, while horizontal shading and combined shading improve the thermal performance of buildings to a more significant extent. Combined shading of 1.25 m in length shows the optimum behavior in all buildings since it reduces the indoor air temperature in the range of 2.6–3.3°C. Besides, it improves thermal sensation, which seem to be closer to the comfort zone, by reducing the predicted mean vote (PMV) and predicted percentage of dissatisfied (PPD) values as compared with the baseline situation without shading. In addition, the rectangular building demonstrated the best response for shading by showing the largest reduction in the indoor air temperature.