Energy savings from the shading performance of devices in highly glazed multi-story office buildings in the tropical climates of China and India

Rapid urbanization in China and India has led to the widespread development of high-rise office buildings with highly glazed façades in tropical climates, increasing the need for energy-efficient design strategies. Exterior shading systems can significantly enhance building energy performance by regulating solar heat gain in cooling-dominated climates. However, a systematic strategy is required to evaluate the energy-saving potential of such systems during the design phase. This study investigates the impact of shading fraction (SF) on space cooling load through simulation-based methods in two major tropical climate zones of Asia. Two Köppen climate types are examined: humid subtropical (Cwa), represented by Hong Kong (China) and New Delhi (India); and tropical wet and dry (Aw), represented by Haikou (China) and Chennai (India). The tools employed include Revit for geometry modeling, Dynamo for shaded area calculation, and E-Quest for energy simulation. A custom Dynamo script was developed to calculate the hourly shaded area of horizontal and vertical fins by varying fin depth. These were categorized into five SF levels (45–95%) at 10% intervals for four orientations and four representative seasonal days. Hourly cooling energy demand for each SF case was compared to a base model without shading. Results show cooling load savings ranging from 6% to 14% across locations: Chennai (9–14%), New Delhi (7–13%), Hong Kong (6–13%), and Haikou (8–14%). Despite identical climate classifications, Indian cities showed higher savings due to higher mean monthly temperatures. These findings offer valuable guidance for climate-responsive shading design in highly glazed tropical buildings.