Developing a weather responsive internal shading system for atrium spaces of a commercial building in tropical climates

• The effective solution should have a large voice between the glazed roof and shading screen.
• Shading was operable/retractable to balance the needs for natural light and thermal comfort.
• Decision making was based on quantitative assessment on both energy and capital savings.
• Dynamic and cost models were created so that various solutions were be assessed fairly accurately.
• Dynamic models ran both thermal and lighting simulations for various scenarios.

In response to the non-trivial problem of overheating in glass roofed buildings in low latitudes a study was undertaken to reduce discomfort and high energy consumption in a large atrium building in China. This paper reports on the development of a shading system designed for that building as a remedial solution to reduce temperatures while maintaining adequate levels of natural lighting in the atrium spaces of a large multifunctional commercial building. The effects of the shading system on both the physical indoor environment and its economic implications were analysed using implemented models. Calibrated with the data measured in the building during the hottest season, summer, the models were used to test both thermal and lighting performance of two shading arrangements: high and low level blinds in both open and covered modes on typical overcast days and clear days in summer and winter respectively. Also tested were two types of fabric used for the blinds.The performance of these tested cases was assessed for solar gain, cooling loads, internal surface temperatures, air temperatures and operative temperatures of both ground floor and surrounding walkways on various levels within the atrium, the major circulation areas. The results reveal that the high level shading, with blinds fixed close to the glazed roof are generally less effective in the provision of thermal and lighting conditions of the atrium, than the low level shading, where blinds are fixed 3–5 m below the glazed roof to form a ventilated void. The financial benefits of these remedial solutions were also assessed using standard economic analysis methods to provide recommendations on their costs and payback periods.