Optimization of Building Envelope to Reduce Air Conditioning

Background/Objectives: Air conditioning in tropical buildings constitutes a major component towards the total energy consumption. General guidelines for reducing the incident solar radiation on the building envelope are available in literature. However information on the reduction in energy requirement is not readily available. Methods/Statistical Analysis: Reduction in energy requirement by varying the building planform, orientation and construction materials was studied. Findings: A building with a planform area close to the Golden Ratio and with the broader side facing North, resulted in the least amount of solar radiation on the surface of the building envelope. Further the white coloured buildings made of rammed walls and roof material with longer phase lag decrease the heat transfer into the buildings. Conclusion: The building orientation and planform are crucial in reducing the incident solar radiation on the building envelope surface. Use of white colour and materials like rammed earth for walls resulted in substantial reduction of the required cooling loads to maintain the indoor thermal comfort temperature.