Developing climate-responsive passive strategies for residential envelopes in the warm humid climate of South India

Abstract

PurposeEnergy codes for residential buildings in India prescribe design guidelines for each climate zone. However, these guidelines are broad and similar for different cities under the same zone overlooking climatic variations due to altitude, location and other geographical factors.Design/methodology/approachTo develop strategies addressing the city-specific requirements, a stepwise simulation approach was used. Integrated Environmental Solutions–Virtual Environment (IES-VE) was used to create a prototype of a singly detached residence. The applicability of strategies is studied during the day and night times. Optimum orientation, the thickness of insulation, Window–Wall Ratio, the impact of cross-ventilation and shading depth are determined for two cities – Tiruchirappalli and Coimbatore under the warm-humid climate zone of India.FindingsResults indicate that optimum insulation thickness and WWR vary between both cities during daytime and night time. In Tiruchirappalli, roof and wall insulation using polyurethane board (100 mm) and foam concrete (25 mm) offers a maximum reduction of 2.2°C indoors. Foam concrete (25 mm) insulation for roof and expanded polystyrene (25 mm) for walls reduce a maximum of 2.6°C during daytime in Coimbatore. Further, night ventilation with 20% WWR allows an average decrease of 0.5–0.6°C in triply exposed spaces facing the South. The use of a 2'0" depth shading device shows a maximum reduction of 0.1–0.3°C.Originality/valueThe contribution of this work lies in developing city-specific inputs presenting the advantage of easy replicability for other cities in the Indian context.