Parametric strategy on passive design affordances in cool-humid climate zones of North-East India

Abstract

Buildings often have fixed function spaces that are complimentary or incompatible with thermal comfort (18–28 °C). Synergetic relationships ameliorates energy shortage and affords comfort. Galvanized iron roof two-storey houses of North-East India were studied to develop a theory-and-strategy to optimize design process and energy conservation. Methods include affordance theory criticism, surveys, simulations, synergy analysis. Parametric strategy on passive design affordances examines human comfort and temperature on diurnal time scales: Daytime (08–17 h), Evening (17–22 h), Night (22–08 h) in various seasons. Under flexible ventilation, living-dining space (S1) shows optimum temperature ranges: 20–28 °C in autumn (M1), 17–22 °C in winter (M2), and 20–31 °C in summer (M3) due to the complementary combination of passive design elements and can function as bedroom, living-room, kitchen, and social space in most seasons. In the attic-space flexible ventilation shows peak temperatures of 42 °C (autumn) and 48 °C (summer) due to low thermal mass but high thermal conductivity envelopes, and low air-changes rate (0.5 ACR) above 28 °C. Normal ventilations with 30 ACR in autumn, and a combination of 30 ACR (night) and 0.5 ACR (day) in summer reduced maximum temperature to ≤35 °C in autumn, and ≤41 °C in summer. Attic-space (S2) shows ≤29 °C in winter daytime and ≥20 °C in summer nights due to the envelope’s high heat emissivity (0.8) and function as day space in winter and summer bedroom. Shaded veranda (S3) shows low temperature (18–28 °C) in summer evening and afternoon and can function as shaded space for light work and enjoying fresh air. Passive design connotes responsiveness of spaces to the climate, and affordance theory’s complementarity lifestyle adds novelty, and it is critical to energy and space efficiency. Climate analysis affords perceptions of space and climate relationship. Parametric strategy straddles differences between space, climate, and functions to ameliorate energy needs and optimize design process.