Perimeter-area ratios and thermal discomfort due to excess heat in rural mud architecture of jharkhand: A study through simulation and temperature measurements in composite climate

Abstract

Mud huts with clay-tiled or thatched roofs are an integral component of Jharkhand’s vernacular architecture. Available literature suggests that more compact a dwelling unit, lesser is the heat gained by radiation by that dwelling unit in composite type of climate. In this study, ten different dwelling units with different perimeter-area ratios, but similar in all other respects, are recreated digitally and simulated through Autodesk Ecotect (Version 2011) software to generate their total number of discomfort hours inside them due to excess heat. Thereafter the correlation of their perimeter to area ratios to the total number of discomfort hours due to excess heat inside each of them is worked out. The computer software simulation results are verified by actual temperature measurements taken in peak summer in each of the ten dwelling units chosen for study. A moderate degree of correlation (0.48) is found to exist between perimeter-area ratios and total number of discomfort hours due to excess heat. However, dwellings with very similar perimeter-area ratios are found to have widely varying total number of discomfort hours due to excess heat. This fact is further verified by taking temperature measurements in the hottest part of the year, which show that the temperatures recorded in those dwelling units which show more number of discomfort hours due to excess heat, also show corresponding higher temperatures as compared to those dwellings which show less number of discomfort hours due to excess heat. Also, the same circular dwelling with thatched roof as actually exists on site shows lower peak summertime measured temperature than the simulated peak summertime temperature of the same dwelling unit with clay-tiled roof, all other conditions about the two huts being the same, illustrating the better insulation properties of thatch.