Integrative Passive Design for Climate Change: A New Approach for Tropical House Design in the 21st Century

Abstract

This article presents a new approach to passive building design which takes intoaccount the impacts of climate change. The approach involves considering the relative performance of a range of low-energy, passive design alternatives under a projected future climate. A low-cost housing project in the hot-humid tropics of Thailand is used herein todemonstrate the application of this new design approach. Theoretical analysis is carried out and shows that if the potential changes in the ambient temperature, solar radiation and humidity driven by climate change are taken into account, a combination of a number of passive design techniques, including passive cooling, is likely to be required to achieve interior thermal comfort and energy efficiency in these houses. To eliminate the requirementfor air-conditioning, the houses should be laid out in a staggered fashion on the plot tomaximize airflows between the houses. Each house would also benefit from having its service areas (e.g. kitchen and bathroom) located on the west side to act as a thermal buffer for its main spaces (e.g. bedroom and living room). A combination of a double roof and shaded double façades would also be advisable to provide effective protection from strong solar radiation. The use of thermal mass in conjunction with passive evaporative cooling and natural ventilation would help further to provide the cooling needed in more extreme weather. The analysis shows that, with all the above techniques in place, up toa 95 per cent reduction in energy use for cooling could be achieved in the passive house, compared to the energy used in a typical air-conditioned house operating in the same conditions, while achieving a comparable level of comfort. A discussion on how to generalizethis new design approach to houses in different settings is provided.