Sustainability and thermal comfort of bamboo building technologies in the hot humid tropics: Linking mitigation and adaptation
Examensarbete för masterexamen
Industrial ecology (MPTSE), MSc
Ayala Laverde, David
The challenge of doubling the global building stock by 2070 has spurred interest in new building materials and technologies due to the critical environmental burdens associated with this growth. Affordable bamboo building technologies, potentially available in emerging and developing economies where most of the floor area growth is expected, emerge as an alternative. There is growing evidence that bamboo buildings outperform traditional materials in terms of global warming potential impacts. However, climate change's impact on thermal stress and the need for climate-adapted buildings require consideration of thermal comfort and energy needs. Bamboo buildings’ lightweight nature prompts exploration into whether it can offer thermal comfort while eliminating or reducing cooling energy requirements in hot tropical climates. This thesis addresses the link between building technology, thermal comfort, energy demands, and overall environmental impacts in the context of bamboo structures and non-residential buildings. The aim of the study is to test whether bamboo buildings can substantially mitigate environmental impact, offer thermal comfort while minimizing cooling energy needs, and continue to mitigate impacts when energy requirements for comfort are also considered. A case study building in the Philippines implementing bamboo trusses and composite-bamboo shear walls for a 149 m2 weaving centre is compared with a cradle-to-gate Life Cycle Assessment (LCA) to an equivalent building of widespread concrete and steel technologies. Adaptive comfort models are applied to on-site measurements and interviews at the case-study building to assess its thermal comfort performance. Building upon the adaptive thermal comfort statistical inference and regional climate models from different global emission pathway scenarios, an energy cooling load calculation is forecasted. The calculated potential energy needs are finally used to extend the LCA to include possible energy requirements for the case study buildings. The study concludes that bamboo buildings in this context have a potential to mitigate 271.3 kgCO2eq/m2 of cradle-to-gate GWP(100a) impacts when replacing widespread conventional technologies. A building-specific adaptive comfort temperature of TC =28.0°C is calculated for the case study building. And an adaptive thermal comfort performance indicator is defined to evaluate that the case study building does not deliver sufficient thermal comfort during 27.8% of its operating hours in a 16-week assessment period. The study concludes that the possible climate-adaptation of the light-weight structure might not be sufficient to guarantee thermal comfort without air conditioning. Environmental impacts from cooling energy requirement forecasts, especially under increased global emission scenarios, are shown to drive the cradle-touse impacts of the bamboo buildings; accounting for 86% of the GWP(100a) impacts of the case study building. However, the overall performance of the bamboo buildings is shown to sustain a mitigation potential (7.7 kgCO2eq/m2yr GWP(100a) impacts for the case study building), even when energy requirements for comfort are accounted.
Bamboo, Technology Assessments, Life Cycle Assessment, Thermal Comfort, Adaptive Thermal Comfort, Climate Adaptation, Environmental Impact Mitigation, Environmental Sustainability