Resiliência de habitação de interesse social unifamiliar em região de savanna frente às mudanças climáticas

Abstract

As scientific research shows a progressive increase in earth temperature, climate change is recognized as a key global challenge for the 21st century. Studying the consequences of this phenomenon has gained worldwide importance, including in the field of buildings. It starts from the problematic that comes from the housing models that, nowadays, are already constructed with inadequate thermal insulation, raising the question about what internal conditions will favor in these future heating scenarios. The main objective of this work is to analyze the effects of global warming on 21st century housing, incorporating the effects of global warming from the perspective of habitability and the resilience of buildings to climate change. The emissions scenario A2 of the Fourth Report (AR4) of the Intergovernmental Panel on Climate Change (IPCC) was considered. The methodological procedures consist of five stages: preparation of the climate files for Future Scenarios (time-slices 2020, 2050 and 2080) from the archive without influence of global warming (1961-1990), called the Base Scenario; quantification of the impacts of global warming on the project strategies, determining the bioclimatic potential in the times-slices for the Base and Futures Scenario; definition of a dwelling for study object (Tbase) and its setting in the best levels of the Brazilian norms and regulations of thermoenergetic performance; elaboration of intervention proposals in the object of study, defining six typologies (T1 to T5) through the adoption of passive design strategies in the envelope, namely: increase of thermal resistance and thermal capacity; computational simulation of the typologies for the purposes of thermal performance evaluation, energy efficiency classification, analysis of thermal comfort conditions and estimation of energy consumption for cooling, all considering the main facade facing north. Under the effects of global warming, the annual average temperature and relative humidity of the external air in the Base Scenario varied from 26.73°C to 32.48°C (+5.75°C%) and 69.08% to 53.67% (-22%), up to the time-slice of 2080, respectively, compromising the habitability of the Tbase typology: the hours of heat discomfort increased from 3,410 hours in the Base Scenario to 7,189 hours in the 2080 time-slice. The typologies T2, T3 and T4 presented similar behavior, and the T5 presented the best thermal behavior: 1,148 hours in the Base Scenario and 6,841 hours in 2080. Tbase presented the "Lower to Minimum" thermal performance rating, considering the current methodology in the Base Scenario and the 2020 time-slice, ranking as Superior in the 2050 and 2080 scenarios, as well as the other typologies in the four scenarios analyzed. The Tbase and T5 typologies present energy efficiency ratings "C" and "A" in the Base Scenario, respectively, and both as "E" in the 2080 time-slice. It is concluded that considering the useful life of 50-year-old buildings, it is necessary to re-think the current constructive specifications, incorporating interventions to absorb the impacts of climate change, pointing out guidelines on how to build today, to provide better and more resilient climate habitability in future climate scenarios.