Otimização multiobjetivo do projeto de edificações residenciais para obtenção de baixo consumo energético na Região Sul do Brasil

Abstract

Throughout history, people have built their buildings looking for comfort and safety in an intuitive process of adapting to local conditions and climate. In view of the recent depletion scenario of conventional energy resources, society has sought to reconcile the use of renewable sources (sun and wind) for the thermal buildings conditioning, and thus achieve a consequent reduction in energy consumption. The design of low-energy buildings has been more intensified in countries with a predominantly cold climate, where the buildings are characterized by their adopted passive solar heating concept, with a high level of thermal insulation. But, currently due to climate change and urban heat islands, these buildings have moved away from a proposal for adaptability to the climate. Overheating and low indoor air quality have been reported in the literature, leading to the questioning of the super-isolated model as to the desired performance. In Brazil, research on low-energy residential buildings is recent and the application through the regulations in force is voluntary. Although the process is initial, an increasing consumption of electricity is being evidenced due the population growth and the contemporary style of energy use and conditioning of the environments. This shows the responsibility of the architects to adopt bioclimatic strategies in the architectural early design stage in order to reduce the future building energy consumption. Thus, decisions such as defining a more favorable orientation for the solar radiation gain, reach greater complexity when considering an interaction of several variables in view of a maximization or minimization of objectives that may be antagonistic, mainly in temperate climates. The resolution of complex problems is part of the studies of Operational Research, an interdisciplinary branch that makes use of mathematics to aid decision making with the use of optimization techniques. Due to advances in computer science, recent research in the field of construction has adopted a multi-objective optimization process with the use of evolutionary (genetic) algorithms that offer the opportunity to combine and adaptively improve solutions to certain problems. These tools have proven to be useful for application in the building performance field studies and, mainly, in studies dedicated to low-energy buildings. The main objective of the thesis is to contribute to the development of low-energy buildings in a temperate climate, showing the need of adequate decisions in the early design phase of the architectural design. It was intended to achieve adequate conditions of hygrothermal comfort and indoor air quality, under conditions of lower energy consumption and low associated investment, through a multi-objective analysis method for the optimization of building envelope, with the priority application of passive strategies iresponsive to the climate of the Brazilian Southern Region. The research emphasizes the diversity of climatic conditions found for the studied area, and analyses bioclimatic strategies levels to the most suitable to be obtained buildings with low-energy performances and presenting lower additional cost.