Parametric analysis applied to the thermal performance evaluation of low-cost houses : a case-study in Curitiba, Brazil

The construction of dwellings for people with low incomes in developing countries encompasses a broad range of issues starting from the choice of the building site, to the construction phase and finally to the evaluation of the building itself. For tropical climates, the thermal evaluation of low-cost dwellings should be primarily related to the optimization of internal comfort conditions. Usually low-cost housing projects are implemented throughout Brazil equally, with no concern to the climatic region where houses are to be built. In this way, the same building system is applied in cities with very distinct characteristics. To correct these distortions, projects such as the research project Normalizao em Conforto Ambiental (Standards Development for Comfort in the Built Environment) are being developed in Brazil, with the aim of: helping to develop standards which promote buildings that are adequate for the climate. The Technological Village of Curitiba, the first to be implemented in Brazil, consists of 100 houses that are being inhabited, and 20 houses in the Street of Technologies which are displayed for public visitation, built with different materials and building systems. The first step of the present research consisted of a thorough evaluation of the thermal performance of the Villages 18 different building systems. The houses were occupied during the monitoring of air temperature and relative humidity (with data-loggers of the kind HOBO), which were carried out in winter and in summer. Measured data was then compared to specific parameters based on the recommendations of the Brazilian Comfort Norm. The last step of the research was to perform a parametric analysis of wall and roof thermal transmittance and time-lag and, by doing so, subsidize the development of the referred Norm. In this analysis, an statistical evaluation and thermal simulations were performed in order to verify the influence of the mentioned parameters in the thermal performance of low-cost houses.