Analysis of the thermal behaviour of a low cost, single-family, more sustainable house in Porto Alegre, Brazil

Efforts have been made in Brazil to improve the thermal performance of low-cost buildings. Since 1997 studies on low-cost housing have been developed by Núcleo Orientado para a Inovação da Edificação, the construction sector of the Engineering College of the Rio Grande do Sul University, Brazil. In 2000 a prototype of a low-cost house was built on the university campus. This prototype has undergone several evaluations in an attempt to assess its thermal and environmental performance, like: energy consumption, rainwater harvesting, use of sustainably managed wood for window frames and doors, besides a detailed accounting of overall costs. The thermal performance of the house was monitored, by recording outdoor and indoor air temperatures and relative humidity, over the period of whole year. A brief appraisal of such results, as well as the annual heating and cooling degree-hours are presented. Daily swings in outdoor are a common climatic event in Porto Alegre and the building response to daily temperature swings, greater than 10 K, and hot and cold spells are presented. The results show that the thermal performance of the prototype is fairly satisfactory, considering the limitations of a low-cost house, when artificial heating and cooling is not affordable.