33 © Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin · Bauphysik 30 (2008), Heft 1 The aim of this project was to analyze the thermal performance of passive low-cost housing in half-humid tropical climate. The houses are located in Cuiabá-MT (15.5° southern latitude), one of the hottest cities in Brazil. The data about the typology of the houses were obtained from three representative construction systems; wood, masonry, and prefabricated. The measurements had been carried out through a year, during 20 consecutive days of each season and were evaluated by three distinct methodologies: (1) analyses of previous recommendations of the construction where the envelope materials were compared with the Brazilian standard NBR 15220-3/ 2005, (2) frequency, through dry bulb temperature with values of 18 °C and 29 °C, and (3) performance, by analysis of comfort levels and bioclimatic strategies processed by Analysis Bio 2.1.2 program in accordance to the adapted Bioclimatic Chart of Givoni for deve- loping countries. Thermisches Verhalten dreier kostengünstiger Wohnhaustypen im tropischen Klima Brasiliens. Ziel des Projektes war, das ther- mische Verhalten kostengünstiger Passivwohnhäuser im halb- feuchten tropischen Klima zu untersuchen. Die Häuser befinden sich in Cuiabá-MT (15.5° südlicher Breite), eine der heißesten Städte Brasiliens. Die Daten über die Typologie der Häuser wurden von drei repräsentativen Bauweisen gewonnen: Holz, Mauerwerk und Massivbauweise. Die Messungen wurden innerhalb eines Jahres während jeweils 20 aufeinanderfolgenden Tagen in den vier Jahreszeiten durchgeführt und nach drei Kriterien ausgewertet: (1) Untersuchung der Konstruktionsempfehlungen und Vergleich der Außenwandkonstruktion mit der brasilianischen Norm NBR 15220-3/2005, (2) Häufigkeitsverteilung der Temperaturwerte 18 °C und 29 °C, sowie (3) thermisches Verhalten mit Untersuchung der Behaglichkeit und eines bioklimatischen Konzepts mit Hilfe der Software Analysis Bio 2.1.2 in Übereinstimmung mit dem darin ver- wendeten Bioklimatischen Diagramm für Entwicklungsländer nach Givoni. 1 Introduction In Brazil, low-cost housings still possess order, space, ratio, and constructive systems practically fixed. In accordance with Krüger and Lamberts [1], the low-cost housings destined for the low income population still have a fixed form in all Brazil and do not take into consideration the different cli- mates existing in the country. In the State of Mato Grosso, the low construction stan- dards for the region thanks to the national standardization used for projects of low-cost dwellings harms the thermal performance of the houses. This inhibits even more the se- cular habits of Cuiabá population by forcing them to rest on the sidewalk in front of houses or under the shade of a traditional “Mangueira” tree. This phenomenon is generally considered as a socio-cultural behavior more is perhaps a mechanism of thermal comfort. In recent years researchers from south and southeast regions of Brazil are developing a consistent form of research on the thermal performance in habitations in thesouthern region, specifically for the subtropical climate. The research contributes enormously to the develop- ment of new project methodologies, and regularization of the NBR 15220-3 [6] and project SWERA (Solar and Wind Energy Resource Assessment), project of the United Na- tions Environment Programme (UNEP). However, these researches are still insufficient for the climate of the state of Mato Grosso, specifically in one of the hottest cities in the country Cuiabá, and devoid of thermal-projected buildings. This study aims to evaluate and compare the thermal per- formance of the predominantly used constructive systems of this area. 2 Clima The climate of Cuiabá region (15.5° southern latitude) is in accordance with the climatic classification of Köppen [2], “Aw type”, tropical, humid, and typical of tropical savannas. It is characterized by presenting two well-defined periods: the dry period (October– April) and the humid period (November–March) during which 80 % of rains occur. Cuiabá has a small thermal amplitude, except in the phe- nomena of cold mass, the annual average temperature is 26.8 °C, the maximum average temperature is 42 °C, the minimum average temperature is 15 °C, the average rela- tive humidity is 78 %, and the average total insulation of 2,179 hours per year, INMET [3]. 3 The houses The object of this study is to analyze the construction sy- stems more separately, without external influences, that is, variables such as microclimates, pollution, heat island ef- fect, and ventilation interference because of high con- structions. Thus, the analyzed residences had been con- Thermal performance in three different low-cost dwellings for the tropical climate of Brazil Marlon Leão Erika F. T. Borges Leão Marta Cristina de Jesus Albuquerque Nogueira José de Souza Nogueira Fachthemen DOI: 10.1002/bapi.200810004