Thermal simulation of ambients with regard to ventilated attics.

The idea that intend temperatures can be reduced by ventilating the air-space between the ceiling and the roof (the attic) of a house, is widely acknowledged by Civil Engineers and Architects. This phenomenon was evaluated through three softwares (CASAMO-CLIM, COMFIE and SPIEL) which were designed for the analysis of the thermal performance of buildings, by comparing the results of all three. The prototype of a popular house in three different locations in the State of Rio de Janeiro (Brazil), at Ilha do Governador, Jacarépaguá and Teresopolis, was used for the evaluation of summer conditions. It is understood that thermal comfort in hot climates is related to the energy consumption required for the artificial climatization of ambients, thus a reduction of this consumption can be attained if building techniques, aimed at the proper adaptation of the building to the local climat, are used, i.e. the employing passive solutions to achieve thermal comfort in the built environment. The ventilation of attics for the three climatic situations studied resulted in a small reduction of the inside temperature. It was verified, during the research, that this reduction was about tenths of a degree centigrade, for the most extreme climatic condition, at Governador. However, the utilisation of ventilated attics can help promoting an expressive reduction in residential energy consumption, if used alongside the adoption of other solutions of Bioclimatic Architecture, thus contributing to energy conservation in this area.