PROCESSO ALGORÍTMICO NA ESTIMATIVA DE CONDICIONAMENTO PASSIVO COM USO DE PCM

Abstract

PCM - Phase Change Material - are materials with large latent heat storage capacity. The incorporation of PCMs into walls is capable of providing appropriate passive conditioning of buildings in certain regions. The objective of this article is to establish an algorithmic process to estimate the effectiveness of the use of PCMs in the passive conditioning strategy "Thermal Mass with Night Ventilation" in the Brazilian northeastern semi-arid region, allowing different comfort parameters and defining specific melting points for effective use of PCMs. The method is divided into three stages: 1. Data acquisition; 2. Data processing with algorithmic tool; 3. Data analysis. The source of the data used consists of 74 INMET weather data files; the data was processed through an algorithm built by the authors with the software Grasshopper and the plugin LadyBug, testing two up bounds for humid ratio (0.012 and 0.017 g steam /g dry air); the processed data were analyzed by descriptive statistics. The resulting statistical values show the climatic diversity of the analyzed region, revealing that a considerable part of the locations does not benefit from the passive strategy if lower up bounds for humid ratio are considered. The results for the ideal melting point values for PCMs correspond approximately to the temperature range of the comfort polygon established by ASHRAE (between 25.5 and 27.1 °C). As PCMs tend to stabilize temperatures around their melting points, the values presented are interesting for the maintenance of environmental thermal comfort following the established parameters and allow the maximum efficiency of these materials in any of the studied locations.