Evaluation of the thermal performance in external vertical enclosures constituted of metal panels.

Abstract

Brazil has a great climatic diversity, with different demands for the adequate thermal performance of buildings, where the variables that impact it have different influences depending on the location and the type of wrapping used. When a prior study of the thermal performance of a building is not done in the design phase, the unpleasant effects for the user appear after the building is ready, and bring with them problems such as internal temperatures that are too high in the summer or too low in the winter. Therefore, the objective of this study is to provide recommendations for the application of ACM (aluminum composite material) composite panels and thermoacoustic (sandwich) tiles for external enclosure in the single-family residential sector. A high standard two-story residence with approximately 162 m2 per floor is used as a model and through computer simulations, utilizing the Energyplus program and observing the requirements of the NBR 15.575 performance standard, the thermal performance is evaluated. The factorial experiment was applied encompassing thermal performance variables such as absorptance, natural ventilation and thermophysical properties of the “wrapping for three different climatic conditions: extreme winter climate, average climate and extreme summer climate. The results obtained show that the thermoacoustic roof tile keeps the internal temperature more stable independent of external oscillations, while the ACM panels follow the external oscillations, not meeting the expectations of thermal performance and needing passive treatments.