O efeito do vidro refletivo no microclima urbano: fachadas de edifícios comerciais

Abstract

The accelerated urban growth rate is alarming. As urban centers develop, is it noticeable the decrease in green areas while the increase of paved surfaces and built up density. Environmental changes, and especially the predicted increase in global temperature, make the phenomenon of urban heat islands aggravate thermal stresses, with the most severe effects in urban areas, mainly affecting the user level. The building envelope (vertical sealing, openings and roof) plays a prominent role in terms of interference with the external environment. The use of reflective surfaces on the skin of the building can severely affect the surroundings, causing overheating, glare and even risks to the health of the pedestrian. Buildings with large glass façade have been consolidating themselves as an international style of commercial architecture adopted in several countries and consequently, the use of glass, mainly the reflective type, is growing in certain neighborhoods of Vitória/ES. Thus, the objective of this research was to analyze the effect of using reflective glass on facades of commercial buildings, in the urban microclimate of the city of Vitória/ES. The methodology adopted was divided into four stages: characterization of the object of study and the physical and climatic variables, microclimatic measurements, computer simulations and parameters for analysis of the results. Therefore, the study area was defined and the field measurement was carried out. Then, the scenarios were calibrated and simulated in the ENVI-met software, one existing model and the others hypothetical, these differing from each other in the amount of reflective glass on the facades and only one with the use of colorless glass. The results show that the factors compared between the hypothetical scenarios: air temperature, mean radiant temperature, Physiological Equivalent Temperature (PET) and Universal Termal Climate Index (UTCI) demonstrate an increasing trend in the scenarios with the use of reflective glass, at the hottest times of the day, but the differences were not significant, with values in a range below 1ºC. This indicates that there is an interference of reflective glass in the urban environment, but it is minimal for the pedestrian in the studied microclimate.