Iluminação natural no poço de luz: investigando a influência das variáveis arquitetônicas por meio da simulação computacional paramétrica

Abstract

The light well is an architectural resource used to promote daylighting from the core of the building. It is often designed according to an index that considers its size according to the height of the building without taking into account the influence of each of the architectural variables on the gains in daylighting. Thus, the main objective of this study is to identify and compare the influence of architectural variables on the natural lighting performance of a light well in a residential building. To this end, a base model of a light well in the city of São Paulo, Brazil, was parametrically simulated, varying, in alternative cases, its geometric size, the reflectance of its walls and the window opening of the rooms connected to it. To evaluate natural lighting, the metrics Illuminance, Annual Sunlight Exposure (ASE1000) and Spatial Daylight Autonomy (sDA300/50%) were used through the Climate Studio software. The study was conducted in four stages: i) investigation of the path of light through the walls of the well; ii) verification of the incidence of natural lighting in the internal environments of the base model; iii) investigation of how the variation in the architectural configurations of the well affects the lighting of the environments and iv) proposal of an optimized model simulated from the best configurations found in the study. As a result, it was found that this negatively affects the lighting in the internal environments, since those at the top remain excessively illuminated, while those at the bottom do not receive adequate natural light. It was also found that increasing reflectance is a solution that improves the distribution of natural lighting without increasing the levels of direct sunlight, while increasing the geometric dimension results in greater direct sunlight reaching the well, not exceeding the fourth floor. To minimize the risk of visual discomfort in the environments, the windows should have a smaller opening in the upper half and a larger one in the lower half of the light well. The optimized model considered the light well in two halves, one upper and one lower, allowing for smaller openings at the top and larger ones at the bottom. In addition, a high-reflectance surface was applied to the walls and a 7m upper opening. This model resulted in a better distribution of lighting through the shaft. It is expected that the methods and results of this work can contribute to the investigation of daylighting in buildings.