Desempenho luminoso de escritórios com grandes aberturas no clima tropical úmido

Abstract

Highly glazed facades have spread worldwide in office buildings to combine aesthetics, transparency, and external view. The windows bring benefits through daylight use and views outside but can cause discomfort due to glare from direct sunlight on the plane or the sky brightness in the field of view. Occupants react by closing internal blinds to mitigate the discomfort, compromising the functions of the window. The daylight performance can be preserved by avoiding or mitigating discomfort glare, considering the interdependence between façade characteristics and room occupancy. This research determines design configurations for office environments with high-glazed facades capable of providing daylight use and outside views in a humid tropical climate by mitigating glare. Different combinations of facade systems (orientation, window-to-wall ratio, sky view factor, and visible transmittance), occupant position (distance from the window and field of view), and occupant behavior (frequency of interaction and glare perception) are investigated in the climatic context of Natal/RN. The method consists of parametric simulations in Climate Studio/Grasshopper and proposes a multicriteria approach to relate Spatial Daylight Autonomy (sDA), view out, and Daylight Glare Probability (DGP). Results show that glare is the main limiting factor for the opening use and that the user's field of view and the distance from the window are the most sensitive parameters. The primary strategy for harnessing daylight is to determine the façade design if there is a defined internal occupancy and to plan occupancy according to the façade's performance. The perimeter zone should be avoided because it usually tends to compromise the window. The daylight use can vary by up to 95% of the area when considering the occupant, demonstrating that the design of highly glazed façades must recognize room occupancy in terms of the user's position and interaction.