Graphic tool for thermal and daylight performance analysis of façaades and definition of glazing type and horizontal shading devices in air-conditioned offices across three Brazilian climates

Abstract

This article presents a graphical tool for defining window parameters with a focus on thermal and daylight performance in three Brazilian climates: São Paulo, Belo Horizonte, and Manaus. The approach considers cooling load, Spatial Daylight Autonomy (sDA), and Annual Sunlight Exposure (ASE), while varying the window-to-wall ratio (WWR), solar heat gain coefficient (SHGC), vertical shading angle (VSA), and eight solar orientations, in a context without surrounding urban obstructions. Simulations were carried out using EnergyPlus and Radiance, through the Honeybee plugin for Grasshopper in Rhinoceros 3D. Results show how these parameters simultaneously influence thermal and daylight performance. It was found that façades with high WWRs can be viable when combined with solar control strategies, allowing the use of glazing with higher visible transmittance. Similar cooling loads to those of reduced WWRs (~30%) can be achieved while maintaining high levels of natural daylight—an outcome not always observed with small window areas. Finally, a design chart is proposed, correlating design parameters and performance indicators, providing a practical and didactic tool to support the design of façade openings.

Keywords
Windows; Thermal performance; Daylighting; Solar control