The use of second building skins is becoming a trademark in modern architecture, opening for innovative solutions, such as three-dimensional (3D) systems. This paper explores the potential of these systems to provide adequate solar protection to glazed façades by means of an advanced optical characterization. Spectral transmittance and reflectance of fourteen samples, belonging to several technological families, are measured with a built-in spectrophotometer, suitable to accurately characterize complex semi-transparent systems. Solar and lighting properties are then calculated. The normal optical properties strongly depend on the openness factor, thus the geometry primarily affects the performance. A total of 11 samples exhibit normal solar transmittance in the 40–53% range; the value decreases to 20% for the plissé metal grid and increases to 70% on average for metal meshes. The angular transmittance depends on the system texture geometry and its self-shading capabilities. It was found that such systems underperform as static conventional shading systems; however, one of the metal meshes, the plissé grid and the plastic grid exhibit relevant angular selectivity, with transmittance decay at 60° in the 58–72% range compared to the normal incidence value. The results show that some of the selected 3D systems provide adequate solar protection. The developed dataset can be used for early-stage design analyses, as well as for energy performance model input and validation.
On the Optical Characterization of Architectural Three-Dimensional Skins and Their Solar Control Potential
Zinzi M.
2022-01-01
Abstract
The use of second building skins is becoming a trademark in modern architecture, opening for innovative solutions, such as three-dimensional (3D) systems. This paper explores the potential of these systems to provide adequate solar protection to glazed façades by means of an advanced optical characterization. Spectral transmittance and reflectance of fourteen samples, belonging to several technological families, are measured with a built-in spectrophotometer, suitable to accurately characterize complex semi-transparent systems. Solar and lighting properties are then calculated. The normal optical properties strongly depend on the openness factor, thus the geometry primarily affects the performance. A total of 11 samples exhibit normal solar transmittance in the 40–53% range; the value decreases to 20% for the plissé metal grid and increases to 70% on average for metal meshes. The angular transmittance depends on the system texture geometry and its self-shading capabilities. It was found that such systems underperform as static conventional shading systems; however, one of the metal meshes, the plissé grid and the plastic grid exhibit relevant angular selectivity, with transmittance decay at 60° in the 58–72% range compared to the normal incidence value. The results show that some of the selected 3D systems provide adequate solar protection. The developed dataset can be used for early-stage design analyses, as well as for energy performance model input and validation.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
