Undulated Glass Self-shading

Optical Benefits of Facade Figuration

Overview

Authors

Photo of Nebojsa Jakica

Nebojsa Jakica

Assistant professor in Facade Design and Engineering

University of Southern Denmark (SDU)

nja@iti.sdu.dk

Photo of Mikkel K. Kragh

Mikkel K. Kragh

Professor, Head of Civil and Architectural Unit

University of Southern Denmark (SDU)

mkk@iti.sdu.dk


Keywords


Abstract

The research is structured around complex optical effects of undulated glass and coatings that exhibit high reflectivity, especially at higher incidence angles. This optical behavior allows great directional and intensity variation even with minimal curvatures. This is especially visible in undulated glass facades, where the ratio of reflection and transmission changes dramatically with every change of viewing angle, producing dynamic effects. Furthermore, caustic and dispersion light effects may additionally enrich the visual architectural language. However, high-frequency and high-amplitude curvatures also create optical distortion and lens effects, thus producing undesirable glare and potential overheating. Therefore, these undulated glass geometries require special consideration and analyses during the design phase to maximize their optical benefits and reduce unwanted side-effects.

The research explores self-shading potential and optical benefits of undulated glass geometries through modulating surface curvature. Sinusoidal functions are used to define coherent procedural glass surface curvature with variable amplitude values. Due to the high directional sensitivity, virtual prototyping of undulated geometries was performed with a high temporal and spatial resolution and assuming the most common vertical setting.

Optical benefits are presented through g-value and daylighting metrics for a set of undulated glass facade states, varying curvature amplitude, and directionality. The results indicate moderate self-shading potential and daylighting benefit of undulated glass facades. The research findings aimed to provide a valuable resource for articulating design and performance aspects of undulated glass facades, potentially reducing the need for additional shading and daylight-redirect elements.

Introduction

Undulated glass facades

Since the introduction of glass in architecture, there has been significant progress in technology that made possible glass performance and size improvements. Nowadays, technologies such as thin glass

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Methodology

The methodology of the paper is based on the computational framework that defines the undulated glass façade system through a set of parameters controlling surface curvature. A computational workflow is

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Results

The results of experiment 1 are shown in Figure 7. The table shows g-values for both extreme states, planar and fully curved, plus five interpolation states. In total there are

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Discussion and Future Work

Given the experiments’ results, it can be concluded that undulated shading have multiple optical benefits. Firstly, figurated geometry of the glass surface can reduce g-value by up to 10% under

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Rights and Permissions

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