New Possibilities of Sun and Glare Protection with a Structured Switchable Glazing

Abstract

Glazing units used for architectural applications have an enormous potential for optimization. Currently, daylight management as well as solar and shading control can be provided only through a combination of various individual elements, such as glass panes, venetian blinds and additional glare protection elements. This combination of several separate elements not only leads to a higher consumption of resources, as well as higher production costs. It also entails additional maintenance costs. In order to overcome these shortcomings, the authors have developed a switchable glazing unit with adjustable light and energy transmission properties. This unit uses an anisotropic liquid. The functional component consists of a liquid crystal layer enclosed between two coated glass substrates, thus it is an integral part of the glazing unit. Due to the structure of the conductive layer, it is possible to subdivide the glazing unit into small areas (so-called pixels) that can be switched individually. The transparency of each pixel can be controlled independently. The glazing unit itself can be used as an effective daylight and shading control. This integral approach opens the door for new architectural applications. The authors currently focus their research on the development and tests for control strategies of the switching process itself. These control strategies are numerically validated and then tested at the ILEK façade test facility. The paper presents the first results of a performance analysis based on numerical simulations.

Keywords

• Switchable glazing
• adaptive glazing
• liquid crystals
• control strategies
• building simulation