Properties and applications of double-skin building facades

Abstract

A new era of commercial buildings is emerging in Europe, driven by innovative designs in Germany, Britain and the Netherlands. Engineers and Architects are collaborating to design a new typology of buildings that are energy efficient, environmentally friendly, and architecturally sleek. The common elements are double-skin facades (DSF's) that employ sun shading and air movement between inner and outer glass membranes. The doubleskin or "airflow" facade is tied to mechanical systems either physically with ducts or by significantly affecting the performance of those systems by reducing building loads. As compared to conventional facade systems, DSF's are credited with providing a 30% reduction in energy consumption, providing for natural ventilation even in skyscrapers, and providing valuable noise reduction. They also create a visually transparent architecture that is impossible with conventional curtain wall facades with similar properties. However, most building owners, architects and engineers do not have the language or analytical tools to analyze the appropriateness of this technology to buildings of varying occupancies and configurations and in various climates. Double-skin facades are defined and a typological system is proposed as a quick reference tool that will aid in understanding and communicating about the family of solutions that lie within a family of technologies that fit the definition of DSF's. A series of case studies examines a range of DSF typologies and analyzes their goals, structure, and relative success. An analytical model is developed and described to provide a flexible tool for evaluating energy impacts of a wide range of double-skin facade designs. A parametric analysis suggests how this model may be used as a design tool by emphasizing key properties of DSF systems. The analysis and model is applied to the potential technology transfer to Tokyo, Japan.