Author: Dr. Mahnaz Mahmoudi Zarandi
The construction industry significantly impacts energy conservation. The increasing use of renewable energy sources necessitates innovative architectural solutions. Modern facade designs, including double skin facades (DSF), are becoming popular due to their unique creativity and practicality. While not a new concept, DSFs are increasingly utilized in architecture for their benefits such as enhanced occupant comfort and efficient use of natural, renewable energy. Thermal analyses indicate that DSFs outperform double-glazed facades in energy efficiency by creating thermal buffer zones that can be designed with specific openings to provide passive heating or cooling. However, their complexity and climate adaptability require precise design. The impact of DSFs on various building parameters makes their design crucial for overall building performance. The classification of DSFs is essential for influencing design stages, determining other design and technical parameters that affect thermal performance. Identifying the primary objectives of DSF implementation can guide functional and design requirements.
The book aims to introduce DSFs, their functionality, and advantages, providing a foundation for their design and implementation to promote sustainable architecture.
Chapter Summaries:
Chapter 1: Generalities of Double Skin Facades This chapter discusses environmental sustainability and the architectural benefits of utilizing natural resources. The interaction between the building's exterior and nature is examined from various aspects, including aesthetics, energy savings, occupant health, psychological impacts, and financial considerations. The facade, as a boundary between the interior and exterior, plays a crucial role in enhancing visual appeal, adequate lighting, ventilation, and reducing surrounding noise pollution.
The chapter also addresses smart architecture and facades as a foundation for DSFs. With advancements in technology and bionics, building skins are envisioned as analogous to animal skins, responsive to their environment. Accordingly, building facades interact with external environment variables, user thermal comfort needs, and internal environment, incorporating terms like flexible skin, active skin, responsive skin, and high-performance advanced skin.
Chapter 2: History and Definitions of Double Skin Facades
This chapter analyzes and reviews various definitions of the DSF system provided by researchers such as Harrison and Boake, Aronson, Otto, Kampango, and Klesens and Dahr. The general consensus is that an active facade covers one or more floors and consists of multiple glass layers, which may or may not be air-insulated. The air cavity between the layers can be naturally or mechanically ventilated, and the ventilation strategy may change over time. Generally, systems and devices are integrated to improve indoor air quality using active or passive techniques, often managed semi-automatically by control systems.
Design Goals: The design goals of DSFs clarify the necessity of their design. These goals include:
Advantages and Disadvantages: The chapter also discusses the advantages and disadvantages of DSFs:
Chapter 3: Types and Classification of Double Skin Facades
DSFs are designed in various forms, and this chapter categorizes them into three groups based on different criteria:
These classifications help in understanding the different design approaches and the impact of each type on the building's performance, aiding architects and designers in making informed decisions during the design process.
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Chapter 4: Thermal and Cooling Performance of Double Skin Facades
Double Skin Facades (DSFs) as an architectural phenomenon enable natural ventilation, improving indoor air quality without the noise and safety limitations present in single-skin facades. The choice of DSF type significantly influences the temperature, airspeed, and quality of air entering buildings. A well-designed DSF can reduce energy consumption during usage and enhance occupant comfort. Due to significant solar radiation in warm seasons, the DSF cavity heats up considerably. The buoyancy effect causes warm air in the DSF cavity to rise, creating a natural ventilation effect by drawing air from the building floors.
Different airflow patterns and the configuration of openings in the inner and outer layers of the facade can vary. This chapter presents two open-airflow patterns and three closed-airflow patterns. Depending on the climate, weather conditions, wind speed, and pressure, different patterns can be designed. Understanding these patterns can be intriguing for architects designing DSFs.
Chapter 5: Components of Double Skin Facades
The performance of a DSF depends on several factors:
The buffer space or cavity between the two glass layers in a DSF significantly impacts its performance. Important considerations for designing the cavity depth include:
Each parameter of the cavity plays a significant role in the facade's performance, and the book addresses each in detail:
Chapter 6: Case Studies
This chapter presents case studies of DSFs designed in major industrial countries that are pioneers in DSF design. Examples from Germany, Finland, England, Sweden, Belgium, the United States, and Australia are provided. Each case study examines the building's location, project timeline, overall facade structure, buffer space, shading type, and airflow pattern.
