Smart Glass Facade Systems and Their Technologies

Glass has a high U value and cause more energy loss compared to other building materials. To decrease the energy losses of glass, which is determined to generate 60% of the heat losses of buildings, has a great contribution to the energy saving of the building. Low-E coated glasses, known as static glasses, can provide higher energy performance than regular glasses. However, they are insufficient as they cannot adapt to changing climate features in order to provide energy performance and comfort level at the same time. Therefore, parallel to the developing technologies, glass façade systems and technologies have been developed in order to provide energy performance and comfort level at the same time, and took their place in architecture as "smart glasses". In this study, the working principles, technologies and application areas of the different types of smart glasses are examined. Advantages and disadvantages of 17 different smart glass façade technologies, 7 passive smart glasses and 10 active smart glasses, are presented in a comparative way. The biggest disadvantage of passive smart glass systems is that they do not allow human intervention in adverse situations. For this reason, their use in buildings is not preferred. However, the possibility of pulling U values of aerogel glasses and vacuum tube glasses from passive smart glass systems to very small values is an important invention in preventing energy losses. There is more development for electrically powered smart glass systems. User compatibility has enabled them to be more preferred in buildings. The most used types are electrochromic glasses. The fact that liquid crystal glasses and suspended particulate glasses, which are active smart glass systems, require continuous power to remain active, have made them less preferred in buildings in terms of energy saving.