Natural Ventilation with Dynamic Façades

In the light of global environmental problems, it is vital for buildings to conserve energy and make use of natural energies. Natural ventilation is one important method for achieving this. In houses, natural ventilation is a very attractive way to control the indoor environment. Compared to this, mid- to high-rise buildings include many closed spaces where windows cannot be opened and internal heat is trapped inside, which increases the cooling load. Based on this situation, consciousness of environmentally friendly buildings and utilization of natural energy becomes high. Introducing fresh outside air directly into the indoors can create a more comfortable environment for building occupants, in addition to realizing energy savings. Natural ventilation is commonly implemented in buildings such as homes, but its application in mid- to high-rise buildings has been hampered by many issues such as ensuring building performance and determining control methods. Therefore, design techniques for natural ventilation are strongly required. Design techniques for natural ventilation have been developed and applied to many buildings in Japan. This paper describes the outline of the design technique developed by the authors and introduces some examples of natural ventilation with dynamic façades in non-residential buildings in Japan.