One-and-a-half skin glass facade

Double skin facades are very popular and offer advantages over the "single skin" that can be synthesized in: greater efficiency in summer and winter, the ability to accommodate protected mobile shielding systems and maximize natural light and transparency. These advantages are countered by disadvantages that are essentially the result of increased space consumption and higher costs. In temperate climates, characterized by mild winters and hot summers, the cost of double skin is generally not compensated by the advantages it offers. A dynamic facade, using glass and curtains, was designed for a specific project on a small conference room, in an office building in Rome. Regarding the facade, the objectives of the project were to have the maximum possible transparency of the glazed volume and the possibility of integrating systems to partially shield or obscure the room. At the same time, allowing the air space to be used most of the year.Ambitions - the design of a one-and-a-half skin facade. During the summer months, the facade of the building receives only a few hours of direct radiation in the morning, then the adjacent buildings create shade. This condition made it possible to conceive a volume with a large glass surface, a solution that in a different condition, with greater irradiation, would have been difficult to achieve in Rome.The first skin is a glass facade, while the inner skin is made up of two roller blinds overlapping to form a 60 cm air space. The curtains are made of interwoven narrow mesh fibre sheets, the first is white fibreglass with a high reflecting power and diffusing light, the sec-ond is carbon fibre with a high darkening power. In winter, the curtains are used only to diffuse the light inside or decrease the level of lighting. In summer, the curtains are lowered and generate the air space. The vents, placed on the floor and at the top, open generating an upward flow of air that expels the accumulated heat. When the temperature in the air space increases, the flow of air from natural first becomes forced and then, to further increase the heat exchange, the air is cooled. A preliminary investigation on the facade behaviour in the passive asset has been conducted. Several configurations have been inves-tigated to evaluate temperature values in the room and in the gap, with or without natural ventilation and different type of curtains. Considering various combination with fixed external condition and no mechanical system. The project is in progress and since we have a real building, this case study will be furthermore investigated; a in-field monitoring survey, to measure the relevant environmental parameters, is being planned. A more in-depth analysis, with the energy simulation of the building and the estimate of energy savings, will be carried out in combination with the indoor environmental monitoring, as a second step of the research