Analytical studies of the Sirocco room of Villa Naselli-Ambleri: A XVI century passive cooling structure in Palermo (Sicily)

This work focuses on a passive cooling architecture particularly popular from the Renaissance in Palermo area, as building sumptuous suburban villas became a real hobby for the Sicilian aristocracy. A Sirocco room is an artificial subterranean construction, built close to a water spring in order to reproduce the pleasant conditions of freshness that could be experienced in a natural cavern. In these places, nobles used to spend their time with friends to escape from the hot summer. The room of Villa Naselli-Ambleri is nowadays the best preserved in Palermo thanks to its owners' conservation care and it is unique for its cooling operating principle. The above-mentioned considerations make this structure worth of deeper analysis regarding its architectural configuration along with some climatic studies. Following a well-established procedure intended for an intimate knowledge of historical architecture, the construction has been investigated from various points of view. A preliminary analysis of ancient documents (manuscripts, notary deeds, pictures) was performed to outline the historical evolution, the materials and constructive techniques used and the possible modifications it had undergone. Then, an architectural survey was performed in order to evaluate the geometrical/dimensional features. The collected data were compared with the historical quotes previously acquired. Furthermore, some thermo-hygrometric measurements were performed with the purpose of studying the unique cooling operating principle that is caused by the room peculiar architectural configuration and by the interaction water-air-limestone, recalling the antique Persian systems of passive cooling. Such a scheme was partially modified during the beginning of last century reducing de facto the cooling effect; a potential restoration project, as hoped by the owners, the Counts Naselli Dukes of Gela of the Princes of Aragona, will deal - as a central theme - with the reconfiguration and re-functionalization of the structure. The knowledge of such a construction and operating principles is also particularly important to re-discover the forgotten "places of delight" that are a fundamental element in Palermo history and culture, a central part of its population identity. Furthermore, preservation and reuse of surviving rooms represent a useful way to understand a simple passive cooling system whose principles could be reproduced in a contemporary way in modern buildings intended for a valid and functional energetic control.