The sirocco chambers: passive cooling structures in the XVI century Palermo area

In the past centuries, the plain surrounding the city of Palermo saw the construction of tens of suburban manor houses, called villas, which were referred to as “places of delight” for the amenities they offered during the good season. These architectural machines were built by aristocrats to make living in the countryside more pleasant and to exhibit their families’ richness and power. Among the delights, the Sirocco rooms were very common in Palermo from the Renaissance, and especially beyond to the XVIII century. They were artificial subterranean structures, built close to a water spring in order to reproduce the pleasant conditions of freshness that could be experienced in a natural cavern. In such places, nobles used to spend their time with friends to escape from the hot summer. In this work, we will discuss this architectural system typical of the territory of Palermo with particular reference to the room of Villa Naselli Ambleri, one of the best preserved. An accurate relief was performed and many archives documents were studied in order to outline its evolution and constructive characteristics. Furthermore, some thermo-hygrometric measurements were taken to study its unique operating principle caused by its peculiar architectural configuration and the interaction water-air-limestone, taking its origin from antique Persian systems of passive cooling. The knowledge of such structures and operating principles is nowadays particularly important to re-discover such “forgotten places” that are a fundamental element in Palermo history and culture, an invisible line that bonds together different Mediterranean countries where a wise and expert exploitation of natural resources made, and still makes, liveable inhospitable environments. Preservation and re-usage of surviving rooms also 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.