Design Strategies for Optimizing Natural Ventilation in theMediterranean Area: Case Studies Analysis

According to the criteria of sustainable design, the study aims to develop an approach to the architectural design from the environment, considering it as a basic element of the design experience itself. In this context, the climate plays a fundamental role. Fielding and updating the bio-climatic design principles already formulated in the last century, in this paper underlines the contribution of natural ventilation to save energy in the mediterranean area, with the development of design strategies for both housing and urban scale useful for its optimization. The study is developed and verified through case studies and experiments. This topic dealt with the use of new physical and technical computational tools that allow the implementation of evolutionary methodologies of principles already made known many years ago. Through the simulation design applied to urban and building scale, in the case studies in the area located in the north-east of Italy, has been identified, as a general purpose, a methodological approach to the design and, as a more specifically objective, have been found the best design solutions for the optimal exploitation of the natural ventilation of the site. The mediterranean area, in fact, is characterized by an alternating hot and cold climate during the year and consequently is relevant the energy expenditure for achieving summer comfort. During the simulation in the case studies, given the overall expenditure for heating and cooling of a living unit in a year, has been found that the contribution of the natural ventilation of the global energy saving of the building is approximately 10%, and in summer the only reference to the contribution of natural ventilation to save energy up to about 60%. Furthermore, in relation to the topic of natural ventilation in the mediterranean area, becomes apparent that in addition to building scale it is necessary to consider also the urban scale, looking for design solutions that allow clusters of buildings to optimize the flow of wind to help the natural ventilation indoors. The design has been conducted using different computer programs specifically adapted, and has led to quantify, verify and assess the effects of the strategies adopted concerning the bioclimatic architecture. These strategies in relation to energy saving, differ conceptually from those identified and adopted in the countries of northern Europe in recent years, such as the “Passive House”, where an accurate and complete isolation from indoors to outdoor is provided . The study shows that for the specificity of the climate in the mediterranean area it is better to direct the research on design strategies in order to provide an interaction between indoor and outdoor through the non-negligible contribution of natural ventilation.