EXPERIMENTAL STUDY AND ENERGY BALANCE CALCULATION OF VENTILATED CERAMIC TILE ROOF IN MEDITERRANEAN CLIMATE

The impact of natural ventilation of a roof cavity on improvement of the thermal environment and reduction of cooling load of a residential building is discussed. The roof is one of the main elements of the building's opaque casing, where the choice of materials and the implementation of appropriate passive technologies determine the thermal performance of a building. An experimental study was conducted to observe the effect of cavity ventilation on the heat and mass transfer through ceramic tile roofs with vented eaves and sub-tiles. This paper refers an approach for building roofs with vented eaves, with a study of their thermal performance through a long-term experimental evaluation of the heat transfer in the different layers/ roof elements and the airflow along the air-gap cavity. To this end, a test cell was designed and built. It was tested outdoors under variable weather conditions, and monitored continuously. Various tests and energy balances were carried out in order to estimate and compare the heat flux through the various layers of the roof, thus characterizing this technology, its energy efficiency and its relevance in the management of energy demand in buildings. Results showed that the air velocity in the air-gap correlates with the intensity of the solar radiation, increasing with it, and there is a reduction in heat transfer by conduction when the heat transfer by natural ventilation increases.