Experimental benchmark of the modelling of a rainscreen ventilated fa\ue7ade

The aim of this study is to present an experimental work carried out of a test building with a rainscreen wall that is a combination of external panel and ventilated fa\ue7ade, tested under real weather conditions. Field measurements were performed in winter period (from January 01th to March 31th 2010). In this work the modelling of the test building using a dynamic thermal simulation program (ESP-r) is presented and the main results are discussed. It is shown in the work how the proposed model can be used in order to make a parametric analysis of the thermal performances of the rainscreen fa\ue7ade and obtain important data about the sensitivity of the thermal behaviour of this envelope component on its main geometrical, material and fluid-dynamic constraints. The test devise is a building tower located in Italy, San Mauro Pascoli - Forli` Cesena (latitude 44.11N, longitude 12.43E). It was completed in November of 2009 with the purpose of detailed investigations of the external rainscreen wall energy performance. The test building is exposed to real weather conditions, but only the South and West sides have been equipped with a series of measurement units. The building has a squared base of internal dimension 2.89 m. There are three floors for a total internal height of 7.75 m, the door is on the North side and there are not windows. All external walls are three-layered with the middle layer composed of 24 cm air cavity ventilated and external side consisting of porcelain stoneware tile systems with open joints. At the top and at the bottom of this tower are located grills of ventilation. The roof consists in a sandwich panel and is not ventilated. The thermal analysis of this envelope component evidenced that the ventilated facade is able to reverse the direction of the heat flux through the envelope in regions characterized by large solar irradiation during the winter and moderate wind velocity, when the indoor-outdoor air temperature difference is small, thereby reducing the energy consumption required for indoor heating. Results of the model are compared with a series of experimental data obtained during the winter. The experimental data are used to select the best model to adopt for the numerical simulation of this kind of component in order to obtain detailed information on the thermal behaviour of the rainscreen ventilated fa\ue7ade by using Building energy Simulation tools like ESP-r