Experimental and numerical analysis of a naturally ventilated double-skin façade

This paper investigates the efficiency of a naturally ventilated double-skin façade (DSF) built in a test cell focusing on the airflow and heat convection of the cavity formed by DSF. The study covers measurements of the test cell and their numerical simulation. DSFs have been widely researched worldwide, since they contribute to the thermal performance of the internal environment and to energy savings by eliminating mechanical conditioning systems. For data acquisition, type K surface thermocouples are installed on the wall faces of the test cell and the additional façade, that is, on the inner and outer face of the wall of the test cell and the inner face of the external one. Furthermore, hot wire anemometers are positioned so as to obtain the air velocity in the lower and upper openings of the cavity, which has an air layer thickness of 0.1 m. The results show that the DSF presence contributes to a decrease of the temperature inside the environment because it inhibits the direct solar radiation. Measurement of the faces shows that at 4:00 p.m. the temperature reaches their maximum values. These values are equal to 25.6°C on the inner face of the façade and 23.6°C on the inner face of the test cell, while the outdoor temperature presents values equal to 23.1°C at this time.