Thermal behavior of a ventilated wall: experimental data and CFD model validation.

Ventilated walls are an interesting technology to protect buildings from moisture and weathering. In this paper a ventilated wall made of traditional materials was analysed and improved by using CFD simulations; in particular a CFD model was implemented and validated by means of an experimental campaign. A test masonry wall was built at the Laboratory of Department of Engineering - University of Perugia; the two test chambers were respectively heated and cooled and the surveys were carried out until the stationary conditions were reached. The experimental campaign was carried out for about one month; the thermal behaviour of the masonry wall was monitored (temperature, air velocity, and heat flux) with and without ventilated air gap. Then, a CFD model was implemented and validated considering all the data monitored during an experimental campaign. In order to reproduce the monitored thermal behaviour of the masonry wall, the CFD model was implemented by applying different turbulent and heat exchange models; besides, a sensitivity analysis of mesh size was carried out, in order to evaluate the best configuration which allowed to correctly simulate the thermal behaviour of the wall. In this preliminary study, the CFD model was implemented and validated considering the stationary conditions and it represented the starting point for the development of the ventilated wall in unsteady state conditions.