Modelling natural ventilation in double skin facade

The assessment of the energy performance of buildings with Double Skin Facades (DSF) requires proper dynamic simulation tools, based on models capable of predicting heat and mass transfer in the DSF under variable boundary conditions, at the price of a reasonable computational effort. Many DSF simplified models have been developed and implemented in building simulation tools, but the validation of these tools is still an open issue, especially for the prediction of the mass flow rate in naturally ventilated DSF. The CFD modelling activity presented in this work aims at investigating the reliability of the assumptions and hypotheses employed in the simplified model, which was specifically developed for the dynamic simulation of heat transfer in buildings. Both the CFD and simplified models have been tested and evaluated on an experimental case study, using the database provided by a research program developed under IEA ECBCS Annex 43/SHC Task 34, reporting the results of a measurement campaign conducted on an a transparent naturally ventilated DSF tested in Denmark, in an experimental facility called "the Cube".