Airflow and Heat Transfer in Sustainable Building Components: Double-Skin Facades

Double skin facades (DSFs) are building envelopes comprised of two glass facades, a ventilated air cavity and shading devices placed within the cavity. In this paper airflow and heat transfer simulation was conducted for a DSF system equipped with a venetian blind using computational fluid dynamics (CFD) with RNG turbulence model. Simulation was done for a three-level combination of slat tilt angle and blind position. The heat transfer coefficient was directly obtained from CFD simulation. The CFD prediction was validated using experimental data collected for a mechanically ventilated DSF (1.6 m wide and 2.5 m high and 0.15 m wide cavity) equipped with venetian blinds. The present study indicates that the presence of venetian blinds influences the surface heat transfer coefficients (SHTCs), the temperature and the air distribution in the DSF system. Specifically, for the cases considered, the position of the blinds is more important than the slat angles.