CFD assessment of the performance of lateral ventilation in Double Glazed Façades in Mediterranean climates: Fid-Bau Portal

CFD assessment of the performance of lateral ventilation in Double Glazed Façades in Mediterranean climates

Guardo, A. / Coussirat, M. / Valero, C. / Egusquiza, E. / Alavedra, P.

Highlights ► Lateral ventilation in double glazed façades was numerically modeled. ► Four different lateral ventilation schemes were modeled. ► Swirl flow enhances radiative heat removal in lateral ventilation. ► Lateral ventilation requires lower flow rates than vertical ventilation.

Abstract Implementation of Double Glazed Façades (DGF) in buildings has been an object of broad study and application in recent years, both in new and existing constructions. However, there is little experience in predicting the operating behavior of a DGF. Sometimes the results obtained are not satisfactory and an extra energetic cost is necessary to obtain suitable comfort conditions in the inner space of the building, especially in Mediterranean climates, where large solar gains are a constant condition along throughout the year, and such large semi-transparent areas can produce significant over-heating in buildings. Computational Fluid Dynamics (CFD) has proven to be a useful tool for modeling air flow and heat transfer in DGF including conduction, convection and radiation heat transfer phenomena. The aim of this work was to evaluate, by means of CFD, the influence of several lateralventilation systems including the variation of the flow inlet (e.g., uniform or swirl flow inlet) and analyzing different inlet flow configurations (e.g., uniform, inclined, upper or lowercrossed inlet flow). From these CFD simulations, a comparative efficiency study, in terms of reduction of solar load gains and energetic requirements, was performed comparing the obtained results for horizontal ventilation against vertical ventilation, which was previously studied by this research group. It was found that using horizontal ventilation schemes would reduce the required air volumetric flow rate within the DGF for obtaining similar reductions in solar load gain to those obtained with vertical ventilation, when the construction and operation parameters of the DGF are equal for both cases.