Design optimization of a solar system integrated double-skin fagade for a clustered housing unit

The study compares a conventional double fagade (DF), a building-integrated photovoltaic double fagade (BIPV DF), and building-integrated photovoltaic thermal double fagade (BIPVT DF), by considering the impact of the depth of the cavity between the photovoltaic system and the fagade. The problematization aims at augmenting the function of an interstitial spaces between building envelope and programmed space both in terms of spatial expansion, but also in terms of energy production. The approach involves examining this space in terms of its spatial parameters and ability to accept an architecturally integrated solar system. To conduct the present analyses, three distinct systems were employed and applied to a sample thermal zone, where the cavity space shaped by the double fagade was considered as a veranda space. The energy systems were modelled utilizing the commercial software DesignBuilder, and various dynamic simulations were performed using the building energy simulation software EnergyPlus for a representative South-Eastern Mediterranean weather zone. A parametric analysis was conducted, which involved varying the cavity depths from 0.25 m to 1.50 m. Results show that the conventional DF system demonstrates lower heating demands than the other systems, whereas the opposites occur for the cooling needs. Furthermore, an increase in the cavity depth between the PV system and the fagade resulted in an increase in heating thermal loads and a decrease in cooling loads. The primary energy minimization approach provided interesting results, including the optimal depth cavity of the veranda (0.97 m).