Abstract

A Double Skin Façade (DSF) with photovoltaic panels and automated roller shading devices aims at the reduction of the energy consumption of the building and at the on-site generation of electricity while allowing for the possibility of admitting ventilation air from outside without the direct noise and wind-induced direct inflow from open windows.
A detailed transient finite difference model has been developed aiming at analyzing the thermal and electrical performance of an innovative DSF integrating photovoltaics and roller blinds (DSF-P). The model takes into account the effects of wind and the daylight provisions to the adjacent zone of the DSF-P. The energy balance of the system is described by a thermal network and a nodal flow network capable of assessing the wind effects on the cavity along with a daylighting model. In the modeling of the DSF-P the thermal behavior of an adjacent perimeter zone as well as the shading that the photovoltaics and the roller blind provide to the interior skin of the building are also simulated.
The model developed was used for the numerical investigation of various flow rates and shading configurations for a south facing three-storey double skin façade considering a typical year in Montreal (Canada). Different flow rates inside the cavity and shading configurations were considered and simulated. It was concluded that the optimal cavity width, in which the electricity consumption of the DSF-P system is minimized is between 0.2m and 0.6m (0.07 and 0.21 L/H); the electricity generated from the photovoltaics integrated on the exterior skin may cover the total electricity consumption of the adjacent zone; and for some cases an energy positive DSF-P can be generated.