Design and analysis of a window-integrated passive system (WIPS) with the use of solar heat gains

Abstract

As one of the passive building design strategies to decrease ventilation energy consumption, several window-integrated passive systems (WIPS) have been developed and implemented into buildings. This study proposed a new WIPS inspired by a double skin façade (DSF) design that provides pre-heating and ventilation by utilizing solar heat gains collected in the air cavities. The performance of the proposed WIPS was analyzed and developed based on different design parameters such as material, width, height, shape, depth, and opening area, for the wintertime in Seoul, Korea. Furthermore, the computational fluid dynamics model, Fluent 2021 R2 with the RNG k-epsilon turbulence model, was used for the simulation. To focus on the buoyancy effect occurring in the air cavities, the influence of wind was excluded from the CFD modelling and analysis. Therefore, 0 Pa pressure differences between the inlet and outlet of the room were applied. The results showed that the buoyancy effect increased in the WIPS with a wider and higher inflow cavity than a case with narrower and shorter cavity, also utilizing glass material for the cavity surfaces exposed to the outside resulted in absorbing more solar radiation and more buoyancy effect. Moreover, the converged shape cavity increased the volume flow rate of the cavity due to the increased air velocity from the Venturi effect. Overall, all design parameters can impact the performance of WIPS either by hindering or assisting the airflow of the WIPS.