Will multi-facade systems reduce cooling energy in fully glazed buildings? A scoping study of UAE buildings

The objective of this work is to assess the impact of climate interactive facade systems (CRFS) on cooling energy in fully glazed buildings. This work integrates building energy simulation and computational fluid dynamics to establish boundary conditions and to develop geometrical models based on a new constructed multi-storey building. It performs 3D steady RANS CFD simulations, covering the CRFS, outdoor conditions and indoor environment. The result shows that the application of CRFS reduces solar gain into internal spaces, but increases the temperature within the system cavity. From a cooling energy standpoint, this study demonstrates that the CRFS is a construction solution that provides substantial savings for multi-storey glazed buildings in the hot arid climate of the UAE. On a typical summer day, between 17% and 20% of the energy required to cool the interior spaces can be saved. This range varies from orientation to another and depending largely on the level of irradiance and angle of incidence. The parameters that impact the most on cooling load are floor level related to screen height, followed by glazing properties and cavity depth in descending order. The outcome of this work offers to the building industry, a reliable indicator of the energy impact of climate interactive facade systems.

► Impacts of multi-facade systems on cooling energy in fully glazed buildings.
► CFD covering system cavity, outdoor conditions and indoor environment.
► Behaviour of multi-facade systems is affected by site and design parameters.
► Convective heat rates depend on the level of irradiance and angle of incidence.
► Screen height, glazing type and cavity depth have varying effects on solar gain.