Numerical Assessment of Zebra-Stripes-Based Strategies in Buildings Energy Performance: A Case Study under Tropical Climate

Abstract

Urban growth has increased the risk of over-heating both in the microclimate and inside buildings, affecting thermal comfort and energy efficiency. That is why this research aims to evaluate the energy performance of buildings in terms of thermal comfort (operative temperature (OP) levels, satisfied hours of natural ventilation SHNV, thermal lag), and energy efficiency (roof heat gains and surface temperatures) in an urban area in Panama City, using superficial-heat-dissipation biomimetic strategies. Two case studies, a base case and a proposed case, were evaluated using the Designbuilder software through dynamic simulation. The proposed case is based on a combined biomimetic strategy; the reflective characteristics of the Saharan ant applied as a coating on the roofs through a segmented pattern such as the Zebra’s stripes (one section with coating, and another without). Results showed that the OP decreased from 8 to 10 °C for the entire urban zone throughout the year. A reduction of 3.13% corresponding to 8790 kWh per year was achieved for cooling energy consumption. A difference of 5 °C in external surface temperature was obtained, having a lower temperature in which the biomimetic strategy was applied. Besides, it was evidenced that a contrasted-reflectivity-stripes pitched roof performed better than a fully reflective roof. Thus, the functionality of Zebra stripes, together with the reflective characteristics of the Saharan ant, provide better performance for buildings’ thermal regulation and energy needs for cooling.

How bio-inspired solutions have influenced the built environment design in hot and humid climates

“…The fewest real-scale applications are in tropical climates, with only six found here, the Lavasa Hill Project (urban scale) (Zhong et al, 2022), Eastgate Centre (building scale) (Nkandu and Research, 2018), Sahara Forest Project Qatar (building scale) (Othmani et al, 2022), Office Building for D3 (building scale) (Eid et al, 2021), Infiltrates gardens (urban scale) (Indira et al, 2022), and The Esplanade Theatre in Singapore (building scale) (Srinivsan, 2020). In contrast, most studies are conducted from a dynamic simulation evaluation at both building and urban scales: the Old-town in Panama City (Austin et al, 2022) using Designbuilder for assessing the cooling needs reduction implications of implementing biomimetic-based roof coating (urban scale), and the heat island effect reduction using ENVImet (Araque et al, 2021). Moreover, the study of sustainability improvement at the city scale using biomimetic approaches (Quintero et al, 2021), where regenerative indicators are proposed, and the proposal of a biomimetic-based energy storage system evaluated under a tropical climate dynamic (Cedeño Quijada et al, 2022).…”