LAUSR

Abstract Many high-rise buildings have intricate facade appurtenances such as balconies, mullions, or egg-crates shading elements. These facade systems interact with the external microclimate in a complex manner that affects the convective heat transfer coefficient (CHTC) significantly. In this study, CFD and heat transfer simulations are carried out for buildings with balconies, vertical shading element, egg-crates, and a smooth facade. Comparisons of local-CHTC distribution between buildings with and without the facade appurtenances for rooms on different floor heights and located at a corner or a center region of the building are performed. Two equation SST κ-ω turbulence modeling is used for momentum closure. The result of this study shows that the local and surface-averaged CHTC values at the surfaces of each building are dependent on building aerodynamics and forms of the facade appurtenances. For instance, for a 100 m tall building case study with rectangular floor plan, having an egg-crate shading with a depth of 1 m decreased the local-CHTC of a room around the corner-zone by 35%, 37%, and 38% on the 1st, 15th, and 30th floors, respectively compared to a room in building a smooth facade. Thus, necessitating detail local-CHTC variations and wind directionality effect assessments especially on glazed buildings characterized by weak thermal performances.