The Impact of surface texture and wind on convective heat transfer from building façades

Öztürel, Necil
In this study, the impact of the surface texture of finishing materials and wind conditions on heat loss from the building’s facade are investigated. Three sets of samples (Set A, B and C) are tested and observed under varying wind speeds and varying wind angles in a wind tunnel. Both Sets A and B are composed of seven samples each, all having different surface textures. Set A samples were prepared from gypsum plaster and Set B samples from cement plaster mix. Set C consists of five different samples of conventional building materials (porcelain coated clay tile, travertine, marble, andesite and acrylic resin based composite siding material) with proprietary surface textures. Findings of the experiments are used in calculations within the introduced mathematical model where Roughness Index (RI) values for the sample surface textures are integrated and a set of convective heat transfer coefficient (h) and time constant (τ) values are presented for each sample. Correlation of these h values with the wind speed is investigated. It is found that variation in surface texture results in substantial deviations in h for varying wind profiles. The effect of surface texture of abovementioned materials and wind on h and τ is presented in comparative reference tables that can be used in further calculations of building energy fluxes.
Citation Formats
N. Öztürel, “The Impact of surface texture and wind on convective heat transfer from building façades,” Ph.D. - Doctoral Program, Middle East Technical University, 2013.