Analysis of wind-driven flow and external convective heat transfer coefficients for the bestest model building

Building energy analysis are very sensitive to external convection heat transfer coefficients so that some researchers have made sensitivity calculations and proved that depending on the choice of convective heat transfer coefficient values, energy demands estimation values can vary from 20 to 40%. In this context, a Computational Fluid Dynamics (CFD) program has been used to predict external convective heat transfer coefficients at external building surfaces. The simulations have been carried out using the building model presented in ANSI/ASHRAE Standard 140-2001 – Standard Method of Test for the Evaluation of Building Energy Analysis Computer Programs in the Building Energy Simulation Test (BESTEST). For the BESTEST house model, effects of wind speed and temperature differences between the surfaces and the external air have been analyzed, showing different heat transfer conditions and coefficients.