Localized meteorological variables influence at the early design stage

A measurement campaign was set up in Lausanne. The objective of this study is to define the importance of using local meteorological variables in the design of urban spaces and in the evaluation of building energy use. Urban simulation tools typically use average climatic data to calculate the convection coefficient, the building thermal balance and the pedestrian comfort. For this purpose, two simulation tools, a CFD model and CIM (Canopy Interface Model) are used to simulate the meteorological variables on the EPFL campus, Lausanne, Switzerland. The simulation results from the CFD model and the CIM are compared with the experimental data and both models provide trends that are in very good agreement with measurement. CIM can provide high resolution vertical profiles without significant computational resources and thus be used at an early stage in the design phase. The CFD should be used when a more precise local evaluation is needed.