Modeling the urban geometry influence on outdoor thermal comfort in the case of Moroccan microclimate

• We evaluated the TEB model for the case of the Moroccan microclimate by experimental data.
• The impact of the aspect ratio was investigated on external thermal comfort using the PMV indicator.
• Both envelope with a high and low thermal capacity were studied.
• Recommendations for each climate zone and each envelope type have been proposed for Moroccan microclimate.

Thermal indoor conditions depend not only on the building envelope but also on the thermal outdoor conditions. It is therefore important that a great interest should be paid to outdoor thermal conditions in the future Moroccan urban design. In the present work we investigate the influence of the aspect ratio (AR), on both the heat fluxes of a canyon and the thermal comfort of pedestrians for three Moroccan climatic zones (Agadir, Errachidia and Fez). At first the Town Energy Balance model coupled with a turbulence closure model is evaluated using experimental data. The model is then used for determining the influence of heat fluxes generated by the canyon surfaces on the predicted mean vote (PMV) chosen as a thermal comfort indicator. The simulations results obtained using actual Moroccan envelope building characteristics show that in the three climatic zones it is best to promote a medium urban structure to insure a comfortable street for the two cold and hot seasons. The AR must be lower than 1.2 for Errachidia, between 2.5 and 3.4 for Agadir and between 1.2 and 1.9 for Fez. However, canyons having higher AR can also insure a comfortable climate using historical thick walls with high thermal capacity.