Implementation of Ventilated Permeable Roof Solutions in Urban Microclimate Models: A Preliminary Study

Among urban heat mitigation strategies related to the building’s envelope, the performance of cool and green roofs has been assessed since decades. However, their effectiveness is guaranteed only if their functionality level is maintained over time through periodic maintenance or cleaning interventions. Moreover, they are not always applicable, due to architectural constraints. Ventilated and permeable tiled roofs (VPRs), easily applicable and extremely durable, also own environmental benefits related to the reduced incoming heat flows and related cooling energy use. However, their eventual impact on urban overheating has never been investigated, especially since their hygrothermal exchanges are not explicitly modeled into existing climate assessment tools. This work aims to implement a VPR in the urban climate model urban weather generator (UWG) and numerically evaluate its functioning compared to other roofing solutions. The implemented VPR model has been partly validated against experimental measurements on real-scale roofs. Simulation results show a good performance of the VPR in terms of surface temperature, internal gains, and heat waste released from the HVAC to the outdoor environment.