On the impact urban modified albedo: comparing the thermal conditions and the night ventilation potential in urban and rural dwellings in Rome, Italy

Urban heat island is a well-documented phenomenon with relevant impacts at several levels. The present study investigates the potential of night ventilation for thermal comfort improvements in residential buildings in Rome, Italy, by dynamic analyses at the mesoscale and building level. The atmospheric model is implemented in the Weather Research & Forecasting Model (WRF), a state-of-the-art tool for meso-scale simulations, and validated against air temperature and wind speed. A number of increased urban albedo scenarios are calculated for July and August 2020. The datasets are used to simulate the building thermal performance using the TRNSYS 17 software. Results showed that high albedo can reduce the average city peak temperature by 2°C, depending on the albedo configuration. The impact on the indoor thermal conditions is a strong reduction of discomfort hours in the urban areas, especially if enhanced by the night ventilation, which also provides to significant reduction of higher temperatures in the built environment.