The Impact of Passive Green Technologies on the Microclimate of Historic Urban Structures: The Case Study of Lodz

Abstract
Rapid population growth necessitates modifications of urban form, especially in city centers. Consequently, the correlation of the outdoor environment with the occupant’s behavior has profoundly changed. In this study, the authors describe a method, that allows for the estimation of the impact of passive green technologies on the microclimate of historic urban structures, taking into account the city-specific conditions. The Envi-met application, which is widely applied in urban climatology, was used to create the atmospheric processes simulation. Passive scenarios such as green roofs, living facades, and high greenery for chosen periods—warm conditions and the hottest day—were considered. It enabled an assessment of microclimatic outdoor conditions at the pedestrian (1.4 m) and living level (5 m). The results suggested that the highest temperature reduction was related to the tree scenarios (0.09 °C at 1.4 m and 0.18 °C at 5 m height for warm a period; 1.23 °C at 1.4 m and 1.31 °C at 5 m height for the hottest day). The thermal comfort was calculated through the usage of simulated output data. In our investigation, the maximum change in PET was 1.51 °C (for the warm period) and 5.41 °C (during the hottest day of the year). The findings have valuable implications for the design of the city’s structure.