Urban Morphology Albedo and Physical Parameters Connection: Development of Material Aging Correlation with Ambient Conditions in a Mediterranean City, Greece

Urban heat island effects (UHI) account for the most challenging causes of increased energy consumption and carbon emissions. Among others UHI significantly impacts the overall energy performance of urban building stock and indoor-outdoor thermal comfort, especially, in the mediterranean areas.

Significant effort has taken place in the last decade to mitigate UHI island effects by manipulating material surface albedo. Reflectance of materials is mainly affected by factors such as color, roughness, the aging of materials. However, it is the actual impact of aging to materials’ surface albedo that is investigated in the current research. This might also include the practical benefits of intervening through maintenance at the surfaces of structural materials to mitigate UHI urban effects to energy efficiency and thermal comfort.

There seems to be agreement that the use of materials with high albedo offers a reduction of outdoor and indoor temperatures which is considered as the most important strategy in the mitigation of UHI. However, it has been also claimed that high albedo during heatwaves deteriorates sensed thermal comfort leading to a general complexity of how exactly material albedo interacts with the ambient environment and building stock.

While there is a significant amount of research that has been conducted on the relationship between albedo in building materials and energy consumption, temperature, and thermal comfort, there is limited research on the correlation between aging of urban surface coatings and albedo. The current study was conducted for 18 different locations in Xanthi, Greece. Experimental campaigns have been carried out and analysis of collected data employed to identify the relation between material surface physical properties (albedo, slope, surface temperature) and meteorological conditions (solar radiation, air temperature) as the main factors influencing UHI. It is also claimed that a “novel” function between physical parameters could be introduced to describe the impact of aging of materials.