Solar reflection and effect of roof surfaces material characteristics in heat island mitigation: toward green building and urban sustainability in Ha’il, Saudi Arabia

Abstract

Several materials have the ability to absorb, accumulate and transmit solar radiation to their surrounding environment. The thermal island effect and micro-climate of urban areas are subject to notable influence from the composition of materials within the city’s crust. The present investigation was carried out with the aim of assessing the impact of roofing and pavement materials’ properties on solar reflection and their potential to mitigate urban heat islands (UHIs). A study of an experimental nature was carried out on a total of 20 conventional materials that are commonly used in the construction of roofs, sidewalks, streets and rooftops in Ha’il, Saudi Arabia. The objective of the research was to investigate the impact of different urban surface materials on the rise of ambient air temperature in their vicinity. The present investigation aimed to assess the thermal performance of the specimens, with the purpose of ascertaining the impact of the thermophysical and radiative characteristics of the substances. The findings of the experiments indicate that the Solar Reflectance and temperature of the surrounding environment are primarily influenced by the color and substance of surface materials. Conversely, the texture’s condition has a comparatively minor effect. Both effective factors play an equally significant role in the overall mechanism of increasing the ambient air temperature. The results suggest that a significant proportion of the samples exhibit a maximum surface temperature exceeding 59.4◦C, while concurrently displaying a Solar Reflectance Index and albedo <49%. Meanwhile, the implementation of green roofs composed of various types of vegetation, including grass, can effectively alleviate the UHI phenomenon.