The metric describing a material’s ability to reflect solar energy and dissipate heat is a crucial factor in mitigating the urban heat island effect and improving building energy efficiency. It represents a relative measure of surface temperature, considering both solar reflectance and thermal emittance. A higher value indicates a cooler surface under sunlight compared to a surface with a lower value under the same conditions. For example, a material with a value of 100 will stay significantly cooler than a material with a value of 0 when exposed to the same solar radiation.
Utilizing materials with elevated values offers several benefits. Reduced surface temperatures lead to lower ambient air temperatures, particularly in densely populated urban areas. This, in turn, decreases the demand for air conditioning, leading to energy savings and reduced greenhouse gas emissions. Historically, the measurement and application of these values have gained increasing importance as cities and building designers strive to meet sustainability goals and mitigate the impacts of climate change. Standards and certifications, such as LEED, often incorporate requirements related to this value to encourage the use of high-reflectance materials.
