On top of global climate change, the urban heat island effect increases city temperatures and poses a great challenge for city dwellers, causing heat stroke and heat stress and increasing electricity consumption of air conditioning in summer, said Jiachen Zhang, USC Viterbi Ph.D. and co-author of a paper on cool walls published in Environmental Science and Technology.
This paper, showcasing research by David M. Wilson Early Career Chair in Civil and Environmental Engineering and USC Viterbi Associate Professor George Ban-Weiss, was used as a basis to formulate a national-scale building credit for LEED. The US Green Building Council now gives LEED building credits for using cool walls to reduce building energy consumption and mitigate urban heat islands. Read the full release here.
Zhang said: “The urban heat island effect refers to cities being hotter than their surrounding areas due to a variety of factors, including the fact that urban areas contain less vegetation and more impervious surfaces. Although the effects of solar-reflective “cool” roofs on urban climate have been well studied in previous research, we carried out the first study focusing on cool walls.”
Their research demonstrated that in Los Angeles County, cool walls were able to significantly reduce urban air temperatures and ozone temperatures.