According to the EPA, Heat Islands are urbanized areas that experience higher temperatures than outlying areas. Structures such as buildings, roads and other infrastructure absorb and re-emit the sun’s heat more than natural landscapes such as forests and water bodies. Urban areas, where these structures are highly concentrated and greenery is limited, become “islands” of higher temperatures relative to outlying areas. Daytime temperatures in urban areas are about 1-7 degrees Fahrenheit higher than temperatures in outlying areas and nighttime temperatures are about 2-5 degrees higher.
An example of heat island effect would be the black asphalt surface radiating heat. During the day black asphalt absorbs the harmful UV rays of the sun and then at night releases it into the atmosphere. Heat islands increase cooling loads for buildings, and they result in high electricity usage as well as harm plants and animals that are sensitive to temperature change.
One tool that can help battle urban heat islands is an asphalt-based solar reflective sealcoat material. Based off a study done in partnership with the Arizona State University Urban Climate Research Center and the City of Phoenix, cool pavement sealcoats can assist in preventing asphalt thermal fatigue. Per the study, after a solar reflective sealcoat material was applied to asphalt, they found the average surface temperature during the day was on average 10-15 degrees cooler, the sub-surface asphalt was staying on average 5-15 degrees cooler and ambient temperatures at nighttime in neighborhoods were 1-2 degrees cooler. The U.S. Green Building Council supports cool pavement technology to help buildings meet their LEED Certifications. Cool pavement sealcoats help to keep ambient temperatures around buildings down and the solar reflectance reduces the electricity required for parking lot lighting at night, meaning parking lots are brighter at night using less lighting. Other advantages that cool pavement technology provides are:
Improved Air Quality
Improved Water Quality
Slowed Climate Change
With the average temperature around the world on the rise, cool pavement technology can be one tool to help BOMA members be part of the battle against urban heat islands.