Climate change is severely affecting living conditions everywhere in the world. The congested metropolitan areas are particularly vulnerable to the urban heat island (UHI) phenomenon, wherein urban areas are higher in temperature than surrounding areas. These temperature variations can lead to intense heat waves and a drop in the quality of air, water and the general ecosystem. In commercial, industrial and residential buildings, the HVAC systems must work harder to maintain comfortable interior temperatures, leading to soaring energy costs.
Local governments strive to counter the heat island effect through technology researches and policy changes that encourage the use of green building materials, particularly cool roof coatings for building roofs.
Many states that are prone to UHI are forging ahead with new initiatives. California has enacted into law the adoption of cool roofs and other energy-saving construction technologies. The energy code defines, under the new Title 24 provision, a cool roof as one that shows reflectance values of at least .70, and emittance values of at least .75. The rating values come from the Cool Roof Rating Council (CRRC). When cool roof coatings drop the ratings values for roofs at these levels, the facility or household will need less cooling inside. And with less cooling requirements, the facility will save on energy bills by as much as 3%-10%.
The U.S. Department of Energy and the EPA has also launched a joint program called Energy Star that rates cool roofs similar to the CRRC.