Sunlight-reflecting “cool walls” have been shown to reduce energy costs by lowering heat gain in buildings. But they do more – reflective walls can also cool cities, fighting the urban heat island effect. The concept has new support from the U.S. Green Building Council (USGBC), which has issued a pilot credit for the installation of cool exterior walls in new homes, schools, and commercial buildings to mitigate urban heat islands.
A new study by researchers at Lawrence Berkeley National Laboratory shows that if every building in California sported “cool” roofs by 2050, these roofs would help contribute to protecting urbanites from the consequences of dangerous heatwaves.
Egyptian blue, derived from calcium copper silicate, was routinely used on ancient depictions of gods and royalty. Previous studies have shown that when Egyptian blue absorbs visible light, it then emits light in the near-infrared range. Now a team led by researchers at Lawrence Berkeley National Laboratory has confirmed the pigment’s fluorescence can be 10 times stronger than previously thought.
The energy and climate benefits of cool roofs have been well established: By reflecting rather than absorbing the sun’s energy, light-colored roofs keep buildings, cities, and even the entire planet cooler. Now a new study by Berkeley Lab has found that cool roofs can also save water by reducing how much is needed for urban irrigation.