Reflective or cool roofs have proven energy benefits, but did you know that their performance intensifies during a heat wave? Light membranes can cut the need for air conditioning and reduce temperatures in cities during high temperatures. By using a regional climate model with an urban model allowing roof reflectance to be adjusted, researchers found that the average temperature was cut by 50% more than under typical summer conditions.
The research was conducted by scientists from Lawrence Berkeley National Laboratory and Chinese researchers and performed in Guangzhou, China. This megacity near Hong Kong has an average temperature similar to that of Memphis, TN (around 72 degrees F.). With the U.S. experiencing warmer temperatures and heat waves predicted to increase, the researchers note that the free or inexpensive switch to a cool roof design during a retrofit offers substantial benefits for buildings as well as municipalities.