Bring your building's temperature down by 36 degrees Fahrenheit using this simple, inexpensive trick

Summers are becoming increasingly hazardous, particularly in cities where the warming effects of tall buildings made of asphalt and concrete add to soaring temperatures, BBC reported. 

However, there is an easy and inexpensive way to cool urban landscapes with big buildings: retroreflectors. 

A study published in the journal Nature Cities on Monday shows that buildings with retroreflective material installed had a temperature decrease of up to 36 degrees Fahrenheit.

Elie Bou-Zeid, co-author of the study and professor of civil and environmental engineering at Princeton University, said that reducing building temperature is “very, very important” for pedestrians at street level “because those walls radiate a lot of heat on you.”

He added that chilling those surfaces by 36 degrees “will make you feel significantly more comfortable. It’s almost like being in the shade.”

Cities are significantly warmer than their surrounding suburbs and rural areas because of the way they are built. Tall buildings, dark roofs, asphalt and concrete absorb the sun’s rays and reflect its energy back into the environment as heat – the so-called urban heat island effect.

Urban designers have started to implement simple solutions to counteract the urban heat phenomenon, including painting roads white, planting more trees and building green roofs. But researchers say using retroreflective materials would have a more powerful cooling effect.

Retroreflectors take advantage of a simple concept: three mirrors in the shape of a cube corner reflect light back in the direction it came from. The same can be achieved with a mirror in the shape of a bowl.