Air-conditioning a building with less energy consumption: this is the challenge taken up by a team from the University of Caen in western France, which has developed a cooling prototype presented as a solution for overheated urban areas, reports AFP.

The search for passive cooling systems worries many researchers around the world.

The structure developed in Cannes, called a “radiative cooling surface” (RRS), consists of several centimeter discs of silicon and niobium oxide made in northern Italy by Elettrorava in Turin, says one of the designers, Julien Cardin, a professor at the Ecole Nationale Supérieure d’Ingénieurs (ENSI) in Caen and an engineer at the University of Caen-Normandy.

Placed on the roof, it reflects the sun’s visible rays so as not to heat the building, and emits internal heat via infrared radiation into the space without heating the atmosphere. It can reduce the temperature inside the building by 30°C.

According to the developers, for greater efficiency, the device can be connected to a device that is supplied with a cooling liquid, such as water, through a pump.

Competing methods include the SkyCool Systems project, which has been under development at Stanford University in California since 2016.

“Our targets are overheated urban areas,” explains Julien Cardin, who starts from the observation that air conditioners consume too much energy and contribute to climate change.

“Air conditioners do not heat the atmosphere locally (creating heat islands around the building) as they do globally through CO2 emissions,” he notes.