Every summer, city facades, roofs, and pavements absorb a large portion of solar radiation and act as heat reservoirs. This phenomenon not only raises temperatures in urban environments but also increases the need to cool buildings and homes, boosting energy consumption and related emissions.
To tackle this challenge, the COLD SURFACE project is developing new prefabricated enclosures that incorporate innovative photoluminescent materials. These solutions are designed to reduce heat buildup on facades and improve the thermal performance of buildings. The initiative, coordinated by URDECON and with the participation of AIMPLAS and the IETCC-CSIC, aims to achieve reductions of up to 2°C in the surface temperature of building envelopes and cut the energy demand associated with cooling by between 5% and 10%, thereby helping to mitigate the urban heat island effect.
The AIMPLAS researcher, Arsenio Navarro, explained that “the COLD SURFACE project promotes a new generation of architectural envelopes capable of staying cooler thanks to the use of advanced photoluminescent materials. These solutions are designed to harness part of the ultraviolet radiation and transform it into visible light, thereby reducing the energy that becomes heat and limiting the warming of sun-exposed surfaces.”
Materials that turn sunlight into a tool to combat heat
COLD SURFACE is researching innovative photoluminescent materials specifically tailored to the building sector’s conditions. Unlike other solutions that rely solely on solar reflection, these materials absorb part of the ultraviolet radiation and reemit it as visible light, reducing the energy converted into heat and promoting the cooling of surfaces.
“In addition, we are working on developing luminescent compounds that avoid the use of rare earths, considered critical raw materials for Europe, while improving their durability and compatibility with construction materials such as concrete,” Navarro noted.
As part of this research, new methodologies for simulation and characterization of these materials are being applied, generating knowledge that will facilitate their future adoption in the building sector.
As Gloria Pérez from the Eduardo Torroja Construction Sciences Institute (IETCC-CSIC) notes, “there are currently no widely adopted methodologies to evaluate this type of material for construction applications. The project will generate new testing and simulation protocols that will help better understand their potential to reduce building temperatures and combat the urban heat island effect.”
A solution to the urban heat island effect
Cities concentrate materials that absorb and store large amounts of solar energy, causing urban temperatures to be higher than those of their surroundings. This phenomenon, known as the urban heat island effect, increases energy consumption, reduces thermal comfort, and intensifies the impacts of heat waves on the population.
To translate this laboratory innovation into real-world construction practice, the project will develop full-scale demonstrators that will allow evaluating the behavior of these new envelopes under real-use conditions and across different seasons.
“One of COLD SURFACE’s main objectives is to validate this technology in real construction solutions and have data that facilitate its future market deployment. We want to develop enclosures that help reduce building heating and provide new tools to meet the challenges derived from climate change in cities,” says Antonio Jesús Martínez, URDECON’s Head of Innovation, the project’s coordinating company.
In addition to its energy and environmental benefits, the initiative will help open up new opportunities for the development of innovative, high-value-added construction solutions aimed at decarbonization and climate adaptation of urban environments.
