Reflective ceramic glazes to fight building overheating: a study from the eLITHE project
In a recent study published in the Journal of the European Ceramic Society, a team of researchers from CSIC explored how the shape of crystals influences the ability of ceramic glazes to reflect solar radiation, helping to keep building surfaces cooler and reduce energy demand.
Buildings are increasingly exposed to overheating: conventional materials absorb sunlight, raising surface temperatures and increasing the need for air conditioning. Reducing solar absorption, especially in the visible and near-infrared wavelengths (which account for 95% of solar radiation), is therefore crucial to lower energy consumption and mitigate the urban heat island effect.
The researchers analyzed enamels based on scheelite (CaWO₄), a material that, thanks to its high refractive index, can ensure high solar reflectance. The results show that the shape of the crystals is decisive: elongated arrow-shaped crystals, obtained at lower firing temperatures, achieve higher solar reflection compared to bipyramidal crystals, which are predominant at higher temperatures.
This finding highlights how controlling crystallization processes is fundamental to designing reflective glazes for façades and roofs, capable of:
- reducing heat accumulation,
- improving building energy efficiency,
- contributing to urban comfort.
The work has been published in the Journal of the European Ceramic Society under the title “Scheelite-based highly reflective enamels with varied crystal morphology and its influence on the solar reflectance”. It contributes to the activities of eLITHE and supports progress towards its sustainability goals.
Photo credits Jack Price-Burns on Unsplash