For the past decade, passive daytime radiative cooling research has focused on how much a surface temperature can be lowered below ambient air through sunlight reflection and heat radiation into space. This unrelenting obsession has yielded not only impressive advances but also an unintended side effect: coatings designed to radiate as much heat as possible during the day keep doing so at night, causing buildings covered with these materials to become cooler than necessary and sometimes requiring additional heating to compensate.
In 2025, researchers at Monash University’s Department of Civil Engineering developed a ceramic that addresses both daytime cooling and nighttime overcooling. The material reduces surface temperatures by approximately 19.5 °C during the day while limiting nighttime overcooling to about 3.3 °C, performance the authors describe as ‘self‑adaptive’ rather than merely high‑performing.
