This experimental paint reflects sunlight, emits heat and mimics sweating to cool buildings without air conditioning, even in the tropics.

Fei et al. designed a cement-based paint that cools both radiatively and through evaporation and that appears to keep buildings relatively cool even in humid environments. Although radiative cooling is effective at reducing temperature, it requires the material to be sky-facing. Designing a paint that also cools through evaporation allows the material to be effective when applied to the sides of the buildings as well.