Study finds yoghurt on windows lowers indoor temperatures during heatwaves

Researchers at Loughborough University in the United Kingdom tested an unconventional cooling method by applying a thin layer of low‑fat Greek yoghurt to the external surface of windows. In a month‑long trial involving two identical test houses, the yoghurt‑coated windows kept indoor temperatures on average 0.6 °C cooler, with differences reaching up to 3.5 °C on the hottest, sun‑lit days. Dr Ben Roberts, a senior lecturer in healthy building design, said the result was “positively surprising” and highlighted the technique’s potential to reduce heat‑related deaths during summer heatwaves.

Norwegian ventilation specialist Mads Mysen, director at GK and professor at OsloMet, noted that while the yoghurt coating works by reflecting part of the solar radiation and using evaporative cooling, the most effective strategy remains external shading such as blinds or awnings. He warned that interior curtains provide limited benefit and urged homeowners to combine simple shading with night‑time ventilation to keep homes comfortable.