UK professor says smearing yogurt on your windows can cool your home
Ben Roberts, a professor at Loughborough University, suggests that smearing yogurt on windows can help cool homes by reflecting sunlight. The low-cost method uses the yogurt's white color to bounce heat away, though practical concerns like smell and mess are noted.
Background
- Dr. Ben Roberts is a professor of chemistry at Loughborough University in the UK. He specializes in materials science and has been researching low-tech, passive cooling methods for buildings.
- The core idea: a thin layer of yogurt (or other protein-rich substances) applied to window glass can reduce indoor temperatures by several degrees. The proteins in the yogurt scatter and reflect infrared radiation (heat) while still letting visible light through — essentially acting as a cheap, DIY radiative cooling film.
- This matters because air conditioning is energy-intensive and contributes to climate change. Passive cooling methods that require no electricity are a growing area of research, especially as heatwaves become more frequent worldwide.
- The key mechanism is "radiative cooling" — the property of certain materials to emit heat as infrared radiation into the cold of outer space, even under direct sunlight. The yogurt trick is a proof of concept, not a consumer product; Roberts acknowledges it would smell and need reapplication. The goal is to inspire development of better, durable protein-based coatings.