Hacker News Reader

"If this paint can make any surface cooler than ambient, why isn't it used everywhere?" Condensation is a serious problem, and then also the fact that seven months out of the year in temperate climates you don't want your building's exterior envelope to cool off even faster!

View on HN

"According to an R&D director from the Suzhou-based venture, on a clear 30-degree (86 Fahrenheit) day, a treated tank’s surface temperature can drop by roughly 25 degrees"

All I see in their claim is ambient temperature 30C, while surface heated in sun easily to 55C (or even more) with this paint claiming 97% reflectance to keep it at ambient temperature or slightly above.

Obviously the paint can't make surface cooler than ambient.

radiative cooling can make it cooler than air temperature, it removes the heat through infrared radiation

Reply on news.ycombinator.com