U. WASHINGTON (US) — Condensation on a can of beer or soda provides more heat than the surrounding air, which means humid weather warms up your drink more than twice as much as dry heat does.
“Probably the most important thing a beer koozie does is not simply insulate the can, but keep condensation from forming on the outside of it,” says Dale Durran, professor of atmospheric sciences at the University of Washington.
He’s co-author of results published in the April issue of Physics Today that give the exact warming for a range of plausible summer temperatures and humidity levels. For example, on the hottest, most humid day in Dhahran, Saudi Arabia, condensation alone would warm a can from near-freezing temperature to 48 degrees Fahrenheit in just five minutes.