Here’s one for you: a cooling system that cools buildings down by using heat on sunny days.


It’s a project out of the King Abdullah University of Science and Technology in Saudi Arabia.

As Interesting Engineering explains it, the system relies on a natural phenomenon in which warm water will cool rapidly when salt crystals are added.

The system uses a particular salt, ammonium nitrate, which could drop the temperatures in a space from about 77 degrees Fahrenheit to 38 degrees in just 20 minutes.

That’s cool enough to refrigerate food as well as keep people comfortable in the summer.

And it can be reused.

Sunshine evaporates the water, and it can be recaptured through a solar still.

The ammonium nitrate can be introduced into that water again, cooling the space once more.

Plus, while the ways we typically keep food cold and air condition our homes and offices are pretty energy intensive, this one doesn’t need any electricity.

Which sounds pretty cool. Or hot. Or… I don’t know.

The National Toy Hall of Fame has released the list of finalists for induction.

The list includes board games like Battleship and Risk, Cabbage Patch Kids and American Girl dolls, and… sand.

Just sand.

I mean, you can make a pretty good castle with it!

Just don’t tell Anakin Skywalker.

No Electricity? A New Cooling System Uses Sunlight and Saltwater (Interesting Engineering)

2021 National Toy Hall of Fame Finalists 

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Photo by Maclej via Flickr/Creative Commons