Evaporative Refrigeration: Zeer

[Eddaytona]

Just reading about a 5000 year old pub kept its food cold. Gee what a great idea for the Playa!

A zeer is constructed by placing a clay pot within a larger clay pot with wet sand in between the pots and a wet cloth on top.[11]

The device cools as the water evaporates, allowing refrigeration in hot, dry climate. It must be placed in a dry, ventilated space for the water to evaporate effectively towards the outside. Evaporative coolers tend to perform poorly or not at all in climates with high ambient humidity, since the water is not able to evaporate well under these conditions.

If there is an impermeable separation layer between the food and the porous pots, undrinkable water such as seawater can be used to drive the cooling process, without contaminating the food. This is useful in arid locations near the ocean where drinkable water is a limited commodity, and can be accomplished by using a pot that has waterproof glaze or cement[1] applied to the inner wall where the food is stored.

Extended operation is possible if the pots are able to draw water from a storage container, such as an inverted airtight jar, or if the pots are placed in a shallow pool of water. A strap can be used to tie the inner pot down instead of using sand to prevent it from floating.

https://en.wikipedia.org/wiki/Pot-in-pot_refrigerator

[Token]

Brewers been doing that for ages in warm climates to cool the fermenter.

I did a carboy in a beer party tub filled with water. Wrap the carboy with a cheese cloth to wick up water and evaporate, stick tub in laundry room under a ceiling fan.

Kept the wort between 50 and 60 when temperatures were 75+ in the house.

That’s how I modeled brewing a good SF steam beer - Ale yeast at near-lager temperature.

BTW, Mesopotamians built those to scale as a multi-level building underground that held ice year round.