Evaporative refrigerator

I have seen  a "coolgardie safe" cool food by evaporation.
Also it can cool rooms with water being applied to the fabric via strips of cotton sitting in a water bath above and looping down the walls and fastened to the jute.
The water is drawn down by conduction.
From Coolgardie_safe#:
"The Coolgardie safe is a low-tech food storage unit, using evaporative cooling to prolong the life of whatever edibles are kept in it.
It applies the basic principle of heat transfer which occurs during evaporation of water (see latent heat and heat of evaporation).
It was named after the place where it was invented – the small mining town of Coolgardie, Western Australia, near Kalgoorlie-Boulder."
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Hi john;
Pretty cool item there (bad pun intended).
I would say it is a predecessor to a swamp cooler.
We use a  swamp cooler here and they defiantly work well  as long as you have low humidity.  (currently 22% at the moment)
A reservoir , a pump , a corrugated panel for the water to run down.
And a fan behind to blow the cool air in your home.
You must leave a window part way open to allow outside air in to the cooler for it to work properly.
,

Yes, variations of this technology will work as a cooling system. Always have. Evaporative cooling can be very efficient.

But: humidity is the other issue. Where does all that evaporated moisture go? In a very dry environment, no problem, it just dissipates. In damp environments, it can cause problems.

They dont work in damp environments.
I found this by Googling.

"Evaporative coolers are efficient for cooling spaces with low relative humidity.
The level of relative humidity in your home should stay between 30 and 50 percent for optimum efficiency of your unit.
You can still operate an evaporative cooler at humidity percentages up to 60 percent or more."

Evaporative coolers work more efficiently to cool the air when there is lower humidity.
It is best to operate them with the windows and doors iof the house open so air from the cooler is pushing outside all the time.
The increased efficiency of your unit will outweigh any losses from the cold air moving outdoors.
If the outside air is too warm you still need to keep the windows etc open, the cooler will lower air temperatures by about 13 deg. C at best.

They work best when the  humidity level is below 55 percent for optimum efficiency.
The ideal humidity level for health and comfort is between 30 and 50 percent,.

Hey John;
Yep that's a good description of how a swamp cooler works.
Of course I said all that in my first post.
With 20-30% daytime humidity around here... they work very well!
They would not work well at all in a humid environment , that's when you go with an A/C unit or go swimming in  the water!