Fifty buck fridge keeps your food cool without electricity
We often say that Small fridges make good cities, but perhaps tiny fridges that don't need electricity are even better. The appropriately named Coolest Gadgets shows the Mitticool Fridge that Mansukh Prajapati designed as an evaporative fridge that would look good in your kitchen. We have shown many other evaporative fridges, but there are some interesting features on this one, including the trendy plastic door that lets you see what is inside (as it allows some heat gain, there is a price on everything.)
Prajapati describes how it works on the Mitticool site:
Water from the upper chambers drips down the side, and gets evaporated taking away heat from the inside , leaving the chambers cool. The top upper chamber is used to store water. A small lid made from clay is provided on top. A small faucet tap is also provided at the front lower end of chamber to tap out the water for drinking use. In the lower chamber, two shelves are provided to store the food material. The first shelf can be used for storing vegetables, fruits etc. and the second shelf can be used for storing milk etc. Cool and affordable, this clay refrigerator is a very good option to keep food, vegetables and even milk naturally fresh for days.
According to Coolest Gadgets, it sells for between $40 and $60.
Build your ownInstructables/CC BY 2.0
There are a lot of designs for evaporative fridges; you can build your own more traditional one out of two flower pots with this Instructables.
Powerhouse museum/Public Domain
Miners in Australia had their own version, developed in the 1890s. The Coolgardie safe made out of wood, tin and burlap. It would sit on a porch out of the sun but exposed to the breeze, which would evaporate the water from the burlap and cool the interior. They were in common use until the mid twentieth century. You can build your own with these vague instructions.
Here is another design from a prepper site for an iceless refrigerator.
The operation of this refrigerator is simple. Keep it in a shady place where the wind can blow over it. Keep the upper pan filled with water. The water is drawn through the wicks. and it saturates the cover. Cooling starts more quickly when the cover is dampened by dipping it in water or throwing water on it. The greater the evaporation, the lower the temperature inside the refrigerator.
Now what would be really cool is if someone designed an evaporative fridge with a solar panel and a fan so that you could control the amount of air movement and evaporation and maybe even stick a thermostat on it. But even without that, there are a whole lot of options.