Now this device that I'm going to show you only works when sunny and..:
I got to get started... What we are going to build is called a Zeer Pot. A fridge that runs on the sun, you'll need:
2 terra cotta pots (one larget than the other)
5' of thin plastic tubing
Waterproof Silicone
0.5 cubic feet of paver sand
Duct tape
Scissors
A large towel (Not shown here)
A gallon of water
Step 1: Cover the bottoms of the pots with some duct tape
Step 2: Plug the holes on the other side with the silicone and let it dry for four hours
Step 3: Fill the bottom of the pot with enough sand so when you place the smaller pot in it, the rims level out
Step 4: Get the tube, and plug one side with the silicone and let it dry for an hour
Step 5: Wrap the hose around the smaller pot and tape it there
Step 6: Cut some holes in the hose and test if water will run through it
Step7: Place the small pot in the large pot
Step 8: Fill the gap between the two pots with sand and put some sand on the bottom of the small pot
Step 9: Wet the sand, but don't put a lot of water or else the small pot will float and create a big mess
Step 10: Get your towel and soak it in water
Step 11: Fill the pot with a little bit more water
Step 12: Let it sit and wait for it to cool down. I stuck a thermometer in and out of the pots to compare the temperature
This works on the principle of water evaporation. When the water evaporates away, the heat is carried with it, and the inner chamber cools down. And this only works when the sun is beating down directly on the pot, and both the pot and towel have to be wet.
And how cold will it get...? See the next post for the chart.