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This solar fridge is a simple and quick diy project. The reason I decided to build it was because the fridge in your house takes up a ton of energy. This fridge is so cheap and reliable that it can be used in 3rd world countries. It takes about 15 to 30 minutes to complete and it only cost around $15 dollars.
Here is what you need
1 large clay flower pot
1 small clay flower pot
sand (I used about 1/4 of a bag)
towel
water
clay or plumbers putty (only needed if there is a whole in the bottom of the pot)
This solar fridge is a simple and quick diy project. The reason I decided to build it was because the fridge in your house takes up a ton of energy. This fridge is so cheap and reliable that it can be used in 3rd world countries. It takes about 15 to 30 minutes to complete and it only cost around $15 dollars.
Here is what you need
1 large clay flower pot
1 small clay flower pot
sand (I used about 1/4 of a bag)
towel
water
clay or plumbers putty (only needed if there is a whole in the bottom of the pot)
Step 1: Filling up the holes
The first step is to see if you have a hole at the bottom of your pot. If there is not a hole then you can skip this step. If there is a hole then take your clay or putty and firmly press it into the hole and cover it. Make sure there is no gaps for water to leak out.
Step 2: Even the pots
Fill the larger pot with a layer of sand. Then put the smaller pot inside the larger one and level the sand until both pots are at even height.
Step 4: Time to put the water in
Pour water into sand to saturate it completely. Once the water begins welling up instead of soaking in, you can stop.
Step 7: Usage of your fridge
Make sure you put your fridge in a shaded place. Also return once or twice a day and refill the sand with water and dampen the towel.
Step 8: How it works
The action that allows it to stay cool is the evaporation of the water surrounding the smaller pot. As the water evaporates, heat draws out from the smaller pot, keeping the contents inside much cooler the the surrounding environment.
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Confused with 'evaporative'
AKA: InSoNuLPEC device
Would a lid on top of the center pot help keep it cooler? Assuming the evaporation takes place in the outer pot.
Be sure to seach in google images.
Thanks for the instructable!
That's where physics comes in. Take a college level class and you'll see that it is not only possible, thanks to α = k / Ïc(p), but happens often.
http://en.wikipedia.org/wiki/Zeer_pot
Wikipedia:
The Coolgardie Safe is a low-tech refrigeration unit which uses the heat transfer which occurs during evaporation of water. It was named after the place where it was invented — the small mining town of Coolgardie, Western Australia, near Kalgoorlie-Boulder.
Coolgardie was the site of a gold rush in the early 1890s, prior to the Kalgoorlie-Boulder gold rush.
For the prospectors who had rushed here to find their fortune, one challenge was to extend the life of their perishable foods — hence the invention of the Coolgardie safe.
The safe was invented in the late 1890s by Arthur Patrick McCormick, who used the same principle as explorers and travellers in the Outback used to cool their canvas water bags: when the canvas bag is wet the fibres expand and it holds water. Some water seeps out and evaporates, especially if it is in a breeze, cooling the stored water.
This technology is commonly thought to have been adopted by explorer and scientist Sir Thomas Livingstone Mitchell, who had observed the way some Aborigines used kangaroo skins to carry water.
Principles of operation.
The Coolgardie Safe was made of wire mesh, hessian, a wooden frame and had a galvanised iron tray on top. The galvanised iron tray was filled with water. The hessian bag was hung over the side with one of the ends in the tray to soak up the water.
Gradually the hessian bag would get wet. When a breeze came it would go through the wet bag and evaporate the water. This would cool the air inside the safe, and in turn cool the food stored in the safe. This cooling is due to the water in the hessian needing energy to change state and evaporate. This energy is taken from the interior of the safe (metal mesh), thus making the interior cooler. There is a metal tray below the safe to catch excess water from the hessian.
It was usually placed on a veranda where there was a breeze. The Coolgardie safe was a common household item in Australia until the mid-twentieth century. Safes could be purchased ready-made or easily constructed at home.
The tray needed filling once a day or so ...held about 50 liters of water I think!
The charcoal stopped any odours too!
You will need to elevate a quantity of water above your roof on a tower next to your roof (I wouldn't put it actually *on* the roof) and find a source of water (your rain barrel on the ground). Install a solar pump with sufficient head to lift it to the upper tank. When your siphon system starts working, it will drain until the tank empties and the siphon breaks, and your solar pump will continue to putter along to refill it.
This would work GREAT with a grass roofed house!
YES you are correct this will function in more efficiently in dry climates.
The real model here resembles how a swamp cooler functions.
Swamp coolers as most of you know do not work in humid climates, just like refrigeration air conditioning is less efficient in dry climates.
The only problems I can see is that using tap water will cause mineral deposits on the condenser coils, while reusing the clean condensate could be complicated if there are separate evaporator and condenser units (since it would have to be pumped)