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Inventor of Low Tech Fridge Wins Award
juju2112 writes "Mohammed Bah Abba of Nigeria won a Rolex award for his pot-in-pot invention. Here's how it works. You take a smaller pot and put it inside a larger pot. Fill the space in between them with wet sand, and cover the top with a wet cloth. When the water evaporates, it pulls the heat out with it, making the inside cold. It's a natural, cheap, easy-to-make refrigerator."
Time Magazine invention of the year for 2001
But, cut the guy a break. The cool thing here is that he's done it with readily available local materials which is pretty much one of the key features for a real engineer. To paraphrase the old saw:
Anyone can make you an evaporative cooler for $100; this guy's done it for $1.
It is not a Time Award but a Rolex Award and indeed very old news (2000!).
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The article didn't mention the effectiveness of the device. Say, on a hot summer day, RH of 80%, if we keep the pot under the shade, could we achieve 15 degree C. A temperature ideal for beer.
This is New?
.from a Mexican. (This serves as an object lesson to me. Even the experts might well overlook simple and obvious tricks that "every child" knows. Even if that expert is me). The water evaporates from the Tshirt drawing heat out of your body.
.for the enviroment. Much of the mythology surrounding the "magical" abilities of the Australian aborigine come from the same source, their technology being too advanced for a European to understand. It was lost technology to them.
No, not particularly. It's a very old trick to make cold water by putting it in an unglazed clay pot, which is porous, and allowing evaporation of the seepage to draw the heat out. I learned it from Mexican Indians 35 years ago and it was effective enough to make water cold enough to make your teeth hurt even in the tropical rainforest. It works even better in the desert where evaporation happens quicker due to the low humidity.
European bicycle racers have been wrapping their water bottles with a damp cloth covering to keep the water chilled for decades as well.
Until a couple of weeks ago I thought everybody knew you could keep cool by wearing a dampened T-shirt, and then I learned that the Pardy's, those paragons of sea lore and self-sufficiency without electrical power, had only just learned this trick. .
Wrap something damp around a pot, as is done with the water bottle, and the air inside the pot chills, as does anything inside the pot. Wrap a porous outer layer around the damp cloth, such as another pot, and you moderate the evaporation rate.
This "invention" seems to miss a few of the finer points of the device, thus requiring the damp cloth over the two pots. You need to use an unglazed pot for the outer one. Then you can even put a real cover on the thing and it still works. Better. Longer. Some sort of batting works better as a wick than sand, although sand will do and is certainly freely available.
I don't mean to denigrate this man's intellectual accomplishment. If he thought it up on his own from basic principles the intellectual feat is equal to the first man that did it.
But it really does amount to the reinvention of folklore that exists in one place in some other place.
And the people from Rolex think of it as a new invention because they are modern, mechanistic folk who don't know how to go about living without modern power and machines or what people who do not have such devices already know about doing so.
The Zapotec Indians I lived among for some months knew lots of tricks that had been handed down over thousands of years for surviving with nothing but what you could make with your own two hands. I've got a poncho just about eight feet from me right now that was woven by them on a backstrap loom they made themselves, with wool from sheep they had grown themselves, sheared themselves, carded themselves, spun themselves, using weaving techniques their ancestors had invented themselves (even though many people throughout the world had invented the same thing). Living with them for a few months taught me more about how to think about living than any number of survival books and hiking expeditions had ever done.
Many of the things they did appeared as magic to me, because I was just an ignorant Americano and their technology was sufficiently advanced. .
I was in Mexico in the late 60s (that's where I first heard Abbey Road). The Zapotecs are starting to lose it too now as they begin to sell their weaving to touristas so that they may buy Tshirts and blue jeans. Most of them buy neon colored acrylic yarn from the store now instead of using their own lovely wool, because the Americanos really like the bright "native" colors instead of the natural tones of wool.
Well, their lot will certainly improve with more money at their disposal, and I certainly won't begrudge them that. Doctors cost serious money no matter how "self-sufficient" they are, and they coul
We homebrewers have used this trick for a long time too.
... well, lagers.
If you're making a lager, you are supposed to keep it at a relatively cool temperature for an extended period of time while it
If you're not fortunate enough to have an extra fridge (with appropriate temperature regulator), or be living in a cold climate with a cool garage/basement, you can use this technique to keep it fairly cool.
Just put your carboy (or other fermenter) in a tub with a couple inches of water in it and wrap the vessel in a towel (my favorite was a thick Bugs Bunny terrycloth) with the bottom edge of the towel in the water. Just water your beer every couple of days and you're good to go.
He took a duck to the face at 250 knots.
I live in New Delhi, India-where summer temperatures of 45C are not uncommon. We have what we call 'desert coolers', which are much better than ACs for cooling. Imagine a large metal box with a big fan on one side and straw mats on the other three-which are wetted by water drawn up from the tank below by a pump. The air sucked in by the fan evaps the water, losing heat in the process, and becoming quite cool. I have a large one at home-and I've observed the room temp drop to 22-23C when its above 40 outside. This stuff consumes about 10-20% of the power consumed by an AC-so it's quite good. (power consumption depends on the wattage of the fan, u can put as powerful a fan as you like). They are also quite cheap to make, and it's almost like a cottage industry here-every summer, local shops stock these coolers in various sizes-huge 8' high ones with industrial grade exhaust fans, to cool large areas, to dinky little 'personal coolers'.
However, during the monsoons, or rainy weather-the humidity renders them useless, as evaporation on the straw mats reduces.
Oh, and clay pots have been used in India too, for generations, for keeping water cool-though not in the way mentioned.
"..One hosts to look them up, one DNS to find them, and in the darkness BIND them."
What is new about this is his effort. He maximized his design for over two years to get the maximum affect (prolonging the life of produce) for the least cost. Then he built two factories to produce them and distributed them to rural villagers for free (using his own money). Imagine the changes it made on a culture where food grown would only last 1-2 days once picked if it could now last a month or more!
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The real "invention" here is his efforts toward making a positive change in the villager's lifestyle. Obviously if someone is awarding $100,000 dollars there is more to it. You folks should do some more research before you nock it!! He plans to use the $100,000 to distibute the pots more widely and to increase his education efforts!
Learn before you look like a fool:
http://www.varaprasad.htmlplanet.com/custo