Night Ice
August 1, 2006 3:04 PM   Subscribe

"The Bible describes how to make ice on the desert. Please describe the procedure and explain how it fits your knowledge of heat transfer."

Your assignment: make ice in the desert. Without electricity. Without extra chemicals. Without extra gadgetry or imports. Oh, and the temperature is about 55 degrees (13C). It can be done, there is science behind it. And yet we seem to have forgotten something that everyone used to know.
posted by jessamyn (43 comments total) 30 users marked this as a favorite
 
Up the west coast of British Columbia, we'd make ice with no electricity in a way that would actually work better in the desert, I'd bet.

We'd take a tall white 5 gallon bucket and put about 1/4 gallon of water in the bottom, and then sit a carton of milk in the water. Left in the sun, we'd come back a few hours later and the milk would be startlingly cool, occasionally having ice in it.
posted by Kickstart70 at 3:17 PM on August 1, 2006


An example of Doc's deep faith in God was the question on a quiz which asked: "What is the only chemical known to man which is less dense in a solid state than in a liquid state and why is that important?" The answer is water. Ice floats--if it didn't, then the oceans of the world would be full of ice at the bottom, and marine life would not exist.

Ah, clearly proof of God.
posted by odinsdream at 3:18 PM on August 1, 2006


*waits for stilgar*
posted by Smedleyman at 3:19 PM on August 1, 2006


What an amazing post. Thanks!
posted by maryh at 3:24 PM on August 1, 2006


Ditto, odinsdream. The very definition of a non-sequitur. Interesting post!
posted by peep at 3:27 PM on August 1, 2006


Left in the sun, we'd come back a few hours later and the milk would be startlingly cool, occasionally having ice in it.

Did you mean to type cheese instead of ice?
posted by nylon at 3:35 PM on August 1, 2006


No electricity, but you have ethanol and ether? Just use the ether to power a turbine that produces electricty!
posted by delmoi at 3:42 PM on August 1, 2006


Left in the sun, we'd come back a few hours later and the milk would be startlingly cool, occasionally having ice in it.

So, curdled milk will make you hallucinate? COOL!
posted by davelog at 3:43 PM on August 1, 2006


"What is the only chemical known to man which is less dense in a solid state than in a liquid state and why is that important?" The answer is water. Ice floats--if it didn't, then the oceans of the world would be full of ice at the bottom, and marine life would not exist.

Actually it life would have just evolved diffrently, probably never going multicellular and being able to survive being frozen.
posted by delmoi at 3:44 PM on August 1, 2006


I'd use a simple solar Stirling engine to power a second Stirling cycle engine as a heat exchanger. But that's just because I love Stirling engines.

More here, here, and here.
posted by It's Raining Florence Henderson at 3:48 PM on August 1, 2006


while googling around for some pictures of modern-day desert ice makers, I did find this interesting digg dispute, and this slashdot thread. I'd love to find a mythbusters-type account online of people actually doing this nowadays though.
posted by jessamyn at 3:49 PM on August 1, 2006


I'm not sure I can make ice, but I've gotten quite good at making water.
posted by Astro Zombie at 3:50 PM on August 1, 2006


How hot could a well tattied Seeroren house
get if a well tattied Seeroren house could get hot?
posted by unknowncommand at 3:51 PM on August 1, 2006


Evaporative cooling is well known, pretty much everywhere. Canvas water bags will keep your water cool in 140F temperatures, at a price of losing some of the water to evaporation.
posted by jellicle at 3:55 PM on August 1, 2006


Of course that would probably fall into the "gadgetry" category. I might also just build an old fashioned ice chest.
posted by It's Raining Florence Henderson at 3:57 PM on August 1, 2006


Ice Harvesting in 19th and 20th Century America:
"...ice was considered the first important agricultural product of the year being harvested in January and February."
Long live the ice box.
posted by ericb at 3:57 PM on August 1, 2006


I'd love to find a mythbusters-type account online of people actually doing this nowadays though.

asavage, I SUMMON THEE!
posted by frogan at 4:01 PM on August 1, 2006


wow, jessamyn, What an interesting post!

These are the vetiver root tatties used in old India -and today too. They are window blinds and water is trickled over them. The slightest breeze blowing through makes the air cool and fragrant. (Previously mentioned in this thread).
posted by nickyskye at 4:03 PM on August 1, 2006


while googling around for some pictures of modern-day desert ice makers, I did find this interesting digg dispute, and this slashdot thread. I'd love to find a mythbusters-type account online of people actually doing this nowadays though.

We've actually talked about that before.
posted by bob sarabia at 4:12 PM on August 1, 2006


Jess, this is a very cool post. I love the juxtaposition of engineering geekery and the bible. Very nice.
posted by caddis at 4:18 PM on August 1, 2006


Which one of the 11 links am I supposed to click on to find the answer? (click..click..click..) Sorry, I hate posts where you have to search for whatever it is the post is about. I had a long day... sorry, forget I was ever here.
posted by BillsR100 at 4:27 PM on August 1, 2006


Radiative cooling.

Pure Energy Systems wiki with articles about natural cooling.

It's Raining Florence Henderson, Impressive simplicity in the desert evaporating coolers.
posted by nickyskye at 4:29 PM on August 1, 2006


BillsR100, last link, "everyone used to know".
posted by nickyskye at 4:31 PM on August 1, 2006


I'm trying to remember the specifics of the ice machine in Theroux's Mosquito Coast.
posted by xod at 4:42 PM on August 1, 2006


"What is the only chemical known to man which is less dense in a solid state than in a liquid state and why is that important?"

Water. This is important as it tells us we have yet to discover gallium, acetic acid, antimony and most significantly silicon (thanks Wikipedia). As we've not discovered silicon and this is a crucial component of computer chips we can infer that Metafilter is a figment of my imagination, and therefore it's not unreasonable that everything is a figment of my imagination. Therefore I must be God.
posted by edd at 4:45 PM on August 1, 2006


<snark>You're doing this to avoid paying out $30, aren't you?</snark>
posted by matthewr at 4:52 PM on August 1, 2006


Wow, I had been wondering a couple of days ago about exactly this subject and here's the answer, and then some, thanks!

Also, thanks It's Raining Florence Henderson,
posted by MetaMonkey at 4:58 PM on August 1, 2006


A little more:
The Romans used to make ice in the deserts of North Africa or Palestine by taking advantage of the low humidity (and therefore the low temperatures at night). They would put what they wanted to freeze in a pit well-insulated with straw. The pit would be covered with highly-polished shields or other objects during the day, to reflect the heat of the sun; at night, the pit would be uncovered so that it could lose heat to the desert air.The same principle was used, for example, in British India. In times and places when the nights were cold, water would be poured into molds at dusk and allowed to freeze; then, at about 3 or 4 AM, the ice would be chipped out of the molds and rushed to an ice-house.
Yahoo Answers has a go
posted by MetaMonkey at 5:14 PM on August 1, 2006


In 21st. Century related news:

Ice-powered Air Conditioner Could Cut Costs
"Can an ice-powered air conditioner take the edge off scorching summer electrical bills?"
posted by ericb at 6:03 PM on August 1, 2006


This is cool (pun intended). Now how can I apply this principle to the keg in my basement?
posted by ZenMasterThis at 6:25 PM on August 1, 2006


Finally, modern ancient science explains Matthew 14:25 — Jesus was skating!
posted by rob511 at 7:07 PM on August 1, 2006


Ammonia and using solar power to distill it from water, then recombine with water for the cold effect.

Because, well, Dean Kamen hasn't shipped a stirling. And the 1HP Omnachron engine for $89 is nothing more than a year 2000 press release.
posted by rough ashlar at 7:38 PM on August 1, 2006


Fascinating post and linkset. Thanks jessamyn!
posted by peacay at 7:59 PM on August 1, 2006


Huh. I knew this already — it was filed in my head under "knowledge I might use if I were ever to become a Boy Scout and/or marooned on an alien planet / other dimension". Or if I wound up in the desert with plenty of water buy no ice, I guess. I figured it was the kind of thing that a lot of people kind of know but never use, like starting a fire with a bow, or panning for gold.

xod, IIRC, the Mosquito Coast ice maker was some variation on a propane-powered ammonia absorption refrigerator except probably not powered by propane. (Was it wood-fired?) Ammonia refrigeration was pretty dangerous even when not in the jungle. Szilard and Einstein spent a while inventing new refrigeration techniques in hopes of reducing the loss of life due to leaky home refrigerators. It's no wonder that CFCs, once they were invented, were so widely adopted as refrigerants — pity about the ozone layer, though.
posted by hattifattener at 8:37 PM on August 1, 2006


A couple of people have built their own air conditioners using ice water, copper tubing and an electric fan. Here's a big one and a little one. Links are from DIY:Happy.
posted by Tuffy at 10:18 PM on August 1, 2006 [1 favorite]


Radiative cooling is also why, on clear nights, frost will form on the ground that is not in shadow; e.g., no frost under a tree but frost outside of the tree's shadow. This is because the ground radiates its heat away to the sky—when the tree is in the way, the tree is about the same temperature as the ground and little cooling occurs. The emptiness of space, of course, is much colder. Thus the ground loses heat to the open sky and forms frost while the shaded ground does not. This is also why less horizontal and vertical surfaces on a car, for example, will not frost but the horizontal surfaces (e.g., the hood) will.
posted by Ethereal Bligh at 11:59 PM on August 1, 2006


No gadgets? Hmm, that rules the Crosley IcyBall and some firewood right out, then.
posted by scruss at 3:31 AM on August 2, 2006


For those who doubt me, try it out. If it doesn't work for you, THEN call me a liar. Until then, stick it up your ass.
posted by Kickstart70 at 11:35 AM on August 2, 2006


Ah, clearly proof of God.

Although the good professor didn't state it as proof, just a nice characteristic of the universe, I can't avoid beating this particular dead horse…
"It is demonstrable," said he, "that things cannot be otherwise than as they are; for as all things have been created for some end, they must necessarily be created for the best end. Observe, for instance, the nose is formed for spectacles, therefore we wear spectacles. The legs are visibly designed for stockings, accordingly we wear stockings. [...] they, who assert that everything is right, do not express themselves correctly; they should say that everything is best." — Candide
posted by Firas at 12:06 PM on August 2, 2006


I don't think charming old Doc Lewis would want readers of this thread to go away thinking water "is the only chemical known to man which is less dense in a solid state than a liquid state." Among just the elements, at least Gallium and Bismuth contract on melting.
posted by jamjam at 6:15 PM on August 2, 2006


Oops! Sorry edd, I skipped over your interesting post on first reading, somehow.

Now that I'm here though, Kickstart70, I was thinking about your white bucket in the sun. I can't see see why it would have to be left in the sun, but I can imagine that it would need to be a sunny day because the radiative temperature of a patch of cloudy sky should be much higher than blue sky, and that effect would be even stronger for patches of black and cloudy sky at night.
posted by jamjam at 6:31 PM on August 2, 2006


I think the bucket with water is relying more on evaporative cooling.
posted by caddis at 6:49 PM on August 2, 2006


hattifattener writes "Ammonia refrigeration was pretty dangerous even when not in the jungle."

Still wildly used. 90% of the RV fridges rolling down the road use the ammonia process and there are many commercial installations making use of the waste heat of steam and electrical generators to chill water.

The big gain in safety from Freon 174; was the elimination of truely nasty stuff like H2S
posted by Mitheral at 1:47 PM on August 8, 2006


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