Machine Condenses Drinking Water Out of Thin Air 438
longacre writes "A new $1,200 machine that uses the same amount of power as three light bulbs promises to condense drinkable water out of the air. On display at Wired Magazine's annual tech showcase, the WaterMill 'looks like a giant golf ball that has been chopped in half: it is about 3ft in diameter, made of white plastic, and is attached to the wall. It works by drawing air through filters to remove dust and particles, then cooling it to just below the temperature at which dew forms. The condensed water is passed through a self-sterilising chamber that uses microbe-busting UV light to eradicate any possibility of Legionnaires' disease or other infections. Finally, it is filtered and passed through a pipe to the owner's fridge or kitchen tap.'"
my broken refrigerator does this for free (Score:1, Insightful)
I have to keep a small bowl in the fridge which fills up with water every day from the leaking (frostless) freezer.
So my broken fridge is worth $1200 eh?
Re:Send this to the third world (Score:5, Insightful)
At 600 watt-hours per liter, you're going to be losing more energy to sweat and breathing than you could possibly get close to generating by hand.
Minerals? (Score:2, Insightful)
Regular tap water has a small amount of minerals, whereas distilled water (which this is, I presume) has none. Those minerals are actually rather critical:
http://en.wikipedia.org/wiki/Water_intoxication [wikipedia.org]
(Of course, regular tap water is dangerous too in laaarge doses.)
I have no idea if this is an issue... Anyone have a clue? :)
Also, three lightbulbs? Watts please... Found no proper specs on the site.
This could be very useful on ships... (Score:3, Insightful)
Nowadays, you either bring all your water along in tanks or use vaps to get fresh water from seawater.
If this works reliably and with that small amount of power, I can see ships and submarines adopting this to save weight and power requirements.
Re:Send this to the third world (Score:1, Insightful)
If we can solve the problem of giving it power (possibly with a hand crank and battery or some such thing), this should be sent to countries where drought is a problem.
Won't work.
Drought manifests itself as a lack of water, including lack of humidity in the air. If there is no humidity, then there is no water to condense out of the air by this device.
Why? (Score:3, Insightful)
The Element Four site doesn't say, but the inane "3 lightbulbs" remark from the Guardian article suggests it uses 200-300 W to produce 12 liters of water per day, if the humidity is >30%. Assuming 200 W, that's 1750 kWh/year.
The site markets this to First World households. But is that where its value lies? I get potable water from the tap, and so does most of Europe (and I pay E 1/m^3 instead of $0,30/litre). IDK about the States. The site mentions a ludicrous amount of bottled water, is that because US tap water isn't potable or is it just a fad?
The locations that most need this (hot and dry climates) I guess would fail the "humidity >30%" criterium.
The site only compares its efficiency with that of "bottled water" production, but what we need would be a comparison with e.g. a desalinisation plant.
Sorry for rambling a bit, but it adds up to this: is this condensor something the world needs, or just another "a fool and his money are soon parted" scheme?
Re:Send this to the third world (Score:5, Insightful)
Yeah, this is ONLY 200 times less efficient than desalinization.
Criminy.
I'll pass. (Score:1, Insightful)
Ignoring friction losses, and inefficiencies, You have to move 2250 joules to condense one gram of water, and that is work.... a lot of work.
Just 10 liters of water a day would take 22 million Joules, or 250 Watts (6000 Watt-hours, or 6 kWh)
The average person uses 500 liters a day, so that's 300 kWh, or about $30 a day.
They appear to be marketing this box to replace "bottled" water usage.... They filter solids, but they also don't say what they do about vapor-phase pollutants, such as benzene and other aromatic hydrocarbons that will also be in the condensate.
I would never drink condensate like this unless it were a life and death situation.
Not to mention, that in most places, dehumidifying the indoor air will cause people to need to turn up the heat, and use even more energy. Plus, air conditioning depends on phase-change (dehumidification) for efficiency. In dry air, it is much less efficient -- again, more energy.
Re:Send this to the third world (Score:5, Insightful)
this should be sent to countries where drought is a problem.
If drought is a problem I suspect there isn't going to be a whole lot of humid air to extract water from. "The mill ceases to be effective below about 30 per cent relative humidity levels,"
And after cranking that thing to produce 300W (about three light bulbs, and I'm guessing it means old-style, power inefficient, ones), you're going to need more than a glass of water.
And that's before we even consider the price tag.
Re:Who spends $1200 for a pimped dehumidifier... (Score:5, Insightful)
> I imagine the target market is people who live off the grid...
Such people usually use a clever invention called a well.
> ...a backup in case the grid fails.
It comes with a hand crank?
Snake Oil (Score:5, Insightful)
It really pisses me off that even supposedly "quality" newspapers like the Guardian just reprint some PR's press releases with marginal editing rather than doing even the most basic of reasarch or even, god forbid, any thinking.
TFA answers none of the pertinent questions about this device. But reading between the lines and doing a little thinking it's pretty easy to determine this device is going to be useless as anything but a gimmik.
Firstly, how much power does it use? "Three lightbulbs" says TFA, now as far as I'm aware the lightbulb is not a standard measurement for power consumption. But let's be generous and assume they're taling about standard 60-80W bulbs, that about 200W, give or take.
How much water does it produce? The article doesn't say, their website claims "up to" 12L per day, which I'd imagine is operating under optimium conditions (i.e hot air at close to 100% humidity). That's actually not a lot of water, and i'd imagine operating in any real conditions you could halve or quater that amount.
So adding up the numbers, that's 4.8kWh of electicty to produce about 6L of water. Or 800kwh/m^3. This is a ridiculously, hideously energy intensive way to make water, even desalination, which is seen as ecologically unfreindly, uses about 3kwh/m^3, or is about 250 times more efficient.
TFA also states this device is useless below 30% humidity, which removes the last reason one might consider using it, providing water where no other method is possible.
My point in all this is that doing about 2 minutes thinking, and exactly one google search, I have been able to determine that this thing is anything but ecologically friendly, and anything but economic. The journo writing this article for the Guardian, which for those of you who don't know it prides itself on being a "green" newspaper, couldn't even be bothered to do that and reprinted some PR's words wholesale, giving people the impression that what is in fact a toy for rich consumers who want to feel good about being "green" is some kind of ecological miracle device.
It should be a source of lasting shame to any newspaper to allow their editorial content to be used by some idiot for marketing purposes, sadly it's all too common and nobody even seems to notice the extent to which PR is taking over journalism.
Re:Minerals? (Score:3, Insightful)
Re:Seems kind of silly (Score:2, Insightful)
Humid air is actually less dense than dry air (as water vapour has 57% the density of air), so I think they'd be forced to use thin air by default.
Re:Hmmmm. The arid west (Score:3, Insightful)
Here's a hint. MOVE to Where The WATER IS LOCATED.
Incomplete information (Score:5, Insightful)
OK, it uses the same amount of power as three light bulbs when it's operating, but how long does it take to generate a liter of water? Without this, the "three light bulbs" is meaningless.
Re:Amazing! They've invented... (Score:5, Insightful)
My dehumidifier in my basement also uses "the electricity of about three light bulbs". The article claimed "$0.3 per litre". Lets run the numbers.
"Three light bulbs" is journalistic code for 300 watts. My electricity costs about 8 cents per kWh. $0.3 per liter implies it uses 3.75 kWh per liter. At 300 watts, it takes 12.5 hours to generate a liter of water. Or rephrased, it could fill a 2 liter soda bottle in about a day.
However, my $200 Chinese dehumidifier purchased at home depot, using the same electricity, easily fills its multigallon bucket in a day, at least during summer months. To help any NASA scientists here, multiple gallons is quite a bit more than two liters.
So, why does this greenwashing gadget cost five times as much as my dehumidifier but only produces about half the output? Surely it can't be continuously dumping 150 watts of UV sterilization light. Maybe those are metric kilowatt-hours as opposed to imperial kilowatt-hours.
The last line is also funny "reduces it from mid-afternoon when a blazing sun dries the air." The only way to dry air is rain, snow, mixing with drier air, dew, and frost. I am a firm believer in the conservation of mass, In a closed system if you evaporate a gallon at midnight I think it will still be there at noon. So, where, pray tell, does the water in the air go when the sun strikes it? Into a cave like a vampire? Outer space? Surely the "blazing sun" isn't visible from underneath a thunderstorm. I think in their inept little journalist way they are trying to say the device becomes vastly less efficient as the relative humidity falls. That would be no big deal, except that where ever there is high humidity, there is probably open water, and its usually cheaper to filter and desalinate open water than to dehumidify it. There is a certain perfection in a device that only works where you don't need it and can't work where you would otherwise need it the most.
Shows some potential (Score:1, Insightful)
FTFA:
The mill ceases to be effective below about 30 per cent relative humidity levels
I somehow don't see this as the device that will deliver much-needed water to bone-dry deserts.
Re:Snake Oil (Score:5, Insightful)
Another way to say it: the amount of energy required to produce 6L of water is about equal to half a liter of diesel. Burning half a liter of diesel would produce about 7L of water.
This device is even more ridiculous than propelling a sailing ship with a fan powered by a windmill...
Re:Send this to the third world (Score:3, Insightful)
Exactly.
Dehumidification = 600 Wh/liter
Desalinization = 3 Wh/liter
Pumping = 2 Wh/liter (cost to much of So.CA from Colorodo River)
So add in the pumping costs (assuming a LONG pumping distance) and it is still more than 2 orders of magnitude more expensive.
Only on Arrakis would this make sense.
Re:Why? (Score:2, Insightful)
Fad.
Yeah there are lots better ways to get water than this dehumidifier based water system. I've used air dehumidifiers, not to get drinking water of course but to get the air dry, but it's about the same thing, and the first thing I tell anyone asking about them is that they like the consume power... and lots of it.
Sometimes, municipal water can taste funny, and a lot of people have their own wells, so taste can be an issue there as well, but for the most part, water in the U.S. is fantastic.
No it's not, at least not compared to what I'm used to in the Netherlands. I've been in the USA a couple of times (mostly trips around Arizona, Nevada, California, but also have some experience in a couple of cities, Chicago, Dallas, New York). The water in a lot of places has a nasty chlorine taste to it.
Seriously the only place in the US where I encountered water of the same quality as ours was in Disneyland (Anaheim, CA). They have their own water system and their water is excellent.
Other than that I'd call the water in the US anywhere from "yuck", "drinkable", "okish", "good" even... but fantastic? My guess is you're either living in a part of the USA with water faaaar better than i've tasted overthere, or you havent had really good tap water yet.
Because bottled water probably sucks (Score:4, Insightful)
Really, most bottled water is just tap water, a plastic bottle, and marketing. I put my tap water through a tabletop filter pitcher before drinking it. Yeah, I'm a little bit paranoid about what might be in tap water.
And I can't stand that these news articles use a comparison such as "three light bulbs" (which in the middle of the growing popularity of CF bulbs is more vague than ever - 7W? 11? 13? 25? 50? 60? 75? 100??? What's an order of magnitude between friends, anyway?) instead of just stating the number of watts of electric power the thing consumes.
Re:Amazing! They've invented... (Score:4, Insightful)
Given that it's supposed to connect to your fridge or tap, I think their target market has access to water.
Re:I bought one last week for $135. (Score:5, Insightful)
I don't know if there are any good kits for steam distillation at home, can anyone point me to one?
And now you are drinking their pee (Score:2, Insightful)
Remember, all the water in the world has been used countless times and pee ain;'t even the worsed of it.
Re:Amazing! They've invented... (Score:3, Insightful)
The latent heat that must be removed when water vapor condenses to liquid is 540 calories per gram.
At a room/air temperature of 20 degrees C, 12 liters of water is 11,978 grams.
So, to condense that 12 liters of water would take 6,468,336 calories, or 27,063,518 joules,
which is equivalent to 7.52 kilowatt hours.
Now, a well made, typical Peltier cooler might have a coefficient of performance (ratio of heat removed to energy in) of 0.7, so it would require at least 10.7 kWh. That would be best case, at 100% RH, where the dew point and the air temperature are equivalent. The best Energy Star-rated dehumidifier with a comparable capacity (11.8 liters per day) has an energy factor (liters per kWh) of 1.3, so would consume about 9.2 kWh condensing that same 12 liters.
So, by my calculations, we're talking three 140 watt bulbs burning 24 hours a day to use the average, 10 kWh. And that's not accounting for the UV lamp (which could be very small, say 3 watts, for that volume).
I suppose in British Columbia, it might be possible to buy hydroelectric-generated electricity for the 3-4 cents per kWh that this thing MUST consume by the laws of thermodynamics.
Re:Just Vaporware (Score:3, Insightful)
or is it? [ucr.edu]
Re:Amazing! They've invented... (Score:4, Insightful)
"Three light bulbs" is journalistic code for 300 watts.
I was going to be snarky but I got to the party late. Screw it, I'll get snarky anyway (not to you; your comment makes it a bit more on-topic). I have CFLs, so this thing uses 75 watts? Or maybe the morons are talking about 600 watt street lamps, so it's 1800 watts?
This is slashdot. We know what a watt is. Saying "the power of three lightbulbs" at a nerd site is not only fucktardedly stupid, but insulting as well.
Someone mod the submitter down, "-1 not a nerd and stupid besides."