> Sorenson notes there is more than three quadrillion gallons of water in the air, which is essentially a massive untapped resource.<p>For what it's worth, air with low humidity can be pretty damaging. Lots of materials would become excessively brittle at very low humidities, causing them to break easily. This interesting white paper [1] suggests that, for most materials, the optimal humidity is between 40-60%.<p>Still, this is a very cool concept.<p>[1] <a href="http://www.descoenergy.com/pdf/Humidity%20How%20it%20affects%20Materials.pdf" rel="nofollow">http://www.descoenergy.com/pdf/Humidity%20How%20it%20affects...</a>
Background info: <a href="http://en.wikipedia.org/wiki/Air_well_(condenser)" rel="nofollow">http://en.wikipedia.org/wiki/Air_well_(condenser)</a><p>The device in India shown there produces 15 liters of water per square meter per year. The surface area of a bottle is, say, 500 square cm, or 1/20 of a square meter. That would produce about a liter in a year.<p><a href="http://www.iimahd.ernet.in/publications/data/2005-01-05gsharan.pdf" rel="nofollow">http://www.iimahd.ernet.in/publications/data/2005-01-05gshar...</a> talks of 0.042 liter per square meter per day, in extreme.y high humidity.<p>Clearly, some efficiency gains are needed w.r.t. those designs to effectively make the claim "water bottle tha fills itself". Whether that is possible, I don't know.
Hmm air can carry a few grams of water per kG of air [1] and 1kG of water is one liter, so if you can pull 1g of water out of each kG of air you need 1,000 kG of air. Stole this from wikianswers: "Each mole has a volume of 22.4 liters and a mass of 28.97g/mol at STP, therefore a cubic meter of air is 1.293 kg at 0o Celsius on the coast. An average mass of 1.2kg per m3 at room temperature and standard pressure is often used as a rule of thumb." so that would suggest about a thousand cubic meters of air flowing past this bottle's extractor area to get one liter of water out of the air.<p>No idea how long that would take though.<p>[1] <a href="http://en.wikipedia.org/wiki/File:Relative_Humidity.png" rel="nofollow">http://en.wikipedia.org/wiki/File:Relative_Humidity.png</a>
My question is what kind of contaminants (or none!) this process picks up - If you're getting your water from a polluted atmosphere (say, LA), what kind of pollutants end up in your water? Or does it produce "ultra-pure" water, leading to weird health risks like hyponatremia?
This may be a stupid question, but if the device requires power in order to move air over the water-collecting surface, would it work without power if it were outside in a breeze? Or is there something about the air flow in terms of its characteristics or location in/on the device that requires a manufactured flow?
Info I've found so far on rate of water capture:<p>(MIT, 2011) "In some field tests, fog harvesters have captured one liter of water (roughly a quart) per one square meter of mesh, per day. Chhatre and his colleagues are conducting laboratory tests to improve the water collection ability of existing meshes."<p><a href="http://web.mit.edu/newsoffice/2011/fog-harvesting-0421.html" rel="nofollow">http://web.mit.edu/newsoffice/2011/fog-harvesting-0421.html</a>
If I might channel my inner grumpy-old-man for a moment:<p>I find it curious that people who design nifty new devices are regularly referred to as "scientists". This is not science; it is <i>engineering</i>. Why not call it that?
This might be the first case of biomimicry on the front page :). This was one of the entries in our 2011 Biomimicry Student Design Challenge [1]. It's pretty exciting to see how far they've taken it from concept to funding [2] in a short amount of time.<p>[1] <a href="http://2011.biomimicrydesignchallenge.com/gallery" rel="nofollow">http://2011.biomimicrydesignchallenge.com/gallery</a> (#38 -- 5 rows from bottom in center)<p>[2] <a href="http://ben.biomimicry.net/uni/2012/biomimicry-design-wins-boston-college-venture-competition/" rel="nofollow">http://ben.biomimicry.net/uni/2012/biomimicry-design-wins-bo...</a>
This sounds nifty, but what I'd love to know is, what's the rate of filling, for an apparatus that's small enough to be roughly bottle-sized? Obviously many of the technical details (battery size, etc) are still being worked out, but I'm betting that rate of condensation is already known---and it's an important constraint.
This is one of those "didn't see it coming" technologies that really has the potential to change things. Could this disrupt the bottled water industry? Make it so that water pipes are a thing of the past ("wireless" for water)?<p>I realize that extraction rates are probably slow right now, but imagine this technology n years from now.
You can see more about collecting water out of the air at <a href="http://blogs.ei.columbia.edu/2011/03/07/the-fog-collectors-harvesting-water-from-thin-air/" rel="nofollow">http://blogs.ei.columbia.edu/2011/03/07/the-fog-collectors-h...</a> . Having lived in the Atacama desert I know there are already ways to do it and am very curious about the efficiency of this new system. In coastal northern Chile conditions are about as perfect as possible but it is still a slow process.
This could be good news for farmers who could perhaps create a closed loop within greenhouses to draw water from the air that the plants originally exhaled.
This is a fabulous technology, but we shouldn't get carried away. Firstly, this is another disruption of the world's water cycle, which we have already managed to a considerable degree, and if we manage atmospheric water extraction on a massive scale, we will wreak havoc with the climate (again).<p><i>Note, I said: if we do this on a massive scale.</i>