Originally published at: https://boingboing.net/2018/08/25/new-technology-sucks-water-out.html
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Good. Maybe now Uncle Owen will finally let Luke go into Tosche Station to pick up some power converters.
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Yeah, but where are we gonna find a droid that understands the binary language of these things?
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That R2 unit is in prime condition. A real bargain.
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A better way:
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It sounds good, but there’s always the phase change cost to go from water vapor to liquid. You can be clever about how you pay that, but you can’t cheat. (“In this house we obey the laws of thermodynamics!”)
That sounds like a generalization. Wouldn’t they need to hit the dew point? (Which might be 10C cooler in the conditions that they’re dealing with, might not.)
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What are the environmental effects of large scale dehumidification, though? I’m sort of assuming that it’ll produce an effect that’s like rainshadow, only with dew. That could be really bad if there’s a lot of life that depends on dew to survive.
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Right now, it sounds like the rain shadow is about a millimeter across, so your concern is premature.
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Commercial availability?
Wong envisions using a small battery to cool an element attached to the material. This would mean the harvester could operate beyond the range of typical fog nets – even in deserts.
Ruh-roh. I hope that he’s blue skying here, and New Scientist seized on it. Fog nets work because of mois… damp sea-level air being driven up a rise in altitude, bringing the dew point lower. (A clever way of paying the phase cost.) You just have to catch the condensing droplets, and a high surface area nano material should work for that. (How to get the water out of the material seems to be a bit vague.)
But desert air is a whole different problem. There you have to chill an awful lot of air to bring it down to the dew point before you can extract the water. The material could improve the efficiency, but the cost remains very high. Shifting that huge amount of BTUs is going to take more than a small battery. He’ll need to pull a lot more clever out of his hat to make that work.
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Literally the very first thing I thought of when I read the headline.
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The thermodynamics of getting water out of damp air are pretty damn terrible. And every once in a while a scammy-as-hell kickstarter will show up promising they will totally be the ones who do it and so far, they really aren’t. One of the biggest problems with dehumidifying air is that the ideal conditions to do this in are the ones just ahead of, uh, heavy rainfall. This rather defeats the point.
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Saw these guys on Ask This Old House:
https://www.zeromasswater.com/category/off-grid/
A: Solar, of which we have plenty. Way out of my price range, but if it wasn’t, with our super hard water it would be extra-nice.
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Fog nets are a special case where the conditions are just right: an on-shore wind blowing damp sea air up hills, dropping the pressure and temperature as it gains altitude, lowering the dew point and droplets condense out of the super-saturated air.
If any of the conditions aren’t right, forget it. Only some places will have dependable conditions for it.
In Chile, the project turned into a miserable failure, but not for technical reasons or collector efficiency.
I don’t see how people living on the margins will be able afford their fancy nano material.
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Sure, let the Dew flow to the thirsty masses.
Then are they going to pull insulin out of thin air, too?
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Seriously, 15 replies in. and you guys went “Tank Girl” before going to the classic?
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Wait… Tank Girl is not a classic?
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PICARD: I suggest that we build atmospheric condensers which could extract water from the air.
ADMINISTRATOR: I don’t mean to quash your very creative ideas but building atmospheric condensers would be a monumental undertaking. We could not hope to sustain such a project.
PICARD: Each community would be responsible for its own. Condensers could make the difference between watering our crops or watching them die.
ADMINISTRATOR: Well, I’ll be glad to pass along your idea. You’ll see that this kind of participatory government works for everyone. Be well, Batai. I shall see you next month. Good to meet you, Kanin.
BATAI: Go carefully, Administrator.
(The Administrator leaves)
BATAI: That went very well. I think he was impressed with you.
PICARD: But there’ll be no atmospheric condensers.
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…man I’m old…
Hrmph! You see, back in my day we had this weird David Lynch film, and it would be years and years later that Lori Petty starred in a somewhat doomed movie about a Jamie Hewlett comic. Fun fact: I won free tickets in college to see the premiere of Tank Girl. The theater was almost empty, and I spent what I would have spent on the ticket on bulk candy purchased at a drug store before hitting the theater. I watched it with a group of friends and a blood sugar level that would make a hummingbird jealous. I enjoyed it immensely.
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