
Atmospheric Water Harvesting - rch
https://www.chemistryworld.com/features/atmospheric-water-harvesting/4011929.article#/
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somishere
They've been trialing this on a remote island on the GBR for a couple of years
now. They don't produce a lot of water, in the tens of litres per day I think,
but they work (and are fully solar powered). Agree it's a fairly edge use
case. [https://ladyelliot.com.au/sustainability/water-
conservation/](https://ladyelliot.com.au/sustainability/water-conservation/)

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qayxc
That looks awful compared to compact, simple and readily available
desalination units... [1]

On an island, desalination looks much more efficient and reasonable than these
contraptions.

[1] [https://www.foreverpureplace.com/500-GPD-Seawater-
Desalinati...](https://www.foreverpureplace.com/500-GPD-Seawater-Desalination-
System-Watermaker-p/swro-500.htm)

~~~
somishere
Absolutely agreed. LEI are using both systems. But still, given the tech works
(and current efficiencies aside), surely it shouldn't be written off so early
in the game? Also on anecdotal evidence the hydro panel water tastes a bit
better than the desal!

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TimSchumann
Every time I see articles like this I think ‘Great, so where are they going to
get access to unlimited free energy?’ That’s about what it would take for
‘Atmospheric water harvesting’ to be economically viable.

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alextheparrot
Wouldn’t dry, arid, sunny places be the perfect fit for this, then? Solar
power and a lack of preexisting water would probably make that scenario
economically viable

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AlotOfReading
The amount of energy you need goes up the less moisture there is in the air.
The ideal conditions are moist, cool places with cheap electricity. Tropical
conditions would have a shot at profitability, but you may as well desal
whatever's already there than condense it.

~~~
TimSchumann
Exactly this. Desalination and transport is aways orders of Magnitude cheaper
and more efficient.

I don’t see this changing at any point in the near future. It’s phenomenally
energy intensive to pull water out of the air in any quantity.

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floppiplopp
Oh, another "water from air"-scam, how original. The laws of thermodynamics
don't change. There's always a minimum of energy needed to condense water, and
it's a lot. That's it, there is nothing more to add. It it possible? Yes. Is
it viable at scale? No.

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Cogito
Not sure what you are commenting on here - this article is a review of three
different types of technology used to pull water from the air.

I found the discussion far more interesting than this dismissal suggests they
would be, in particular:

\- improvements in dehumidifier tech,

\- development of new dessicants that will potentially be more efficient then
dehumidification, and

\- new fog-catcher designs (fog catchers are already used as reliable water
sources)

There are a number of different companies mentioned, some of which have
dubious claims, so maybe one of those is the scam you are referring to?

The article seemed balanced to me, not promoting any one company or technology
with outlandish claims. It leads in to the discussion by saying "the majority
of these devices operate in the same way as mechanical dehumidifiers",
differing in two major ways two major ways:

 _Firstly, robustness – water harvesters are designed to be operated 24 /7,
rather than to cycle on and off. Secondly, drinking water quality controls are
built into the machines. ‘The coil is coated with a food grade coating so that
the water that’s collected isn’t exposed to metal contamination, and the air
filter is a much higher quality than in a dehumidifier,’_

And then it immediately jumps into why this is generally a Bad Idea

 _But even though this dehumidifier-like water harvesting technology has been
around for a while now, ‘the market is still very small’, explains Ruzhu Wang,
a professor of refrigeration engineering at Shanghai Jiao Tong University in
China. ‘The reasons are high energy consumption and initial investment costs,’
he adds. Another issue is water capture efficiency; especially in dry, desert
conditions where a water harvesting technology might be most needed. The
atmosphere must be humid for useful volumes of water vapour to be able to be
sucked up using these tools._

This is an area that seems to attract extravagant and unrealistic claims, but
I don't think that accusation holds up agains this article.

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pohl
Now we just need a droid that understands the binary language of moisture
vaporators, or at least one experienced in programming binary loadlifters.

~~~
kakkun
I believe all the droids were destroyed during the Butlerian Jihad, and the
windtraps are managed manually by the Fremen.

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beamatronic
Wonder what’s the cost to supply 1 person with drinking and bathing needs.

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aaron695
Zero Mass Water -BUSTED!
[https://www.youtube.com/watch?v=vc7WqVMCABg](https://www.youtube.com/watch?v=vc7WqVMCABg)

You can do your own research for the other _solutions_ presented in the
article.

I find the idea of groundwater recharge interesting.

We dump large amounts of water into the sea having used the Earth as a
Atmospheric Water Harvester. We need to be keeping all that.

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saluki
[https://starwars.fandom.com/wiki/Moisture_vaporator](https://starwars.fandom.com/wiki/Moisture_vaporator)

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whatiscomputer
I'll stick to my Fremen Windtraps thank you very much.

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asdflke
So the main thought is how can we get more water from the air. Clouds are
inefficient. The problem is in how we can extract usable quantities an leave
enough to be normal.

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garmaine
The ocean will replenish what you take out.

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spiritplumber
Didn't Thunderf00t debunk these already?

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pengaru
People defecating directly into their fresh potable water supply will find no
sympathy here when the taps run dry.

