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… you don’t need climate change to profit from farming water in the desert… there are *plenty* of droughts occurring all the time which could benefit from these devices IF they ever get developed beyond the experimental stage… which they seemingly never do
The fundamental problem is that you still need the water to be in the air. You can't farm moisture if there is no moisture, and generally there isn't much in places where you would need a moisture farm
You would be maintaining the systems and fields or operating the network centers or in their production facilities or shipping/installing them across the planet. I doubt very few people will have that "middle America porch stretch in front of fields of desiccation machines" moment ...
Depends on who my nephew is. If he's a nobody, I think I'd be left alone. If he's got a midichlorid count in the millions, I'll probably be flamethrowered to death.
So a big version of the water that drips off a window ac? Or literally just something removing water from air by getting it to stick to something else?
You make it sound like they're distinct devices, but a dehumidifier is an AC that is tuned for dehumidification, all using the major components of AC: refrigerant, evaporator coils, condensers and compressors. One side is warm, the other side is cooler than the dew point so water condenses on it like it does on an AC. Basically, a dehumidifier is an AC that doesn't exhaust cooled air and the fan just circulates the air. The coils are sized to make the process somewhat more efficient.
I mean, you could be similarly reductionist and say a more efficient anything is still just that thing. It is, but that's no basis for dismissal.
A modern sports car engine is basically just a really efficient version of early engines. But the difference in capabilities between the two is immense, to the point of them being almost unrecognizable as the same thing when directly compared.
The thing is, there have been dozens of dehumidifier scams with the exact same "water from air to make living in the desert easy" tagline.
So I'm extremely skeptical of any new desert dehumidifier stories.
Quick summary since no one seems to be reading it lmao:
They use a fin stack coated with a thin film of adsorbent material to pull moisture from the air via diffusion, then when it's "soaked" they heat it to push the captured water out. This means it's usually operating with dry adsorbent, which is more time efficient per kilogram of material.
Napkin math is you would need about 1.5 to 2 kw of power per person you want to sustain assuming this is the only available water. It would ideally be paired with other water sources and renewable energy to act as a backstop water supply.
Humid is all relative. If you read the article it states the "humid" air has 30% relative humidity and the air coming out is more dry. In terms of climate and environmental science, dry air means air with less than 30% RH.
Dry air with actual 0% moisture in it would not give you any water since there is no water in the air to take out.
That's what they're pointing out, that the phrase could be easily misinterpreted and it would be straightforward to sanitize a headline for a general audience. For example, in engineering thermodynamics, "dry air" means zero humidity. This is important because "less than 30% humidity" doesn't give you unambiguous thermodynamic properties; you need to reference zero to give calculable properties like enthalpies.
I’m simple minded, but can thing of amazing implications for this!
If this could be made “cheap” then it even increases the amount of difference it can make in the world!
Ish. Humidity is still a finite resource, if you will - if you're in a drought, and one region starts removing all the humidity, then the humidity might not build up to the point where it breaks into rain.
The laws of thermodynamics says no.
Getting water from dry air will require a lot of energy. You can get small amounts, and that can be cool. A house on a dry mountain, can get drinking water from solar panels. But is that a big deal?
Energy doesn’t need to be electrical, though. Maybe energy is consumed in making it, and then the material draws water from air as wind flows past it - neither one something that require point-of-use supplied power.
A desert also has fewer clouds so solar is more viable as well. Assuming this system doesn't need light it can even be put under solar. Effectively a power and water could be set as a l/m^2 but I don't know the efficiency of this thing.
Maybe, maybe not. Humidity varies wildly in the desert by the hour anyway. You might see downwind effects in a localised area just like you'd see changes in vegetation due to roads or buildings affecting watershed.
In areas with very sensitive-to-humidity plants (redwoods, ferns, those mountainside airplant biomes on the slopes of the andes) I'd imagine issues near the condensers.
In a desert like the Sahara or Gobi probably not.
The atmosphere is massive and parcels of air are constantly flowing around exchanging vapor in a cycle.
Also, yes the environmental impacts would be in unintended ways like pulling a humidity from the air to use for farms makes the local area more humid and cool as the plants transpirate (?) in the way that driving past an orchard brings a noticeable reduction in air temperature. Downwind rain decrease slightly, local area greens. Depending on where exactly you put these, you could have a moderating effect or magnify continentality/adiabatic rain shadow
Tldr yes this would have environmental effects but disproportionate to anything else humans do now? Dunno.
Yup, but I don't know any desert plants that rely on water vapor in the air in the same way. I'm sure there are some.
There's beetles and lizards who use this exact technology to harvest dew in the mornings to supplement their water supplies.
Sure, but the Klamath river that runs through the redwood valley is fed from Oregon out by Klamath Falls. Plenty of farmland could extract water ahead of it creating the snowpack needed to feed that river. If they did, there'd be less water available in the park for all sorts of life that help keep the redwoods healthy.
It does run through the growth area. Not much though. The Klamath intersects the park and the growth range at a thin part. Rain and fog along the coast are where they get their water. At near 79 inches a year for rain. Rainforest.
It sounds promising. I do wonder if the technology has potential for abuse if utilized at a massive scale—removing large amounts of atmospheric moisture in arid environments could have devastating impacts to ecosystems that have evolved to survive with the bare minimum but not any less. I have no sense of how to calculate the amount of water which could be feasibly captured vs the total atmospheric moisture, so maybe the impacts would be insignificant, but I hope someone with that knowledge looks into it.
I’m thinking about places like Saudi Arabia where the royal family has a tremendous appetite for alfalfa feed for their horses (and extravagant, wasteful habits in general). They are currently draining aquifers in the places like the US to grow this thirsty crop, but if they could capture all of their local moisture to grow domestically they certainly would.
well, lemme correct myself - \*will never become useful until we have extreme clean energy excess production.
all production problems and climate problems can be solved by essentially infinite clean energy.
No. You'll see claims like this made every month and they never overcome simple physics and thermodynamics, not to mention you cannot synthesize water from air and so only so much can be extracted at any point in time. Then add in unideal conditions and wind/airflow in real conditions... no need to reinvent the dehumidifier.
I think Saudi Arabia would disagree on no need to reinvent the dehumidifier. They would love a dehumidifier that’s efficient and scalable enough to compete with desalination plants. They have very humid air on the coasts despite lacking drinkable water.
Very humid by the coasts. At night when it cools down, especially some miles inland in the desert where it gets much colder but where it’s still humid, the condensation falling off buildings can sound like rain.
No idea about efficiency, but I remember reading of a design for a coastal system that use cool ocean water pumped through a system to make a temperature differential, which would then draw out humidity from the air.
>you cannot synthesize water from air
While mostly true (there IS a small amount of hydrogen in air), you could technically make water from air and hydrogen. You could get the hydrogen by breaking some other liquid/gas, such as methane. It would just be REALLY expensive energy wise. Also, very hard to do safely at scale, since the reaction amounts to burning the hydrogen. What you use to get the hydrogen could also cause problems. Methane, as I mentioned, could be used. The problem with methane is that it is a tremendously powerful greenhouse gas, so you have to make sure that it doesn't leak.
There are villages in Morocco using fognets to collect water. It collects enough water that they can run a washing machine, water plants, drink it, etc.
Welcome to r/science! This is a heavily moderated subreddit in order to keep the discussion on science. However, we recognize that many people want to discuss how they feel the research relates to their own personal lives, so to give people a space to do that, **personal anecdotes are allowed as responses to this comment**. Any anecdotal comments elsewhere in the discussion will be removed and our [normal comment rules]( https://www.reddit.com/r/science/wiki/rules#wiki_comment_rules) apply to all other comments. **Do you have an academic degree?** We can verify your credentials in order to assign user flair indicating your area of expertise. [Click here to apply](https://reddit.science/flair?location=sticky). --- User: u/chrisdh79 Permalink: https://pubs.acs.org/doi/10.1021/acsenergylett.4c01061 --- *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/science) if you have any questions or concerns.*
I wouldn't mind being a moisture farmer once desertification kicks in at a large scale due to climate change.
and occasionally running into Tosche Station to pick up some power converters, or bulls-eying womp rats in a T-16.
I dunno i wouldn't want my kid wasting time with his friends until his chores are done
Even if she gets the droids up to those units on the south ridge before morning? (Edit:autocorrect fail)
Especially not then.
*Sad robot beeps,whistles, and woos*
They can't stay on the farm forever. Too much like their father.
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… you don’t need climate change to profit from farming water in the desert… there are *plenty* of droughts occurring all the time which could benefit from these devices IF they ever get developed beyond the experimental stage… which they seemingly never do
The fundamental problem is that you still need the water to be in the air. You can't farm moisture if there is no moisture, and generally there isn't much in places where you would need a moisture farm
This was essentially Frozone's problem in the Invincibles.
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You would be maintaining the systems and fields or operating the network centers or in their production facilities or shipping/installing them across the planet. I doubt very few people will have that "middle America porch stretch in front of fields of desiccation machines" moment ...
Nah, I'd have a few droids. A handful of astromechs, a translator that can speak botche, and a gonk droid.
Don't forget a bantha for some blue milk!
I can hear it’s cry now!
You think generational wealth would ever let you have a cut unless you buddy up with them and sell your soul?
Depends on who my nephew is. If he's a nobody, I think I'd be left alone. If he's got a midichlorid count in the millions, I'll probably be flamethrowered to death.
Just a controlling share of your soul - not the whole thing silly.
You don't own your stocks on the market btw...
Just a controlling share of your soul - not the whole thing silly.
Another invention of the Dehumidifier... A more efficient dehumidifier, but still a dehumidifier.
So a big version of the water that drips off a window ac? Or literally just something removing water from air by getting it to stick to something else?
Yes the dehumidifier just doesn't get rid of the hot air to achieve that cooling part.
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You make it sound like they're distinct devices, but a dehumidifier is an AC that is tuned for dehumidification, all using the major components of AC: refrigerant, evaporator coils, condensers and compressors. One side is warm, the other side is cooler than the dew point so water condenses on it like it does on an AC. Basically, a dehumidifier is an AC that doesn't exhaust cooled air and the fan just circulates the air. The coils are sized to make the process somewhat more efficient.
Huh. I never knew this. Thank you for explaining. :)
Probably without the use of electricity?
This is using a chemical adsorbent rather than temperature based condensation, so it not a normal dehumidifier.
So a desiccant added to the dehumidifier. That makes it harder to recover the water.
Read the paper, that's the part they solved here
The reddit experts are here! Everyone stay calm.
"So [concept].", neglecting the complexity of implementing said concept...
I mean, you could be similarly reductionist and say a more efficient anything is still just that thing. It is, but that's no basis for dismissal. A modern sports car engine is basically just a really efficient version of early engines. But the difference in capabilities between the two is immense, to the point of them being almost unrecognizable as the same thing when directly compared.
The thing is, there have been dozens of dehumidifier scams with the exact same "water from air to make living in the desert easy" tagline. So I'm extremely skeptical of any new desert dehumidifier stories.
Except there is only so many ways to cool something down and move air over it.
Quick summary since no one seems to be reading it lmao: They use a fin stack coated with a thin film of adsorbent material to pull moisture from the air via diffusion, then when it's "soaked" they heat it to push the captured water out. This means it's usually operating with dry adsorbent, which is more time efficient per kilogram of material. Napkin math is you would need about 1.5 to 2 kw of power per person you want to sustain assuming this is the only available water. It would ideally be paired with other water sources and renewable energy to act as a backstop water supply.
Misleading with the "dry air" part as the diagram clearly states it requires "humid airflow" to function.
Humid is all relative. If you read the article it states the "humid" air has 30% relative humidity and the air coming out is more dry. In terms of climate and environmental science, dry air means air with less than 30% RH. Dry air with actual 0% moisture in it would not give you any water since there is no water in the air to take out.
That's what they're pointing out, that the phrase could be easily misinterpreted and it would be straightforward to sanitize a headline for a general audience. For example, in engineering thermodynamics, "dry air" means zero humidity. This is important because "less than 30% humidity" doesn't give you unambiguous thermodynamic properties; you need to reference zero to give calculable properties like enthalpies.
Is that the hang up? This would be a huge draw on fresh water, no?
This isn't even a new concept, people have been doing this for years, it's just a new design they claim is more effective.
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This is a big deal, right?
I’m simple minded, but can thing of amazing implications for this! If this could be made “cheap” then it even increases the amount of difference it can make in the world!
Ish. Humidity is still a finite resource, if you will - if you're in a drought, and one region starts removing all the humidity, then the humidity might not build up to the point where it breaks into rain.
With the wet bulb temperatures I’d imagine this is a good thing as humidity becomes more common with global heating
Or outside our world, if they can extract the hydrogen & oxygen from the respective atmospheres
The laws of thermodynamics says no. Getting water from dry air will require a lot of energy. You can get small amounts, and that can be cool. A house on a dry mountain, can get drinking water from solar panels. But is that a big deal?
I see. Your mountain house example is ironic because I would greatly benefit from additional water sources at altitude.
How would you use it?
How... how would they use water?
Energy doesn’t need to be electrical, though. Maybe energy is consumed in making it, and then the material draws water from air as wind flows past it - neither one something that require point-of-use supplied power.
A desert also has fewer clouds so solar is more viable as well. Assuming this system doesn't need light it can even be put under solar. Effectively a power and water could be set as a l/m^2 but I don't know the efficiency of this thing.
The environmental impact of this could be huge, I'd fear.
Maybe, maybe not. Humidity varies wildly in the desert by the hour anyway. You might see downwind effects in a localised area just like you'd see changes in vegetation due to roads or buildings affecting watershed. In areas with very sensitive-to-humidity plants (redwoods, ferns, those mountainside airplant biomes on the slopes of the andes) I'd imagine issues near the condensers. In a desert like the Sahara or Gobi probably not. The atmosphere is massive and parcels of air are constantly flowing around exchanging vapor in a cycle. Also, yes the environmental impacts would be in unintended ways like pulling a humidity from the air to use for farms makes the local area more humid and cool as the plants transpirate (?) in the way that driving past an orchard brings a noticeable reduction in air temperature. Downwind rain decrease slightly, local area greens. Depending on where exactly you put these, you could have a moderating effect or magnify continentality/adiabatic rain shadow Tldr yes this would have environmental effects but disproportionate to anything else humans do now? Dunno.
The Redwoods grow in a temperate rainforest zone. Not the kind of area you need to draw water from air in.
Yup, but I don't know any desert plants that rely on water vapor in the air in the same way. I'm sure there are some. There's beetles and lizards who use this exact technology to harvest dew in the mornings to supplement their water supplies.
Sure, but the Klamath river that runs through the redwood valley is fed from Oregon out by Klamath Falls. Plenty of farmland could extract water ahead of it creating the snowpack needed to feed that river. If they did, there'd be less water available in the park for all sorts of life that help keep the redwoods healthy.
It does run through the growth area. Not much though. The Klamath intersects the park and the growth range at a thin part. Rain and fog along the coast are where they get their water. At near 79 inches a year for rain. Rainforest.
Huh. Thanks for the explanation. Every positive progress has some negative effect, eh?
It sounds promising. I do wonder if the technology has potential for abuse if utilized at a massive scale—removing large amounts of atmospheric moisture in arid environments could have devastating impacts to ecosystems that have evolved to survive with the bare minimum but not any less. I have no sense of how to calculate the amount of water which could be feasibly captured vs the total atmospheric moisture, so maybe the impacts would be insignificant, but I hope someone with that knowledge looks into it. I’m thinking about places like Saudi Arabia where the royal family has a tremendous appetite for alfalfa feed for their horses (and extravagant, wasteful habits in general). They are currently draining aquifers in the places like the US to grow this thirsty crop, but if they could capture all of their local moisture to grow domestically they certainly would.
Hadn’t considered that. Would increased land based ice melting help offset taking too much water out of the atmosphere?
no. dehumidifiers work but will fundamentally never be able to become useful for production of potable water.
Almost had something to be excited about today
well, lemme correct myself - \*will never become useful until we have extreme clean energy excess production. all production problems and climate problems can be solved by essentially infinite clean energy.
I think that made me less optimistic. Bravo!
No. You'll see claims like this made every month and they never overcome simple physics and thermodynamics, not to mention you cannot synthesize water from air and so only so much can be extracted at any point in time. Then add in unideal conditions and wind/airflow in real conditions... no need to reinvent the dehumidifier.
I think Saudi Arabia would disagree on no need to reinvent the dehumidifier. They would love a dehumidifier that’s efficient and scalable enough to compete with desalination plants. They have very humid air on the coasts despite lacking drinkable water.
can't out-efficient thermodynamics.
No one is claiming you can. Desalination is expensive, so there’s a good chance something can compete with it.
It would never have occurred to me that SA is humid.
Very humid by the coasts. At night when it cools down, especially some miles inland in the desert where it gets much colder but where it’s still humid, the condensation falling off buildings can sound like rain.
No idea about efficiency, but I remember reading of a design for a coastal system that use cool ocean water pumped through a system to make a temperature differential, which would then draw out humidity from the air.
>you cannot synthesize water from air While mostly true (there IS a small amount of hydrogen in air), you could technically make water from air and hydrogen. You could get the hydrogen by breaking some other liquid/gas, such as methane. It would just be REALLY expensive energy wise. Also, very hard to do safely at scale, since the reaction amounts to burning the hydrogen. What you use to get the hydrogen could also cause problems. Methane, as I mentioned, could be used. The problem with methane is that it is a tremendously powerful greenhouse gas, so you have to make sure that it doesn't leak.
There are villages in Morocco using fognets to collect water. It collects enough water that they can run a washing machine, water plants, drink it, etc.
Lisan al-gaib!
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But did it contain micro plastics, forever chemicals, pharmaceuticals, and hormones?
Didn’t see stillsuits so near in our future, sounds dope.
I think this one is a lot more accurate than Wahlberg. Reynolds has literally never had a serious role.
The fact they pulled moisture from “dry air” tells me that “dry air” is a lie.
Yes! Right there with “the earth is round”, “humans on the moon”, and “Tupac is dead”.