579K views · May 5, 2017 · 42:44 · 0 HN recommenders · 7 mentions · discussed 2019–2026
Thunderf00t critiques the MIT and Berkeley metal-organic framework device that claims to pull water from air using only solar heating. He argues the energy accounting does not work and that such devices are essentially fancy dehumidifiers.
Why Hacker News points people here: HN uses it as the standard debunking to cite whenever a new water-from-air device is announced.
“The TLDW version is these devices are fancy dehumidifiers.”HN comment, 2022
“More about it here”
More on energy cost of air water harvesters
These dehumidifiers produce half a liter a day and need around 72 watt which is maybe 1€ per liter drinking water for my area The tech is cool but not really new or a solution to all water problems, the energy cost is relatively high. More about it here: this video
“You can't get water from air in deserts or places needing water of any practical, non military use”
> Crystalline nets harvest water from desert air, turn carbon dioxide into liquid fuel It's like we are stacking crazy, onto crazy, onto crazy. You can't get water from air in deserts or places needing water of any practical, non military use - Here's a start - this video We don't need to turn CO2 into fuel, just make fuel/energy without fossil fuels that's also used, and you're solving global warming in a amazing way. It's worth trillions, so it's always AMAZING to see some school kid or amateur scientist or researcher who just needs a little more research beat the multi nationals. It's a shame the multi nationals are to dumb to not hire school kids and these smart ideas people. Just shitty people who spend years studying at university then years working in the industry doing hard work to gradually make change.
“Thunderf00t has debunked a bunch of other enterprises doing water from the air”
Nope, there's no magic or free lunch. It depends heavily on local conditions which might not always be suitable. Thunderf00t has debunked a bunch of other enterprises doing water from the air: link link this video link etc
“He declares it a hoax, but ignores pretty much everything from the paper.”
Thanks for the links! Mostly scams and very bad science journalism indeed. However, he completely misses the mark in his video about the Science paper "Water harvesting from air with metal-organic frameworks powered by natural sunlight" [1]. He declares it a hoax, but ignores pretty much everything from the paper. Surprisingly, far down the comment section, there is a comment explaining that [2]. [1] link [2] this video
“The TLDW version is these devices are fancy dehumidifiers.”
None. Or alternatively, gathering Reddit/HN karma or channeling NGO funds into overpriced useless science projects instead of helping people. Thunderf00t has made a ton of videos about devices like this, for example: this video The TLDW version is these devices are fancy dehumidifiers. They need a ton of power, and lots of air humidity to be practical, which are exactly not the conditions these devices are advertised to operate in. And even then, the water they produce is dirty, so it needs to be purified and treated to be actually drinkable. Even if we solve all these challenges, it turns out that doing something dumb and low tech, like transporting drinking water on trucks is actually a lot more efficient. This is another one in the long list of devices designed to help those hypothetical poor people, like OLPC and the Gravity Light. It turns out these people have already solved these issues, and much better, usually with off-the-shelf alternatives and a bit of ingenuity.
“I believe everything in this video still applies.”
You can wear silica gel since about 1918 - only needs some heat to get the water out and cold to condense it. Then again, why would you want to wear your dehumidifier (ok ok water harvester)? Is it for excursions into damp areas, so that you can then return to your dry home to extract water? Then, I believe everything in this video still applies. this video
“It is a dessicant dehumidifier, useless for the same reason”
It is a dessicant dehumidifier, useless for the same reason as this MIT/Berkley thing from 9 years ago. this video
