The basic theory is one that looks sound at first glance, but doesn’t hold up under scrutiny or real-life testing.
The theory is, things that are underground tend to be a constant, cool temperature. Water condenses at cooler temperatures. Therefore, pump air underground where it’s cooler than aboveground, and the water will condense out and become usable.
The reality is, pumping air underground causes the ground in that spot to warm up, until it matches the average temperature of the air being pumped in. End result: it might condense water out of the air for the first few hours, or even a day, but then it stops working.
(It also only works if the air is warm enough and carries enough humidity.)
Parts of that design look like something I’ve been toying with that uses peltier devices to achieve the right temperature, but the ground itself will never do the trick. And even then, the one I’ve been toying with is meant as a low-power dehumidifier, not a constant water source.
But, as far as the slow heating of the ground, sure, but the ground its one helluva heatsinnk. Given decnt conductivity, no way is that small container going to heat th e surrounding earth very much. Heck, stirring your coffee theoretically heats is, but with all the losses, you could never measure it.
The caves in NorthWest Arkansas have been doing this for a few years.
The basic theory is one that looks sound at first glance, but doesn’t hold up under scrutiny or real-life testing.
The theory is, things that are underground tend to be a constant, cool temperature. Water condenses at cooler temperatures. Therefore, pump air underground where it’s cooler than aboveground, and the water will condense out and become usable.
The reality is, pumping air underground causes the ground in that spot to warm up, until it matches the average temperature of the air being pumped in. End result: it might condense water out of the air for the first few hours, or even a day, but then it stops working.
(It also only works if the air is warm enough and carries enough humidity.)
Parts of that design look like something I’ve been toying with that uses peltier devices to achieve the right temperature, but the ground itself will never do the trick. And even then, the one I’ve been toying with is meant as a low-power dehumidifier, not a constant water source.
^^^^^ This Plus don’t intend to survive on it in arid regions, and in regions with high enough humidity there is usually surface water or ground water accessible and treatable. Sounds like someone is trolling for venture capitol.
This means that you might be able to successfully run a demo (for a short while), but long-term it will stop working. It would work if the bottom end was immersed in the water table, which could carry away the heat, but if you could do that it would be simpler to just have a well.
“until it matches the average temperature of the air being pumped in.”
False. The ground just keeps absorbing that warmth. Yeah it will warm up a little, but not that much.
Would have to dissipate the heat of vaporization and a bit more—perhaps in excess of 3300 BTU per hour into the soil to produce almost 10 gallons per day? Very wet soil???
Some buried pipe cooling systems can cool air without condensing the water vapor; but, only average about 14 BTU sustained per square foot of buried piping grid.