Air Well - collecting water from the air

Thanks Hans. I can't wait to try this. Will post results when finished.

Wanted to bump this post in relation to a recent post on transpiration and water collection by Joel Cedar...

sweet

Joel, not sure if I would last a day in the desert. I still PTSD'ey and always have to have clean water with me at all times.

Super excieted to hear about air wells. Lived in the high desert for a
number of years and was stuck with about one inch of rain per year.
Sound like you do need some humidity though to make it work.
Not sure if those high desert areas have enough humidity.
Would love to know if any one on this forum has tried this and how it worked.

Here's a new, sculptural air well design. Just one photo here. Go to A Giant Basket That Uses Condensation to Gather Drinking Water to click through the entire slideshow.

THANK you somuch for posting that information on the water
sculpture project. Totally impressed with it!
Want to try them out here is California high desert,
Getting in touch with them.

Karen Crane wrote:THANK you somuch for posting that information on the water
sculpture project. Totally impressed with it!
Want to try them out here is California high desert,
Getting in touch with them.

Be sure to go back to page one of this thread for more air well designs, too. Some of them ancient.

I think that the key is to have something cold on a warm day. If that something is really large and really cold, it could create hundreds of gallons per day.

First, here is what a condenser from a dehumidifier looks like:



The job of the condenser is to be a cold thing where warm air passes across it, and then water condenses on the metal and drips off - thus filling the dehumidifier bucket throughout the day.

Next, pick the coldest spot on the property. A steep, north facing slope. The average temperature here is about 45 degrees. And Hait says that that sets the temperature at 20 feet down. But on a north facing slope, maybe the average temperature is more like 40.

So what if I put a piece of rebar 20 feet down and then connect a condenser to it just above the surface and then a bowl under that?

What if this is in a thick forest?

Jocelyn Campbell wrote:Here's a new, sculptural air well design. Just one photo here. Go to A Giant Basket That Uses Condensation to Gather Drinking Water to click through the entire slideshow.

A bit more:

Dumb question maybe but I'm not quite getting it...is the rebar a way of conducting heat away from the condenser to the colder earth 20 feet down so that it, the condenser, remains cold on a warm day?

By the way, this whole thread is really fascinating. We don't have rock on our property but we often have night/early morning fog even during dry spells and there are clearly more ways than rocks to collect this moisture. The brain cogs are whirring. thanks for all the contributions.

Sue Rine wrote:Dumb question maybe but I'm not quite getting it...is the rebar a way of conducting heat away from the condenser to the colder earth 20 feet down so that it, the condenser, remains cold on a warm day?

Yup!

Amber Beckerson wrote:This must be where Frank Herbert got the idea for "wind tunnel moisture traps" used by the Fremen in the "Dune" books. I always wondered how possible it was for that to actually work.

This has always fascinated me, and there is an ancient middle-eastern structure called a Qanat, which is more of a sideways well, but can also be used for cooling/air conditioning (that will inevitably collect water as well.) http://en.wikipedia.org/wiki/Qanat

Amber Beckerson wrote:This must be where Frank Herbert got the idea for "wind tunnel moisture traps" used by the Fremen in the "Dune" books. I always wondered how possible it was for that to actually work.

Dune has a shocking amount of dryland-appropriate technology in it. Probably most, if not all, was taken from historical references and sites as well as common sense for hot drylands - like anti-evaporation techniques and using the thermal mass of the earth or very thick walls to insulate humans and animals from temperature extremes.

Luke Burkholder wrote: This has always fascinated me, and there is an ancient middle-eastern structure called a Qanat, which is more of a sideways well, but can also be used for cooling/air conditioning (that will inevitably collect water as well.) http://en.wikipedia.org/wiki/Qanat

One of the places I would dearly love to visit is Yazd, Iran. Climate somewhat similar to Phoenix where I live - they get less water (2" to our 7") but we are hotter. They have an amazing qanat system along with other features such as wind towers to pull wind into buildings (often blowing across water in cisterns), and ice houses where snow could be packed and held from winter into summer. Amazing technology!











I'm also wondering how much air moisture/tree canopy coverage is needed to make the Warka Tower work. Spring is our driest season and we can easily go three months (April - June) with no rain. Our humidity reading yesterday was a whopping 3%. This will continue until we get closer to monsoon season in July.

I am very interested in building a (somewhat) large structure with a tank at its basin for purposes of harvesting water. On my property, I have about 18" of top soil before hitting bedrock, which makes for a great foundation but will prove to be very costly in terms of a septic tank system and digging a regular well. Up to this point, I had been planning on trying to make due with rainwater harvesting (and still plan to), hugelkulture and irrigation for the plants, and purchasing the power-consumptive "Big Dripper" machines which essentially serve the same purpose as an Air Well for emergencies. For potability, I'd planned on multiple tanks and at least two UV purifiers.

This has the potential to change a lot of that, and cut down the considerable startup expense. But, I have two questions...

#1) Does anyone know where I could find a diagram of how to create such a structure, similar to the one in France?

#2) What preventive steps would work to keep the channels the air flows through (read: pipes and the like) from becoming home to hornet's nest that obstruct and/or contaminate the airflow and potentially the water?
And how to keep the water from becoming contaminated in the basin, if it's necessary for it to flow essentially directly into it?

I love the idea. It fascinates me. And, to be honest, it already has me re-thinking some of my other ideas unrelated to this post. But for the purposes of an actual Air Well, I'd love to hear some ideas for the above concerns to make it manageable and plausible. Thanks!

I am also interested in building something to collect fog water. I am in California with the drought but where I live we have thick fog almost daily! in some of the forests here when the fog is thick it drips off the trees. the trees act as fog collectors. I have found this thread really fascinating and also exciting.

Olivia Helmer wrote:I am also interested in building something to collect fog water. I am in California with the drought but where I live we have thick fog almost daily! in some of the forests here when the fog is thick it drips off the trees. the trees act as fog collectors. I have found this thread really fascinating and also exciting.

Geoff Lawton states in his online PDC that in drylands, you can increase your precipitation up to 80% by planting capturing condensation from trees. In order for this to work in very dry climates, one has to plant a sufficient number of trees which I take it depends on where you are. It is fascinating and thought-provoking. I think Tucson is on the right track with all their streetside stormater harvesting and all the trees they're growing with that harvested "waste" water. They'll eventually increase tree canopy coverage from 5% to 25% and will probably begin to see that condensation effect (and UHI mitigation!) for the entire city at that point.

Jennifer Wadsworth wrote:
Geoff Lawton states in his online PDC that in drylands, you can increase your precipitation up to 80% by planting capturing condensation from trees. In order for this to work in very dry climates, one has to plant a sufficient number of trees which I take it depends on where you are. It is fascinating and thought-provoking. I think Tucson is on the right track with all their streetside stormater harvesting and all the trees they're growing with that harvested "waste" water. They'll eventually increase tree canopy coverage from 5% to 25% and will probably begin to see that condensation effect (and UHI mitigation!) for the entire city at that point.

I have seen some videos about how trees help in drylands. I have been thinking about everything you said since I read it. My property has many bishop pine trees and I am on the edge of a bishop pine forest although there are also many other types of trees growing here. madrone, bay laurel, oak and others I don't know the names of. Here I never see the water dripping off the trees in heavy fog but a few miles from here the forest is mostly monterey pine trees and there I have seen water dripping off the trees in very heavy fog. I have only lived here a year and when I saw the water dripping from trees it was several years earlier on a bike ride. my first year here is the dryest year california has had so it is possible that in this past year the fog has just not been that extremely thick at a time when I was outside to see it drip off the bishop pines. I am wondering though if monterey pines are better than bishop pines at collecting water. 1/3 of the water collected for this community comes from fog that condenses on trees and the rest is from rain. I will have to try and find some local people who know more about the trees than I know and ask them if monterey pines collect more water than bishop pines do.

Olivia Helmer wrote:1/3 of the water collected for this community comes from fog that condenses on trees and the rest is from rain. I will have to try and find some local people who know more about the trees than I know and ask them if monterey pines collect more water than bishop pines do.

Olivia - keep us posted on what you find out! That would be fascinating.

Recently saw this new invention on air to water.


A Giant Basket That Uses Condensation to Gather Drinking Water | Design | WIRED
image
A Giant Basket That Uses Condensation to Gather Dr...
Vittori hopes to have two WarkaTowers erected in Ethiopia by 2015 and is looking for financial rainmakers who'd like to seed these tree-inspired structures across t...
View on www.wired.com

http://www.wired.com/wp-content/uploads/images_blogs/design/2014/03/warka-01.jpg

So, here's a company that is using a wind turbine to create power to run it's own built-in condenser and heat exchanger, etc... 1,000 liters per day!

http://www.smartplanet.com/blog/intelligent-energy/a-turbine-that-makes-water-from-the-desert-air/14701

my husband told me that he read that metal roofs are very good for collecting dew and that when they are well insulated the output of water collection doubles. standing seam metal roofs are also supposed to work really well with solar panels. we need to replace our roof in the next few years and are hoping to figure out a way to have the money for a standing seam metal roof not just for these reasons but also because they last a long time and are better in a fire than the cheap tar paper roof we have now. we live in a pretty high fire danger area.

the humidity here year round is high and we run a dehumidifier in the house anytime it is cold enough that the doors and windows are closed. that collects quiet a lot of water.

my husband sent me these links. not sure if they are already posted in the thread

https://en.wikipedia.org/wiki/Atmospheric_water_generator


and they sell things like this solar powered atmospheric water generator http://store.ecoloblue-world.com/41-eb-30s-deluxe-solar-kit.html

amazon.com even has them http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias=aps&field-keywords=Atmospheric+water+generator

a neighbor who works for the local water company my little town has offered to give my family a tour to see how the water is collected here. next time I see him or my husband sees him we will try and find a time to do that and I can also ask him about the different types of trees and which collect the most fog. He may not know but he probably can tell us who will know.

paul wheaton wrote:I think that the key is to have something cold on a warm day. If that something is really large and really cold, it could create hundreds of gallons per day.

First, here is what a condenser from a dehumidifier looks like:



The job of the condenser is to be a cold thing where warm air passes across it, and then water condenses on the metal and drips off - thus filling the dehumidifier bucket throughout the day.

Next, pick the coldest spot on the property. A steep, north facing slope. The average temperature here is about 45 degrees. And Hait says that that sets the temperature at 20 feet down. But on a north facing slope, maybe the average temperature is more like 40.

So what if I put a piece of rebar 20 feet down and then connect a condenser to it just above the surface and then a bowl under that?

What if this is in a thick forest?

I think the idea is sound. When you think about it, it is just basic physics. However, I have two issues that I would want to address, if it were me doing this:

1. The amount of water one can get out of the air is dependent on the air temperature. Warmer air holds more water. If I place the condenser where the air temperature is 40 degrees, will this reduce the amount of water I can get? It seems to me that I would want to put it where the air temperature is warmer so that there is more water to pull out of the air. Obviously, I would not want it where the ground is going to heat up too fast, but I think I would want to strike some kind of balance to maximize air temperature while minimizing ground temperature and taking into account the thermal inertia of the ground.

2.I would want to make sure that, by using a condenser similar to the one shown in your post, I was not setting up some kind of legionella factory or something. I am sure this could be done, but I would want to make sure I did my research before installing the system.

Also, I think it would be cool to put temperature sensors at different places along the length of the rebar when you install it, to see how well the rebar draws away the heat.

paul wheaton wrote:I think that the key is to have something cold on a warm day. If that something is really large and really cold, it could create hundreds of gallons per day.

First, here is what a condenser from a dehumidifier looks like:

The job of the condenser is to be a cold thing where warm air passes across it, and then water condenses on the metal and drips off - thus filling the dehumidifier bucket throughout the day.

Next, pick the coldest spot on the property. A steep, north facing slope. The average temperature here is about 45 degrees. And Hait says that that sets the temperature at 20 feet down. But on a north facing slope, maybe the average temperature is more like 40.

So what if I put a piece of rebar 20 feet down and then connect a condenser to it just above the surface and then a bowl under that?

What if this is in a thick forest?

That's an interesting idea but it wouldn't work. First off, rebar isn't thermally conductive enough to pipe the cold up through the ground well enough to make dew. You could use a heat pipe but that's expensive and it would have to run with the evaporator above the condenser which works badly. Even then that would require that the dew point must currently be above the temperature that you're piping up, and that depends on the humidity.

There are no modern air wells built using massive structures because massive structures cannot stay cold enough to produce significant water (a giant tower for 5 gallons a day?), and they cannot get cold enough if they are only cooled by air (which may not fall below the dew point at all). Instead, modern air wells use panels that have a small mass and radiate heat quickly to the sky, like an inverse solar panel. This can be extremely simple too. For example, a panel of sheet metal set at an angle open to the sky and insulated on the bottom will produce dew consistently at night. The same kind of sheet metal used for metal roofing can be used, and the effect is commonly seen on metal roofs. There is also a material called OPUR foil which was made specifically for condensing dew and works even better (and supposedly is even cheaper than sheet metal).

Here is an article on modern attempts to draw water from air. It was published in 2008.

http://www.dailykos.com/story/2008/04/20/499240/-Creating-Drinking-Water-From-Air#

Here is another article. Interestingly, this one has a section about half way down that discusses Chinese scientists researching why spider silk is so good at condensing water from the surrounding air.

http://blogs.ei.columbia.edu/2011/03/07/the-fog-collectors-harvesting-water-from-thin-air/

I'm liking the idea of catching dew/transpiration/fog with spider silk A LOT. Light. Flexible. Portable.

paul wheaton wrote:I think that the key is to have something cold on a warm day. If that something is really large and really cold, it could create hundreds of gallons per day.

First, here is what a condenser from a dehumidifier looks like:



The job of the condenser is to be a cold thing where warm air passes across it, and then water condenses on the metal and drips off - thus filling the dehumidifier bucket throughout the day.

Next, pick the coldest spot on the property. A steep, north facing slope. The average temperature here is about 45 degrees. And Hait says that that sets the temperature at 20 feet down. But on a north facing slope, maybe the average temperature is more like 40.

So what if I put a piece of rebar 20 feet down and then connect a condenser to it just above the surface and then a bowl under that?

What if this is in a thick forest?

Paul,
I think you need to insulate the top few feet of your heat sink. Might also want to use a fluid instead of a metal (I would use aluminum, not steel, but copper would be even better...) and then use the thermal difference to cause the fluid to flow. I think that your rebar would have gained a lot of temperature by the time it is 12 inches above the ground...

But it is a good idea, and if you can hook up a 10 watt solar panel and a small pump you could do it with fluid. Still relatively inexpensive.

Richard

Here is an interesting design for an air well that I came across today. It includes a wind turbine to pull the air through the system.

I have a metal roof on my home here in Boise. I set up a portion to collect rainwater (Ooh, illegal!) which it does well. I also notice that in spring and fall when we have humid air and cool nighttime temperatures we get quite a bit of dew collection as well. Our average relative humidity is 77.92% with annual precipitation of 12.1 inches.

Missoula is a whopping 84.7%! Phoenix 79.8%

(http://www.usa.com/phoenix-az-weather.htm)

So...maybe?

What you are trying to achieve is the dewpoint condition where temperature and relative air humidity cause the condensation of water vapor to liquid (dewpoint).

I would think, like others have suggested, that the rebar idea would fail, as I believe there is some physics law that causes heat to dominate over cold making the rebar track heat inward instead of bring cold outward (super scientific terms there!)

All my experience suggests that a liquid is the preferred medium for energy transfer as in a ground-water loop heater. Currently, folks are using low-temp windshield washer fluid.

Still not sure you are going to get a big boost, as the Wofati theory holds that the internal earth temp is a stable 54 degrees.

So then I am thinking:

54 degree surface temp at the earth to condenser surface loop, 80% relative humidity (Missoula)...according to this chart, once the outside air cools to about 65 degrees, you should get dew forming...

https://en.wikipedia.org/wiki/Dew_point


That's why my metal roof works in the spring and fall: it gets colder than the air sooner since it is metal and that causes the dew to form!

Lenn Sisson wrote:Here is an interesting design for an air well that I came across today. It includes a wind turbine to pull the air through the system.

I believe that would work beautifully.

R Hasting wrote:

Lenn Sisson wrote:Here is an interesting design for an air well that I came across today. It includes a wind turbine to pull the air through the system.

I believe that would work beautifully.

As long as the ground temp is below the dew point, yes. It's a bit more complicated though, and requires a pump for the water and a fan (although the fan could be a solar chimney or similar). This kind of collector would actually work the best in fog, but not so well in drier climates. This is because water is a greenhouse gas, so fog can block radiative collectors from cooling off, but in drier climates the night sky exposure can be very large so they're much more effective.

I wish the url in that image was still a web page with more information. I live in an area where we often have very foggy nights and I already have a big water storage tank underground from previous owners.

Marc Troyka wrote:

As long as the ground temp is below the dew point, yes. It's a bit more complicated though, and requires a pump for the water and a fan (although the fan could be a solar chimney or similar). This kind of collector would actually work the best in fog, but not so well in drier climates. This is because water is a greenhouse gas, so fog can block radiative collectors from cooling off, but in drier climates the night sky exposure can be very large so they're much more effective.

Clearly, all of this is dependent on there being moisture in the air sufficient to cause condensation at the given temperature. And sometimes that answer would be negative.

And yes it takes a little energy, but you could run this system on a 50 watt solar panel, charging a battery, using a 12V fan, and a $25 12V water pump and a switch. But you are already investing a lot of effort and time into this construction. I think at that point, it might be cheaper to use an old radiator core, the same pump solar panel and fan.

It would all be cheaper is you were on grid though.

I would have to derust my math and chemistry skills to figure out what the amount of water it might generate given a certain flow of air at a certain humidity/altitude and ground temp. I am not motivated enough to do that at this time:-)

Here's the straight poop on using deep soil temperature to condense water out of warm air. Discussion, tables, and handy calculator are included. The author tends to ramble just a bit, but there is plenty of useful stuff in the article. I haven't tried it myself since I live in an area with an annual precipitation of about 70 inches per year.

http://mb-soft.com/public3/water502.html

From Jack's link:



I think this is a great idea. I am tempted to call this a "johnson style air well"

We use these ingenious devices called guzzlers to provide water for wildlife in the west deserts where I grew upwildlife guzzlers

paul wheaton wrote:From Jack's link:

I think this is a great idea. I am tempted to call this a "johnson style air well"

Thats a genius Idea, I would really like to stack that with a solar chimney.