large scale transpiration still

ive googled that a little bit, havent seen anything there or on youtube.
i was watching this video here ( http://www.youtube.com/watch?v=srOQuHxj_dU )
it seems to me like he collected about 1/2 a cup in six hours from a regular sized plastic bag.

so, i got to thinking, if a plastic bag is 3x2 all splayed out, i could make a cube out of that whose sides are all one foot, thus, 1x1x1=1ft cubed volume = 1/2 a cup of water.
then i thought, what if i had a 10x10 vinyl tarp (100 bucks on google, 20 mm thick), i could make a cube out of that whose volume ends up being 55 ft cubed. now, im not very good at math, so i just kinda geustamated. assuming that the WxLxH of this cube is 3.3x5x3.3=55. it isnt, but its close.

then i figured if 1 ft cubed = 1/2 a cup of water, then 55 ft cubed = 27 1/2 cups of water. (based off the video in which he gets roughly 1/2 a cup of water in 6 hours from a normal sized plastic bag.)
13.5 cups of water (27 1/2 cups) is 0.84 gallons of water per six hours.

to make my math more accurate what i usually do is slash my end result in half to compensate for any variables i might be missing like heat variation, amount of leaves in the still, hours of sunlight, etc.

so, thats 0.42 gallons in six hours. now, thats no 4 gallons a day per person in a desert or anything,
but i figure you could rig up a tarp that size around a large branch, use hose clamps to make it air tight, and rig up some kind of hose/spout at the bottom, all for under 150 dollars per rig. so, if you want a gallon of water a day in the desert itll take 300 dollars and a tree.

anyway, just looking for feedback of if this sounds viable or not. better yet, if you know anyone who has tried to make large scale transpiration stills.
and hopefully someone might just make this before me and prove it a good or a bad idea.
one of my main concerns is the health of the tree though, how do you think a tree would be affected by such an attachment. i figure it might actually be good for it since itll be in almost a greenhouse. but it wont have any oxygen to the leaves, or circulated air, itll be pretty stagnant...but it wont be the whole tree either, just a large branch.

anyway, just thinking out loud.

thanks.

Joel Cederburg : You are doing a good job of thinking outside the box, and I couldn't see anything wrong with your math. However,Go back and look
at the video again, Notice how green and abundant the plants are in the background ! Desert plans have evolved and adapted to their environment !
They will transpire 1/3rd or less of what you see here ! You might be able find, with the aid of a good guide a more Temperate Climate tree surviving
over the top of a subterranean desert seep/water trap. but that would be a rare find indeed !

Even in the Environment that you see in the video what you need is hundreds of these bags , not a big tarp ! - Boy, are you over paying for a tarp !

A solar still will let you turn the water from a car radiator, urine or moisture wiped up from a heavy dew, into drinkable water with a piece of plastic
approximately 4' X 4'

'' Outside of That, Mrs Lincoln,'' '' How did you like the play ?" For the good of the Craft ! Be safe, keep warm ! As always, your comments and
questions are solicited and are Welcome! Think like Fire, Flow like Gas. Pyro -maniac Big Al !

that does make alot of sense.
do you think it would still work in a similar climate though? not arizona per se, but well say around telluride colorodo or something like that.
i would imagine the only upside to having this rig in such a situation would be free filtered drinking water that doesnt need to be boiled or anything.

do you have a solar still? are you happy with it? how much water do you get out of it?

Joel Cederberg : While I have made a solar still many times, and taught my grandchildren how to make them, here in the northeast keeping
warm and dry means you have the materials at hand to boil water!

You should be able to grasp the idea behind a solar stills operation in 15 min! Finding the right place to dig the hole will take longer. Do i think
these are good skills to have Yes, yes, and Yes !

For the Good of the Craft ! Big AL!

cool

just a last thought about this, do you think it is plausible to use transpiration in a green house to collect water and reuse? ive read that in a single growing season one corn plant will transpire 200 litres of water.
i dont have a farm, greenhouse, or land really, just dreaming.
but if you could harness the transpiration of a whole garden to water itself, that would be pretty badass i think.

J.C. : Way Cool !It would be possible to build a super efficient air to air heat exchanger to do that. It would be 1/4 - 1/2 the size of your greenhouse but YE$ it could be done !
For the Good Crafts,yr comments Welcome Big AL !

So I've been thinking about this idea again, and I believe I might be on to something. After a couple of rains the cistern fills up, this allows for watering of plants and production of lush green vegetation which then produces a surplus of water which can be used for watering your plants or you. I have included some concept art for visualization purposes and hope the Internet includes it. But yeah, I don't know what an air to air heat exchanger is, but what does it do?and is it necessary with this design? The idea is that after being established it will produce more clean water and biomass than it uses.

Also, one could water this garden with grey water. 100 gallons of transpired grey water would turn into at least 20 gallons of fresh drinking water. And your plants have already been watered.

This made me think of an "air wells" post in the permies homesteading forum (sorry unable to attach it using my phone)

thats really cool.
i geuss i pretty much thought up a huge waterboxx.
has the waterboxx been functionally made or is it a theoretical thing?

thought this was interesting. especially about the maple tree producing 56 gallons of water an hour.

anyway, i might be posting on here too many time in a row, but whatever.
heres what i figured.

a 8x8 greenhouse could hold 36 corn plants, 18 pea plants, and 9 squash plants. all of these plants would be watered with brackish water mixed with greywater, thus they would be in full transpiration mode and produce a total of 2268 gallons of clean water in a season. (corn, 56 gallons per plant per season. peas 13 gallons per plant per season. (source http://www.cropsreview.com/transpiration-in-plants.html) squash 10 gallons per plant per season. (source:if you google how much does a squash transpire, google will say ten times the weight of the plant in water weight. not a clue if they mean fruit included or not. so i just figured id make it ten to round things out.) so. 36 cornx56 gal=1944/18 peax13 gal=234/ 9squashx10 gal=90. 1944+234+90=2268 total gallons transpired in a season from an 8x8 three sisters garden.
plus, i went here ( http://www.braewater.com/calculator ) and calculated how much rainwater an 8x8 roof would collect in deming new mexico (so south its almost old mexico) a year and that is 540 gallons. so, 2268+540 = 2808 gallons of fresh water a year obtained by watering plants with non potable water. a human only needs to drink 200 gallons of water a year (0.528 gallons per day x 365 days = 192.72..//..0.528=eight 8 ounce cups.)

so i geuss what im saying is that if i cut the expected amount of water received by half i get 1404 gallons per year.
if i tripple my fresh water needs per year i get 600. which gives me an excess of 804 gallons of water a year in excess to water stuff with.

so yea. this is all theoretical, but im pretty convinced of it. at least as a good method to turn saline water or grey water back into drinking water. if i had land i would build one. or, if you are a farmer who will let me wwoof your farm and let me build a cistern inside a greenhouse with a rain collection roof for the price of the greenhouse material and daily food and water for me and my wife. (and live west of the Mississippi), i would love to go and build one for you.

Jeol Cederburg :Hie thyself to Instructables.com, with a little bit of digging down through their start-up pages, you can find or from a group that are willing to examine
the possibility of constructing Dew Traps, And Solar stills and Air walls, there is a seemingly large community of "burning man aficionados'' amongst that group, and a
smaller subset of Dune and and Star Wars types who want to pretend they are on Tantoowe (sp)

Seriously, while I personally, living in the Wet North-East have the hardest time wrapping my head around a water shortage that couldn't be handled with Swales on
Contours, I think that there has been little new thought since the semipermeable membrane in the 40s, 50s ! There is much good work to be done here. Also we are
under represented at Instructables.com , and need to make more cross links ! For the Good of the craft ! Comments/questions are solicited and are Welcome BIG AL

regardless of your water situation, do you think this idea is plausible as a method to recycle non potable water into potable water while simultaneously creating food and collecting rainwater?
if not, why? what are the main issues you find to be faulty with this design?
also, i think this could have applications in filtering fluoride and other harmful toxins (fukushima) out of water. (youd have to throw out the plants and close off the rain hole,but youd have non radio active drinking water)
because from what i understand, the plants would hold in any impurities in their bodies and transpire only pure water.
do you think this idea is plausible?
thanks.