Subject: water utilization model (fwd) AIR WELLS

From: "Lawrence F. London, Jr." <[email-masked]>
Date: Thu, 26 Aug 1999 14:19:10 -0400 (EDT)

---------- Forwarded message ----------
Date: Thu, 26 Aug 1999 09:14:05 -0700
From: William Evans <[email-masked]>
To: [email-masked]
Subject: water utilization model

sounds like "water utilization"should read "efficiency"(same as)...
 so for a given rainfall, one would look at amounts of runoff, amounts
evaporated, stored to aquafier either natural or manmade,amounts of
environmentally benefiecient transducers(trees, plants, etc.), amounts
transpired thru the vegetation/evaporated from the soil,etc, etc...
how one could crunch this all down into a mathematical model is beyond
me....but here's some info i cullled from the net....courtesy of
http://www.tiac.net/users/seeker/creative.html
"""........Another interesting invention that has never been implemented
on a large scale was designed in 1931 by M.
Achille Knapen. He succeeded in condensing and extracting water from
warm air to irrigate fields and vineyards in
southern France with what he called, an "air well" (See U.S. patent no.
1,816,592). Looking like a 40-foot concrete
beehive, it was possible to produce as much as 6,000 gallons of water
daily for every 1,000 square feet of
condensing surface. An airwell can be built on practically any scale,
and the wall materials can be concrete blocks,
bricks or concentric hollow shells filled with sand or earth. A small
airwell 12 feet high and 12 feet across with walls
2 feet thick can supply a generous output of daily water. It can be
fitted with top and bottom air pipes, and a
multitude of condensing plates on the inside. Warm air circulates and
gives up moisture on the cool inside
condensing plates angled downward toward a catch basin at the bottom
were it is collected. Using scrap and local
materials, makeshift air wells could help solve many water problems in
drought ridden areas of the world, especially
in Third World countries. """
 bill evans

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From: "John Abdon" <[email-masked]>
Date: Wed, 01 Sep 1999 06:47:27 PDT

From: [email-masked]
Reply-To: "permaculture" <[email-masked]>
To: "permaculture" <[email-masked]>
Subject: Re:  water utilization model (fwd) AIR WELLS
Date: Thu, 26 Aug 1999 16:43:52 EDT

... it was possible to produce as much as 6,000 gallons of water
daily for every 1,000 square feet of
condensing surface ...

That works out to just over 1/2 ounce of water per minute per square foot of 
condensing surface. Remembering that heat is released as water vapor 
condenses into droplets, a glance at a mechanical engineering 'steam chart' 
reveals why this idea for recovering water from the atmosphere has not been 
demonstrated to date: the released thermal energy quickly heats up the 
condenser and the temperature difference between the air and the condenser 
approaches zero, at which point no condensation will occur.

  `\\\||/    johnAbdon  [email-masked]
    (@@)     Kirkland, Washington, USA
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From: Jack Rowe <[email-masked]>
Date: Thu, 2 Sep 1999 00:40:27 -0400

Good point, Christopher. I noticed the math on this one, too, and believe
what might have been meant was that 6,000 gal/day can be had from a
condenser with 1,000 square-foot FOOTPRINT, about a 32-foot-square
building. The actual condensation area would have been MUCH larger. 6
gal/day from one square foot of actual condensation surface would cover
that square foot with ~9 inches of water. 

Jack

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From: [email-masked]
Date: Thu, 2 Sep 1999 17:25:38 EDT

In a message dated 9/2/99 4:41:32 AM, you wrote:

<<Good point, Christopher. I noticed the math on this one, too, and believe

Jack>>

actually, someone else posted the math, I can't take credit for it. I just 
reposted the whole thing as a request for more info/experience, as it seemed 
a little out of the realm of the physically possible. where I am in northern 
california there is a tremendous amount of accumulated dew on anything metal 
or plastic, but no where near what this is suggesting. haven't contacted the 
author yet though I intend to. will report back what I find out.
hope all are well,
christopher peck
philo, california USA

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