why not just distill water using the sun?
 

I see people looking to buy water filters. However, I don't see much mention of the best water filter on this planet: Solar evaporation which removes pretty much all contamination in water (mercury, arsenic, fluoride, chlorine etc). No need to buy expensive filters too.

http://www.unep.or.jp/ietc/Publicati...-8d/F80124.gif

I am thinking of building my custom designed one. Preferably something where I can place it on my roof, connect it to the tap or any other source of water and then run a hose from the unit to a collection tank, either a 5 gallon water jug (for storage) or one of those water coolers. That way you can have unlimited clean drinking water without having to buy expensive filters or bottled water.

Re: why not just distill water using the sun?
 

Solar distillation is a viable alternative with many do it yourself designs and pre made designs available. I think everyone should have this capability in their preps. The only challenge I can see is that if it is your only clean water source, certain environments and certain seasons (winter) may not be conducive for this method. Bx3

Re: why not just distill water using the sun?
 

you can also make the top concave, coming down to a poin in the center like V instead of ^, just not so steep, obviously.

Ive seen it done for survival situations using a hole in the ground and some plastic sheet. Put a rock in the middle so it pulls the sheet down, then put a cup there in the center. Water evaporates, condesnes and trips down the shit into the cup. This is small scale obviously, but same principles.

Re: why not just distill water using the sun?
 

A couple of these Frensel lens on a "still" and you could easily boil enough steam to condensate for water. Just make sure you have it slightly out of focus or you will burn the metal up*


The photo below shows a Fresnel lens boiling water in a frying pan on my driveway. The pan is set well above the focal length, so it won't melt. The size of the spot of light is just a bit smaller than the frying pan, about 6 inches across.

<a href="http://s268.photobucket.com/albums/jj5/4dabopper/?action=view&current=small_solar_furnace.jpg" target="_blank"><img src="http://i268.photobucket.com/albums/jj5/4dabopper/small_solar_furnace.jpg" border="0" alt="Photobucket"></a>



Below is a photo of four U.S. pennies that were placed at the actual focus, a spot of light about the size of the hole in the penny (1/4 inch across).

<a href="http://s268.photobucket.com/albums/jj5/4dabopper/?action=view&current=small_melted_pennies.jpg" target="_blank"><img src="http://i268.photobucket.com/albums/jj5/4dabopper/small_melted_pennies.jpg" border="0" alt="Photobucket"></a>


Three of the pennies were of the old copper alloy type (pre-1982). They contain 95% copper and 5% zinc. The penny on top was the new copper plated zinc type. It is 97.6% zinc (all in the center) and 2.4% copper (all in the plating). Zinc has a lower melting point than brass. Much of the zinc actually burned away, leaving the pitted surface you can see in the photo. The copper plating melted and dissolved into the zinc, making the bright gold colored brass lump that joins the other pennies together. I then moved the focus to the bottom penny, and melted the hole in it. The entire procedure took only three or four seconds.

Re: why not just distill water using the sun?
 

Distilled water is not drinking water. Your body needs certain minerals and often there is no source other than your drinking water. Distilled water is for survival, not your regular supply.

Re: why not just distill water using the sun?
 

The problem with solar distillation is volume. It takes one helluva large area dedicated to this to produce enough water even just for one person. The water bath can't be too large or too deep or you'll never drive the temp up enough to make any difference. That means there has to be some sort of refilling mechanism tied to the water level, and you'd want to pre-heat that to not drop the bath temp. Then you're dependent on the weather too. A string of cloudy days and you're up fecal creek.

It's not exactly a bullet proof stand alone solution, but it would work well in tandem with filtration.

Re: why not just distill water using the sun?
 

In other words, you better have plan B after this.

Re: why not just distill water using the sun?
 

We use to collect rain water all winter, before the new well. But the roof is metal.. took a downspout off, put a 400 gal tank in the back of a truck, and pumped that into a larger tank, don't think it would work with alot of the different roofing materials though.
(some weird chemicals in em)

Re: why not just distill water using the sun?
 

I've heard many different things about that idea. I've heard that distilled water is better because it transports minerals better. Also distilled water has no effect on minerals as long as you have a healthy diet. Often times water is blended with potassium or sodium chloride to help stabilize it. Likewise, you can always add the mineral tablets if its that big of an issue. However, I think its significantly more important to remove all the fluoride, chlorine, arsenic, and mercury from the water. You can always add in the good minerals later.

Been thinking about that, the physics of distillation and I think I have an idea to solve it.

True, which is why I would recommend having backup drinking water. The solar distiller would only be used for drinking or cooking or other tasks where you need very pure water. For showering, toilets etc you would just use regular rain water collection or water well.

Re: why not just distill water using the sun?
 

:beer: So where do you get a lens like that and how much is it.
Very cool.

Re: why not just distill water using the sun?
 

American Science & Surplus sells a 49" x 37" fresnel lens for about $135.

See:

http://www.sciplus.com/category.cfm/subsection/21

Item# 37930

The Mother Of All Fresnel Lenses

It came from either outer space, or a projection TV. Our largest Fresnel lens measures 49-1/8" x 37-1/8" x 1/16" or 1/8" thick, with a 42" focal length. Build your own lighthouse or projection TV, teach optical properties to students, or just turn your 21-inch model into one with a tavern-size picture. Held in the sun, the lens will concentrate rays enough to cook eggs or torch lumber. And, under adult supervision in the parking lot, employees of a certain un-named scientific and surplus purveyor actually melted pennies in seconds. Extremely cool and done strictly, we assure you, to determine the lens's focal length. Do not, we shouldn't have to remind you, store this puppy in direct sunlight. Or let the underage or under-mature sneak it into the sunlight.

Re: why not just distill water using the sun?
 

It wasn't unusual in the 40's and 50's to have two water sources in a house. Drinking and cistern. The cistern would have an automatic valve that when it got too low, would switch it to all city water. The savings for water were significant ... until the cities banned the cisterns after realizing they were loosing precious tax dollars on all that free water. If you look carefully at old photos, you can sometimes see the cistern tank on old houses, mounted just below the gutters. Looks a lot like one of those portable air tanks tow trucks use.

Re: why not just distill water using the sun?
 

Watercone

http://goldismoney.info/forums/showthread.php?t=349358

Re: cheap frensels
 

http://cgi.ebay.com/FRESNEL-LENS-38-...item2a03d4a5bd

And more info on frensels.


http://greenpowerscience.com/LINEARSPOT.html

http://greenpowerscience.com/SHOPFRESNELHOME.html

Re: why not just distill water using the sun?
 

Do you guys actually have a problem with toxic stuff in your water, or are you just hung up on machinery? It would take quite bad pollution to justify all this effort.

Re: why not just distill water using the sun?
 

Living in the San Diego area in the 50's
and Midland Tx. ares in the late 70's.

The water was so bad I would not brush my
teeth with that water!!

It may not be toxic for the body, but for sure
toxic for the taste buds!

Re: why not just distill water using the sun?
 

In a pinch, you could always drink your own pee.

Re: cheap frensels
 

Good links 4dabopper but I have a question. Do you know the difference between the linear fresnel lense and a spot fresnel lense the have for sale? What are the differences and which is better?

Re: why not just distill water using the sun?
 

I'd run mine thru the Berkey, before drinking, tho.

Re: why not just distill water using the sun?
 

There are two basic types of Fresnel lenses, Linear and Spot. Both lenses look identical to the naked eye in terms of the circular Fresnel pattern but a Spot lens will always appear more transparent. Spot lenses produce a very small tight beam at optimal focal length and are generally more powerful size for size. Linear lenses produce a long flat beam ranging from 1 inch high by 3 inches wide up to 1" x 12".
There are the specific acrylics that are UV Stabilized. I have tested several styles for 2+ years.


Linear Fresnel Lens Advantages:
• Less chance of damaging equipment if liquid evaporates
• Long beam can be spread the length of a pipe
• Powers a Steam Engine slower but more safely
Disadvantages:
• More opaque due to physical nature, less light (power) transferred to project
• Cannot be used for melting metals


Spot Fresnel Lens Advantages:
• High power heat transfer (available in Crystal Clear Acrylic perfection cutting)
• Can be set to less of a focal length (ideal for cooking)
• Melts copper and many other materials
• Powers a Sterling Engine and Steam Engine
Disadvantages:
• Instant flame and work hazard
• Equipment damage
• Does not spread over a pipe surface evenly

All depends on what you want to use it for.
the spot is hotter, but smaller area usually around 1/4 of inch.
The linear focus is around 1" by 3" so it will heat a larger surface.

It all depends on what you want to do with it, on which one is better.

Re: why not just distill water using the sun?
 

Solar power runs about 2.6 kilowatts per square yard at the top of the atmosphere. On a good day about 500 watts get down to the ground. That is a peak figure at 65 degrees latitude. That is enough to raise 5.4 pints of water from 70 to 212 F. I didn't figure the extra power to evaporate it. So if your collector is one square yard, your highest possible output is something less than 5 pints per hour at the peak of a good day.

How about a nice green sand filter?

Re: why not just distill water using the sun?
 

#10 Worst water in the country here...

Re: why not just distill water using the sun?
 

"Most people" don't bother with solar distillation because for most locales it is not nearly dependable enough.

Here's a clue: it will work good for you, if you can drive around your neighborhood and see lots of houses with solar PV (electricity) panels on the rooftops.

------

If you lived in a low-altitude (=HOT) desert and had a well (that was itself reliable!) it could work great. But even so, evaporation still won't remove all the stuff you want out; microbes will contaminate the fresh-water side from the dirty-water source. So you still need a microbe filter.


-end-

Re: why not just distill water using the sun?
 

Very nice site plus they have a lot of vintage military gear dirt cheap.


T

Re: why not just distill water using the sun?
 

Or you could pee into your distilled water tank!
:4_1_72:

Re: why not just distill water using the sun?
 

I made a solar still a few years back using a black rubber tub 4 feet in diameter. Covered it with clear plastic and used bungee cords around the tub to hold it in place. A bucket at the center inside and a small rock at the center of the plastic outside to tilt the sheet toward the bucket. I got about 1-1/2 liters of water per day in summer. Just barely enough to survive. A 6 foot diameter hole in the ground covered by plastic and weighted around the edge by topsoil would probably yield a gallon/day.

Re: why not just distill water using the sun?
 

I got some Christmas goodies for the kids there. I also bought a few things for me, of course!:emotions16:

Re: why not just distill water using the sun?
 

Re: why not just distill water using the sun?
 

I used to believe in the anti-distilled water stuff, until I had severe pains in my kidney areas. I couldn't shake it until I discovered distilled water. I think it is the chlorine or the fluoride that gives me problems. Most filters have a hard time with the fluoride.

Re: why not just distill water using the sun?
 

True enough. One can't realize how little sunshine there is until they get a solar panel - at least in the midwest.

Re: why not just distill water using the sun?
 

I don't know how it would affect this concept, but when you start distilling alcohol, the first stuff that comes off is really nasty--I think they call them "aromatics", but I'm not sure.

Raw, or tap, water contains a number of things. Some are EASIER to vaporize than water, others are harder. So, I imagine that distilling would be a three step process, just like distilling alcohol. (1) Distill off the aromatics and discard them. (2) Distill the H2O and keep it, and (3) Discard the remaining slag salts, etc. that didn't distill.

And, isn't commercial distilled water distilled more than once? I think distilling is only a partial process to purify water. It is not 100%, so if something in the feed water is really toxic, a small portion will still survive the 1st distilling.

--Willie