Very Quick question on passive solar water heater....

Hi - Someone here will have the quick answer for me I'm sure... I'm looking into building a passive solar hot water heater on top of a small house in the US Virgin Islands... So far, I'm leaning toward using a 200' coil of 1" or 2" plastic pipe as the main collector and from there into a tank. I'm VERY new to this... Please tell me why - do they run the cold water inlet into the bottom of the storage tank and then into the collector before returning it to the tank?.... Why wouldn't you want it to just go straight to the collector??... Thanks in advance.

If you could post two simple diagrams that would reduce/eliminate some of the uncertainty about your question.

I can make some general comments until then.

Passive means no motors, pumps, fans, electricity, or controls. Is that what you mean?


Some solar water heaters use the temperature and density differences to circulate the water between the collector and the storage tank. This is called thermosyphoning. In order for this to work, the storage tank has to be physically higher than the collector, and the pipes have to be connected in a very specific way to get your free-no effort circulation. The top (hot) outlet of the collector must connect to the top (hot) inlet of the storage tank, and the bottom (cold) inlet to the collector must connect to the bottom (colder) outlet of the storage tank.

There's a nice diagram a few pages down here :

http://www.volker-quaschning.de/articles/fundamentals4/index_e.php


Looking forward to your reply to get your plumbing sorted out.

Thanks very much for responding. My question relates to "figure 3" in the article you shared. I just don't understand why the cold water supply wouldn't go straight to the collector (bypassing storage tank) - ? Intuitively, it just seems like you're making hot water and dumping it back in to mix with cold water in the supply tank..... ??

Charles Heller : Let me take a shot at this, because this used to bother me until My Wife and I made some observations using back pack showers ! The answer
is valid, it may not be the most correct answer !

With any collection system but especially any involving thermo-syphoning the temperature difference between the cold water supply ( here labeled Advance/cold)
and the Hot Water return pipes will cause a thermocline or stacking of temperature gradients in the storage tank, The system supply tank being plumbed into
Your Storage tank helps create eddy currents and turbulence to cause mixing in the tank ! This does not subtract any heat energy from the tank, merely reduces
the temperature that your water is stored at. With a lower heat gradient between the incoming water and the warm water already in the tank more mixing
happens!

There is also a small aid to mixing of the thermal gradients from drawing cold water off of the bottom of the tank !

Think of an 8' deep swimming pool when you First set it up in the spring ! Just floating there holding onto the side of the pool you let your feet float down
towards the bottom of the pool and notice that the bottom of the pool is much colder that the surface layer.

Now two things can happen, during the day you can have hot bright sunny days and warm nights and the pools surface temperature climbs during the day,
but then radiates much of that heat away as the night time temps cool and you gain little or nothing !

If however, You get a couple of days with high winds and only some clouds the mixing of the deeper waters means that less heat is radiated off at night
and the next days solar gains will not be stratified at the bottom of the tank !

So back to that Solar Shower Backpacking bladder ! Here the black container with or without an additional sheet of clear plastic over top will with good sun
exposure quickly heat up and stratify the topmost layer radiating of substantially most of the heat away due to the laws of physics that deals with a perfect
radiating body !

A quick agitation of the contents mixes all the water ( at a lower temp) and allows more heat energy to be stored without radiating off most of it !

If you have any type of space heater that delivers radiant heat you can do an experiment with at least two clear plastic !/2 gallon milk jugs, the kind that
are taller than wide, For this experiment there is no need to paint any thing black , just label the one that periodically gets 'Shaken and not stirred'

The one with the most frequent agitation will not stratify and will retain the most heat energy, and the most heat *

Failure to have a system plumbed like this will result in getting very hot water from the storage tank followed very quickly with a more tepid Flow, this
is not a product the average housewife will 'learn to love' !

With several temperature probes monitoring the temperatures at various levels in the tank, most domestic wall mounted remote sending Thermostats,
( if yours is less than 10 years old then probably thats what you have) Could open and close a set of valves to further reduce/eliminate any Thermocline
or stratification

You should be aware that even with a good Solar system that collects and stores massive amounts of heat energy as hot water, Before it can be used as
your domestic hot water supply, it will hang outing a holding tank that usually has a back-up heater element and mixing valves to be able to deliver you
a safe delivery of water at a uniform temperature to make sure the final product is well received by the final user

*Finally, I did not mention that the holding tank located well above your solar collectors and all the return lines would be heavily insulated, hopefully to make
the Solar shower bag analogy seem more meaningful and germane !

For the Good of the Crafts Big AL !

Dang! - I love the passion and knowledge found in online forums! (subarus, VW bugs, now solar energy)
I think if I read your response three times (and I will - at least) I will almost understand it. I have about half of it right now... It's like listening to my two sons (in college) talk about physics - blows my mind.
So - I'm obviously in the right place! Could you (or anyone) help me out with this then...? Here's the deal: My sister has a very small and rudimentary house in the US Virgin Islands. It's a poured concrete/re-bar structure - rural setting. They get water from a shared well a good ways away (hundreds of yards) - pressure is "okay". The "home" has a kitchen sink, toilet, shower, basin, and washing machine. It's nothing "awesome" but it's a free place to stay in the tropics when I go for 2 or 3 weeks to escape the Minnesota winter!

I'm the "handy" guy. My son and I are going down there in March and she'd like us to look into adding a solar hot water supply... There's no gas and electric supply is minimal, as is money. So, I'm looking for a design that is relatively easy, cheap and effective. I believe we're talking about a roof installation (though I could be swayed otherwise)... There will be no "back-up" water heater. I think it might be cool to also add a "cistern" of sorts to the system also - nothing huge at all - just some amount of rain water storage that could be used as a back-up when the well shuts down for a day or an afternoon...

This basic design intrigues me... https://www.youtube.com/watch?v=AVjKnq4O7Pk

- thoughts???
I'm also curious to know why, in this one, the storage tank is covered in reflective material rather than painted black...??

Thanks very much!!
Chuck

Charles Heller : O.K., Just remember you asked for an answer! (the caption under the 2nd picture on the right explains it better than the whole rest of the article!

Emissivity and thermo-god- damnics

for this reason the coil should be covered with some kind of clear plastic membrane, but as this is India a little Thermal heat loss is no big deal, the system should
have a boiler grade pressure and temperature pop off valve vented to at a safe, location, or better yet a vented system that can not be pressurized, right now I can
not visualize the second iteration.

For the good of the Crafts! Think like fire, Flow like Gas! Don't be a marshmallow! As always comments and questions are solicited,and Welcome, pyro-logically Big AL

Charles H. : You and your simple Questions, I actually only gave 1/2 an answer to your last question and I had to chase for the best way to present the last 1/2
The link below will talk about the dangers of heating water with any solid fuel and the need for the system to be unpressurized, no Boom - Squish !

Then a question is asked about another type of system in a separate thread It is Very important that you take the time to read my 3rd comment about separating
the water stored within the holding tank from the water actually used for domestic water consumption ! This DEFINITELY Includes Showers !


Wood fired hot tub

For the Good of the crafts ! Hope this helps and is timely Be safe ! Big AL

Let's do a mental exercise to understand -why- therosyphoning works.

Imagine you have a simple square loop of copper pipe filled with water. For thermosyphoning to work, it has to have a complete loop.

If the water in the entire loop is the same temperature, the water will not move.

But if you put a torch (or a solar heater box) on thebottom corner of the left vertical pipe, that water will expand a bit. AHAH! The density changes. Now the water in the left vertical pipe is less dense (lighter sort of) than the water in the right vertical pipe. Since they are connected, the colder dense water in the right pipe will go down, and hotter "lighter" water in the left pipe will go up. It is that density difference that makes thermosyphoning work. In this example, the colder right pipe is your storage container.

If you don't have thermosyphoning (or a pump and thermostats, etc), the water in the very hot collector box never moves, it can overheat, flash to steam, blow up and literally scald/burn somebody to the point where they could die.

That's why you must have circulation between the potentially very hot collector box, and the storage container. That either means pumps and electricity and thermostats, or arranging the storage box higher than the very hot collector box to allow for thermosyphon to work.

The very hot collector box will get far hotter than ambient air temperature. Let's just pick a number and say it gets to be 185F. Then that hot water flows into the storage tank, which is cooler, but still well above ambient. Let's say the storage tank is 125F. At that temperature, the storage box will lose heat to the air. That's why you would want an insulated storage tank, not a black bare tank. It's job is not to collect the heat, it is to store the heat.

hth

troy

Well shoot - that sounds a little discouraging!... I grasp the reason the storage tank isn't black (that's good for me!) and it sounds like "vented" is the way to go. I'd like to avoid things exploding also... (How do you vent it without it becoming a "continuous drain"?...

But beyond that... It sounds like I need to "separate the water in the storage tank from the water to be used for showers etc." and I'm not quite following that. It seems like you're saying that best case scenario would be an electric hot water heater inside the house that would accept the water from the storage tank and be kept at 150 degrees or above...?

And that I could do it without that but I'd still need to ensure that it's kept at 150 or above - or die of some tropical disease - right? Is that a realistic thing to expect? or should I just resign myself to needing to find some sort of water heater for the 2nd tank? ------------------ and IF I were to go without an indoor heater are you saying I would still need to have a 2nd tank? - Why?

Thanks!! (I'm sorry this isn't all as easy as I thought it was - but I VERY much appreciate the information!)

Chuck

Charles Heller wrote:Well shoot it sounds like "vented" is the way to go. How do you vent it without it becoming a "continuous drain"?…

O. K., look closely at this, if I have loaded this right there is 18 minutes you don't have to watch ! http://youtu.be/oiwnYqcRLZw?t=16m18s

But beyond that... It sounds like I need to "separate the water in the storage tank from the water to be used for showers etc."

O. K., Here is another forum thread dealing with separation of the two water streams, you want to scroll down to find the thread extension posted by Kirk
Mobert. and then scroll down some more until the 13th and 14th pictures that shows how Your holding tank can serve as a reservoir that your copper coil
can then set in . This coil is supplied with your domestic hot water and the domestic hot water flowing through the coil picks up heat energy from the holding
tank, It never gets a chance to set at a temperature where it can brew up a deadly batch of legionaries disease and it is a separated water stream and can
not become contaminated !

https://permies.com/t/39243/rocket-stoves/Rocket-Mass-Heater-Workshop-emphasis

It seems like you're saying that best case scenario would be an electric hot water heater inside the house that would accept the water from the
storage tank and be kept at 150 degrees or above...?

Way back at the beginning I mentioned that Mrs. American housewife would not be happy with water that started out hot but cooled down rapidly, most
commercial systems use a electric or gas hot water heater to give Mrs. A Housewife what see wants , the water in this tank is held above 150ºF and is safe,
inorder not the accidentally scald the young, the weak, the elderly or the immune compromised, that hot water gets mixed by a mixing valve to deliver a safe
clean uncontaminated hot water supply at a safer 140ºF - this water was just 150 degrees a moment ago, and has no colonies of nasty bacteria !

While you are on vacation you can just ruff it, but the safest thing is to flow clean water through the first tank, it supplies heated makeup water to the 2nd tank,
often the water supplied to the second tank will be above 150ºF and that 2nd heater will not need to run to make a safe 150ºF, water supply source, but It can
if needed-

O.K., I needto test these links and I think we are good to go ! Big AL

Charles These links are tested and good! Just one more so that you understand it is not just some tropical disease you need to worry about .
Though again -the same people that need to be protected are the Young, the old, the weak, and the immune Challenged These people need the
water in their water heater to be at least 150ºF, but these are the very same people who are most likely to sustain scald injuries if the water
Temperature at the facet of a sink, tub, or shower is above 140ºF ! So just one more Link

http://en.wikipedia.org/wiki/Legionnaires%27_disease

This link, and the two above have been checked and are all good

For the Crafts ! Big AL

Charles : Actually I am a little surprised that No one found any problems in the way I described things, there are more than one correct way to do many of these
hook-ups!

In Trying to look up at the ceiling and visualize the systems talked about, I may have misspoken myself somewhere though I have just re-re-read everything and
did a little polishing, I guess it will stand until someone shows up to suss it out.

This link is to a .com site that has been helping people for 40+ years and deal with people, the vast majority of which don't understand the subject well enough to
ask reasoned questions like you!


http://www.builditsolar.com

Give me a couple of seconds to test this link! Its good!

http://www.builditsolar.com

For the Good of the Crafts ! Big AL

Thank you! I am reading it all and I will be back with more "simple questions"!

Thanks - I will be back... holidays and all....

Charles Heller wrote:Thanks - I will be back... holidays and all....

Okay - Holidays are over...

I'm leaning toward something like this: http://www.builditsolar.com/Projects/WaterHeating/CostaRicaThermosyphon/CostaRicaThermosyphon.pdf

- unpressurized - float valve - plastic tank of some sort - PEX pipe.... There is no normal hot water heater in the house. What I build will only supply a shower and a sink.

I'm not to worried about water that's "too hot" - only used by adults and there will be mixing valves at each spigot.

USVI is pretty much 70-90 degrees year-round. From what I read I should have no problem keeping it above 150 degrees, but bacteria makes me paranoid...

So.... the storage tank will have a "temp gradient" - right? What do you expect that range would be from bottom to top?... What is the location of the hot water outlet pipe? - top 3rd of tank - maybe?

Should I install a temperature sensor and gauge somewhere?

Charles H. : I think you have a handle on it now, the tank needs to be insulated from heat loss, There will probably be a slight drop in pressures as valves are left
openso the force of your shower will probably drop a little as will the temps, but on a sunny day your recovery will be quick !

I would avoid trying to make your system 'just a little bigger' as with a thermo syphon system there will be heat loses and your increased size may not do as well
for you as a smaller system with fewer and smaller heat sinks to lose heat energy !

As a mater of being practical, a short hose to be able to rinse sand and salt of of food and sandy feet will be something you will thank yourself for a 100 times a trip!

For the Good of the Craft ! Big AL

Charles Heller wrote:

Charles Heller wrote:Thanks - I will be back... holidays and all....

Okay - Holidays are over...

I'm leaning toward something like this: http://www.builditsolar.com/Projects/WaterHeating/CostaRicaThermosyphon/CostaRicaThermosyphon.pdf

- unpressurized - float valve - plastic tank of some sort - PEX pipe.... There is no normal hot water heater in the house. What I build will only supply a shower and a sink.

I'm not to worried about water that's "too hot" - only used by adults and there will be mixing valves at each spigot.

USVI is pretty much 70-90 degrees year-round. From what I read I should have no problem keeping it above 150 degrees, but bacteria makes me paranoid...

So.... the storage tank will have a "temp gradient" - right? What do you expect that range would be from bottom to top?... What is the location of the hot water outlet pipe? - top 3rd of tank - maybe?

Should I install a temperature sensor and gauge somewhere?

Hi Charles,
So you live in the Virgin Islands? A thermometer is useful but not necessary, with temps like you have, you can leave off insulation on at least part of the plumbing to feel the temp of the pipes. I see they didn't insulate the pipes at all, but consider that sunlight photodegrades all types of plastic. Even a coat of paint will halt this process. I would be concerned about various growths in the tank, just keep an eye on it at first to see what happens. To enhance thermosyphoning, the bottom of the tank should be above the top of the collector, and flow resistance should be reduced by minimizing elbows and using larger diameter pipe. The hot water connection should be at the top water level, and the cold into the tank should be at the bottom. Not sure what gauge you are referring to. Sundug

http://www.builditsolar.com/Projects/SolarHomes/Doug/DougsProjects.htm
 
youtube.com/c/DougKalmer

What I'm not quite clear on is where the "hot water out" pipe goes... I get that the hot stuff will be on the "top" - but, as a non-pressurized set-up, I will have to pick a point on the side of the tank - right? -- So, essentially, if I used a 20 gal drum and put the outlet a third of the way down the side, I might have 6 or 7 gallons of "really hot" water before the temp starts decreasing much - right?

And it just seems like if "stuff" grows below 150 degrees, I shouldn't be using it if the temp in the tank goes below that - ? At what point in the tank would you measure the temp of the water?

Thanks! - You guys are GOOD!

(and I like the foot-rinsing hose!!)

You could put a weekly or daily dose of bleach in there if you're nervous.

Ten bucks worth of shock-n-swim would last you for years:

http://www.amazon.com/Arch-Chemical-51109-Shock-1-Pound/dp/B000JWCB06



hth,

troy

Charles Heller wrote:What I'm not quite clear on is where the "hot water out" pipe goes... I get that the hot stuff will be on the "top" - but, as a non-pressurized set-up, I will have to pick a point on the side of the tank - right? -- So, essentially, if I used a 20 gal drum and put the outlet a third of the way down the side, I might have 6 or 7 gallons of "really hot" water before the temp starts decreasing much - right?

And it just seems like if "stuff" grows below 150 degrees, I shouldn't be using it if the temp in the tank goes below that - ? At what point in the tank would you measure the temp of the water?

Thanks! - You guys are GOOD!

(and I like the foot-rinsing hose!!)

The hot out should be as high as possible on the tank for the hottest water. YMMV, but my solar hot water tank is often below 150*F, and have had no problems in 24 years. It is closed and pressurized, but only to about 15lbs, as my water is spring fed from an open spring tank. Sundug

http://www.builditsolar.com/Projects/WaterHeating/DougsSolarWater.htm

Charles Heller : I agree with Doug you would want to take your discharge from the very top of your barrel where it is hottest !

Doug Kalmer : Thanks for joining the discussion, We have been taking about the temperatures where Legionnaires Disease is likely to propagate itself

Legionnaires Disease is a large potential problem in water storage, especially open systems where wind and birds can be vectors !

At ground water temps even in the tropics Legionnaires is extremely rare, however if the tank is allowed to remain full for several days, and is not kept
Above an internal Temperature of at least 150ºF Legionnaires pathogens can rapidly multiply into a soup, when the contaminated water is flowed through
a shower head there is always a certain % of the Spray that is aerosolized, this creates a pathway for inhalation of the Germs, and is the most common
pathway of infection for Legionnaires, this will present initially with flu like symptoms before quickly becoming a pneumonia !

So- We have Two choices, carefully draining down the system immediately after use, or placing a 1/2'' - 3/4'' copper or stainless steel coil inside the
holding tank as a heat exchanger, never allowing the holding tanks possibly contaminated water with the shower supply water.

Ether system will prevent an exposure to warm water that tropical weather conditions has held high enough to breed a Legionnaires Disease Culture inside
the holding tank but has not been held above 150ºF!

Being dependent on the temperature gradient for safety is very chancy, and what about those showers late at nite just to wash the days sticky off before
laying on clean sheets, If the system has been drained down, there is no soup of legionaries disease and you can have a cold shower, with a coil system in
a tank you can divert your water flow without going through the coils, cold shower-ish or take a shower in tepid water without fear of inhaling Germs from
a lab-culture several days in the making !

I will need to hunt up a couple of valves to positively prevent the pressurization of this system and come back to a new thread extension ! Big AL !

Chlorine kills legionella effectively.

And if you have decent contact time, 130F also kills it.


troy

so - chlorine dosing seems an option -- ?

--- The whole internal coil thing seems such a huge add-on...? IF I went that route, would one ever use PEX for that, rather than copper? Is it efficient enough? It seems you'd only have 2 or 3 gallons of hot water available at any one time - ? And the hot water that's used to heat the coil... would you just plumb that to the sinks and never worry about "disease" since it's not aerodized?....

What temps might you "expect" my system to fluctuate between in an average day?

and - okay.. "hot water out" pipe at "highest point" - so, you would definitely set it up so as to be more or less dependent upon "continuous supply flow" to force water up and out?... It seems like one might put the out pipe "a few gallons" down to provide one nice hot shower regardless of available pressure... ? - not worth the tweak?

AND.... so the guy in the write up I used above used a 20 gallon tank... Is that "plenty"? - and easier to keep hot? How many 5 minute showers might that be?

Thanks.

A low flow showerhead makes a lot of sense in this scenario. A typical one will use 1.25 gallons per minute (which is not all hot, you will mix with some cold) Of course, they depend on have a certain amount of pressure...worth looking into.

How much pressure do you think you will have?


troy

- O.K., today I am getting some of my own medicine back, It is really easy to skim over the various Thread Extensions , and be sure you have grasped the heart
of the issue being discussed !

In This case we are talking about an outdoor shower point for limited use only, in season and mostly for use following a trip into town or coming back from the beach

A homemade Domestic hot water coil, or even one 2nd hand from a hot water heater will be a simpler system than any chlorine injection system, and then we need
both contact time and agitation in a system designed to run cheaply without Electrical energy inputs ! Introducing the chorine within the holding tank, barrel through
which the shower water flows inside the coil would certainly be a belt and suspenders way of nearly eliminating contamination !

Given enough contact time, 130ºF And U-V Exposure, will certainly kill most waterborne pathogens.

Chorine will break down into several different metabolites in the presence of organic materials, and various metals, most of the breakdown products are rendered
ineffective ! And now we are getting into flocculation, settling, and filters for an outdoor shower point.

I set of to find some simple D.I.Y. positive vents for the system, This is a link to a separate Thread, Thread Extension on an other topic, please see my Links
near the bottom, January 4th 2014 :


https://permies.com/t/42768/rocket-stoves/heating-coil-pipe-heat-water

For the Good of the crafts ! Big AL

The coil will do it's job forever with no daily or weekly chores, that's for sure.

You might be surprised the performance you can get out of a black roll of plastic pipe or a black drum storage tank used as a batch heater.

My head is starting to spin again...

Back to basics here for a minute to give you guys a clear picture...

St. Croix, USVI... 70 to 90 degrees, virtually year round...

This "house" is used by one guy for 6 or 7 mos. per year. He is joined by my sister for 2 or 3 months. They are joined by two to four guests for 2 weeks to a month or so... The H2O supply is from a shared well over a hundred yards away. The water gets there via a garden hose laying on the ground. The house is "plumbed" with a shower, a toilet, a bathroom sink, a washing machine for clothes and a kitchen sink - all with just the cold water... - poured concrete/rebar construction with a flat concrete roof...

So we aint talking "The Ritz" here but (for me) it's a very nice (and cheap) way to visit the islands and I'd like to be able to take a warm/hot shower every couple of days while I'm there. If it's "easy" to add hot water supply to the sinks and the washing machine at the same time, great! - I'd like to do that. But the shower is the main thing.

I'm thinking $300 - $500 max...

What sort of system would you suggest?

One "new" question that's popped into my head... Do you suppose the water sitting in that 100+ yard hose is susceptible to "pathogens"? What are the implications of that?... ----- Related, I'm not quite sure why a system with a "coil" would be any less likely to breed bacteria etc.? Isn't the coil really just another container...??

Similarly, while the non pressurized system I proposed might be "open" by definition - once it's built I'd have a "top" on it (with a vent). So... is it just exposure to heat with "air" that's the difference? I gotta believe there's air in the hose....?

-- See how I'm getting lost here...

What do you think? -- style? - capacity? - fixtures? - safety? - cost?

Thanks once again - VERY much....

Chuck H. : I needed to be reminded about the garden hose that carries the water to every where else, We do not have to worry about the water that goes
through the garden hose and fills the toilet , nor do we need to worry about the water that goes to the washer, so as you go through your Adult Daily living
Tasks you will flush out the garden hose and this will prevent the accumulation of a Soup of Legionnaires and other germs, it is the long contact time where
the water is stagnate and smells so (aerolyzed ) !

Flushing the hot water heater once or more per day will keep that water clean as you have just restarted the clock as it were, yes certainly you could use
the water from the holding tank for any number of sinks, there will be a vast difference in the operating temperature due to time of day and the amount of
insulation on your tank, But may hay while the sun shines I think you could count on at least one hot shower an hour for 10 -12 hours in a day, probably
some of them would need a mixing valve to cool them down at the start, better a nice hot shower that stays hot than a hot hot one that cools towards the
end and makes you feel cheated !
For the Craft ! Big AL !

Okay..... Now, it seems you are suggesting I stick with the design I suggested - One 20gal (?) batch tank and flush it daily. So is the implication that legionaires takes longer than 24 hours to breed?

IF - I were to go with a design with a coil... How does this sound? What if I built the system above and plumbed the sinks and washer to it - but included a coil inside the batch tank that just fed the shower....? AND - what if the water from the coil then flowed into a seperate "closed" (?) tank so as to have more volume available for shower...?

--- Thoughts on tank sizes in any of these scenarios?

Thanks

Just for completeness, there is the extremely low tech, extremely inexpensive, no moving parts camping shower bag:


http://www.walmart.com/ip/COLEMAN-SHOWER-CAMP-5GAL/13848644



3 or 4 or those would add a surprising amount of civility to showering for well under fifty bucks.

Charles Heller wrote:Okay..... Now, it seems you are suggesting I stick with the design I suggested - One 20gal (?) batch tank and flush it daily. So is the implication that legionaires takes longer than 24 hours to breed?

IF - I were to go with a design with a coil... How does this sound? What if I built the system above and plumbed the sinks and washer to it - but included a coil inside the batch tank that just fed the shower....? AND - what if the water from the coil then flowed into a seperate "closed" (?) tank so as to have more volume available for shower...?

--- Thoughts on tank sizes in any of these scenarios?

Thanks

If using PEX instead of copper, it takes about 3 times as much to get the same ability to heat the water in the coil. The coil should be placed as high as possible in the tank, and if a large enuf length and diameter PEX is used, like 1", it will contain enuf heated water for a decent shower, meaning you could skip the second tank, using the coil as storage. . Allow some time before the next shower for the water in the coil to heat. Check out- http://www.builditsolar.com/Experimental/PEXColDHW/HXPerformance2.htm
Also, There should be no "heat traps" in the collector to tank loop. A heat trap is where the line goes up and back down between the tank and collector. If there are any valves in the loop, they need to be full flow, as in ball or gate type. My wife and I have both taken a decent shower from one filling of a 5 gallon solar shower bag. Sundug

Chuck Heller : As a minimum you are building an Air castle with so many interconnected valves and possible self syphoning situations you are going to end up
with a check list to follow! Is this valve open or closed, did I drain this part of the system -

Yes, modern germ theory says that you have to be exposed to X number of germs to become a potential host, flushing your system and draining it down, say
into your toilet or washing machine or used for garden watering would be acceptable, on days when the system has been well used even washing vegetables
and boiling, The Idea is making the system simple, I seems like it is getting more complex. as a second holding tank and its weight suspended above your
shower and of course this adds an insulation requirement.

We have not discussed How you are going to get the water into your holding tanks as thermo syphoning will only circulate that water, not lift it up against gravity

I do think it is more than possible to drain your system down and recharge it every day, Perhaps a couple of times a week you could drain the tank down and
let one end with a removable insulation panel bake in the sun and fry any little beasties that wanted to hide in your system.

Troy I did talk about the camping style black plastic shower bags in my first post, using their characteristics and willing ness to stratify or form gradients with
different water temps in the 6th paragraph or so, if you can fill them and then set them on a dark insulated surface and drape a covering sheet of clear plastic
including an air gap, and wet yourself then only use the water for a fist and second rinse you can use one bag for daily showers for 2 (friendly people) !

One bag a person is luxury, To bags per person is a heavenly indulgence !

I still have a shower bag that is at least 10 years old and used on the Appalachian Trail I have replaced the bag once and the shower hose twice !

Fir the good of the Craft ! Big AL

Haha! Have you ever had anyone ask a more thorough "Very Quick Question" ??!!

It's coming into focus now though (I think). "Keep it simple." A few more questions though.

1. "Concept".... What if I determined that the entire system held say 25 gallons... Could I use a "flow meter" of some sort and just make sure we use at least 25 gallons in each 24 hour period? Then we wouldn't have to "empty" it every day - right?

2. Using a collector like the one in my plan - can I assume that "all" the water is actually "moving" through the system (in essence, flushing itself) and not just heat transfer taking place?

3. - Reading a little more on PEX, it seems it's not great for a collector as it doesn't like UV. I suppose copper would get pretty pricey(?) The guy in Costa Rica used PVC - is that the next best option?

4. - Tanks... If I'm gonna go out and find some sort of plastic or poly "barrel" -- What should I be looking for?

5. I DO appreciate the "camping bag" thoughts also... -- There's another spot we could use those...

Thanks!!

Charles Heller : O.K. remember that you brought up the subject of possible contamination in Your supply hose, ideal temps for just one of the possible pathogens you
could encounter Legionnaires is 95º F and higher .

It is highly possible that you can find an abandoned building ( here in the states ) with a flow meter that belongs to some municipality that is never going to sent a
water district employee to recover, testing your unit before you leave home will give you an idea of its accuracy and a conversion formula if needed ! This could
also be a source of a domestic water only copper coil for your retro-fit inside a barrel ! Or you could hope to find a heating contractor who has replaced a damaged/
leaking boiler and saved the domestic coil waiting for you to show up and get a deal on it !

Any time you see the words thermo syphoning think recirculating and not flushing the Costa Rica build is thermo syphoning and to drain down the system even every
other day would be a problem,

I would expect with a non pressurized system the whole systems longevity would be enhanced by the fact that with the system "wet" it can never get warmer than
212ºF., but drained the temperatures could rapidly get higher still !

Eventually this system will probably fail do to U-V exposure though covering everything with latex paint cheap or insulation not as cheap would probably double the
life expectancy

Barrels vs drums : Barrels generally hold liquids, drums hold - well everything else, 30 gallon drums are scarce on the ground but can be found if you look for them
Often you can find a 55 gallon Drum with a mechanical clamp that holds a removable top lid or cover, and has a very thick food grade epoxy coating !

The best place to find drums is Arts and Crafts Businesses like candle makers, or soap makers ! A good start is actually talking to someone who knows
their inventory and knows the difference between a barrel and a drum ! AND you may have to arm wrestle someone who wants a couple of drums for their next
Rocket Mass Heater RMH project ! See link below :

http://www.freundcontainer.com/images/500/FM402_stainlessopendrums.jpgBusinesseshttp:
http://www.hiwtc.com/photo/products/29/06/44/64400.jpg


I found this by typing in a Google Search for ''Steel Drums for Sale Pictures'', and then clicking on a likely picture, you can do the same and expand your search
to plastic drums !

Then go on a local hunt when you have an idea what you are looking for, Try Craigslist.com and Freecycle.com (?!)

A friend took the agitator and the inside perforated basket out of a washing machine and set that 'holding tank' inside a 2nd story room that was higher than the
shed roof his collector was on! The shower was still outdoors and above his garden !

Have you looked yet to see what you can find at 'Mother Earth News' especially the available reprints?

BOY are you getting an education ! have you figured out how you can use gravity to fill this system ? For the Crafts ! Big AL

Okay................ - approaching suicidal here...
You are either toying with me or you don't appreciate how dense I am.

Please slow your brain down and try to line up "the answers" for me.... ?

It's obvious you are a trove of information but my head's still spinning.

Maybe I'll just end up installing 4 shower bags on a pully system - so we don't have to climb on to the roof to fill them - and run the hoses through the wall.... but it still seems like there has to be a more elegant answer!............. No?...................

I've outlined the basics - cost - simplicity - safety - are all major concerns.

I'm here now... I thought the garden hose "supply" was "no prob." but I re-read what you said about that. So, it would seem the "only" answer to the safety concerns is to ensure that all the water reaches 140-150 degrees before use. (?) Once it reaches that temp, if it's used or drained within 24 hours, we're good - right?

BTW - as far as filling this system goes, I've just been assuming we'd run a hose up to the roof... (?)

A coil system wouldn't solve anything for me since we have to assume the supply is contaminated - right? A coil would just make it that less likely that we'd get it up to temp. to kill the bugs.

This may be a "crazy" proposition but that's how my mind works... Are there reasonably priced "temp. sensitive valves" to be had? What if the hose was connected to a "collector" - say similar to the one in Costa Rica - but that there was no "recirculating"... the water would flow into the collector and not be allowed out till it reached 150 degrees -- am I talking Star Wars?....

Short of bleach or UV - I've got to get it to 150 - right? How do I ensure that?

The only other thing that caught my eye was the post above that talked about how copper kills the bugs........ but.... I'm assuming if that were really true there'd never be a worry - right? Just run the final product through 20 feet of copper pipe...?? It also had me wondering if I could buy a copper plate and toss it in the batch tank...? How about a bunch of those copper bracelets that are supposed to take care of your aches and pains...?

Help!!
thanks..........

Chuck : All your problems Would be solved if you could hold your water temp at or above 140ºF constantly, Dry insulation around your holding tank would help
greatly, a combination of hot humid weather frequent storms and clouds would be apt to hold your temperatures down below that point!

The smaller the holding tank, or collector the more likely you will be able to do this.

1a)Winter weather slightly cool at night drain the tank into a ground level holding tank that can re-radiate heat to extend the comfort range of a sunroom/porch
/deck

1b)During hot weather when cooler nights are something to look forward to, the water can be drained in the morning, this is saved in a ground level holding tank
for washing patio,and reverted to a garden space or the could be allowed to drain onto the roof lowering the buildings night time temperature !

2) The Contaminated hose, measure the volume and flush that everyday, it can be part of a regular schedule, A few early morning trips to the bathroom, and the
hose's contents are flushed, any extra water could be held in a washing machine !

3) fill up the system in the A.M. no contaminated water in the hose or the holding tank, while I would still like to have a separate coil within the barrel for safety
thissolves most of your problems and I have a trick up my sleeve ! (for a later Thread extension !) best Big AL.

Okay.......................................................
1. Flush the hose in AM (toilet - washing machine - garden)
2. Take a tepid shower or two...
3. Drain the system (garden barrel)
4. Refill system.
5. Take a few comfortable evening showers
6. Rinse & Repeat

- right?

So.... Are we now talking just a "regular" batch system? A tank in a glazed enclosure? - No reason for a "collector" - right?

Chuck

Charles Heller : Start looking into bread box batch water heaters, When the water heater is inclosed in an insulated box and painted black you can glaze
one or two sides and when you drop open the door like you do on a bread box instead of a carving board you have a reflective panel that doubles and
even triples the amount of light heat energy !

ANd this reflective panel drop door can be angled to the correct angle to reflect the suns rays, and then when you close it up the reflective surfaces help
retain the heat. up to 85% if built right !

We are definitely gaining on this build, tank and collector as one ! Best Big AL