Heating Water for Pool

Its a finely tuned value of both. Many people have a career doing just what your doing.

Do some research on heat transfer, and thermodynamics, to run the calculations for your line sizes, temps, exchanges etc.

My layman's opinion is that you will spend much more money pumping water to the attic and blowing air across the coils than you will gain in heater savings.

Maybe I'm missing something.

I agree with the guys above. You can get a pool cover to heat the pool, an attic fan to blow the heat out of the attic. If you have a lot of time on your hands, and like to tinker, this would be a fun exercise. Don't expect great savings, the energy used pumping and blowing will have to be compared to a pool heater.

Consider passive pool heaters, like painting the bottom of the pool a dark color, and a thermal cover to keep the heat in overnight. Insulate the sides, too.

Why don't you surround your pool with solar reflectors to focus sunlight onto it?

Welcome to the insanity. You don't mention where you are located, but above ground pools are common in the warmer climates where they get more usable months. How about harnessing the heat given off by your air conditioner? There are heat pumps that are sold that will heat your hot water for house use. The same thing could be done to heat your pool.

Del had done some experiments with a focused solar water heating tubes. As I remember, there is a half round reflective channel with a black copper tube running along the bottom. It will absorb and focus the sun's energy onto the water tube. With a few of these along the roof, you should be able to get some heat into that pool. Good luck.

Run your pool water slowly thru a DIY radiator made from copper tubing and installed in a box that resembles a flat greenhouse. A 4x20ft one angled towards the sun should do. eBay sells these things pre-fab'd from plastics eBay Solar Pool Heaters

Use two foils: black attached to the bottom, and swimming bubble foil, (lowering evaporation and heat loss to the air), on the surface of water. By changing area of foils (folding/rolling/removing) You can have quite wide span of manual but cheap controlling.

I guess I don't understand the "black plastic lines." Black perhaps to absorb solar insolation? Plastic is not a good thermal conductor so if you plan on using it as a collector or transfer medium - forget it. Thats why you saw the term "copper" used so many times in the earlier posts.

I think there are better approaches; but if you are really set on doing this then perhaps basing the flow rate of your water pumps on the difference in temperature between your inlet and outlets would help you to optimize thermal transfer. The greater the temperature difference the more power applied to the pumps.

What latitude are you at?

What is the solar insolation rate for your area?

Have you considered insulating the outside of the pool?

Hi Gavilan,

You say you don't get the 'black lines'? Well you kinda answered your own statement. It is Black is to absorb the solar energy.

And I agree that metal painted with a 'blackboard' paint is more efficient though you may need a more durable finish like a proper oil based paint if the radiators are set up with no covers.

My friend designed his to have a surround of Plexiglas. But you could easily have half a dozen or more black steel radiators fixed so they do not move, on top of some Styrofoam. My friend used second-hand radiators and Plexiglas I think so the cost does not have to be enormous at all. Just put a little 'elbow grease' and some thought, like perhaps does it need a one way valve etc, into the set up and it will work.

There is no power being used. So any power coming out in the form of hot water is a bonus?

Take care.

If the roof construction is one including conventional rafter bays you may save energy by eliminating the coil fans. You can run the water tubing inside the rafter bays just below the underside of the roof allowing the water to absorb the heat; this is you heat exchanger no fins required. A temperature control valve and variable flow may prevent overheating and or natural convection of course could eliminate a need for a pump too.

To get as much free heat as possible, you need to trap the heat that is there. That means you need to remove the liner and make a floor of closed cell foam insulation and a perimeter wall of closed cell foam insulation, then replace the liner, with a fold to account for the smaller radius. 4 inch foam should do it.

Then you need a night blanket of 2-3" bubble wrap that winds onto a large roll at night. They make them and you can also buy the parts and make your own.

Then you need a heat collector. The best are the convection fed ones that are black copper tubes in a rack with a glass lid. They automatically feed hot in as the sun shines. You need 1" tubing. At night the convection stops.

Using the attic will indeed require some pumping as the warmed water is lighter and will want to stay there. You can use an attic array for pre-warming house water.

If you live where it freezes in the winter, you will need to deal with the solar heater in winter by removing the water, same as you winterize the pool fittings.

The web is full of thousands of do it yourself pool heaters and insulators

http://www.google.ca/#hl=en&source=hp&q=diy+%2B%22pool+heater%22+%2Bsolar&btnG=Google+Search&meta=&aq=f&oq=diy+%2B%22pool+heater%22+%2Bsolar&fp=11da210b3e3653dd

http://www.google.ca/#hl=en&safe=off&q=diy+%2B%22pool+insulation%22+&meta=&fp=11da210b3e3653dd

Be sure to drain it in the winter time (depending on your location) or next summer you wife is going to be asking why you have roof leaks when it is a hot sunny summer day!

Well I supposed you could run all the pipes for recirculating the water past the heat of an airconditioner or some other heat source, and create as much of a closed loop system from salvaged stuff as possible.

Then again you might just paint more and more of the pool inside and out black, till you find the most commonly comfortable water temperature, and be done with it.

When I was a kid being taught to swim, they just pretty much said, "Dive in."

"Swim, or you'll freeze."

P.S. I did do a job in a wave pool where water temps were about 45 degrees, and I had to wear a drysuit and weights to work in the water. We did have to have warming pools so we could warm up and then go back to work in the cold water. I am aware at some point it is more work than fun.

YEP!!!!!

The last part........................and you used to be a boy when you jumped in.

Several years back I saw a magazine article that featured a home made solar panels that were used to heat a swimming pool. The panel was constructed from a sheet of plywood that had a wood frame around it - the frame was approx 4 to 6 inches deep (if memory serves me). The whole thing was painted black. The coil was attached to the board in a zig zag pattern. The inflow and outflow lines were routed thru the sides of the frame. He then filled the whole thing with crushed black stone and topped it off with a sheet of plastic or glass. He used the discharge from the filter pump to push water thru the coils and return it the pool. He set up some valves so he bypass the panel(s) when he reached the temp he wanted. He also had a vent valve so the coils would not rupture when he was not using the panel. He said that the panel produced water temps equal to that of a typical home hot water heater and that the rock retained enough heat to produce warm water for an hour or so after dusk.

You could also try Google

http://www.google.com/search?hl=en&safe=off&sourceid=gmail&ei=oU_RSuu6CZO-lAf4p8GpCg&sa=X&oi=spell&resnum=0&ct=result&cd=1&ved=0CBkQBSgA&q=homemade+solar+panels+for+swimming+pool+heating&spell=1

Best of luck to you.

Ed

PS: Have you looked into a "solar cover" for the pool that you could use when the pool is not in use?

I like this solution. You can build the panels for very low cost maybe even utilize some of the stuff we all have lying about. You don't have to buy any pumps or consume more kW's than you presently do. The stone filling in the panel would have considerable thermal mass so the water outlet temp should be rather stable. There would be no climbing on the roof and running untold feet of pipe or tubing or working in the attic if you located the panel at ground level. If you built some sort of adjustable mount to hold the panel you would be able to track the sun as it moves across the sky. I bet I could build one for under $100. Considering that most of us probably pay 15 to 20 cents per kWh this thing will pay for it self in practically no time. I think I could build one in an afternoon. I will most likely give it a shot next spring.

It may not be a good idea to directly expose the pool with solar light as that may also become a hazard. Perhaps a smaller pond where solar light reflector can heat the water and connecting pipe channels can exchange heat to pool water. You can also have valves to store hot water and on demand inject hot water and regulate heat.

Way, way.way too complicated

Always wanted to use the return gases from my evaperator of my heat pump here in Florida and a heat exchanger to do the same job with the added benefit of less compressor work for the return cycle...

All my HVAC 'EXPERTS' say its is not possible.....but I wonder if we ...

--Duck

There are A/C units that have water cooled condensers. Boats use them. Perhaps one could be modified for home use.

You could join the Polar Bear Club and skip heating the pool altogether!

The pipes in the attic amount to a crude, but perhaps effective, solar collector. What kW is your existing heater? Correlate that to the insolation values at your location. [I suspect it would take a pretty large solar panel(s).] Posts 14 and 15 are on an intriguing track; this should be an ideal application for a heat pump, but it would be a special design on account of the unusual temperatures/pressures and low compression ratio.

I'm not sure I have any compressor ratings for such conditions, but I will try to add more later. Good luck!

Hi Andy,

Great thread?

Just shows you, there is more than one way of killing a cat!

Take care.

YUP!!

Hi Andy,

Like it!

The other extreme is, "if it aint broke, don't fix it"?....... Well sort of!

take care

Dead right again my friend....

Seen at a small motel (with a pool) in the mountains of Massachusetts. The water being circulated in the pool could be re-routed thru a back-and-forth pattern of black plastic pipe. The plastic pipe was laid out on a sloped, south facing shed roof. In the fall, on a sunny day, the water in the pool was almost tepid.

The maximum heat you can gain in your water is a function of (among other things) the temperature difference between your attic air and the pool water. You only want to heat the water when the ambient temperature is low, likely in the winter. This is when your attic air temperature is also the lowest. So your system will not be working with an efficient temperature difference. As the cold water cools the attic and picks up heat, the temperature difference will get even smaller. Sounds like an excecise in diminishing returns.

Go for high volume. The more you heat the stuff up, the less efficient it will be. Every degree will be a bonus.

With low flow

I installed a secondary water heat exchanger (desuperheater) in my central AC (heat pump). When we cool down the house, the heat is dumped into the pool. Cost about $1500 for material and AC tech time to modify the heat-pump and connect to the pool's pump.

You could also do the opposite and use a heat pump pool heater air to cool down the house and/or attic. This would cut on electrical consumption.

It all depends on what you already have.

Hi there, I have good friend in Sweden that very successfully heat his pool with a simple arrangement using sun radiation heat. He put 100 feet of half inch black PVC hose on his black garafe roof. He use a small circulation pump to circulate the pool water tthrough the hose and back into the pool. It really works great despite its a fair size pool, Sweden is far north with lots of rainy and cloudy days. Plastics like PVC are not that great thermal conductor, but still a cost effective alternative as you can afford a longer hose to compensate for that. My friends roof is nearly horisontal so the hose can't be seen when standing on the ground. Good luck with your project! Tommy

Most pool stores carry solar pool covers, made of very heavy duty blue colored bubble wrap. They really work well, assuming your pool gets several hours of direct sunshine every day. During the summer they almost work too well - the water can easily reach a not-very-refreshing ninety degrees. I think the cost is under $100 for a 21' pool. Not much fun tinkering involved other than to trim it to the shape of your pool, but they are cheap, they work, and they keep the bugs and leafs out of the pool as well.

Hey Captmoosie, you put out some good stuff. Sounds like I'll be busy as a beaver this winter.

Doug

You have a lot of great suggestions. I will add a small bit. I like the idea of zero energy solar projects. The little I know about heating water says you can set up a solar collector but it must be below the level of the pool or storage tank to allow natural convection. The hot water will rise to the pool through one pipe and another will will allow cooler water to flow back down to the collector. It's seems cheaper and easyer than trying to plumb the attic and pump the water around.

Utilize the filter pump to move water thru the solar panel coils. You are paying to run it anyway.

Convection will occur regardless of the orientation

I beg to disagree. As far as I know, convection is a gravity operated phenomenon. Cold air or water is denser or heavier than warm. Gravity pulls it down and it displaces the warmer medium, pushing it upwards.

I have to disagree. I copied this explanation from the website I am listing also. It is the US dept of energy site.

Thermosyphon systems are an economical and reliable choice, especially in new homes. These systems rely on the natural convection of warm water rising to circulate water through the collectors and to the tank (located above the collector). As water in the solar collector heats, it becomes lighter and rises naturally into the tank above. Meanwhile, the cooler water flows down the pipes to the bottom of the collector, enhancing the circulation.

http://www1.eere.energy.gov/solar/sh_basics_water.html

Yes this is correct and if inverted convection will also occur.

I don't follow this. If inverted, and the hot one is on top, no natural convection will occur. I mention this because the original poster noted that he wanted to move hot water from the attic to the pool, presumably at a lower level. The water will have to be pumped, natural convection will not occur.

In my option the water is heated on the rail of the pool or neat the rim of the above ground pool. The discharge is at or near the surface while the feed is at or near the bottom. The water pressure of the pool and the pressure from the heated water allow for free water movement from cold to hot. If you assume a restricted discharge you will allow for the pool to pump the water around and heat itself.

The water will have to be pumped, natural convection will not occur.

Convection will occur, we do it often and several green heating systems operate in this exact fashion. It takes a bit to get going but does function quite well.

Hi wire,

Is 'natural convection' like ermmm, one of those little electric heaters you use in the shed, and when you are finished you chuck it in the pool over-night to give the natural convection of der water?

If anyone is reading this thinking I am a right prune?.......... You are probably correct! But, DO NOT do as I advised above, it will ruin the fire, and burn the water! It'll be ready for a nice cup of coffee though!

Take care.

I guess we are just talking about words. Forced convection is a movement of molecules independent of heat. Natural convection (according to Wikipedia) requires heat.

Your neighbor may have a 'cricket' system, which uses some really neat device to move the water around. I'm not sure how it works, but it doesn't need a pump, I think.

I have a solar hot water system on my building, it uses a pump to bring the hot water from the roof to the storage tank. The house pressure pump moves water to the taps. We also have a second pump to circulate hot water in a loop through the plumbing so hot water is always available at the tap, to conserve water.

Ah but there is a pump! The incoming service supplies the pressure to move the water. Or maybe the cricket thing? I may be wrong but it makes sense that the cold water stays near the bottom of the lake and the warm rises to the top. I've seen several systems over the years that have an ugly tank above the roof ridge and collector panels on the roof itself. I bet those are the themosyphon type. Have you questioned your neighbor about how the water circulates? Or if it does? Or maybe it is just is pushed through by the incoming service one time on the way in?

Back to the pool project: He can use the collector and have the "incoming service" top it off with nice warm water. But from the little I know and have read the tank needs to be above the collector to get the natural circulation, thermosyphon, or what ever we each call it to happen.

What puzzles me is: I understand how it could possibly work with the storage tank above (hot water rises, cold water sinks).

I can't understand how it could possibly circulate if the tank is below the heat collector. It seems to me that the hot water would want to stay near the top of the system and the cold at the bottom.

What am I missing? I guess I havn't seen an explanation, only opinions and statements that "it does work". Please explain the science, principles or whatever it is that makes it happen. As you may remember, I am not an engineer so use simple words I can understand.

Thanks,

Bill

This description seems very incomplete to me, and I (and others as well) do not understand how it works on the basis of this description alone. For instance, if this unpressurized reservoir is in the basement, how does the hot water get to the rest of the house? Where is the coil that is mentioned, and how is it actually connected? What controls the incoming cold water to the tank, so that the tank keeps from overfilling? Is the incoming water pressure known? It's a three-story house, so let's assume for now that the collector is about 30 feet above the reservoir.

I will follow up with a discussion on radiation vs conduction vs convection, including various times of convection such as forced vs natural. Also a variety of thermosiphon applications, of which there are at least two types and several practical uses and layouts. There is one form of thermosiphon that everyone over the age of about forty has probably seen, but for now I will let everyone guess what it is.

I apologize for a typo in my post #71: "various times of convection" should have said "various types..."

Thanks for the clarification. Can you further describe how the pipes are run from the tank to the collector, especially as to which connections are to the top and bottom of each? And any traps, inverted traps (siphons), vacuum breakers, and check valves? I don't know that pipe sizes are critical at this point, but it might be helpful to estimate those as well.

What keeps the collector from simply draining to the tank? It seems that even a small leak, especially near the top, would threaten this plan.

[Another poster mentioned "cricket pump." New term to me, and I couldn't find anything on it. Any ideas, anyone?] [At one time I was hoping to research special-application heat pumps, but the solar ideas seem better; so I will abandon that.]

Because of the vertical distance, it takes about 22 psi to push water up to the collector. Because the tank is atmospheric, there is only 15 psi available. Something doesn't compute here...

If we are talking about just a liquid water siphon, the last statement isn't really correct, but it may give an important clue as to what is actually going on in this system.

An atmospheric-at-bottom column of liquid water, even if cold at the bottom, can be drawn upward at most 34 feet above the tank level, because it starts to boil off before it gets that high. And it is still the atmospheric pressure in the tank that pushes it up to whatever height. (The word "suction" is kind of a misnomer.) In this case, the water in the tank is about 160 dF, which is another big clue. This means the water will start boiling about 23 feet up in the upward pipe. From there on up, it will be a froth consisting mostly of vapor (steam). It is this lesser density that allows the water/vapor combination to rise higher than liquid alone.

I have yet to figure out how the average density in the down pipe can be greater than the average density going up, but that will prove to be the secret. It seems as though there must be some condensation going on in the down side, but I haven't figured that out yet. A FULL geometric description would help, but I will try to guess...

Later, though, because I am still doing the write-up on various types of convection, thermosiphon, etc. At least this is a bit of progress.

Hi Tornado,

Check this site out for solar pool water heating. It has pics and you may understand it a little better?

As wire explained it is two completely separate water systems. And the coil is the heat engine in this case absorbing and or transferring the heat to a colder water system.

All very basic stuff as you will see.

http://www.builditsolar.com/Projects/WaterHeating/water_heating.htm#Basics

This site has links to lots and I mean a whole lot of other sites.

Take care

Thanks for the link. Lots of good info. However, on a quick scan I noticed one blue crossbar in the thermosiphon section that said the tank must be elevated. There were also several pictures of solar thermosiphon heaters with integral tanks at the top. I haven't yet seen a picture or description with the tank below the collector, but this was only a very brief look.

Hi Tornado,

Are you trying to find out more details or, are you looking for one of those thermosiphon's with the hot bit at the bottom?

Do you have a special need for one like that?

The only pool heater I made was, as I have already mentioned in a previous post, made from 4 old flat type water radiators, painted black with copper also painted black, linking them together. There was a fine filter just before the cool poll water was pumps quite slowly into the bottom of the radiators. The warm water was gravity fed (I think) back to the bottom of the pool. These radiators were surrounded on all four edges and on the back with black solar absorbing paint. The front and back face was clear Plexiglas.

End to end was positioned E-W, and the clear faces pointed South, but they also court some Sun from the North as well.

Very simple set up and completely independent of the house. The pool was about 120ft from the home. It had a brick built 'shed' which was the pump and filter room. A small low powered CH pump was used to pump the water through the radiators.

Once up to temperature a pool cover lined with 6" (150mm) of fibreglass insulation, with the pool cover on rails and ti was shaped like a bridge with a 'hump-back' which directed most of the rain water away.

I sent you the link not because it was what I used but because I thought it might make things a little clearer?

Are you specifically interested in solar thermosiphons?

Take care. Sorry to all for any repetition.

Since I live in Ketchikan, solar technology is all but useless for me. What interests me about this discussion is the operation of a different type of thermosiphon arrangement from what I have seen before. No one is describing it in very good engineering detail, and so far I don't see how it works. Eager to learn more. I think that a key item will be all-liquid thermosiphons vs liquid/vapor ones. Thus far everyone seems to be speaking of all-liquid, whereas liquid/vapor should have lots more potential.

I use thermosiphon coolers for refrigeration screw compressor oil, in the range of say 50,000 to 500,000 btu/h. Flooded refrigeration evaporators also operate on the thermosiphon principle of similar Q, although the term wasn't used historically. Ebullient engine cooling is also by thermosiphon. And sidearm boilers. And, as I alluded to before, coffee percolators.

So I guess I don't know a damn thing about thermosiphons.

Hi Tornado,

Can you tell me what you want to use these thermo-siphon principles for and to do what? Are you capable of possibly building this for yourself, or do you want an 'of the shelf' item, and what size is it you want?

You mention you use thermo-siphon coolers? Are they in your house or anywhere that you want to heat? The heat from anywhere, be it from the freezer, fridge, engine of any kind or solar can be used to heat other stuff like water for your home. Despite what you think, solar energy in the cooler or even frozen climates is powerful enough to give you useful heat if the system you build is insulated well.

Whatever kind of heating you use for a fire/s in your house can be redirected and scrubbed to heat anything else, though that in particular is not going to be 'free' to start with.

My suggestion to you, is to start a new question thread or discussion and, in your own words explain what you want, or what you want or wish was possible do achieve a certain target of heating your home........ Just as a for instance! Starting a new thread means anyone can ask you only, (because it is your thread) anything without being off topic.

Have you searched CR4 for any details of an explanation which may fit your situation?

Have you gone to any of the 20 or so links I sent which seem to explain how you can make a thermo-siphon and the many ways you can use them?

I say again, you have asked some questions in this thread but, you have given no detail of what you want to do with the possible use of a kind of thermo-siphon?

You can get back to anyone here or ask admin for help but, I think you should open your own thread.............. Having said that, it is a waste of your our our time if you do not read or at least check out any or all sites which can possibly help you directly or indirectly find the answer you seek.

Just click on: "Ask a Question" or, "Start a Discussion. If you want to it helps to explain exactly what your thoughts are and possibly what you budget is, the ambient Temperature and or wind speed, how the place you want to use this is configured and or how high above the water table, if it is on a slope......... Just explain anything at all to give us, anyone, on this site a chance to fully understand what you are after please, OK? If you do not start your own thread any replies with get confused with the original thread I am writing this on now!

Good luck.

Take care.

Your questions are not to any point. I am not trying to buy, design, or build any thermosiphon system, even though I have designed and successfully used this concept in the past. Nor am I trying to compete with any other practioners in this field. I am only trying to understand a variation that goes against everything I have heard of or understood before, and so far no one has given an even remotely comprehensible explanation. This is no surprise, just as perpetual motion device devotees are no surprise. (They never answer pertinent questions, either.)

Welcome to the club, if that's the club you want to join. I admit that my concerns may not obviously align with the OP's post, but they are better than trucks falling through the ice, for instance. I hijacked this discussion ??

That last (?) or one of the last websites posted by Babybear(?) was so well explained, even I understood what how it works.....and I was VERY sceptical up to that point!!!

Hi Andy,

Appreciate your mention, and I am beginning to loss the will to live!

I know you understand when I say this is bloomin' hard work!

Tornado says "Your questions are not to any point. I am not trying to buy, design, or build any thermo-siphon system, "even though I have designed and successfully used this concept" in the past.

Well perhaps my "Motto" of: "HEAR & you FORGET <-> SEE & you REMEMBER <-> DO & you UNDERSTAND"................. is wrong. It seems there is no 'veracity' after all, in this phrase? IE: Do and you UNDERSTAND? Because he has 'done' but does in no way understands.

How can he 'do' but not understand, or was he just lucky?

Take care.

That last (?) or one of the last websites posted by Babybear(?) was so well explained, even I understood what how it works.....and I was VERY sceptical up to that point!!!

That website you mentioned cracked it for me in a good simple MANner ('cos I am simple MAN you see!!).

Stay fit my friend, you did alright!!!

Hi Andy,

Thanks for the reply post Andy.

I had second thoughts after reading Tornado's last post saying in effect, that I had got all and any advice I thought I had sent in, wrong. The remarks were not kindly received by me.

With regard to his last post it seems perhaps we have to be mind-readers. "Well 'you' said this and I said that, (meaning him and me) rather than using the thread as a discussion he states he never ........ then lists the things he never intended. Well, so say so, you know? Hope you understand this.............. I am trying to chill but with those kind of remarks not least the "??" at the end, was just rude and disrespectful to all helping, or trying to.

I even double checked to see if I had actually sent my post ＃87 that advised him, to open his own thread or Blog.

I really do not mean to insult Tornado or anyone, but, hijacking another thread and 'calling it your own', is not the way to make friends and influence people and, in fact is against the written Rules............ Sorry. End of story. It seems the last three or four long threads I have been part of have had that little bit, to large chunk of 'hijack' of the OP's thread, or question.

Take care

Cool down, its a storm in a teacup, you did nothing wrong.......

He was just a bit slow on the uptake.

No damage done.

Hi Andy,

Thanks for your kind words my friend.

I list you, Kriss, wire and a few others and, indeed Tornado as my on-line friends. Something I know I tend to 'lean' on, perhaps too much.............

Take care

Well done.

aurizon

Wonderful picture.

Here is a free idea, no patents for heating one's pool at no cost.

Every man (for woman - no comments) is a 40W heater so if 100 men enter the pool then next men entering the pool sure will find it hot. Allow community people to use the pool for free in the very morning and then you have it hot for free. Of course they may add up some dead skin and pee to give some flavor so tolerate all that.

If you can have some entry fee then it can cover clean up cost.

Hi Shyam,

Well well, I suppose you would make a lot of friends?

Here is a free idea, no patents for heating one's pool at no cost.

Every man (for woman - no comments) is a 40W heater so if 100 men enter the pool then next men entering the pool sure will find it hot. Allow community people to use the pool for free in the very morning and then you have it hot for free. Of course they may add up some dead skin and pee to give some flavor so tolerate all that.

Hi aurizon,

Thanks and I get the pic, thanks.

Take care

Andy,

Can you please specify the Website and, if it is lengthy, the portion of it where this explanation occurs? Believe me or not, I have tried to look, and I haven't found it yet. I hope it's not just me, overlooking something straightforward.

If I remember correctly, the link was:-

http://www.copper.org/publications/newsletters/cutopics/Ct74/solar_heater.html

I found this MOST informative and it cleared up my sceptism completely.

Originally posted by bwire not Babybear (my mistake), I was too lazy to search back at the time.....

But I hope this helps you....

Have a great Sunday, its 07:10 where I live, just been for a walk with the dog (or she with me, I am never sure......!)

I have checked out this Website already, based on another post, and I have noted that the methanol/water combination adds a further hint to what might be going on (fractional distillation vs evaporation vs liquid density vs difference in height between the up and down columns of a simple siphon). All four principles are relevant. No one else has made these distinctions, and so far as iI can tell, the only explanation in this site says that it works like a coffee percolator. This I do not see. I don't think that a coffee percolator will work if it is turned upside-down, with the reservoir on the bottom. But I am prepared to change this view if presented with a comprehensible explanation.

But I am prepared to change this view if presented with a comprehensible explanation.

I tend to be willing to change my views, seeing is believing

Hi Tornado,

It does work like a peculator, ......... But with a closed system and 15% Ethanol/ Water mix gets to Boiling Point at a lower temp. Ethanol boils at ~75℃ / 173 °F.

A pipe goes from the "Cricket" under pressure (as long as there is sun on it) on the roof to the 'hot tank' via a coil under the tank, where it flows through the coil and the now cooler mixture is pushed round again.

Read it again>

--------------------------------------------------------------------------------------

Edition #74: Spring 1993

"Copper was the only material we could trust to last at least 50 years in our solar water heater." This is how Bob Block, president, Sage Advance Corporation, endorsed the selection of the high-heat-transmission, corrosion-resistant metal for the critical elements in his company's "Copper Cricket."

The Cricket is unique among solar water heaters. It doesn't require any pumps, valves, controls or other moving parts or electric power to function. How can the Cricket operate without the costly complications of competing systems?

The array of copper collector tubes inside the Cricket.

"It functions like a coffee percolator," said Dr. Eldon Haines, the physicist who invented and patented it. Bubbles generated in the 15 percent methanol 85 percent water solution inside the copper collector tubes push the solution up to the header pipe at the top of the roof-mounted unit. Because the sealed system operates under vacuum, the solution inside only has to be heated to 65 F by the sun's rays to start bubbling.

The bubbling solution gathering in the header pipe generates enough head (pumping pressure) to be pushed down to a heat exchanger located underneath the user's existing water tank. There solar heat is trans ferred to the water in the tank. The now-cold solution is then pushed back up to the array of copper collector tubes by the down-flowing hot solution.

The all-copper heat exchanger, which can be located as much as 36 feet below the header, is double-walled. This safety precaution is needed because methanol is toxic. Because the methanol/water combination, unlike pure water, shrinks when it freezes, the copper tubing can never be ruptured by freezing. The systems are warranted for 10 years.

Just how much of a user's annual hot-water load can be provided by the Cricket? The contribution ranges from a substantial 91 percent in sunny Phoenix, Arizona, to a beneficial 41 percent in cooler Boston. Made in Eugene, Oregon, the Cricket is cost effective even in its often overcast home state.

Investing in a Cricket, which costs $2,180 in kit form, can be especially attractive when a building's water is heated electrically. This is because many power companies are subsidizing installations that reduce peak demand. Why are these capacity-shy utilities paying their customers to use less of their product? Because it costs so much and takes so long to add capacity.

The rebates range from $300 up to a whopping $1,400 in Sacramento, California, whose local power company has been deprived of its nuclear capability. Most Crickets are installed in 16 to 20 person-hours by plumbing or heating contractors. A handy homeowner might require as much as 30 hours to mount the 150-pound Cricket on his roof and then tie it to the hot water heating system.

The flat, glass-topped Copper Cricket resembles a skylight when mounted on a roof.

Most of the 1,200 Crickets installed to date are in service in residences. However, Block noted that they are almost universally applicable because all buildings and businesses need hot water. For instance, Crickets have been installed in car washes.

The largest installation is in a remote campsite in Tonto National Forest in Arizona. Tapping the Sun's energy was a requirement—needed electric power is generated by photo-voltaic cells—because of the prohibitive cost (nearly $800,000) of bringing in power from the nearest substation seven miles away.

All the hot water for the campground's buildings is provided by 30 solar heat collectors, mounted in six clusters, that cost a total of $105,000 to install.

Could any material other than copper have been used in the critical parts of the Cricket? As Block put it, "We investigated other materials rigorously; in terms of heat conductivity, resistance to corrosion, workability, seal-ability and longevity, we found no substitute for copper."

Hi Tornado,

I realise this is way off topic, and to the thread OP I apologise.

To Tornado please read again my post # 87.

You may think it is a joke to write at the end of your post "I hijacked this discussion ??" Well you did and have!

Despite a couple of posts from me and several other suggestions you start your own thread and or Blog, you continue writing to this one, and have the temerity to criticize (by using the '??') any, it seems whom advise you otherwise, and really treat the owner of this thread with contempt.

Have you read the Motto at the bottom of my posts, which includes "DO & you UNDERSTAND"?............ You say you have "used this concept", well, I fail to understand how, when you do not, by your own words 'understand' at all.

You are breaking the written Rules of this site Sir.

The 'Solar-Siphon' is a very interesting idea. However, you MUST now start your own thread or Blog to continue this discussion.

This is not meant as any kind of personal insult to you, but you continue to insult the OP by the continued hijacking of their thread.

I will not be answering any other remarks on the solar-siphon from you on this thread. I will of course answer any remarks on the OP's thread idea.

Take care.