Amberwolf's DIY solar water heater
- Thread starter amberwolf
- Start date
Harold in CR
100 kW
The Blue line, is cold into the solar tank ?? Do you remember what I said about that plastic tube on the cold water supply line in the storage tank ?? IF that is still in there, you are taking COLD water from the bottom of the storage tank and pushing it directly into the solar tank.
Why do you have 2 cold water supplies hooked up. If you use the one from the solar tank, it will do the thermo siphon, by taking it from the BOTTOM, where the second cold water supply is hooked up. That should go back to the solar tank. Any time you use hot water faucet, it should take water from the solar tank to feed the storage tank.
Am I reading that diagram correctly ?
Why do you have 2 cold water supplies hooked up. If you use the one from the solar tank, it will do the thermo siphon, by taking it from the BOTTOM, where the second cold water supply is hooked up. That should go back to the solar tank. Any time you use hot water faucet, it should take water from the solar tank to feed the storage tank.
Am I reading that diagram correctly ?
Yes, I do remember; and as far as I can see that's the only way to circulate the water properly so it all gets heated, right? (or to use the drain as the cold side connection, which I haven't got the right plumbing connections yet, unless I use garden-hose stuff that I don't trust to hold the pressure).Harold in CR said:
Otherwise it's just gonna push the already-heated water from teh top of the storage tank (whcih i CANNOT modify as it does not belong to me; it's part of the house) back out to teh solar tank again, whether circulation was thermo or pump, isn't it?
The blue line is cold side, red line is hot side. Arrows indicate circulation direction when pump operates (and if thermosiphon was working).
The pressure supply of fresh cold water into the system from the house is exactly like the diagram says:
If I"m using water directly from the solar tank (like now, when it's not making hot enough water to mix with the storage tank and still be usable, and thermosiphon isn't working anyway), then I use the pressure supply at the drain of the solar tank. This one won't be used once I solve the problem of circulation and sufficient heat, unless i just really need superhot scalding water for some reason. :lol:
If I'm using water directly from the storage tank, like I normally would, I use the pressure supply at the drain of the storage tank. This is the only supply there will be once this battlestation is fully operational.
Normally both of them are turned off at the wall taps, so that if there is a plumbing failure I only lose the water that was in the system, at worst.
Harold in CR
100 kW
You should always feed the storage tank FROM the Solar tank. It will heat up first thing in the morning, up until you use the storage tank. When you feed cold into the storage from the house supply, you defeat the thermosyphon. With the pipe down inside the cold supply of the storage tank. There is no way for the water to circulate by itself. You just want to create a giant loop of water within the system, and, have the cold supply only feeding the solar tank.
The hot water creates what little pressure is used to push the cold water down in the storage tank, where it migrates to the Solar tank. There is no need to modify the storage tank hot water side. With the tube in the cold side of the storage tank, there is where your blockage is. Cold will not rise up to the top of the storage tank, to exit to the solar tank through that tube. Just use the drain to feed back into the solar tank. You should feed the cold water directly to the house, not through the storage tank. It ALWAYS wants to be in the heating, thermosyphon stage. Cold supply to the solar tank, nothing else in that system.
The hot water creates what little pressure is used to push the cold water down in the storage tank, where it migrates to the Solar tank. There is no need to modify the storage tank hot water side. With the tube in the cold side of the storage tank, there is where your blockage is. Cold will not rise up to the top of the storage tank, to exit to the solar tank through that tube. Just use the drain to feed back into the solar tank. You should feed the cold water directly to the house, not through the storage tank. It ALWAYS wants to be in the heating, thermosyphon stage. Cold supply to the solar tank, nothing else in that system.
Ok. Makes sense.
However, the thermosiphon isn't working anyway, even if I don't use the system at all (including keeping the pressure supply shut off to both tanks) for a couple of days. It *did* work once, but *backwards*, with the hot water warming up the *cold* side PEX. I don't know how long it was working, except it was only on one day (whcih was not even as warm or sunny as previous or next days). I have no idea how it even *could* work like that, but it did (and it's never worked the "right" way).
EDIT: Forgot this part: I'll have to see about making up an adapter to get the cold side PEX with NPT threading onto the storage tank drain with "gardenhose" threading. The problem is that the adapter has to survive the pressure of the weight of water in the tanks, plus any additional pressure from the input of new water before I turn on the tap, when I am going to use the hot water from the system.
I'm still working on getting a bigger and better "breadbox" built, to capture more heat in the sometimes shaded spot it is forced to be in right now (due to available length of PEX). If the water in teh solar system gets hot enough, hopefully it will circulate on it's own.
If it doesn't, I'll setup a timer to run the pump every so often and keep "kickstarting" it. Determining how often to do it will just take some experimentation. :/
I'd still like to stick this thing on the roof at some point, but right now all the friends I have that could/would help with getting it up there aren't available, probably till after the new year.
However, the thermosiphon isn't working anyway, even if I don't use the system at all (including keeping the pressure supply shut off to both tanks) for a couple of days. It *did* work once, but *backwards*, with the hot water warming up the *cold* side PEX. I don't know how long it was working, except it was only on one day (whcih was not even as warm or sunny as previous or next days). I have no idea how it even *could* work like that, but it did (and it's never worked the "right" way).
EDIT: Forgot this part: I'll have to see about making up an adapter to get the cold side PEX with NPT threading onto the storage tank drain with "gardenhose" threading. The problem is that the adapter has to survive the pressure of the weight of water in the tanks, plus any additional pressure from the input of new water before I turn on the tap, when I am going to use the hot water from the system.
I'm still working on getting a bigger and better "breadbox" built, to capture more heat in the sometimes shaded spot it is forced to be in right now (due to available length of PEX). If the water in teh solar system gets hot enough, hopefully it will circulate on it's own.
If it doesn't, I'll setup a timer to run the pump every so often and keep "kickstarting" it. Determining how often to do it will just take some experimentation. :/
I'd still like to stick this thing on the roof at some point, but right now all the friends I have that could/would help with getting it up there aren't available, probably till after the new year.
dnmun
1 PW
i found all of my used solar hot water panels on CL and in the classified of the denver newspaper. but that was back in the late 80's early 90's when people were ditching their systems after using them for a few years until something failed which they did not wanna pay to fix and then they removed them when the roof was replaced usually.
you may find something similar there and panels will be much more effective. also you may find the delta controller and small pumps in the same ads.
you may find something similar there and panels will be much more effective. also you may find the delta controller and small pumps in the same ads.
Harold in CR
100 kW
Also, talk to plumbing suppliers. They usually have to cart the tanks away for the customer. Gas water heaters use a chumney pipe inside the tank. Those are the best kind to use. You can't really cut or burn holes in the tanks, because of the glass type lining inside. That will just allow the water to get rusty colored, if not used for a few days, like vacation times, etc.
Yes, panels are a good way to go. It's just hard to do it cheaply like some of us have to do.
Yes, panels are a good way to go. It's just hard to do it cheaply like some of us have to do.
dnmun
1 PW
i was really fortunate because i was able to buy a buncha the big kennametal copper panels for $80 each and some others that were 3x6' for $60 each. less than scrap metal prices. but copper was cheaper back then too. people wanted to ditch their panels then too so they were readily available since so many people did not wanna keep their system working after reagan removed the solar panels from the white house.
Harold in CR
100 kW
I was doing all this in the late 70's-early 80's. Yes, everything was lots cheaper, back then. You did get a good deal on those copper panels. People are really stupid to do things, then, undo them because of a politicians ideas. 
Reagan was the cause of us shutting down the Alternative energy business when he cut the investment tax credits.
Reagan was the cause of us shutting down the Alternative energy business when he cut the investment tax credits.
I've been hunting for those types of solar water heating units since I saw the ones Evoforce has, something like 3+ years ago. Might be 4+, can't remember. So far, no luck. Foudn a few people with them sitting around unused, some said for more than a decade, but none would part with them, cuz "eventually" they're going to use them. (I understand the feeling) Nobody selling any though.
Next best thing that I've been looking for is piping and interconnects that I can use to make my own. I don't have enough piping yet, and no interconnects.
I've also been checking around for any other tanks, gas or electric, but so far haven't been able to get any of them for free or money. It's been a problem with quite a few things (old car batteries, anything made of metal, glass patio doors, various electronics) in the last couple years, either because of regulations, perceived scrap value of things, or supposed liability issues, etc. Or just plain stubbornness on the part of those with the items. Most businesses simply "can't" let me have or buy used things from them, and most individuals aren't willing to.
Every so often I find an opportunity, but not for another tank yet.
So for now, it's up to the tank I've got.
And so....I'm figuring out how to set up the tank in a taller breadbox that'll have the mirror on top and behind the tank to get some reflected sunlight onto it for as much of the day as I can. The mirror is needed because at the farthest point I can get the PEX stretched out to, it's in partial tree shade for almost all of the day now. The roof is the only other option, but I haven't found my pulleys yet to rig something up I can haul the tank up there by myself with.
Well, actually I guess I could build a scaffold on the ground that would put the tank up in the sun, but it'd be less dangerous on the roof--no chance of Yogi running headlong into the scaffold and somehow knocking it over or destabilizing it. (he does that to the sheds and trees fairly frequently when chasing cats out of the yard...and 130lbs of dog moving at full tilt is a lot of momentum!)
Next best thing that I've been looking for is piping and interconnects that I can use to make my own. I don't have enough piping yet, and no interconnects.
I've also been checking around for any other tanks, gas or electric, but so far haven't been able to get any of them for free or money. It's been a problem with quite a few things (old car batteries, anything made of metal, glass patio doors, various electronics) in the last couple years, either because of regulations, perceived scrap value of things, or supposed liability issues, etc. Or just plain stubbornness on the part of those with the items. Most businesses simply "can't" let me have or buy used things from them, and most individuals aren't willing to.
Every so often I find an opportunity, but not for another tank yet.
So for now, it's up to the tank I've got.
And so....I'm figuring out how to set up the tank in a taller breadbox that'll have the mirror on top and behind the tank to get some reflected sunlight onto it for as much of the day as I can. The mirror is needed because at the farthest point I can get the PEX stretched out to, it's in partial tree shade for almost all of the day now. The roof is the only other option, but I haven't found my pulleys yet to rig something up I can haul the tank up there by myself with.
Well, actually I guess I could build a scaffold on the ground that would put the tank up in the sun, but it'd be less dangerous on the roof--no chance of Yogi running headlong into the scaffold and somehow knocking it over or destabilizing it. (he does that to the sheds and trees fairly frequently when chasing cats out of the yard...and 130lbs of dog moving at full tilt is a lot of momentum!)
Harold in CR
100 kW
You got a helmet for the poor pooch ?? :lol:
Wife and I put our panel on the roof, by sliding it up a long board. Once on the balance-tipping point, I got up on the roof, while she raised up the bottom of the board, so I could slide it off without breaking the glass.
Working alone is an art. Requires lots of thinking-planning. Yesterday, I moved an 8' log that must weigh 250#, about 200 yards to near the sawmill. I took the trust wheelbarrow and tipped it up frontwards, slid it under the log, then chained the log to the handles. When I tipped it back to normal position, the log was perched on the front edge of the tray, and the other end was dragging on the ground. It was a bit of a struggle to balance the thing, but, I backed up all the way with not a lot of effort.
Just finished cutting a few boards from it using the chainsaw, until I get the mill finished.
If you have a wide board or a couple of them, or, even a ladder, you can roll that tank up on the roof, using a rope, tie it to the top of the ladder that is resting against the edge of the roof. Run the ropes down, under the tank, then back up to the top and then back down. Use the rope so it runs near both ends of the tank. It will be like 2 ropes, actually. Then, as you roll the tank, take up the slack, get another position, and roll it further up, taking up the slack.
Google parbuckling. That's what this is called. Lots of youtube videos.
This way, if you need a little break, the ropes have the tank. Finally, as it gets to the top, you have to crawl up there and shove it over the end of the ladder, landing on the roof. Simple as it can be. I think, even with your bad knees, you can do this. Just try to keep the dogs inside while you do this, to keep from being distracted or knocked around.
Wife and I put our panel on the roof, by sliding it up a long board. Once on the balance-tipping point, I got up on the roof, while she raised up the bottom of the board, so I could slide it off without breaking the glass.
Working alone is an art. Requires lots of thinking-planning. Yesterday, I moved an 8' log that must weigh 250#, about 200 yards to near the sawmill. I took the trust wheelbarrow and tipped it up frontwards, slid it under the log, then chained the log to the handles. When I tipped it back to normal position, the log was perched on the front edge of the tray, and the other end was dragging on the ground. It was a bit of a struggle to balance the thing, but, I backed up all the way with not a lot of effort.
Just finished cutting a few boards from it using the chainsaw, until I get the mill finished.
If you have a wide board or a couple of them, or, even a ladder, you can roll that tank up on the roof, using a rope, tie it to the top of the ladder that is resting against the edge of the roof. Run the ropes down, under the tank, then back up to the top and then back down. Use the rope so it runs near both ends of the tank. It will be like 2 ropes, actually. Then, as you roll the tank, take up the slack, get another position, and roll it further up, taking up the slack.
Google parbuckling. That's what this is called. Lots of youtube videos.
This way, if you need a little break, the ropes have the tank. Finally, as it gets to the top, you have to crawl up there and shove it over the end of the ladder, landing on the roof. Simple as it can be. I think, even with your bad knees, you can do this. Just try to keep the dogs inside while you do this, to keep from being distracted or knocked around.
Harold in CR said:
If i thought he could or would keep it on, I'd try a modified bike helmet.
I have a ladder that is not quite tall enough, but I supposed I could use cargo tiedowns to crank down hard on a board to it to extend it.
However, if I can find my pulleys, it would help me a lot. The only thing I have for rope is paracord, so that's what I'd have to use.
I'm sure I'll have to take multiple breaks, so it's gonna require something like this. I'd keep the dogs inside so I wouldnt' have to worry about it or me falling on them when I make a mistake.
If I could make it work on teh ground it'd be better, cuz thermosiphon could work and that'd simplify the system a lot (no pump needed, no control system, etc).
The fingers
10 TW
Who needs a helmet when you've got a keg collar! :lol:Harold in CR said:
He just needs a fatter tire for better suspension on those big bumps:
Oh, and I forgot some data: Last couple of days it's been getting a tad cold before morning--it was 39F night before last, and 38F last night. It's getting down to 55F by 730pm, and half an hour later it's dropped another degree.
The tank tent (air temp) is down to arond 60F by morning, and is already down to 70F now (8pm) (from a peak of only 110F, instead of the 130-140F it had been getting to not long ago).
So, it's not getting as hot partly because it's having to start from colder temps, it's getting colder because it isnt' getting as hot to start with. :/ Vicious circle.
Some of it I can fix with insulation when I make the better breadbox. That should also help with not getting as hot in the first place. Fixing the thermosiphon by moving the storage cold outlet to the base of the storage tank ought to help too.
If those don't work I guess it's on up to the roof.
The tank tent (air temp) is down to arond 60F by morning, and is already down to 70F now (8pm) (from a peak of only 110F, instead of the 130-140F it had been getting to not long ago).
So, it's not getting as hot partly because it's having to start from colder temps, it's getting colder because it isnt' getting as hot to start with. :/ Vicious circle.
Some of it I can fix with insulation when I make the better breadbox. That should also help with not getting as hot in the first place. Fixing the thermosiphon by moving the storage cold outlet to the base of the storage tank ought to help too.
If those don't work I guess it's on up to the roof.
Mark-az
1 mW
Joined recently and found this thread and had a thought about thermo-siphoning.
I read/saw a thermo ventilation system that used a tall chimney as the air exit. They mounted a metal plate on the East side of the chimney to get the air movement started in the morning.
I wonder if a piece of copper pipe, inside your insulating box, between the solar tank's high exit and the pex tubing would start your siphon. The copper pipe section would have to get direct sunshine...
I have also read about using thermosiphoning to heat pools and everything I read says you need a check valve to prevent back flow when the sun goes down.
I would love to use the sun to heat our pool; but, you have to be able to put the solar panels below your pool... and our house is in the flats of Tempe.
HTH,
Mark
I read/saw a thermo ventilation system that used a tall chimney as the air exit. They mounted a metal plate on the East side of the chimney to get the air movement started in the morning.
I wonder if a piece of copper pipe, inside your insulating box, between the solar tank's high exit and the pex tubing would start your siphon. The copper pipe section would have to get direct sunshine...
I have also read about using thermosiphoning to heat pools and everything I read says you need a check valve to prevent back flow when the sun goes down.
I would love to use the sun to heat our pool; but, you have to be able to put the solar panels below your pool... and our house is in the flats of Tempe.
HTH,
Mark
You can still use the sun to heat the pool, but you'd have to stick a little pump in there (like I did in mine, but much smaller).
It doesn't have to mvoe water quickly, just enough to keep the warm water going. Even with the energy used by the pump, it'd still be a lot cheaper to use the solar heat than pay for the energy to heat it, assuming you can find or make the heater panel cheaply enough.
It doesn't have to mvoe water quickly, just enough to keep the warm water going. Even with the energy used by the pump, it'd still be a lot cheaper to use the solar heat than pay for the energy to heat it, assuming you can find or make the heater panel cheaply enough.
Mark-az
1 mW
amberwolf said:
Black pvc drip line coils on the roof, the 1/2" stuff that feeds the drip lines.
Good idea. A small solar panel and a small pump...
We don't heat the pool, so this setup would let us use it earlier and later in the year.
I'll be hunting on craigslist now...
Harold in CR
100 kW
One project we had, was, to heat a pool that was inside the house in an add-on. We used a 250 gallon Butane tank, with cast iron doors. Wrapped 1" M copper tube around the "outside" to heat the water. WE wanted to put it INSIDE the stove, but, the local wood stove sellers convinced the client that the copper would melt. 
Ennyhoo, I got the job of silver soldering all the copper tubing from the stove to the pool and back. We modified the circulation outlets to take the 1" copper tube and we were NOT allowed to insulate the lines. Tried our best to convince the clients that we NEEDED to insulate, but, same stove sellers told the clients that the space around the pool would get heated and help to keep the pool temps warmer than without.
The pool was built inside a railroad tie crib, so, was raised up and there was plenty of room around the outside to crawl in and work. 9" thick creosoted ties will INSULATE the pool, NOT help to keep it warm. We figured the pool would not gain 5° F with that set up.
Never heard how it went, because, a month later I left Arkansas and went to Florida to work, then, 3 months later, my family was moved to Florida.
Mark-as, Have you tried the solar bubble floating mats for pool heating ? It is supposed to keep some of the heat from escaping at night, while helping warm the water from the sun, during the day.
to heat the water. WE wanted to put it INSIDE the stove, but, the local wood stove sellers convinced the client that the copper would melt. Ennyhoo, I got the job of silver soldering all the copper tubing from the stove to the pool and back. We modified the circulation outlets to take the 1" copper tube and we were NOT allowed to insulate the lines.
Tried our best to convince the clients that we NEEDED to insulate, but, same stove sellers told the clients that the space around the pool would get heated and help to keep the pool temps warmer than without. The pool was built inside a railroad tie crib, so, was raised up and there was plenty of room around the outside to crawl in and work. 9" thick creosoted ties will INSULATE the pool, NOT help to keep it warm. We figured the pool would not gain 5° F with that set up.
Never heard how it went, because, a month later I left Arkansas and went to Florida to work, then, 3 months later, my family was moved to Florida.
Mark-as, Have you tried the solar bubble floating mats for pool heating ? It is supposed to keep some of the heat from escaping at night, while helping warm the water from the sun, during the day.
Mark-az
1 mW
Harold in CR said:
We 'bubble wrapped' the pool for a couple of years. The floating bubble wrap added 1 month on both sides of the swim season. But the bubble wrap breaks down and then you have to throw it away/recycle and buy another one. We stopped buying them when the kids stopped swimming all the time.
It's about time to move the tank, one way or another: even at "shutdown time" around 3pm (when it gets no more direct sun), it isn't even reaching 100F air temp inside, and the water itself is no longer even body temperature rigth at the closest hot tap to the system input in the house.
I tried tripling the insulation, put on as soon as the sun went past that shadow point and removed as soon as the sun is up high enough to shine on the tank at all, with all of the blankets and sheets I had unused, and it hasn't helped much (got me another 3-4 degrees, by keeping it from cooling off as much at night), but the problem isn't as much the loss of heat but instead the lack of getting it in there in the first place.
So I'm going to see if I can manage to get it up on the roof and enclosed and insulated this Wed/Thurs when I'm off.
In the meantime, for what I think is the first or second time since I started this project, I'm going to have to use the electric water heater (storage tank) as an actual powered heater. Water supply is now just way too cold to use directly as a shower and there is not enough "warm" water from teh solar tank to shower in. I don't know how long it's gong to be before I have the solar system functional enough to use for that again, so for now I'll have to live with the energy use. It's not that bad cost wise, as my elecric bill is down to just over $30 last month, and probably less this month (depending on the water heating costs it could be more), but I prefer teh idea of not using up energy and creating more heat for something so trivial as just washing up.
Tomorrow if there's time before work I will disconnect the solar tank's pipes from the storage tank in preparation for drainign the solar tank and getting it up on the roof for the next stage of experiments.
I tried tripling the insulation, put on as soon as the sun went past that shadow point and removed as soon as the sun is up high enough to shine on the tank at all, with all of the blankets and sheets I had unused, and it hasn't helped much (got me another 3-4 degrees, by keeping it from cooling off as much at night), but the problem isn't as much the loss of heat but instead the lack of getting it in there in the first place.
So I'm going to see if I can manage to get it up on the roof and enclosed and insulated this Wed/Thurs when I'm off.
In the meantime, for what I think is the first or second time since I started this project, I'm going to have to use the electric water heater (storage tank) as an actual powered heater.
Water supply is now just way too cold to use directly as a shower and there is not enough "warm" water from teh solar tank to shower in. I don't know how long it's gong to be before I have the solar system functional enough to use for that again, so for now I'll have to live with the energy use. It's not that bad cost wise, as my elecric bill is down to just over $30 last month, and probably less this month (depending on the water heating costs it could be more), but I prefer teh idea of not using up energy and creating more heat for something so trivial as just washing up. Tomorrow if there's time before work I will disconnect the solar tank's pipes from the storage tank in preparation for drainign the solar tank and getting it up on the roof for the next stage of experiments.
Yesterday I finished disassembling the whole solar water heater system in preparation for moving it up on the roof, inside a new (yet to be built) breadbox.
I've pondered several design ideas, with teh simplest being essentially a framed-up version of the same "tent" that I already had down on teh ground.
The ground version was just taped together--the one on the roof would have a wooden frame the plex pieces would all be screwed into, and a metal base frame that the tank would be strapped to and evertying else bolted down to, and styrofoam sheets layered between just under the tank and the roof itself, to help keep heat inside it instead of escaping down thru the roof into the house.
It'd have clear plastic east and west ends, made out of smaller thinner pieces of plex and sheet plastic I had salvaged from the remodels at work and from Mark, double-layered with an air gap. That should help trap heat inside at the ends, including when it has no sun on it. Both north and south tent sides would be the large thick plex panels from Mark. I have found some of my gate hinges that can be used to allow opening the unit up; they'd go on the bottom end of the south face of it, so I can fold the south face panel down and out, to access the tank and plumbing and pump and wiring when necessary (which will hopefully never have to be used).
Above the ends of the tent would be a pair of tubes following the shape of the tent itself, but with a big radius curve at the apex, to hold an insulation sheet (probably a blanket or set of layered blankets, with a plastic cover to help keep rain off of them), that I can pull over the whole thing at night or when it's raining, to help hold in the heat better when no sun is on it (so that when it gets sun again it doesn't have to heat it up as much, since less heat would be lost from it).
Also considering two insulation-covered thick "endcaps" that would hinge from the bottom, and fold up against the east and west ends of the tent, with a pull of a cord. Weighted or sprung against that cord so that when the cord is not being pulled down they'll lay back down against the roof and allow heat into the sides. Painted flat black on the inside so they get more heat when they are open, and make the roof hotter there in that area to help the tank heat more too.
Possibly do the same thing (instead of the frame and blanket layers) for the north and south tent faces. Then I only open the north face for wintertime, spring, and fall, and open both for summer because the sun will be overhead and north of the unit then, and having it all clear will let more heat in.
The "tent" shape is probably the most stable without bolting to the roof, with most of it's mass well below the halfway point in it's height, and most of it's surface area below that as well, so ti'd be harder for winds to tip over even if they got as high as earlier this season when trees were uprooted around town.
The other shapes I've considered are less like an isoceles triangle the tent would be, and more like a rigth triangle, with the perpendicular sides beign the base and the north side whcih would also be tall, with the tank held vertically (instead of horizontally like in the tent), and the tank leaning with the top toward teh north and the bottom toward the south, at something like a 45 degree angle, or possibly even closer to parallel with the roof surface. However, this would get less efficient during summer, though as hot as it is then that would not really affect it's usefulness. :lol: It would possibly make it better at heating in the early morning and evening, though, if the sides of the tank were facing east/west instead of north/south.
But it *would* make ti much more susceptible to winds, so perhaps simply turning the tent so it's large sides are east/west and ends are north/south would be a better compromise.
The roof angle is very shallow where it would go, but does still make it face more north if I do that with the tent perfectly parallel with the roof. If I build the tent so that ti's north end is raised up, however, I can make it so it is iether completely level, or actually faces south a little, without making it quite as vulnerable to winds as the other version would be.
I've just about convinced myself the tent is the simplest to build and the most wind-resistant, so input from others with any experience in this is appreciated.
Also, I think the "petal" style of hinged-base insulation covers for all four sides would be the best and certainly easiest to operate method of covering it when there's no sun on it, and is also the most wind-tolerant (or can be made so, much more than blankets on a pipe frame, which will act like a sail or parachute in the wrong wind conditions).
If my descriptions are not sufficient, I can post drawings. HAvent' made any yet as I'm still playing in my head with the ideas.
I've pondered several design ideas, with teh simplest being essentially a framed-up version of the same "tent" that I already had down on teh ground.
The ground version was just taped together--the one on the roof would have a wooden frame the plex pieces would all be screwed into, and a metal base frame that the tank would be strapped to and evertying else bolted down to, and styrofoam sheets layered between just under the tank and the roof itself, to help keep heat inside it instead of escaping down thru the roof into the house.
It'd have clear plastic east and west ends, made out of smaller thinner pieces of plex and sheet plastic I had salvaged from the remodels at work and from Mark, double-layered with an air gap. That should help trap heat inside at the ends, including when it has no sun on it. Both north and south tent sides would be the large thick plex panels from Mark. I have found some of my gate hinges that can be used to allow opening the unit up; they'd go on the bottom end of the south face of it, so I can fold the south face panel down and out, to access the tank and plumbing and pump and wiring when necessary (which will hopefully never have to be used).
Above the ends of the tent would be a pair of tubes following the shape of the tent itself, but with a big radius curve at the apex, to hold an insulation sheet (probably a blanket or set of layered blankets, with a plastic cover to help keep rain off of them), that I can pull over the whole thing at night or when it's raining, to help hold in the heat better when no sun is on it (so that when it gets sun again it doesn't have to heat it up as much, since less heat would be lost from it).
Also considering two insulation-covered thick "endcaps" that would hinge from the bottom, and fold up against the east and west ends of the tent, with a pull of a cord. Weighted or sprung against that cord so that when the cord is not being pulled down they'll lay back down against the roof and allow heat into the sides. Painted flat black on the inside so they get more heat when they are open, and make the roof hotter there in that area to help the tank heat more too.
Possibly do the same thing (instead of the frame and blanket layers) for the north and south tent faces. Then I only open the north face for wintertime, spring, and fall, and open both for summer because the sun will be overhead and north of the unit then, and having it all clear will let more heat in.
The "tent" shape is probably the most stable without bolting to the roof, with most of it's mass well below the halfway point in it's height, and most of it's surface area below that as well, so ti'd be harder for winds to tip over even if they got as high as earlier this season when trees were uprooted around town.
The other shapes I've considered are less like an isoceles triangle the tent would be, and more like a rigth triangle, with the perpendicular sides beign the base and the north side whcih would also be tall, with the tank held vertically (instead of horizontally like in the tent), and the tank leaning with the top toward teh north and the bottom toward the south, at something like a 45 degree angle, or possibly even closer to parallel with the roof surface. However, this would get less efficient during summer, though as hot as it is then that would not really affect it's usefulness. :lol: It would possibly make it better at heating in the early morning and evening, though, if the sides of the tank were facing east/west instead of north/south.
But it *would* make ti much more susceptible to winds, so perhaps simply turning the tent so it's large sides are east/west and ends are north/south would be a better compromise.
The roof angle is very shallow where it would go, but does still make it face more north if I do that with the tent perfectly parallel with the roof. If I build the tent so that ti's north end is raised up, however, I can make it so it is iether completely level, or actually faces south a little, without making it quite as vulnerable to winds as the other version would be.
I've just about convinced myself the tent is the simplest to build and the most wind-resistant, so input from others with any experience in this is appreciated.
Also, I think the "petal" style of hinged-base insulation covers for all four sides would be the best and certainly easiest to operate method of covering it when there's no sun on it, and is also the most wind-tolerant (or can be made so, much more than blankets on a pipe frame, which will act like a sail or parachute in the wrong wind conditions).
If my descriptions are not sufficient, I can post drawings. HAvent' made any yet as I'm still playing in my head with the ideas.
Solar water heater is still not back in operation; with the rain this week I may not get it done for another week or more. :/
For now I still have to use electricity to heat water for showers (it's too cold to shower in the unheated water, which is around 55F at the cold tap, and 65F or so at the unheated hot tap after it's gotten water from the storage tank up thru the house pipes to the tap).
I've added three insulation layers to the storage tank, whcih is presently only connected to the wall just like it originally was, with no external piping. The first layer is some 1"-thick plastic-wrapped padded yellow fibrous insulation, which I don't know the composition of, but comes sometimes in our frozen-food shipment boxes (whcih also use some dry ice to maintain them at frozen temperatures) as insulation during shipping. I used to have a whole bunch of that stuff, but it seems to have disappeared during the post-fire cleanup, as I haven't found any of it in the sheds yet. Was planning on using some of it to wrap pipes in outside, eventually. Have to save it from work again, i guess--but they don't use it very often. Must be more expensive than styrofoam boxes, which is more typical to get from them--they used to use it all every week, but now it's not very oftne at all.
Next layer is some thin blankets, and outside that is a big puffy blanket.
The insluation helps a lot, because if I heat a tank of water to 120F, then take a shower right then, shutting off power before the shower, it'll still be in the low-mid 90s F the next day, still usable for a shower, with the present ~60-65F room temperature in the back room and utility room. Without the insulation around the tank, it is not more than a couple of degrees above ambient under the same conditions.
Adding a thin blanket across the entryway (no door there to close) of the utility room to help block airflow in and out of there traps a little more heat for a little longer, too, though doesn't seem to make a measureable difference in temperature of the water, in the very small sample of measurements so far (just a few days since just before taking the solar tank down).
I've pretty much decided to use the tent in north-south orientation for the ends, and make the frame so it props up the north end higher, helping teh whole thing face south a little for more direct sunlight in it past morning and before evening.
I'm also going to use the "petal" type of cover, hinged at the bottom and cabled to pull it upward to close against the tent.
Am trying to figure out a good way to use springs to pull back on them against the cables to pull away from the tank, but haven't figured out a way yet. Will probably have to use two cables, or a single one that is a loop on a pulley, for each of the petal/covers.
The north end will not be a clear plex piece, but instead will be plywood, with the plumbing exiting thru or under that, and lots of styrofoam sheet insulation inside it. All other faces of the tent will be clear for sunlight to enter.
The petals will be (probably) plywood or masonite with stryfoam layers glued or screwed to them, and the big mirror secured to the west side's inner surface, so that it will be usable to reflect sunlight in the morning onot the tank's "dark side" to heat it faster in hte morning. I'll have to manually pull the cable/pulley to angle it periodically to get teh sun on the tank, unless I can make a motor on a timer to do it for me.
The east petal/cover will eitehr be painted black inside, or covered in foil, not sure which will help more. The south end will be painted black inside.
The bottom of the tent inside will be covered in a lot of styrofoam layers, and painted black on the top layer just under the tank.
All of the petal open/close will have to be done manually. Eventually I'd like to make either a light sensor or a timer that operates the motors to close them when the sun isn't shining on the tank anymore, and open htem when it is.
It'd be nice to have the east side close itself once the sun is past zenith and can't shine directly on that side of the tank anymore, to trap more heat in, and have it lower the west side open more to let the sun in more as it gets lower in the west later in the afternoon/evening.
Those are future things, though, as it's enough work to do the manual version and will take some time to find all my parts to do something automatic. I did find two power-window motors i'd saved out of the old '85 Ford LTD, so maybe I can make cable pulls on them to do this with.
For now I still have to use electricity to heat water for showers (it's too cold to shower in the unheated water, which is around 55F at the cold tap, and 65F or so at the unheated hot tap after it's gotten water from the storage tank up thru the house pipes to the tap).
I've added three insulation layers to the storage tank, whcih is presently only connected to the wall just like it originally was, with no external piping. The first layer is some 1"-thick plastic-wrapped padded yellow fibrous insulation, which I don't know the composition of, but comes sometimes in our frozen-food shipment boxes (whcih also use some dry ice to maintain them at frozen temperatures) as insulation during shipping. I used to have a whole bunch of that stuff, but it seems to have disappeared during the post-fire cleanup, as I haven't found any of it in the sheds yet. Was planning on using some of it to wrap pipes in outside, eventually. Have to save it from work again, i guess--but they don't use it very often. Must be more expensive than styrofoam boxes, which is more typical to get from them--they used to use it all every week, but now it's not very oftne at all.
Next layer is some thin blankets, and outside that is a big puffy blanket.
The insluation helps a lot, because if I heat a tank of water to 120F, then take a shower right then, shutting off power before the shower, it'll still be in the low-mid 90s F the next day, still usable for a shower, with the present ~60-65F room temperature in the back room and utility room. Without the insulation around the tank, it is not more than a couple of degrees above ambient under the same conditions.
Adding a thin blanket across the entryway (no door there to close) of the utility room to help block airflow in and out of there traps a little more heat for a little longer, too, though doesn't seem to make a measureable difference in temperature of the water, in the very small sample of measurements so far (just a few days since just before taking the solar tank down).
I've pretty much decided to use the tent in north-south orientation for the ends, and make the frame so it props up the north end higher, helping teh whole thing face south a little for more direct sunlight in it past morning and before evening.
I'm also going to use the "petal" type of cover, hinged at the bottom and cabled to pull it upward to close against the tent.
Am trying to figure out a good way to use springs to pull back on them against the cables to pull away from the tank, but haven't figured out a way yet. Will probably have to use two cables, or a single one that is a loop on a pulley, for each of the petal/covers.
The north end will not be a clear plex piece, but instead will be plywood, with the plumbing exiting thru or under that, and lots of styrofoam sheet insulation inside it. All other faces of the tent will be clear for sunlight to enter.
The petals will be (probably) plywood or masonite with stryfoam layers glued or screwed to them, and the big mirror secured to the west side's inner surface, so that it will be usable to reflect sunlight in the morning onot the tank's "dark side" to heat it faster in hte morning. I'll have to manually pull the cable/pulley to angle it periodically to get teh sun on the tank, unless I can make a motor on a timer to do it for me.
The east petal/cover will eitehr be painted black inside, or covered in foil, not sure which will help more. The south end will be painted black inside.
The bottom of the tent inside will be covered in a lot of styrofoam layers, and painted black on the top layer just under the tank.
All of the petal open/close will have to be done manually. Eventually I'd like to make either a light sensor or a timer that operates the motors to close them when the sun isn't shining on the tank anymore, and open htem when it is.
It'd be nice to have the east side close itself once the sun is past zenith and can't shine directly on that side of the tank anymore, to trap more heat in, and have it lower the west side open more to let the sun in more as it gets lower in the west later in the afternoon/evening.
Those are future things, though, as it's enough work to do the manual version and will take some time to find all my parts to do something automatic. I did find two power-window motors i'd saved out of the old '85 Ford LTD, so maybe I can make cable pulls on them to do this with.
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