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Forum Index : Solar : I’m In Hot Water Now!
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MacGyver Guru  Joined: 12/05/2009 Location: United StatesPosts: 1329 |
[Quote=Tinker] I had no idea the plumbers in good old USA still use stone age pipe bending methods I are not that smart. I've always held to the tennant that "simple is best" but you're right, I completely forgot about pipe benders. I don't think I represent all the plumbers here in the states; just me. My intent here was to have the pipe make as much contact with the flat metal heat sink sheet as possible and ridgid pipe came to mind since soft copper would have to be pressed somehow in order for it to all lay flat on a sheet of metal backing increasing its contact. Had I built the "U" ends using any method, the number of solder connections (a coupling @ each end of the "U") would have been exactly the same. Using copper elbows actually impedes the flow a bit, which in this case is a plus in that it forces the water inside to hang around a bit longer to soak up more heat before passing along. Of course, had I used soft copper, I could have made the entire run out of one tube and had NO connections but I wanted more contact of the copper to the heat sink, so I chose to use hard copper pipe. Another thing here is you have to remember that I am the undisputed "king" of doing things the hard way. I have to guard my social position, ya know! Besides, my signature line says "Nothing difficult is ever easy." so I don't want to give anyone the idea I actually have any real understanding in all this. Good information though, as usual; thanks. Perhaps your advise will help the next guy who stumbles down this path. I'm thinkin it's too late for me. I'm just a member of the hunters & gatherers crew! 
. . . . . Mac Nothing difficult is ever easy! Perhaps better stated in the words of Morgan Freeman, "Where there is no struggle, there is no progress!" Copeville, Texas |
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niall1 Senior Member  Joined: 20/11/2008 Location: IrelandPosts: 331 |
hi Mac thats a pretty neat solar water heating panel there.....solar water heating seems to be the most efficient way of utalising that bright thing in the sky ....very nice work indeed ... we should all be building solar panels like these .....it would save our energy costs ...even in climates not as abundantly sunny as yours they seem a simple way of energy conversion and work really good ... plus its cheap and dosent require hi tech stuff niall |
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| MacGyver Guru Joined: 12/05/2009 Location: United StatesPosts: 1329 |
[Quote=naill1] we should all be building solar panels like these .....it would save our energy costs On the topic of shaving energy costs, I've decided to install as much as I can in the way of energy-saving devices. I have a new house and it's an RV (trailer). I originally wanted to turn everything into 12-volt operation and then try to make enough solar and wind toys to keep the batteries charged. To that end, I've changed all my shop stuff to operate on 12-volt motors and that works fine. I haven't as yet been able to achieve a completely 12-volt lifestyle, but I'm still at it. When it came to lighting, I did an in-depth study and wound up installing 110-volt a.c. fluorescent lighting. The reason is, the cost of enough fixtures to outfit my galley, dining/living room and shop was LESS than just one 12-volt fluoresent lighting fixture; those suckers are expensive! Another reason I didn't stick with 12-volt lighting was the only thing that made any sense were LEDs and no matter how many of those you stack in a fixture, the quality of the light they produce sucks. At any rate, I can use a 12-volt deep-cycle battery and a 450-watt inverter to run ALL my lights, fluorescent and incandescent as well. Next up on my list is a 12-volt clothes washer and a dryer (read that "wringer") -- stay tuned. . . . . . Mac Nothing difficult is ever easy! Perhaps better stated in the words of Morgan Freeman, "Where there is no struggle, there is no progress!" Copeville, Texas |
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Tinker Guru Joined: 07/11/2007 Location: AustraliaPosts: 1904 |
Sorry Mac, I missed the bit that you had hard drawn copper pipes. Assumed everyone uses soft copper pipe for things like that  Also assumed the way to make this collector was using a single length of pipe. I guess you do things different as you say so yourself  Klaus |
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| niall1 Senior Member Joined: 20/11/2008 Location: IrelandPosts: 331 |
Mac i wonder did you ever come across those clip on grooved heating plates that are used on some underfloor heating piping ?...i think theyd make good ready made heat collectors for a panel i inquired about them at a big plumbing/heating store ..the guy basically told me to get lost... making a good heat collector seems the tricky part ...everything else seems to be easily available ..i tried pressing some aluminum plates awhile back but it wasnt easy ...some plates had too big a groove ..some came out ok in the end 
niall |
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GreenD88 Senior Member Joined: 19/05/2009 Location: United StatesPosts: 104 |
If you want efficiency try 1/2" soft copper after making your U bends and such you can take a piece of wood and flatten the copper into a Oval shape, then braze it to an aluminum or copper heat sink. This is what they do in Ice Makers to get the most heat exchange out of a smaller unit. Licensed Master Plumber / EPA 608 Universal License / 410a Safety Certified / Medical Gas Brazer/Installer |
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| MacGyver Guru Joined: 12/05/2009 Location: United StatesPosts: 1329 |
@ niall1 That's a great idea. I had thought of that in the beginning, but I too was at a loss to find the stuff. Twenty plus years ago, someone made an extrusion, which housed the copper tubes 100% and that'd be the best, but alas, apparently those guys are history also. The way I've done it seems to do the trick. I had a 20-gallon FREE hot shower last evening courtesy of my contraption. As a side note, I once went to a factory that manufactured "fin-&-tube" heat exchangers, which were used for baseboard heating with hot water. The way they do that is so simple, it'll make you smile: They take a couple of 4" x 4" pieces of lumber as long as the finned portion of the tube and slice a 1/4" groove with a table saw every place they want a fin along the length of the tube. The boards are fastened to a base with the grooves cut into each board facing each other. Next, they cut out the (square) aluminum fins and punch a hole dead center of each. That hole is slightly greater than the outside diameter of the copper tube. The next step is to place an aluminum fin into each slot and then run the copper tube down the middle of the whole shebang. The tube fits loosly and slides in easily. The final process is to use a hydraulic ram, which has a travel that is a bit greater than the length of the tube and they ram a tapered "plug" down the center of the copper tube. This expands the tube against the aluminum fins so they are stuck tight and that's that! Is that cool or what? @ GreenD88 That thought crossed my mind too, but it seemed too much effort for the hoped-for gain, so I weazled out and did it the easy way. Thanks for the suggestion. . . . . . Mac Nothing difficult is ever easy! Perhaps better stated in the words of Morgan Freeman, "Where there is no struggle, there is no progress!" Copeville, Texas |
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| MacGyver Guru Joined: 12/05/2009 Location: United StatesPosts: 1329 |
Fixing A Problem No project is ever complete without a few little "bugs" and this one is no different. Last evening, as I took my FREE solar shower, I noticed the water was not 110* as measured at the tank, but was, in fact, several degrees cooler; 103*F to be sure. What is happening here is what a plumber calls "cold-water dilution" and it's caused by cold water being introduced into the hot system as heated water is drawn off the receiver (tank). I studied my set-up and saw immediately the problem. When I built this, in my head I "calculated" (read that guessed) the added resistance of the pump impeller and check valve would be enough to resist cold flow through the solar panel when the pump is off and the panel was not gathering heat. I was wrong. Not the first time ever, but maybe the first time today! Anyway, I decided to put a manual valve in the output line between the panel (and ultimately the cold-water source for the panel) to prevent cold water from diluting my precious hot water as it leaves the receiver and heads for my backside as I stand waiting in the shower. Here's a picture you can compare to previous shots to see what I did: 
The valve has a little yellow vertical handle. Doing this will ultimately mean I'll be making water too hot to shower in directly, so I'll have to mix cold against it, which is the "normal" way a shower works. My hope is that this will help someone else build their own solar water heater. No sense reinventing the wheel, eh? (Although I appear to be quite adept at that!). In case anyone's wondering what that "T" fitting is doing hanging in the air, it's there simply because I ran out of couplings and "improvised". Rather than run out and buy a coupling, I had a tee and a cap, so I just cheated!
. . . . . Mac Nothing difficult is ever easy! Perhaps better stated in the words of Morgan Freeman, "Where there is no struggle, there is no progress!" Copeville, Texas |
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mac46 Guru Joined: 07/02/2008 Location: United StatesPosts: 412 |
MacGyer, Is that "Pec's I'm looking at in the picture? "the blue lines", and the copper/brass fittings and valves, is that because of the potiental of high temperatures and so you could'nt or did'nt want to use "CPVC"? I have a water "prewarmer" now, that warms cold well water to ambient temperature before going to the hot water heater. This acts like a air cooler in the summer if we're using alot of hot water. I get some condensation on the copper tubes. Great project! I'm about to stick another "iron in the fire". Is it really that simple, and/or would a storage tank painted black be as efficient? .....Mac46 I'm just a farmer |
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| MacGyver Guru Joined: 12/05/2009 Location: United StatesPosts: 1329 |
Mac46 As for the pipe, yes, it is Pex. The reason I used it is I had to make a six-inch repair in a line on my coach and the supply house I use had it in 100-foot rolls only, so I had to buy an entire roll. With it just sitting around and already paid for ($35) I decided to use it. The "SharkBite" fittings are about $8 or so each, but you'd have to pay someone to help you mess up with them. All you do is line up the pipe and fitting and shove them together and it's a done deal. Only in America! Larry the cable guy would be so proud. As for a cistern exposed to sunlght and painted black, I suppose it would do the same thing as a panel, but the fact that a tank whose side was the same square footage as a solar panel would likely hold 5,000 gallons and if it weren't well insulated on all remaining exposed sides, it'd never even get warm. My little contraption swaps a trickle of water whose total volume is only 20 gallons and it takes all day to raise the temp from an ambient of 65*F to nearly double that come evening. I think if you want a solar-powered domestic water heater, you'd better build just that. Just copy what I've posted here and you can build the panel for under $100. Connect it to any existing insulated water heater and you'll have free hot water forever. You may even be able to scrounge up an existing used panel, but be sure to pressure test it before installing it, because if it were ever to have frozen, it'll likely have leaks. Also, if you build your own, make sure you put a hose bib openable to air both at the top of the panel as well as at the bottom so you can drain it come a freeze. I look forward to seeing your solar water heater post! 
Here's a little plumber's joke: [Quote=Mac46] . . . hot water heater . . . No such thing; who'd want to heat hot water?
. . . . . . Mac Nothing difficult is ever easy! Perhaps better stated in the words of Morgan Freeman, "Where there is no struggle, there is no progress!" Copeville, Texas |
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fillm Guru Joined: 10/02/2007 Location: AustraliaPosts: 730 |
This is a good read HERE if you are thinking about making a solar hot water heater , he shows how to make the aluminium collecters and a crimper to get a tight fit for heat transfer to the copper tube. PhillM ...Oz Wind Engineering..Wind Turbine Kits 500W - 5000W ~ F&P Dual Kits ~ GOE222Blades- Voltage Control Parts ------- Tower kits |
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| niall1 Senior Member Joined: 20/11/2008 Location: IrelandPosts: 331 |
those guys do beautiful work ... they've taken collector forming to a different level ... 
off topic a bit Mac but i found this litle cct a while back .... 
its a simple differential pump controller...might be some use to someone its not to hard to build on vero board ... this should really be in electronics mac ...but seems better tied in here niall |
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| Air Bender Senior Member Joined: 25/01/2011 Location: AustraliaPosts: 206 |
Hi all I like the idea of wraping the aluminium sheet around the copper pipe for better heat transfer. Mac this may not have much to do with your project as it is not thermo-siphoning but an idea i have for better circulation through the collector is to have it set up like a water tube boiler. 
As you can see the tubes that collect the heat are not horizontal as i see on most solar collectors, Having them angled should increase the water circulation, this could be done by angling the copper pipes in the collector or angling the collector itself. Still in the planing stage Dean |
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| MacGyver Guru Joined: 12/05/2009 Location: United StatesPosts: 1329 |
Solar-heated Water Production Update The new model has been on the roof 8 days now and each day at approximately the same time in the afternoon, I've checked the water temperature at the kitchen faucet. Below is a listing of the results: May 22 - 3 hours exposure - "warm" May 23 - cloud cover until noon - 110*F May 24 - off for 2 hrs. in a.m. - 110*F May 25 - ran all day long - 115*F May 26 - cloud cover in a.m. - 114*F May 27 - clear skies all day - 116*F May 28 - overcast most of day - 95*F May 29 - overcast & windy - 105*F Edit: I think I should tell you that my ambient cold water temperature is 65*F. As one would assume, final temperature depends on usage and exposure. When the sunlight is shaded by clouds, the water doesn't get very hot, as one might expect. Whether or not the outside temperature is cold or if the wind is blowing does not seem to make much of a dent in things. I've had one entire week of not having to use my electric back-up water heater and that has saved me a total of approximately 31 KwHr of electricity. That's not much, but it's a savings nonetheless. That's only a cost of around $4.30 but a penny saved is . . . well, you know. In the long run, it'll add up to quite a savings, because my electric bill is divided into "tiers" and depending on the total KwHrs used, the price varies. I've noticed though, that no matter what happens, costs continue to rise so my solar water heater application is if nothing else, a step in the right direction. Up Next: Along about a year ago, I tossed up a post about living a "12-Volt Lifestyle" and I made mention of a 12-volt clothes dryer, which caused a bit of a stir. That's next! For those naysayers from that first post, let me put your minds at ease. I fully intend to cheat. By that, what this will be is an insulated box atop my land yacht, which will create a 3" by 4" serpentine pathway approximately 84 feet long. On each end of the "tunnel" will be a small (here's the 12-volt part) electric fan. One fan will draw air into the thing and the other will push it out. The heated air will then be directed into a permanent enclosure mounted on the wall in the hallway opposite my bathroom door. The enclosure will be equipped with a diverter "valve" if you will, which will direct the flow of dry, warmed air either into and through the enclosure or into my land yacht's interior. Inside the enclosure will be a few coat hooks on which will hang moist garments until they're dry. On cold winter days when I'm not drying laundry, I'll use this thing to pre-heat the air inside my castle and that should help drive down my space heating costs. I don't intend spending more than $100 on this little project and that includes the clothes washer, which I finished today. The clothes washer is nothing but a 5-gallon plastic bucket with a "Gamma" screw-on lid. The opening is about an inch smaller than the normal bucket opening and has O-rings to seal in the water. I tried it out and it still leaks a little bit, but it hangs over my kitchen sink, so the drip doesn't make a mess. Inside the bucket will be a single "paddle" (not installed yet) which lifts the item being washed once a revolution and then dumps it down (by gravity) until it revolves around again. This will force more water through the clothes (I think). Anyway, here are some pics: 
This is the whole thing mounted on a set of 'tapered' rollers I manufactured out of copper pipe and some Delrin (plastic) bushings I made on the lathe. 
These are the two rollers mounted onto a board. They are angled ever so slightly so as to match the bucket's taper. 
This is the opened bucket end with half the Gamma lid jammed on it. 
This is the screw-out portion of the lid with the O-ring in its edge. I haven't used it yet, but as soon as I install the little paddle inside the bucket, I'll wash a shirt or something just to try it out. Never a dull moment around here! Edit: Typo . . . . . Mac Nothing difficult is ever easy! Perhaps better stated in the words of Morgan Freeman, "Where there is no struggle, there is no progress!" Copeville, Texas |
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| Air Bender Senior Member Joined: 25/01/2011 Location: AustraliaPosts: 206 |
Hi Mac The results from your collector are very encouraging. Yesterday I cleared of my work bench which took most of the day and dosnt happen very often. All the best Dean. |
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| grub Senior Member Joined: 27/11/2007 Location: AustraliaPosts: 169 |
There was a series of TV shows from the UK called "Rough Science" and in it the scientists had to create usable things from what could be scrounged. In one the series (set in the US at an old mining camp) they made a 12v washing machine using an electric reversing drill to rotate the wash drum. As the drill rotated the drum a threaded rod moved 2 limit "fingers" that moved the forward/reverse switch on the drill to change the drill's direction. They have also made a small hydro-electric generator and other practical things. I think you, MacGyver, would appreciate their ideas. |
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| MacGyver Guru Joined: 12/05/2009 Location: United StatesPosts: 1329 |
Update For Anyone Building If anyone is attempting to build their own domestic water heater, as I have done, I've discovered that installing a ball valve at the end of the run coming from the output side (hot side) of the collector, enables one to "throttle" the flow down to a mere trickle, increasing the intermittent temperature. The overall daily heat captured is still dependent upon exposure, however, throttling the flow will enable hotter intermittent usage like for a quick hand wash or shave. The reason is, the water stays in the collector longer and gets hotter. As soon as solar-heated water returns to the tank, its heat content dilutes to the internal temperature of the stored water, but the water available for any intermittent usage is drawn from the top (hottest portion) of the tank and it is overall hotter. Make sense? If not, just try it and you'll see what I'm talking about. Installing a throttling valve equates to having warmer water all day long and not having to wait until sunset to use any. . . . . . Mac Nothing difficult is ever easy! Perhaps better stated in the words of Morgan Freeman, "Where there is no struggle, there is no progress!" Copeville, Texas |
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| mac46 Guru Joined: 07/02/2008 Location: United StatesPosts: 412 |
MacGyver, Hello, its me again... I was wondering just how the solar hot water project was panning out. You have'nt really said much about wanting the collector to be bigger or smaller, or any other little adjustments. "other than the throttleing valve," is there any thing you would change given the chance to do it again???? I'm going to make one of these things, but I think I'll need it to be slightly larger. Reason being is because I'll be feeding the 40 gallon tank that all my "preheat" water goes into before going to the 40 gallon gas fired hot water tank. I don't see any reason why it would'nt work, don't want to build it to large or I'll be getting scalding hot water. ....Mac46 I'm just a farmer |
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| MacGyver Guru Joined: 12/05/2009 Location: United StatesPosts: 1329 |
Mac46 Look back one page to the article entitled "Solar-heated Water Production Update " where I've listed the performance. As for any further changes at my end, I think I'm happy with what I've got. I get a free-hot-water shower every night as well as enough to wash a plate or pot or two; my needs are meager. If the sun refuses to shine, I have an electric back-up, so I'm in liky Flynn. As with all solar applications, exposure is key. If you're going to build one, remember this: the sun "can" boil the water. You need to recognize this possibility and deal with it accordingly. Back in the 70's when solar was in its glory days, being a plumber, I often happened upon a "leak" at a water heater that was nothing more than a melted plastic union isolator having been exposed to water way hotter than 212*F. If water is held under pressure, the sky's the limit as far as temperature goes. If you make your collector pannel large enough, it can actually make the water too hot. If you're thinking of adding the solar-heated water close to its end-use point, like dumping it into an existing domestic water heater storage tank, you'll want to install what is called a "tempering" valve. This adds cold water to the solar-heated water so as to let it flow into your house at a temperature no greater than whatever you set it at. It somewhat defeats the purpose of free heat, but it also protects you from cooking yourself in the shower! In summation, if I were you, I'd build it in such a way that you fill a separate receiver and then bleed a portion of that against the inlet of your regular domestic water heater. This will give you more control of the situation and allow you a separate tank from which you can perhaps pull solar-heated water from in the winter to use in a fin-and-tube space heater. Doing this will lessen the amount of "heating" fuel you'll use in the colder months. Hope this helps you out. . . . . . Mac Nothing difficult is ever easy! Perhaps better stated in the words of Morgan Freeman, "Where there is no struggle, there is no progress!" Copeville, Texas |
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Greenbelt Guru Joined: 11/01/2009 Location: United StatesPosts: 566 |
MacGyver, Hi Mac. A very good post and something to include in any plans a Fella my have. I have a Question, For your Fans out there, Can You estimate How much larger your collector would need to be to provide a bath for spouse and 3 children, With your California Sun Constant?. We Northern people can add 20%. I'll drink to the free hot bath. Cheers-----Roe Time has proven that I am blind to the Obvious, some of the above may be True? |
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