Of course, there are so many ways we can do that, where do we even begin...greywater, building materials, passive solar climate control… I think for every modern convenience that bleeds our wallets dry and consumes resources like a black hole, somewhere out there, there’s a solution that’s within our reach, that won’t cost us an arm and a leg.
hot water isn’t a necessity to some folks, but for me, I really, really want hot water on demand. I know, I’m ridiculous, but I just don’t think I can personally find the hours in a day to heat a massive pot of water every time I need some.
That’s why this product really stood out to me - I’ve heard of rigging up rocket hot water heaters, and of course propane heated tanks, but the idea of a solar heated hot water tank has honestly just not occurred to me as an option.
I stumbled across this product while doing a bit of research the other day though, and I’m anxious to download it and give it a try.
These solar water heater plans include 90 pages of detailed plans, with diagrams and materials lists, that will show you how to build this system from start to finish. It’s not too crazy technical either - even someone like me, with very little plumbing and building experience, is supposed to be able to put it together in a few days.
Here's the product thread for this ebook
Here are a few bullet points on this guide:
It all sounds sort of gimmicky and too good to be true, but I can’t help but think there’s some legitimacy to these claims. I know that solar heaters are hugely successful, and solar ovens are as well, so I’m wondering, hey, why not - why wouldn’t this work?
Has anyone ever installed a solar water heater like this? How did it work out for you? I’m thinking about purchasing these plans in the next week or so - they’re available for instant digital download, and curiosity is definitely killing the cat over here.
I can’t picture my life without a water heater, but I also can’t imagine building a beautiful, off the grid sustainable home with a big hulking energy-suck like a water heater in it. This seems like kiiiind of a perfect solution.
We wash diapers every other day in this house - hot water is crucial to the process.
Learn how to build a solar water heater and cut your electric bill - you can buy the plans here.
EZ-37 Solar Water Heater Panel
People would be amazed at just how simple the system is. Yes, you can build one in a few days and yes it will work. I'd look to more than solar as the heat source though; wood has a much faster recovery time, and works when clouds are present.
Note that if you use a wood heat source, that stove can only be fired up if water is in the lines. The format for the wood stove includes a coil to absorb heat, and if it contains no water, it will burn through.
Here's a video that shows what you'd be building.
John Weiland wrote:Great that your diagram has a by-pass valve for winter as the collector will definitely need to be drained and by-passed during those months.
I agree, that was my main concern too. I live in central Montana, and it's reassuring to know there's a solution to climates that stay below freezing 6 months out of the year!
Chris Wells wrote:The image on the front is a simple thermosyphon system. I've seen some built using solar collectors to heat the water, while others have used wood furnaces. I have not seen but think it possible to build a version that contains both heat sources.
That's a really good point - I live in a valley where winter days get seriously short, maybe 6 hours of sunlight, and I can see where there definitely wouldn't be enough sunlight many weeks with bad weather. The idea of combing designs for those of us up north sounds perfect, thank you so much for sharing!
So it sounds like you would just need to create some kind of hybrid design - I think this would mean doing away with the water tank heat source (electric/propane) entirely and replacing it with the wood heating system, correct? (Sorry if that answer is in the video, my kiddo is finally asleep and I dare not play any audio at the moment).
A new, modern high performance collector runs $800-$1000
The glass has a replacement value of about $300, have upwards of 15 percent more light transmission and is tougher than the doorwall glass replacements that i totally use for diy collectors and coldframes. (Two pieces of glass 34"x72", free on salvage, $40 new for just the double pane assembly, and you can cut them apart to get 2 sheets.)
The absorbers are usually copper or aluminum of proper arrangement and thickness. They will have a selective surface coating and headers that allow stacking in parallel and series. I look for parallel risers instead of serpentine waterways so that design can accomodate thermosyphon or drainback. I like drainback because you can use pv direct pumps and controls for infinite c.o.p. and can have nearly indestructable distilled water as a heat transfer fluid while maintaining utter freeze protection.
Good collectors should preferably have extruded aluminum frames with mounting slots or clamping flanges on four sides.
Insulation can deteriorate if not supported well by the manufacturer and especially with stagnated air heaters. Its a cheap fix and they are back in for 40 more years.
These are available in all kinds of makes and configurations, dual heat exchangers, one for input, one for output or other.
I like vats. There is a wine vessel, stainless, 10ga. All kinds of sizes, 200 gallon for $600. They come with a lid that fits inside and expands to retain. This allows you to keep evaporative losses low while being able to adjust volume for diy testing, and change of demands. Additionally its easy to add input and output coils, and boiler or other source feed and return of storage water.
The device that heats our water is a poly barrel with a screw on lid.
I put a copper coil in contact on the outside back of our pedestal wood heater. A pv charged battery system powers the circulator and differential thermostat. The thermal storage water circulates to the stove and back like a fountain. The potable water is a paralell set of coils 125' each, 1/2" pex, immersed in the vat. Recovery is slow, but it works great for two showers, a set of dishes and all day hand washing during the heating season.
When the stove is being cooked on, or heating space, the operation is automatic. As soon as the stove is up to operating temp the circ pump kicks on, so all that is required is ignition and fueling the woodstove on demand.
This is installed along with a solar thermal side that is half finished. A single 4'x12' collector that we salvaged well, is mounted atop my roof and just needs plumbed.
We are on season four without issues other than improper exchanger sizing, but it is close enough for daily use! Just slow recovery by gas or electric standards but it rarely hits high limit and is safe. It gets hot enough to eliminate legionella and keeps storage/boiler water un-mixed with potable water, soon to be a standard worldwide. Food grade h2o can be used but is not required as a treatment in order to ensure safety before servicing. I just run it hot!
With this setup, we are cooking food, heating space, drying clothes and heating domestic hot water for half the year, all from our locally available resource, strictly dead timber.
Solar thermal gets low respect. Its not blinky or noisy enough, go for it anyway!
The wayback days!
Yes,....I am cringing as I read this. When we moved to the rural place we have been camped for the past 25 years, there was a stack of these with smashed plexi-glass coverings over in a corral.....the goats had been bouncing up and down on them! :-/ First thing was to remove the broken plexiglass which went to the land fill. Then the collectors sat there in the corral for about 6-7 more years.....then I brought them to the local junkyard for scrap metal. As you said, they had all of that copper tubing wending its way through a black anodized-looking coated surface. There was at least 3 collectors, each about 3 ft X 8-10 ft long.
You mentioned the 'way-back days'.....didn't they have the 'way-back machine' on Rocky and Bullwinkle? I could go back in time and save those collectors for a new life!....
There have been more, but i have turned other people on to them.
We once pulled a 4'x20' foot pool heating collector from the side of the road on trash day. It was a heater for an outdoor shower from april to october and had several inncarnations. We circulated it with pv and an rv diaphram pump, but they will thermosyphon. It would bring 48 gallons to 150°f., by noon-thirty or so depending on conditions. They have no cover.
Dont believe the tripe about 'yeah but if there is ever anything but 70 degree weather, they are useless and you must use evacuated tubes'
I dont know how many systems will never be installed because of that misunderstanding. Evacuated tubes have plenty of performance edge, but in my case below zero degree weather is no bar to operation and simply does not invalidate their usefulness and value.
We have watched 150 degree fluid temps circulate during strings overcast days, in february at 20 deg., though with evacuated tubes. Flat plates can still hit 250-300 degrees, stagnating and just under that for low efficiency, high temp operation, just not at extreme delta-T., ambient versus collector temp.
Even during poor production, flat plates can pre-heat incoming water to a much better temp than ground temp in winter. This 'useless production adds up to way less fuel usage or way more utility than to not have it in place and usually a well designed system will provide 50-75 percent or more reduction in fuel use. The fueled heater is backup for solar shortfalls, not the other way around.
Many households will only require a single collector to attain this offset.
The guy i worked for when i was younger, had a salvage yard of all kinds of collectors and absorbers, stacks of them organized by type and maker.
These things produce 10's of millions of btu per year and are precious.
Borosilicate or water white, iron free, pyrex, it goes by all kinds of names, but if you want a family heirloom, look for glass covers, aluminum frames, stainless screws, selective surface coatings (metals not paints), copper absorbers, unions, and a metal backing sheet for survivability and support of the insulation back sheet. If it does not have all these feaatures, it is not a show stopper! The details are just the mark of a high performanc collector. Specs and name plates may be faded or otherwise missing, so researching what you have can be hard unless it has a nicely embossed metal tag riveted on, another good sign.
This is one of my favorite things ever! They are hand made at Maine by a guy named...Guy Marsden
It is a differential thermostat that will accept pv direct or battery power, is built solid, servicable and inexpensive. Does not have a touch screen with an ip address, but thats the point.
We built all kinds of systems with no controller at all. The pv panel is sized to operate at 80% or better scavenging efficiency if done right. Performance is improved with automated temperature based control.
On pv direct with the art tec, your circulator can still modulate a little but it is not precise. Good enough it starts and stops at appropriate conditions.
Love to share these and hear what people are doing.
frank li wrote:It is a differential thermostat that will accept pv direct or battery power, is built solid, servicable and inexpensive. Does not have a touch screen with an ip address, but thats the point.
This made me laugh! I feel like the basic concept of a solar water heater is pretty simple, but you can get really technical with it really fast - keeping electronic components out of the picture as much as possible makes me feel a little better about our abilities to service and repair it over the years!
Another reason my husband likes older cars Less technical, more maintenance friendly.
What I am doing will be a 12' x 14' collector surface (because that's how much south wall space there will be on the master bedroom addition), nearly vertical to minimize midsummer overheating and maximize winter collection, with a 3-400 gallon storage tank in the basement just below the bottom of the collector so it will drain back completely. I get frequent days in winter with no direct sun, but a cold sunny day will make my house comfy warm without added heat while the sun is shining. The collector to save up some of that for the nights should reduce the heat requirements significantly much of the year and give all the hot water I want in spring, summer and fall.