There's another video out there - Wilderness camp/research center up north by a lake, they build a giant compost pile the first week of the season, and bury 150 feet of garden hose in it. They use it to make a hot shower from the cold lake water. Within the first week, the water is too hot to use by itself - it is scalding at 160 degrees or so. By the end of the summer, the water is still warm. So many ways to get things done in life...
@@nate5520 Sorry couldn't find just what I was thinking of, but there are various videos if you search compost and hot shower. The main thing is to run 100 feet or so a tube/hose through the pile, and build the pile as big as possible. When it first heats up, the water will be scalding hot.
I taught a few lessons on solar energy in a basic Physical Science class back in the late 70s. I student worked with his father to build something very similar to this. He had electrically operated valves and temperature sensor. When the water reached a certain (HOT) temperature the valves would open and the water line would force the hot water out. When the cold water reached the temp sensor the valves would close and it would start to heat the water again.
I was thinking of doing something similar except to preheat the water going to the water heater. Would it be advisable to place this inline before the water hearer and use the radiant heat of the attic to preheat the water going into the water heater? Have it set up to run during spring, summer and fall and bypass during winter to avoid freezing issues.
@@thomasm0481 your attic should still be warmer than most places of your house in winter--and that would certainly still be a better place for the pipes than under the house. ...but you're going to want to make CERTAIN that you never spring a leak up there.
I made one of those in 1983 with a coil of garden hose on a piece of corrugated roofing painted black. It was a simple ecology conservation project at summer camp to see if we could inexpensively harness the power of the sun. Surprisingly, it worked!
@@jimato01 если не трудно, подскажите, является ли используемая в нагревателе труба устойчивой к ультрафиолетовому излучению? Насколько я понял, это труба из сшитого полиэтилена, которую используют в системах напольного подогрева при строительстве. Насколько хватит ресурса трубы?
I love how you show the “after” before showing the build. Most videos show the build first and I’m never sure what I’m looking at. Excellent technique!
hi and thank you for the feedback. i figure people want to see what i actually did (and that i actually finished the project). i often see videos where people start building something but then they never finish the build. their video just ends with no finished project.
I love the simplicity of this, I would cover the inside of the whole base with a thin layer of aluminium or steel sheet. This would help heating up & with your enclosure the thin metal sheet would hold heat for longer. This design gives me ideas for making 3 or 4 of these hung on the side of a house, giving an increased simple water hearing system. I have to say VERY well done, I shall have to go and wash the green with envy off my face though.:)
Should paint the pex pipe portions that extend just out of the box too to give them UV protection equal to inside the box and bag some extra rays too. Great build- very nicely done. I love it.
The solar hot water heater started out in the USA in California with a coil of high temp. poly pipe on the roof. It continues to morph into new and interesting designs. Yours is lovely and compact. Thanks for sharing.
A friend of mine built basically a similar setup, but on a larger scale. He used 1.5" PVC tubing suspended on T-posts in a coil shape like what a spring looks like. He had two sections of sheetmetal that were 3 x 5 ft on the bottom and one side forming an L. He had ball valves and y fittings and painted everything black. He had it plumbed in line after the filter for his swimming pool to heat his pool. It would literally raise his pool water temp by almost 15° in 30 minutes.
That sounds great; I’m thinking of in line application using pool pump and guessing the current video setup would cause too much flow resistance. Any links to your friend’s setup or further info on build?
Best i've seen, just a heads up to anyone, solar panels have spacing for maximum surface area and coverage from moving light source. Space between hose coils would help that.
mm... me too, but its not free.. the sun's doing all the work.... I know free to us... but most people dont understand why there is no such thing as free energy.. the 2 laws say that.. you cant create energy and you cant destroy it... means you can only concert it from one thing to another.. aint free to the sun.. its burning of massive amount of hydrogen.. lol
I really like the notion of using freeze-resistant pex over copper tubing (for non-potable bathing water). But copper has a huge advantage: it can be soldered into a horizontal ladder for the angled plate collector whereas pex is most easily coiled. And the problem with a coiled layout is vapor lock. Gases readily fall from suspension as water heats, which create bubbles that rise to the top of the coil loops and stop the thermosiphon flow. Unless you're actively pushing pressurized water through the pipes ... no bueno.
@@VividDroid I've never seen 1/4"-1/2" in a coil. Basically only propane lines. Besides, you can put 90° sharkbite fittings on pex, no soldering required.
For a broader application, don't think of it as just supplying heated, potable water. Close the system and circulate water that has antifreeze in it. Use that heated solution to warm large heat sinks such as concrete slabs or block walls to store that daytime heat. The heat sinks heat rooms throughout the night. You can also direct forced air over the heat sinks or though heated radiators to heat rooms in a more controllable manner.
Yes. Radiant floor heating for an RV is what I'm thinking.
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Water tanks are better sinks for the heat carried by the antifreeze. Water has the best heat capacity. I plan to store 200-500l of warm water for underfloor heating the home and bathing and general warm water usage like dish washing and laundry. Big insulated drums with two or three exchane coils per drum. It's a bit more complicated, it implies a few pumps and a few antifreeze circuits, sensors and failsafe measures but it is doable diy stile.
@@erichawkins3915 Pex may be able to handle freeze/thaw. Typically, some of the fittings, valves, sensors, pumps, etc, will not be freeze-proof. I'm not aware of a more practical antifreeze than glycol.
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@@erichawkins3915 it will fail after a few freezes. PE is plastic, not very elastic. It will expand more snd more with every freeze until it gives.
Great work! Put before the hot water tank would be perfect. Tank heater would come on much less (save $$$) + hot water supply would be consistent. Great idea!
Thats what I was thinking. Maybe Use some big 2" galvinized with a 1/2" out. The metal might add some heat retention to heat the incoming cold water? Might save a couple hundred a year..
Your 30" x 30" box is about 0.6 square metres. On a good day you may capture about 4 kWh/sqm. So you will get about 2.3 kWh of heating out of that setup. That's enough to heat 33 litres of water from 20 C to 80 C. Useful. Like six of those will heat a 200 litre (44 gal) drum up 60 degrees C (160F) over the day, and that can then be used for heating the house, releasing an average of 2000 watts over a period of about 7 hours. That becomes quite useful as space heating (of course it performs best in the summer, when you want cooling, but never mind). Small solar powered pump as a circulator. Set the panels up in parallel to heat the drum isothermally (i.e. avoid the temptation to maximise heat rise per pass thru the loop). Nice.
Nice job!! Thank you - have a 20 year old copper based system - - its breaking down - from not draining it properly before winter 😉 - going to ditch all the copper and use your approach - I’m fired up!
Great video. When I wanted to shower, in Vietnam, I filled a plastic 5 gallon water can and set it about a foot from our 3KW generator. About 45 minutes later, it was the perfect temp to pour into the Australian shower bag....5 gallons is enough, if you shut it off after your get wet.
I built one like this years ago for my nephews science project. He won. I used foam board insulation on the bottom and sides to help hold in the heat. We had water at boiling temperatures depending on flow rate.
These DIY projects only ever show temperatures as soon as water starts running. What is the % gain after running for a few hours, once the water isnt sitting still in pipe and the pipe has cooled down due to water flow.
The company I work for makes solar panels for water heating. I recommend using “solar glass” which is a low iron tempered glass for use in solar panels. You will get more heat gain by using this type of glass. Overall you have a very nice build and are off to a good start. If you want to avoid overheating in summer and freezing in winter you can build this with a “drain back” system.
I did a heater very similar. It was 4x8 in size. Ran off of a 1/3 hp submersible sump pump. Heated a pool 35 foot above ground brought all that water up bu 5degrees. Worked great. I also covered mine with plexiglass to give it a greenhouse effect.
I followed your method today to build one only did a 4x4 and 300 feet of pex. Need to paint and all still but it seemed to go together well. Thanks for the video.... hope it works
I wanted to say thanks for the video as it inspired me to make my own using the wood scraps I had left over from other projects. My one hang up was getting a piece of glass/plexiglass cheap. I found my answer at Goodwill - I bought a larger framed artwork and used the frame and the plexiglass for the lid of my box made to fit the 42.5" x 36" frame. It fit about 150' of 5/8" tubing . The water to the pool is 96 degrees.
that's great! - i often tell people to build the collector 'around' the piece of glass they can get. it's great you were able to use leftover wood scraps.
In my northern climate I have been using the same system in the summer, to raise the temperature of my above ground swimming pool by a few degrees. A 50 foot coil of 1" Corlon wound on a 4x8 sheet of Plywood, painted black with a stapled on sheet of transparent vinyl as a cover. Water is fed by a tap on my water filter pump. When the sun is out I simply shut the valve to the system. The thing sits at the back of my yard and I sunk the pipes 2" under the grass, it gets some more heat from there too and I can mow the lawn no problem. Good from the middle of June till nearly the end of August in my neck of the woods (Vermont). This gives me an appreciable amount of free heat for my pool.
I just completed this project today. FYI I used 100 ft of 1/2 inch plex. It's not as hot as the 300 ft 1/4 inch coiled on a cross solar heater i made but the flow rate is way faster and I also didn't use plexi-glass (way too expensive right now due to Covid). I'm gonna rework the other one in the same style and link all 4 together. 12ft Pool/Hot tub coming up!!
Nicely done. I think the overall lifetime of this system would be limited by the life of the wooden enclosure not the pex or shark bite fittings. Here in Houston I doubt it would last longer than a single season. You might be able to improve it by using reflective metal like flashing for the inside back of the box and suspend the tubing a small amount above the back wall. That way the entire surface area of the tubing is used to capture energy.
With the wood being primed & assuming it's not treated wood, it would definitely last atleast a few years before it starts to deteriorate. The primer alone adds a significant amount of protection from the elements.
@@jeramychunn9108 I was thinking the treated stuff would last longer? Isn't it meant for outdoor conditions. I'm in Ireland so water getting into the box would be a factor. I'm sure priming it first as you say would stretch the life of it. We use black hyrdodare piping here for potable water - 3/4 inch or bigger. It's also meant for outdoors and comes in a 25m roll, it might be ideal for this. Not sure about the amount of heat transfer that would happen but it's worth a shot
Awesome simple design. Did something similar long ago using copper, yours is much much easier. Might consider insulating the outside of the back board and sides & adding another layer or 2 of PEX. Double or triple your capacity without much more effort. Great job, thanks for making this video
If you wanted to in that Center space you could take something that is circular especially if it's made out of aluminum or stainless or basically any metal but plastic would work too and put that in the very center and take one section take put a break in it but your connections and install that tank if you will inline to give you more capacity cuz I think two gallons is way too small especially for the size of that box and everything else how much work goes into it you can even reduce some of the pics link this inside the box to install an even larger tank that would be flat but Square circular that would fit within that sitter space of the loops that you removed
We did a simple thing like this. Just because we had an opportunity to hide our septic pumps and the roof space and orientation lent itself well to preheat water before it enters our water heater tank. We’ll build a bigger and better system for our hot water needs as a whole eventually. We’ll probably still run it thru the water heater tank for storage and consistency. Ours really only turns on at night if we use the water up. During a hot day, it will never come on. I think using these types of energy hacks are excellent methods of conservation.
The black paint protects the sensitive PEX from UV (which would quickly degrade it). Pretty Smart dude... Best DIY jobbie I have seen. Anybody could build that. Light Weight Low Cost Simple DIY
I have looked at these kind of things for decades. This is a simple design. Whatever output this produces IF you put under it a piece of alumium flashing your heat will increase. If you take flat black priner and Spray paint the Aluminum and the hose your output will greatly increase, it will be almost boiling. IF you take Plexiglass and the screw that on time of the painted stuff you will reach the marximum output. NOW if instead of Plastic you use a copper coil doing the above things you can get a parabolic mirror and shine it on the copper and metal and the water will reach boiling point. The Idea here is to have a tank that would allow the high pressure heated side to push into a tank and to have a check valve on the low side so the cooler water could only enter your tubing creating a natural siphoning action to circulate the hot water. In Very Old Houses they had a water tank in the attic that was the domestic hot water for the summer. Cheers.. .
I like your idea of using the copper pipe, but also use a metal box that can take a lot of external heat., so you can put a fire pan under it for a heat source on overcast days or at night.
Built two of these 4 years ago for my above ground pool. 4’x4’ each. Mounted on my pool deck directly facing the sun. The plastic pipe lasts a long time the wooden component are showing signs of damage. Although water exiting the unit after it has been shut off for a bit is very hot , too hot to touch, this type of unit does not sustain a constant high temperature. After a couple of minutes the output temperature will be only 4 or 5 degrees warmer than the pool water. Considering the pool has several thousand gallons of water, I’m not convinced the pool temp increases a significant amount. I will be moving my collectors to my shed roof in hopes contact with the roofing shingles will add more heat to the pipes. Also be sure to stop the water flow through the collector at night to when cooler water will be pumped back to the pool.
I would think two 4x4 panels really might not make that much of a dent temp wise William when you consider # of gallons in the pool, constant cooling due to evaporation, heat loss due to conduction, etc. Maybe a good solar pool blanket would help if you keep the pool covered when you are not using it. Amazon has temperature controlled relays for fairly cheap to keep the system on only when the panel temp is high enough. Beyond that, more panels. Good luck amigo.
@@sempertard I hear ya The solar covers really aren’t made to use to heat the pool. Their function is to insulated the pool especially at night when the air temp drops below the pool temp , minimizing heat loss from the pool. Although using a solar cover will reduce evaporation of water and your chlorine, it will insulate the pool and trap the cold water in the pool. It’s best to let the sun shine directly into the pool.
@@williamsrmonroe8406 As a longtime inground pool user in Texas I can say your info about solar covers is mostly wrong. Your statement about using the cover at night (to deter evaporation which retains warmth) is correct, but when the sun beams the cover becomes a very effective heat source that is transmitted directly into the water. My results are 4 to 6 degrees + in a day's time. At night the water tends to return to the temp of the earth beneath/surrounding the pool.
Was very sceptical at first. Then was pleasantly surprised. Hooked up easy. Took two days and wow the temperature change was just awesome. So we ordered again and now the pool stays around 30c.
Nice project... Here in my house in Brazil, I use a 1/2 inch irrigation pipe and I put a system with arduino to control the water temperature by sensor and turn on a 12 volt pump connected to a solar energy board to move the water. In summer the water temperature reaches 65 degrees Celsius.
Hi from Sunny South Africa, can you explain your system, I am now actually testing with sonoff wifi switches and temp probes each on inlet(Cold water) and another outlet (heated water). If the preset temp in the outlet is sensored to the preset temperature, it starts the 12VDC pump to push the water into the feeder tank which is connected to the 150l geyser as preheated water to get the best efficiency and pay less utility bills. the feeder tank hold enough water(around 200l which means the system must produce 400 litres a day.
Adding an insulative backing behind the tubes could decrease heat loss by conduction into the wood panel making your system more efficient (hotter output). OSB already has a pretty low thermal conductivity, but most insulation has thermal conductivity an order of magnitude lower.
@@donnyh3497 This is how vacuum tubes work in solar heaters. Anyways replacing air with CO2 or a better greenhouse gas might further increase its efficiency,
@@johnzach2057 Air is actually a really good insulator, co2 counter intuitively would decrease the efficiency because it absorbs the heat and radiate it back out of the panel.
Very interesting build. I tried to make a passive batch water heater our of a water heater tank painted flat black. Given the free cost it worked out well for the weekend cabin.
I built one just like yours in 1972 using copper coil from a hardware store and salvaged tempered glass from a demolition site and of course built the wooden box. I also added a standard water heater pressure relief valve on the outlet. Worked great. That new pipe should make it cheaper. Good luck.
The pretty chrome trim on the shark bite valves are also a removal tool for taking off the valve if need be. Just turn it around and slide up against plastic protruding from valve and press in. Should then slide off of the tubing.
If you would like the temp to hold hours after the sun goes down pour some black sand on to some spray adhesive the silcate will keep the temp up hours after the sun goes down.
Can you make a video of how to attach it to the hot water tank so that we can mix it with the cold water tap? Not only is this a great idea but you do a clean and efficient construction. Makes learning so much easier.
Just disconnect the pipe that feeds your water heater and run a pipe up to your roof, tie it in, and another pipe to bring the water down to then tie into your water heater. I made one with a bypass and drain downs for the winter. Be sure to use an expansion tank ! I did not penetrate the roof but came out the side just under the eaves
You are going to want to install a Thermostatic Mixing Valve after the water tank to prevent scalding. It mixes cold water into the hot water to your desired temp amzn.to/3wHjZYu
When you say mix it or add it in line to your cold water tap are you speaking about the line that would come to your fixtures for cold water cuz if so then don't connect it to that if you're talking about the line that feeds in the tap water into the hot water heater that comes out hot then that would be okay but you always want to have the cold water at a much lower temperature than the temp of the hot so you have some way to balance
Installing space between each wrap of the coil will increase the surface area being hit by the sun and increase your heat output. Another way to look at Less of it will be in the shade. I have done this and after my first attempt, I realized my flaw and leaving a gap is an additional 25% more BTUs. Your design is very neat and tidy.
msears101 how much space between wraps did you use in your design? Your recommendation adds to the success of the build. After more than 9 days of no power in last years hurricane, it would have been nice to have this as part of my backup up kit.
I just bought all the parts to make this. I will report back on how effective it is. I have a pool I want to heat up and was going to hook this up to the circulator.
I'm in arizona where its sunny 363 days a year. I just throw the old garden hose out in the sun for about 30 seconds and turn on the water. The length of your hose is directly proportional to the quality of your warm (if not hot) water needs.
Take care. Different hoses are made with different materials some of which are toxic. I've pondered whether you could use safe white RV hoses used for potable water and paint them black. There might be dark colored potable water hoses already available
I must say this is impressive. Couple of improvements on materials though. Buy the PEX in "Black" and then replace the glass with "Cell Cast Acrylic". The cell cast blocks 95% of the UV rays and is much more durable and you can cut it yourself. Google my suggestions and you will see I speak the truth. All the credit of this project goes to you my friend!
The only way you'll get that up to 135° is to let it soak in the Sun. After the standing water from the tubing is depleted the temperature will drop drastically. Made something very similar years ago, but I used to holding tank. But the cold water thermosiphon through the coil to the top of the tank for storage and then fed my tankless coil on my oil boiler. On a continuous run in the Sun you would be pressed to gain more than 10 degrees from start to finish.
There are so many naysayers! This is way cool! And with your ingenuity you’ll be able to do a lot with this. When I can find the time I think I will Make one myself. Thanks for sharing!
Nice looking job! Questions: 1) What Pex hose diameter did you use? 2) On a sunny day at about 50 degrees F, how long does it take to heat ground water to about 140 degrees? Thank you.
Would be nice to see all the temperatures and flow rate to see how constant the temperature would be. What was the inlet temp of the water? What was the outside temperature? Great design for sure.
I love the idea of solar water heater! With the use of tank booster mixing valve to not make it too hot and increase usable capacity, I think this could work. Is there any danger of overpressure when sitting in the hot sun when water is not actively running and therefore, do I need a pressure relief valve? I'm thinking about putting this behind my electric tankless water heater so that it doesn't have to work as hard during a sunny day and save on utility bills.
Back in the 80's, I had a married neighbor couple that were ex-hippies. They bought a small school bus to convert into a motor home to do some traveling. I helped them build a solar hot water heater just like this that they could mount atop their bus after parking it. No such thing as PEX back then, but polypropylene irrigation tubing was cheap - and I used two coils - 200 feet - of it and built a double box arrangement just like the one here. They loved it. Now I am tempted to do it again using PEX and shark-bite fittings. I would also add some aluminum sheeting to go under the hoses - and paint everything flat black, then used acrylic or poly-carbonate for the window - not glass.
I note that PEX is available in Blue....which you may find absorbs heat from the sun a good bit better....I painted the deck of my schooner a very light sky blue before going to the tropics....and once there had to repaint in tan. The blue deck had to be sluiced down with a bucket of water before you could walk on it...the tan was warm but never too hot to walk on....good luck with your projects! -Veteran '66-68
@@doughesson Yeah, buy a kettle. This contraption will do nothing but give you about a gallon, if that, of hot water. Once the water is replaced in the coil with cold it will need to sit and heat up before more hot water can be extracted.
At just under 2 gls. & 140+°, adding just enough cold water to make it compfy do a camping shower. ,1. Adjust flow & temp 2 get in shower wet down 3.water off 4. Soap up 5.water on 6 rinse n dry No biggie and this is a great design. I'm making one for my country hut.
Very good , going with nature is definitely the way forward . Solar thermal is certainly under used and when it is too much tech is involved to increase cost and maintenance
Great build and very informative. The only issue I have is my OCD kicked in with the last innermost part of the pex not going under the dowel. Did that bother anyone else?
Hi guys, just wanted to let you guys know I actually built one of these today following the specs that he gave, so I used roughly 90 feet of PEX. To me the hottest part was getting it to sit flat inside the box when you were winding it around, he made it look very easy when he was doing it but in fact it was very complicated and difficult but I did get it with a couple of hands helping me and I had the sun hitting it for about a half an hour and the temperature spiked up from 75 degrees to 110
This is pretty great, it would be an awesome setup for a camping shower or for a passive heater on the roof of a house, hot water is circulated from the roof heater down through a super insulated very large storage tank during the day heating the water in the tank to possibly 160F+, then at night the circulator pump stops and you have this huge tank of hot water for showers in the am or running the dishwasher, etc for virtually minimal cost, no fossil fuels. Consider making future boxes larger from 1x6" poplar(added room for insulation, see below) and plenty strong with much less weight. Several hundred feet of 1/2" copper tubing will allow more heat to transfer into the water faster as copper is so thermally conductive. Insulate the box back and sides with ridged foam board. Have a standoff for the tubing so there is hot air behind the copper tubing in In front> increased heat transfer into the water which will give hotter water or more gallons of lower temp water.
In a concrete roof in Cali, Colombia laid down 6" of Styrofoam with bar on top. Attached 100' of pex. Imported Sharkbite to Colombia. Attached concrete on top. Nice hot shower and kept the room cooler. Got to 120F by 11:00 AM. Used electric shower head, when cold. Only use CPVC!
I see this as a way to pre-heat water for a smaller 8kW on-demand water heater. The lower power units will work with good flow if they don't have to raise the temperature from 50F to 105F. If you're starting with water preheated to, say, 95F, then you can shower full blast!
Your right about painting it. It will last if you keep those UV rays off the pipe. PEX is sunlight resistant for about 30 days will break down fast in direct light. You might want to paint or cover those ends where your valve is and the connection side too or your solar heater pipe WILL break there. Good project, thanx for the idea.
It can last, hot and cold doesnt effect it. The pipe is freeze/thaw stable its the UV from the sun. Take that pipe you have now thats been outside, if its been subject to direct sunlight, bend or flex it back and forth you will see perfect broken circles in the pipe. Keep UV off and it will almost last forever...
That is an efficient use of the pex if it's portable & can take it inside when outside temps are below freezing. I built a heater out of pex too but since its mounted permanently outside, I had to make many horizontal loops at a slight downward angle with a drain cock at the bottom to let it drain out if it freezes. Has less pipe per sq ft than yours but more practical in a permanent situation. I use a thermal sensor switch to turn on a circulating pump to store the hot water in a regular tank water heater & get scalding hot water all summer & working on a bigger collector now to do the same for winter.
Built 2 lined the inner sidewalls with foil for a little extra heat..mounted them on top of my xterra and now I have a gravity shower and a hot water supply for my built in kitchen sink for my cooking station mounted on the back...fishing and camping on the beach in the OBX here I come...
What a fantastic Solar Project! Thank you for sharing this... 140 degrees is the same as a regular household Water Heater...perfect. This is such a better idea, than using a plastic barrel, painted black... Lighter, portable, and more efficient!
Awesome idea! Thanks for sharing this. It also gives me an idea: I once built a large aquarium (for frog breeding) out of plywood. You heavily "paint" the inside of the plywood box with epoxy. I had it for years (indoors), and it remained water tight the entire time. If you did something like that here, you could put a simple valve in the side, and evacuate the space with a vacuum pump, which would, I think, greatly increase the efficiency. Thanks again for giving a great example as it is, and for providing food for thought for changes. I want to make one of these for a four season, cold winter, greenhouse (with water barrel heatsinks).
Theres a vid on yt about a guy that put something similar in his driveway... It was not impressive... I believe green bay packers have a heated field... Dunno how well it works but ive read its only good in a narrow range of temps/snow volumes.. ??
Just as an FYI, whenever mixing plastic and metal, always try to make it so the plastic goes inside the metal fitting, as metal is much stronger. If you put metal into plastic sometimes you can crack the plastic.
This design is almost perfect, and is something I have been considering for a long time. I would just add two things. One, a thin layer of foam insulation behind the pipe to stop heat loss out the back. Two, I would add a solar powered water pump. When the sun comes up, the water and heat start to flow. When the sun goes down, everything shuts off. Have you given any thought to adding those features?
Brilliant video, really thank you. Can anyone tell me if it's more efficient to also paint the window/glass black also! I've seen designs painted and designs clear like this.. just wondering if it's down to preference or if one is the better option..
Good stuff! I wonder if you could put one-way radiant film on the glass (with passing side facing outward allowing light in, and the reflective coating on the inside) to help trap even more heat within? I know thermodynamics won't allow it to completely hold on to all of that radiant energy, but it might be able to drive the temps up slightly higher? Just a thought.
After seeing so many comments about people wanting to daisy chain several of these boxes together or how to get more capacity I just want to say that you don't have to use that thickness of PEX pipe you can use other plastic hoses in piping that is available online and at some of your hardware stores so if you were to go from say 1/2 inch inside diameter to 2 inch inside diameter hose you would have effectively increase your capacity Eightfold
I would like you to elaborate, what was the outdoor temperature when you did this test, also I would like to see a winter application where it's cold outside on a sunny day and see what kind of temperatures you get, very nice build.
@@FixNewsPlease yes 100' of 1/2" PEX would hold only a gallon of water so basically only 1 gallon of hot then slightly warm. Need something metal to transfer heat but definitely this is cool idea especially if used with temperature mixer to combine hot and cold then could definitely use as very fast shower.
@@clintg3435 you’d want it attached to a tank, not just a hose like the demo. It will even circulate without a pump if a tap at the bottom of the tank enters the heat collector and the hot water out reenters at the top of the tank, provided that the heat collector is not positioned higher than the water level.
@@Goodwalker720 I've seen something like that for flame generated head where the heat causes the water to circulate but not with solar. I would assume the same properties would apply. THanks.
No need to close loop it, thats as outdated as are unvented pressure cylinders, use a Thermal Store, which can provide heating as well as potable hot water.
Three years ago i mare two of these to help warm my aquaponics system. It certainly did help increasing water temperature. Yet I would not build it like this again. The friction I. The length of pipe is too much. I had time positioned aimed at the angle recommended for solar panels. This meant that warmer water had to be pushed down through the pipe for every wind in the coil. Better is to make water inlet at the bottom and outlet at the higher end in a series of thinner pipes teeing off from larger diameter supply and outlet pipes.
You should hook that up to a 55 gallon holding tank. Theoretically it should work just like a rocket stove hot water heater using thermosiphoning. Without having to burn any wood. Which would be great for the warmer months.
U remind me of a school science project many years ago when at 14 built a solar furnace ( with help of an uncle and a diligent mother ! ) it used a fresnel lens, it would melt lead ! Got second place though lol !
A couple of suggestions: 1. leave a small gap between the pipe 2. leave a small gap between the pipe and the back board. The idea is the maximize the pipe's surface exposure to the hot air inside the box.
@@JM-yx1lm This will allow the sunlight to be reflected to the underside assuming reflective back board. If there is no gap, the sun is not reflected to the center of coil. Without reflective back board, then yes, there is no point.
if the backing was covered in aluminum tape, it might make sense to space the pipe off the board but I think there may not be enough light to pass through between the pipes and heat it from behind. The way I see it, heat would transfer faster from the wood to the pipe if it was directly touching each other. Air is not a good conductor of thermal energy
My only suggestion would be to find some black coating with less reflectivity. I could very plainly see some reflectivity from the black paint used. This is causing some of the sun light to be reflected and thus lost. The coating used should have ZERO reflectivity, it should suck up and absorb all light that hits it. Other then that, no spaces between pipe or airspace below is needed, why? it does not matter to the light ray if it hits front or back of the pipe as long as the light ray is totally absorbed and not reflected and thus converted to heat energy, transferred through the plastic and absorbed by the water. Though the "pex" is very easy to work with, I feel copper tube with a foam insulation board behind and a true non reflective coating would result in more energy being converted to heat and transferred to the water. without insulation board behind the pipe heat loss is going to occur out the back side of this unit. No matter how to slice it, copper is going to transfer more heat energy to the water then that pex plastic is, thus a unit like this constructed with copper and "true" light sucking none reflective coating would be even better = more efficient. This just amounts to quibbling though as this unit obviously works pretty well and is simple. Simple and easy to build = good. ~
I was thinking the same thing, I have a SuperStor tank that stays hot for up to 3 days. I found out once my furnace had been off 3 days when Superstor finally ran out of hotwater.
Years ago my buddies dad took 2 sheets of 4’X8’ 3/4” plywood, built a solid frame (so an 8’X8’)and did this with 1.5” black hose, I cannot remember how many feet of hose it took for all the coils but it was quite a bit. They had an in ground swimming pool about 15’X30’ 4’ deep down to 8’. By hooking the coiled hose into the pump/filter the regularly damn cold pool (3yrs I knew them with a blown and costly heater his dad refused to run), was insanely warm. Even to needing a bypass hooked in (it got too hot). (Not sure if it was needed but he had painted the wood black as well. And it was angled and situated for maximum sun)
Back of the napkin math here. The dowels are 1/2", since the pipe looks a slightly larger than that, it's either 5/8" or 3/4". 5/8" PEX is 1.34 gal/100ft. 3/4" is 1.83 gal/100ft. He said it's about 2 gallons in there, so if it's 5/8" PEX then it's about 150 feet. 3/4" PEX would be about 110 feet.
@@glenmatthes8839 Around 5.19 in the video, it shows 1/2" shark adapters. 1/2" Pex pipe actually has a 1/2" Inside diameter and 5/8" outside diameter, which makes it look a little bigger than the dowel.
There's another video out there - Wilderness camp/research center up north by a lake, they build a giant compost pile the first week of the season, and bury 150 feet of garden hose in it. They use it to make a hot shower from the cold lake water. Within the first week, the water is too hot to use by itself - it is scalding at 160 degrees or so. By the end of the summer, the water is still warm. So many ways to get things done in life...
Jean Pain style. I did that as an experiment. Had hot water for seven of us from January to September.
Brilliant!
What would you do during jan-apr with tllight snow hard freeze of TN mtns? I'm hoping for anything else but electrical or fire based guys please HELP
Happen to have a link to that video?
@@nate5520 Sorry couldn't find just what I was thinking of, but there are various videos if you search compost and hot shower. The main thing is to run 100 feet or so a tube/hose through the pile, and build the pile as big as possible. When it first heats up, the water will be scalding hot.
I taught a few lessons on solar energy in a basic Physical Science class back in the late 70s. I student worked with his father to build something very similar to this. He had electrically operated valves and temperature sensor. When the water reached a certain (HOT) temperature the valves would open and the water line would force the hot water out. When the cold water reached the temp sensor the valves would close and it would start to heat the water again.
I was thinking of doing something similar except to preheat the water going to the water heater. Would it be advisable to place this inline before the water hearer and use the radiant heat of the attic to preheat the water going into the water heater? Have it set up to run during spring, summer and fall and bypass during winter to avoid freezing issues.
@@thomasm0481 your attic should still be warmer than most places of your house in winter--and that would certainly still be a better place for the pipes than under the house. ...but you're going to want to make CERTAIN that you never spring a leak up there.
I built one of these 3 decades ago for my hot tub and it operated with a small fish tank pump. Worked great.
Are you " in genius "? Seriously it is a great Ingenious design worthy of high praise . Nicely done, and cost effectively too.
I made one of those in 1983 with a coil of garden hose on a piece of corrugated roofing painted black. It was a simple ecology conservation project at summer camp to see if we could inexpensively harness the power of the sun. Surprisingly, it worked!
Really I hadn't considered that option. I'll try it w my 100' of garden hose that I have no use for. Thanks
@@jimato01 если не трудно, подскажите, является ли используемая в нагревателе труба устойчивой к ультрафиолетовому излучению? Насколько я понял, это труба из сшитого полиэтилена, которую используют в системах напольного подогрева при строительстве. Насколько хватит ресурса трубы?
@@сергейгостев-н7сIt is not UV resistant by itself so that is why he painted it.
100% guaranteed confirmed bachelor if you're actually building this in your living room with nobody screaming at you. Congrats!
I build all sorts of shit in my living room and have a 75' x 175' yard. I still get yelled at and I live alone! My realtor tells people I'm an artist.
A real man makes the rules a home
Haha so true
And barefoot!
Not necessarily. My wife gave up on me long ago. She knows when I need to make a mess - it's gonna happen with her support or without it.
I love how you show the “after” before showing the build. Most videos show the build first and I’m never sure what I’m looking at. Excellent technique!
hi and thank you for the feedback. i figure people want to see what i actually did (and that i actually finished the project). i often see videos where people start building something but then they never finish the build. their video just ends with no finished project.
I love the simplicity of this, I would cover the inside of the whole base with a thin layer of aluminium or steel sheet. This would help heating up & with your enclosure the thin metal sheet would hold heat for longer. This design gives me ideas for making 3 or 4 of these hung on the side of a house, giving an increased simple water hearing system. I have to say VERY well done, I shall have to go and wash the green with envy off my face though.:)
Desert Sun 2 is an American genius! His videos are short and to the point. His practicality is immense! Thanks!!!!
Should paint the pex pipe portions that extend just out of the box too to give them UV protection equal to inside the box and bag some extra rays too. Great build- very nicely done. I love it.
The solar hot water heater started out in the USA in California with a coil of high temp. poly pipe on the roof. It continues to morph into new and interesting designs. Yours is lovely and compact. Thanks for sharing.
Load of crap. People worldwide have been using solar heated bladders for centuries. Invented in Cali... go smoke some more ganga.
I used to use several hundred feet of black garden hose stretched out casually on the grass in the sun to fill up my swimming pool. Works really well!
SO GOOD! The eye hook and dowling is brilliant and your detailed video/explanation makes it easy to reproduce. Thanks a ton.
You're very welcome!
A friend of mine built basically a similar setup, but on a larger scale. He used 1.5" PVC tubing suspended on T-posts in a coil shape like what a spring looks like. He had two sections of sheetmetal that were 3 x 5 ft on the bottom and one side forming an L. He had ball valves and y fittings and painted everything black. He had it plumbed in line after the filter for his swimming pool to heat his pool. It would literally raise his pool water temp by almost 15° in 30 minutes.
Do we know the same guy?
That sounds great; I’m thinking of in line application using pool pump and guessing the current video setup would cause too much flow resistance. Any links to your friend’s setup or further info on build?
It's a smart design and has aesthetic value, unlike many off-grid contraptions.
Best i've seen, just a heads up to anyone, solar panels have spacing for maximum surface area and coverage from moving light source. Space between hose coils would help that.
I've always liked this super simple free energy method. I like your dowel method for holding all the PEX flat.
mm... me too, but its not free.. the sun's doing all the work.... I know free to us... but most people dont understand why there is no such thing as free energy..
the 2 laws say that.. you cant create energy and you cant destroy it... means you can only concert it from one thing to another..
aint free to the sun.. its burning of massive amount of hydrogen.. lol
@@harleyme3163 Lol, i wasn't talking about perpetual-motion concepts here just sunlight that I did not have to pay for but thanks for the input.
Yes, this is a slick variant of a long standing design. I like it!
I really like the notion of using freeze-resistant pex over copper tubing (for non-potable bathing water). But copper has a huge advantage: it can be soldered into a horizontal ladder for the angled plate collector whereas pex is most easily coiled. And the problem with a coiled layout is vapor lock. Gases readily fall from suspension as water heats, which create bubbles that rise to the top of the coil loops and stop the thermosiphon flow. Unless you're actively pushing pressurized water through the pipes ... no bueno.
copper comes in a coil
most of the time.
best thing to do is to make a heat exchanger.
Super interesting thanks
@@VividDroid I've never seen 1/4"-1/2" in a coil. Basically only propane lines. Besides, you can put 90° sharkbite fittings on pex, no soldering required.
For a broader application, don't think of it as just supplying heated, potable water. Close the system and circulate water that has antifreeze in it. Use that heated solution to warm large heat sinks such as concrete slabs or block walls to store that daytime heat. The heat sinks heat rooms throughout the night. You can also direct forced air over the heat sinks or though heated radiators to heat rooms in a more controllable manner.
Yes. Radiant floor heating for an RV is what I'm thinking.
Water tanks are better sinks for the heat carried by the antifreeze.
Water has the best heat capacity.
I plan to store 200-500l of warm water for underfloor heating the home and bathing and general warm water usage like dish washing and laundry. Big insulated drums with two or three exchane coils per drum.
It's a bit more complicated, it implies a few pumps and a few antifreeze circuits, sensors and failsafe measures but it is doable diy stile.
No need to use Glycol, so outdated, and this is Pex, not copper pipe, so even if water did freeze if left open vented, does not split the tube
@@erichawkins3915 Pex may be able to handle freeze/thaw. Typically, some of the fittings, valves, sensors, pumps, etc, will not be freeze-proof. I'm not aware of a more practical antifreeze than glycol.
@@erichawkins3915 it will fail after a few freezes. PE is plastic, not very elastic. It will expand more snd more with every freeze until it gives.
Wow that's brilliant and works so well. You don't need water hotter than that system, I like the simplicity. Thanks for sharing.
I'm wondering if plexiglass would be suitable?
Great work! Put before the hot water tank would be perfect. Tank heater would come on much less (save $$$) + hot water supply would be consistent. Great idea!
Thats what I was thinking. Maybe Use some big 2" galvinized with a 1/2" out. The metal might add some heat retention to heat the incoming cold water? Might save a couple hundred a year..
Your 30" x 30" box is about 0.6 square metres. On a good day you may capture about 4 kWh/sqm. So you will get about 2.3 kWh of heating out of that setup.
That's enough to heat 33 litres of water from 20 C to 80 C. Useful. Like six of those will heat a 200 litre (44 gal) drum up 60 degrees C (160F) over the day, and that can then be used for heating the house, releasing an average of 2000 watts over a period of about 7 hours. That becomes quite useful as space heating (of course it performs best in the summer, when you want cooling, but never mind). Small solar powered pump as a circulator. Set the panels up in parallel to heat the drum isothermally (i.e. avoid the temptation to maximise heat rise per pass thru the loop). Nice.
Nice job!! Thank you - have a 20 year old copper based system - - its breaking down - from not draining it properly before winter 😉 - going to ditch all the copper and use your approach - I’m fired up!
Very well done on alot of levels. A beautiful design. I am gonna make one myself. Thanks for posting
Me too. I gotta quit watching these videos. But I can't help myself.
Great video. When I wanted to shower, in Vietnam, I filled a plastic 5 gallon water can and set it about a foot from our 3KW generator. About 45 minutes later, it was the perfect temp to pour into the Australian shower bag....5 gallons is enough, if you shut it off after your get wet.
I built one like this years ago for my nephews science project. He won. I used foam board insulation on the bottom and sides to help hold in the heat. We had water at boiling temperatures depending on flow rate.
@S P he had a big hand in helping with it. I instructed him on what and how to do it
@S P what do you care ?
@Svenulf Skjaldbjörn if you're not cheating, you're not trying.
@@colstace2560 exactly
These DIY projects only ever show temperatures as soon as water starts running. What is the % gain after running for a few hours, once the water isnt sitting still in pipe and the pipe has cooled down due to water flow.
This by far the best video I've sent for this build. I also see you are wearing the same brand of safety boots that I generally wear!!!
Year, I hear it's called desert wear. It's popular in Australia too!
2:25 lololol
No pencils were harmed during the making of this video. Good Job !
The company I work for makes solar panels for water heating. I recommend using “solar glass” which is a low iron tempered glass for use in solar panels. You will get more heat gain by using this type of glass. Overall you have a very nice build and are off to a good start. If you want to avoid overheating in summer and freezing in winter you can build this with a “drain back” system.
Thanks for sharing the tips!
I did a heater very similar. It was 4x8 in size. Ran off of a 1/3 hp submersible sump pump. Heated a pool 35 foot above ground brought all that water up bu 5degrees. Worked great.
I also covered mine with plexiglass to give it a greenhouse effect.
I actually made one change. I used spray beeline on of my frame to help weather proof it. Everything else is the same! Awesome!
I followed your method today to build one only did a 4x4 and 300 feet of pex. Need to paint and all still but it seemed to go together well. Thanks for the video.... hope it works
Hey u am thinking of doing one. I would love to see your video on it.
I wanted to say thanks for the video as it inspired me to make my own using the wood scraps I had left over from other projects. My one hang up was getting a piece of glass/plexiglass cheap. I found my answer at Goodwill - I bought a larger framed artwork and used the frame and the plexiglass for the lid of my box made to fit the 42.5" x 36" frame. It fit about 150' of 5/8" tubing . The water to the pool is 96 degrees.
that's great! - i often tell people to build the collector 'around' the piece of glass they can get. it's great you were able to use leftover wood scraps.
habitat for humanity is also a good source for windows, or even craigslist
Thanks so much, you just solved my heating issue for the outdoor Hot tub.
this is sarcasm I hope.
@@thedavesofourlives1 Not at all, it works like a champ.
In my northern climate I have been using the same system in the summer, to raise the temperature of my above ground swimming pool by a few degrees. A 50 foot coil of 1" Corlon wound on a 4x8 sheet of Plywood, painted black with a stapled on sheet of transparent vinyl as a cover. Water is fed by a tap on my water filter pump. When the sun is out I simply shut the valve to the system. The thing sits at the back of my yard and I sunk the pipes 2" under the grass, it gets some more heat from there too and I can mow the lawn no problem. Good from the middle of June till nearly the end of August in my neck of the woods (Vermont). This gives me an appreciable amount of free heat for my pool.
Have watched several videos on this subject and so far yours is the best. Going to do it your way. Thanks for sharing.
sounds great! -i still have this unit and it's still going strong
I just completed this project today. FYI I used 100 ft of 1/2 inch plex. It's not as hot as the 300 ft 1/4 inch coiled on a cross solar heater i made but the flow rate is way faster and I also didn't use plexi-glass (way too expensive right now due to Covid). I'm gonna rework the other one in the same style and link all 4 together. 12ft Pool/Hot tub coming up!!
Nicely done. I think the overall lifetime of this system would be limited by the life of the wooden enclosure not the pex or shark bite fittings. Here in Houston I doubt it would last longer than a single season. You might be able to improve it by using reflective metal like flashing for the inside back of the box and suspend the tubing a small amount above the back wall. That way the entire surface area of the tubing is used to capture energy.
With the wood being primed & assuming it's not treated wood, it would definitely last atleast a few years before it starts to deteriorate. The primer alone adds a significant amount of protection from the elements.
@@jeramychunn9108 I was thinking the treated stuff would last longer? Isn't it meant for outdoor conditions. I'm in Ireland so water getting into the box would be a factor. I'm sure priming it first as you say would stretch the life of it.
We use black hyrdodare piping here for potable water - 3/4 inch or bigger. It's also meant for outdoors and comes in a 25m roll, it might be ideal for this. Not sure about the amount of heat transfer that would happen but it's worth a shot
Pex will fail before the wood
Not sure what the constant heat on timber would do to it . Kingspan between pipe and timber would help
...so you're saying that everything made of wood falls apart after one year in Houston, TX?
Awesome simple design. Did something similar long ago using copper, yours is much much easier. Might consider insulating the outside of the back board and sides & adding another layer or 2 of PEX. Double or triple your capacity without much more effort. Great job, thanks for making this video
If you wanted to in that Center space you could take something that is circular especially if it's made out of aluminum or stainless or basically any metal but plastic would work too and put that in the very center and take one section take put a break in it but your connections and install that tank if you will inline to give you more capacity cuz I think two gallons is way too small especially for the size of that box and everything else how much work goes into it you can even reduce some of the pics link this inside the box to install an even larger tank that would be flat but Square circular that would fit within that sitter space of the loops that you removed
We did a simple thing like this. Just because we had an opportunity to hide our septic pumps and the roof space and orientation lent itself well to preheat water before it enters our water heater tank. We’ll build a bigger and better system for our hot water needs as a whole eventually. We’ll probably still run it thru the water heater tank for storage and consistency. Ours really only turns on at night if we use the water up. During a hot day, it will never come on.
I think using these types of energy hacks are excellent methods of conservation.
The black paint protects the sensitive PEX from UV (which would quickly degrade it).
Pretty Smart dude... Best DIY jobbie I have seen. Anybody could build that.
Light Weight
Low Cost
Simple
DIY
hi and thank you! 🙂👍
Great design! A few years ago, I saw something similar used for heating with larger black pvc pipe and computer fans to move air thru them.
I have looked at these kind of things for decades. This is a simple design. Whatever output this produces IF you put under it a piece of alumium flashing your heat will increase. If you take flat black priner and Spray paint the Aluminum and the hose your output will greatly increase, it will be almost boiling. IF you take Plexiglass and the screw that on time of the painted stuff you will reach the marximum output.
NOW if instead of Plastic you use a copper coil doing the above things you can get a parabolic mirror and shine it on the copper and metal and the water will reach boiling point.
The Idea here is to have a tank that would allow the high pressure heated side to push into a tank and to have a check valve on the low side so the cooler water could only enter your tubing creating a natural siphoning action to circulate the hot water. In Very Old Houses they had a water tank in the attic that was the domestic hot water for the summer.
Cheers.. .
I like your idea of using the copper pipe, but also use a metal box that can take a lot of external heat., so you can put a fire pan under it for a heat source on overcast days or at night.
....hot water tank in the attic...
Pics of that?
@@mikevickers4727 Here's a link: www.abbeyboilers.com/cold-water-tank
but these are for cold water tanks.
That can't be from a very old house. They didn't have plastic back then.
depending on the usage, plexiglass will only restrict sun rays and make it less efficient. But that all depends on his flow rate
Built two of these 4 years ago for my above ground pool. 4’x4’ each. Mounted on my pool deck directly facing the sun. The plastic pipe lasts a long time the wooden component are showing signs of damage. Although water exiting the unit after it has been shut off for a bit is very hot , too hot to touch, this type of unit does not sustain a constant high temperature. After a couple of minutes the output temperature will be only 4 or 5 degrees warmer than the pool water. Considering the pool has several thousand gallons of water, I’m not convinced the pool temp increases a significant amount. I will be moving my collectors to my shed roof in hopes contact with the roofing shingles will add more heat to the pipes. Also be sure to stop the water flow through the collector at night to when cooler water will be pumped back to the pool.
I would think two 4x4 panels really might not make that much of a dent temp wise William when you consider # of gallons in the pool, constant cooling due to evaporation, heat loss due to conduction, etc. Maybe a good solar pool blanket would help if you keep the pool covered when you are not using it. Amazon has temperature controlled relays for fairly cheap to keep the system on only when the panel temp is high enough. Beyond that, more panels. Good luck amigo.
@@sempertard I hear ya The solar covers really aren’t made to use to heat the pool. Their function is to insulated the pool especially at night when the air temp drops below the pool temp , minimizing heat loss from the pool. Although using a solar cover will reduce evaporation of water and your chlorine, it will insulate the pool and trap the cold water in the pool. It’s best to let the sun shine directly into the pool.
@@williamsrmonroe8406 As a longtime inground pool user in Texas I can say your info about solar covers is mostly wrong. Your statement about using the cover at night (to deter evaporation which retains warmth) is correct, but when the sun beams the cover becomes a very effective heat source that is transmitted directly into the water. My results are 4 to 6 degrees + in a day's time. At night the water tends to return to the temp of the earth beneath/surrounding the pool.
Was very sceptical at first. Then was pleasantly surprised. Hooked up easy. Took two days and wow the temperature change was just awesome. So we ordered again and now the pool stays around 30c.
Nice project... Here in my house in Brazil, I use a 1/2 inch irrigation pipe and I put a system with arduino to control the water temperature by sensor and turn on a 12 volt pump connected to a solar energy board to move the water.
In summer the water temperature reaches 65 degrees Celsius.
Hi from Sunny South Africa, can you explain your system, I am now actually testing with sonoff wifi switches and temp probes each on inlet(Cold water) and another outlet (heated water). If the preset temp in the outlet is sensored to the preset temperature, it starts the 12VDC pump to push the water into the feeder tank which is connected to the 150l geyser as preheated water to get the best efficiency and pay less utility bills. the feeder tank hold enough water(around 200l which means the system must produce 400 litres a day.
Adding an insulative backing behind the tubes could decrease heat loss by conduction into the wood panel making your system more efficient (hotter output). OSB already has a pretty low thermal conductivity, but most insulation has thermal conductivity an order of magnitude lower.
I was thinking that if he could make a vacuum sealed box and get most of the air out then it would probably boil water
@@donnyh3497 This is how vacuum tubes work in solar heaters. Anyways replacing air with CO2 or a better greenhouse gas might further increase its efficiency,
@@johnzach2057 Air is actually a really good insulator, co2 counter intuitively would decrease the efficiency because it absorbs the heat and radiate it back out of the panel.
Very interesting build. I tried to make a passive batch water heater our of a water heater tank painted flat black. Given the free cost it worked out well for the weekend cabin.
Nice idea. Pex and Sharkbites are so easy to work with.
... That leaky faucet though!! LOL! Need to add a .10 cent washer to the project budget.
I built one just like yours in 1972 using copper coil from a hardware store and salvaged tempered glass from a demolition site and of course built the wooden box. I also added a standard water heater pressure relief valve on the outlet. Worked great. That new pipe should make it cheaper. Good luck.
sounds great!
The pretty chrome trim on the shark bite valves are also a removal tool for taking off the valve if need be. Just turn it around and slide up against plastic protruding from valve and press in. Should then slide off of the tubing.
If you would like the temp to hold hours after the sun goes down pour some black sand on to some spray adhesive the silcate will keep the temp up hours after the sun goes down.
Great Idea!!!!
You could line the bottom with ceramic tile if you want to hold the heat.
This might be a silly question but where do you put the sand?
But that's what the water is for. The water will hold the heat for hours. It's the best thermal mass we have.
@@darrellsomerville8092
..."also". You meant to say. Lol
Can you make a video of how to attach it to the hot water tank so that we can mix it with the cold water tap? Not only is this a great idea but you do a clean and efficient construction. Makes learning so much easier.
Just disconnect the pipe that feeds your water heater and run a pipe up to your roof, tie it in, and another pipe to bring the water down to then tie into your water heater. I made one with a bypass and drain downs for the winter. Be sure to use an expansion tank ! I did not penetrate the roof but came out the side just under the eaves
You are going to want to install a Thermostatic Mixing Valve after the water tank to prevent scalding. It mixes cold water into the hot water to your desired temp amzn.to/3wHjZYu
When you say mix it or add it in line to your cold water tap are you speaking about the line that would come to your fixtures for cold water cuz if so then don't connect it to that if you're talking about the line that feeds in the tap water into the hot water heater that comes out hot then that would be okay but you always want to have the cold water at a much lower temperature than the temp of the hot so you have some way to balance
Installing space between each wrap of the coil will increase the surface area being hit by the sun and increase your heat output. Another way to look at Less of it will be in the shade. I have done this and after my first attempt, I realized my flaw and leaving a gap is an additional 25% more BTUs. Your design is very neat and tidy.
msears101 how much space between wraps did you use in your design? Your recommendation adds to the success of the build. After more than 9 days of no power in last years hurricane, it would have been nice to have this as part of my backup up kit.
Please show us in your video!
How did you space it? What did u use as spacers?
I just bought all the parts to make this. I will report back on how effective it is. I have a pool I want to heat up and was going to hook this up to the circulator.
sounds great!
I'm in arizona where its sunny 363 days a year.
I just throw the old garden hose out in the sun for about 30 seconds and turn on the water. The length of your hose is directly proportional to the quality of your warm (if not hot) water needs.
Take care. Different hoses are made with different materials some of which are toxic. I've pondered whether you could use safe white RV hoses used for potable water and paint them black. There might be dark colored potable water hoses already available
I must say this is impressive. Couple of improvements on materials though. Buy the PEX in "Black" and then replace the glass with "Cell Cast Acrylic". The cell cast blocks 95% of the UV rays and is much more durable and you can cut it yourself. Google my suggestions and you will see I speak the truth. All the credit of this project goes to you my friend!
How much is a 4ftx4ft sheet of cell cast acrylic? Can you buy it at the hardware store?
I assume the blockage of UV rays doesn't restrict heating?
Long-term it's gonna eat all those connection
I wouldn't allow a 10 year seal on these
The only way you'll get that up to 135° is to let it soak in the Sun. After the standing water from the tubing is depleted the temperature will drop drastically. Made something very similar years ago, but I used to holding tank. But the cold water thermosiphon through the coil to the top of the tank for storage and then fed my tankless coil on my oil boiler. On a continuous run in the Sun you would be pressed to gain more than 10 degrees from start to finish.
There are so many naysayers! This is way cool! And with your ingenuity you’ll be able to do a lot with this. When I can find the time I think I will Make one myself. Thanks for sharing!
We made one 30 years ago using rigid PVC and plumbed into the system on our swimming pool, worked great to heat the pool.
Did you incorporate a means to control water temperature ?
@@davidlevesque2763 Didn't get that hot, just helped when it got colder
How much would you say it raised the temp? What size tubing did you use?
@@keokib7575 Hard to tell, it was a motel my parents owned and we covered the pool at night but I would say 10 degrees using 1 1/2 painted black
Your videos are the best! Thank you for all your contributions to the community!
hi and you're welcome! 🙂
Amazong! Best Solar pool heater I've seen on TH-cam!!!
thanks 👍
Nice looking job! Questions: 1) What Pex hose diameter did you use? 2) On a sunny day at about 50 degrees F, how long does it take to heat ground water to about 140 degrees? Thank you.
Did you get an answer to your question? It looks to be 3/4" to me.
Would be nice to see all the temperatures and flow rate to see how constant the temperature would be. What was the inlet temp of the water? What was the outside temperature? Great design for sure.
I love the idea of solar water heater! With the use of tank booster mixing valve to not make it too hot and increase usable capacity, I think this could work. Is there any danger of overpressure when sitting in the hot sun when water is not actively running and therefore, do I need a pressure relief valve? I'm thinking about putting this behind my electric tankless water heater so that it doesn't have to work as hard during a sunny day and save on utility bills.
Back in the 80's, I had a married neighbor couple that were ex-hippies. They bought a small school bus to convert into a motor home to do some traveling. I helped them build a solar hot water heater just like this that they could mount atop their bus after parking it. No such thing as PEX back then, but polypropylene irrigation tubing was cheap - and I used two coils - 200 feet - of it and built a double box arrangement just like the one here. They loved it.
Now I am tempted to do it again using PEX and shark-bite fittings. I would also add some aluminum sheeting to go under the hoses - and paint everything flat black, then used acrylic or poly-carbonate for the window - not glass.
Why would you heat hot water? You want to use lead-free glass, that way all the rays get through to the tubing.
I note that PEX is available in Blue....which you may find absorbs heat from the sun a good bit better....I painted the deck of my schooner a very light sky blue before going to the tropics....and once there had to repaint in tan. The blue deck had to be sluiced down with a bucket of water before you could walk on it...the tan was warm but never too hot to walk on....good luck with your projects! -Veteran '66-68
This is the prettiest one I’ve seen so far. Great job!
I met a guy 10years ago in Canada that made one of these but with copper pipe. Great idea for mobile hot water.
I just figured how I'm heating water for the boat I'm planning.
@@doughesson Yeah, buy a kettle. This contraption will do nothing but give you about a gallon, if that, of hot water. Once the water is replaced in the coil with cold it will need to sit and heat up before more hot water can be extracted.
Volume production? Like could you take a shower? Recharge time?
Also depends on the amount of rise from ground water/water supply temperature.
Just make more of them in series with an in line pump. Add more as needed. Seems solid.
At just under 2 gls. & 140+°, adding just enough cold water to make it compfy do a camping shower.
,1. Adjust flow & temp
2 get in shower wet down
3.water off
4. Soap up
5.water on
6 rinse n dry
No biggie and this is a great design.
I'm making one for my country hut.
Just let it feed a water heater, and lower the utility bill.
Very good , going with nature is definitely the way forward . Solar thermal is certainly under used and when it is too much tech is involved to increase cost and maintenance
Totally agree
Great build and very informative. The only issue I have is my OCD kicked in with the last innermost part of the pex not going under the dowel. Did that bother anyone else?
Same here.
Hot plastic on a sharper bend may kink. Bothered me yes but I’m assuming that’s why.
🤚
Yes.
🤚🏼
From the thermal capacity/efficiency to trap/conduct heat, how does plex tub compare to copper?
Hi guys, just wanted to let you guys know I actually built one of these today following the specs that he gave, so I used roughly 90 feet of PEX. To me the hottest part was getting it to sit flat inside the box when you were winding it around, he made it look very easy when he was doing it but in fact it was very complicated and difficult but I did get it with a couple of hands helping me and I had the sun hitting it for about a half an hour and the temperature spiked up from 75 degrees to 110
Does it work in the winter ?
This is pretty great, it would be an awesome setup for a camping shower or for a passive heater on the roof of a house, hot water is circulated from the roof heater down through a super insulated very large storage tank during the day heating the water in the tank to possibly 160F+, then at night the circulator pump stops and you have this huge tank of hot water for showers in the am or running the dishwasher, etc for virtually minimal cost, no fossil fuels.
Consider making future boxes larger from 1x6" poplar(added room for insulation, see below) and plenty strong with much less weight. Several hundred feet of 1/2" copper tubing will allow more heat to transfer into the water faster as copper is so thermally conductive. Insulate the box back and sides with ridged foam board. Have a standoff for the tubing so there is hot air behind the copper tubing in In front> increased heat transfer into the water which will give hotter water or more gallons of lower temp water.
In a concrete roof in Cali, Colombia laid down 6" of Styrofoam with bar on top. Attached 100' of pex. Imported Sharkbite to Colombia. Attached concrete on top. Nice hot shower and kept the room cooler. Got to 120F by 11:00 AM. Used electric shower head, when cold.
Only use CPVC!
I see this as a way to pre-heat water for a smaller 8kW on-demand water heater.
The lower power units will work with good flow if they don't have to raise the temperature from 50F to 105F.
If you're starting with water preheated to, say, 95F, then you can shower full blast!
Your right about painting it. It will last if you keep those UV rays off the pipe. PEX is sunlight resistant for about 30 days will break down fast in direct light. You might want to paint or cover those ends where your valve is and the connection side too or your solar heater pipe WILL break there. Good project, thanx for the idea.
It can last, hot and cold doesnt effect it. The pipe is freeze/thaw stable its the UV from the sun. Take that pipe you have now thats been outside, if its been subject to direct sunlight, bend or flex it back and forth you will see perfect broken circles in the pipe. Keep UV off and it will almost last forever...
Lee the Fixit Man would be great if some manufacturer came out with a black pipe. Then no need to paint.
@@JohnnyMotel99 Wouldn't work unless the pipe was treated for UV absorption. You will have a trade-off for cost.
Why not use drip irrigation tubing?
That is an efficient use of the pex if it's portable & can take it inside when outside temps are below freezing. I built a heater out of pex too but since its mounted permanently outside, I had to make many horizontal loops at a slight downward angle with a drain cock at the bottom to let it drain out if it freezes. Has less pipe per sq ft than yours but more practical in a permanent situation. I use a thermal sensor switch to turn on a circulating pump to store the hot water in a regular tank water heater & get scalding hot water all summer & working on a bigger collector now to do the same for winter.
what specs on the thermal switch? thanks
Built 2 lined the inner sidewalls with foil for a little extra heat..mounted them on top of my xterra and now I have a gravity shower and a hot water supply for my built in kitchen sink for my cooking station mounted on the back...fishing and camping on the beach in the OBX here I come...
Very neat! If you add some EPS, XPS, or polyiso behind the tubing, you'd undoubtedly recover even more heat.
What a fantastic Solar Project! Thank you for sharing this... 140 degrees is the same as a regular household Water Heater...perfect. This is such a better idea, than using a plastic barrel, painted black...
Lighter, portable, and more efficient!
cool design. I am thinking about building a couple of these to heat my swimming pool during the fall and spring.
Awesome idea! Thanks for sharing this. It also gives me an idea: I once built a large aquarium (for frog breeding) out of plywood. You heavily "paint" the inside of the plywood box with epoxy. I had it for years (indoors), and it remained water tight the entire time. If you did something like that here, you could put a simple valve in the side, and evacuate the space with a vacuum pump, which would, I think, greatly increase the efficiency. Thanks again for giving a great example as it is, and for providing food for thought for changes. I want to make one of these for a four season, cold winter, greenhouse (with water barrel heatsinks).
I want to use that idea for my driveway in the winter melt snow no snow blower hell yeah Love the idea
Theres a vid on yt about a guy that put something similar in his driveway... It was not impressive... I believe green bay packers have a heated field... Dunno how well it works but ive read its only good in a narrow range of temps/snow volumes.. ??
Nobody else realized this guy is putting this together barefoot. Madlad.
Just as an FYI, whenever mixing plastic and metal, always try to make it so the plastic goes inside the metal fitting, as metal is much stronger. If you put metal into plastic sometimes you can crack the plastic.
This design is almost perfect, and is something I have been considering for a long time. I would just add two things. One, a thin layer of foam insulation behind the pipe to stop heat loss out the back. Two, I would add a solar powered water pump. When the sun comes up, the water and heat start to flow. When the sun goes down, everything shuts off. Have you given any thought to adding those features?
Been doing it your way since 1972, then with copper now ped. The trick is a strong enough pump with very small panel (.9a).
Ray Opeongo what size pump would you use
@@robertgeorge9909 Hi Robert, any tips on which pump to get or what specs to look for?
@@robertgeorge9909 higher voltages will result in less amps.
Brilliant video, really thank you. Can anyone tell me if it's more efficient to also paint the window/glass black also! I've seen designs painted and designs clear like this.. just wondering if it's down to preference or if one is the better option..
Good stuff! I wonder if you could put one-way radiant film on the glass (with passing side facing outward allowing light in, and the reflective coating on the inside) to help trap even more heat within? I know thermodynamics won't allow it to completely hold on to all of that radiant energy, but it might be able to drive the temps up slightly higher? Just a thought.
It's now that more people are trying new things and finding better ways everytime someone comes up with ideas
After seeing so many comments about people wanting to daisy chain several of these boxes together or how to get more capacity I just want to say that you don't have to use that thickness of PEX pipe you can use other plastic hoses in piping that is available online and at some of your hardware stores so if you were to go from say 1/2 inch inside diameter to 2 inch inside diameter hose you would have effectively increase your capacity Eightfold
Wow, have to try this to heat the pool this spring.
I would like you to elaborate, what was the outdoor temperature when you did this test, also I would like to see a winter application where it's cold outside on a sunny day and see what kind of temperatures you get, very nice build.
Open the faucet wide enough to get any type of volume and the water would be cold after 30 seconds.
@@FixNewsPlease exactly that's why you do the test to see how much hot water you can get on a certain temperature day
@@FixNewsPlease yes 100' of 1/2" PEX would hold only a gallon of water so basically only 1 gallon of hot then slightly warm. Need something metal to transfer heat but definitely this is cool idea especially if used with temperature mixer to combine hot and cold then could definitely use as very fast shower.
@@clintg3435 you’d want it attached to a tank, not just a hose like the demo. It will even circulate without a pump if a tap at the bottom of the tank enters the heat collector and the hot water out reenters at the top of the tank, provided that the heat collector is not positioned higher than the water level.
@@Goodwalker720 I've seen something like that for flame generated head where the heat causes the water to circulate but not with solar. I would assume the same properties would apply. THanks.
Good job ! Now make it a closed circuit and heat up a big boiler. Don't forget a pressure relief valve
No need to close loop it, thats as outdated as are unvented pressure cylinders, use a Thermal Store, which can provide heating as well as potable hot water.
Three years ago i mare two of these to help warm my aquaponics system.
It certainly did help increasing water temperature. Yet I would not build it like this again. The friction I. The length of pipe is too much. I had time positioned aimed at the angle recommended for solar panels. This meant that warmer water had to be pushed down through the pipe for every wind in the coil.
Better is to make water inlet at the bottom and outlet at the higher end in a series of thinner pipes teeing off from larger diameter supply and outlet pipes.
@@fredvanleeuwen9996 Like this? www.builditsolar.com/Projects/WaterHeating/ThermosyphonDIY/Thermo14.jpg
Is this 100' of pipe?
You should hook that up to a 55 gallon holding tank. Theoretically it should work just like a rocket stove hot water heater using thermosiphoning. Without having to burn any wood. Which would be great for the warmer months.
Can you imagine this on top of an RV or van! Love the video!
thanks! 👍🙂
U remind me of a school science project many years ago when at 14 built a solar furnace ( with help of an uncle and a diligent mother ! ) it used a fresnel lens, it would melt lead ! Got second place though lol !
A couple of suggestions:
1. leave a small gap between the pipe
2. leave a small gap between the pipe and the back board.
The idea is the maximize the pipe's surface exposure to the hot air inside the box.
The second tip is a damn good one. The 1st one i dont see a point.
@@JM-yx1lm This will allow the sunlight to be reflected to the underside assuming reflective back board. If there is no gap, the sun is not reflected to the center of coil. Without reflective back board, then yes, there is no point.
A gap between the pipe allows for slightly more exposed surface area. Might yield some additional power. Also would allow for expansion & contraction.
if the backing was covered in aluminum tape, it might make sense to space the pipe off the board but I think there may not be enough light to pass through between the pipes and heat it from behind. The way I see it, heat would transfer faster from the wood to the pipe if it was directly touching each other. Air is not a good conductor of thermal energy
My only suggestion would be to find some black coating with less reflectivity. I could very plainly see some reflectivity from the black paint used. This is causing some of the sun light to be reflected and thus lost. The coating used should have ZERO reflectivity, it should suck up and absorb all light that hits it.
Other then that, no spaces between pipe or airspace below is needed, why? it does not matter to the light ray if it hits front or back of the pipe as long as the light ray is totally absorbed and not reflected and thus converted to heat energy, transferred through the plastic and absorbed by the water.
Though the "pex" is very easy to work with, I feel copper tube with a foam insulation board behind and a true non reflective coating would result in more energy being converted to heat and transferred to the water.
without insulation board behind the pipe heat loss is going to occur out the back side of this unit.
No matter how to slice it, copper is going to transfer more heat energy to the water then that pex plastic is, thus a unit like this constructed with copper and "true" light sucking none reflective coating would be even better = more efficient.
This just amounts to quibbling though as this unit obviously works pretty well and is simple. Simple and easy to build = good.
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You should get this water in some kind of a storage tank and have it circulate. This is what I would do anyway.
I was thinking the same thing, I have a SuperStor tank that stays hot for up to 3 days. I found out once my furnace had been off 3 days when Superstor finally ran out of hotwater.
I would just build a large box out of styrofoam, about 4 inches thick. A lot cheaper and holds a lot more. Not connected to city water though.
For how long time the water can stay hot once the sun is setting? Thank you!
Years ago my buddies dad took 2 sheets of 4’X8’ 3/4” plywood, built a solid frame (so an 8’X8’)and did this with 1.5” black hose, I cannot remember how many feet of hose it took for all the coils but it was quite a bit.
They had an in ground swimming pool about 15’X30’ 4’ deep down to 8’. By hooking the coiled hose into the pump/filter the regularly damn cold pool (3yrs I knew them with a blown and costly heater his dad refused to run), was insanely warm. Even to needing a bypass hooked in (it got too hot).
(Not sure if it was needed but he had painted the wood black as well. And it was angled and situated for maximum sun)
Using a larger diameter pipe in the box compared to the intake/outlet will slow the flow in the heating zone and make it even hotter.
How many feet of PEX did you use to get that temp? What was the ambient temp too? Looks good!
Back of the napkin math here. The dowels are 1/2", since the pipe looks a slightly larger than that, it's either 5/8" or 3/4". 5/8" PEX is 1.34 gal/100ft. 3/4" is 1.83 gal/100ft. He said it's about 2 gallons in there, so if it's 5/8" PEX then it's about 150 feet. 3/4" PEX would be about 110 feet.
@@glenmatthes8839 Around 5.19 in the video, it shows 1/2" shark adapters. 1/2" Pex pipe actually has a 1/2" Inside diameter and 5/8" outside diameter, which makes it look a little bigger than the dowel.