Thanks for posting. In 1970, I build one of these for a science fair project. I elevated the storage tank (a 5 gallon metal can) and used thermal convection to circulate the water. Worked great and was a great demonstration of solar water heating on a budget. The whole device cost less than $20 to build and was a fun project.
For some reason I had a problem getting mine to circulate by convection. Once the water boiled it caused pressure in both directions within the pipe and would just repeat with no circulation
@@drd1924 The tank has to be elevated above the top of the collector. The water should never boil. The size of the hot and cold pipes to the collector should also be of sufficient girth to allow unrestricted flow between the storage tank and the collector. I won the 6th grade science fair with mine. I was 12 years old then. Enjoyed the heck out of building it. I still have the collector that I built in 1970!
@@winfordnettles3292 Gotcha, thank you sir....Perhaps my pipe size was too small to allow sufficient flow for exchange...Will try again. I was also thinking of installing a check valve to ensure proper flow direction should boiling occur
In Australia, 80's. There was a same system unit called 'Suntrac'. Had 2 reflectors, about 5ft long, 2-3 ft wide. Tank on the top, clear covers, and a water pressure tracking system. The centre pipe was sealed with a gas inside, this pulsed the heat into a sealed end bulb within the tank. Worked well.
Thank you for taking the time to put this together. While there are lots of interesting comments, know that I found you while looking for examples of how to heat just over a cup of water to use in my Aeropress. I don't need a capacity of more than one cup, so this solution is among the tops. We're soon to be full time RVers, and want to figure out unique ways to conserve LP/electric. Thanks again! :)
In the '80s........I had a house with two four by eight solar panels in Massachusetts......... With one sonny day it gave me 160 gallons of hot water..... Heat exchanger, recirculation pump, anti-freeze.........it was all a great idea and savings..........this system looks to be more compact, and more efficient. Thanks for sharing.
I though about this concept a few years back. I can see that it works! What I was also thinking was, since I live in a tropical country we have great exposure to the soon through the year, so I was thinking that it might be possible to reach boiling point with a little bit more industrialize set up in order to be able to get salty water from the sea and take the salt out! It could be inefficient but the sun is free so...
a donut ring of seawater, the vapor dripping from an upside down cone in the donut hole to the freshwater container underneath, the tide refilling the seawater part, solar power to provide electricity to pump the fresh water up to a roof tank
1) Build parabolic mirror similar to the size in this video. 2) Install a clear glass oven pan with sea water in the pan. 3) The sea water will evaporate and rise as steam. 4) That steam is pure water. 5) Instal a thin sheet of clear acrylic a few inches above the pan. But angle the acrylic so that the steam droplets which gather on the àcrylic will slide down the surface of the acrylic and fall off into a separate pan. Voila! Clean water.
FYI, that type of Pyrex measuring cup is made from soda lime glass. Rapid temperature changes, such as pouring boiling water into it, can lead to violent shattering of the glass. Cool demonstration though! Thanks for sharing.
I am really grateful for your precious time, used in this demonstration video of this simple and at the same time so fundamental and important for the development and improvement in our homes, not to mention the economy with the consumption of electric energy, and not to mention that the steam of water can also be used to generate mechanical and electrical work, through a hot air engine using a coil for example. congratulations and thank you very much. big hug my brother
Back in the early 80's I worked for a company who installed this type of hot water system in Nevada. Pre built 8" long parabolic collectors with blackened copper pipe set into an aluminum framework on the roof of the house. the system had a sun tracking feature that kept the collectors facing in the optimum direction while set at the best average angle to the sun for the latitude. This was a closed loop system. Meaning no household water entered the system. The system water was pumped through a heat exchanger tank and back up into the collectors. The house hold water passed through the heat exchanger into a storage tank and then into the existing hot water heater and into the house. This method allowed the existing system to be isolated in case of emergency. On many occasion during initial start up I watched thermometers go from ambient air temps of 50 degrees F to over 250 degrees F as fast as the needle could move. As the system would run this temp would come down to a more reasonable 200 degrees f. The normal operating temp of the system was designed to keep the household water in the 105 to 115 degree range. This technology should and needs to be utilized more these days.
@@drd1924 The tracking feature was simplicity at it's best. There was a photovoltaic eye that had a small riser held above it essentially dividing the eye in two. as the sun moved (earth rotated?) and exposed the eye to sunlight a small motor connected to a chain drive would activate moving the collector just slightly to re-shade the eye and stop the motor. The riser was flat on the bottom and half circle on the top this allowed the eye to catch the correct amount of sunlight throughout the year without adjusting it.
@@NVOutsider Very creative!, Thanks for the explanation I figured it had to utilize some sort of CDS cell, whats puzzling me is... Did it know to reverse directions in the morning to start over or did it have to be reset every day?
@@drd1924 the riser piece was 1/16" to 1/8" thick painted white aluminum. It sat directly over the center of the eye. so when the sun set the collectors stayed facing west as the sun hit the eye in the am everything would rotate to the east and start the process over. I have a feeling my explanation is really dumbing it down due to my 18 yo lack of understanding and it being about 40 years ago. The system was manufactured in Arizona by a company called USMC (?) What is a "CDS" cell?
@@NVOutsider Hi, A CDS Cell is short for Cadmium Sulphide (a light controlled variable resistor, The Photoeye) Thanks again for further explaining, rotating would make more sense. I was picturing the mechanism Panning and could only think of using limit switches to stop the movement and reset it. But simply rotating would simplify it even further...Very Cool
Well not with the prices going tenfold in a few months this will become very very relevant. Thank you for your great video. I have about 16 months to master how to use alternatives for heating our house. I found already some very usefull stuff.
Mount this below a water tank, then allow convective circulation to heat the water in the tank by day, then by night, the heated water will stay elevated in the tank. Likewise, make another radiator, but mount it above a second tank, to cool the water by night with convective circulation, then by day, the cool water will stay low in the water tank. This way, you have both hot and cold water available.
Thanks for sharing practical scalable DIY tech that anyone who's sat in a car on an overcast winters day could understand the principal being demonstrated. Thanks nice modular system.👍😊
I built one of these for a science fair project in the late 1970's. I painted the copper pipe black, which made it heat up a lot faster than the bare copper.
This is great! I wonder how much difference it would make to paint the pipe a flat black, just a thin coat, maybe with BBQ or exhaust system paint, or if oxidized copper is sufficient?
Use a horizontal arc that way it always point at the sun, the double curve is harder to make but doable with a flexible material, or just section and angle the sections to follow. This obviates the need for tracking. Also paint the pipe with flat black high temp. engine paint, so you get more frequencies absorbed.
I wonder if we could use the system to heat a working fluid so it could expand and push a hydraulic piston to follow the sun? My idea was to use the heat from solar panels to automate their turning.
Very informative video. It is great that the use of copper is limited to one central pipe vs a long copper coil or multiple parallel copper pipe collector as copper is expensive. While glass mirrors would reflect more solar energy mirror polished stainless steel sheet metal would likely be more cost effective. Solar concentration is a great technology but it does have some drawbacks to be usable for the lay consumer. Boiling in a water heating system is not ideal as pressure builds up and could cause bursting issues. There would have to be some type of circulator, heavily insulated HW storage tank, temperature monitoring device, and a device that will shut off the circulator when approaching the boiling point of water as well as to rotate the collectors out of the sun. Also having to manually adjust the angle of the unit every few days is not feasible there would have to be some type of mechanical unit to pivot the collectors.
I could be misremembering my college physics, but it's not a coincidence that it stopped at the boiling point of water. It stopped there because the water was boiling. Liquid water can't get hotter than the boiling point. All the energy going into the pipe was going into producing water vapor. After all the water boiled off, the pipe would start getting hotter. It might have melted the copper eventually. It would be interesting to know how big a reflector you'd need to heat a water heater full of water from say 70 F to 160 F over the course of a day.
Thanks for an inspirational video. I nearly got it correct, I have the parabola built. I have not yet put the copper pipe in. All my experiments to date have not worked for a couple of reasons: 1/ no copper pipe (WHAT I have to have a pipe at the apex of the parabola?) (Answer: DUH!) 2/ not a shiny surface. (Unsure what material I used, I think is stainless steel) All that said, my construction is very similar to your, except I do not have a center support, but it is very ridgid. Loved the safety comments, like don't pick it up by the pipe, err sorta been there done that. (think, wet paint DO NOT TOUCH) Thanks mate
A good solar still easily reaches 50°C under sunlight and offers pure, hot water. An autonomous, off-grid user doesn't need those expensive solar hot water panels. Just a plastic sheet and a pump is enough :-) .
my Grumman Sun Stream solar water installed in 1978 COOKE water for thirty years before the A O Smith stainless steel tank began leaking. The optimal tilt is 37° , I had 45° in my location. on Dec 21 , a partly dsy, the late afternoon tank temp was 97°. 80 gallons of warm water when the incoming temp was 52°. Cost with tax credit: 1695.00 Install labor 350 antifreeze replace 300 total cost $2445 reduction in electric bill was over 200 kwhr per month 200 kwhr yearly or $240.00 per year electric cost 80,000 lbs of pollution ! A hybrid water heater cost $1395.00 and will reduce electric bill almost as much as the solar water heater.
If you install one way check valves the heat of the water will propel the water through the pipes/hose on a continuous flow. And I agree painting the copper pipe black will increase it's effectiveness and will draw the water from a tank or vessel and pump it into another tank or vessel.
This can heat fluid to circulate in hydronic heat system, too…putting 1-way check valves moves the hot water in the direction wanted, so it can recirculate. Can also use thermostat to control it. Needs an expansion tank also. But it’s a fairly low-tech system that can work even in winter, as long as there’s enuf size to system, & cloud reflectance. A backup small tank water heater can also be in the loop, for dim days & nites.
This can be implemented across regions where there is no access to electricity, I hope social conscious young men like you can provide this system at minimum cost or for free to people in need. Thank you for your interest.
I am assuming that you would need a water expansion system for the hot water. Also, I would use a glycol of some sort instead of water to prevent freezing in winter. How about a large insulated heat sink to preserve the heat. Have the tubing to the house run through the sink to absorb the heat and distribute either to the domestic hot water or some form of radiator set up. I'm looking at our mountain house and trying to keep the energy bills low enough so that I don't have to sell it with the prices of power these days.
This reminds me a lot of the solar air heater. It looks good with static air. But once you start cycling air through them, you find they have a very low capacity to heat a volume of air. I suspect the same is true with your solar water heaters.
Would blackening the pipe add efficiency ? Could you make a return pipe e.g. behind the mirror and a reservoir on top using thermal circulation to heat a larger volume ?
The technic is called "solar collector" and is much more effective to heat up water directly as solar cells - where the flat collector have lower efficiency than tube collectors, even at low outside temperatures.
Would like to have seen if that device could heat running water THROUGH it, to actually know if it is feasible to install into an off-grid water system! Putting a half cup of water into ANY metal container, out in the sun, even without a parabolic refractor, would still heat the liquid!
Imagine a connecting the bottom to a small plex hose that goes to a small cup reservoir elevated to the just below the top of the solar exposed pipe when elevated as in the video. As water evaporates/boils away at the top, new cold water is gravity fed into the bottom from the reservoir. Helping keep water throughout the solar exposed pipe for maximum heat transfer. Then one can use the steam given off at the top to cook food in an insulated steam box.
I think i came up with a one way heat diode. My idea is that id have a few energy collectors and a heat battery. Have them dump the excess heat into the battery. Otherwise it would just heat up a water heater. Or it would heat up a air dryer. I have an idea for a filtration system that uses water instead of expensive filters. I haven’t figured it out yet but ive seen the system used in paint booths. I just need to dry the air after it comes out or it would grow bacteria eventually. Also we can use our waste stack as a heat dump. I was thinking we use our sewer as a geothermal heat dump. So the first goal is to generate an excess of heat. That way i have enough of a heat differential to generate energy. Once the heat battery is hot enough for steam its a wrap free power from nature with just maintenance or what ill do is select materials that need almost no maintenance. Actually im thinking of making a open source youtube series on what i think the perfect house would be. With some help i believe instead of a net zero house we can make a -100% house. With it capable of absorbing and holding nearly every pollutant humans make and turning it into a clean energy. With the filtration system i mentioned we would be cleaning the air we take in from the outside of road dust and other fine dust pollutants. We would have a cooling effect on the ground similar to the shade a natural forest would have. (Thermal pollution a theory i came up with in 2010.) and most importantly and obviously provide energy instead of take energy.
How much water you producing with that little thing? When the power is off I have laid black garden hose in the yard and fill it with water and let it stand for a bit. Gets pretty hot. Won’t boil but hotter that you can stand.
I am going to try this to heat my water supply with this unit. Do you have any recommendations from yourself or TH-cam videos you think are worth looking at and executing on that information Sir ??? Thanks
All these solar panels sitting on top of homes have lots of heat. All that heat reduces the panels life and efficiency. They need to be sealed then water induced. Thus providing free electricity & hot water without depleting your electric reserve. I've done it on a small panel. Used a parabolic dish to focus the sun on the panel. Then ran water through it. Resulting in tripple the electric output~!
Just a suggestion, wouldn't it be better to have the reflector support on the outside? Because when there's those wooden things inside, the shade from each would decrease the overall temperature as sun rotates? I'm about to build something similar for steam engine.
While black paint does absorb heat, I suspect that the reason it did not help is that copper is such a good conductor of heat, that the heat absorbed is carried inward (toward a cooler part of the pipe), and transferred to the water. As long as the outer surface of the pipe is hotter than the inner surface, the heat will flow inward.
Also, while black is the best color for absorbing heat, it is also the best at radiating it. So unless it radiates all of it IN, toward the pipe, the effect would indeed be negligible.
Question..... do you have any data on a max temp at a constant flow of, I’ll shoot low, 1 GPM? Standing water isn’t a usable resource. I understand this is a demonstration but it looks to me as if it’s being manipulated by showing this unit in a static situation. I would love to see a full scale unit in operation with the heated water being used. I guess I could make a cup of tea with this in an emergency.
Obviously, in order to be anything other than a novelty, the hot water would have to somehow be continuously pumped, as heated, into some sort of a reservoir tank. Then, when full, the system would have to know how to stop heating unless one wants an explosion. "Little" question, like that, make the difference.
Here's another tip - try using a candle flame to coat the copper pipe with soot to increase absorption. Over 20 years ago, I made a dish collector from a 1.2 meter diameter satellite dish coating with aluminum foil and later a mylar survival blanket which could be focussed using air pressure. After coating the bottom of a small pan with soot, it was able to make a cup of tea in about 2 minutes! If I had the capability then, I would have made a hollow carbon-blacked copper sphere to collect all the energy without any reflections, or make a hollow sphere out of thin copper tube. For a trough setup, a crescent-shaped pipe formed to capture reflections might be worth experimenting with!
Interesting if you need really hot water. However it cannot collect any more heat than what is collected by the size of the reflector. If you simply had black pipes covering the same area, the heat collected would be the same?
Wondering what you would recommend as a simple insulated hot water storage item that is only about 5 -7 gallons? Lots of off grid van dwellers or bushcraft folks could use this sort of heater and store water to cover a 12 hour period. 24 hours would be even better. They could mix cool water with the hot water to use for many applications.
It's not boiling, because you're only measuring the hottest part of the water, which will float to the top of the pipe. In order to get it boiling, all of the water needs to reach about 99 °C. But if that would happen, most of the water will just shoot out of the pipe. Just like when boiling water in a testtube. Nice idea though. If you know the exact amount of water and the temperature rise over time (you need to empty the water into a cup for this, to get precise readings of the temperature), you can calculate the heating power.
On another day when I was not shooting video, and there was no wind cooling the pipe by blowing over it, the water did reach boiling, I could hear it bubbling in the pipe, and see a few drops of water splashing out the top.
I understand not going to the extra trouble to enclose the pipe or glaze the entire apparatus. What I don't understand is why you didn't bother to paint it black, which would have been very simple, and would have increased temps significantly.
Why isn't it used broadly? Because it works only in summer - that's 1/3 of the year. And you need your own roof for the installation, which means you can't have it if you live in an apartment.
Great video. I too am interested to understand whether concentrating solar energy in this way can be used to heat the air in an enclosed cabinet that can then be pumped to cold indoor areas.
Have you seen pictures of mountaint skiiers sunbathing with just swimsuits on the top of the mountains while air temperature is minus? Or just look stand behind the window on sunny days. For Canada is large - efficiency depends on latitude and time of year. But concentrated sun is powerfull.
just doing some really rough calculations it looks like you're getting 150btu/hr out of this example. Pretty cool for such a simple and small design. my math: 6 secs to rise 1 deg = 10 deg/min = 600 deg/hr 600 deg/hr = 600 btu/hr per pound of water 1/2 cup of water = .26lbs of water 600 *.26 = 156 156 btu/hr
Only works in hot sunny conditions though. I think evacuated tubes are a much better solution. You can buy the tubes now and build your own heat exchanger. Think your idea is nice though for hot water but in hot countries only.
Thank you for a good video. Can you show how to use this in a thermosyphon? (sp?). If you can heat a drum of water with this, I can see possibly heating a house with it.
You commented a long time ago. I've thought about a heat sink of some sort and then draw domestic water from it as it circulates through. I'm seeing some channels showing this method and it's working for the homeowners. My issue is that a lot of them like this channel do not reply to comments which becomes frustrating. Have you tried the set up or did you put it on hold?
A proper demo should have included a pipe in the same setup without the reflector...because a copper pipe on its own would seriously heat a 1/2 cup of water
No, the heat of the sun on metal objects can raise them to very high temperatures without a reflector. One example is the way that the padlocks on my allotment shed get so hot in the summer that I can't handle them without gloves. Garden hose laying in the sun get so hot that the water emerging from it steams. Of course a reflector increases the heat input, but with a large area of solar collector and strong sunshine you can reach temperatures which are more than enough for typical applications.
***** Wrong: the hose lies on a dirt path. It is a statement of the blindingly obvious to remark "As soon as you put more cold water in the hose it will cool the hose." And it's not a great deal more informative to say that by adding a reflector you can capture more energy. Duh.
***** "the heat of the sun on metal objects can raise them to very high temperatures without a reflector." Take for example the bonnet of a car (a dark colour shows this effect strongest). In an area of intense sunshine it too will get uncomfortably hot to the touch. I have given practical examples from my own experience. For water heating with a garden hose, you will find many TH-cam videos. If you choose not to believe me, tough luck.
Ok, folks. Stay on-topic, and keep it reasonably civil. Otherwise I will have to start editing, and I really do not want to do that. This comment was aimed at off-topics that were deleted.
This system is for water. Soda cans are not able to withstand typical water system pressures. However, I did build an air heater using soda cans. Video to come.
If the whole point is to show how effective concentrating sunlight is, why wouldn't you test it along side a copper pipe without the reflector? Based on what we see in the demo, for all we know a plain copper pipe would have gotten just as hot in the sun.
100ml (half of a cup) 1 degree F each 6 seconds - so around 1 degree C every 10-11 seconds gives me roughly 1 kcal each 2 minutes for 2 sq feet. Its 80W (4,19J/s is one cal/s if i remember correctly) Albedo of the sun in troposfere i think is around 800W/ m^2 soo... roughly computing 150W / 2 ft^2 so 50% of efficiency is quite a good achievement :)
it will operate at peak efficiency during the middle of the day. the early morning and late afternoon will only be at 1 tenth of the solar exposure during the middle of the day
You are correct but if you position the reflector to catch the suns rays at the maximum point of the day, the remainder each side of maximum will be a ramp up to maximum then a tailing off to minimum. During the cycle of the day with a good sized system this will be more than enough to give a days hot water for a domestic system in a sunny climate. There are many systems of this type on roofs in Spain. The rate either side of peak efficiency is not 1 tenth of the exposure, as the sun travels across the horizon the efficiency increases to maximum (peak) then slowly tails off. This can be improved some with a tracking device that moves the assembly into the peak throughout the day.
Just happened to watch this your project. Why don't you give dimensions and measurements of parabola, pipe, etc. It would help and make easier for DIYers and help to impoeve and may be get higher temperatures.
OK so I'm being picky but the Earth doesn't really ''move'' its in relation to the Sun and its axis... so seeing the Earth moving back and forth looked odd. But your Solar concentrator?/ awesome.. really good. Brilliant in fact. OK. Yep You're right. Left Me hanging. got a very hot water pipe.. now what do I do with it and how can I heat more of the stuff!
The earth moves around the sun in an orbit, but as we travel through the solar system we never actually go in a circle around the sun, its more of a spiral, a set distance from the sun. As this happens, the Earth also "wobbles" on its axis and tips toward and away from the sun. This creates the seasons as the sun points its concentrated rays on different positions of the earths surface. It is why when the Northern hemisphere has summer the Southern hemisphere has winter. This is the movement that is mentioned, and is not in relation to the Suns axis, its the Earths axis that changes position.
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Thanks for posting. In 1970, I build one of these for a science fair project. I elevated the storage tank (a 5 gallon metal can) and used thermal convection to circulate the water. Worked great and was a great demonstration of solar water heating on a budget. The whole device cost less than $20 to build and was a fun project.
That was my exact thought using thermosyphon. The Mother Earth News featured a similar set up recycling a refrigerator box.
For some reason I had a problem getting mine to circulate by convection.
Once the water boiled it caused pressure in both directions within the pipe and would just repeat with no circulation
@@drd1924 The tank has to be elevated above the top of the collector. The water should never boil. The size of the hot and cold pipes to the collector should also be of sufficient girth to allow unrestricted flow between the storage tank and the collector. I won the 6th grade science fair with mine. I was 12 years old then. Enjoyed the heck out of building it. I still have the collector that I built in 1970!
@@winfordnettles3292 Gotcha, thank you sir....Perhaps my pipe size was too small to allow sufficient flow for exchange...Will try again. I was also thinking of installing a check valve to ensure proper flow direction should boiling occur
@@drd1924 "Check valve"
In Australia, 80's. There was a same system unit called 'Suntrac'. Had 2 reflectors, about 5ft long, 2-3 ft wide. Tank on the top, clear covers, and a water pressure tracking system. The centre pipe was sealed with a gas inside, this pulsed the heat into a sealed end bulb within the tank. Worked well.
Thank you for taking the time to put this together. While there are lots of interesting comments, know that I found you while looking for examples of how to heat just over a cup of water to use in my Aeropress. I don't need a capacity of more than one cup, so this solution is among the tops. We're soon to be full time RVers, and want to figure out unique ways to conserve LP/electric. Thanks again! :)
props
In the '80s........I had a house with two four by eight solar panels in Massachusetts......... With one sonny day it gave me 160 gallons of hot water..... Heat exchanger, recirculation pump, anti-freeze.........it was all a great idea and savings..........this system looks to be more compact, and more efficient.
Thanks for sharing.
I though about this concept a few years back. I can see that it works! What I was also thinking was, since I live in a tropical country we have great exposure to the soon through the year, so I was thinking that it might be possible to reach boiling point with a little bit more industrialize set up in order to be able to get salty water from the sea and take the salt out! It could be inefficient but the sun is free so...
a donut ring of seawater, the vapor dripping from an upside down cone in the donut hole to the freshwater container underneath, the tide refilling the seawater part, solar power to provide electricity to pump the fresh water up to a roof tank
1) Build parabolic mirror similar to the size in this video.
2) Install a clear glass oven pan with sea water in the pan.
3) The sea water will evaporate and rise as steam.
4) That steam is pure water.
5) Instal a thin sheet of clear acrylic a few inches above the pan. But angle the acrylic so that the steam droplets which gather on the àcrylic will slide down the surface of the acrylic and fall off into a separate pan.
Voila! Clean water.
FYI, that type of Pyrex measuring cup is made from soda lime glass. Rapid temperature changes, such as pouring boiling water into it, can lead to violent shattering of the glass.
Cool demonstration though! Thanks for sharing.
Very nice idea, and well explained. It has got me thinking. Also thank you to Pete's idea of painting the pipe black.Thank you.
I am really grateful for your precious time, used in this demonstration video of this simple and at the same time so fundamental and important for the development and improvement in our homes, not to mention the economy with the consumption of electric energy, and not to mention that the steam of water can also be used to generate mechanical and electrical work, through a hot air engine using a coil for example. congratulations and thank you very much. big hug my brother
Back in the early 80's I worked for a company who installed this type of hot water system in Nevada. Pre built 8" long parabolic collectors with blackened copper pipe set into an aluminum framework on the roof of the house. the system had a sun tracking feature that kept the collectors facing in the optimum direction while set at the best average angle to the sun for the latitude. This was a closed loop system. Meaning no household water entered the system. The system water was pumped through a heat exchanger tank and back up into the collectors. The house hold water passed through the heat exchanger into a storage tank and then into the existing hot water heater and into the house. This method allowed the existing system to be isolated in case of emergency. On many occasion during initial start up I watched thermometers go from ambient air temps of 50 degrees F to over 250 degrees F as fast as the needle could move. As the system would run this temp would come down to a more reasonable 200 degrees f. The normal operating temp of the system was designed to keep the household water in the 105 to 115 degree range. This technology should and needs to be utilized more these days.
Pretty trick for the 80's, especially having Sun Tracking with no laptops
@@drd1924 The tracking feature was simplicity at it's best. There was a photovoltaic eye that had a small riser held above it essentially dividing the eye in two. as the sun moved (earth rotated?) and exposed the eye to sunlight a small motor connected to a chain drive would activate moving the collector just slightly to re-shade the eye and stop the motor. The riser was flat on the bottom and half circle on the top this allowed the eye to catch the correct amount of sunlight throughout the year without adjusting it.
@@NVOutsider Very creative!, Thanks for the explanation
I figured it had to utilize some sort of CDS cell, whats puzzling me is...
Did it know to reverse directions in the morning to start over or did it have to be reset every day?
@@drd1924 the riser piece was 1/16" to 1/8" thick painted white aluminum. It sat directly over the center of the eye. so when the sun set the collectors stayed facing west as the sun hit the eye in the am everything would rotate to the east and start the process over. I have a feeling my explanation is really dumbing it down due to my 18 yo lack of understanding and it being about 40 years ago. The system was manufactured in Arizona by a company called USMC (?)
What is a "CDS" cell?
@@NVOutsider Hi, A CDS Cell is short for
Cadmium Sulphide (a light controlled variable resistor, The Photoeye)
Thanks again for further explaining, rotating would make more sense. I was picturing the mechanism Panning and could only think of using limit switches to stop the movement and reset it. But simply rotating would simplify it even further...Very Cool
Well not with the prices going tenfold in a few months this will become very very relevant. Thank you for your great video. I have about 16 months to master how to use alternatives for heating our house. I found already some very usefull stuff.
Mount this below a water tank, then allow convective circulation to heat the water in the tank by day, then by night, the heated water will stay elevated in the tank.
Likewise, make another radiator, but mount it above a second tank, to cool the water by night with convective circulation, then by day, the cool water will stay low in the water tank.
This way, you have both hot and cold water available.
Thank you for this comment.
Thanks for sharing practical scalable DIY tech that anyone who's sat in a car on an overcast winters day could understand the principal being demonstrated. Thanks nice modular system.👍😊
I built one like that in 1964 about 59 years ago. When I was a teenager. Got very hot, steam.
I built one of these for a science fair project in the late 1970's. I painted the copper pipe black, which made it heat up a lot faster than the bare copper.
This is great! I wonder how much difference it would make to paint the pipe a flat black, just a thin coat, maybe with BBQ or exhaust system paint, or if oxidized copper is sufficient?
Use a horizontal arc that way it always point at the sun, the double curve is harder to make but doable with a flexible material, or just section and angle the sections to follow. This obviates the need for tracking. Also paint the pipe with flat black high temp. engine paint, so you get more frequencies absorbed.
I wonder if we could use the system to heat a working fluid so it could expand and push a hydraulic piston to follow the sun? My idea was to use the heat from solar panels to automate their turning.
@@fajile5109 "Sterling engine" use the heat from the sun and the cool from the collectors shade.
Very nice in summertime
Heating the pool ?
I bought a vacuum tube commercial water heater. Free hot water all year round (with a little gas assist in winter).
Very informative video. It is great that the use of copper is limited to one central pipe vs a long copper coil or multiple parallel copper pipe collector as copper is expensive. While glass mirrors would reflect more solar energy mirror polished stainless steel sheet metal would likely be more cost effective. Solar concentration is a great technology but it does have some drawbacks to be usable for the lay consumer. Boiling in a water heating system is not ideal as pressure builds up and could cause bursting issues. There would have to be some type of circulator, heavily insulated HW storage tank, temperature monitoring device, and a device that will shut off the circulator when approaching the boiling point of water as well as to rotate the collectors out of the sun. Also having to manually adjust the angle of the unit every few days is not feasible there would have to be some type of mechanical unit to pivot the collectors.
if you lay it east-west it will always be pointing to the sun
It felt like I was watching the discovery channel. Great narration.
I could be misremembering my college physics, but it's not a coincidence that it stopped at the boiling point of water. It stopped there because the water was boiling. Liquid water can't get hotter than the boiling point. All the energy going into the pipe was going into producing water vapor. After all the water boiled off, the pipe would start getting hotter. It might have melted the copper eventually.
It would be interesting to know how big a reflector you'd need to heat a water heater full of water from say 70 F to 160 F over the course of a day.
Thanks for an inspirational video.
I nearly got it correct, I have the parabola built.
I have not yet put the copper pipe in.
All my experiments to date have not worked for a couple of reasons:
1/ no copper pipe (WHAT I have to have a pipe at the apex of the parabola?) (Answer: DUH!)
2/ not a shiny surface. (Unsure what material I used, I think is stainless steel)
All that said, my construction is very similar to your, except I do not have a center support, but it is very ridgid.
Loved the safety comments, like don't pick it up by the pipe, err sorta been there done that. (think, wet paint DO NOT TOUCH)
Thanks mate
A good solar still easily reaches 50°C under sunlight and offers pure, hot water. An autonomous, off-grid user doesn't need those expensive solar hot water panels. Just a plastic sheet and a pump is enough :-) .
For any readers here, at point 1:30 the pipe sizes is shown as 1/2 inch copper fittings.
And that is why the temperature wasn’t going any higher. That water that was steaming/evaporating was taking a substantial amount of heat with it...
my Grumman Sun Stream solar water installed in 1978 COOKE water for thirty years before the A O Smith stainless steel tank began leaking. The optimal tilt is 37° , I had 45° in my location. on Dec 21 , a partly dsy, the late afternoon tank temp was 97°. 80 gallons of warm water when the incoming temp was 52°.
Cost with tax credit: 1695.00
Install labor 350
antifreeze replace 300
total cost $2445
reduction in electric bill was over 200 kwhr per month
200 kwhr yearly or $240.00 per year electric cost
80,000 lbs of pollution !
A hybrid water heater cost $1395.00 and will reduce electric bill almost as much as the solar water heater.
At 4:10 - On an annual basis, the Earth's tilt remains constant. The changing angle of sunlight is due to the Earth's orbit around the Sun.
If you install one way check valves the heat of the water will propel the water through the pipes/hose on a continuous flow. And I agree painting the copper pipe black will increase it's effectiveness and will draw the water from a tank or vessel and pump it into another tank or vessel.
This can heat fluid to circulate in hydronic heat system, too…putting 1-way check valves moves the hot water in the direction wanted, so it can recirculate.
Can also use thermostat to control it. Needs an expansion tank also.
But it’s a fairly low-tech system that can work even in winter, as long as there’s enuf size to system, & cloud reflectance.
A backup small tank water heater can also be in the loop, for dim days & nites.
how many feet of copper would it take for an average sized family house. Using hot water sparingly. great video!!!!
You should narrate unsolved mysteries
Raulduke duke
Anybody remember spooky voiced Vincent price .?. Would love to have heard him say..autogyro.. 😊
Raulduke duke r
Qm
Thanks for posting ---all facts--very impressive---I have experience of 150 degrees C
Great 👍
I really appreciate such a nice n practical efforts .In the greatest interest of mankind across the globe
This can be implemented across regions where there is no access to electricity, I hope social conscious young men like you can provide this system at minimum cost or for free to people in need. Thank you for your interest.
Would it not be better to paint the pipe flat black?
Your video was perfectly presented. So very informative.
The three words " some assembly required " doesn't scare people away from projects like this. It's " government taxes everything".
hit the nail on the head, OLE!
I am assuming that you would need a water expansion system for the hot water. Also, I would use a glycol of some sort instead of water to prevent freezing in winter.
How about a large insulated heat sink to preserve the heat. Have the tubing to the house run through the sink to absorb the heat and distribute either to the domestic hot water or some form of radiator set up. I'm looking at our mountain house and trying to keep the energy bills low enough so that I don't have to sell it with the prices of power these days.
This reminds me a lot of the solar air heater. It looks good with static air. But once you start cycling air through them, you find they have a very low capacity to heat a volume of air. I suspect the same is true with your solar water heaters.
Would blackening the pipe add efficiency ?
Could you make a return pipe e.g. behind the mirror and a reservoir on top using thermal circulation to heat a larger volume ?
The technic is called "solar collector" and is much more effective to heat up water directly as solar cells - where the flat collector have lower efficiency than tube collectors, even at low outside temperatures.
odd that he makes no mention of locating the copper tube at the focal point.....duh.....
Would like to have seen if that device could heat running water THROUGH it, to actually know if it is feasible to install into an off-grid water system! Putting a half cup of water into ANY metal container, out in the sun, even without a parabolic refractor, would still heat the liquid!
Imagine a connecting the bottom to a small plex hose that goes to a small cup reservoir elevated to the just below the top of the solar exposed pipe when elevated as in the video. As water evaporates/boils away at the top, new cold water is gravity fed into the bottom from the reservoir. Helping keep water throughout the solar exposed pipe for maximum heat transfer. Then one can use the steam given off at the top to cook food in an insulated steam box.
I think i came up with a one way heat diode. My idea is that id have a few energy collectors and a heat battery. Have them dump the excess heat into the battery. Otherwise it would just heat up a water heater. Or it would heat up a air dryer. I have an idea for a filtration system that uses water instead of expensive filters. I haven’t figured it out yet but ive seen the system used in paint booths. I just need to dry the air after it comes out or it would grow bacteria eventually. Also we can use our waste stack as a heat dump. I was thinking we use our sewer as a geothermal heat dump. So the first goal is to generate an excess of heat. That way i have enough of a heat differential to generate energy. Once the heat battery is hot enough for steam its a wrap free power from nature with just maintenance or what ill do is select materials that need almost no maintenance. Actually im thinking of making a open source youtube series on what i think the perfect house would be. With some help i believe instead of a net zero house we can make a -100% house. With it capable of absorbing and holding nearly every pollutant humans make and turning it into a clean energy. With the filtration system i mentioned we would be cleaning the air we take in from the outside of road dust and other fine dust pollutants. We would have a cooling effect on the ground similar to the shade a natural forest would have. (Thermal pollution a theory i came up with in 2010.) and most importantly and obviously provide energy instead of take energy.
Not paint pipe black no ?
Any needing a description of how a water valve works probably doesn't have the skills to do this.
How much water you producing with that little thing? When the power is off I have laid black garden hose in the yard and fill it with water and let it stand for a bit. Gets pretty hot. Won’t boil but hotter that you can stand.
I am going to try this to heat my water supply with this unit. Do you have any recommendations from yourself or TH-cam videos you think are worth looking at and executing on that information Sir ??? Thanks
Thank you so much, i was looking for this for a while
Why not paint the pipe black?
All these solar panels sitting on top of homes have lots of heat. All that heat reduces the panels life and efficiency. They need to be sealed then water induced. Thus providing free electricity & hot water without depleting your electric reserve.
I've done it on a small panel. Used a parabolic dish to focus the sun on the panel. Then ran water through it. Resulting in tripple the electric output~!
Just a suggestion, wouldn't it be better to have the reflector support on the outside? Because when there's those wooden things inside, the shade from each would decrease the overall temperature as sun rotates?
I'm about to build something similar for steam engine.
Would have liked to see the copper pipe painted black to see the difference. Very good video though. Thanks.
I did blacken the copper pipe to see if I could get additional temperature or a faster temp rise, but it appeared to have a negligible effect.
While black paint does absorb heat, I suspect that the reason it did not help is that copper is such a good conductor of heat, that the heat absorbed is carried inward (toward a cooler part of the pipe), and transferred to the water. As long as the outer surface of the pipe is hotter than the inner surface, the heat will flow inward.
Also, while black is the best color for absorbing heat, it is also the best at radiating it. So unless it radiates all of it IN, toward the pipe, the effect would indeed be negligible.
A small portable version of this could be used in the garden to deliver scalding water to kill weeds
Question..... do you have any data on a max temp at a constant flow of, I’ll shoot low, 1 GPM? Standing water isn’t a usable resource. I understand this is a demonstration but it looks to me as if it’s being manipulated by showing this unit in a static situation. I would love to see a full scale unit in operation with the heated water being used. I guess I could make a cup of tea with this in an emergency.
Obviously, in order to be anything other than a novelty, the hot water would have to somehow be continuously pumped, as heated, into some sort of a reservoir tank. Then, when full, the system would have to know how to stop heating unless one wants an explosion. "Little" question, like that, make the difference.
Covering the assembly with clear plexiglass or glass to incase it will drive temperatures up even more. Like a greenhouse effect.
True, and it's mentioned in the video.
Thank you.
Here's another tip - try using a candle flame to coat the copper pipe with soot to increase absorption.
Over 20 years ago, I made a dish collector from a 1.2 meter diameter satellite dish coating with aluminum foil and later a mylar survival blanket which could be focussed using air pressure.
After coating the bottom of a small pan with soot, it was able to make a cup of tea in about 2 minutes!
If I had the capability then, I would have made a hollow carbon-blacked copper sphere to collect all the energy without any reflections, or make a hollow sphere out of thin copper tube.
For a trough setup, a crescent-shaped pipe formed to capture reflections might be worth experimenting with!
Soot is actually an insulator. For best results, the pipe should be chemically blackened.
Spherical reflectors make for very good cookers.
What chemical?
What's the heat transfer to flow rate?
Thanks for the vid!
Love the dramatic music behind such an otherwise mundane topic.
Interesting if you need really hot water. However it cannot collect any more heat than what is collected by the size of the reflector. If you simply had black pipes covering the same area, the heat collected would be the same?
Gluing the reflector would make a better reflection right?
cuanto tiempo le tomo en alcanzar su temperatura final? . de que tamaño es el concentrador
You read my mind :) - good mastering and montage
that bloody music
i didn't notice till i saw vid a second time
by the way he's on another channel singing. Get on Your Horse (And Ride) - Randall Weatherington the sun fried his brains
Just mute and turn on captions
@@kmw4359 I thought the music was genius.
And the wood directly stick on the reflector… enjoy the fire soon!
What is needed to size it up to make it practical. Say enough water to have a shower?
Wondering what you would recommend as a simple insulated hot water storage item that is only about 5 -7 gallons? Lots of off grid van dwellers or bushcraft folks could use this sort of heater and store water to cover a 12 hour period. 24 hours would be even better. They could mix cool water with the hot water to use for many applications.
RV water heaters are 6 gallons , maybe one from a wreck
Drill ports on a cooler storage water in the cooler
I wonder if it could be used for a Livestock tank defroster...
Amazing, wish you would have made more videos about this subject
Nice demonstration and explanation. Thanks for the video.
Maybe paint the pipe black too
See comment about this.
What comment? Where?
Pete's Shredder.
Buried in the comments.
I did blacken the pipe with negligible results.
Black coverings will absorb some of the heat needed to hit the copper. Not a good idea for highest efficiency.
Great stuff man , thanks for the post.
Paint tube black? Performance at winter temps? Use anti-freeze circulated via pex to heat tank?
Coating the pipe with black soot might help. Connect a heat engine to it to generate electricity.
impressive demonstration of principle.
Steven Carpenter m
It's not boiling, because you're only measuring the hottest part of the water, which will float to the top of the pipe. In order to get it boiling, all of the water needs to reach about 99 °C. But if that would happen, most of the water will just shoot out of the pipe. Just like when boiling water in a testtube. Nice idea though.
If you know the exact amount of water and the temperature rise over time (you need to empty the water into a cup for this, to get precise readings of the temperature), you can calculate the heating power.
On another day when I was not shooting video, and there was no wind cooling the pipe by blowing over it, the water did reach boiling, I could hear it bubbling in the pipe, and see a few drops of water splashing out the top.
Morton's painting the pipe black increase the temperature somewhat
I understand not going to the extra trouble to enclose the pipe or glaze the entire apparatus. What I don't understand is why you didn't bother to paint it black, which would have been very simple, and would have increased temps significantly.
Did I miss something?
Where do you find the focal point of the mirror?
DIY - Thank you for your efforts and Vids!
Why isn't it used broadly? Because it works only in summer - that's 1/3 of the year. And you need your own roof for the installation, which means you can't have it if you live in an apartment.
If you connect this to a hot water holding tank, then add a Stirling engine to the top of the tank, you get even more from the setup
Great video. I too am interested to understand whether concentrating solar energy in this way can be used to heat the air in an enclosed cabinet that can then be pumped to cold indoor areas.
Theoretically, yes.
I would like to see a test made in Canada when the temperature is minus 25 degrees Celsius. Has there ever been anything like that done before??
Have you seen pictures of mountaint skiiers sunbathing with just swimsuits on the top of the mountains while air temperature is minus? Or just look stand behind the window on sunny days. For Canada is large - efficiency depends on latitude and time of year. But concentrated sun is powerfull.
just doing some really rough calculations it looks like you're getting 150btu/hr out of this example. Pretty cool for such a simple and small design.
my math:
6 secs to rise 1 deg = 10 deg/min = 600 deg/hr
600 deg/hr = 600 btu/hr per pound of water
1/2 cup of water = .26lbs of water
600 *.26 = 156
156 btu/hr
Only works in hot sunny conditions though. I think evacuated tubes are a much better solution. You can buy the tubes now and build your own heat exchanger. Think your idea is nice though for hot water but in hot countries only.
Thank you for a good video.
Can you show how to use this in a thermosyphon? (sp?).
If you can heat a drum of water with this, I can see possibly heating a house with it.
Theoretically, yes.
You commented a long time ago. I've thought about a heat sink of some sort and then draw domestic water from it as it circulates through. I'm seeing some channels showing this method and it's working for the homeowners. My issue is that a lot of them like this channel do not reply to comments which becomes frustrating.
Have you tried the set up or did you put it on hold?
@@beebob1279 I am weighing options for a later date.
Thanks for getting back with me.
Splendid idea! Love it
A proper demo should have included a pipe in the same setup without the reflector...because a copper pipe on its own would seriously heat a 1/2 cup of water
No, the heat of the sun on metal objects can raise them to very high temperatures without a reflector. One example is the way that the padlocks on my allotment shed get so hot in the summer that I can't handle them without gloves. Garden hose laying in the sun get so hot that the water emerging from it steams. Of course a reflector increases the heat input, but with a large area of solar collector and strong sunshine you can reach temperatures which are more than enough for typical applications.
***** Wrong: the hose lies on a dirt path. It is a statement of the blindingly obvious to remark "As soon as you put more cold water in the hose it will cool the hose."
And it's not a great deal more informative to say that by adding a reflector you can capture more energy. Duh.
***** "the heat of the sun on metal objects can raise them to very high temperatures without a reflector." Take for example the bonnet of a car (a dark colour shows this effect strongest). In an area of intense sunshine it too will get uncomfortably hot to the touch. I have given practical examples from my own experience.
For water heating with a garden hose, you will find many TH-cam videos.
If you choose not to believe me, tough luck.
Ok, folks. Stay on-topic, and keep it reasonably civil. Otherwise I will have to start editing, and I really do not want to do that.
This comment was aimed at off-topics that were deleted.
What is the length of pipe required to boil 1 liter water in this method please
very inspiring video.. I would also like to see if whats the most effective using soda cans or this copper pipe..
This system is for water. Soda cans are not able to withstand typical water system pressures. However, I did build an air heater using soda cans. Video to come.
really? when is that video coming out?
If the whole point is to show how effective concentrating sunlight is, why wouldn't you test it along side a copper pipe without the reflector? Based on what we see in the demo, for all we know a plain copper pipe would have gotten just as hot in the sun.
Awesome video, First time iv'e heard of Parabolic and truly interested in learning more about it. Could this method be used in making hot air ?
Theoretically, yes.
100ml (half of a cup) 1 degree F each 6 seconds - so around 1 degree C every 10-11 seconds gives me roughly 1 kcal each 2 minutes for 2 sq feet. Its 80W (4,19J/s is one cal/s if i remember correctly) Albedo of the sun in troposfere i think is around 800W/ m^2 soo... roughly computing 150W / 2 ft^2 so 50% of efficiency is quite a good achievement :)
Is it more effective than black background?
Thanks for posting. for flowing hot water I assume you add the necessary plumbing?
Correct.
Also much, much more pipe. Flowing cold incoming water will cool the pipe fast.
Nice work.
What reflective material did you use?
it will operate at peak efficiency during the middle of the day. the early morning and late afternoon will only be at 1 tenth of the solar exposure during the middle of the day
You are correct but if you position the reflector to catch the suns rays at the maximum point of the day, the remainder each side of maximum will be a ramp up to maximum then a tailing off to minimum. During the cycle of the day with a good sized system this will be more than enough to give a days hot water for a domestic system in a sunny climate. There are many systems of this type on roofs in Spain. The rate either side of peak efficiency is not 1 tenth of the exposure, as the sun travels across the horizon the efficiency increases to maximum (peak) then slowly tails off. This can be improved some with a tracking device that moves the assembly into the peak throughout the day.
Just happened to watch this your project. Why don't you give dimensions and measurements of parabola, pipe, etc. It would help and make easier for DIYers and help to impoeve and may be get higher temperatures.
OK so I'm being picky but the Earth doesn't really ''move'' its in relation to the Sun and its axis... so seeing the Earth moving back and forth looked odd. But your Solar concentrator?/ awesome.. really good. Brilliant in fact. OK. Yep You're right. Left Me hanging. got a very hot water pipe.. now what do I do with it and how can I heat more of the stuff!
The earth moves around the sun in an orbit, but as we travel through the solar system we never actually go in a circle around the sun, its more of a spiral, a set distance from the sun. As this happens, the Earth also "wobbles" on its axis and tips toward and away from the sun. This creates the seasons as the sun points its concentrated rays on different positions of the earths surface. It is why when the Northern hemisphere has summer the Southern hemisphere has winter. This is the movement that is mentioned, and is not in relation to the Suns axis, its the Earths axis that changes position.
Good presentation, TQVM