Started planning my own off grid journey after far too long just dreaming. Think I have seen a couple of options on land which I am considering (Wales) I have loads of questions, came across your channel and wondered if I could pick you brain...so to speak? Do you know anything about mini hydro power, what do you use for power in the winter? Although consider myself fit, as a lady, don't really fancy lugging gas bottles about 😀. Learnt lots from your videos keep up the great work.
Got to love RUclips comments. It doesn't matter if your hobby is hand whittling Peruvian nose flutes out of unicorn horn, someone will tell you you're doing it all wrong! Love your set up, clear explanations and enthusiasm.
Actually Spencer, unicorn horn isn't a very good material for making Peruvian nose flutes. What you should use is bamboo as it has better resonant properties that are more pleasing to the human ear and require less airflow to generate sufficient output decibels and it's also more environmentally sustainable. I mean, everyone nose that!
It is amazing that you have so many solar and plumbing experts watching your channel.......who probably live on-grid in the city! Greetings from an off-grid home in Ontario, Canada
Or Bus mans holiday...When you do it all day, coming home to mess about with your own water supply loses its appeal. Convienence is the driver of the modern world.
‘More than one way to skin a cat’ So clever and resourceful to put these found thermal water panels to good use! I’d love to visit sometime and just tinker with systems with you.
Nice to see sunshine, green trees and hear summer birdsong. Cracking chicken whispering skills there, I've always had to chase the buggers. Make you laugh chicken's, funny old things. What is it about beards that aid cogitation? The organ behind you looks like the amazing mouse organ off bagpuss. Apologies for the random shit, your solar system was lovely too : ) BTW, what's the craic with Project Awesome? Was going to pop over and give you a hand in the Summer hols, you didn't get in touch and summer has gone. Keep up the good work, DA.
always watch you videos. I have wood burner central heating in my own house installed by myself gravity feed for hot water and pumped for rest of the radiators in the house best thing i ever did
What you do works for you - the fact your still here indicates your system is bug free, the size of your pipes are obviously ok as your system is very efficient, whilst every one has an opinion …… keep up the good work - ATB
It's been of great interest. I'd call that a resounding success :). The info and results about the insulation and lagging is great, showing almost 5 degrees saving. 20 degrees for probably the same price in total materials as I'd pay for 6 months energy and it's self sufficient bar a little tweaking as the seasons change. In 3 words: Simply bloody brilliant.
Sorry about the comment on the black paint on the panels. I m new to the channel and must confess I did not warched the first part of this. And yes, it must have been the colors of my phone display as I use my phone usually to watch youtube. Keep up the good job 🙏
Thank you for the update Max. I took a solar heating class oh so many years ago in college (don't ask how long) and here a while back someone was selling a group of panels on CL from the pictures they looked in good shape and if the funding had been there I would have been tempted. Currently mulling over a green house butted up against the house with a stack of black painted barrels to act as a trombe wall
Great to see it worked out. I always think it is nice to have panels at ground level like yours, it makes maintenance and cleaning easy. Mine are almost impossible to get to without a scaffold. I think it is easy for some people to get hung up on the efficiency of solar panel systems, it is always were remembering that solar energy is free anyway it is not like you are paying for anything once the initial infrastructure is in place.
An interesting experiment. I think that a key point is that its purpose is to contribute to providing hot water rather than to provide all of the hot water. Our modern life systems tend to shun multi-mode solutions which means that we miss opportunities, probably in many areas.
Hi Max, If you are still trying to attract a lovely lady via internet dating. I suggest the clip of you cleaning the carpet, plus the chicken in distress, would have ladies queuing to date you. If I wasn't probably the same age as your Mother, those clips would do it for me. Love Carol xxx ps Your Grandad was absolutely right about the whole Flushing Toilet thing.
I finally got around to making a solar air heater out of cans this summer, in Summer sun it was adding 30℃ to the air temperature. But now I need to plumb it into my workshop to see how it does with Winter sun!
I think you've done an awesome job, using what you have. Not having to light the fire so much in summer is a real bonus My only comment is that I would not throttle the water in the panels before they return to the heat exchanger. I think it would be better to heat lots of water a little bit constantly, rather than heat a little bit of water a lot and then dumping that through the system. I know this is how solar hot water systems work for heating pools, basically only trying to raise the temp a couple of degrees every time the water circulates through the system. Might be something to consider
Yep, I do let it run wide open normally, it's goes up to 40-45 degrees quickly that way but then slows right down. The throttling was just to see what would happen, if I tried to get the temp higher, maybe not explained myself very well there!
Awesome as that should be getting you the most efficiency out of the system. Russ while you are right about the amount of BTU's gained you have not taken into account heat transfer Generally speaking, the faster the flow rate the more efficient the heat transfer, but the efficiency has to do with the temperature difference between the heat source and the fluid being heated so there are diminishing returns at faster and faster flow rates. The rate of heat transfer between two points is a function of the thermal conductivity of the material between the two points and the temperature difference between the two points (and the amount of area of contact). A faster flow rate means the temperature of the water doesn't rise as much so that makes the rate of heat transfer somewhat higher. The fact that the amount of temperature rise is lower at the faster flow rate doesn't mean the water rises in temperature more slowly. On the contrary, it rises a little faster since more heat is transferred as noted above. If you lowered the flow rate in the system, the temperature of the water flowing through the panels would rise more but the amount of heat transferred would be somewhat less due to the lower efficiency of transfer in the panel due to the smaller temperature difference between the panel heat and the water (since the water is now hotter). If you want more efficiency of heat transfer, an even faster flow rate would be a little better.
Man I get so fed up of people telling you that things wont work, you must be sick of it. Seems to be working a treat. Have you put any thought into keeping bacteria at bay with a solar powered UV bulb steriliser (like from a fish tank)? Also to control your themo siphon, maybe use a thermostat mixing valve (used on showers to keep the temperatures constant if you have dodgy flow) They just close more when it gets cold, so would be perfect mechanical solution to keep the temps high.
Insulating those pipes likely will help greatly. A reflector on the ground will too. Especially on hazy days. My friends find that an adjustable sheet of aluminum or shiny white paint on wood can be tilted at the far end 3 to 15 degrees toward the collectors as needed.
I love this stuff! Still trying to figure out how we could follow in your footsteps money-wise, but just watching it for interest is entertaining in the meantime!
Yet another great info video! I would like to buy one of your herb choppers and Dave said would you ever consider a off grid tour/workshop so he could see stuff in person and pick your brain as we are going off grid next spring. Thanks Jo and Dave
Great video. Love your attitude.. the panels have seen , have a lot more pipework , I guess to slow the flow ? More heat exits ,? Keep up the great work..
Cool if you ever need a hand with anything i wouldn’t mind i would be grateful infact as I like learning new things about all the kind of stuff your posting videos about keep up the good work 👍
In terms of environmental impact/carbon footprint, the manufacture of the solar water panels must be much less damaging and easier to maintain in the long run. Looks like you've got things covered! Nice to hear your thought processes on how and why you did something in a certain way.
Nice one Max. This vid really cheered me up. Interesting that you couldn't really perceive the underfloor heating; possibly this will be more noticeable in the Winter? Suppose to get colder later in the week, so enjoy a nice cosy pint of Ale.
That was of interest to me trying to escape expensive energy bills in Sweden. I have to say its been interesting to watch some of your vids this evening. Makes a refreshing change to see a down to earth bloke telling it in simple terms. I wont ask how/if you got planning for that septic tank, im probably looking at a minmum 5k to sort that here. Jobs a goodun!
Another great presentation Max. Continue to cling to the "KISS" principle (keep it simple stupid)...a less complex, self-sustaining/regulating system increases quality of life ($$$ & time) even if there are loses in efficiency. P.S., if your PV panels maintain your electrical needs, then immersion heaters are a fabulous "dump load"...waste not, want not :)
Cool stuff, especially the Q & A round from minute 13 on. - Thank you. - How about making plans to combine solar heating circle with Viktor and Walter Schauberger´s water alive inventions ?
Using excess solar generation for heating water makes good sense. Once the batteries are charged you can't store any more, and if you can't use it all while its being generated than why not heat water?
Yes. The only thing I could think of is that maybe someone was (poorly) suggesting he use a heat pump water heater instead of a standard immersion heater.
It is common to use excess to heat water. They call it a dump load and some are heating 2000 gallons of water in underground storages. Dump loads can be all sorts of devices from grinding flour, heating water, charging an EV, and anything the owner can think up. There was a video around here somewhere a builder filled a basement with sand and pipe levels/tiers making a huge thermal battery. Don't let any extra go to waste it can all be used!.
FYI. In the late '70's, or maybe early '80's (?), I believe it was Texas A&M, that did a study on what colors absorbed heat best. Their conclusion was that a flat "pea green", very close to the color of your roof, was the best. Just thought I would toss that out there, in case there was someone that was on the verge of painting. Thanks.
Just one thought about slowing down the water through the solar panels. I used a 6kw water heater for the kids pop up pool a couple of years back and the pump pushed the water through so fast you couldn't tell any difference between input and output temp. I thought it wasn't working. On researching this I found that the heat energy is transferred to the body of water regardless of flow rate and the pool warmed as expected. Might be worth considering, so just an idea that might be worth an experiment (I didn't have a slower pump to check) Might save you some time. Great ideas though, keep em coming
If you want the heat to build in the panel before it dumps it's heat to the cylinder, all you need is a PRV on the flow & a non-return valve on the return to stop the heat expanding up the return line. I would try a low value PRV, say 1Bar. I would also add a TPRV (3bar) as a secondary safety valve. If you don't and the first PRV fails to open, you will have created a bomb. I would even go as far as to fit a third one on the return line before the non return valve (as it will be cooler there). As far as sanitising the cylinder, it's recommended to heat the cylinder to 60C degrees once a week. (air source heat pumps are setup to do this with an immersion heater).
Good video series, I like your approach. Interesting point about using solar electric with immersion heater would be your preference. I am designing a system for down in Dorset and was planning on solar thermal for the summer hit water. I will have to do the sums to see if the cost of PV panels Vs some cheap / second hand / homemade solar thermal panels.
What I think you need is a restriction on the inlet in the tank itself to allow the water to settle, maybe 2-3 layers of mesh domes would do it. You don't want hot and cold water to mix in a hot tank, that allows the water to pick up energy from the hot water on top, and recirculate it into the outdoor radiators, causing more loss in transmission to the solar collectors, and reducing the temperature difference between the collector tubes, and the water flowing through them. Your tactic of holding the water to allow pressure head to build is counter-productive, since it will cause more mixing in the tank, and increase the rate at which heat is lost to the surface of the collector enclosure.
Hi there , years ago i was very interested in building my own panels similar to yours i did take it to the extreme as i always do when researching a build and found out that it i vacuum sealed the panel and used a vacuum pump to remove as much air as possible the efficiency went up also i found that instead of black mat paint using powdered lead on the collector had the highest efficiency of heat collection into the copper sheet . hope this is food for thought for you. you could always try making an experimental panel from scratch
Insulate flow and return pipes of panels to tank. The thermal siphon will then only begin when the temperature of the panels exceed the tank. You need the panels to get to approx 5-10 degrees more than to tank to have a good effect of heating the water in the tank. Avoid all heat losses.
Yes, another video on this. Did you ever think of having a boiler box stove in the main room to feed the radiators? Or is it rather redundant as you have this in the kitchen.
I thought would be the case, cheers for the answer. Another question, what does it feel like to have a life that many people are envious of. Though it's hard work it seems like you have such a content and happy life.
Always considered flat plate collectors as a pre-heat system, topped up by back boiler and/or immersion heater. That was until I installed a tube system which is far far more efficient. Now I have no back boiler on the woodburner [getting more heat into the house] and very rarely have the immersion on. The system provides all the hot water I need for a couple of showers a day and all the washing up. As it runs at mains pressure It also feeds into the dishwasher and washing machine. In the summer I have to bleed off some heat on occasion. Tube systems rule IMO.
The cooler the panel temperature, the less the loss of heat to the environment - and the more energy you will get into the hot water reservoir...well that's the theory...hope that was worth commenting on!
Another great video. Thanks. This has me thinking. I am just about to do a modification to a 30sqm building to make it a live/work. It is not off-grid. It is a garden building 25m away from a house. The services will be trenched to it first. I have ruled out putting gas to it, as the regs are awkward. So, I will put water, electricity and comms to it. It will be airtight and have a small MVHR plant. I was thinking of heating it with electric underfloor and a wood burner for MVHR, and am toying with putting a water system under the floor as well as the electric. I am assuming I will need to plan the systems for this carefully, and that I need a heat exchanger with input coils to connect with the wood burner and possibly coils for a wet solar system. The main reasons I am doing this are to have a place to live in winter, which is cheaper to heat than the main house, and for when I am recovering from bouts of surgery, which I will have to endure at least another 5 times in the next 10-15 years. The house is really awkward for mobility, and modifications would be very difficult. I don't really want to move; it's a nice house. Looking at this statement, it all sounds a bit complicated. Realistically, maybe an airtight friendly free standing wood burner and the electric heating system will keep it simple and be adequate. It will be well insulated, so maybe I am over-egging it. If you have any suggestions, they'd be welcomed. Thanks.
You can vent any woodburner from outside (which is a good idea anyway to avoid drafts). If I was building again I personally wouldn't bother with underfloor heating, it takes too long to warm up and even though the slab is insulated the heat dosn't seem to store very well. The other drawback is that underfloor heating only really works well with a stone/concrete floor and I prefer the proper floorboards in the rest of the house! If you're expecting to have mobility issues, maybe consider a multi-fuel stove instead of a pure woodburner? Just thinking of the number of times, you'll be needing to refuel it. My kitchen range is multi-fuel and being able to run it for 12+ hours on one load of smokeless fuel is a real bonus in the depths of winter. It sounds like you're on the right track, thinking ahead is a v good move. I know what is like recovering from surgery - I sincerely wish you a speedy recovery each time.
I'd say lag the cold return-side also, it will cut down on losses, making the return-water going into the panels hotter, and this will in turn slow down the thermo-syphon a bit, but you are talking about having to throttle the valve anyway, so all in all, I think this will allow you to accumulate a higher final temperature at the end of each day. The thermo-syphon will be able to self-regulate the flow of water better.
I think you have done a great job.. like to see the system work. You say the flow rate is too high, so bends in the pipework can’t be an issue with yours? In fact if your thermo syphon is flowing too fast then lagging the return may be a good idea to slow it down. May even increase the output temperature and lowering heat loss too.. if it didn’t help it wouldn’t be a big job to take some back off anyway! Legionella is the worry with warm water hence get it to 60 degrees every 24 hours,, but people scare easily about this.. it takes about a week for water to turn stale and the issue arise anyway.. think your managing it ok .. 👍👍👍
On the subject of efficient use of PV to Solar Thermal (the guy could be right) if you've got 20% efficient panels and you are then using that electrical output to heat water, cut out the middle man and just go direct to solar thermal and reduce losses. Yes everything can be lost as heat, but electrical efficiency in generation and subsequent use does compound even if the end state you want is just heating anyway. Probably not so good in most of the UK, but in my place in Greece Solar Heaters are absolutely amazing for domestic needs.
Love the system, hope you find time & space for the solar tubes you had - I don't see why you couldn't just have rows of them on the wall to the left of these with their own thermo-syphoning system (maybe just run them parallel?). I feel the very minor improvements you could do to this system are either paint the exposed pipes from the panels black (to absorb even more solar heat) or insulate them (and really even on the return line). So long as a pipe is beyond the bottom of the system, it would be beneficial to paint black at the least. Regarding the return line... If the solar panels give say a 30 degree temperature increase, then if it's entering the panel hotter it will exit hotter. Also, having the pipes at the bottom of the system exposed will mean the water in those pipes can get even colder and will be harder to lift into the solar panels where it'll be heated.
Hello Max, I just discovered your channel and really enjoy your videos and I’ve just watched your Solar Hot Water series, great design, cheers. My only thought is if the exterior plastic pipe riser from the solar panels is resistant to the UV exposure and if it needs to be protected. It’s now 27 January 2022 and it looks like 4-years after you built it and released the videos so if there is a UV problem you might have discovered it by now. Thanks. Michael
Max please insulate every piece of pipework that is outside (and the return line inside as you say the thermosyphon is too strong anyway). You have seen a good improvement to temperatures by insulating your tank and I'm sure you'll see a similar improvement by insulating the rest of the pipework. Anything uninsulated outside is just leaking heat that could otherwise end up in your tank. That is my only criticism, great job and looks like the effort is paying dividends!!
Really enjoyed all your videos and explanations of how the system actually works. One question regarding you not lighting the range to heat water but how are you cooking?
I've been doing regular updates for patrons. I'm still in the process of upgrading it all, I may do an overall update video when (if) I ever get it finished.
That's very cool mate. Or, more accurately, hot! Are you ever going to try something with the posh evacuated tube hot water system you've got? It's probably not necessary given the results you've had.
Hmm 🧐 how happy are you with the heat exchanger in the tank could that be optimised for a better result it seems to me that everything revolves round the workings of that ! Just a thought that kept cropping up in my mind 👍👍💪
if you still have this system installed (with the range and the fire lit ) it might be worth putting a thermostatic switch (set at 95C) on the pipework somewhere so it turns on the underfloor heating pump to dump the heat into the concrete before the water starts to boil!! nothing worse than falling asleep in front of the fire and being woken up by the pipework banging and clanging as the water turns to steam
I have worked on designing controllers etc for solar PV and one of the issues is efficiency is lost when the cells get too hot. Energy from PV is not great for heating however this water heating type of system is significantly better and possibly the best system currently available for heating from solar energy. This leads to a question: how could the two be combined? IE a silicon PV panel (as GaAs is way too expensive at the moment) with water taking the heat from the cells and being used to warm the floor. That way you could potentially get significantly more power out of a panel than either system on its own. Not sure exactly how you could get even heat exchange on the panels but I'm sure someone could figure it out.
Would a smaller diameter feed pipe from the Solar panel help so heated water won't be drained off and get to the tank faster to transfer the heat in the tank? I'm late but enjoying your post. Yhank you.
I live on a boat I'm putting a couple of these pannels under my bifocal solar pannels and I know there are German pannels using more of the sun power on a smaller foot print... I love your keep it simple approach to things can I pick your brains about your underfloor heating are you available for work?
I made a video in the off grid living series all about heating in which I talk about the underfloor heating. As for work, I'm snowed under with my own thanks!
You and that clipboard have the ability to virtually sort any of Britain's energy problems today. Vote Max.
Started planning my own off grid journey after far too long just dreaming. Think I have seen a couple of options on land which I am considering (Wales) I have loads of questions, came across your channel and wondered if I could pick you brain...so to speak? Do you know anything about mini hydro power, what do you use for power in the winter? Although consider myself fit, as a lady, don't really fancy lugging gas bottles about 😀. Learnt lots from your videos keep up the great work.
I'm a plumber, if I ever pull out a thermal store or such like I'd happily donate it to you.
Got to love RUclips comments. It doesn't matter if your hobby is hand whittling Peruvian nose flutes out of unicorn horn, someone will tell you you're doing it all wrong! Love your set up, clear explanations and enthusiasm.
Actually Spencer, unicorn horn isn't a very good material for making Peruvian nose flutes. What you should use is bamboo as it has better resonant properties that are more pleasing to the human ear and require less airflow to generate sufficient output decibels and it's also more environmentally sustainable. I mean, everyone nose that!
The rooster stole this episode, that was awesome. The way he knew to come to you, and knew you'd help him.
that rug really ties the room together :)
I wish I had a quid for every time my husband has said that!
McBong's Lab
You forgot the "dude" : )
It is amazing that you have so many solar and plumbing experts watching your channel.......who probably live on-grid in the city! Greetings from an off-grid home in Ontario, Canada
Or Bus mans holiday...When you do it all day, coming home to mess about with your own water supply loses its appeal. Convienence is the driver of the modern world.
I admire your ability to dismiss idiots that can't comprehend the fact you don't need a pump.
Haha! I think it would be fun to see the interaction you have with you chickens & cockrel.
Great to see the clipboard back.
Kind to chickens good man.
‘More than one way to skin a cat’ So clever and resourceful to put these found thermal water panels to good use! I’d love to visit sometime and just tinker with systems with you.
I love the way you have made a lifestyle work and hope you inspire many people to cast off the shackles of corporate consumerism Well done :)
Nice to see sunshine, green trees and hear summer birdsong. Cracking chicken whispering skills there, I've always had to chase the buggers. Make you laugh chicken's, funny old things. What is it about beards that aid cogitation? The organ behind you looks like the amazing mouse organ off bagpuss. Apologies for the random shit, your solar system was lovely too : )
BTW, what's the craic with Project Awesome? Was going to pop over and give you a hand in the Summer hols, you didn't get in touch and summer has gone. Keep up the good work, DA.
Thanks, more Project Awesome coming soon, probs next video.
Handled the cockerel situation like a boss 😎
always watch you videos. I have wood burner central heating in my own house installed by myself gravity feed for hot water and pumped for rest of the radiators in the house best thing i ever did
Maximus Iron Thumper: Chicken Whisperer Extraordinaire. 💜
You have a wealth of knowledge and a pleasure to listen too, well done Sir.
What you do works for you - the fact your still here indicates your system is bug free, the size of your pipes are obviously ok as your system is very efficient, whilst every one has an opinion …… keep up the good work - ATB
It's been of great interest. I'd call that a resounding success :). The info and results about the insulation and lagging is great, showing almost 5 degrees saving. 20 degrees for probably the same price in total materials as I'd pay for 6 months energy and it's self sufficient bar a little tweaking as the seasons change. In 3 words: Simply bloody brilliant.
Thanks for sharing your experience with us! Always good to hear from someone who is actually using processes like this what does and doesn't work.
Always a pleasure to watch.One of the best You Tube Channels by far.
You are not only methodical but both a logical and lateral thinker. Bloody marvellous in short. I'm proud of you. X
good job and thanks for some helpful information. i am 5 years in on 5 acres. Devon, green because it rains all the bloody time.
Sorry about the comment on the black paint on the panels. I m new to the channel and must confess I did not warched the first part of this. And yes, it must have been the colors of my phone display as I use my phone usually to watch youtube. Keep up the good job 🙏
No worries, you're not the only one to think they look grey! I think it's the glass on them that does it.
Love your videos mate! I really want to live self sufficiently
Very glad it worked as you expected.
Thank you for the update Max. I took a solar heating class oh so many years ago in college (don't ask how long) and here a while back someone was selling a group of panels on CL from the pictures they looked in good shape and if the funding had been there I would have been tempted. Currently mulling over a green house butted up against the house with a stack of black painted barrels to act as a trombe wall
Great to see it worked out.
I always think it is nice to have panels at ground level like yours, it makes maintenance and cleaning easy. Mine are almost impossible to get to without a scaffold.
I think it is easy for some people to get hung up on the efficiency of solar panel systems, it is always were remembering that solar energy is free anyway it is not like you are paying for anything once the initial infrastructure is in place.
Thanks for the update Max, really appreciate it, and I'm so happy that it's worked! I hope it keeps your H20 warm this winter
An interesting experiment. I think that a key point is that its purpose is to contribute to providing hot water rather than to provide all of the hot water. Our modern life systems tend to shun multi-mode solutions which means that we miss opportunities, probably in many areas.
Hi Max,
If you are still trying to attract a lovely lady via internet dating. I suggest the clip of you cleaning the carpet, plus the chicken in distress, would have ladies queuing to date you.
If I wasn't probably the same age as your Mother, those clips would do it for me.
Love Carol xxx
ps Your Grandad was absolutely right about the whole Flushing Toilet thing.
Hear, hear.
I learn so many really useful things from you. All perfect for my basic life in my van. Thanks.
I finally got around to making a solar air heater out of cans this summer, in Summer sun it was adding 30℃ to the air temperature. But now I need to plumb it into my workshop to see how it does with Winter sun!
Good job! Keep up the quest.
I think you've done an awesome job, using what you have. Not having to light the fire so much in summer is a real bonus
My only comment is that I would not throttle the water in the panels before they return to the heat exchanger. I think it would be better to heat lots of water a little bit constantly, rather than heat a little bit of water a lot and then dumping that through the system. I know this is how solar hot water systems work for heating pools, basically only trying to raise the temp a couple of degrees every time the water circulates through the system. Might be something to consider
Yep, I do let it run wide open normally, it's goes up to 40-45 degrees quickly that way but then slows right down. The throttling was just to see what would happen, if I tried to get the temp higher, maybe not explained myself very well there!
Same amount of energy being put into the water. Idea is trying to find the balance to keep the flow.
Awesome as that should be getting you the most efficiency out of the system.
Russ while you are right about the amount of BTU's gained you have not taken into account heat transfer
Generally speaking, the faster the flow rate the more efficient the heat transfer, but the efficiency has to do with the temperature difference between the heat source and the fluid being heated so there are diminishing returns at faster and faster flow rates. The rate of heat transfer between two points is a function of the thermal conductivity of the material between the two points and the temperature difference between the two points (and the amount of area of contact). A faster flow rate means the temperature of the water doesn't rise as much so that makes the rate of heat transfer somewhat higher.
The fact that the amount of temperature rise is lower at the faster flow rate doesn't mean the water rises in temperature more slowly. On the contrary, it rises a little faster since more heat is transferred as noted above.
If you lowered the flow rate in the system, the temperature of the water flowing through the panels would rise more but the amount of heat transferred would be somewhat less due to the lower efficiency of transfer in the panel due to the smaller temperature difference between the panel heat and the water (since the water is now hotter). If you want more efficiency of heat transfer, an even faster flow rate would be a little better.
Great channel! Super helpful, thank you
Thanks for the update Max, very interesting. Largely self maintaining and in your case pratically free.
Great episode Max. Your homestead is looking wicked. As well as efficient.
You're my beard hero.
Also cool videos, nice to see what it takes to live the ~'offgrid' lifestyle :D
Man I get so fed up of people telling you that things wont work, you must be sick of it. Seems to be working a treat.
Have you put any thought into keeping bacteria at bay with a solar powered UV bulb steriliser (like from a fish tank)?
Also to control your themo siphon, maybe use a thermostat mixing valve (used on showers to keep the temperatures constant if you have dodgy flow) They just close more when it gets cold, so would be perfect mechanical solution to keep the temps high.
ratgreen yea mate anyone who's watched max's videos would know his system works well.
Insulating those pipes likely will help greatly. A reflector on the ground will too. Especially on hazy days. My friends find that an adjustable sheet of aluminum or shiny white paint on wood can be tilted at the far end 3 to 15 degrees toward the collectors as needed.
Hiya, you seem to have answered quite adequately what "some people" think, and fair doos.....
Max,Fanx for your vids mate, top geezer
I love this stuff! Still trying to figure out how we could follow in your footsteps money-wise, but just watching it for interest is entertaining in the meantime!
Looking forward to seeing if you can get much benefit in the coldest part of the winter.
i do love your content keep em coming!
How dare that chicken interrupt the great maximus iron thumper 👍👍👍😁 always good to watch your videos. Very entertaining 👍👍.
lazylad 90 he has his chucks tame hasn’t he,, never seen cockerel herding before.. Katie Cropper would be impressed...
I wish I was there. Sitting in the yard, listening to the birds. I never seen a chicken act like that.
Yet another great info video! I would like to buy one of your herb choppers and Dave said would you ever consider a off grid tour/workshop so he could see stuff in person and pick your brain as we are going off grid next spring. Thanks Jo and Dave
man this is fantastic . fitter by trade with a very old stone house in ireland youv given some great ideas and tips .
out of curiosity is the system all feeding into a single coil cylinder or multiple coil?
Shockingly Brilliant !!!
Great video. Love your attitude.. the panels have seen , have a lot more pipework , I guess to slow the flow ? More heat exits ,? Keep up the great work..
Cool if you ever need a hand with anything i wouldn’t mind i would be grateful infact as I like learning new things about all the kind of stuff your posting videos about keep up the good work 👍
Well done max,very interesting 😁👍👍👍👏👏👏
Max . You need a few dogs milling around there and you have the perfect set up , 🐾
He obviously has some pride in his living space
In terms of environmental impact/carbon footprint, the manufacture of the solar water panels must be much less damaging and easier to maintain in the long run. Looks like you've got things covered! Nice to hear your thought processes on how and why you did something in a certain way.
Nice one Max. This vid really cheered me up. Interesting that you couldn't really perceive the underfloor heating; possibly this will be more noticeable in the Winter? Suppose to get colder later in the week, so enjoy a nice cosy pint of Ale.
That was of interest to me trying to escape expensive energy bills in Sweden. I have to say its been interesting to watch some of your vids this evening. Makes a refreshing change to see a down to earth bloke telling it in simple terms. I wont ask how/if you got planning for that septic tank, im probably looking at a minmum 5k to sort that here. Jobs a goodun!
Another great presentation Max. Continue to cling to the "KISS" principle (keep it simple stupid)...a less complex, self-sustaining/regulating system increases quality of life ($$$ & time) even if there are loses in efficiency. P.S., if your PV panels maintain your electrical needs, then immersion heaters are a fabulous "dump load"...waste not, want not :)
St. Ironthumper. Friend of the animals
Cool stuff, especially the Q & A round from minute 13 on. - Thank you. - How about making plans to combine solar heating circle with Viktor and Walter Schauberger´s water alive inventions ?
Using excess solar generation for heating water makes good sense. Once the batteries are charged you can't store any more, and if you can't use it all while its being generated than why not heat water?
moth3rfck3r surely it is infinitely efficient since it is making use of a resource at 0 electricity usage if the batteries are full anyway!
Yes. The only thing I could think of is that maybe someone was (poorly) suggesting he use a heat pump water heater instead of a standard immersion heater.
It is common to use excess to heat water. They call it a dump load and some are heating 2000 gallons of water in underground storages. Dump loads can be all sorts of devices from grinding flour, heating water, charging an EV, and anything the owner can think up. There was a video around here somewhere a builder filled a basement with sand and pipe levels/tiers making a huge thermal battery. Don't let any extra go to waste it can all be used!.
Good info
FYI. In the late '70's, or maybe early '80's (?), I believe it was Texas A&M, that did a study on what colors absorbed heat best. Their conclusion was that a flat "pea green", very close to the color of your roof, was the best. Just thought I would toss that out there, in case there was someone that was on the verge of painting. Thanks.
Great video, i see you have a needy bird like most of us.
There was me thinking you'd use the pressure washer to clean the carpets :-)
Just one thought about slowing down the water through the solar panels. I used a 6kw water heater for the kids pop up pool a couple of years back and the pump pushed the water through so fast you couldn't tell any difference between input and output temp. I thought it wasn't working. On researching this I found that the heat energy is transferred to the body of water regardless of flow rate and the pool warmed as expected. Might be worth considering, so just an idea that might be worth an experiment (I didn't have a slower pump to check) Might save you some time. Great ideas though, keep em coming
+20 degC into the hot water tank. That is a good result, well done.
Yup, even 1 degree saves you energy.
Love to hear nature... Gorgeous, not you the sounds.. 👍
If you want the heat to build in the panel before it dumps it's heat to the cylinder, all you need is a PRV on the flow & a non-return valve on the return to stop the heat expanding up the return line. I would try a low value PRV, say 1Bar. I would also add a TPRV (3bar) as a secondary safety valve. If you don't and the first PRV fails to open, you will have created a bomb. I would even go as far as to fit a third one on the return line before the non return valve (as it will be cooler there). As far as sanitising the cylinder, it's recommended to heat the cylinder to 60C degrees once a week. (air source heat pumps are setup to do this with an immersion heater).
Good video series, I like your approach. Interesting point about using solar electric with immersion heater would be your preference. I am designing a system for down in Dorset and was planning on solar thermal for the summer hit water. I will have to do the sums to see if the cost of PV panels Vs some cheap / second hand / homemade solar thermal panels.
What I think you need is a restriction on the inlet in the tank itself to allow the water to settle, maybe 2-3 layers of mesh domes would do it.
You don't want hot and cold water to mix in a hot tank, that allows the water to pick up energy from the hot water on top, and recirculate it into the outdoor radiators, causing more loss in transmission to the solar collectors, and reducing the temperature difference between the collector tubes, and the water flowing through them.
Your tactic of holding the water to allow pressure head to build is counter-productive, since it will cause more mixing in the tank, and increase the rate at which heat is lost to the surface of the collector enclosure.
Hi there , years ago i was very interested in building my own panels similar to yours i did take it to the extreme as i always do when researching a build and found out that it i vacuum sealed the panel and used a vacuum pump to remove as much air as possible the efficiency went up also i found that instead of black mat paint using powdered lead on the collector had the highest efficiency of heat collection into the copper sheet . hope this is food for thought for you. you could always try making an experimental panel from scratch
Insulate flow and return pipes of panels to tank. The thermal siphon will then only begin when the temperature of the panels exceed the tank. You need the panels to get to approx 5-10 degrees more than to tank to have a good effect of heating the water in the tank. Avoid all heat losses.
Have you thought of adding a pump...only teasing! 😄
Yes, another video on this.
Did you ever think of having a boiler box stove in the main room to feed the radiators? Or is it rather redundant as you have this in the kitchen.
There is a massive stove in the main room that can heat the whole place just by brute force!
I thought would be the case, cheers for the answer. Another question, what does it feel like to have a life that many people are envious of.
Though it's hard work it seems like you have such a content and happy life.
Always considered flat plate collectors as a pre-heat system, topped up by back boiler and/or immersion heater. That was until I installed a tube system which is far far more efficient. Now I have no back boiler on the woodburner [getting more heat into the house] and very rarely have the immersion on. The system provides all the hot water I need for a couple of showers a day and all the washing up. As it runs at mains pressure It also feeds into the dishwasher and washing machine. In the summer I have to bleed off some heat on occasion. Tube systems rule IMO.
Hey Max are you going to add your vacuum water heating tubes to your system ?
The cooler the panel temperature, the less the loss of heat to the environment - and the more energy you will get into the hot water reservoir...well that's the theory...hope that was worth commenting on!
Another great video. Thanks. This has me thinking.
I am just about to do a modification to a 30sqm building to make it a live/work. It is not off-grid. It is a garden building 25m away from a house. The services will be trenched to it first.
I have ruled out putting gas to it, as the regs are awkward. So, I will put water, electricity and comms to it.
It will be airtight and have a small MVHR plant.
I was thinking of heating it with electric underfloor and a wood burner for MVHR, and am toying with putting a water system under the floor as well as the electric. I am assuming I will need to plan the systems for this carefully, and that I need a heat exchanger with input coils to connect with the wood burner and possibly coils for a wet solar system.
The main reasons I am doing this are to have a place to live in winter, which is cheaper to heat than the main house, and for when I am recovering from bouts of surgery, which I will have to endure at least another 5 times in the next 10-15 years.
The house is really awkward for mobility, and modifications would be very difficult. I don't really want to move; it's a nice house.
Looking at this statement, it all sounds a bit complicated. Realistically, maybe an airtight friendly free standing wood burner and the electric heating system will keep it simple and be adequate. It will be well insulated, so maybe I am over-egging it. If you have any suggestions, they'd be welcomed.
Thanks.
You can vent any woodburner from outside (which is a good idea anyway to avoid drafts). If I was building again I personally wouldn't bother with underfloor heating, it takes too long to warm up and even though the slab is insulated the heat dosn't seem to store very well. The other drawback is that underfloor heating only really works well with a stone/concrete floor and I prefer the proper floorboards in the rest of the house! If you're expecting to have mobility issues, maybe consider a multi-fuel stove instead of a pure woodburner? Just thinking of the number of times, you'll be needing to refuel it. My kitchen range is multi-fuel and being able to run it for 12+ hours on one load of smokeless fuel is a real bonus in the depths of winter. It sounds like you're on the right track, thinking ahead is a v good move. I know what is like recovering from surgery - I sincerely wish you a speedy recovery each time.
good vid
u have a few less hi -vis jackets than what i d LOL! & my dumb bells have more weights on
I'd say lag the cold return-side also, it will cut down on losses, making the return-water going into the panels hotter, and this will in turn slow down the thermo-syphon a bit, but you are talking about having to throttle the valve anyway, so all in all, I think this will allow you to accumulate a higher final temperature at the end of each day. The thermo-syphon will be able to self-regulate the flow of water better.
I think you have done a great job.. like to see the system work.
You say the flow rate is too high, so bends in the pipework can’t be an issue with yours? In fact if your thermo syphon is flowing too fast then lagging the return may be a good idea to slow it down. May even increase the output temperature and lowering heat loss too.. if it didn’t help it wouldn’t be a big job to take some back off anyway!
Legionella is the worry with warm water hence get it to 60 degrees every 24 hours,, but people scare easily about this.. it takes about a week for water to turn stale and the issue arise anyway.. think your managing it ok ..
👍👍👍
On the subject of efficient use of PV to Solar Thermal (the guy could be right) if you've got 20% efficient panels and you are then using that electrical output to heat water, cut out the middle man and just go direct to solar thermal and reduce losses. Yes everything can be lost as heat, but electrical efficiency in generation and subsequent use does compound even if the end state you want is just heating anyway. Probably not so good in most of the UK, but in my place in Greece Solar Heaters are absolutely amazing for domestic needs.
Great experiment, but you need to lag that return pipe. The circulation will still work fine and you will get a higher water temperature.
Maximus. split a shower thermostatic system into the pipework to control the transfer? Cheers
Super!
Love the system, hope you find time & space for the solar tubes you had - I don't see why you couldn't just have rows of them on the wall to the left of these with their own thermo-syphoning system (maybe just run them parallel?).
I feel the very minor improvements you could do to this system are either paint the exposed pipes from the panels black (to absorb even more solar heat) or insulate them (and really even on the return line). So long as a pipe is beyond the bottom of the system, it would be beneficial to paint black at the least.
Regarding the return line... If the solar panels give say a 30 degree temperature increase, then if it's entering the panel hotter it will exit hotter. Also, having the pipes at the bottom of the system exposed will mean the water in those pipes can get even colder and will be harder to lift into the solar panels where it'll be heated.
Distracted by chickens! :)
Hello Max, I just discovered your channel and really enjoy your videos and I’ve just watched your Solar Hot Water series, great design, cheers. My only thought is if the exterior plastic pipe riser from the solar panels is resistant to the UV exposure and if it needs to be protected. It’s now 27 January 2022 and it looks like 4-years after you built it and released the videos so if there is a UV problem you might have discovered it by now. Thanks. Michael
It's still going strong!
Fascinating, have you thought of geo thermal for heating?
ianmedium, boss of the swamp covered this question quite well 😉 see link 👍
ruclips.net/video/823QapBt6Z8/видео.html
Max please insulate every piece of pipework that is outside (and the return line inside as you say the thermosyphon is too strong anyway). You have seen a good improvement to temperatures by insulating your tank and I'm sure you'll see a similar improvement by insulating the rest of the pipework.
Anything uninsulated outside is just leaking heat that could otherwise end up in your tank.
That is my only criticism, great job and looks like the effort is paying dividends!!
Hi max, not sure if you're aware but three UK just ditched the 30gb tether limit on our plans 😍
Really enjoyed all your videos and explanations of how the system actually works. One question regarding you not lighting the range to heat water but how are you cooking?
At the time of the video, summer cooking was on propane but now, as I have more solar panels up, cooking is all electric!
Noticed the increased number of panels in another video. Is there a video with an update of your power supply/system?
I've been doing regular updates for patrons. I'm still in the process of upgrading it all, I may do an overall update video when (if) I ever get it finished.
That's very cool mate. Or, more accurately, hot! Are you ever going to try something with the posh evacuated tube hot water system you've got? It's probably not necessary given the results you've had.
Hmm 🧐 how happy are you with the heat exchanger in the tank could that be optimised for a better result it seems to me that everything revolves round the workings of that !
Just a thought that kept cropping up in my mind 👍👍💪
And again 😁👍👏👏👏
if you still have this system installed (with the range and the fire lit ) it might be worth putting a thermostatic switch (set at 95C) on the pipework somewhere so it turns on the underfloor heating pump to dump the heat into the concrete before the water starts to boil!!
nothing worse than falling asleep in front of the fire and being woken up by the pipework banging and clanging as the water turns to steam
I have worked on designing controllers etc for solar PV and one of the issues is efficiency is lost when the cells get too hot. Energy from PV is not great for heating however this water heating type of system is significantly better and possibly the best system currently available for heating from solar energy. This leads to a question: how could the two be combined? IE a silicon PV panel (as GaAs is way too expensive at the moment) with water taking the heat from the cells and being used to warm the floor. That way you could potentially get significantly more power out of a panel than either system on its own. Not sure exactly how you could get even heat exchange on the panels but I'm sure someone could figure it out.
Would a smaller diameter feed pipe from the Solar panel help so heated water won't be drained off and get to the tank faster to transfer the heat in the tank? I'm late but enjoying your post. Yhank you.
I live on a boat I'm putting a couple of these pannels under my bifocal solar pannels and I know there are German pannels using more of the sun power on a smaller foot print... I love your keep it simple approach to things can I pick your brains about your underfloor heating are you available for work?
I made a video in the off grid living series all about heating in which I talk about the underfloor heating. As for work, I'm snowed under with my own thanks!