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Forum Index : Solar : Deciding if I should build this solar heater
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| rogerdw Guru  Joined: 22/10/2019 Location: AustraliaPosts: 852 |
Nah, much to my wife's embarrassment I drive a 25 year old Holden. And much to my annoyance I sold my 55 year old Holden about 20 years ago ... though it was to my eldest daughter ... so it's still kinda in the family. I guess it does but I really have no clue about cars ... a bit about motorcycles, but generally only older ones. Yes, I'll say. Won't be long and I won't need to run it because it will get too hot ... but it's definitely saving us wood. Having said that it does take a few hours to get up to a decent temperature ... and a bit of cloud or rain and it drops off pretty well. Today was a classic in that it was supposed to be gloomy, 15 degrees and rain ... and the thing fired up at 7:40am. It ran for an hour and a half before things went black and the rain came. Then the sun came back out for a while so it ran again ... then more grey and rain. I don't recall ever seeing a day where the conditions changed like it did today. Something like 15 changes from beautiful sunshine to grey and rain and back again. Yeah, fair enough, though I was referring to the global warming climate scientists ... with probably a heap of them on the other side of the fence 50 years ago telling us we were all going to freeze to death. Yes, fair enough again. I certainly recognise the variables having grown up on a farm where you can get a heap of rain in one area ... and only a km or so away you might get none ... and have nice sunshine. I have an online local directory and installed a weather widget for this area for just that reason. Adelaide can be quite different to here only 80km away ... and the other thing I found was that most of the widgets get their data from google. While I was working out which widget to use, I could never work out why there could be as much as 5 degrees difference between some of the forecasts (for this town). Quite ridiculous figures sometimes. Anyway eventually I discovered that most got their data from google ... but the accurate ones got theirs from the BOM. I had to have a widget created to accept the BOM data because the other was so obviously out. Seeing this forecast so often during the day, I often notice they update their forecast on the run ... and it does look a bit like they're cheating sometimes because anyone could do the same ... guess at a number ... then when they see they're gunna be wrong ... just adjust it and hope no one will notice.  Cheers, Roger |
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| Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578 |
That is to be expected. Solar radiation is at it's best from about 10-2 if not a narrower margin in winter so anything reliant on that has to follow the same ramp up and fall off. The reason I overclock My PV is to get it making decent power early as possible, get it producing full power as long as Possible and have it still working late as possible. Bit of flatten the curve only I mean it and it works unlike the other previously used and failed presumption of the idea. The bigger system will give a marked improvement however than what you are seeing now by the same way. More heat earlier and right though. We get that many times a year here. Rain from a sprinkle to a downpour then the sun comes out and soon as the paths get dry, It repeats... all day long. Friend asked me once, " Did it rain there today?" I said yes, at least 8 times. He said was sunny here. I said yes, was here too, at least 8 times! I think these sort of predictions are just like these Miracles that have just been around the corner for 50 years that "COULD" change the world that never appear. They are really to elicit funding or investment or some other money making scheme. If these Scientists can get funding / a solid job for 10 years, all Good. Time it's discovered their predictions were off, there is something else they have invented to worry about and investigate. I'll give them this, they said it was going to be cold today and It was. Colder and a bigger change on yesterday than expected. I don't know how the rainfall has measured up to what they said, too damn cold and windy for me to go out and check. Had the fan heater and the Diesel on all day and the Kitchen has barely cracked 20. I have noticed this too. The BOM used to issue the forecasts at 4:20 AM and PM only. Over the last year or so they seem to update and amend them anytime. I saw one in January at around 10Am and another at 11:40. I remember those days were predicted to be " Batten the hatches" Days and I was out around 10 Am looking at my inverters pleased with how much solar I was making. I also just noticed when I put in my area into the BOM site, it gives the forecast for " Sydney area" and the local predicted temps. Same with all the places within Sydney they are specific for. We are 80 KM from the CBD / Coast and the weather is known to be very different here and much closer in at Liverpool. I did notice though, the location of where the radar is for Wollongong is half way between them and us so much closer than Sydney. Their forecasts for Wollongong don't agree with what we see either. Looked at that Initially but they were just completely different which makes sense. No wonder it s out for this area but it's also just as inaccurate for where I used to live only 20 Km out. Maybe once you leave the Lawn at Observatory hill where the BOM is, it's all bets are off? I have some radar portal on my Tablet. I have found it useful particularly when storms are around to refer to that. Gives an indication of the rain and wind intensity and you can see which way it's coming or going. The one on Flight Radar is also handy if you are subscribed to that. |
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| rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 852 |
Good analogy ... like over clocking your inverters. Definitely rare for us ... maybe once in a while but not a heap of times in one day. If there's a big storm forecast I'll do the same to see what's coming. Always helpful to know if it's likely to be a big one ... though that's more than rare over here. I watched your new youtube video today ... got a notification around lunch time. Good viewing and love the commentary. Just the right amount of sarcasm ... great job. And the comments are just as much fun to read too.Cheers, Roger |
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| Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578 |
I was thinking of exactly that. I can load on the panels to get the max output early and late as I can without going ballistic in the middle of the day when I don't need it. I was thinking how to throttle your system the same way. I spose all you can do is vary the fan speed or Dump the heat if you can't have the tubes too hot. That would be a shame so I come back to the old Broken Record position of storage. Might be worth holding off on that for a season. Might not be worth it for the time you do have excess heat. That said, the weather forecast was wrong again here. Supposed to be 26 down to 13. It was 8 around lunchtime yesterday, 4 before I went to bed last night. That's a BIG differential in a day! Not dumping on the weather mob, for once, the difference in temp to what they said irrelevant, it was just the change and how cold it actually gotfrom one day to the next! With the wind felt positively Icy even inside. Not surprising, the wind was blowing the rain right against the house under the 4M wide Verandah. Don't remember seeing that before! Probably had a significant chilling effect. I'll bet all the Woo hoo Flu cases will spike just through people getting colds through that and being used to push the agenda. Not too warm today either. The wind was pretty disturbing here last night. We usually cop it in August, it's the month I fear but this year it's been nothing... Till now. Wind might be late this this year, better if that's all we get. I curse because we are on a double slope on the side of a rise and get a lot of water run off when it rains hard but far as the wind goes, I'm glad we aren't up on the top where the wind has a direct Path. We have the biggest tree in the district in the front yard and the noise that makes is incredible. Lucky the prevailing wind always blows it away from the house or to the sides or I wouldn't be able to have it there as it would scare me too much. Haven't checked the rain gauges yet. Hard to estimate what we got as it was a bit all over the place with the rain intensity and the wind complicated things as well. I don't think it was near what they forecast, maybe 25mm, they predicted 70. Guarantee it wasn't that much or close to it. Good to know the notifications are working in part at least. I noticed a lot of people hadn't seen the last one and I have found a LOT of the people I am subbed to I don't get the notifications of late or get them a week later. I wasn't really happy with that vid. Thought it was a bit boring and not all that entertaining. Might take a bit to get back in the saddle as it were. I was pushing a bit as I wanted to get something out but it didn't turn out the way I would have liked. I have got some good comments about modifications to that burner I'd like to try as well as some other things I didn't cover. After I finished editing the vid which took forever on my old machine, I realised I forgot the cooking bit so I can go back and do that again and I want to lengthen the flue Pipe as well. I am very much Missing doing my dumpster diving with this lockup BS for bits of scrap and offcuts I can use. So much junk but none of it what I need or can utilise. I Wanted to do another Vid about a week after the first and keep them regular but weather and lack of motivation conspired against me. If I can get ahead a bit which I should have done in the first place, I can upload and program the vids to drop regularly. I did half shoot a Furnace Vid and a Solar welding one I didn't get to finish so when the weather gets better, again, I'll complete them. I wore a mask but still managed to give myself a hell of a welding flash with the solar one. As it was I had an appointment with the eye specialist a couple of days later and he had a look and said all good. I have flashed myself before but that one was not good. Couldn't keep my eyes open that night and couldn't keep them closed either. Actually my eyesight had improved and the retinopathy I had is all cleared up so that's good. Still very frustrating age has made reading fine print so damn difficult and I swear they print stuff in fractions of a point size now. Got some medication the other day and I could barely read the bottle with an 8X magnifier. Yeah, print instructions people cant read on a medication bottle, that makes sense! I was thinking I might just do a vid blasting some things with Mega heat. People seem to love glowing Bricks and bits of metal. Thought I could heat up some old disk Rotors I have and maybe drop them in water and there is a 20Kg Tractor weight up the back I could blast as well and get that glowing. Once I get the Dirt furnace done I have some brass to liquefy. Good day for a Burner Vid today being so cool outside. Might warm me up a bit. Days like this are unfortunately where solar fails. Because it's overcast you want the energy be it heat or electrical and it's when the solar is at it's most useless. For the days like we had, it does redeem itself though. Even though outside was quite warm and I had all the windows and doors open, the house warmed very little for whatever reason. I think I'll set up a fan and put it in a window with a surround on a thermostat. When it gets over 20OC the thing will run to force some warmth in the place. Maybe pushing the air in with the 10" 400W fan I have will give enough volume and air change rate to make a difference. Wouldn't think it would be that hard but I guess the differential is low and the thermal capacity of the interior of the place is higher than what I presume. |
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| rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 852 |
I think that varying the fan speed can do most of the control. If we don't need the heat, I'm sure I can just leave the tubes to cop the sun ... they are glass and can cope with hight temp ... though if I could divert the output, I could just let the fan idle to move a bit of air through so it doesn't get too hot. Of course, then I'd be looking for something to warm up. Maybe the pool water via a heat exchanger. Still needs some thought there. We rarely have any trouble with wind fortunately ... just the occasional windy day that makes outside work uncomfortable. Not surprised. it would worry me too. Yes, good to hear they're working in your favour ... if it was facebook they probably would have hidden all your stuff coz you're politically incorrect or something. I thought it was all ok ... quite a bit of info with the right amount of humour and silliness. Yes, there're a really supportive crowd and come out with all sorts of suggestions. Definitely a few worth following up. That's a bit worrying, hope there's no long term drama. My eyes are ok, though I definitely need glasses for fine work and reading ... plus surface mount gear certainly tests them out. Haha, sounds normal. Give em what they want. Was pretty ordinary here too, though the thing is starting earlier and earlier. Started at 7.36 this morning and I was still in bed. A month ago the tubes were still one third in the shade at that time .... but now only a few inches of shade across the bottom. Cheers, Roger |
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| Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578 |
I was wondering more about any plastic fittings or ducting. They should be able to handle any hot air but as long as there isn't anything in contact with the tubes themselves. Then again, most plastics take a LOT higher temp than people realise. Years ago the veg oilers had a go at me for using plastic Fittings on the coolant system of Vehicles I converted for veg oil use. thought they were all going to melt etc. Did a vid Boiling the bejesus out of them on the stove and they didn't even soften. then I changed the water for oil and had them up to 200C and they still weren't softening to any degree. :pt of different types of plastic so depends on what you use and what the temp is. I'd imagine that the real hot parts are inside the tube with these anyway. Is it close enough to the house to be practical? The method in my grandiose ideas is always the easy part compared to the practicality and aesthetics of implementing it. It cleared here for a bit late yesterday. I went and got another couple of meters of flue pipe and put it on the burner. That sure made a difference. the thing sounded like it was being fed compressed air. I was able to block off a lot of the secondary air holes with a bit of aluminium foil layered over and it still ran quite clean and was glowing red hot. Lesson: do the secondary holes with the amount of flue you want to use. The ally Foil melted and the thing backed down a bit because the secondary holes are excessive with the longer flue but it does run very clean. I would guess by oil consumption it was up to about 50KW but the efficiency is the question. That said, I think the longer flue was able to pull a lot more heat out the gas even without and baffles. I was thinking a number of old bolts welded into the flue may be enough to break up the gas flow sufficiently to get good efficiency out of it. Not having much luck finding a heater like Tony advised but then again, not much being advertised here because there is no point when people can't go get it. Comes down to being reliant on nature and the weather. No matter what we do with tubes or panels, we can only make the best of what's available at the time. Friend asked me the other night why the solar fall off was so great in winter? I said it's winter because there is so much less sun intensity and that's why it's cold. I'm obviously a big fan of solar but it certainly has its limitations which is why for me going the veg oil route for heating is preferable. I'd still like to look at using the panels from a verandah for the air heating but the way things are going that's going to be another longer term improvement than what I anticipated. Checked the rain gauge yesterday. 34mm so I was a bit out but Closer than the prediction. Very sunny here this morning but they are saying cloudy. The overnight temps are still predicted to be around 3o. Always colder here so still might see a frost. So many more hours where one is fighting against temp loss than is available for temp stability let alone gain. |
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| rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 852 |
The big one will only be metal and glass along with some foam insulation inside the ducting cover, so that will all get pretty hot out on the roof ... it's only if I turn on a fan to push air through it ... then it would need to exhaust outside somewhere. If I'm using the heat from the tubes, the temp stays down between 25-45 degrees ... but if I turned off the fan on a hot day and let the heat build up ... then it is likely to pump 100-150 degree heat through the ducting .. and then I might be in trouble Haha ... same here. The pool is diagonally across the house from where the heater will be ... so a fair distance. It's amazing to hear how small changes can make so much difference Has to be worth a try. Anything I suppose to stir up the air going past the hot surfaces. Unless it's a lot different over there ... it must be the fact that people know that buyers can't get out. There are constantly heaters for sale over here ... a lot of the flue-less ones ... but also a lot of the built-in ones which I understand was what Tony was suggesting. Yeah, you can't beat heat on demand compared to maybe some heat if you're lucky. I did come across another guy in the US who was pushing the same idea ... of gaining the heat from under solar panels ... in fact he designed and was selling swimming pool heater systems that fitted under solar panels. I'll see if I can find the links for you. I'm a bit dirty on him because I rang his company a couple of times and eventually they said send an email, which I did ... but still no reply! Here's one link Cheers, Roger |
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| Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578 |
At the high end, I could see how anything plastic could get a little Sticky... Pun intended. Would the foam be in the air path? I picked up some 8" Ducting from my friend last week. It's a foil material with the insulation which appears to be some sort of plastic based felt type material and another layer of metallic foil. I'd Guarantee it's not designed for 150o but whether it would handle it or not is another thing. I would suggest if you don't have other uses to make sure the system can be shut down so it inadvertently can't be switched on if there is anything that will not survive the high heat in summer. You could put the HE close to the house and run pipes if you have lawn to circulate the water. My gut intuition is that there is probably concrete between the pool or the filter at least and the house. That makes things difficult. Still, if you can get some good coverage on the roof and sides of those sheds, electric heating will be easy. I have to say, it was quite the eye opener to me as well. More than enough heat for the house, if I can capture it efficiently. That will be the trick and I think forced air is going to make that much easier and open more options. Was also thinking that an air HE will be so much easier. I need a fan and ducting. For water need pipes, radiator, pump, header tank.... That said, I am also mindful of what Tony mentioned, metallic smell of hot steel. THAT could be an issue although I haven't noticed it on the well burnt and rusted pipe I have used on this test setup. . [QUOTE Has to be worth a try. Anything I suppose to stir up the air going past the hot surfaces. Another thing I was thinking was something like a set of car extractors where there is many pipes of smaller diameter which would likely give up the heat better then exhausting it out to one. I think that would be good for an air HE where I could use something like a 44 to enclose them and blow the air though. Gets big and bulky then. Maybe I should just get the water heater with the forced air burner up and running, see what I can learn from that and go from there. The draft burner is alluring in it's simplicity but that is also offset by added complexity in HE design and cleaning for a start. Yes, I think that's exactly it. I haven't been advertising panels for the same reason. Although maybe I should give it a try? Might work for me if the supply is limited atm for that reason. Whoever wrote that piece waffles on more than I do! Geez they stretched that out! They were quoting 18W panels which prompted me to look at the date, 2010. Things have come a long way. They also seemed to quote a pretty low output rate for power and heat combined but looking at the efficiency back then, puts it a bit more in perspective. I can only assume they were quoting winter thermal output as that was low but winter realistic. I want to see if my mate has any 8" T's and flange fittings so I can link multiple panels together. I had the solar heater going the other day when it was warm but the bilge blower just isn't enough. The top 6" of the panel where the air comes in is cool and the rest sits at the same temp. The air coming out is warm, just not enough to be effective or utilise all the heat from one panel. Started very sunny here this morning but clouded over in the afternoon. I made about 56Kwh which isn't bad.... Till you put it in perspective. The couple of cold days I ran the fan heater on high, 2 Kw for 36hours or so non stop. Wife had the heater on in the lounge room where she is working and then I went in the bedroom with my tablet and had the heater on in there for a few hours although only on low. If we didn't average 80 KWh Both days, I'd be surprised. I did fire the diesel but it's not right. Output temp is low and I suspect it's sooted up. Only been running it on dodgy Diesel but I also suspect maybe a gasket or something has gone because I can smell fumes in the air coming into the house. I'll get a gasket and pull it down and see what's happening with it. |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
I have accumulated a few of these over the years, and mid winter is not a good time to be looking. Nobody starts doing extensive home renovations when its cold and wet, late summer is probably the best time to pick up a bargain. When working on government solar heating projects, it seems that a sustained temperature of 80C will be enough to cause long lengths of PVC to soften enough to sag significantly between the mounting points. A short burst of higher temperature might be o/k though. I suppose you can experiment a bit and turn the system off if the pipework starts to feel both very hot and soft. Cannot comment on your combustion experiments, its out of my range of experience. I did once build a natural gas burner and a small furnace for melting aluminium though, but have never done anything with oil. Cheers, Tony. |
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| Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578 |
Cannot comment on your combustion experiments, its out of my range of experience. I did once build a natural gas burner and a small furnace for melting aluminium though, but have never done anything with oil. Must be about the only thing I know more about than you. Pity it's not something far more worth knowing. :0(. I'm quite knowledgeable in a lot of useless and worthless information. The basics are very straight forward but a LOT of people don't get it. They think oil burning is about atomisation. It's NOT. It's about heat to phase change the Liquid to a vapor/ Gas. So many seem to struggle with that and think it's all about having a fine mist spray. I realise a lot of commercial burners do that but it's the reason WHY they do it that counts..... To make the oil phase change to a gas more readily. After that it's really like any other combustion, getting the air/ fuel mix correct... which is the other reason they use spray in commercial burners, mixture and emissions numbers. One day I'll get round to making a burner that uses a power steering pump to atomise the oil but will still be more complication and expense than just running a blower so bit of a mute point. It's easy with the forced air burners to make them run clean because I build them to work on excess air so they are always as clean as possible. Exactly like a Diesel engine. Until you overload them, they run clean with more air than they require. The drafts pose different challenges however. I have spent the great majority of my wasted time on Forced air. Had I spent as much on the drafts, I'm sure I'd be better at them. That said, the reason I haven't taken more interest is because I believe the forced air type ( rather than the compressed air type which are a total waste in my book) is FAR more useful in a much greater range of applications. That and I worked out long ago big, ferocious flames get far more views on YT than smaller more practical devices. My main difficulty is in the low outputs with forced air but again, practice is working that out and when I go back to old vids, I actually see I have done it years ago and forgotten. I think at this point my greatest hurdle is what seems to be mental decline and lack of motivation for anything. |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
Dave, can you provide a link to your videos ? Cheers, Tony. |
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| Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578 |
Emailed you Tony. |
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| rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 852 |
The foam will be in the central duct where the hot air out of the tubes is collected before it is channeled off through the tiles and down into the house. Actually I need to source the foam soon ... need some 50mm thick sheets. I need to do some research, unless anyone else knows a suitable product and source. Yes, I might need to 'summerise' it ... get up on the roof and blank off the outlet so the hot air can't leach down into the house ... or literally cover the tubes so the heat isn't collected in the first place. You are correct. Concrete, fence, lawn, raised garden bed with large bushes/trees ... then more concrete. The solar heater for the pool works pretty well now ... it just needs to run enough hours to get the warmth up. Having an excess of power during the sunny part of the day when it's worthwhile running the heater is one of the few times when excess power can be used to our advantage ... so that is probably the best way to run it. I'm not sure why I'm so nervous about water based systems ... but air ones have to be less risky. I do recall my brother coming home to his new home with it's lovely sunken lounge having filled up like a swimming pool from a burst pipe ... ... and this place before we bought it, despite only being a few years old, had sprung a leak under a bedroom floor and flooded the whole house. They scored new floor coverings for the whole house when they fixed it ... and that was when they put in the the half acre of fancy ceramic tiles with the under floor heating cabling below ... that has never been connected up as you may recall. I guess that could be a possibility, though you would hope that it would subside once the system had been running regularly for a while. Yeah a bit like the boiler in a steam engine. Haha, yeah ... lots of late night visits from people with trailers. And you could probably up your prices a little too ... supply and demand. Sorry about that. I couldn't find the link I was looking for ... was a video showing the way it worked with a system set up on a trailer that he must have carted around to demonstrate. He clearly stopped marketing the system because there is no sign of it on his website now ... but I'm sure I found it on an old version of his website on the "waybackmachine ... archive.org" He had designed the pool heater rubber tubing system to fit beneath the solar panels pretty much the way you talked about collecting hot air under them. It must have worked well enough for him to take it to market ... though obviously not well enough, or it would still be being sold!!! His hot water panels appear to be pretty successful ... very lightweight and easy to install ... check them out at solarroofs.com. You're right ... 56Kwh does sound good ... but obviously doesn't cut it with your heaters running the way they are. I heard the fan fire up at about 7.31 this morning ... so I got up to hook up the data loggers. It was 3 degrees outside and 13.7 in the lounge. Don't think I've seen it that low in the lounge. Anyway, because it turns on when the tube temp gets to 12 degrees above the inside temp ... it turned on at 25.7 degrees. Then of course it dropped, so was pumping 19.5 into the lounge. It was nice and sunny outside ... just cold ... so I decided to turn it off for a while to let the tubes build up a bit first. Turned them off at 8:04 ... and by 8:27 when heading off for school dropoff ... the tubes were up at nearly 70 degrees ... so turned it back on. According to the logger ... it took 13 minutes before it dropped down to 30 degrees ... another 10 minutes to get to 27.5 ... then it headed north for the rest of the day ... perfect day. The inside temp went from 13.8 to 22.2. Not super high ... but made some inroads into the cold. Cheers, Roger |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
It should be possible to just leave it switched on 24 hrs, and just let the differential controller do its own thing. No need to let the tube temperature build up initially, that is just wasted heat. If its 13.7 inside and its pumping 19.5, that is still heat gain, which will then rapidly increase as the sun rises. It will likely cycle a few times by itself initially if it needs to, but just let it take care of itself. If it ever does start pumping continuous cold air when its freezing outside, adjust the controller settings up a bit. Cheers, Tony. |
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| Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578 |
I don't know if the tubes or the coatings degrade over time but if so, may as well preserve them when you don't need them. Summer sun will be the most harsh of course. Yep, Get on to those panels so you can supplement it! There was a guy on another forum I saw a while back made his own solar HW heater by Putting a load of small heating elements in a pipe and used an arduino to switch them on depending on the power the panels were making. Basically switched them in to keep the panels on Power point. As I recall you want to keep everything off grid ( just to make it more difficult! :0) ) but you could sink some screw in water heater elements into a pipe and run that in the flow from the pump. They are pretty cheap and you could run multiple in series as the heat gain per element in running water will be a couple of degrees if that. Lot will depend on how you set things up. Once you have the warpverter as long as you have enough panels you could use that just to virtually power an element direct. Yes, I was thinking the same with a spa but I'm having second thoughts if I'd even use it now. Must have been sitting there close to 12 Months now and I have no inclination to get it in and use it. Said to the wife the other day are we really going to use it If I do put it in? Worked enough in pools to know they can be nice and warm in winter but the little round ones want to redeed into your throat for warmth that's lacking in the winter when you get out. Then again, if I go way back to original ideas, it would be a good reserve heat source in winter. Run a veg burner in a spa heater with the gas burner removed and I could throw 100 Kw at the thing for a nice quick heat up once a day and that would be it. Thing just seems a lot of work to put in and muck around with though. Yeah. In my mind all the water works would be outside and the hot air would be sucked through a radiator and into the house. The old thing of it could flood all day and I wouldn't care because it would be outside. Fear of Mine too. Mate had a couple of those flexible pipes like under sinks go 14 Months apart. Being in the country getting the first lot of damaged which was substantial was bad enough, 2nd time round was a war with the insurance company for nearly a year as they were claiming deliberate. Apparently the things are supposed to be changed every 10 years. Cause it's about 100M to the water meter at the holiday house, I put a WOG valve where the water comes in beside the house. When I leave I just flick that valve off and the house water and any potential leaks are eliminated. Yes, I'm thinking burn the hell out of it initially and run it a while going outside and should be fine. It will be black pipe so just the coating to burn off but I could wire brush it beforehand as well. I missed the PERFECT HE for the job, proper marine HE in stainless that was capable of 42 KW. Was up the coast and with lockups I wouldn't have got far. Only wanted $50 for it and someone else whom knew they are over $1000 to buy new obviously snapped it up. No, I appreciate the link. There were a few things in that that confirmed what I suspected and it was interesting to see their approach. I have seen commercial water cooled panels, don't recall from whom now but I remember they were plenty pricey to the point of not really being worthwhile. Discussed them on another forum at the time and the consensus was the same. Pretty sure these ran the water direct on the back of the panels which gave rise to concern about sealing the cables and seepage to the cells. Tired of staring at bare roof! Need to get more up. I was thinking the other day I won't need them so much now. Then I was thinking how much they keep direct sun off the roof in summer so they are probably helpful for that reason alone. My wife bought me this terrific new toy yesterday. It's a clinometer and a Compass. Perfect for solar stuffing around and doing setups. You can do angles and use it to measure height of trees and all sorts of things. You actually site your target like a Direction or the sun height or whatever and then read off the number in the eyepiece. Can do roof angles standing on the ground, setup panel angles and all sorts of things. Been playing with it today and love it already. Sunnto Tandem I still have my " Silva" compass that I was given when I made troop leader in the scouts. Love that too not that I have much occasion to use it but I sure know HOW to use it! https://www.forestrytools.com.au/index.php?id=908 Going to enjoy this one. That's warmer than I have had the interior of this place in at least 3 Months. I think that';s doing very well! I had it up to 21 On Monday I think it was we got the warm snap and thought that was good but 22 is better! Be 32 This time next year with the big heater! |
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| rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 852 |
I'll respond to your earlier posts later tonight. Just came in for a coffee after trying to weld these aluminium tubes into the 6mm angle.  I know, I know ... don't give up your day job!!! Here's the first one ... half done ... 59 to go ...  First two were with the oxy using standard aluminium filler wire and flux etc  Gave up on the oxy and tried the brazing rods again ... using a propane torch.  Think I'll stick with this method  Once they're all done, I'll tip it upside down and sweat in the other side. The brush marks on the ally are from when I cleaned it before brazing ... and I've done nothing to it since ... that's the finished look.  I had one run through and down about 2 inches. I thought I'd grab it with an old pair of side cutters and twist it off ... like solder when it drips. The amazing part is it is actually bonded properly to the tube and I couldn't twist it off or cut it off ... so this stuff does actually work. Huge relief to see that I can actually complete this part of the job as it's been a roadblock for a month.  Cheers, Roger |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
Yup. Welding aluminium with oxy acetylene is not really possible. It just oxidizes. Brazing rods are expensive but they do work very well on clean de greased aluminum. Its a slow process though, the heat really spreads, especially with thicker material. Cheers, Tony. |
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| Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578 |
Reading and looking at your first pics I thought " Yep, exactly how I would expect them to look, Ally is NOT easy." Looking at the last ones, that was NOT what I expected. They look brilliant! I'd be damn pleased with them I did them. Actually, no, I'd think I was dreaming and someone else did them for me. Don't get too pedantic with the double welding. These things have virtually no structural load and only really need to be held in place and sealed up against low pressure air.... that won't matter a damn if there was the odd tiny leak that may be there. Thats a VERY good job there Roger, very Impressive. Could you link the exact rods you are using? Would be an asset to be able to weld ally like that. You didn't try TIG'ing them did you? Long time since I tried. Your first attempts looked a lot better than mine. Bought the machine to do it in the new welder, might be worth another go... if I can find a need for it. I remember seeing tube expanders years ago. I believe they are what they use for doing Boiler cores. The bit is inserted into the tube on the end of a drill and flares and Knurls the tube into the hole in the plate and seals it. As I recall they weren't cheap but maybe they have something Chineeseium now that would be lower cost and make the job easier still? Being ally, there may also be something in the conventional type for plumbing that would do? Mate has one that looks like a rivet gun. Put it in the end of the tube, squeeze the handles and the (copper) tube is expanded out to size. This is the boiler type I was thinking of. There is also this type that may do. These Simple/ Cheap types could probably be DIY'ed or made to the size you want by a local machine shop. |
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Murphy's friend Guru Joined: 04/10/2019 Location: AustraliaPosts: 648 |
Thanks Roger, for those very educational welding pictures  . They convinced me to never even try to weld aluminium, your brazing job seems to look very good BTW. Its still a lot of messing about with a hot flame though.But I'm with Davo's suggestion about flaring the tube ends and jam them in place. If you have a lathe it should not be too hard to machine a suitable cone and threaded rod for the job. Considering how many tubes you have to do, it could be a very worth while task. |
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Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1022 |
That should do the job well enough Roger, That is a lot of Ali to heat up to welding temp, in any case.  This is a fuel tank for a boat, built back in 2002 some time, its not that tidy but it was under the floor where know one could see it, the preference was to have absolutely no leaks. You can see the the bead from each dip of the rod wile running the Tig and every so often it has run over a tack made by the Mig to hold it together. It was wire brushed before welding, then finally acid washed.  The braze welds you have are as I would expect them to be, quite smooth. This would be one of the more difficult areas (thin pipe onto thick angle) for a Tig weld...On a good day. Would also find it difficult to get the Tig around the back of the pipe between the angle. The braze rods you have are the way to go. Looks like a good job, keep at it.  Cheers Aaron Off The Grid |
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