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Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1577
Posted: 11:56pm 13 Jun 2021
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I think that's a pretty accurate Analogy. The panels will also have significant mass so should be capable of storing a bit of heat as well.
Once the sun goes off my panel, the fan continues to run quite well only it's then pumping in air that is now BELOW that room temp. By 4PM here it's freaking Cold. It's also pitch black by 5:30 Pm. Never really noticed things like that as much till we came out here and I started playing with solar. In Summer it can be 7:30 and I'm still making many Kw of power and the inverters don't drop out till after 8 Pm.
I think winter solstice is near. Thank god. Yes, Next Monday in fact. This week will be the shortest solar generation then it starts getting better. I'm sure happy for that. Did make 46Kwh yesterday though which was great. Be lucky to do 1/4 of that today and if the forecast holds up, the rest of the week as well.
That's Great! We had out run of beautiful Days a Bit early I think. Now when we could really use the sun it's overcast and Murky and forecast to be for the next week as well.
Another 3 Months and I'll be bitching about the heat here and looking for Cooling Ideas again. I think this Verandah will make a big Difference. We will then only have the short northern wall exposed and that's 3/4 Covered with the hedge I have let grow up longer for the shade so it's Improving. Might see about some small awnings over the doors where the sun belts in. That would probably help a lot too.
Maybe I should put a compressor and AC system on this cogen setup I'm building. Had that Idea for a LONG time now but I just keep running out of Round Tuits I need for this and so many other hair brained ideas.
Might be easier to work something out and useful for Both of us with out solar heating to put that to work for absorption cooling. Still trying to get my head round that completely.
The Board will certainly make things more practical and I'll go out again shortly for the Customary weekend trip to bunnys ( to get the things we went there for yesterday but forgot to get although still as usual managed to spend over $100 on impulse buys) and have a look where I saw the Boards yesterday which was only a few doors down. Also cruise past the scrap yard and see what people have dumped on the foot path and see what I can do as a community minded Citizen to help clean up by bringing some home.
rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 792
Posted: 12:18pm 14 Jun 2021
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I didn't realise it was that close but I'm pleased to hear it will soon be upward again.
Haha, yep ... same here I imagine.
Sounds familiar. Our Bunnings is only a couple k's away but I aways come home and then realise there was something major I forgot to look for.
I haven't got into that which is probably just as well. I still seem to fill the place up with heaps of rubbish anyway and have no idea where it all comes from.
One thing about my weekend cleanup is that I can now get at some of the stuff blocking the works and will now take some photos and stick it on marketplace.
I think my 'hanging on to stuff' is a legacy of growing up on a farm where you didn't throw anything away ... something I have to change. My wife grew up in a military family where they often moved every three months, so never accumulated too much crap coz it was just too hard to pack and shift it all the time. There has to be a happy medium somewhere.Cheers, Roger
Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1577
Posted: 06:51am 15 Jun 2021
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Made a more durable temporary setup with the panel heater today. Attached a sheet of the scrap ply I picked up on the weekend.
Ply was about 200mm longer than the panel so rather than cut it off, I used that to get the bottom of the panel up out the weeds. I haven't got to making the legs yet, other things to do and I was itching to fit this up.
Back of the panel with the voltage converter mounted. I have left the wires long in case I need some extra length when I attach the second panel. I think that may be better with a bigger blower so I'll look into what might be most suitable.
I set this up in reverse. The blower is pulling the air from the bottom of the panel and the air is entering from the top in about a 10-12mm gap I left. I secured the panel with some metal screws though the ply into the frame of the ply.
Eyeballed this downpipe spigot at bunnys yesterday and Miracle of Miracles, it's a perfect fit for the blower inlet. That's my good luck used up for the next 6 months! I use it as a flange to mount the blower and it's a press fit although I will probably tape it or put a self tapper in it to secure it if we get any sun and the panel produces some actual heat. I just cut a hole in the ply before I attached it to the panel and screwed the spigot over the top.
As this is a standard down pipe fitting, I should he able to use them to couple multiple panels up together and combine the air output. I think to go to the window I ill need some proper AC soft ducting which is double layered and insulated in between so there is not too much heat loss.
The blower pushes on neat as can be. Having the blower on the low end of the panel also means the duct is laying on the ground and the weight of it is not pulling on the blower or the panel. I have always liked to have air ( and water) flow against the natural convection. I read something years ago as to the benefits of this I can't even remember now but I do recall it made sense and that's the way I like to do it. Why I didn't before I don't know but could have just turned it upside down but anyway.
Top of the panel where the air inlet is. Why bother drilling holes when you can just have the ply sitting back off the edge a bit? I think I gaot the gat pretty rights. Using a bit of grass I could see the air is moving quite quickly and evenly across the full width of the panel and the air output at the end of the duct is the same if it's attached to the panel or not.
The ply was a bit warped despite my efforts to screw it from one end out while putting pressure on it to make it flat as possible but the good old duct tape came in handy for doing almost what it is actually made for in sealing something for ducting air.
With the next one I'll put something in to generate some air tumbling to see how much effect that has. It would be good to have some sort of adhesive that transferred some heat from the panel backing as well.
Weather is still predicted to be overcast for the next week here so Might be a while before I get to see how this setup goes and compare the output temps.
Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406
Posted: 06:59am 15 Jun 2021
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That is going to be really interesting !!Cheers, Tony.
Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1577
Posted: 07:53am 15 Jun 2021
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We always come home with a bunch of stuff we didn't go there for! Spent over $100 yesterday on some lemon trees and pots for the back Verandah. They do look good though and are nice touch. Made sure to get the docket emailed so if they Die we can go back and get replacements. Lot of people ( including us until recently) don't know that if you get a plant from Bunnys and it keels over in 12 months they will replace it under " Warranty". That is one hell of a dangerous thing with my Mrs!
I have got over the forgetting so much now because I write notes on my tablet and take that with me so I have a shopping list. Have a trade card but seems everything I get I'm lucky to get $5 off on the whole lot. The thing that really screws me over and drives me insane is their pathetic stock control. It does not matter what I want, how common or left of field, whenever I go there, there will be something ( and an amazing amount of times EVERYTHING) I want is not in stock. Not that they don't carry it, they just don't have it when I want it.
Got to admit, it's starting to do me favours. They are NOT the cheapest despite their advertising hype and they have forced me to find other, better ( especially in the service department) cheaper, and more interesting places. It's going to cost them more than one lost sale that's for sure. These places are a little further away but well worth the couple of Km extra travel.
I have a mental illness with collecting stuff and that is not a joke or exaggeration. I cannot help myself but I AM getting much better. I will say it's not straight out rubbish like Old magazines and Milk bottle caps like a neighbour filled her house with but rather just metal, wood and machinery. We have a council cleaup tomorrow and I went round the yard with the mrs yesterday and today and the main stuff we put out was household things. Yes, I did make a small pile of stuff to go to the scrappy but even the Mrs was happy with that. It's easy to get rid of, costs nothing and no problem.
For me the hard things are those that are not metal or timber. Timber I can burn. When we left the old place I must have burnt 500Kg plus of old timber. Beams that had rotted away, more chipboard and shelving than you could imagine and offcuts I don't know where I got. Put them in a 44 with a blower attached and had a firestorm raging while I did other things. Time I got rid of it all, the back yard and the neighbours looked like a snow storm had gone through with all the ash that had been blown out.
Fortunately the majority by far of my collections are Timber or metal. I do need to get into the shed badly and get rid of a lot of stuff we brought here and shouldn't have. Put that Off because I am lazy, hold on to too much and a lot of it is going to result in tears and put me in a bad place. Has to be done though. Just waiting for a run of good weather as I will have to leave some out side over night as I remove, sort, throw away and re organise. Got a lot of shelving and benches to put in. Tossing up whether to panel the walls as well to make it nice and me less inclined to make a mess.
One thing I have overcome is people giving/ leaving me stuff. Meaning well and me having a weakness for things I collected waaay too much and then thought WTF did I pick that up for... then remembering I didn't.
That's always good to do. Most of my stuff has been unsaleable junk but I never cease to be amazed at what people will try to sell and put ads up for things they want $2 for. I'm far too lazy to be bothered putting an ad up for that. I have taken pics of things I didn't want to throw out and then tossed them. I am overly sentimental and this was suggested to me as a way of having my memories without the clutter. Trouble is I tend to look at the pics later and regret tossing them even though there is absolutely no justifiable use for them.
I was just very brave. Mrs wanted to throw out a lounge we must have had over 25 years. Yeah, it looked that old and was well worn out. I have looked at getting it recovered but the prices they want are totally unjustifiable. So many memories with it and I still have great regrets over getting rid of it. I put on my big boy pants and didn't even start on the coffee the mrs made before saying you have to get rid of this or her to come help. I opened the doors, dragged it out, ( barely) got the tractor and lifted it up and took it out and put it beside the pile..... And noticed some other vulture has dumped a load of crap on the Pile mrs thinks they may not take. If they don't, the council will hear about it and come and get it. Bad enough having to deal with my own crap, not dealing with someone elses. Didn't take pics of the lounge, best I forget it and there are plenty of pics with it in there. Christ I'm a wimp!
I think my proclivity is a function of being raised by my grandparents where there was barely a day went by when you weren't told about how hard things were to get during the war and what they had then even years later, was so much better quality and when it did break, was repaired. I remember a place in town that repaired Radios, TV's washing machines and Fridges. The place was always flat out despite having a reputation of being a rip off as we say now but no one ever thought about throwing anything out till the repair mob said they -Couldn't- fix it. Many people in our street whom were also of my grandparents generation still had B/W TV's 10+ years after colour sets came in because the old set was still going and they were waiting for them to stop working before they would replace them. You didn't throw anything out JUST to upgrade it! What a waste of money that would be!
My grand parents saw value in everything and my Grandfather could turn crap into very useful and practical things around the house. I remember he fixed some old clocks that had accumulated in a box. He got them all working and had a pile of parts left over he could never figure out where they went back in. It was the old joke in reality. He started looking at fixing other peoples clocks and very rarely failed and the ones he gave back everyone said they never kept better time. Always had those left over bits though.
The other thing is my sentimentality but getting over that. Not that much left now. Things wear out and have to be chucked. They are not repairable not useful for much else. Pre planned Crap. There are 2 Chairs that came with that lounge I just put out and they will be around for a long time. Even if they cost 4X what I could buy another pair for to recover, I will pay it. I like them, always have and they will stay.
The other thing with my collecting is I HATE having to go buy something to do a project. I want everything I need at hand and build things around what I can put my hands straight on. I have only just got my head around going to the steel joint and actually BUYING the metal I want to do things. I had the arse out my pants a long time and couldn't afford luxuries like that but now I can, old habits still die hard... Like they did with my grandparents.
Out here there are far fewer factories for me to scrounge from within reasonable distance than at the other place that had industrial area's in every direction within about 5-10 Km. Being the genius I am I finally have worked out cheaper to go buy the stuff than waste endless fuel driving round trying to find something to make do.
I still pick up anything that may be useful along the way for next time.
Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1577
Posted: 08:04am 15 Jun 2021
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I am going to also try and automate this a bit with a thermostat. If I set it to 20 or 25C, that should be enough although now I have done a reverse flow setup, that may complicate things a bit.
Maybe I can put it in the panel near the fan and set it high to allow for the direct heating it will get. Other thing might be to put in a PWM or resistance so it just Turns a bit to pull air though and then the thermo ramps it up when it hits temp.
Another thought I had was to try and research if it's possible to take the cells off the glass on a panel. If I could remove the backing and the cells so I just had clear glass, that would be perfect to put over the top to harness the wasted heat that is convected out from the front.
Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1577
Posted: 05:09am 16 Jun 2021
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Got some good sun for a short time today.
I noticed the top of the panel near the air inlet is quite Cool on the front face. It quickly heats up further down and seems consistent. The aluminium frame on the top and the sides at the top are also quite cool and also warm up a short way down.
This tells me that the air is hitting the back of the panel in the inlet area where the gap but might not be so much further down. I think I'll have to try and get some 25mm Aluminium angle and put that on the back of the ply so the air has to pass over it and is narrowed near the panel so it picks up more heat.
I was sitting here earlier and heard a strange Droning sound. At first I though it might have been some large aircraft at the local airport doing a Run up but it went too long. went out to get a Coffee and I could then tell it wasn't a plane and traced the noise down to the panel.
Seems like the bearings in the little Bilge blower have gone. Vibrates and droned when it's off the panel but of course Drums quite (un)impressively when it's attached. I have had the thing a good many years but never used it very much. Certainly not built like the car radiator fans I have that have done years of running every day literally and are still fine. maybe housing or Cutting down one of those to use with this setup would be the way to go?
I might have to Build a box for the cabin blower fan insert I have. That might be better set up just as a blower so I can hook 2 panels together and run them both off the same fan.
Also need to work out how to use the power the panels are generating in additional heat building load to make the most of the electric power generated.
I did see a Brief High of 29O today at the output but after seeing how the panel is cooling near the air inlet then is so warm all the way down, I think there is still heat being not picked up that could be without greatly changing anything. Might be a matter of drilling some small holes every so often down the ply so the air comes in and hits the back of the panel as it seems to be doing at the top.
Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406
Posted: 05:58am 16 Jun 2021
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The fact that its cold means the heat is being sucked out, which is good.
Drilling holes down the ply sounds good too, but I doubt if it will make very much difference to the total heat output, but we shall see.Cheers, Tony.
Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1577
Posted: 10:33pm 16 Jun 2021
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I am in 3 Minds about this myself.
Mike mentioned the lost heat out the front of the panel and I can wellsee how this could happen when the surface is so hot as it stays over all. If it were cooled like that top section, there is much less heat to be lost.
OTOH, if the panel is warm, it may just be like a constant operating temp an the heat that is going to be gained is and that's all there is to it.
There is every reason however to believe that disturbing the air and getting some turbulence happening will pick up more heat. The cooler I can get the panel the more heat is going into the air. Checking it yesterday, I could not dicern by feel the panel I was pulling the air across was any cooler than the ground mount panels sitting next to it. Admittedly they had clear air behind them but they dint not have moving air which in my mind should have made the other one with the blower cooler.
I imagine there are a lot of ways one could test to see what pulled the greatest heat out of the panels but pretty soon one would hit my law of solar that inefficiency in the most efficient in that by the time you improve the output, it's cheaper, easier and better overall just to do nothing and add another panel.
On the scale I'm thinking of an array, the trade off would be the time and effort to connect a bunch of panels Vs. making less panels produce more heat.
I would tend to think sheer Sq. inches will still win out but I'll try some simple methods to improve the individual panel cooling anyway.
Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me.
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