 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. |
Forum Index : Solar : Deciding if I should build this solar heater
  Page 40 of 40 |
|||||
| Author | Message | ||||
| Godoh Guru  Joined: 26/09/2020 Location: AustraliaPosts: 524 |
Hi Roger that looks great, the sheet metal work looks fine. When we don't have a bender or pan brake to work with, well improvisation is the way. Things are only wrong if they don't work and that looks like it will work fine fantastic project. I hope you get enough sunshine in winter where you are for it to save a lot of heating bills pete |
||||
| rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 901 |
Thanks Pete. Yeah I was very happy with how it turned out and think it will do the job ok. I keep looking at folders and guillotines etc ... but I'd use them that rarely I really can't justify buying one ... and then have to find room to keep them between uses. I'm very confident of enough sunshine during winter to make this worthwhile. The original prototype is into its 5th season of use already and still does a great job. I cant wait to try this one out and see what she'll do ... especially seeing it's over three times bigger. Hopefully it won't be an anti climax.  Cheers, Roger |
||||
| Godoh Guru Joined: 26/09/2020 Location: AustraliaPosts: 524 |
Hi Roger, I made a small sheet metal folder from scraps of steel I had lying about. It is bolted to my bench, it only does metal up to 600mm long but has had quite a bit of use. I find it really handy. I just used a heavy piece of angle iron for the base. And another piece for the folder with two pieces of pipe welded on for handles. Good luck with getting the heater installed. Pete |
||||
| rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 901 |
Yeah I'd often thought of building one too ... but have so many of those projects in my mind and a heap of others half done and abandoned. When I've finished my generator off and this air heater, maybe I could tackle it. We're gonna need heat sooner than later ... so the heater is top priority at the moment. And some good news ... I heard of another crane guy one town over, who only charges $125/hr and who likes cash, so is negotiable ... especially if he has a couple jobs to do over here ... so it sounds like it might be a lot more reasonable to have it craned on. Cheers, Roger |
||||
| Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1584 |
Great progress mate. 20 Kw is substantial heating power and even if it's a bit overcast and you only get 10KW, between this and the solar you won't be cold. I had my Ducted AC replaced about 2.5 years ago. The old one was still working byut was undersized for the house to begin with.... typical of the guy that built the place whom we bought it off. It was useless in winter and being the only real heating, was not good. Would just freeze up and run flat out doing nothing. I got the largest samsung they make in single phase which pulls a max of 5 KW on the AC side. It was recommended as an alternative by my mate who does AC to Fujitsu or Daiken. Been very happy with it and I said to my mate, only seems to use about 2/3rds the power of the old one which he said would be about right with the better efficiency. Even on 45o days it will make the house too cold if you crank the cold out the thing. I'm glad to see this finally coming together. If the prototype hadn't worked so well you would have done it sooner! :0) Are you going to leave the small one in place and run them together or does that have to come down? |
||||
| rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 901 |
Thanks Dave, and good to see you here again. If I had unlimited funds I'd replace the aircon straight away and see how well the heating works ... but seeing I'm in this deep with this unit I need to see it out. And you're correct, if the old one didn't work as well as it does ... I'd have had to do something sooner ... or keep with the wood. Speaking of wood, I lit the fire for the first time this season on Sunday ... so we've got this far into the season with just the air heater, underfloor heating via solar plus a couple of normal resistance heaters. And all off-grid at that too. Yesterday I poured 32kWh into just the floor alone ... plus had the two 2,300 watt heaters running for the same time. I had a couple of wifi switches put in the meter box so I can turn them on or off from the workshop. Very handy ... and they also monitor the power useage. Both are 3,000 watts. In the month the switches have been in, we've used 153kWh for the floor alone. My plan with the original was to transfer it to the workshop. Just hang it vertically on the wall and cut a 6" hole either end for 90 degree elbows. I had started to think that with all this solar I'd just use a reverse cycle aircon ... but with just 43 watts for the original airheater fan ... and the fact it runs as soon as the sun shows up ... often at 7.30 am ... I have to try it there as well. Of course I have to rebuild it because it is fairly badly distorted. I can't remember who it was (haha) but someone suggested I run it on a hot day to see what sort of heat it would put out ... and of course being pretty gullible I decided to give it a try. One hot day I ran it for a minute or so and was surprised that it wasn't any hotter than I'd seen before ... so a bit of an anticlimax. Anyway a few weeks later I walked past and noticed the endcap off the hot mainfold was lying on the ground. Once I looked at it, the tube had collapsed by a couple inches from just that minute or so of heat and with the cap popped off was just pumping outside air into the room. I thought it was stuffed, but when the cool season turned up, I just taped it up and kept it going. Not too much later, from the pressure of everything being out of alighnment, one of the tubes broke ... but with my excellent taping skills, I had it bypassed in no time.  The lower pipe used to be the same shape as the top one.   Edited 2025-06-05 10:11 by rogerdw Cheers, Roger |
||||
| rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 901 |
I've got a few projects on the go at the moment ... and waiting for a young fella who has been promising for weeks to finish bending up the cowls to go over my inlet and outlet ducts ... plus I've been dragging my feet on tackling the mounting system for the roof ... but finally today I actually made some progress. The whole assembly is 4 mtr x 2.4 mtr ... and so it will straddle 8 rafters. I bought some 200mm x 10mm stainless steel anchor bolts which have a coach screw thread at one end and metal thread at the other ... with a rubber grommet in the middle to seal where they come through the tiles.  I bought a batch of 5 diamond encrusted 16mm bits to drill through the tiles ... ~$20 from aliexpress ... as against ~$60 for one from Bunnings. I practised on a spare tile and was amazed at how efficient it all was. Certainly worked better by consistently spraying with water to lube and cool. I was on my third bit by the time I finished the 16 holes, so very relieved I bought the five. The corner bolts are not meant to be aligned with the side ones.  The next items on my shopping list are a couple of 250mm Dektites for where the inlet and outlet ducts go through the tiles. Special order from Bunno's. And I also plan on adding some extra support struts below the mounting points to help with the load. The bottom row is just above a wall, so will only need a couple feet of timber for each of those. The higher end will need some triangulation, but shouldn't be too difficult. All up will be around 300kg ... so approx 20kg per mounting point. Winter will probably be over by the time it gets on the roof ... but hopefully will get years of use from it once it's up there. At least I know the concept works as our original one is still going strong ... and just recently I came across a video of a Chinese firm that is selling the exact same thing. I'm not sure what it was heating ... but one shot showed about 20 of their units, each with 50 tubes, all on the roof of some building. 20x50 tubes = 1000 tubes!!! And there were several other shots with multiples of the units all together ... so they are clearly building and selling them. Wonder if they've been visiting the back shed? Edited 2025-06-21 20:21 by rogerdw Cheers, Roger |
||||
| Godoh Guru Joined: 26/09/2020 Location: AustraliaPosts: 524 |
looks good Roger. I have a set of carborundum hole saws that I use for ceramic tiles, they would probably work good on roof tiles too. I used to just drill tiles with a sharpened tungsten drill, but it had to be done carefully as old tiles crack really easy. The diamond tipped drill looks like it does a good job. Maybe the chinese company saw your early iteration and copied it. They seem to be pretty fast at that stuff Pete |
||||
Bryan1 Guru Joined: 22/02/2006 Location: AustraliaPosts: 1424 |
Hi Roger you probably already know this but with SS threaded parts they are prone to galling so make sure you put some lube on the threads  The last you need is a stuck nut on the installation.Now if need hand on installation date just sing out mate as I'm happy to help. Regards Bryan |
||||
| rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 901 |
Thanks Pete, I'd never tackled drilling tiles before so was a little worried, but these things did a great job. Just glad I bought a few spare bits ... and also have a great heap of spare tiles. I looked up carborundum hole saws and they look very similar to the ones I bought, except aliexpress claim their's are diamond tipped. My comments about the design being copied were a bit tongue in cheek though it is possible I suppose. I always remember the comments about the Power Jack idle power reduction mods appearing in the factory ones after guys here fine tuned them by using a choke etc (if I remember correctly). The best part is that it gives me more confidence that the idea is worthwhile because others are doing the same thing but on a commercial level and much greater scale. Cheers, Roger |
||||
| rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 901 |
Hi Bryan, and no I had never even heard of galling with SS threaded parts. I've probably experienced it at some stage but never knew it was a thing ... thanks for the heads up. What lube would you recommend using or isn't it really important what type as long as there's something. And thanks for the offer of help with installation. I do plan on hiring a crane for the lifting ... but could certainly do with an extra man on the roof making sure it locates properly as it's lowered. I'll let you know as it gets closer and see if we can make a time that suits. Thanks again. I am feeling a lot more confident now I have all the anchor bolts in place and just need to cut up and weld together the angle brackets that will sit on the bolts, so the frame can be lowered onto them. Then I can drill through the sides of the frame and stick some bolts through. I managed to get four support timbers in for the higher side ... and was surprised and really pleased that there is a wall directly below, that the struts rest on. I'm hoping I actually planned that but can't really remember, it was so long ago when I was crawling around in the ceiling trying to work out just where to locate everything. I haven't tackled the lower end yet but they need timber about 900mm long on a bit of an angle to another wall frame. Should be easy enough to do that next weekend. It's not a good photo, but the anchor bolts are located directly above the studs ... and the bottom ends are resting on the wall frame. The closest one looks like it's on a bit of a lean ... but they were all dead vertical according to the spirit level. Must be the optics.  Edited 2025-06-23 00:50 by rogerdw Cheers, Roger |
||||
| Godoh Guru Joined: 26/09/2020 Location: AustraliaPosts: 524 |
Roger what I use on solar rack bolts and fittings it called Nickle Seize. Stainless steel as Bryan said does gall. Old solar rack bolts are almost impossible to remove after a few years. So I put nickle seize on the threads and have found it works well. I use it on any stainless steel bolts especially on motorcycle engine bolts. Pete |
||||
| Bryan1 Guru Joined: 22/02/2006 Location: AustraliaPosts: 1424 |
Roger I do have several tubs of never seize here so the next time I'm going to the Bridge I'll drop a tub off to you |
||||
| rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 901 |
Thanks Pete. I guess that's what was wrong with a heap of solar fittings I couldn't dismantle when I wanted to reuse it. I just assumed there was a mismatch of materials ... but was probably this galling you're talking about. And thanks Bryan, that would be very useful. Hopefully once it's up there it won't need to be altered in my lifetime, but you never know. I do wonder now about all the railing and fittings I used when I put up all my panels ... I just put them all together dry. Hopefully I won't need to make any changes there. Cheers, Roger |
||||
| Solar Mike Guru Joined: 08/02/2015 Location: New ZealandPosts: 1162 |
I would recomend LanoCote available from Bunnings for use on all solar fittings, stainless bolts etc, just spray it on; years later you wil be able to pull things apart again. LanoCote Cheers Mike |
||||
| Bryan1 Guru Joined: 22/02/2006 Location: AustraliaPosts: 1424 |
Roger looking at that Lanocote Mike mentioned sounds like the best solution and I'm even going to get a can for myself. The beauty about lanolin spray it does get in and stays there and being a spray can with a fine nozzle will make it a breeze, even with your existing solar array a quick spray where the bolt goes into the base block will do wonders for undoing it down the track. The main problem with old style never seize it does get everywhere and makes a mess so a spray can does look the best solution. Regards Bryan Edited 2025-06-25 09:57 by Bryan1 |
||||
| rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 901 |
Thanks Mike, a spray does sound good and it looks like something really useful to have on the shelf. Yeah, after seeing Mike's suggestion I figured I'd grab some too ... and this job should be a good test for it too. Thanks. Cheers, Roger |
||||
| Page 40 of 40 |
|||||
 Print this page |
 |
The Back Shed's forum code is written, and hosted, in Australia. | © JAQ Software 2025 |
