Solar Water Heater MK2

[Bill]

Remember my first attempt at this that destroyed itself by melting when power was accidentally turned off on a hot day. Well, here’s the Mk2 version finally up on the roof and appearing to be working quite well as can be seen from the ice melt around it. The heating coil topped out at nearly 65 C (150 F) while the air temperature was barely above freezing.

There’s still a lot of work to do to increase its efficiency and reduce power consumption but it’s a good second start.

  Someone's gota save the planet! 😊

Bill

[Bill]

Yesterday’s success was a bit short lived; it handled the cold well, but it didn’t like the heavy rain today. (Draught excluder doesn’t keep water out.) Plus, it was turning into a bloomin game of snakes and ladders and climbing onto a slippery roof while carrying my new laptop was a bit dangerous because I’ve not had it long. 😊

Anyway, the plan now is to rewrite the software so that I can tweak the settings and debug things from the comfort of my den. I should have done this in the first place but was a bit too eager to try things out.

Ah well, another day another bug to fix. It’s getting a bit like Groundhog Day, but that’s life for me these days during the pandemic. 😊

 

Bill 😊

[Evil Sid]

Every problem solved is a step closer to the next problem.

Any engineer will tell you that in some form or another, that's why big firms have research and development teams. Not to solve the problems but explain what went wrong this time.....

[Bill]

The problem turned out to be that the plywood I’d used had warped and was causing some very slight rotational tight spots which my software interpreted as a stalled motor. Changing the setting solved the problem for now, but the whole assembly needs completely remaking with weather resistant material and that’s a big job. ☹

 

Bill 😊

[Evil Sid]

Would thick plastic be a viable option or is there too much heat produced.

Thinking along the lines of the stuff they use to cover the wood where the gutter fits.

Two piece joined in the middle would also provide a small gap underneath for when it rains.

[Bill]

That stuff only comes in relatively narrow strips Sid and isn’t really that strong when it’s not screwed onto a solid surface. I was thinking of saving the planet and using something like 12mm Stokbord  (recycled plastic sheet) which is more expensive than plywood but has all the right attributes.

I’ve got a mate who’s just bought himself a CNC router to play with so I might take my Micky Mouse design and redo it properly using CAD software then if I get it wrong again it’s not a major problem to remake another. And the best thing about doing it this way is he does all the work and it only costs me a couple of pints.

 

Bill 😊

[Bill]

The latest update on my little project is that I’ve managed to make the solar collector assembly fully programable so that I don’t need to keep climbing onto the roof to make changes. At the same time, I’ve incorporated a wind gust detector that puts it into a horizontal orientation to minimise the chance of it getting blown away in the event of winds like we had a couple of weeks ago.

The task now is to construct a new indoor water storage unit that’s acceptable to Mrs Green as the old one was made from bits of old decking boards and looked like a badly made dog kennel.

 

Bill 😊

[Evil Sid]

nowt a coat of black gloss won't sort out......