Solar Thermal From Scrap...AGAIN!

[Onoff]

It's finally happening:

 

 

 

Using unistrut instead of proper channel so had to get creative with some 3D printed spacers:

 

 

 

[Pocster]

9yrs ?

[marshian]

51 minutes ago, Pocster said:

9yrs ?

 

Have you fixed your leak yet ? 😉 

[ToughButterCup]

How do you manage the water flow (piping) through the roof membrane(s) ?

[Onoff]

1 hour ago, ToughButterCup said:

How do you manage the water flow (piping) through the roof membrane(s) ?

 

Something like this probably. I'm not BUYING a proper flashing. Going to wet diamond drill the tile and 3D print flashings. All glued down with CT1.

 

 

 

[Onoff]

Would these corrugated stainless pipes do as the interconnects at the top of the panel between panels 1 and 2 then panel 2 and 3?
 

https://ebay.us/m/hHy3Fm

 

 

Various sizes. I presume I just equally space my panels on the rail and pick the right length /end fitting pipe?

 

Then the pipes through the roof at each end of the array, same stuff or copper?

 

A lad I'm talking to on another forum reckons he's used copper throughout, his system has been up and running 12 years with no issues.

[Bramco]

1 hour ago, Onoff said:

A lad I'm talking to on another forum reckons he's used copper throughout, his system has been up and running 12 years with no issues.

If you use copper, use 10mm, it means there is less heated water in the hot pipe, so the heat gets to the coil in the tank quicker. we did this in a previous house and afaik, it's still running after 15 years...  😄

[SteamyTea]

Just make sure all the joints are compression ones. 

I think those stainless, corrugated, pipes are to allow for expansion and movement.

Make the system a drain back one and those problems go away, but gives you other problems.

[Onoff]

11 hours ago, Bramco said:

If you use copper, use 10mm, it means there is less heated water in the hot pipe, so the heat gets to the coil in the tank quicker. we did this in a previous house and afaik, it's still running after 15 years...  😄

 

It'll be pumped, will 15mm make much difference?

[Bramco]

10 hours ago, Onoff said:

 

It'll be pumped, will 15mm make much difference?

 

On our pump controller, the pump only ran when there was enough heat in the header on the solar array. I'm guessing yours will also work this way. So in marginal conditions, it only runs intermittently.

Using a narrower bore means that the hot water will actually get through to the tank. With 15mm or bigger, you can get the situation where a hot slug is pumped into the pipe but never reaches the tank. 

I've not checked but I'm guessing 10mm is also cheaper than 15mm. So probably also a better option if you are on a budget.

 

EDIT

Try this, it has good insulation as well as a cable for the temperature sensor.

https://www.bes.co.uk/solarquip-twin-flex-insulated-solar-pipe-dn16-x-10m-21102/

 

Edited April 22 by Bramco

[Pocster]

11 hours ago, Onoff said:

 

It'll be pumped, will 15mm make much difference?

🙄🙄🙄🙄😉

[Onoff]

11 hours ago, Bramco said:

Try this, it has good insulation as well as a cable for the temperature sensor

 

How much? 😬

[Onoff]

Render of a 3D printed tile flashing. It'll get CT1'd to the tile. A 110mm elbow will sit on top of this:

 

[Nickfromwales]

On 23/04/2026 at 17:24, Onoff said:

A 110mm elbow will sit on top of this:

 

If you put a 110mm elbow on your roof, I'll come down there and multi-tool it back off.

 

Just "NO!". It'll be fugly as feck.

[Onoff]

Prototype flashing for the tube entry:

 

 

 

 

 

[Onoff]

I must have told my lad 110mm internal diameter 🤭 this is mind just a lightweight prototype print:

 

 

That's obviously a 45⁰ bend rather than as 90 but it's just proof of concept. The pipes will run through it within rockwool type insulation.

[Onoff]

Decided I definitely want to get a proper ladder between the panels and at each end. Meant extending the unistrut by 880 mm.

 

 

 

Of course now the end overhang looks a bit silly so I'm debating adding another bracket at each end 

[Dillsue]

If you want a "ladder" so you can climb the roof, just slide every other tile up in a vertical row. Your tiles look exactly the same as ours and sliding them up and out of the way makes a great way to move around.

[Onoff]

😡  In the cold light of day, in fact a cold dark day which matches my mood, I reckon I'm going to have to shift the brackets to offer better support to the extended rails. It's going to mean I think messing around with some ridge tiles on the hips to get the end brackets in on the top rail. Ah well!

4 brackets as is:

 

 

Back to having a centre one and 5 brackets per rail:

 

 

[Onoff]

I'm guessing nobody usually does this but I'm intending "shading" the installed 3 panels temporarily when done with a "99%" solar reflective blanket(s). Probably secured with bungee cords. This so the unfilled panels don't overheat. The idea being I can finish the roof side pretty much, have all the tubes up there, fitted and safely out of the way. Then concentrate on inside the loft which is another mission. I'll fill the system later on.