On 30/04/2019 15:45, Jethro_uk wrote:
On Tue, 30 Apr 2019 15:02:32 +0100, Steve Walker wrote:

On 30/04/2019 14:33, Jethro_uk wrote:
On Tue, 30 Apr 2019 14:07:53 +0100, Brian Gaff wrote:

A friend has those water panels on her roof and has told me it saves a
lot of money on bills for heating water. I guess its lower tech though
and lets face it many like the idea of gadgetry!

I think it's quite high tech, if you are using the vacuum tubey things


My primary concerns are about getting what must be quite a weight of
water onto the roof, and the potential for burst pipes. Although I
guess if your roof is doing it's job, a leaky setup should be no worry.

There's not much weight - at least with the systems that I looked into.
The tubes contain little water and there is a separate insulated tank,
which can be inside.

A small pump pushes water from the bottom of the tank, into the bottom
of the collectors and it returns to the tank from the top. The small
volume, low flow, lets the water get very hot before returning.
The pump flow can be automatically varied to give slower flow when there
is less sunlight and so maintain a high return temperature.

When there is insufficient sunlight, the pump stops and the water drains
back down to the tank (preventing freezing in the tubes). The pump can
also be stopped if the tank is getting too hot to prevent boiling in the
tubes.

I looked into buying the bits separately and making my own control
system. I did come up with a simple control circuit and software design
when I was looking into it, but I don't think I kept it when I didn't
take things any further.

SteveW

On topic: check.
Useful info: check.
No personal abuse: check.
Adds to discussion: check.

You really need to work at this newsgroup thing, mate. It may not be for
you.

Oh don't worry, I occassionally dabble in the various Brexit threads.

SteveW