How safe is it to just disconnect solar circuit while relocating cylinders?

[BarryEverett]

Hi,

I'm having an extension done, and need to move my existing solar cylinders. Currently I have solar tubes on the roof (scaffolding required to get to them!) so don't really want to have to touch them. Can I just drain it down, move the cylinders, and then connect all up again and refill? It'll take a day or two to move the cylinders and boiler and redo all the pipework, so was concerned about the tubes overheating? or do I need to get up there and cover them up?!

Cheers,

Barry.

[Naptown]

Just drain them down.
try to have as much of the piping in place that you can before draining down to shorten the time but a day or two own't hurt. In fact we have Evac tube systems in place for space heating applications and they are drained down all summer long
When you do refill don't do it in the afternoon either very early in the morning or well after dark.

[BarryEverett]

wow! that was quick. good stuff. thanks.

Out of interest, is it easy enough to refill? and what kind of pressure would you expect? From memory I think my system is showing only about 2 bar, so I'd just do what it is at the moment, but wondered what the recommended/usual pressure would be.

It's also needing a bit of redesign. think I'll post another question for that! It's actually quite complicated with 80 tubes, hot water, underfloor heating, and 2 x 300L cylinders! and I'm not getting the performance I'd expect.

[Naptown]

you will need a pump capable of pumping up to the highest point on the headers.
Being american I don't do Bar measurements but a general rule of thumb is one pound of pressure for each foot of head.
I'm sure you can find a conversion table for these.

[BarryEverett]

thanks

[peakbagger]

A minor correction - 1 PSI is equal to 2.31 feet of water at 60 degrees F. Years of pump head calcs have burned it into my mind.

[russ]

Unless you have a very tall house or piping with too many bends or too small diameter 2 bar may well be adequate - 30 psig for all purposes.

[BarryEverett]

Thanks again. I had a quick look, and found google does the conversion for you "1 bar in psi", or few seconds search, it's about 1 bar = 14.5 psi. approx.

Looking at the gauge I have, it's currently running at a bit less than 1.5 bar (approx 22psi). The green bit of the gauge goes from 1-3bar (15-45psi then).

It's an old old Victorian town house, 3 floors, so yes it's tall! I'll not worry about it. The main thing was the disconnect/reconnect...

Cheers,

Barry.