On Wed, 04 Oct 2006 01:23:49 +0100 someone who may be The Natural Philosopher wrote this:-
I'll ignore the parts of your posting that are another personal attack. Readers can make up their minds about how to treat your postings.
The bit that is worth replying to is quoted above. It assumes that everyone who uses a bath or shower is sprightly. However, not everyone is.
Thereby simulating a combi boiler.
You can't have *water* coming out of a shower at 120C, it becomes steam at 100C at atmospheric pressure.
Yes you can. When it is in the pipe, it is pressurised. It takes a finite time for it to evaporate when it emerges into atmospheric pressure.
Christian.
But the issue here is one of using a hot water TANK on UNPRESSURISED hot water supply from a CISTERN type header tank.
As usual we have weaseling from those who realise what asses they are making of themselves.
Well that's what you're thinking of. I'm thinking of a malfunctioning system that has boiled and gone overpressure with a malfunctioning vent. After all, why else would the water be at 120C?
Christian.
Have you any idea what pressure you need to maintain water at 120C?
ok ;-) Never realised what my post would start, anyway, thanks for the replies. It looks like however unlikely, a sensible way is to cold from the header tank. Should this be in 22mm pipes like the hot? I'll have to lay pipes in the loft, above or below insulation?
About 28 psi or 2 bar according to
On 04 Oct 2006 08:20:36 GMT someone who may be snipped-for-privacy@isbd.co.uk wrote this:-
Look at my original posting and note that I didn't claim any such thing.
What I did say is that it is not just water at 120C that kills people. Water at more modest temperatures has killed people.
Yes 2 bar, i.e. 1 bar more than atmospheric pressure, which is approximately the maximum allowed working pressure for many vented hot water cylinders, so would be unlikely to cause rupture in itself.
Christian.
On 4 Oct 2006 04:13:05 -0700 someone who may be "Spat" wrote this:-
Yes, especially if the shower has a minimal head. It reduces pressure losses and so gives a better shower. While gravity showers with 15mm piping can be made satisfactory it is best to use 22mm.
Depends on the way the joists run, pipe length, insulation depth, insulation type and a few other things. However, generally they are run above the insulation. Make sure the pipe itself is insulated.
:-)
You're stretching things a bit there, if I say it's "not just smorfolideonge" that kills people then there is at least an implication that there is such a thing as smorfolideonge.
The message from snipped-for-privacy@isbd.co.uk contains these words:
You could pressurise the shower stall.
I don't see how a pipe connected to a cylinder connected to a header tank which is open at the top CAN go 'overpressure'
Yup 22mm.
Below insulation probably simply to avoid possible freezing.
I would thing that the 2 bar pressure necessary to get the water to 120C and in contact with someones skin without turning to vapour would be pretty debilitating if maintained for any length of time.
You could live in a yellow submarine too.
About 20psi or 1.3 bar.
On 04 Oct 2006 13:23:23 GMT someone who may be snipped-for-privacy@isbd.co.uk wrote this:-
I'm not stretching things at all.
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