New combi sizing - overspecced??!
- Thread starter Phil12345
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As a rough experiment, if you have a garden tap and hose, you could run the hose to where your shower head is and attach the shower head to the hose in situ... See what you get out of the shower at that locale... Get under it if you're brave enough 
There will be a difference between this and the result following system install due to pipe runs etc, more if it has to be instantly heated through a combi plate hx but it should give you a practical over theoretical idea of what to expect!
There will be a difference between this and the result following system install due to pipe runs etc, more if it has to be instantly heated through a combi plate hx but it should give you a practical over theoretical idea of what to expect!
Double post!
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Static pressure and open pipe flow rate are little use in predicting how any installation will perform. They cannot exist together!
When you make measurements you need to measure the flow rate whilst still having 1.0 bar pressure in the pipework as measured at your garden tap.
Tony
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I think you may need to think/study more on pressure and flow measurements.
Absolutely tony and I have got no idea!
I guess what I'm looking for is a definitive answer on what I can have and 50%of qualified people insist I have and 50% of people insist I haven't.
That's why I guess I feel like it's my job to work it out as none of those people will care if one or t'other gets installed and it doesn't work properly! The old "looks ok from my house!"
I'm all for the registered time served and qualified guys doing the job but I've not found one tht can tell me definitively what I can have! Everyone swears they are right!
I guess what I'm looking for is a definitive answer on what I can have and 50%of qualified people insist I have and 50% of people insist I haven't.
That's why I guess I feel like it's my job to work it out as none of those people will care if one or t'other gets installed and it doesn't work properly! The old "looks ok from my house!"
I'm all for the registered time served and qualified guys doing the job but I've not found one tht can tell me definitively what I can have! Everyone swears they are right!
I think that you should be looking at manufacturers and their system requirements and work backwards from there! After all, it's you who will be getting under that shower, not you chosen installer! One man's pleasure is another's pain and all that!
There's all the technical info you need for unvented cylinder manufacturers and combis online, and you could speak to them.
But, if your incoming supplies are borderline... Any potential specifier/fitter is going to be nervous about fulfilling your expectations.
I don't agree with that!
Unfortunately there are many in this trade who will give you a written quote for installing something.
You accept and they install it and you are not happy with the performance.
They reply that YOU accepted the quote and so you have to pay for it. Which legally you will.
There is a solution, but no one usually does that.
It is to PAY someone to design the system for you!
Tony
From the rather garbled measurement data here it seems the only meaningful measurement you have is 11 li/min @ 1.0 bar.
The recommended minimum is 22 li/min @ 1.0 bar
But a static pressure of 3 bar is pretty good and at only perhaps 20% of homes.
It would mean that an accumulator would work well if all else failed.
Tony
The recommended minimum is 22 li/min @ 1.0 bar
But a static pressure of 3 bar is pretty good and at only perhaps 20% of homes.
It would mean that an accumulator would work well if all else failed.
Tony
You know what tony? I would do that I think.
As a service time and effort wise what would that price be?
Because no one has offered and no one has even suggested it. And in reality it's the job I'm tryin to do now with Jack all knowledge so it's a service I need and would pay for I think. I've not had anyone read te garden tap at 1bar but the open flow was 30% higher than kitchen which suggests there may be some hope
As a service time and effort wise what would that price be?
Because no one has offered and no one has even suggested it. And in reality it's the job I'm tryin to do now with Jack all knowledge so it's a service I need and would pay for I think. I've not had anyone read te garden tap at 1bar but the open flow was 30% higher than kitchen which suggests there may be some hope
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What do you play mate? Any youtube vids of the band?
Sorry for being a nosey bstard! Just interested!
And that's the thing tony I look at my 11 vs minimum 22 and think that's £3000 spent and I know it's half of what I need at the outset!
I saw you went somewhere recently where an unvented was put in on a 12l flow and you said was totally unsuitable!
I saw you went somewhere recently where an unvented was put in on a 12l flow and you said was totally unsuitable!
Hi TCC. I play bass in a Soul band. I'll sort some links if you're interested.
You've quoted me out of context Tony, I prefixed that comment with "but if your incoming supplies are borderline..."
However, I do agree with what you're saying about many not caring! I do, as I'm sure you do also. As for the OP... In the words of Andy Capp... "It's all over, flow!"
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