Removing a Dualstream Accumulator
- Thread starter wysinawyg
- Start date
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G
GeorgeBramwell
What is the main supply like? Pressure? Flow? If poor, try keeping the accumulator and ditching the unvented cylinder to save space. Then install a high flow combo. A 51KW ATAG will do two bathrooms.
D
Deleted member 105431
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Just for everybodys information, GAH also Build the OSO Dualstream,
GAH Owns the Patent for the Dualstream system, which was originally designed by local Essex/Suffolk Contractor Elsey & Bailey.
All Dualstream Ariston/OSO/or Whoever are assembled at The GAH Plant in Woodbridge, Suffolk
GAH Owns the Patent for the Dualstream system, which was originally designed by local Essex/Suffolk Contractor Elsey & Bailey.
All Dualstream Ariston/OSO/or Whoever are assembled at The GAH Plant in Woodbridge, Suffolk
D
Deleted member 105431
Whilst this topic does catch one's attention for a while, it does raise a question for me. I personally think that accumulators are a complete waste of time (I'm based in London). Correct me if I am wrong, but the pressure which they accumulate is according to the highest mains pressure that is provided (normally in the middle of the day or the middle of the night), which they then store. As people tend to use water at certain times (morning & evening showers for example) the mains incoming pressure is significantly lower (and almost non-existing in certain parts of London) at these times. This is where the accumulator is supposed to excel. However... assuming you have 2 bar pressure at best coming into the system, when the pressure drops you should then have 2 bar pressure from your accumulator... for a very short while. In fact I believe the pressure exerted from the accumulator will only give you a few short minutes of water supply, before the pressure equalises with the incoming mains, if any. To get a real benefit from an accumulator I think it should be at least a 1000 litre capacity. And who has the space for that? Am I incorrect? And should I have posted this in the GSR (registered) area?
You're wrong.
They can be set up in this way, or in some cases you might fit a pressure reducing valve to prevent this, depending on the local conditions.
An accumulator will stabilise at the highest pressure but this is not the primary advantage of fitting one.
In fact you believe? Or do you believe in fact? The facts are that the accumulator is not about boosting static pressure, it is about boosting flow rate.
Out of the hundreds of accumulators we have fitted, I can only think of two instances where more than a 500 litre gross volume (250 Litre stored water) was needed, and they were VERY large houses (one had 12 bedrooms).
The Romans invented accumulators, they must have understood pressure and flow better than you. You have ignored dynamic pressure, which delivers a higher flow rate. Accumulators work because you are removing the pipe restriction between the source of the water and the point of use. In other words, the reservoir and the tap.
Whether or not a patent should have been granted around ten years back to define the use of a 1000 yr old design in domestic water systems in the UK is debatable; but there is no doubt that they work. Extremely well in the right application.
The pros and cons, together with some ill informed scepticism, were debated ad infinitum on this forum a year or two back. I took a good leathering here but stood my ground. There is no point starting again, do a search and make your own mind up.
The facts are that the accumulator is not about boosting static pressure, it is about boosting flow rate.
I am quite pleased to meet someone who understands the difference between pressure and flow rate. That said; if, for example you install an accumulator of 50 Litre capacity, (that being the water capacity) and assuming the remainder of the cylinder is 25 Litres, which can then be compressed by the supply pressure, be it mains or boosted, would the output of the cylinder not be only 50 Litres, with the flow rate reducing litre by litre until the last litre when the pressure from the accumulator would be 'spent'? (Taking out the factor of either the mains incoming or boosted supplies)
I am quite pleased to meet someone who understands the difference between pressure and flow rate. That said; if, for example you install an accumulator of 50 Litre capacity, (that being the water capacity) and assuming the remainder of the cylinder is 25 Litres, which can then be compressed by the supply pressure, be it mains or boosted, would the output of the cylinder not be only 50 Litres, with the flow rate reducing litre by litre until the last litre when the pressure from the accumulator would be 'spent'? (Taking out the factor of either the mains incoming or boosted supplies)
I'm not sure I understand the question, which reads a little ambiguously.
The accumulator works best if the air and water, when the unit is under load, is approximately 50/50 ratio in volume. Therefore, broadly speaking, a 50 litre water accumulator would use a 100 litre volume vessel.
In your scenario the output of the unit would be 50 litres. If you connected your puny 50 litre unit to a 9 litres per min water supply, you could enjoy a 20 litres per min shower for two minutes (depending on static pressure etc there are a few variables here).
But this is like designing a rechargeable battery that only lasts 3 minutes.
Accumulators designed for water boosting are generally specified with 120-225 litres of water, thus they are capable of delivering a massively boosted water supply for useful durations.
We use our hot and cold water in 'bursty' periods, and bearing in mind most accumulators have recharged themselves in just 20-30 minutes, they are a useful weapon in a central heating specifier's armoury.
The accumulator works best if the air and water, when the unit is under load, is approximately 50/50 ratio in volume. Therefore, broadly speaking, a 50 litre water accumulator would use a 100 litre volume vessel.
In your scenario the output of the unit would be 50 litres. If you connected your puny 50 litre unit to a 9 litres per min water supply, you could enjoy a 20 litres per min shower for two minutes (depending on static pressure etc there are a few variables here).
But this is like designing a rechargeable battery that only lasts 3 minutes.
Accumulators designed for water boosting are generally specified with 120-225 litres of water, thus they are capable of delivering a massively boosted water supply for useful durations.
We use our hot and cold water in 'bursty' periods, and bearing in mind most accumulators have recharged themselves in just 20-30 minutes, they are a useful weapon in a central heating specifier's armoury.
Thanks AlanE, I do actually appreciate the comments telling me not to touch as much as the ones telling me its fine.
I'm not looking for a final decision on this, just looking to understand what the important elements are so I can make an informed decision on whether or not I do need an expert in.
I think I've got that such that the conclusion is that turning off an expansion vessel which is part of the unvented system is a bad idea but turning off an accumulator which is incapable of acting as an expansion vessel is no different to changing or removing a tap.
No question its then down to me to decide if I know for sure which I have and to call someone if I don't.
As it is the system isn't connected as per either of the diagrams as the installer didn't split the combination valve as shown in the diagrams, but I'm happy that I understand enough about this now to work out how my system is connected.
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