Thermal Store or Heatbank???

[DeltaT2]

I wonder if anyone can tell me when these sludge buckets will be banned from the British Plumbing systems??

 

[ALEC1]

ASAP I hope...

Buffer vessels are a different issue though!

 

[Dan Robinson]

Yawn.

 

[SimonH2]

I wonder if anyone can tell me when these sludge buckets will be banned from the British Plumbing systems??

When combi boilers and other equally useless and inappropriate options are also banned ?

Your attitude simply proved that no advice you give can be trusted - because you freely admit that you could not consider options which (contrary to your statements) do have valid applications. If someone stated that there is no place or situation where a (for example) combi could be considered suitable, I think you would suggest they aren't fit to be giving advice since that competence would require them to be capable of making an objective choice of what is right for the specific application.

I'm very happy with mine, it's far better and more reliable that the alternatives that might be used in it's place.

 

[DeltaT2]

I wonder if anyone can tell me when these sludge buckets will be banned from the British Plumbing systems??

When combi boilers and other equally useless and inappropriate options are also banned ?

Your attitude simply proved that no advice you give can be trusted - because you freely admit that you could not consider options which (contrary to your statements) do have valid applications. If someone stated that there is no place or situation where a (for example) combi could be considered suitable, I think you would suggest they aren't fit to be giving advice since that competence would require them to be capable of making an objective choice of what is right for the specific application.

I'm very happy with mine, it's far better and more reliable that the alternatives that might be used in it's place.

Simon, for starters this thread is a joke, in a vain attempt to flush out Water Systems aka Dr Drivel..........etc, etc. Granted it's childish.

Now as for your attack on my abilities, would you please contact me via PM if you have a problem with my input on anything. Can I suggest you are like many on here, you've too much time on your hands and very little practical experience.

Take for example your last sentence above, you have clearly fitted one or a limited number of sludge buckets, where as we have removed 100s & fitted a few.

 

[SimonH2]

Now as for your attack on my abilities ...

I speak as I see. If you don't like what I see, then perhaps you should consider why that might be.

I also assume you've also removed quite a lot of failed DHW cylinders, and failed condensing boilers, and ... Perhaps the thermal stores and heat banks you've removed were not properly chosen, or weren't the best option for where they were used, but that's not an excuse for your blanket "can't ever be any good" attitude. The fact that you install few says nothing more than either a) you decided it wasn't the right choice for the situation, or (I suspect more likely) b) you won't install them unless there isn't an alternative - hence the lack of numbers you install doesn't really say much at all about them as a technology.

Even the term "sludge bucket" shows a deep bias. If there's sludge in the system, then perhaps having a large cylinder it can settle out in without causing any problem is better than it building up in ... ooh ... say, the radiator bottoms. I've never taken a rad off without there being black sludge in the bottom of it - so are all rads sludge buckets and something to be avoided ?

Lastly, and this isn't aimed at you, but a lot of anti-store crap is spouted by plumbers who - whilst they may be very good at installing pipework - clearly haven't a clue how anything but an S-plan system works (and have no interest in extending that knowledge). A classic example is the oft quoted "fact" that boilers won't condense if reheating a store - if a boiler isn't condensing virtually all the time doing that, then the system was either designed badly, installed badly, or not set up correctly. Though as I've already mentioned, the pish poor design of many boilers (or at least the "unimaginative" limitations placed on their use in the MIs) doesn't help. I'd expect any boiler to condense nicely (and be running efficiently) with a return temp of (say) 30˚C (or lower).


Now, it's no secret that I "quite dislike" combi boilers. Whilst I'd need a very good reason to have one in my house, that doesn't mean I can't see that they have their uses - and accept that many people are quite happy with them (have they ever experienced anything else ?). Similarly, I don't suggest a thermal store or heat bank is for everyone. Perhaps you ought to be a bit more flexible in your views ?

 

[DeltaT2]

The few sludge buckets that we've installed mate, have been in multi-heat source installations, and they have worked very well, but as documented, you need about 25% inhibitor in these systems. So, at the end of the day they're sludge buckets, purely by the fact 1000s have been removed - now that's a fact.

Now, as you have insulted me & my ability, I'd like to meet you, so I still await your PM or apology.

 

[SimonH2]

The few sludge buckets that we've installed mate, have been in multi-heat source installations, and they have worked very well

So now you are backtracking and saying they can work in a properly designed system ?

So, at the end of the day they're sludge buckets

Derogatory term

, purely by the fact 1000s have been removed - now that's a fact.

Err, one does not lead to the other. It may be a fact that 1000s have been removed, that doesn't make "sludge bucket" into a fact - it remains a derogatory term which shows you are prejudiced against them.

Now, as you have insulted me & my ability, I'd like to meet you, so I still await your PM or apology.

Apologise for pointing out your attitude ?

We aren't likely to meet. It's a while since I've been north of the border, and I've no plans to be that way in the forseeable future - and I don't expect you have plans to be down here either.

 

[highleigh]

While we're on the subject of systems that clearly do not fall into conventional wisdom what about running radiators upstairs and underfloor heating downstairs. As a novice this seems never to be discussed and I genuinely am interested in opinions. Just to add a bit a controversy lets say I have one of those damned sludge buckets that will supply a flow at circa 55 degrees.

Here are the practical options as I see them:

- throw it all away - get a modulating super boiler that drives everything and automagically saves me money because it it just does it. Not really practical but I sure some will suggest it.

- radiators and store driven off boiler direct, hot water and ufh supplied from store at low temperatures - lets assume that the store does stratification, x plate heat transfer and all that clever stuff that makes it efficient.

- as above but oversized radiators supplied by low temperature flow.

- as above but smaller clever radiators which have dynamic boost.

Just to prove I am completely mad this is all in a detached solid brick house that one day may get EWI and could have a whole house heat recovery system.

 

[SimonH2]

Here are the practical options as I see them:

- throw it all away - get a modulating super boiler that drives everything and automagically saves me money because it it just does it. Not really practical but I sure some will suggest it.

Yes, a lot of plumbers (as in people who can put pipework together, not people who can design systems) will suggest that. Bear in mind that if you do away with your cylinder, you will have a combi boiler. So : shower that stops when someone turns on the kitchen tap, bath that takes 20 minutes to fill to usable depth, up to a minute delay between turning on tap and getting hot water if the boiler's gone cold, ... and for good measure, no hot water (and no provision for backup) when it breaks down.

- radiators and store driven off boiler direct, hot water and ufh supplied from store at low temperatures - lets assume that the store does stratification, x plate heat transfer and all that clever stuff that makes it efficient.

Why not just run the UFH off the store as well ?
It does depend on whether you have a thermal store (internal coil) or heat bank (external PHE), but certainly for a TS, you'll have a gradient down the store. Tap off for the rads about 1/3 down, and for the UFH a bit lower still. The hottest water will first have a go at heating the DHW, as you go down, it will have cooled from doing that and you can give it a couple more uses (rads and UFH) before it goes back through the boiler.

- as above but oversized radiators supplied by low temperature flow.

That would be an option - if it suits your situation. It would also mean not having high temperature surfaces that could cause burns, or at least reducing the risk (Google search)


Of course, we both know that according to "accepted facts" here, neither your existing store, nor mine, nor my brother's, can possibly still be working as they'll have clogged with sludge ages ago.

 

[Dan Robinson]

, you'll have a gradient down the store

I think you'll be surprised at how little there is... mine is a fairly even temperature all the way down to within say, 30 litres of stored water above the stat. Then there is a sharp fall.

 

[SimonH2]

I did say "It does depend on whether you have a thermal store (internal coil) or heat bank (external PHE) ..."

For a thermal store there is a very pronounced gradient down the store. The DHW coil starts absorbing heat right at the bottom of the store, and heat is exchanged progressively as the DHW flows up through the coil. So there's a distinct difference in temperature between store top and where the CH tapping is.

It's a different matter for a heat bank. There it's "all or nothing" - you draw off hot water from the top, pass it through the PHE, and put it back in at the bottom. If primary flow rate and DHW flow rate are well matched, then the return will be quite cold, but under normal flow conditions (DHW flow rate is less than max) then you can have quite warm water returning to the bottom of the store*.
That's why I'd expect to see what you observe. There'll be a quantity of fully hot water at the top that's been loaded by the boiler, and then probably a fairly sharp transition somewhere around the thermostat. The boundary will move up and down with use (boiler running = boundary moves down, DHW or CH running = boundary moves up).

* I have figured out a way of avoiding this (and putting very cold water back in at the bottom of the store). It's not what you might call trivially simple - but barely more complicated than a combi boiler.

 

[BertCoombes]

* I have figured out a way of avoiding this (and putting very cold water back in at the bottom of the store). It's not what you might call trivially simple - but barely more complicated than a combi boiler.

Gledhill did this by modulating the DHW pump eliminating a DHW TMV valve. Gledhill used an off the shelf Czech pcb, designing their store around the functions of the available pcb. The same pcb is used by some European thermal store makers. The pcb also has integrated boiler anti-cycle control using one store cylinder temperature sensor. It will automatically hold off the CH pump while the thermal store reheats, so no slugs of cold water around the rads.

These pcb's are freely available from Gledhill parts suppliers as are the temperature sensors. If you are into making your own thermal store then using one of these pcbs can save a lot of hassle. Obtaining the Gledhill instructions (downloadable?) and understanding how it works (the functions of the pcb) would be the first step. The DHW pump has to be one of the special Grundfos modulating pumps. The Czech pcb simplifies the mechanical and electrical arrangements.

Glad to help. Off to work.