Thermal stores and solar

I agree with you for once, that man, (you) is certifiably insane.

Reply to
Steve Firth
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You haven't a clue what you are on about. I tried to make you understand once but were not bright enough. Having a Chav attitude did not help either.

You are talking through your arse!!!

I hope he does and ignores know-it-all amatures like you.

I gave you enough the first time.

Another point you know sweet FA about... The great thing about a thermal stores is that you CANNOT oversize the boiler. It will fire until the store is up to setpoint then cut out - as long as the flow and return pipes are sized to suit and can take the boiler's output. An oversized boiler will just reheat the store quicker, that is all. A boiler connected directly to the rads on part load is very inefficient. And then the auto by-pass valve opens creating a direct short cut reducing condensing efficiency greatly.

Also, a thermal store can have a smaller boiler attached. The boiler can be downsized by approx 20%.

If a rad system holds 150 litres of hot water, then a store with 250 litres of hot water ready in the morning will dump it heat into the rads and heat the rads within minutes with heat in reserve to spare. Once the house is up to temp the boiler reheats the store for the next call of heat to be injected into the heating system. Boilers on stores are sized for "average " use not "peak" use, as when directly on rads.

The stores acts as wonderful buffer evening out heating demand and heat input. It decouples the heat demand from the heat generator (boiler) The boiler always runs at optimum efficiency with always full water flow through the boiler irrespective of heating demand in the house. It reheats with one long efficient burn. It does not inefficiently cycle as boilers directly on rads do. Cycling reduces the longevity of boilers. Many system have the boiler only cut in to reheat the store only twice a day.

If you get a good deal on an oversized boiler go for it and fit it to store. An oversized boiler rad system can create inefficency. In short if you do the calcs on a rad only system and it comes out at say 25kW, anything from

20kW upwards is fine as long as the store has enough capacity. You may get a good deal on say 28kW - thjen just go for it.

Few understand the operation and advantages of stores. And you clearly do not.

No !!!! A competent man. A competent DIYer can fit his own boiler by law. A DIYer CANNOT fit an unvented cylinder or do the annual service - by law.

No approved man is needed to fit a vented store. A DIYer can do it.

Which costs. Not all GasSafe service men are unvented trained. Unvented cylinders can take down the side of your house when they explode.

Yes, and it extensive. Every valve has to be checked. That means over-heating the cylinder to see if all high limits work. That takes time and cost.

You are an idiot. DO NOT GIVE ADVICE on matters you know little of.

Reply to
Doctor Drivel

I can't speak garbled Essex.

You do not need link sunshine. Just read what I write. You would not understand a link anyhow.

Reply to
Doctor Drivel

You are still a lunatic.

Reply to
Doctor Drivel

I think he meant to say that he shops in poundland

Reply to
geoff

I agree with you again.

Reply to
Steve Firth

Maxie that battery link said Poundland sold the best battery. Great for all your "toys".

No Poundlands near me though.

Reply to
Doctor Drivel

Well well, I asked a question in all innocence and seem to have stirred up a cauldron of almost religious fervour!

It seems to me that the main conclusion (as with most things) is along the lines of 'it depends'.

Of course there's great value in insulation and draught proofing, although there's a limit to how much of that can be done on a Victorian house, especially in a conservation area. Ultimately though, that's a completely separate issue.

I have no doubt that PV panels are a wonderful thing but I'm personally disinclined to get involved there and I suspect that the economics are not as good as some advocates would claim, especially over the long term when the government withdraws subsidies.

Solar thermal, on the other hand, is DIY-able (as a quick web search easily shows) and should be able to make a contribution when designed and implemented well. It may even show a financial return one day, though I wouldn't hold my breath. My main interest is in 'having a go' just to see if I can make something that works and I was wondering how a successful outcome could be interfaced most usefully to whatever I fit for DHW /heating, given that I need to change aspects of that anyway.

If unvented cylinders are much cheaper than thermal stores (even here pricing seems a little obscure without defining a tight specification), then it would be difficult to justify a major price difference just to play with the system. Although I think they have their problems, these are more administrative than technical and they have been around for a long time so shouldn't be dismissed. They are also available with solar coils, for relatively small extra cost, just like thermal stores, so there's potential there.

Nonetheless, whichever I choose in the end, it will liberate a perfectly serviceable insulated DHW tank, which I may be able to re-use to play with solar heat in the conservatory, where trapping some of the daytime heat to reuse after dark would be a great improvement for spring and autumn (and most of summer if the current trend continues).

My thanks to those who have made constructive comments and brought new perspectives, which is what we come here for. Certainly my thoughts have evolved in a short few days, though there is a way to go (!)

I don't really understand why people get so polarised on these topics: Every situation has its own optimal solution, which may not be appropriate in another circumstance. Even the best solutions will involve compromises and the trick is to select the most appropriate outcome taking all aspects into account. Making that selection depends on gathering authoritative information, which is best found from objective and impartial sources.

I'm not convinced that dogmatic adherence to any given mantra ever has a place but especially here: It's only heating, not life and death!

Reply to
GMM

Because massive amounts of miney are ebing pouyred into marekting to make you believe...this ir that.

The people who are doing te conmning, or have been conned hae deep interests in their convictions.

The skeptics are alarmed at the total waste of money - and in the end its their money that is being wasted - on technologies that don't work. My father in law spend a lot of his life savings on solar panels which he was assured would 'have his heating bills' The fine print made it clear that this referred only to his hot water bills.

He assured me 'the man said it would halve my heating bills'

three year on, they have actually cost him money to get the shit cleaned off them caused by building works next door. At the most they would have saved him 150 quid a year mostly in summer when there isn't that much need for hot water anyway.

To some companies, it *is* life and death. Its also life and death to pensioners who have to face rising heating bills caused by market bending to accomodate all this eco-bollocks.

Reply to
The Natural Philosopher

Link?

Stop willy waving, and come up with some numbers.

You are demonstrating that you have failed to grasp a number of the advances of the last few decades.

Firstly explain why you think part load load is "very inefficient"?

There was a time that part load meant lots of boiler cycling.

There was a time boiler cycling would waste energy.

Neither are particularly true these days.

And that saves what exactly? £50 off the purchase price?

Again, what are you trying to achieve? The lions share of the house warm up time will be the thermal mass of the house and its air content. The fact that you can get the rads up to temperature 5 minutes sooner is neither here nor there, and with an optimising prog stat of no relevance whatsoever.

Yes, but again, so what?

Indeed it does. An returns what exactly?

Significant saving in money, or improvement in comfort - no.

Unless you have a particular problem to solve such as the aggregation of multiple heat sources, or very limited peak input power, what is the point?

More importantly, what is the cost?

Which is exactly what modern boilers do anyway even without the store. If you can get a seasonally adjusted efficiency of over 90% (and remember this is an efficiency figure that includes all the "non optimal" running on part load that you seek to eliminate) what more do you expect to gain?

Boilers don't cycle inefficiently now anyway. With low water content HEs, and pump overrun, the residual heat in the HE does not just waft out of the flue - it is distributed in the house.

You seem to be trying to solve the problem of wasted heat caused by the use of very crude system controls, cast iron lump boilers with a couple of gallons of water in them, and a pump that went off with the stat demand. The world has moved on.

Whoopy do.

So let me get this straight... say I find somewhere doing a boiler for £100 less, I can take full advantage of that simply by lobbing a grand or more at a thermal store?

What school of economics did you study in?

You see here is where an engineer will differ from someone such as yourself. Rather than be driven by quasi religious dogma, and engineer should look at the actual requirements, and work out a cost effective way of meeting those requirements.

There are some occasions where a store makes good sense, however there are plenty more where it does not. Hence there is no sense in applying your "one size fits all" logic to every situation.

Citation?

It still comes under building control.

A DIYer can fit an unvented cylinder. Its less complicated than fitting a combi.

Just as well they are designed not to explode then.

(is this where you find a youtube video of someone demonstrating what happens if you intentionally defeat the multiple redundant safeguards and then heat it electrically until it goes bang? I could probably find one of someone crashing a car into tree for you if you like?)

I will take that as a no them.

Actually I am not "giving advice", however I think it is fair to highlight the many flaws in your reasoning as a public service when you start spouting the same old script with your traditional messianic zeal

Reply to
John Rumm

You can certainly speak garbled something... try again.

Link?

Reply to
John Rumm

We agree. You are insane.

Reply to
Steve Firth

Because massive amounts of miney are ebing pouyred into marekting to make you believe...this ir that.

The people who are doing te conmning, or have been conned hae deep interests in their convictions.

The skeptics are alarmed at the total waste of money - and in the end its their money that is being wasted - on technologies that don't work. My father in law spend a lot of his life savings on solar panels which he was assured would 'have his heating bills' The fine print made it clear that this referred only to his hot water bills.

He assured me 'the man said it would halve my heating bills'

three year on, they have actually cost him money to get the shit cleaned off them caused by building works next dpopr. At teh most tey hwould have saved him 150 quid a year imostly in summer when there isnt that much need for howt water anyway.

Reply to
The Natural Philosopher

Its dribble, what did you expect. Just be glad you did not ask about combi boilers ;-)

Very much so.

Indeed. Alas this one of the things that the passive house champions like to gloss over - achieving the required levels of insulation in existing buildings is far more challenging than building them that way in the first place, or retrofitting when you don't have the option of partly demolishing and rebuilding great sections of it, or need to do something that is in keeping with semi-detached or terraced neighbours.

For the best subsidies you have probably missed the boat. In theory the subsidy is guaranteed once you are signed up for one, although that remains to be proven in practice.

If you can build the system from (near enough) scrap, then a return ought to be possible in time.

Yup, why not.

I was originally planning a heat bank type solution for DHW since we are fortunate enough to have the airing cupboard space for it, and a decent mains cold water flow rate. The off the shelf solutions like the pandora were silly money, so I looked at a DIY heatbank with external pump + PHE for heating water on demand. The main problem there seemed to be the moment you want a 250L cylinder to build it round the prices of those are quite significant before you add on the extras. The logic that PHEs are cheap only seems to hold as far as the relatively low output ones. By the time you look at 100kW units and above that can deal with the flow rate we have available, then they start getting quite pricey as well.

Then there was the issue of integrating it all into a system with a decent boiler, a control system that allowed multiple heating zones, split temperature operation, and weather compensation. At which point the ease of buying all the bits from one maker who has designed them to play together in that way, became more attractive.

Your requirements and circumstances may well be different however.

Yup, curious isn't it?

Indeed, and optimal needs to include price, complexity, maintainability etc as well as just raw performance.

Good luck with that one ;-)

Reply to
John Rumm

Wait till someone goes round and adds £00 quid a year council tax to every home with solar on it, on the basis that if you could afford them you were an antisocial rich thieving FIT gobbling toffee nosed bastard who deserves all he gets.

I mena,. petrol duty goes up, so you use the car less. Guvmint sez 'oi! cant have that, we will tax the CAR instead'. Up goes road tax.

If two or three days work is worth £100 a year to you, yes.

Reply to
The Natural Philosopher

The witless idiot changes what I wrote. Sad isn't it! He needs locking up.

Reply to
Doctor Drivel

Reply to
Doctor Drivel
[snip drivels pointless repost of John's post]

Was there some reason you did this without snipping or adding your own "content"? A rrason that doesn't show you up as a lunatic, I should add.

Reply to
Tim Streater

I do not have to justify myself to a know-it-all amateur like you. Just read what I write.

Again, know-it-all, you haven't clue about heating or thermal storage.

BTW, total and utter nonsense. You haven't a clue.

Total tripe! The heat in the thermal store is immediate dumped within a few minutes into the rad circuit, taking the house up to tamp quite quickly. That is the lions share of the house warm.

BTW, the point was smaller boiler that uses the thermals store as highly useful buffer.

5 minutes my arse! See how long a boiler heats all the rads to full temp from cold in mid winter. A store does that in a few minutes.

What is so what is that you haven't a clue - but think you do.

Oh f*ck me. What a know-it-all dork!

Yes. IT DOES BOTH know-it-all.

Any extra cost is negligible for the "massive" benefits.

They do hell !!!! That is why new boilers have a short life span. A cheap boiler on a store that does not cycle, operating the optimum temperature with full flow lasts and lasts. Put the same boiler on a direct rad system, with TRVs and an auto-by pass and the efficiency drops off with the boiler needs replacing after 5 to 7 years. They also sludge up inside the heat exchanger. sludge from the rads gets baked on the inside reducing efficiency greatly.

Those sedbuk figures on a perfectly balanced system in lab conditions, which do not take into account the damage being done to the boiler and the short life it will have.

TOTAL BOLLOCKS!!!!

Know-it-all, you really don't know !!

A grand. You never looked around !!! Take into account the cost of replacing the boiler because of short life, and the breakdowns as well.

A uni one.

< snip opinionated drivel from a know-it-all >

The only reason I respond to the likes of you is so others do not take you seriously. You do actually think you know what you are on about.

Reply to
Doctor Drivel

This man is mad.

Reply to
Doctor Drivel

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