Megaflo or something else

[heatingman]

Mr extendingsoon, I am not going to get involved in a slanging match with Dr D, he is entitled to his opinion.
My concern is you make what I believe to be an incorrect and potentionally expensive mistake by selecting a Thermal Store.

Dont get misled by sales/technical jargon. Nothing supplies instant hot water. Everything has to heat up plus flow to tap.
A stored water system will supply a given amount of water.
A combi will supply constant hot water at a flow rate.
Non of the above are instant.

Now for the Blue Peter part.

Get a very large drum/tank and fill it with boiling water.
Get a garden hose, connect one end to outside tap, drop as much of the coil into the tank of hot water. Turn on the tap and adjust the flow to get a decent temp rise. The water in tank will start dropping so keep chucking heat into it.
You have now built a very basic thermal store.
The hotter the tank, the more heat can be scrubbed into coils. The more coils/longer your hose the better heat transfer but flow rate will be even greater reduced.
Hopefully in laymans term that explains the 35 deg C temp rise principle with a limited flow rate.

Cant wait for response's to this one.

 

[Extendingsoon]

Appreciate the response. I'm not trying to start a slanging match. As you say each to their own opinion - then I will need to decide which opinions I give more weight to and what is important for my situation.

thanks

 

[Doctor Drivel]

Mr extendingsoon, I am not going to get involved in a slanging match with Dr D, he is entitled to his opinion.

It is NOT an opinion. It objective engineering assessment.

My concern is you make what I believe to be an incorrect and potentionally expensive mistake by selecting a Thermal Store.

But you clearly haven't a clue about them.

Dont get misled by sales/technical jargon. Nothing supplies instant hot water. Everything has to heat up plus flow to tap.
A stored water system will supply a given amount of water.
A combi will supply constant hot water at a flow rate.
Non of the above are instant.

You clearly haven't a clue!!! Once heated a heat bank delivers instant hot water in that the cold water from the street is heated instantly and has not hung around in a tank and/or cylinder before and after being heated. Got it?

A heat bank or any cylinder can have a secondary circulation pump/loop that give instant DHW at the taps - no wait whatsoever. A combi gives "infinitely continuous" DHW. A "directly" heated bank can do the same. When the heat store runs out the DHW delivery resorts to what the boiler outputs is. If it is around 28kW then it delivers around 12-13 litres/min. The same principle in the Alpha CD50 combi - two stage flowrate and never run out of DHW.

Now for the Blue Peter part.

Get a very large drum/tank and fill it with boiling water.
Get a garden hose, connect one end to outside tap, drop as much of the coil into the tank of hot water. Turn on the tap and adjust the flow to get a decent temp rise. The water in tank will start dropping so keep chucking heat into it.
You have now built a very basic thermal store.

Fabulous! Good thinking Batman!!

Cant wait for response's to this one.

No response. You have indicated you know how a basic thermals store works. Now look into plate heat exchangers and and the super efficiency heat transfer of these units.

Understand plate heat exchangers and how then can be used. Like fitting a large "direct" cylinder heated by a plate heat exchanger and bronze pump. Heated super fast, can resort to only what the boiler outputs and is cheaper too to install as quick recovery coiled cylinders cost.

The small plate heat exchanger is the greatest innovation in domestic heating for the past 30 years. They are cheap.

 

[Doctor Drivel]

Appreciate the response. I'm not trying to start a slanging match. As you say each to their own opinion - then I will need to decide which opinions I give more weight to and what is important for my situation.

thanks

Do not go on "opinion".

 

[Softus]

It is NOT an opinion. It objective engineering assessment.

That's merely your opinion.

 

[Extendingsoon]

I agree with you Softus, but he does have one. Scanning back through the pages I see plenty of sarcastic comments and not one piece of advise, opinion or fact from you.

I challenge you sir.... stand up to the plate and deliver your system proposal!

 

[Softus]

I agree with you Softus, but he does have one. Scanning back through the pages I see plenty of sarcastic comments and not one piece of advise, opinion or fact from you.

That's a fair and reasonable observation, although I doubt that you're using the normal definition of sarcasm. (And I notice that you were fairly disparaging on page 2).

I know that poking fun at spelling mistakes (e.g. scaled to death) is a cheap shot, but for every occasion that DD labels all professionals as "thick", or "rip-off" merchants, simply because they disagree with him, I think some gentle ribbing is equitable restitution.

Notwithstanding that, and whilst I regret the fact that some of the bickering has bled into your attempt to find a solution to your problem, I'm also concerned about the bigger picture regarding the member who currently calls himself "Doctor Drivel".

It wasn't my intent that you be dragged into a mild fued, but fueds tend to follow and envelop DD like Linus' dust cloud.

You're probably not aware that he caused mayhem in his previous incarnation, as "Water Systems", and that he hates any plumber, or heating engineer, or RGI, who isn't retired and who doesn't spend all their time 'researching' German heating systems and European regulations and standards. He's incapable of taking part in a calm and rational debate, because his mind is closed to the possibility of being even the tiniest bit wrong. For this reason alone you should treat his "opinion" with the utmost caution. And, of course, mine too.

If you read a supposedly technical assessment that includes such words as "super", "instant", and a sprinkling of various superlative terms, then you should know that these are all relative terms that completely lack determinism. An objective assessment/comparison of heat banks and unvented systems is possible, but I don't have the figures to present one to you. If I could, I would, but I doubt that many people do, and at least I'm not pretending that I know that one is better than the other in all circumstances.

Plate heat exchangers have their pros and cons. An internal coil is easier to descale, but harder to replace, (i.e. not an economically viable option). When a plate HEX scales up, which it will, especially at the high primary temperatures that a certain person is advocating, then you can quickly and easily bolt on a new one. I've replaced four in the last three weeks, and the quickest one took about 45 minutes to get the point of refilling.

So, the overwhelming advantage of a thermal store, IMHO, is that you can install one and maintain it yourself.

The obsession with removing water storage cisterns from the loft space is merely that - an obsession. They are also very simple for amateurs to maintain. Vented systems have served this country well, for many decades, and they continue to do so. With an unmatched record for water quality, this country has remarkably few interruptions to its water delivery, but you're as capable as anyone of predicting what effect the weather will have on households who rely on the mains supply for all their washing and drinking needs.

On the other hand, a working Megaflo represents a lot of engineering and careful manufacture, and, predominantly, skilled installation. This idea that charging for service and maintenance equates to profiteering smacks more more (to me) of envy than of an detached and objective assessment of running costs.

The fact that the debate is heated (phnarr) supports my view that there's no simple answer - only a fool would pretend otherwise. And there's no fool like an old fool.

 

[Doctor Drivel]

...

<snip total drivel>

He wants waters systems that scald kids to death or explode and take down the side of the house.

He made all that up. Wow!!!

 

[Softus]

That's right - I've been rumbled. I've been caught out by Drivel's eloquence and visionary analysis. In fact, I just fabricate everything I write. None of it is based in reality.

I also have a lifelong ambition to see all cildren scaled to daeth by unvented systems, or, if no childern are nearby, for a minimum of one wall per house to be destroyed in an expensive explosion witnessed by a specialist commercial lawyer, and for Heatrae (sic.) Sadia to be liquidated by the ensuing class action suit.


_______________

Now that's what you call sarcasm.

 

[Doctor Drivel]

That's right - I've been rumbled. I've been caught out by Drivel's eloquence and visionary analysis. In fact, I just fabricate everything I write. None of it is based in reality.

This what I like, self-awareness. You know you have a problem.

I also have a lifelong ambition to see all cildren scaled to daeth

You are sick!! You professional need help.

 

[Doctor Drivel]

That's right - I've been rumbled. I've been caught out by Drivel's eloquence and visionary analysis. In fact, I just fabricate everything I write. None of it is based in reality.

This what I like, self-awareness. You know you have a problem.

I also have a lifelong ambition to see all cildren scaled to daeth

You are sick!! You need professional need help.

 

[ChrisR]

Don't get hung up on the nonsense about unvented cylinders exploding. Your gas boiler is much more dangerous. It can explode for much the same reasons. A few do, because they don't have as many safety devices. They can also set fire to you, leak gas at you or poison you.

Thermal stores/heat banks can also kill you

Drivel is paranoic about all sorts of things, and is going out of his way to give you a one sided picture. He complains that unvented cyllinders lose heat, but forgets about heat stores doing the same.
He forgets to mention that a thermal store requires a boiler to operate less efficiently when supplying hot water than an unvented system does, because it requires the boiler to run at a higher temperature.
If he were an engineer he'd set out the analysis of all those things. He doesn't because he needs therapy.

Thermal stores give their owners a great deal of trouble. About 3/4 of the owners, I would say, wish they didn't have them. Drivel would say they're misguided, stupid or whatever - you decide.

You can buy a 200 llitre unvented cylinder for under £500. Compare :
http://www.gasapplianceguide.co.uk/boilermate_a-class_ov_technical.htm

I wish the moderators would hit the SPAM button on Drivel.

 

[Extendingsoon]

Well thanks you one and all. It's all been very informative and I've certainly learned a lot about heating systems over these last few days. Whether I can actually explain it all to anyone else is another matter.

I think I have enough information to be going on with for now, but I may be back at some stage for further advice once I've made a decision.

As for now good luck to you all - and your chosen systems - and given the date today I think you should all have a little love in your heart and messages to your fellow tradesmen/engineers.

Thanks guys

 

[Doctor Drivel]

Don't get hung up on the nonsense about unvented cylinders exploding. Your gas boiler is much more dangerous.

So lets have two bombs in the house. Two wrongs make a right eh. Duh!!!!

Thermal stores/heat banks can also kill you

A vented one will not. Unlike an unvented cylinder It is "failsafe".

Drivel is paranoic about all sorts of things, and is going out of his way to give you a one sided picture.

Recently a child was scalded to death it its bed as scalding water poured from collapsing cold water tank in the loft. Like pouring buckets of boiling water over the child!!!! Many predicted such an event. The knobheads said "oh no that can't happen!" Of course it did. Then afterwards they said " there are millions like that and only one died. So one kid having boiling water poured him is OK then in their tiny minds and business as usual and look forward to the expensive holiday from the money they make installing potential death traps.

He complains that unvented cyllinders lose heat, but forgets about heat stores doing the same.

They do that too. But heat stores are insulated to higher standards. The average airing cupboard is warm. Put a Gledhill in there and not warm at all.

He forgets to mention that a thermal store requires a boiler to operate less efficiently when supplying hot water than an unvented system does, because it requires the boiler to run at a higher temperature.

It does? Firstly a thermal store uses an internal DHW coil, a heat bank a highly efficient plate heat exchanger. A heat bank can run at 60 to 65C and provide DHW.

A boiler heating a heat bank directly is in an ideal hydraulic environment. This promotes high efficiency and boiler longevity. Use blending valve on the flow and return and it ensures the ideal delta T on the boiler. Also full flow through the boiler at all time. A condenser at 22C delta T supplying a heat bank at 70C will have return water at 48C - brilliant for a condensing boiler promoting high efficiency. Efficiency rises as the boiler heats the store in one long efficient burn.Simple more reliable boilers can be used.

Put an outside weather compensator on the heat banks CH section and very low return temperatures indeed and super high efficiency.

If he were an engineer he'd set out the analysis of all those things.

If you have an inkling of engineering nouse you would say "thanks Doctor Drivel, I never knew all that, I'll use them now instead of killing kids in the future".

Thermal stores give their owners a great deal of trouble. About 3/4 of the owners, I would say, wish they didn't have them.

Do they? In your tiny world they do.

You can buy a 200 llitre unvented cylinder for under £500. Compare :
http://www.gasapplianceguide.co.uk/boilermate_a-class_ov_technical.htm

Yes a cheap and nasty one. The Boilermate also does CH as well which that unvented cylinder does not. A Boiermate is an "integrated" heat bank - that is, it does CH and DHW. Unvented cylinders just store DHW very dangerously and require an annual service charge for the displeasure of having one. Nice little earner for you eh!

It is like talking to the wall with these numpties!!!! Few of them have any engineering analytical skills of any description. A bunch of arm wavers.

 

[Doctor Drivel]

I think you should all have a little love in your heart and messages to your fellow tradesmen/engineers.

I am the most lovable person in the world.