Thermal stores - makes?

What do you mean by: "(which are more common than the external control modulating)."? Are you on about the DHW side?

An Alpha pump can be on the CH loop with TRVs all around and no wall stat. Simple and easy.

Reply to
Doctor Drivel
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Doctor Drivel coughed up some electrons that declared:

Yes. The Gledhill Boilermate OV (and OV SOL) used a Grundfos UPR 3 wire pump, which is externally speed controllable (don't know if it's was an analogue voltage or PWM control - can't find any datasheets)

There was a temp sensor on the HW outlet pipe of the plate exchanger and a computer in between that formed a control loop. DHW not warm enough => make pump on primary side go faster.

The hydraulics of the control loop (the water) are essentially the same as the ZED system, only ZED uses a mechanical means to restrict primary flow to the plate with its temp sensor on the DHW output. I'm suggesting that if you restrict the flow mechanically, it would be a good idea to use a self modulating pump (which are more common than the 3 wire kind) so the pump isn't beating its brains out when a small flow is called for.

Either seem better than a mixer that ends up with full flow round the primary whether it's needed or not.

Yeah I was going to do that.

At least, if DPS don't want to build me a bank with the aforementioned bits, they will allow me to buy a bank with bits missing so I can DIY the appropriate valves and pumps myself. I like DPS in that respect - and there's none of this "we don't like talking to the end user" bollocks, which I did get from Gledhill until I was on the point of yelling at them. I think Gledhill's attitude didn't do them any favours and I've other similar complaints on various forums.

Cheers

Tim

Reply to
Tim S

As I said, a 3-port diverter RAVK can do the job with a simple cheap pump - the other port just lops back to the suction side of the pump with an adjusting valve. Or have a 2-port and a pressure balancing valve after the pump which again loop back on the other side of the pump - may be cheaper.

Having a Smart pump and a RAVK may mean that one control will fight the other. I have not rigged that sort up yet and tested for stability. It may be the answer, but on the surface poses potential problems.

Gledhill at one time would not supply individual units, only a minimum of around 5 of them. They only dealt with the new-build sector - the one which went under. As time went on they relaxed their view.

They had the right idea, having it all easily installed in one case. It looks neat and the insulation value is phenomenal. DPS and others should take note.

They never kept up, right with the times - a difficult thing I know. New boilers like the Broag, and others, with more advanced control systems, like integral weather compensation, etc, would make some stores sing. Although Gledhill would put in a Smart pump for you on the CH loop, which saved installation costs of a room stat. They never took advantage of new controls on system/heating boilers. I described the Avantplus 18V connected to a store and real cheap for what the whole system offers.

Gledhill found it difficult offering small improvements, at a little extra cost, as builders could not see the advantages. Weather compensation? Most haven't a clue what it is or what it offers. I have seen some boiler with integral weather compensation and no outside senor fitted. They fit just on-off room stats. A total waste of a control system because of ignorant drains centric plumbers. Weather compensation is a good selling point for homes - the weather lowers and raises the rad temps. And saves money - selling point too.

Gledhill also never offered stainless stores. I would only go stainless these days as they are now cost effective. And they last and last. Advanced Appliances a make custom to order.

Gledhill also do not offer pressurised stores. No G3 required and only a pressure relief valve needed on the store - also one on the boiler. Only charged to 1 bar. Best have a temperature high limit with them in case.

If Gledhill, or others, offered:

a) a cased pressurised heat bank b) integral expssionn vessel c) integral boiler, d) weather compensation e) TRVs all around option f) integral Magnaclean type of filter g) Easy to fit h) Direct boiler and rad circuits

Then it would be No. 1. on SEBUK in efficiency, as the condensing boiler would rarely would not be condensing with very low temperatures. The boiler would not cycle and always on full flow through the boiler, which means it would last and last as controls are not being over activated. The same with the pumps - no restrictions on flow meaning an easy long life.

ACV Heatmaster, go some way to offering that, but G3 is required and some external pumps, etc. The Heatmaster is around £3K, but still worth it for a 2 bathroom one-box solution, as all is in one case.

Reply to
Doctor Drivel

Doctor Drivel coughed up some electrons that declared:

Ah, I get it.

Yes - that looks like a solution too.

Cheers

Tim

Reply to
Tim S

It's a fun place to try to find. Behind a row of shops.

We've got a GX heatbank which is intended to accumulate hot water from solar, log burner and an LPG boiler. However due to a bone-idle builder I can't yet give a performance report.

Reply to
Steve Firth

Tim, I know it's a while off yet but when you do get your system up and running (and have had time to see how well it works) perhaps you'd report back here to us on it (maybe with some photos)? It would be a good addition to the wiki article which IIRC merely speculated on this sort of approach.

Reply to
YAPH

This man DIYed a solar heat bank to great success:

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was guided through. His comments on its performance is worth noting.

Reply to
Doctor Drivel

Doctor Drivel coughed up some electrons that declared:

Most interesting - thanks - I'm printing it out to read again later.

May Santa bring you 27 mince pies and new batteries for your Prius.

Happy Xmas!

Cheers

Tim

PS

I had started to wonder about regulating the return temp[1] on the primary side of the plate exchanger for the DHW. It's not like we need totally precise DHW temp regulation, plate exchangers apparantly get the output water up to the virtually the temperature of the primary side and anything that reduced the primary flow back to the store when it's not needed will benefit stratification.

[1] Might be easier to arrange

Cheers

Tim

Reply to
Tim S

Sure thing - behappy too

Cheers

Tim

Reply to
Tim Southerwood

There are photos there too. He had to fit an accumulator which is not applicable to you. There are far too many elbows for my liking in the installation, but does show a finished system. He fitted a needless by-pass on an Alpha pump, which needs to be taken out, which he realised after taking temperatures. He never fitted a simple pipe spreader either which would enhance stratification, but the condensing performance is still startling. As the figures indicate a large kW plate heat exchanger pays dividends, and not that much more expensive either.

The batteries are in great nick and fab. I don't like minced pies.

The RAVK sensing on one side on the plate and operating on the other is the best way.

Reply to
Doctor Drivel

Doctor Drivel coughed up some electrons that declared:

Having printed it out, and read it at friends' this morning over coffee (by "morning" I mean 11am) I was very impressed.

It's cemented the bits I was fairly certain about, added some interesting stuff and clarified that I shouldn't be buying a very expensive lump of copper from DPS (as fine folks as they are) - I should be buying a long thin copper cylinder from a cheaper copper bashers and having them put in a load more 22mm and immersion bosses where I want.

Let's face it - it's hardly going to take much more time to put together with standard pumps, flowswitches and mixers, I can put a few extra tappings in where I'm not sure of the optimum height and replumb later if it turns out I made a mistake.

What I'd like to do is set up a simple electro-mechanical control system that works (ie what DPS do), then later pepper it with sensors and a small AVR cpu board of my design to measure everything. It should then become clear if further optimisation and/or computer control is likely to be beneficial - and if it is, I'll retain the electro-mechanical controls as a failsafe (well, bloody computers always go wrong, don't they...)

How about mincing pies then?

But what's the time constant of the feedback loop likely to be - I feel it may be too slow?...

Cheers

Tim

Reply to
Tim S

That is what I told you.

Yep. I guy I know, I taught him about assembling heat banks, assembles them in his garage. Takes a hour or so. He used them in place of unvented cylinder. He orders a combination cylinder from a local copper basher with the tappings where he wants. He makes a fair amount and still undercuts an unvented cylinder installation.

He does not try to sell the CH part as he finds the customers do not understand the CH buffer benefits, so sells it as mains pressure DHW, just replacing a DHW cylinder. When a comprehensive installation he does an integrated CH/DHW heat bank using a Smart pump and no room stat and TRVs all around.

Gledhill use a microprocessor to modulate the DHW pump and monitor the store. Their pcbs are available, and if they do what you want use one of those.

They are fast enough and not too fast. They are used in District heating sub stations. Oventrop also make them - maybe cheaper.

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to products, 3-way valves.

Reply to
Doctor Drivel

Watch youdont put money up front gleddhill is gone down thetubes,they are like mfi& wollies they are bust

cheaper.http://www.oventrop.co.uk/en/index.htm>> Go to products, 3-way valves.

Reply to
badbadwolf_uk

Yes?

Reply to
Doctor Drivel

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