The water coming out of the taps is heated instantly from cold to hot - electric thermal store, instantaneous gas/oil water heaters, electric shower, etc. It is not heated then stored for later use, as in say an: unvented cylinder, undersink storage heater, etc. Very simple.
Economy 7
- Thread starter hard-work
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Probably not - but, as I've said, I see a very big difference between 'instantly available' hot water (which can be almost the case with 'stored hot water' under the sink, or even in a nearby DHW cylinder, as well as in systems which have constantly-circulating hot water {as in hotels etc}) and "instantaneous" ('real time', 'on demand') water heating (as in combis and electric showers etc.).
That's what I would have expected, but it seems to be a case of "everyone other than hard-work" (I wonder how he got that name?!), who wrote ...
... which is what started all the discussion I've been having.
Kind Regards, John
Have you done it again?
So, what is the difference between these instantaneous heaters and "heated instantly from cold to hot"?
Where is the 'store' - thermal or not?
Agreed.
So, what is the difference between these instantaneous heaters and "heated instantly from cold to hot"?
Thermal stores store water. They also store sludge.
End of line.
End of line.
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I think it would be thermal rather than not. Stored heat in a solid or liquid heat transfer medium is transferred to cold water to heat it instantly.
Do you have an example of such a thing?
I have just read this thread. What I took from @hard-work's first post on this (#77) was that he was talking about a very well insulated tank of material that had been previously heated by electricity and stored that heat, and when hot water is needed, fresh cold water passes through a heat exchanger and takes heat from that store. His latest post (#110) seems to confirm that.
Such a system seems, to me at least, possible but not that practical. To heat water (which has a very high heat specific capacity) rapidly then the store needs a huge heat capacity or the flow of cold water needs to be low (or a combination of the two). After all, to achieve the same effect electric showers have to have a power rating of c. 9kW. Also the temperature of the newly heated water will be less than the temperature of the material in the store.
And I was just about to ask if such a device existed for a domestic setting when I saw that @EFLImpudence had just asked the same question.
BTW, I don't think that hard_work explained this very clearly and I well understand why @JohnW2 did not understand what was being talked about.
Such a system seems, to me at least, possible but not that practical. To heat water (which has a very high heat specific capacity) rapidly then the store needs a huge heat capacity or the flow of cold water needs to be low (or a combination of the two). After all, to achieve the same effect electric showers have to have a power rating of c. 9kW. Also the temperature of the newly heated water will be less than the temperature of the material in the store.
And I was just about to ask if such a device existed for a domestic setting when I saw that @EFLImpudence had just asked the same question.
BTW, I don't think that hard_work explained this very clearly and I well understand why @JohnW2 did not understand what was being talked about.
Indeed, but as EFLI has questioned, does such an animal actually exist - and, if do, why? If one wants to use hot water that has been (ultimately) heated by some prior heating, is it not going to be inevitably more efficient to initially heat the water (and then store it in a well-insulated store) than to heat something else (maybe even 'other water') and then use that to heat cold water when hot hot water is needed?
Thanks for understanding my problem
If what hard-work is talking about is as you suggest, and if such a device does exist (and, I agree with you, it's not impossible, even if not very sensible), then, if anyone uses it, I suspect that they have probably been taken in by nonsensical marketing hype of some sort.
Kind Regards, John
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Second quote was Stephen's.
So was the first one (despite what it says)! That's the second time this has happened to me today - what's going on?Second quote was Stephen's.
Anyway, I'll correct it.
Kind Regards, John
They exist and are for sale. They can also do wet heatings systems as well by taking the flow and return off the mid to bottom section.
How they work.
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You don't appear to provide provide a link - so perhaps you can you tell us ... does that use electricity to heat something (maybe water) and then later use that 'heated something' to heat cold water? If so, what is the point of that 2-stage process?
Kind Regards, John
Yes, the stored water (hence thermal store) is heated and then usually high pressure cold mains water is run through an internal coil and instantly heated. The stored water (the heat medium) is static and can be low pressure, then no problems with explosions and the complexity of high pressure stored water. They tend to have a blending valve on the DHW outlet which mixes with cold to give the set temperature. They are very simple indeed. Some do not need overflow or discharge pipes to outside, so they are ideal for fitting way inside premises.
Connect the cold water in (at the bottom of the copper pipe) the hot water out (at the side of the chrome valve) and the overflow pipe. Then wire it up. Low pressure store of the heated water transfer medium and high pressure hot water. Simple. Instant high pressure hot water. A DIY job too if you have the skills.
No, it makes pretty well no difference long term. it is a common misconception that if you have a tank with (say) 100l of hot water, and draw off (say) 20l of it, then it takes the same energy as heating 100l again from cold. it doesn't, it takes the same energy as heating 20l from cold.
Free lecky ? Hands up anyone here who has such a tariff
I wonder how they'll be wording that to avoid it being an obvious development of something that's been known about/used for ... well longer than I've been around.
Which is fine as long as you don't depart from those usage patterns. So, for example, family are round and grandchild needs a bath before bedtime - and due to "learning your usage patterns" the system doesn't have any hot water (unless you apply manual over-ride and use peak rate lecky).
Sorry, but you come across as a shill for something that seems to have more marketing hype than real substance.
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