In article , T i m
writes
On Sat, 24 Dec 2016 20:02:31 +0000, rick
wrote:

On 24/12/2016 10:07, DerbyBorn wrote:
Are immersion heaters as efficient as they could be? Could the tubular
element be improved upon - or doesn't it matter?



I suppose you could improve on the design to allow it to get the heat
away quicker - .... by having a load of fins - and therefore create
surface area in contact with the water.

That is what I was reflecting.

Wouldn't make conversion of electricity to heat any more efficient.

So, if we put a 100kW heater in there and had it on for 1 second,
would the water end up as hot as if we put a 10kW heater in there and
had that on for 10 seconds? I'm not talking 'theoretically, I'm
talking real world here?

The (/my) 'big question' is that if (say) the heater element get's
sufficiently hot as to start to boil the surrounding water, *does* the
heat get carried into the water as effectively as if it wasn't
boiling?

No Go watch a saucepan of water coming to the boil.
If the answer is no, then you could see how if you increased the
surface are of the heater you decrease the energy / area and could
take it down to a level where there was no kettling.

Cost involved probably not worth any gain.

No, quite, but that wasn't really part of the question. ;-)

Cheers, T i m


--
bert