On 24/12/2016 20:02, 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.
Wouldn't make conversion of electricity to heat any more efficient.

Surely the speed with which you can get the heat away can't exceed the
rate you stick it into the heater element? Or have they changed physics
again when I was not looking?

So if you are sticking electrical energy in at 3kW, and the element is
not in thermal runaway heating adiabatically, then its must be dumping
heat at a rate of 3kW also.

The only time more fins etc will start to pay dividends is where you
have a *much* more powerful heater that you could not thermally "couple"
to the water well enough to reach an equilibrium temperature on the
heater that is not so high as to destroy it.

Cost involved probably not worth any gain.

Alas the killer of many a good idea.

--
Cheers,

John.

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