Anyone know the kW rating of a screw-in coil?

[Ric2013]

Anyone familiar with those nasty cylinder coils that screw into an immersion boss as a cheap and nasty way of turning a single coil cylinder into a twin coil (well, sort-of)? A customer has a slow-heating cylinder that is using one of these (surprise, surprise). Just wondered what sort of rate of heat transfer one might expect if it is working correctly?

 

[ShaunCorbs]

Couple of ks max probably more like 1

 

[Ric2013]

Cool thanks! and another few characters

 

[John.g]

Not less than 2kw, a dual immersion might have a 2kw Sink 11" element and the Bath 24/36" element 3kw, you often see them at 2.75kw each, the Sink element will heat say 30L from 15C to 60C in 30 to 45 minutes and the longer 3kw Bath one will heat say 200L in ~ 3.5 hrs. You can't or shouldn't have both (wired to be) on together.

 

[Ric2013]

Not less than 2kw, a dual immersion might have a 2kw Sink 11" element and the Bath 24/36" element 3kw, you often see them at 2.75kw each, the Sink element will heat say 30L from 15C to 60C in 30 to 45 minutes and the longer 3kw Bath one will heat say 200L in ~ 3.5 hrs. You can't or shouldn't have both (wired to be) on together.

Not an electric immersion heater. It's a coil of copper tube that water runs through from the primary circuit and it screws into an immersion boss.

 

[John.g]

Ah yes, I have seen one used for a very small (single panel) solar installation, it seemed to work reasonably well, I think its surface area was somewhere around 0.2m2 vs a bog standard coil of around 0.65m2.

 

[ShaunCorbs]

Pigs tail or hot rod normally 12mm tube etc