On Thursday, 2 March 2017 20:55:16 UTC, jim wrote:
"Dave Plowman (News)" Wrote in message:
In article ,
jim k wrote:
"Dave Plowman (News)" Wrote in message:
In article ,
Brian Gaff wrote:
I don't think you quite got the question or maybe you are being
diplomatically thick.

I imagine what he means is, how much does the extra surface area in
those old cast radiators get more heat into a room over the normal
ones. Obviously if they were so efficient as to make the hot water cold
no other radiator would get hot would it!

It's the wrong word to use - strictly speaking. Normally efficiency as
regards a heater would be energy in versus heat out.

As you said what's wanted is the heat output of the various types of rad.


Depends how hot the water circulating through them is :-P

That would be a constant if quoting the heat output for comparison
pusposes?


Oooh so temp of water is same, but different radiator designs give
off more/less heat depending on their "ability to output heat
from system water at x degree C to room air"? But you tell me
it's not called efficiency....


I can see you never had an education.
Any heat not emitted from the radiator is not lost, it is returned to the boiler.
Ergo all radiators are 100% efficient.

Efficiency is a very exact technical term.
https://en.wikipedia.org/wiki/Efficiency