Dave Plowman (News) wrote:

In article ,
Roger Hayter wrote:
wrote:

On Saturday, 4 July 2020 13:32:04 UTC+1, Roger Hayter wrote:
Max Demian wrote: On 04/07/2020 11:55,
Dave Plowman (News) wrote: In article
,
tabbypurr wrote: On Friday, 3 July 2020 11:19:23 UTC+1, Dave
Plowman (News) wrote: So you stand by his
claim that an electric convector heater is 100% efficient?
Just curious. I said some are, not all are. Oil
filled ones that overheat, glow red hot & catch fire may
have more heat output than input And
those that simply expand? As all will? It only expands
once. After that it is 100% efficient. And, of course, the
heat stored during expansion will be released when it cools down.
Obvious to everyone but Dave. Pressing a spring by expansion
then releasing it by unexpanding doesn't really do any work, it
just temporarily stores some energy. He'll never get it
though. He still thinks a resistor turning electricity to heat is
imposible.
NT

Of course in the spring case some of the energy is lost as heat, but in
the heater case none need be lost as mechanical work.

I'll say again. Nothing in this world is 100% efficient. Of course you can
approach it with some things. But never achieve it.

Why do you think that nothing is 100% efficient? The only reason for
believing this that I know of is a a thermodynamic one, and this does
not apply ot heat production as an endpoint. Though it certainly would
apply to heat *transfer*, but we are not talking about this.

--

Roger Hayter