On Dec 4, 7:07*pm, Edward Reid
wrote:
On Sat, 4 Dec 2010 08:05:36 -0800 (PST), harry
wrote:

That is called the Coefficient Of Performance.
http://en.wikipedia.org/wiki/Coeffic...rmance#Example

Again, nothing to do with efficiency.

In that sense, everything is 100% efficient, because mass-energy is
always conserved.

This viewpoint however is not particularly useful to someone trying to
figure out how to heat a house.

For a discussion of efficiency to be meaningful, you have to say what
you are measuring with respect to. Absolutes are not useful.

Edward

Efficiency is a scientific term and thus scientifically defined.
I wish you'd get your brain into gear before your fingers. Spend ten
seconds checking the facts & then you wouldn't appear half so foolish.

http://en.wikipedia.org/wiki/Energy_...ion_efficiency

The thread is about water heaters not heating houses.
But if you want to know about that, start a thread and I can explain
that too.
You need to start with the theory and then move on to the practical
matter of how to apply it.