On 31-Mar-2004, "Roland Paterson-Jones" wrote:

Mmm, hot water delivered is 114F, that's 45C, hardly luke-warm!

We have to take the rest of the measurements with a pinch of salt then.

As you know, heat loss is proportional to the temperature delta. How about a
realistic scenario.

OK, let's bump the temperature up to 125F. That's a temperature differential
of 64F.

That means the heat loss and cost increases by a factor of 64/51.

The average heat loss cost at 114F is $4/month, so at 125F it will be $5.02.
(4*64/51)

But, of course, don't forget that many people keep their water heaters in areas
that are warmer than 61F, so the temperature differential may be lower than
mine.

The main issue with electric water heaters, as far as I'm concerned, is that
the Carnot-limited power source wastes at least 60% of the fuel source heat
to the local rivers and dams, for you to take the (optimistic) 40% and
convert it back to heat.

I have absolutely no control over that nor was my study directed at that issue.

Your case study is flawed, and you lack appreciation of the big picture.

I never claimed to be presenting either a study or a solution to the "big
picture" of energy usage. My study was simply to measure the actual heat loss
energy for one water heater in a known environment. As shown above, you can
adapt the figures to other situations.