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Smitty Two

In article ,
(Doug Miller) wrote:

In article , Smitty Two
wrote:
In article ,
(Doug Miller) wrote:

In article , Smitty
Two
wrote:

A house is not a water heater. The overwhelming majority of the energy
used to maintain a water heater comes from *using* the hot water and
heating the replacement cold water. You aren't using the air in your
home, it's leaking out.

How is warm air leaking out of a house -- and consequently being replaced
by
colder air leaking in -- meaningfully different from warm water being
withdrawn from a water heater and being replaced by colder water?

The only one who coughed up anecdotal numbers from the real world in
this thread said his electric bill went down by $40 when he switched
from electricity to NG to heat his water.

Plausible IMHO.

Let's say 90% of that money went to heating cold water coming in, which
replaced the warm water going out. And 10% of that money went to making
up for "unintentional" heat loss.

Also plausible.

That's $4, total cost of unwanted heat loss. And let's say that turning
off the WH at night saves, oh, maybe 5% of the energy that leaving it on
all night uses. The OP defined all night as 10 hours.
(10/24)(0.05)($4.00) = $0.08.

I wonder at your guesstimate of 5% ...

I stand corrected. I said the OP couldn't save a plug nickel. My new
position is, he could save *eight cents per month.*

.. just off the cuff, I'd regard 20% as a more plausible figure -- which
brings the savings all the way up to a penny a day. Those pennies add up, you
know. ;-)

On second thought, I bet the timer costs .08 to run every month. I'm
going back to my plug nickel assertion.

Depends on which guesstimate is closer to correct: your 5%, or my 20%. I just
had a look at the Dayton Electric Timer which was left here by the previous
owner; it has a 3-watt motor. 3w * 24 hrs/day * 30 days/mo = 2160 watt-hrs/mo
= just over 2 kwh per month. Assume ten cents / kwh; at 5%, you're wasting
money, but at 20% you're saving. Not much, admittedly, but still non-zero.

I'll let you work out how long it takes to recoup the cost of the timer. :-)

You seem like a smart guy, Doug. I think you can figure out what I mean
when I say turning off a WH isn't the same as turning down the house
heat at night.

If by that you mean -- yes, the two situations operate on the same principle
exactly, but the amount of money saved on the water heater is so small as to
be not worth consideration -- then we agree. If you mean something other than
that, then we probably disagree.

Here is the difference to which I refer: You save money on the home
heating issue because you're lowering your average home temperature. You
don't save money (of any appreciable amount) on the hot water tank,
because you aren't lowering your hot water temperature. All you're doing
is making up the heat loss in one big chunk in the morning, instead of
incrementally throughout the night.