On Sat, 23 Jun 2012 23:05:14 -0700, mike wrote:

On 6/23/2012 9:35 PM, Winston wrote:
snip
Never asked them. But I did get the info directly from the IR output
of the smart meter and by timing the on-time of the water heater.

That's interesting! How did you do that, please?

The electric smart meter has an IR led that flashes in tune with
consumption.
For my meter, watts = 3600 * Frequency of the flash. Polk a PDA IR
sensor at it and calculate/graph consumption. Turns out that WalMart
sells cake slices in a plastic package that is a friction fit over the
meter and just the right size and shape to hold a PalmIII over the led.
Win-Win. Nice box and I get to eat cake.

You are a frugal genius. I am in awe.

Does a real-time plot of consumption. Another program reads the log and
lets me poke around on the graph to read instantaneous consumption and
the area under the curve for a selected region.

Pretty easy to identify the signatures of the water heater, heat pump,
fridge etc.

For stuff that unplugs, a Kil-A-Watt meter is a cheap monitor. There's
also a device that clamps on the electric meter and reads either the LED
or a rotating disk and wirelessly transmits real-time consumption
numbers. They have a computer interface, but it's too expensive for my
taste and it looks like the utility vendors that planned to support it
have backed out. I think it was called Microsoft HOHM. Blueline
Innovations is the vendor, but it's also marketed under other names.

Very interesting. Thanks!

(...)

Don't know what to tell you. The subconscious is a powerful thing. When
I had my house weatherized, I saw dramatic reductions in energy
consumption. Over time, it crept back up somewhat. I think the change
was due to me paying a LOT of attention to the numbers initially. The
consumption went back up somewhat when I quit fretting over it... and
subconsciously became less frugal.

Perhaps that is it.
I will have to make some time to gather the hard numbers, as you imply.

(...)

But lowering the thermostat will, if one's water heater is running
above optimum temperature. Or it should change, anyway.

Thermodynamically, the optimum temperature for a water heater is OFF.
For electric heat, 100% of the electricity gets converted to heat. I
have no experience with gas, but there may be some optimum on/off
profile for a gas water heater. There are losses up the flue. I don't
suspect it makes much difference.
In general, lower temperature reduces the losses from the heater
envelope and the pipes.

Yes.

For dilution I don't think it makes any difference. If you want a
gallon of 100F water, the temp of the hot and cold water mixed together
is irrelevant. If you mix it to 100F, you used the same number of
BTU's. That assumes that the cold temp into the heater was the same as
the current cold temp you're diluting with.

The thermostatically controlled mixer valves in my bathrooms
take care of that.

Low flow faucets in the bathroom sink made a change in hot water
consumption.
It now takes so long for the hot water to get to the bathroom that I
just use cold water. ;-)

Yup. I have to run about a gallon of water out of the pipes before
I get hot water in the bathrooms or kitchen. Instead, after working on
the car or in the yard, I'll put a load of laundry in the washer (located
a few inches from the water heater) push in the 'warm wash' button
temporarily and I have a washcloth full of nice warm water PDQ. A spritz
of foaming soap and I can clean up nice and quick without wasting undue
amounts of water or natural gas. Push the button for 'cold wash' and
let the washer do it's thing.

--Winston