Re: Suspension losses

Am Mon, 13 Jan 2025 12:58:35 -0500 schrieb Frank Krygowski
<frkrygow@sbcglobal.net>:

On 1/13/2025 12:06 PM, Wolfgang Strobl wrote:

Am Mon, 13 Jan 2025 11:03:03 -0500 schrieb Frank Krygowski
<frkrygow@sbcglobal.net>:
 

On 1/13/2025 8:57 AM, zen cycle wrote:

On 1/13/2025 2:01 AM, Jeff Liebermann wrote:

On Mon, 13 Jan 2025 13:20:04 +0700, John B. <slocombjb@gmail.com>
wrote:
>

But long before the days of transistors and "circuit boards" my folks
had an electric blanket... used it all the rest of their lives. Is the
modern one better?

>
Not really better, but certainly safer.  Electric heaters are all 100%
efficient.  Every watt you shove into the heating wires is turned into
heat.  There's no way to improve on 100% efficiency.

>
Nothing is 100% efficient

>
It's certainly true that 100% of the electricity consumed by an electric
blanket becomes heat.

 
But that 100% isn't efficiency, it's just a raw conversion rate for
Electricity to heat in an isolated blanket.

>
ISTM a good definition of efficiency is "Desired output divided by
input." Since the desired output is heat, I think it's 100% efficient.

"desired output" does some heavy lifting, here.  What about the desired
input?

Textbook definitions from a specific context are often quite misleading,
when used in a different context. Rolf Mantel just gave an example for
that in <vm38of$1qe41$1@dont-email.me>, there are many more.

>

You, as a person, don't need or consume heat. Somewhat simplified, you
need a certain range of temperatures.  In the ideal case, you don't need
any additional energy, because your body already produces heat. A little
bit of isolation, perhaps provided by that very blanket, might be
sufficient. 

>
And, I suppose, we could do away with all home heating, and just wear
very heavy clothing all winter. But I don't know of anyone doing that.

Actually, we added some isolation to our house, last year. The reduced
energy consumption was quite noticeable and better than we expected. No
heavy clothing necessary.  It's an old house, unfortunately some
regulations prohibit doing more or would make it very expensive. Decades
ago, a former colleague build a house according to current standards
from that time, heated by a heat pump and geothermics. Compared to the
quoted 100 % "efficiency" of your heated blanket, that heating is ~750%
efficient. While riding over the land during in 2021ff, I saw not only
many new collectors on the roofs, mostly photovoltaic now, people were
isolating their freestanding houses to such an extent that you would
hardly believe it if you hadn't seen it.

>
>

->
<https://www.sciencedirect.com/science/article/abs/pii/S0301421514002638>
 
"A brighter future? Quantifying the rebound effect in energy efficient
lighting"
 
<https://www.arquiled.com/en/avoiding-the-rebound-effect-when-transitioning-to-led/>
 
"In Portugal, the average amount of light has risen 120% in the last
five years. It is urgent to prevent the energy savings associated with
the transition to LED from being offset by unnecessary lighting"

>
I don't perceive that to be a serious problem, at least indoors.

The difference between the expected and actual efficiency is independent
of whether the lighting is installed indoors or outdoors.

But there is indeed another and additional problem caused by too much
light outside: Both astronomers and wildlife are not happy about the
increasing light pollution. And, to be honest, I don't like the fact
that you can hardly see the stars anywhere these days either.

If the
objective is to expend less energy, it's still been achieved.

If you are allowed to move the goalpost, the goal is already guaranteed.

>
I'm not a fan of overly bright headlamps nor outdoor light pollution,
but those seem to be separate issues.

That is true, but obviously no argument. Light pollution is just another
detriment of wasting energy by unnecessary lighting.


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