Posted by danny burstein on April 13, 2009, 1:54 am
writes:
>Neon John:
>Here is a question (it might be a dumb question), From your answer you
>a basically saying that all electricity is converted to heat, is there
>anything else that electricity is converted to or is 100% of wattage
>input end up as heat?
In a typical residence or office, over 98 or so percent of the
electricity going into the room, regardless of what it's used
for, eventually turns to heat. The number is generally closer
to 100 percent than that, but some does "escape", so to speak,
as light going out through the windows.
There's only one use in a "regular" situation that would
lead to a lower number, and that's charging up a battery.
In a decent system, you might put as much as half or
even 3/4 of the electrity into "storage", and then
physically carry it out of there. (But remember that
your cellphone or even yur laptop only accounts for a
small amount of the power going into the room).
--
_____________________________________________________
Knowledge may be power, but communications is the key
dannyb@panix.com
[to foil spammers, my address has been double rot-13 encoded]
Posted by Eeyore on April 13, 2009, 6:19 pm
danny burstein wrote:
> >Neon John:
> >Here is a question (it might be a dumb question), From your answer you
> >a basically saying that all electricity is converted to heat, is there
> >anything else that electricity is converted to or is 100% of wattage
> >input end up as heat?
> In a typical residence or office, over 98 or so percent of the
> electricity going into the room, regardless of what it's used
> for, eventually turns to heat. The number is generally closer
> to 100 percent than that, but some does "escape", so to speak,
> as light going out through the windows.
> There's only one use in a "regular" situation that would
> lead to a lower number, and that's charging up a battery.
But the 'wasted' energy heats the battery. It's been converted to ( rather
unhelpful )
thermal energy.
Graham
Posted by Eeyore on April 13, 2009, 6:18 pm
"Fred F." wrote:
> Neon John:
> Here is a question (it might be a dumb question), From your answer you
> a basically saying that all electricity is converted to heat, is there
> anything else that electricity is converted to or is 100% of wattage
> input end up as heat?
It doesn't matter if the source is electricity or not.
http://en.wikipedia.org/wiki/Conservation_of_energy
Graham
Posted by Curbie on April 13, 2009, 3:01 am
>The answer to your question is simple. With the one exception of a
>heat pump moving heat from the outside, the heat gain of any
>electrical device is exactly 1. One watt of heat out for one watt of
>electricity in. To convert to BTU, multiply watts by 3.415179 BTU/hr.
John,
After you know the answer, it is simple and obvious once you think
about it, if the electrical device is inside your house the
electricity it uses eventually is turned into heat gain. Wouldn't your
heat pump example hold true for outside AC compressors too, the
electricity is used outside but the results (cool in this example)
effect inside temperature (negative heat gain)?
I too saved your Soldering to aluminum post. (Thanks for that, and...)
Thanks for reminding me to look both ways before crossing the street.
Curbie
Posted by Eeyore on April 13, 2009, 6:23 pm
Curbie wrote:
> >The answer to your question is simple. With the one exception of a
> >heat pump moving heat from the outside, the heat gain of any
> >electrical device is exactly 1. One watt of heat out for one watt of
> >electricity in. To convert to BTU, multiply watts by 3.415179 BTU/hr.
> After you know the answer, it is simple and obvious once you think
> about it, if the electrical device is inside your house the
> electricity it uses eventually is turned into heat gain. Wouldn't your
> heat pump example hold true for outside AC compressors too, the
> electricity is used outside but the results (cool in this example)
> effect inside temperature (negative heat gain)?
Heat pumps are quite a different matter. They 'transport' heat from one
place to another.
http://en.wikipedia.org/wiki/Heat_pump
Additionally say if required for heating, the energy input can also be used
to heat the premises due to the law of conservation of energy.
Also read about CoP.
http://en.wikipedia.org/wiki/Heat_pump#Efficiency
Graham
>Here is a question (it might be a dumb question), From your answer you
>a basically saying that all electricity is converted to heat, is there
>anything else that electricity is converted to or is 100% of wattage
>input end up as heat?