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| David Williams 2007-06-03, 9:25 pm |
| Hereabouts, incandescent lightbulbs are being phased out and will be
illegal in five years. We are all being encouraged to use
energy-efficient compact fluorescent bulbs. In fact, they are being
given away for free in some places, to encourage people to switch.
We are also encouraged to use dimmer switches, so that we can save
energy by dimming our lights when we don't need them bright.
However... Dimmer switches and compact fluorescent bulbs won't work
together. A friend of mine tried to dim one of these bulbs, and it
promptly stopped working, permanently.
There is another kind of efficient light that I know can be used with
dimmers, namely Light Emitting Diodes. On TV, I have seen bulbs
consisting of clusters of LEDs arranged so they can be screwed into a
standard light socket. But I haven't seen any of these devices for sale
anywhere.
Does anyone know where to get them?
dow
| |
|
|
"David XXXXXXXX" <david.XXXXXXXX@bayman.org> wrote in message
news:1180921787.912.0@bayman.org...
> Hereabouts, incandescent lightbulbs are being phased out and will be
> illegal in five years. We are all being encouraged to use
> energy-efficient compact fluorescent bulbs. In fact, they are being
> given away for free in some places, to encourage people to switch.
>
> We are also encouraged to use dimmer switches, so that we can save
> energy by dimming our lights when we don't need them bright.
>
> However... Dimmer switches and compact fluorescent bulbs won't work
> together. A friend of mine tried to dim one of these bulbs, and it
> promptly stopped working, permanently.
>
> There is another kind of efficient light that I know can be used with
> dimmers, namely Light Emitting Diodes. On TV, I have seen bulbs
> consisting of clusters of LEDs arranged so they can be screwed into a
> standard light socket. But I haven't seen any of these devices for sale
> anywhere.
>
> Does anyone know where to get them?
>
> dow
Here's one. They are expensive.
http://www.cyberguys.com/templates/...productID=13113
| |
|
| They cost alot right now.
And they aren't as energy efficient as compact flourescents.
You could still use some sort of halogen lighting for dimmers and the prices
will drop for LEDs and I sure they will increase their efficiencies over
time.
"David XXXXXXXX" <david.XXXXXXXX@bayman.org> wrote in message
news:1180921787.912.0@bayman.org...
> Hereabouts, incandescent lightbulbs are being phased out and will be
> illegal in five years. We are all being encouraged to use
> energy-efficient compact fluorescent bulbs. In fact, they are being
> given away for free in some places, to encourage people to switch.
>
> We are also encouraged to use dimmer switches, so that we can save
> energy by dimming our lights when we don't need them bright.
>
> However... Dimmer switches and compact fluorescent bulbs won't work
> together. A friend of mine tried to dim one of these bulbs, and it
> promptly stopped working, permanently.
>
> There is another kind of efficient light that I know can be used with
> dimmers, namely Light Emitting Diodes. On TV, I have seen bulbs
> consisting of clusters of LEDs arranged so they can be screwed into a
> standard light socket. But I haven't seen any of these devices for sale
> anywhere.
>
> Does anyone know where to get them?
>
> dow
| |
| David Williams 2007-06-04, 1:25 pm |
| -> They cost alot right now.
-> And they aren't as energy efficient as compact flourescents.
-> You could still use some sort of halogen lighting for dimmers and the prices
-> will drop for LEDs and I sure they will increase their efficiencies over
-> time.
I'm not sure that halogen lamps will remain legal when the law against
incandescent lighting comes into effect.
I guess I'll just have to hope that the price of LED lamps drops a lot
over the next few years.
dow
| |
| Vaughn Simon 2007-06-04, 5:25 pm |
|
"David XXXXXXXX" <david.XXXXXXXX@bayman.org> wrote in message
news:1180921787.912.0@bayman.org...
However... Dimmer switches and compact fluorescent bulbs won't work
> together. A friend of mine tried to dim one of these bulbs, and it
> promptly stopped working, permanently.
Others have explained why LEDs are not yet a good option. Dimmable compact
fluorescents are hard to find, particularly if you want a special shape or
style, but they exist and they represent your best option right now if you must
have dimmers.
Actually, I find that I can get along pretty well without dimmers.
Traditionally, one reason for dimmers is to save energy. Compact fluorescents
are so efficient, there is less reason to bother dimming them. If you want mood
lighting, install a separate fixture with a small bulb.
One big frustration I run into is that it currently seems to be impossible
to buy a remote controlled ceiling fan without a dimmer. You would think that
they would include a dip switch setting to defeat the dimming feature so that
you can use normal CF lamps.
Vaughn
| |
| David Williams 2007-06-06, 3:25 am |
| -> Others have explained why LEDs are not yet a good option. Dimmable com
-> fluorescents are hard to find, particularly if you want a special shape or
-> style, but they exist and they represent your best option right now if you m
-> have dimmers.
-> Actually, I find that I can get along pretty well without dimmers.
-> Traditionally, one reason for dimmers is to save energy. Compact fluorescen
-> are so efficient, there is less reason to bother dimming them. If you want
-> lighting, install a separate fixture with a small bulb.
-> One big frustration I run into is that it currently seems to be impossi
-> to buy a remote controlled ceiling fan without a dimmer. You would think th
-> they would include a dip switch setting to defeat the dimming feature so tha
-> you can use normal CF lamps.
-> Vaughn
Actually, I do have a dimmable fluorescent lamp. I bought it at a
discount store several years ago. It isn't a compact bulb, but a
"torchiere" lamp, which stands on the floor and has the lamp a bit above
head height, shining upward onto the ceiling. It gives a nice, indirect
light. It is dimmable with a knob on the stand, and the dimming does
work, but it isn't as good as a regular dimmer with an incandescent
lamp. For one thing, it won't dim all the way down to zero. Its minimum
brightness is, I'd guess, about half the maximum.
My girlfriend bought an identical lamp at the same time, but after a
while the fluorescent tube in hers burned out. We have looked hard to
find a replacement, but without success. It's a special kind of tube,
with six electrical contacts. I have no idea how the dimmer works, but
it must have six output lines.
A few months ago, I saw an item on TV about some people who have
invented a dimmer for fluorescent lamps. I wasn't too impressed, since
I had one already. But, as far as I could see, theirs works with
regular fluorescent tubes. Like the one I have, it dims down to only
about half the maximum brightness.
I have seen compact fluorescent bulbs that work in "tri-light" fittings
so they can be switched to three brightnesses. There are two tubes, of
unequal powers, and either or both can be switched on, giving three
output levels. I guess this is better than nothing, but not as nice as
a real dimmer.
I do like to be able to dim lamps. Low illumination is good for
watching TV, for example - and other things. Also, of course, it saves
energy.
I have never seen a compact fluorescent bulb that will work with a
regular dimmer switch. That is what is needed, at a reasonable price.
I agree with your comment about fans. I guess that, as CF lamps become
more common, fans will be produced that can use them without
destroying them.
dow
| |
| Martin Riddle 2007-06-06, 8:25 pm |
|
"David XXXXXXXX" <david.XXXXXXXX@bayman.org> wrote in message
news:1181068916.912.1180999617@bayman.org...
>-> Others have explained why LEDs are not yet a good option. Dimmable
>com
> -> fluorescents are hard to find, particularly if you want a special shape
> or
> -> style, but they exist and they represent your best option right now if
> you m
> -> have dimmers.
>
> -> Actually, I find that I can get along pretty well without dimmers.
> -> Traditionally, one reason for dimmers is to save energy. Compact
> fluorescen
> -> are so efficient, there is less reason to bother dimming them. If you
> want
> -> lighting, install a separate fixture with a small bulb.
>
> -> One big frustration I run into is that it currently seems to be
> impossi
> -> to buy a remote controlled ceiling fan without a dimmer. You would
> think th
> -> they would include a dip switch setting to defeat the dimming feature
> so tha
> -> you can use normal CF lamps.
>
> -> Vaughn
>
> Actually, I do have a dimmable fluorescent lamp. I bought it at a
> discount store several years ago. It isn't a compact bulb, but a
> "torchiere" lamp, which stands on the floor and has the lamp a bit above
> head height, shining upward onto the ceiling. It gives a nice, indirect
> light. It is dimmable with a knob on the stand, and the dimming does
> work, but it isn't as good as a regular dimmer with an incandescent
> lamp. For one thing, it won't dim all the way down to zero. Its minimum
> brightness is, I'd guess, about half the maximum.
>
> My girlfriend bought an identical lamp at the same time, but after a
> while the fluorescent tube in hers burned out. We have looked hard to
> find a replacement, but without success. It's a special kind of tube,
> with six electrical contacts. I have no idea how the dimmer works, but
> it must have six output lines.
>
I have one of those Halogen Torchiere lamps. Tossed teh Halogen and wired up
two light buld sockets. With a 15W CF its just as bright as the halogen, and
softer too. I was thinking of a 2PDT switch and two different sizes of CF's.
The problem with CF and Dimmers is that most CF are not Power factor
corrected. They just draw a spike of current off the peak of the AC wave.
No SCR can handle that.
If you find a CF with 0.99 PFC then you probably can dim it like most of
todays Fluroesant fixutres.
Cheers
Cheers
| |
| David Williams 2007-06-07, 3:25 am |
| -> I have one of those Halogen Torchiere lamps. Tossed teh Halogen and wired up
-> two light buld sockets. With a 15W CF its just as bright as the halogen, and
-> softer too. I was thinking of a 2PDT switch and two different sizes of CF's.
-> The problem with CF and Dimmers is that most CF are not Power factor
-> corrected. They just draw a spike of current off the peak of the AC wave.
-> No SCR can handle that.
-> If you find a CF with 0.99 PFC then you probably can dim it like most of
-> todays Fluroesant fixutres.
-> Cheers
The torchiere I mentioned is *not* a halogen one. (I do have a halogen
one too, but the one I wrote about has a fluorescent tube.)
If you try to dim a CF with a regular dimmer, the CF fails. The triac
remains fine. The circuitry in the base of the bulb can't handle a
non-sine waveform.
The basic problem with dimming fluorescent lamps (note the spelling,
please!) is that a sufficient amount of power has to be dissipated to
keep the mercury vaporized. If the power goes down too much, the
mercury condenses and the arc fails to strike on the next half-cycle. I
suppose it would be possible to keep the electrodes hot by running the
heaters full-time, but if the objective is to save energy, this isn't a
good way to achieve it!
dow
| |
| philkryder 2007-06-08, 9:25 am |
| On Jun 6, 8:32 pm, david.willi...@bayman.org (David XXXXXXXX) wrote:
....
>
> The torchiere I mentioned is *not* a halogen one. (I do have a halogen
> one too, but the one I wrote about has a fluorescent tube.)
>
Yeah, I bought 3 of those at Home Depot - Mine were GE with a special
bulb.
We broke two of the Torchieres, but the bulbs still work in the
original and I think I bought a spare.
Must be nearly 7 years old by now...
the bulb may be available at Amazon:
http://www.amazon.com/Compact-Fluor...s/dp/B000089DBT
Some CFs ara marked dimmable.
http://www.nolico.com/saveenergy/23...mable_swirl.htm
| |
|
|
"David XXXXXXXX" <david.XXXXXXXX@bayman.org> wrote in message
news:1180921787.912.0@bayman.org...
> Hereabouts, incandescent lightbulbs are being phased out and will be
> illegal in five years. We are all being encouraged to use
> energy-efficient compact fluorescent bulbs. In fact, they are being
> given away for free in some places, to encourage people to switch.
>
> We are also encouraged to use dimmer switches, so that we can save
> energy by dimming our lights when we don't need them bright.
>
> However... Dimmer switches and compact fluorescent bulbs won't work
> together. A friend of mine tried to dim one of these bulbs, and it
> promptly stopped working, permanently.
>
> There is another kind of efficient light that I know can be used with
> dimmers, namely Light Emitting Diodes. On TV, I have seen bulbs
> consisting of clusters of LEDs arranged so they can be screwed into a
> standard light socket. But I haven't seen any of these devices for sale
> anywhere.
>
> Does anyone know where to get them?
>
> dow
None of the proposed state legislation that I've seen (some 16 states now)
talk about phasing out bulbs other than the standard household types.
Halogen and special-purpose bulbs are exempt. Compact fluorescent are the
most efficient alternatives because LEDs are only about 30-40 lumens/watt
(good quality white light) compared to CFLs at 80 lpw. The LEDs that are
jammed into shapes that look like standard bulbs look like kluges. They're
expensive and don't give much light.
TKM
| |
| Larry L [in Honolulu] 2007-06-12, 8:25 pm |
| "TKM" <nomail@no.net> wrote in
news:p0gbi.143478$p47.40951@bgtnsc04-news.ops.worldnet.att.net:
>
> "David XXXXXXXX" <david.XXXXXXXX@bayman.org> wrote in message
> news:1180921787.912.0@bayman.org...
>
> None of the proposed state legislation that I've seen (some 16 states
> now) talk about phasing out bulbs other than the standard household
> types. Halogen and special-purpose bulbs are exempt. Compact
> fluorescent are the most efficient alternatives because LEDs are only
> about 30-40 lumens/watt (good quality white light) compared to CFLs at
> 80 lpw. The LEDs that are jammed into shapes that look like standard
> bulbs look like kluges. They're expensive and don't give much light.
>
And there's part of the CFL stuff that never gets talked about. My Sister
lives up in the mountains in Colorado, where she runs her heating most of
the year. Think about this, if you have heat on, all those savings with
the CFLs disappear. A plain old incandescent "wastes" energy by
converting much of what it uses into heat. All that heat is lost by CFLs
and then must be replaced by the electric heating elements. It's exactly
the same heat and exactly the same cost.
In those situations, there is ZERO advantage to a CFL. Granted the
majority of the population uses air conditioning some of the year, but
many do not, and any time you're using electric heat, CFLs are not
helping at all.
Larry L
| |
| Vaughn Simon 2007-06-12, 8:25 pm |
|
"Larry L [in Honolulu]" <larry@no-place.org> wrote in message
news:466f2402$0$5209$4c368faf@roadrunner.com...
> All that heat is lost by CFLs
Huh? The heat is not "lost", it was just never made in the first place.
> and then must be replaced by the electric heating elements. It's exactly
> the same heat and exactly the same cost.
Only true if you are using electric resistance heating. If you are using a
heat pump, it should be far more efficient than resistance heating. If you are
using gas, they you are probably getting your BTUs far cheaper than if you were
using resistance heating.
> In those situations, there is ZERO advantage to a CFL.
As noted above, this is a wrong statement.
> Granted the
> majority of the population uses air conditioning some of the year, but
> many do not, and any time you're using electric heat, CFLs are not
> helping at all.
Wrong again.
Vaughn
| |
| Steve Spence 2007-06-12, 8:25 pm |
| Electric heat? You have bigger problems that lighting to worry about. Get
rid of the electric heating, then worry about getting efficient lighting.
--
Steve Spence
Director, Green-Trust
http://www.green-trust.org
"Larry L [in Honolulu]" <larry@no-place.org> wrote in message
news:466f2402$0$5209$4c368faf@roadrunner.com...
> "TKM" <nomail@no.net> wrote in
> news:p0gbi.143478$p47.40951@bgtnsc04-news.ops.worldnet.att.net:
>
> And there's part of the CFL stuff that never gets talked about. My Sister
> lives up in the mountains in Colorado, where she runs her heating most of
> the year. Think about this, if you have heat on, all those savings with
> the CFLs disappear. A plain old incandescent "wastes" energy by
> converting much of what it uses into heat. All that heat is lost by CFLs
> and then must be replaced by the electric heating elements. It's exactly
> the same heat and exactly the same cost.
>
> In those situations, there is ZERO advantage to a CFL. Granted the
> majority of the population uses air conditioning some of the year, but
> many do not, and any time you're using electric heat, CFLs are not
> helping at all.
>
> Larry L
| |
| Larry L [in Honolulu] 2007-06-13, 9:25 am |
| "Steve Spence" <sspence@green-trust.org> wrote in
news:466efb29_2@newsfeed.slurp.net:
> Electric heat? You have bigger problems that lighting to worry about.
> Get rid of the electric heating, then worry about getting efficient
> lighting.
>
I love the simplistic answers to complex questions! Perhaps in spite of
all your experience and knowledge you don't realize that "Getting rid of
electric heat" is, for some people simply not practical. There are many
neighborhoods which do not have gas lines, and where propane or butane
delivery is not practical due to the expense, such as in places in the
mountains of Colorado where I pointed out I was talking about.
I live in Hawaii, where almost no one even has heat, as none is required.
I wasn't talking about where you live, Steve, or where I live. I was
simply pointing out that hard rules about what's best are almost always
incorrect for some, such as the idea that CFLs are better for everyone.
Larry L
| |
| Vaughn Simon 2007-06-13, 9:25 am |
|
"Larry L [in Honolulu]" <larry@no-place.org> wrote in message
news:466fba5b$0$30664$4c368faf@roadrunner.com...
> such as the idea that CFLs are better for everyone.
CFLs are better for virtually everyone, they are certainly better for the
planet. Heating with light bulbs (as you suggest) is very inefficient.
Vaughn
| |
| Anthony Matonak 2007-06-13, 9:25 am |
| Vaughn Simon wrote:
> "Larry L [in Honolulu]" <larry@no-place.org> wrote in message
> news:466fba5b$0$30664$4c368faf@roadrunner.com...
>
> CFLs are better for virtually everyone, they are certainly better for the
> planet. Heating with light bulbs (as you suggest) is very inefficient.
Not to mention that electric lights aren't usually designed for heating.
They don't have thermostats and are aren't placed to circulate heated
air. If you already use electric heating then you won't lose anything by
switching to more efficient lights.
Anthony
| |
| Eeyore 2007-06-13, 1:25 pm |
|
"Larry L [in Honolulu]" wrote:
> "TKM" <nomail@no.net> wrote in
> news:p0gbi.143478$p47.40951@bgtnsc04-news.ops.worldnet.att.net:
>
>
> And there's part of the CFL stuff that never gets talked about. My Sister
> lives up in the mountains in Colorado, where she runs her heating most of
> the year. Think about this, if you have heat on, all those savings with
> the CFLs disappear. A plain old incandescent "wastes" energy by
> converting much of what it uses into heat. All that heat is lost by CFLs
> and then must be replaced by the electric heating elements. It's exactly
> the same heat and exactly the same cost.
Relatively few places get electricity as cheap as whatever they use for space
heating.
There's usually a good cost based reason to use CFLs.
Graham
| |
| sylvan butler 2007-06-13, 5:25 pm |
| On Wed, 13 Jun 2007 10:08:34 GMT, Vaughn Simon <vaughnsimonHATESSPAM@att.FAKE.net> wrote:
> CFLs are better for virtually everyone, they are certainly better for the
> planet.
Uh, maybe. Maybe not. CFLs are not a 100% sure thing.
> Heating with light bulbs (as you suggest) is very inefficient.
No, heating with a light bulb is essentially 100% efficient. Sure,
you'll lose a little bit out the windows, but the escaping light costs
you far less heat than the other losses thru the same windows.
sdb
--
What's seen on your screen? http://pcscreenwatch.com
sdbuse1 on mailhost bigfoot.com
| |
| Tony Wesley 2007-06-13, 5:25 pm |
| On Jun 13, 4:59 pm, sylvan butler
<ZsdbUse1+noZs_0...@Zbigfoot.Zcom.invalid> wrote:
> On Wed, 13 Jun 2007 10:08:34 GMT, Vaughn Simon <vaughnsimonHATESS...@att.FAKE.net> wrote:
>
> No, heating with a light bulb is essentially 100% efficient.
Which is much worse than what you'd get with a heat pump.
| |
| Vaughn Simon 2007-06-13, 8:25 pm |
|
"sylvan butler" <ZsdbUse1+noZs_0706@Zbigfoot.Zcom.invalid> wrote in message
news:slrnf70mma.6tj.ZsdbUse1+noZs_0706@sdba64.internal...
> On Wed, 13 Jun 2007 10:08:34 GMT, Vaughn Simon
> <vaughnsimonHATESSPAM@att.FAKE.net> wrote:
>
> Uh, maybe. Maybe not. CFLs are not a 100% sure thing.
>
>
> No, heating with a light bulb is essentially 100% efficient.
No it is not, First, as Tony pointed out (and I pointed out earlier) it is
far less efficient than a heat pump. Also, your light bulb "heater" must depend
on natural convection, yet it will often be located in a very inefficient
location for this, such as near a ceiling.
Further, the light bulb acts as a heater whenever you turn it on, not just
when you happen to need heat. The heat it generates is 100% wasted on a warm
day when you don't happen to need heat. Worse yet, if you have AC, you have to
expend energy to pump the waste heat from the bulb out of your home.
>Sure,
> you'll lose a little bit out the windows, but the escaping light costs
> you far less heat than the other losses thru the same windows.
I don't know what the above means, so I won't argue.
If after reading all of this you still want your energy waster, be my
guest. I am done with this idiocy.
Vaughn
>
> sdb
> --
> What's seen on your screen? http://pcscreenwatch.com
> sdbuse1 on mailhost bigfoot.com
| |
| Martin 2007-06-18, 1:25 pm |
| On Jun 6, 10:32 pm, david.willi...@bayman.org (David XXXXXXXX) wrote:
> If you try to dim a CF with a regular dimmer, the CF fails. The triac
> remains fine. The circuitry in the base of the bulb can't handle a
> non-sine waveform.
>
>
I have not found this to be the case. I power standard CF bulbs at my
campsite with a rectangular-wave cheapie inverter, and have not seen
and CF failures in this application. They seem to run a very slight
bit dimmer on inverter power versus sinewave.
| |
| sylvan butler 2007-06-21, 5:25 pm |
| On Wed, 13 Jun 2007 23:48:44 GMT, Vaughn Simon <vaughnsimonHATESSPAM@att.FAKE.net> wrote:
>
> "sylvan butler" <ZsdbUse1+noZs_0706@Zbigfoot.Zcom.invalid> wrote in message
> news:slrnf70mma.6tj.ZsdbUse1+noZs_0706@sdba64.internal...
>
> No it is not,
Yes, it is.
> First, as Tony pointed out (and I pointed out earlier) it is
> far less efficient than a heat pump.
Sometimes. The efficiency of a heat pump can be greater than 100%, or
if the temperature of the source is near or below freezing, a heat pump
will be much less than 100% efficient. None of which affects the
efficiency of a light bulb as a heater.
> Also, your light bulb "heater" must depend
> on natural convection, yet it will often be located in a very inefficient
> location for this, such as near a ceiling.
Heat distribution is not a factor in heat production efficiency ratings.
> Further, the light bulb acts as a heater whenever you turn it on, not just
> when you happen to need heat. The heat it generates is 100% wasted on a warm
> day when you don't happen to need heat. Worse yet, if you have AC, you have to
> expend energy to pump the waste heat from the bulb out of your home.
None of which changes the heating efficiency of a light bulb.
The simple fact is, a light bulb is essentially 100% efficient at
turning electrical energy into heat.
> If after reading all of this you still want your energy waster, be my
> guest. I am done with this idiocy.
Thank you!
sdb
--
What's seen on your screen? http://pcscreenwatch.com
sdbuse1 on mailhost bigfoot.com
| |
| Neon John 2007-06-21, 8:25 pm |
| On Thu, 21 Jun 2007 15:37:27 -0600, sylvan butler
>The simple fact is, a light bulb is essentially 100% efficient at
>turning electrical energy into heat.
Not "essentially", exactly 100% efficient. Every single quanta of energy that comes
in over the electrical circuit goes out as some form of heat.
John
--
John De Armond
See my website for my current email address
http://www.neon-john.com
http://www.johndearmond.com <-- best little blog on the net!
Cleveland, Occupied TN
I love cats ... they taste just like chicken.
| |
| Steve Cothran 2007-06-21, 8:25 pm |
| On Wed, 13 Jun 2007 15:27:47 GMT, Eeyore
<rabbitsfriendsandrelations@hotmail.com> wrote:
>
>Relatively few places get electricity as cheap as whatever they use for space
>heating.
At my house this moment, propane (70% Furnace) is 32.96US per mbtu
and electricity is 24.94US.
Either you guys get cheap heating fuel or pay a lot for electricity.
| |
| Tony Wesley 2007-06-21, 9:25 pm |
| On Jun 21, 5:37 pm, sylvan butler
<ZsdbUse1+noZs_0...@Zbigfoot.Zcom.invalid> wrote:
> On Wed, 13 Jun 2007 23:48:44 GMT, Vaughn Simon <vaughnsimonHATESS...@att.FAKE.net> wrote:
[color=darkred]
> Heat distribution is not a factor in heat production efficiency ratings.
That's correct, it doesn't affect the efficiency in BTUs produced.
However, the light bulb may be less efficient than resistive heating
in warming the occupant(s) of the house due to the location of the
heating element.
| |
| Donald Kinney 2007-06-22, 3:25 am |
| >>The simple fact is, a light bulb is essentially 100% efficient at
> Not "essentially", exactly 100% efficient. Every single quanta of
> energy that comes in over the electrical circuit goes out as some
> form of heat.
> John
Gee, I always thought that Radiant Energy and Thermal Energy were
different...
So if 100 percent is in the form of heat (thermal energy) where does the
light (radiant energy) come from?
Donald
| |
| Tony Wesley 2007-06-22, 3:25 am |
| On Jun 21, 10:07 pm, Steve Cothran <f...@fake.com> wrote:
> On Wed, 13 Jun 2007 15:27:47 GMT, Eeyore
>
> <rabbitsfriendsandrelati...@hotmail.com> wrote:
>
[color=darkred]
> At my house this moment, propane (70% Furnace) is 32.96US per mbtu
> and electricity is 24.94US.
>
> Either you guys get cheap heating fuel or pay a lot for electricity.
I just ran the numbers, looking at my last bill. Assuming I did all
the conversions right, here's what I got...
1 mbtu is 293 kilowatt hours and costs $33.59.
1 mbtu is 9.71 CCF of natural gas (100% efficiency) and costs $14.25.
At 70% efficiency, is 13.87 CCF, costs $20.35.
So BTU from electric heat is 33.59/20.35 or 1.65 times as much as
natural gas.
As an aside, what does propane cost in bulk? My experience is limited
to 20 lb bottles for the bbq.
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| David Williams 2007-06-22, 3:25 am |
| -> Gee, I always thought that Radiant Energy and Thermal Energy were
-> different...
-> So if 100 percent is in the form of heat (thermal energy) where does the
-> light (radiant energy) come from?
-> Donald
No. Basically, they're the same thing.
In an incandescent lightbulb, 100% of the electrical energy is
converted into heat in the filament. The filament emits what you call
"radiant energy", which carries most of the heat away. (A small amount
of heat is conducted away along the wires that support the filament,
and through the gas in the bulb.) The electromagnetic radiation
("radiant energy") is partly absorbed by the glass of the bulb, which
becomes hot, and that heat is removed by convection in the surrounding
air, and by conduction and radiation. The rest of the radiation from
the filament, a small part of which is visible light, goes out into the
surrounding environment, where it is absorbed by the things it strikes,
being converted back into heat. Possibly, a small amount of light finds
its way out into outer space, and travels away indefinitely. This is
the *only* part of the original electrical energy that does not end up
as heat in the bulb or in surrounding objects that have absorbed
radiation.
The energy is interconverted between radiation and thermal energy
(vibrations of molecules, etc.) many times. Basically, they are both
forms of the same thing - "heat".
Almost all other electrical appliances are also 100 percent efficient
*as heaters*, except for any energy that goes out into space. The only
exceptions are things like battery chargers which convert some of the
electrical energy into another form which is stored indefinitely.
dow
| |
| Steve Cothran 2007-06-22, 9:25 am |
| On Fri, 22 Jun 2007 03:34:41 -0000, Tony Wesley <tonywesley@gmail.com>
wrote:
>I just ran the numbers, looking at my last bill. Assuming I did all
>the conversions right, here's what I got...
>
>1 mbtu is 293 kilowatt hours and costs $33.59.
That 293 KWH in the Tn Valley costs $24.90US, but it is still more
than your NG cost. Maybe I need to move where there are gas lines...
>
>1 mbtu is 9.71 CCF of natural gas (100% efficiency) and costs $14.25.
>At 70% efficiency, is 13.87 CCF, costs $20.35.
>
>So BTU from electric heat is 33.59/20.35 or 1.65 times as much as
>natural gas.
>
>As an aside, what does propane cost in bulk? My experience is limited
>to 20 lb bottles for the bbq.
Last Propane I bought was 2.10US/Gal. At that price I could heat
cheaper with resistance strips, but I'm opting for a heat pump.
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