I installed sixteen dimmer switches around the house, for various purposes.
Don't have any problems at all, but am curious.

When a dimmer switch is turned down so the light is not as bright, does this
save electricity or does the dimmer switch disperse the voltage drop in
heat?

Thanks for the info. Bob

Bob wrote:
I installed sixteen dimmer switches around the house, for various
purposes. Don't have any problems at all, but am curious.

When a dimmer switch is turned down so the light is not as bright,
does this save electricity or does the dimmer switch disperse the
voltage drop in heat?

Thanks for the info. Bob

Modern home dimmer switch do save energy. Of course they do consume
some heat and most lamps when dimmed are somewhat less efficient. So if you
had 10 lamps in the room you could dim them all 50% or turn half of them off
and save a little more energy.

--
Joseph Meehan

Dia 's Muire duit

Joseph Meehan wrote:

... if you had 10 lamps in the room you could dim them all 50% or
turn half of them off and save a little more energy.

Wikipedia says the power used and light output of an incandescent bulb are
proportional to V^1.6 and V^3.4, so light is proportional to V^(3.4/1.6)
= P^2.125, no? Turning half off makes half the light with half the power,
but dimming all to 50% power only makes 0.5^2.1225, ie 23% of the light.

Making 50% of the light requires dimming them all to 0.5^(1/2.125), ie
72% of the original power. That's a lot vs a little more energy, IMO.

Then again, CFs are 4X more efficient, and some dimmable CFs have
a light output that's directly proportional to power :-)

Nick

You do save alot but im not sure about nicks numbers, To get an
incandesant to light when its output might be 1/ 100th or less I found
mine took 6-8v. I believe at 50% power you get less than 50% light
output. But incandesants can last 10 times more at 50% and nearly
indefinatly at 10% power, but this does not apply to halogens.

On Jan 27, 8:15 am, wrote:
Joseph Meehan wrote:
... if you had 10 lamps in the room you could dim them all 50% or
turn half of them off and save a little more energy.Wikipedia says the power used and light output of an incandescent bulb are
proportional to V^1.6 and V^3.4, so light is proportional to V^(3.4/1.6)
= P^2.125, no? Turning half off makes half the light with half the power,
but dimming all to 50% power only makes 0.5^2.1225, ie 23% of the light.

Making 50% of the light requires dimming them all to 0.5^(1/2.125), ie
72% of the original power. That's a lot vs a little more energy, IMO.

Then again, CFs are 4X more efficient, and some dimmable CFs have
a light output that's directly proportional to power :-)

Nick



Another Nick classic. Quick with the numbers and clueless as
usual. The guy didn't ask if a bulb that is at half brightness uses
less energy. Any dummy knows that. What he asked was whether the
energy saved at the bulb just shows up as energy wasted at the
dimmer. Which of course it doesn;t because dimmers are Triacs.

wrote:
...
Another Nick classic. Quick with the numbers and clueless as
usual. The guy didn't ask if a bulb that is at half brightness uses
less energy. Any dummy knows that. What he asked was whether the
energy saved at the bulb just shows up as energy wasted at the
dimmer. Which of course it doesn;t because dimmers are Triacs.

I guess that could be called a trader4 classic since not all dimmers are
triacs.

His numbers are correct and I believe he properly addressed the
question. Often a question calls for additional information.

--
Joseph Meehan

Dia 's Muire duit

On Jan 27, 11:15 am, "Joseph Meehan"
wrote:
wrote:..

Another Nick classic. Quick with the numbers and clueless as
usual. The guy didn't ask if a bulb that is at half brightness uses
less energy. Any dummy knows that. What he asked was whether the
energy saved at the bulb just shows up as energy wasted at the
dimmer. Which of course it doesn;t because dimmers are Triacs. I guess that could be called a trader4 classic since not all dimmers are
triacs.

His numbers are correct and I believe he properly addressed the
question. Often a question calls for additional information.

--
Joseph Meehan

Dia 's Muire duit



Sorry, but I have to disagree. All Nick addressed was how much
energy is consumed in the light bulbs. That was not the question.
We all know a bulb that is burning at half brightness is going to use
less energy. The question was whether the energy saved in the light
bulb is just dissipated instead in the dimmer. And it would be if
the dimmer were a resistor.

On Jan 27, 11:15 am, "Joseph Meehan"
wrote:
wrote:..

Another Nick classic. Quick with the numbers and clueless as
usual. The guy didn't ask if a bulb that is at half brightness uses
less energy. Any dummy knows that. What he asked was whether the
energy saved at the bulb just shows up as energy wasted at the
dimmer. Which of course it doesn;t because dimmers are Triacs. I guess that could be called a trader4 classic since not all dimmers are
triacs.


The OP says he installed 16 dimmer switches in his house. When is
the last time you saw a house dimmer switch that wasn't semiconductor/
Triac based? Every one you can buy down at the home center is.
And that was precisely the issue of the OP's question. Because these
type that use semiconducotrs and have been around for decades do not
just produce a voltage drop like a resistor would. If the dimmer was
resistor based, then it would just dissipate the energy instead of the
dimmed bulb and you would not save energy by dimming the bulb. That
was the question, which asked if the energy that doesn't go to the
bulb was not just dissipated as a voltage drop in the dimmer.




His numbers are correct and I believe he properly addressed the
question. Often a question calls for additional information.

--
Joseph Meehan

Dia 's Muire duit

"Bob" wrote in message
...
I installed sixteen dimmer switches around the house, for various purposes.
Don't have any problems at all, but am curious.

When a dimmer switch is turned down so the light is not as bright, does
this
save electricity or does the dimmer switch disperse the voltage drop in
heat?

Thanks for the info. Bob

They do save, but not directly proportional to the voltage drop. Your bulbs
will last longer also since they are not operating at full temperature.

On Jan 27, 8:34 am, "Edwin Pawlowski" wrote:
"Bob" wrote in ...

I installed sixteen dimmer switches around the house, for various purposes.
Don't have any problems at all, but am curious.

When a dimmer switch is turned down so the light is not as bright, does
this
save electricity or does the dimmer switch disperse the voltage drop in
heat?

Thanks for the info. BobThey do save, but not directly proportional to the voltage drop. Your bulbs
will last longer also since they are not operating at full temperature.


The type of dimmers under discussion are semiconductor based, using
Triacs. They are not variable resistor based, which would just
dissipate the energy that is not going to the lights, producing no
energy savings. The Triacs work instead by delaying turning on the
output voltage for part of the 60Hz sine wave, essentially chopping
off varying portions of the leading edge. That chopping action,
which turns a nice sine wave into something with a fast rising edge,
is also what produces RF intereference that is common with these.
There is of course some energy lost as heat in the dimmer, so they are
not 100% efficient, as you can tell by touching one. But a light
dimmed with one of these does save a substantial amount of energy.

Edwin Pawlowski wrote:
....


They do save, but not directly proportional to the voltage drop. Your
bulbs will last longer also since they are not operating at full
temperature.

I might add that while that is true for most all lamps, under some
conditions (generally when dimmed between about 40-60% halogen lamps will
actually have reduced life. Kind of knit picking. :-)

Also while and not sure exactly what trader4 was trying to say, but you
are correct about the savings not being directly proportional.


--
Joseph Meehan

Dia 's Muire duit

Joseph Meehan wrote:

I might add that while that is true for most all lamps, under some
conditions (generally when dimmed between about 40-60% halogen lamps will
actually have reduced life. Kind of knit picking. :-)

And, as a further example, that should be "nit" not "knit", Joseph. G

Particularly relevant to this thread, given one of the definitions of
"nit", dontcha' think?

http://en.wikipedia.org/wiki/Nit_%28unit%29

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.98*10^14 fathoms per fortnight.

Jeff Wisnia wrote:
Joseph Meehan wrote:

I might add that while that is true for most all lamps, under
some conditions (generally when dimmed between about 40-60% halogen
lamps will actually have reduced life. Kind of knit picking. :-)

And, as a further example, that should be "nit" not "knit", Joseph.
G

I knew I would get caught on that one. I just could not think of the
correct spelling so I did SWAG and was wrong. :-)


Particularly relevant to this thread, given one of the definitions of
"nit", dontcha' think?

http://en.wikipedia.org/wiki/Nit_%28unit%29

Jeff

--
Joseph Meehan

Dia 's Muire duit

On Sat, 27 Jan 2007 04:38:53 -0600, "Bob"
wrote:

I installed sixteen dimmer switches around the house, for various purposes.
Don't have any problems at all, but am curious.

When a dimmer switch is turned down so the light is not as bright, does this
save electricity or does the dimmer switch disperse the voltage drop in
heat?

Thanks for the info. Bob



I put in newer electronic dimmers, and part of their advertisement,
was they reduce electricity, and extend bulb life. I don't
remembering it be 1 for 1 relationship. Example, 50% setting saved
40% and extended bulbs life like 25%.

Just what I remember...

tom @ www.FreeCreditCheckGuide.com