Does Using A Light Dimmer Save Money?

T

Too_Many_Tools

Guest
I was recently asked whether using incandescent dimmers cuts electrical
costs.

When the lights are dimmed, is less electricity used or is it converted
to heat in the dimmer thereby still being consumed?

Thanks

TMT
 
Too_Many_Tools wrote:
I was recently asked whether using incandescent dimmers cuts electrical
costs.

When the lights are dimmed, is less electricity used or is it converted
to heat in the dimmer thereby still being consumed?

Thanks

TMT

You'll use less electricity.
Click to expand...

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"Too_Many_Tools" <too_many_tools@yahoo.com> schreef in bericht
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I was recently asked whether using incandescent dimmers cuts electrical
costs.

When the lights are dimmed, is less electricity used or is it converted
to heat in the dimmer thereby still being consumed?

Thanks

TMT
Click to expand...
These dimmers are meant for comfort, not for saving money. Yes, they use
little less power but produce much less light and almost the same amount of
heat. If you want to save money, you'd better use a lower power bulb.

petrus bitbyter
 
petrus bitbyter wrote:

"Too_Many_Tools" <too_many_tools@yahoo.com> schreef in bericht
news:1168733439.939482.120790@q2g2000cwa.googlegroups.com...

I was recently asked whether using incandescent dimmers cuts electrical
costs.

When the lights are dimmed, is less electricity used or is it converted
to heat in the dimmer thereby still being consumed?

Thanks

TMT



These dimmers are meant for comfort, not for saving money. Yes, they use
little less power but produce much less light and almost the same amount of
heat. If you want to save money, you'd better use a lower power bulb.

petrus bitbyter


They do NOT generate "almost the same amount of heat."
Click to expand...

Whether they save electricity depends on what setting you use. Turn
them down, and you can use a _lot_ less electricity (compared to when
they're turned all the way up).

By actual measurement (Kill-A-Watt):

50 watt (nominal) lamp

without dimmer: 58 watts

dimmer (a Leviton) turned all the way up: 57 watts

dimmer turned down until the light almost extinguished: 5 watts

Of course, this does NOT mean there aren't more efficient ways
to achieve low light levels. But I think it addresses the OP's
question.

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form che...@prodigy.net.
 
Thanks for the responses.

Could you go into the technical reasons why this is the case?

Thanks

TMT
Too_Many_Tools wrote:
I was recently asked whether using incandescent dimmers cuts electrical
costs.

When the lights are dimmed, is less electricity used or is it converted
to heat in the dimmer thereby still being consumed?

Thanks

TMT
Click to expand...
 
Too_Many_Tools wrote:
Thanks for the responses.

Could you go into the technical reasons why this is the case?
Click to expand...
I'll take a rough stab at it. You should be able to find much more info
via Google.

Modern dimmers work by switching on during each cycle at a point
determined by the desired brightness. If full brightness is called
for, (almost) the entire sine wave is passed. If less than full
brightness is called for, the device switches on later in the cycle
so only a portion of the complete sine wave reaches the bulb.

Power is the integral over time of voltage times current, so chopping
away part of the sine wave decreases the power the bulb gets.

Thanks

TMT
Too_Many_Tools wrote:

I was recently asked whether using incandescent dimmers cuts electrical
costs.

When the lights are dimmed, is less electricity used or is it converted
to heat in the dimmer thereby still being consumed?

Thanks

TMT
Click to expand...

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form che...@prodigy.net.
 
Thanks for the response.

This is my understanding of the principle of dimmers.

I was also wondering about the heat produced by the dimmer and how that
factored into the overall power used.

TMT

CJT wrote:
Too_Many_Tools wrote:
Thanks for the responses.

Could you go into the technical reasons why this is the case?


I'll take a rough stab at it. You should be able to find much more info
via Google.

Modern dimmers work by switching on during each cycle at a point
determined by the desired brightness. If full brightness is called
for, (almost) the entire sine wave is passed. If less than full
brightness is called for, the device switches on later in the cycle
so only a portion of the complete sine wave reaches the bulb.

Power is the integral over time of voltage times current, so chopping
away part of the sine wave decreases the power the bulb gets.

Thanks

TMT
Too_Many_Tools wrote:

I was recently asked whether using incandescent dimmers cuts electrical
costs.

When the lights are dimmed, is less electricity used or is it converted
to heat in the dimmer thereby still being consumed?

Thanks

TMT




--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form che...@prodigy.net.
Click to expand...
 
Too_Many_Tools wrote:
Thanks for the response.

This is my understanding of the principle of dimmers.

I was also wondering about the heat produced by the dimmer and how that
factored into the overall power used.

I believe heat production is mostly confined to while the actual
Click to expand...
switching is occurring, since when the device is off almost no current
flows and while it's on it exhibits a low resistance, so in either
instance I^2*R is low. Switching happens fast enough so that the heat
should be relatively small -- certainly small enough for the dimmer
to dissipate (although they can get quite warm).

I can't think of a simple experiment to quantify that for a real device,
unfortunately.

TMT

CJT wrote:

Too_Many_Tools wrote:

Thanks for the responses.

Could you go into the technical reasons why this is the case?


I'll take a rough stab at it. You should be able to find much more info
via Google.

Modern dimmers work by switching on during each cycle at a point
determined by the desired brightness. If full brightness is called
for, (almost) the entire sine wave is passed. If less than full
brightness is called for, the device switches on later in the cycle
so only a portion of the complete sine wave reaches the bulb.

Power is the integral over time of voltage times current, so chopping
away part of the sine wave decreases the power the bulb gets.


Thanks

TMT
Too_Many_Tools wrote:


I was recently asked whether using incandescent dimmers cuts electrical
costs.

When the lights are dimmed, is less electricity used or is it converted
to heat in the dimmer thereby still being consumed?

Thanks

TMT



--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form che...@prodigy.net.
Click to expand...

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form che...@prodigy.net.
 
"CJT" <abujlehc@prodigy.net> schreef in bericht
news:45A9914B.3010208@prodigy.net...
petrus bitbyter wrote:

"Too_Many_Tools" <too_many_tools@yahoo.com> schreef in bericht
news:1168733439.939482.120790@q2g2000cwa.googlegroups.com...

I was recently asked whether using incandescent dimmers cuts electrical
costs.

When the lights are dimmed, is less electricity used or is it converted
to heat in the dimmer thereby still being consumed?

Thanks

TMT



These dimmers are meant for comfort, not for saving money. Yes, they use
little less power but produce much less light and almost the same amount
of heat. If you want to save money, you'd better use a lower power bulb.

petrus bitbyter
They do NOT generate "almost the same amount of heat."

Whether they save electricity depends on what setting you use. Turn
them down, and you can use a _lot_ less electricity (compared to when
they're turned all the way up).

By actual measurement (Kill-A-Watt):

50 watt (nominal) lamp

without dimmer: 58 watts

dimmer (a Leviton) turned all the way up: 57 watts

dimmer turned down until the light almost extinguished: 5 watts

Of course, this does NOT mean there aren't more efficient ways
to achieve low light levels. But I think it addresses the OP's
question.

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form che...@prodigy.net.
Click to expand...
I'm fully understand the numbers you mentioned and I do not question their
correctness. The point is - and you'll know - that while turning low a
dimmer, the amount of light drops much faster then the amount of heat. So as
long as your dimmed bulb gives some usefull light, making more visible then
just itself, the amount of heat only dropped a little and your savings are
not substantial. Re-reading the question and my answer I agree it was not
clear enough.

petrus bitbyter
 
petrus bitbyter wrote:

"CJT" <abujlehc@prodigy.net> schreef in bericht
news:45A9914B.3010208@prodigy.net...

petrus bitbyter wrote:


"Too_Many_Tools" <too_many_tools@yahoo.com> schreef in bericht
news:1168733439.939482.120790@q2g2000cwa.googlegroups.com...


I was recently asked whether using incandescent dimmers cuts electrical
costs.

When the lights are dimmed, is less electricity used or is it converted
to heat in the dimmer thereby still being consumed?

Thanks

TMT



These dimmers are meant for comfort, not for saving money. Yes, they use
little less power but produce much less light and almost the same amount
of heat. If you want to save money, you'd better use a lower power bulb.

petrus bitbyter

They do NOT generate "almost the same amount of heat."

Whether they save electricity depends on what setting you use. Turn
them down, and you can use a _lot_ less electricity (compared to when
they're turned all the way up).

By actual measurement (Kill-A-Watt):

50 watt (nominal) lamp

without dimmer: 58 watts

dimmer (a Leviton) turned all the way up: 57 watts

dimmer turned down until the light almost extinguished: 5 watts

Of course, this does NOT mean there aren't more efficient ways
to achieve low light levels. But I think it addresses the OP's
question.

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form che...@prodigy.net.


I'm fully understand the numbers you mentioned and I do not question their
correctness. The point is - and you'll know - that while turning low a
dimmer, the amount of light drops much faster then the amount of heat. So as
long as your dimmed bulb gives some usefull light, making more visible then
just itself, the amount of heat only dropped a little and your savings are
not substantial. Re-reading the question and my answer I agree it was not
clear enough.

petrus bitbyter


A dimmed high wattage bulb is less efficient than a low wattage bulb in
Click to expand...
creating the same light. But the dimmer allows flexibility.

Agreed?

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form che...@prodigy.net.
 
"CJT" <abujlehc@prodigy.net> schreef in bericht
news:45AAE3DD.1090403@prodigy.net...
petrus bitbyter wrote:

"CJT" <abujlehc@prodigy.net> schreef in bericht
news:45A9914B.3010208@prodigy.net...

petrus bitbyter wrote:


"Too_Many_Tools" <too_many_tools@yahoo.com> schreef in bericht
news:1168733439.939482.120790@q2g2000cwa.googlegroups.com...


I was recently asked whether using incandescent dimmers cuts electrical
costs.

When the lights are dimmed, is less electricity used or is it converted
to heat in the dimmer thereby still being consumed?

Thanks

TMT



These dimmers are meant for comfort, not for saving money. Yes, they use
little less power but produce much less light and almost the same amount
of heat. If you want to save money, you'd better use a lower power bulb.

petrus bitbyter

They do NOT generate "almost the same amount of heat."

Whether they save electricity depends on what setting you use. Turn
them down, and you can use a _lot_ less electricity (compared to when
they're turned all the way up).

By actual measurement (Kill-A-Watt):

50 watt (nominal) lamp

without dimmer: 58 watts

dimmer (a Leviton) turned all the way up: 57 watts

dimmer turned down until the light almost extinguished: 5 watts

Of course, this does NOT mean there aren't more efficient ways
to achieve low light levels. But I think it addresses the OP's
question.

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form che...@prodigy.net.


I'm fully understand the numbers you mentioned and I do not question
their correctness. The point is - and you'll know - that while turning
low a dimmer, the amount of light drops much faster then the amount of
heat. So as long as your dimmed bulb gives some usefull light, making
more visible then just itself, the amount of heat only dropped a little
and your savings are not substantial. Re-reading the question and my
answer I agree it was not clear enough.

petrus bitbyter
A dimmed high wattage bulb is less efficient than a low wattage bulb in
creating the same light. But the dimmer allows flexibility.

Agreed?

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form che...@prodigy.net.
Click to expand...
Sure.

petrus bitbyter
 
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