Hi Brains, a question is there any saving on energy by using a dimmer ?
Thankx

On Fri, 18 Nov 2005 09:56:17 -0000, taxpayer wrote:


Hi Brains, a question is there any saving on energy by using a dimmer ?

Not in the grand scheme of things. You might save two bucks in a year.
Or there might not even be any savings at all if you frequently operate
the lights at 75% brightness, due to the dimmer's inefficiencies.

taxpayer wrote:

Hi Brains, a question is there any saving on energy by using a dimmer ?
Thankx


depends on where you set it -- and on what basis you calculate the
savings (e.g. if the alternative is smaller bulbs, then probably not)

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taxpayer wrote:
Hi Brains, a question is there any saving on energy by using a dimmer ?
Thankx




Well the lamps use less power when dimmed, they're less efficient too,
but if you need full brightness sometimes and not others then yes a
dimmer will give you some savings, but convenience is the main reason
for installing one.

A dimmer will not save very much in power consumption. When the lamp is
dimmed, it is less efficient. Its heater resistance will go down a little,
thus it will not draw much less current in relation to the loss of light
output.

What you should really be going for, is to use a smaller wattage bulb, or
get rid of the dimmer and use a compact fluorescent lamp. These lamps are
about 85% efficient, and will consume much less power. It is not recommended
to use a dimmer on a compact fluorescent lamp, unless it is a model that is
designed to do so. If you try it on a dimmer and it is not rated, there is a
chance that both the dimmer and the lamp will be damaged.

--

JANA
_____


"taxpayer" wrote in message
...
Hi Brains, a question is there any saving on energy by using a dimmer ?
Thankx

James Sweet wrote:
taxpayer wrote:

Hi Brains, a question is there any saving on energy by using a dimmer ?
Thankx




Well the lamps use less power when dimmed, they're less efficient too,
but if you need full brightness sometimes and not others then yes a
dimmer will give you some savings, but convenience is the main reason
for installing one.
Light goes down with ~ 4th power of current and temperature
so at 50% light you still consume 70-85 % of full power + dimmer
power. Dimming ordinary lightbulbs is a very inefficient way to
save power. (Sometimes it may look great!! -)-)-) )

The biggest savings might be prolonging the light bulb life, if you
always dial up the light so that you have eliminated the cold filament
inrush current that occurs when you have the light on a regular switch.

H. R.(Bob) Hofmann

writes:

The biggest savings might be prolonging the light bulb life, if you
always dial up the light so that you have eliminated the cold filament
inrush current that occurs when you have the light on a regular switch.

Please let's ont start a thread on this - again...

The slow inrush has only a very small effect on lamp life.

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
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Sam Goldwasser wrote:
writes:


The biggest savings might be prolonging the light bulb life, if you
always dial up the light so that you have eliminated the cold filament
inrush current that occurs when you have the light on a regular switch.


Please let's ont start a thread on this - again...

The slow inrush has only a very small effect on lamp life.



That and incandescent lamps cost virtually nothing, you can get four for
a buck, though I don't use them for much of anything anymore.

James Sweet wrote:

Sam Goldwasser wrote:

writes:


The biggest savings might be prolonging the light bulb life, if you
always dial up the light so that you have eliminated the cold filament
inrush current that occurs when you have the light on a regular switch.



Please let's ont start a thread on this - again...

The slow inrush has only a very small effect on lamp life.



That and incandescent lamps cost virtually nothing, you can get four for
a buck, though I don't use them for much of anything anymore.

Same here -- that's probably why they're so cheap.

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The e-mail address in our reply-to line is reversed in an attempt to
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Thanks guys

James Sweet writes:

Sam Goldwasser wrote:
writes:

The biggest savings might be prolonging the light bulb life, if you
always dial up the light so that you have eliminated the cold filament
inrush current that occurs when you have the light on a regular switch.
Please let's ont start a thread on this - again...
The slow inrush has only a very small effect on lamp life.

That and incandescent lamps cost virtually nothing, you can get four
for a buck, though I don't use them for much of anything anymore.

Yep:

Cost of 100 W incandescent lamp: $0.25.

Cost of electricity to run 100 W incandescent
lamp over its life (750 hours): $7.50 or more.

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name is included in the subject line. Or, you can
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"Sam Goldwasser" wrote in message
...
writes:

The biggest savings might be prolonging the light bulb life, if you
always dial up the light so that you have eliminated the cold filament
inrush current that occurs when you have the light on a regular switch.

Please let's ont start a thread on this - again...

The slow inrush has only a very small effect on lamp life.


Does that also apply to LV halogen lighting? I have a few halogen fittings
in my home, and the bulbs definitely last a lot longer in the one I have
with an 'electronic' transformer which ramps the bulbs up rather than
switching on instantaneously. I fact I don't recall changing a bulb in it in
the three or so years it's been up. OTOH the iron transformer instant-on
ones pop bulbs every few months, though that could be down to a less stable
transformer output.

I'm wondering if the slow-on is a way of protecting the SMPS from being
blown if a bulb blows, IOW it ramps the output up and checks for overcurrent
before applying full voltage, rather than being a bulb-saving feature?

Dave

Your greatest savings will come from the increase in the life
of the light bulbs.

taxpayer wrote:
Hi Brains, a question is there any saving on energy by using a dimmer ?
Thankx

"Dave D" writes:

"Sam Goldwasser" wrote in message
...
writes:

The biggest savings might be prolonging the light bulb life, if you
always dial up the light so that you have eliminated the cold filament
inrush current that occurs when you have the light on a regular switch.

Please let's ont start a thread on this - again...

The slow inrush has only a very small effect on lamp life.


Does that also apply to LV halogen lighting? I have a few halogen fittings
in my home, and the bulbs definitely last a lot longer in the one I have
with an 'electronic' transformer which ramps the bulbs up rather than
switching on instantaneously. I fact I don't recall changing a bulb in it in
the three or so years it's been up. OTOH the iron transformer instant-on
ones pop bulbs every few months, though that could be down to a less stable
transformer output.

To some extent is should apply. Even with the halogen cycle, there will
still be portions of the filament that get narrower, and these dissipate
a higher proportion of the power. Eventually, they being the weak link,
will fail.

I'm wondering if the slow-on is a way of protecting the SMPS from being
blown if a bulb blows, IOW it ramps the output up and checks for overcurrent
before applying full voltage, rather than being a bulb-saving feature?

Might be but that sounds like a lot more intelligence than I'd expect
of a power supply!

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
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JANA wrote:
A dimmer will not save very much in power consumption. When the lamp is
dimmed, it is less efficient. Its heater resistance will go down a little,
thus it will not draw much less current in relation to the loss of light
output.

What you should really be going for, is to use a smaller wattage bulb, or
get rid of the dimmer and use a compact fluorescent lamp. These lamps are
about 85% efficient, and will consume much less power. It is not recommended
to use a dimmer on a compact fluorescent lamp, unless it is a model that is
designed to do so. If you try it on a dimmer and it is not rated, there is a
chance that both the dimmer and the lamp will be damaged.

--

JANA
_____


"taxpayer" wrote in message



...
Hi Brains, a question is there any saving on energy by using a dimmer ?
Thankx

I have used the dimmer type fluorescent lamps. Very nice. Too bad they
don't have more on the market, as such, they are expensive. Payed about
$20 for one at The Home Depot, then I could not find them there. It
also was a very nice color. I use vertually all fluorescent
lamps when I can. Leave one on outside all day long. The 5 pack for $10
at The Home Depot lamps are very nice. I had installed halogen recessed
kitchen lamps in previous home. They were too bright for normal
viewing, so a dimmer was mandatory, and they do save money and heat.
Now the thing I want to know, is how the two fluorescent lamps differ
in circuitry, and how that can cost $18.

greg

writes:

JANA wrote:
A dimmer will not save very much in power consumption. When the lamp is
dimmed, it is less efficient. Its heater resistance will go down a little,
thus it will not draw much less current in relation to the loss of light
output.

What you should really be going for, is to use a smaller wattage bulb, or
get rid of the dimmer and use a compact fluorescent lamp. These lamps are
about 85% efficient, and will consume much less power. It is not
recommended to use a dimmer on a compact fluorescent lamp, unless it is
a model that is designed to do so. If you try it on a dimmer and it is
not rated, there is a chance that both the dimmer and the lamp will be
damaged.

I guess what you meant was 15 percent efficient at producing useful light.
This is still 3 times the efficiency of a typical incandescent lamp.

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name is included in the subject line. Or, you can
contact me via the Feedback Form in the FAQs.

I have used the dimmer type fluorescent lamps. Very nice. Too bad they
don't have more on the market, as such, they are expensive. Payed about
$20 for one at The Home Depot, then I could not find them there. It
also was a very nice color. I use vertually all fluorescent
lamps when I can. Leave one on outside all day long. The 5 pack for $10
at The Home Depot lamps are very nice. I had installed halogen recessed
kitchen lamps in previous home. They were too bright for normal
viewing, so a dimmer was mandatory, and they do save money and heat.
Now the thing I want to know, is how the two fluorescent lamps differ
in circuitry, and how that can cost $18.

greg




A lot of it is construction quality, but dimming ballasts have special
considerations. They have to provide active cathode heat which is
inversely proportional to arc current otherwise the cathodes will
sputter badly as the lamp is dimmed. This is even more tricky to do well
when you can't have a separate dimmer circuit independent of power
supplied to the lamp.

Market share is another factor, there simply isn't as much market for
dimmable CFLs, hence the higher price.