Yeah yeah, if you have an incandescent bulb that you leave on for
hours and hours, it would save energy to swap it out for a CFL. But
you could save even more by just TURNING IT OFF.

I jumped on the CFL bandwagon with a bunch of bulbs, but only
afterwards (yeah, mea culpa) started to pay close attention to the
duty cycle on those lights. A CFL bulb (any FL light) takes an
initial surge of power to start, plus it only has so many starts in it
from the day it is built. They only save on longer duty cycles.

Quite a lot of the lights in our house are used for only a couple of
minutes at a time, if that. Like our main hallways have switches at
either end and the middle (entry point there also). At night, enter
on one end, turn on light; exit other end, turn off light. Less than
a minute.

In Master Bath, separate WC and Lav areas; go in to pee, turn on
light; finished turn off light. In morning go to sink area, turn on
light, shave; finished turn off light. Less than 5 minutes either
application.

Now that I'm paying attention, I am probably going to switch some of
them back. Until I do, we find ourselves leaving lights on longer in
order to save starts, and also because of the feeling that the longer
they are on, the more we are saving!




Reply to NG only - this e.mail address goes to a kill file.

"v" wrote in message
...

Quite a lot of the lights in our house are used for only a couple of
minutes at a time, if that. Like our main hallways have switches at
either end and the middle (entry point there also). At night, enter
on one end, turn on light; exit other end, turn off light. Less than
a minute.

Perhaps you can find in the USA what are marketed
in France as "minuteries" which turn off a light after a
(programmable?) X seconds. They were prima facie
invented for staircases in walkup apartment buildings.
You turn on the light as you enter the staircase, then
forget about it even if your hands are not full. The
gadget automatically turns off the light (usually when
you just dropped your key.)

--
Don Phillipson
Carlsbad Springs
(Ottawa, Canada)

v wrote:
... A CFL bulb (any FL light) takes an
initial surge of power to start, plus it only has so many starts in it
from the day it is built. They only save on longer duty cycles.

The initial surge thing using a "lot" of electricity is somewhat of a
myth. Work it out and there's just no way that a fraction of a second
surge can use all that much electricity. If it did the wires would
melt and the circuit breakers blow.

WDS wrote:
v wrote:
... A CFL bulb (any FL light) takes an
initial surge of power to start, plus it only has so many starts in it
from the day it is built. They only save on longer duty cycles.

The initial surge thing using a "lot" of electricity is somewhat of a
myth. Work it out and there's just no way that a fraction of a second
surge can use all that much electricity. If it did the wires would
melt and the circuit breakers blow.


Exactly. This myth was busted on Mythbusters on TV. They tested a
variety of bulbs ie, regular filament, halogen, metal vapor, etc
against FL and compact FLs. They measured the power used. The
conclusion was, while they did use more energy during a fraction of a
sec during start up, it only took at most a few more secs for the FLs
to come out ahead. And after that, they used a small fraction of the
energy of the other bulbs. The only bulbs that were even better were
LED type.

You may not like the light you get from CFL for all applications. And
they do take maybe 20 secs to reach full brightness when they are used
in cold areas, like an unheated garage in winter. (At least all the
ones I've tried so far have had this problem) But, they do exactly
what is claimed, which is to save a lot of energy cost.

wrote...


WDS wrote:
v wrote:
... A CFL bulb (any FL light) takes an
initial surge of power to start, plus it only has so many starts in it
from the day it is built. They only save on longer duty cycles.

The initial surge thing using a "lot" of electricity is somewhat of a
myth. Work it out and there's just no way that a fraction of a second
surge can use all that much electricity. If it did the wires would
melt and the circuit breakers blow.


Exactly. This myth was busted on Mythbusters on TV. They tested a
variety of bulbs ie, regular filament, halogen, metal vapor, etc
against FL and compact FLs. They measured the power used. The
conclusion was, while they did use more energy during a fraction of a
sec during start up, it only took at most a few more secs for the FLs
to come out ahead. And after that, they used a small fraction of the
energy of the other bulbs. The only bulbs that were even better were
LED type.

You may not like the light you get from CFL for all applications. And
they do take maybe 20 secs to reach full brightness when they are used
in cold areas, like an unheated garage in winter. (At least all the
ones I've tried so far have had this problem) But, they do exactly
what is claimed, which is to save a lot of energy cost.

From what's available in my area, there are pretty much three "colors" of
CFLs. One is quite warm and nice and a great substitute for incadescents in
most living areas. If in your neck of the woods, Home Depot tends to stock
all three "flavors."

Another advantage to CFLs that I haven't seen discussed is their use in
many new light fixtures. So often, I see stand-alone or wall/ceiling mounted
fixtures with a 60-watt maximum warning label, probably due to worries about
heat. Many times, 60 watts of incandescent light just doesn't offer what the
room needs. But with a larger-than-the-tiniest CFL, you still can meet the
wattage warning while offering much more light than a 60-w incandescent can
do.

Craig

"...plus it only has so many starts in it
from the day it is built. They only save on longer duty cycles."

I understand that your concern is that a CFL will die too soon if you
keep turning it on and off too often. But note that the vast majority
of them come with a 5-7 year warranty. So if it breaks before 5 years,
take it back to the store, get your money back, and buy a new one.

"Craig" wrote in message
...

wrote...


WDS wrote:
v wrote:
... A CFL bulb (any FL light) takes an
initial surge of power to start, plus it only has so many starts in it
from the day it is built. They only save on longer duty cycles.

The initial surge thing using a "lot" of electricity is somewhat of a
myth. Work it out and there's just no way that a fraction of a second
surge can use all that much electricity. If it did the wires would
melt and the circuit breakers blow.


Exactly. This myth was busted on Mythbusters on TV. They tested a
variety of bulbs ie, regular filament, halogen, metal vapor, etc
against FL and compact FLs. They measured the power used. The
conclusion was, while they did use more energy during a fraction of a
sec during start up, it only took at most a few more secs for the FLs
to come out ahead. And after that, they used a small fraction of the
energy of the other bulbs. The only bulbs that were even better were
LED type.

You may not like the light you get from CFL for all applications. And
they do take maybe 20 secs to reach full brightness when they are used
in cold areas, like an unheated garage in winter. (At least all the
ones I've tried so far have had this problem) But, they do exactly
what is claimed, which is to save a lot of energy cost.

From what's available in my area, there are pretty much three "colors" of
CFLs. One is quite warm and nice and a great substitute for incadescents
in most living areas. If in your neck of the woods, Home Depot tends to
stock all three "flavors."

Another advantage to CFLs that I haven't seen discussed is their use in
many new light fixtures. So often, I see stand-alone or wall/ceiling
mounted fixtures with a 60-watt maximum warning label, probably due to
worries about heat. Many times, 60 watts of incandescent light just
doesn't offer what the room needs. But with a larger-than-the-tiniest CFL,
you still can meet the wattage warning while offering much more light than
a 60-w incandescent can do.

Craig

The above is correct. Any power surge with any light source at turn-on is
brief (milliseconds) and, as far as CFLs are concerned, the surge is tiny
compared to what is drawn by incandescent and incandescent/halogen sources.
You'll have to be counting fractions of a penny to see any of those surges
on your monthly electric bill.

All fluorescent lamps are sensitive to on/off switching, however. The
reason is that starting a fluorescent lamp sputters off a bit of the
material coating the cathodes inside the tube. When that material is gone,
the lamp flickers or doesn't start and that's end of life for the lamp.
Newer lamps, including CFLs, are less sensitive to starts than older lamps;
but there is still some reduction in lamp life when lamps are switched.

CFLs that are Energy Star listed have to pass a "Rapid Cycle Stress Test"
(5 minutes on, 5 minutes off once every two hours of rated lamp life) and
they have to have a rated life of 6,000 hours or more (50% failures of a
group of lamps = time of rated life). Energy Star says that 6,000 hours is
about 5 years of residential use.

See:
http://www.energystar.gov/ia/partner...s_prog_req.pdf

So, if your CFLs are Energy Star listed and not performing up to Energy Star
standards, you should ask for a refund or replacement lamps from the
manufacturer and Energy Star will be interested in knowing as well.

But screwing a CFL into a socket designed for incandescent lamps, while
convenient, is a compromise. Fluorescent lamps work best in dedicated
sockets where the ballast is separated from the heat of the lamp. The
number of fluorescent lighting fixtures designed for residential use is
growing (see www.lightingfortomorrow.com for award-winning examples) and
companies such as Lithonia and Sea Gull Lighting have extensive lines. Too
bad that fixtures stores and home centers don't stock more of the good ones.

TKM

wrote:
"...plus it only has so many starts in it
from the day it is built. They only save on longer duty cycles."

I understand that your concern is that a CFL will die too soon if you
keep turning it on and off too often. But note that the vast majority
of them come with a 5-7 year warranty. So if it breaks before 5 years,
take it back to the store, get your money back, and buy a new one.


Incandescant light bulbs are also affected by how many times they are
turned off and on. They will last for a substantially longer time if
left on continuously than if they are switched on and off for short
periods.

wrote in message
ups.com...

wrote:
"...plus it only has so many starts in it
from the day it is built. They only save on longer duty cycles."

I understand that your concern is that a CFL will die too soon if you
keep turning it on and off too often. But note that the vast majority
of them come with a 5-7 year warranty. So if it breaks before 5 years,
take it back to the store, get your money back, and buy a new one.


Incandescant light bulbs are also affected by how many times they are
turned off and on. They will last for a substantially longer time if
left on continuously than if they are switched on and off for short
periods.

No. Think about flashing sign lamps, for example. Lamp life is similar to
non-flashing lamps. Only when incandescent lamps are near their normal
end-of-life does turning them on and off make a difference. That difference
is minor according to the research reports and amounts to only a few hours;
but it explains why lamps so often fail when turned on.

From the standpoint of cost, however, it's always better to turn a lamp off
if you don't need the light since the cost of energy to operate any lamp
designed for general lighting service is typically 80-90 percent of the cost
of providing light.

TKM

TKM wrote:
wrote in message
ups.com...

wrote:
"...plus it only has so many starts in it
from the day it is built. They only save on longer duty cycles."

I understand that your concern is that a CFL will die too soon if you
keep turning it on and off too often. But note that the vast majority
of them come with a 5-7 year warranty. So if it breaks before 5 years,
take it back to the store, get your money back, and buy a new one.


Incandescant light bulbs are also affected by how many times they are
turned off and on. They will last for a substantially longer time if
left on continuously than if they are switched on and off for short
periods.

No. Think about flashing sign lamps, for example. Lamp life is similar to
non-flashing lamps.

Oh, really? What flashing lamps specifically are you talking about?
Like say am auto turn signal that from experience fail about as often
as say a headlight, even though the turn signal is only on a tiny
fraction of the time that a headlight is on?

If you watch the Mythbusters show, they actually tested conventional
filament type bulbs and concluded the life was significantly shortened
by how many times they are turned on and off. This only makes sense,
as each time you do it, you are taking the filament from cold to white
hot, which stresses it, just as any metal will be stressed by greatly
heating and cooling it repeatidly.

If you want more proof, here from the DOE:

http://www.eere.energy.gov/consumer/.../mytopic=12280

When to Turn Off Your Lights
The cost effectiveness of when to turn off lights depends on the type
of lights and the price of electricity. The type of light is important
for several reasons. All types of lights have a nominal or rated
operating life, which is the total number of hours that they will
provide a specified level or amount of light. However, the operating
life of all types of light bulbs is affected by how many times they are
turned on and off. The more often they are switched on and off, the
lower their operating life. The exact number of hours that switching
lights on and off reduces the total operating life depends on the type
of light and how many times it is switched on and off.



Only when incandescent lamps are near their normal
end-of-life does turning them on and off make a difference. That difference
is minor according to the research reports and amounts to only a few hours;
but it explains why lamps so often fail when turned on.

I'd be happy to see those research reports. And of course the extent
of the effect depends on how many times you turn it on and off. The
Mythbuster test was turning it on and off at least several times a
minute. It may be "minor", in the sense that the shortening of life is
way out weighed by the energy savings. Or that the typical light only
gets turned on and off a couple time a day. But that doesn;t change
the fact that incandescent bulb life is impacted by turning it on and
off, just like a CFL.



From the standpoint of cost, however, it's always better to turn a lamp off
if you don't need the light since the cost of energy to operate any lamp
designed for general lighting service is typically 80-90 percent of the cost
of providing light.

No one is arguing that it's cost effective to leave lights on. I'm
only saying that the more you turn them on and off, the shorter the
life.



TKM