If I have a fixture that is intended to be used with 3 60W bulbs, but
I want to get more lumens out of it, can I use 3 23W (100W equivalent)
energy-saving bulbs? Is this only limited by the wattage?
(the fixture is not fully-enclosed and is not controlled by a dimmer)
If I wanted to use a dimmer, could I just use analogous dimmable
Yes, you should get more light with the 100W equivalent bulbs; but, you
might find there is a delay of minutes before they come up to full
brightness. I am told that not all of them do this but the ones that I have
tried are annoying in this regard.
Dimmers are usually a no-no (I have heard of high efficiency bulbs that can
be dimmed with a special unit, but don't where to get them or anything else
personally, i don't understand this fascination with
the obsession some people have for brighter & brighter
lights. when is it going to stop ? when we have 1 mil
cp aircraft landing lights adapted into ceiling high
i have perfect 20/20 vision and am a former military
aviator. i find these 100 watt bulbs in hotel rooms to
be offensively obnoxious enough to impair my ability
to read things comfortably (as opposed to a lower cp
or lumen level).
i've witnessed people install high intensity halogen
lamps in bedroom spaces and find myself needing some
sunglasses when they're fully powered on.
am i the only one that feels this way ?
I have 20/10 vision (better than perfect?!) and like a lot of light when I
am reading or working.
If bright lights bother you, you might want to speak to a doctor; you
shouldn't ever need sunglasses indoors.
Yes, the watts rating is what the wiring can handle electrically and
what the fixture can handle thermally. A 20W CFL gets as hot as a 20W
incandescent (watts is watts is watts, if the CFL manufacturer is
honest and includes the wattage of the ballast).
I have a 150W equivalent (45W) CFL in a socket rated for a 100W
incandescent. Works great, wish I had more light though (it's in my
garage where I work on my cars).
Correct Tyle, the wattage rating for a fixture is really for
protecting the fixture and the wiring from overheating.
I've done a lot of fixture replacements in my life and you can always
tell when someone has been burning too high a wattage bulb in the
fixture because the wires in the ceiling box have insulation that
cracks and falls off. That's why the base of the fixture has
insulation. It's not really for keeping heat or cold from coming in
but to keep the wires in the electrical box from baking.
If you have a lampholder that is porcelain, that's much better then
the cheap paper lined brass lampholders.
I'd have to disagree. The whole point of CFLs is that they produce more
light out of the wattage. More light means less heat. The sum of the
power converted to light and the power converted to heat would equal
the wattage of the bulb.
I think we might actually agree. ;) Yes, CFLs make more light with
less heat and less wattage. So,
15W incandescent = 250 lumens
15W CFL (i.e., a 60W-equivalent) = 1,000 lumens
60W incandescent = 1,000 lumens
15W CFL (i.e., a 60W equivalent) = 1,000 lumens
With CFLs, you can either keep the wattage/heat the same and get more
light, or, keep the light the same and use fewer watts / produce less
... I think. :)
With CFLs, the wattage/heat is not the same. They produce more light
and less heat for a given wattage. That is specifically why they are
more efficient.Some of the light may be converted to heat when it
hits something, but that heat is not a problem for the fixture.
Ok, I stand corrected. I forgot that the energy that goes into making
light doesn't heat the lamp/fixture itself, but rather the walls/floor/
ceiling and people/pets/etc that it shines on. So from that
perspective, yes, a 15W CFL will have a lower surface temperature (by
about 15%, assuming 5% incandescent efficiency and 20% CFL efficiency)
than a 15W incandescent. You're still producing the same number of
BTUs (BTUs = Watt-hours x 3.414), just some of them are in a
roundabout way (important for HVAC calculations, but not for fixture
In any case, it's still safe to use a 23W (100W-equivalent) CFL in a
fixture rated for 60W. :)
add "corneas" & "retinas" of people that it shines on.
i wouldn't be surprised if years from now we
start reading more about people with vision problems
as a result of this obsession with more brighter &
(like the sun worshippers getting more skin cancer
and cataracts - albeit it's UV vs. IR, why risk it?
military IR jammer pods are labeled with eye hazard
warnings by the way).
You are correct of course, he should have said "a 20w cfl gets nearly as hot
as a 20w incandescent."
An incandenscent puts 98% of the electricity into heat; a CFL only makes 94%
I am not sure you could measure the difference, but it is there.
20/10 simply means you're far sighted, like me. I can read street
signs before my wife can see find them at all. But that measurement is
only for "visual acutity" or how fuzzy are things.
I am not aware of a measurement for brightness sensitivity. It is well
established the eye gradually needs more light past age 20. I have
notice that there is wide range of brightness preferances.
Futher complicating the issue is how the eye adapts to the overall
brightness when you move from dark to bright and back.
Richard Reid, LC
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