I highly recommend CFLs for many reasons -- long life, cool operation
and significant energy savings -- but I'll be the first to admit the
quality of light, albeit good, just isn't the same. In terms of
colour rendering and overall appearance, it's pretty hard to beat
I think my primary problem with CFLs is that the light is, by nature,
very diffuse, similar to that of a "soft white" incandescent and I
prefer the "pop" and "sparkle" of a clear (as opposed to frosted or
coated) incandescent. But as in most things in life, there are
trade-offs and this is no different. And, as a rule, we humans are
pretty adaptable, so while our initial reaction may not be totally
positive, after a few days any shortcomings are largely forgotten.
So my advice would be to stick with a good name brand and pay close
attention to the product label. I find a 3,000K colour temperature
works best for me (2,700K is a little "too warm" for my liking and
anything above 3,500K is simply "too cold"). Look for a high CRI
rating (colour rendering index). Most CFLs fall in the range of 82,
but some of the cheaper, off-brands come in much lower (they use
older, less expensive "halo" phosphors); avoid them altogether. A few
have CRIs of 84, 85 or 86, and I'll gladly pay extra for these
products because I consider it worthwhile.
I would beware that CRI claimed slightly higher than 82 I would consider
likely to be dependent on "same active ingredients" as T8 fluorescent
lamps that have achieved same color rendering index.
The difference - the narrower tubing enhances the mechanisms that
produce the spiky mercury spectrum and to a slight extent supresses the
phosphor output due to supressing the shortwave UV wavelengths of mercury
best-favored by tubing 1 to 1.5 inches in diameter.
Bottom line - if claimed color rendering index of a compact fluorescent
exceeds 82 but does not exceed 86, I would discount to 82 until I see a
spectrum giving evidence otherwise.
If claimed color rendering index is so high as to be more like 90-plus,
then I give some chance of truth - especially if the lumens are on the
low side - that allows "broad spectrum" to compute, although my experience
is that this is usually not the story, not even in a majority of cases
when "full spectrum" is claimed of compact fluorescents.
But I surely like most fluorescent lighting with color rendering index
of 82, since the color distortions of triphosphor fluorescent with CRI in
the low-mid 80's tend to be mostly in the direction of "colors more
vivid". CRI of 90-plus I have found to have mostly color distortions in
the opposite direction (duller especially with reds, pinks, oranges and
greens) even though milder than with old-tech fluorescents distorting in
that bad direction and worse with CRI often 62 or 53!
- Don Klipstein ( firstname.lastname@example.org)
You are one of the most knowledgeable people I know in the area of
lighting and I've probably gained more useful information from reading
your posts than any other source (and from those of Victor too).
However, you did say one thing that puzzles me.... if I understood
this correctly, in one of the messages related to this thread, you
said there are no Energy Star rated CFLs with a 3,500K or higher
I bought twelve 3,500K 23 watt PAR38 CFLs for my kitchen and although
I have long since disposed of the packaging, I was certain they were,
in fact, Energy Star certified. I just checked the manufacturer's web
site (Standard Pro) and I do see the Energy Star logo is clearly
printed on the product literature and on the picture of the lamp
This logo is also shown on their 4,100K and 5,000K variants (I believe
all are rebranded MaxLite products).
BTW, I selected this product because the stated CRI is 85 and because
they have a flat, hard glass lense identical to that of a standard
halogen PAR (as opposed to the soft glass or plastic construction of
most CFL floods). I'm very pleased with this product, although I
swear the colour temperature is higher ... 4,100K, if not more.
During the heating season, I use 100 watt halogen HIR PAR38s, but
during the off-months (April through September), I switch over to
these CFLs and save a total of 924 watts.
This is by the manufacturer, and since I see the "Energy Star" logo on
that page my asumption is that some of their products meet the "Energy
Star standard" and they want you to think that all do.
Looks like I might need to get corrected here - I checked this out and
(split into two lines)
If the color temperature (more correctly "correlated color
temperature") is outside the range of 2700-3000, then the
product/packaging must make a statement of color temperature and of color
and intended use, and I see spirit even if not letter in that rule that
such statements need to make it clear that the color is "not a usual CFL
color" (my words) and should make clear what the color is as best
understandable by consumers.
It appears to me that acceptable is "4100K Cool White" or "5000K Cool
Daylight Color" or "5000K pure white cool color" or "6500K Cool Daylight
Color" or "3500K warm white but more white" and the like.
I suspect the color of the bare bulb in free air at 25 degrees C without
the PAR around it may be closer to 3500, and in a hotter environment there
is more mercury vapor in the tubing and you get a color shift. I wonder
if the manufacturer's marketing department is even aware of this color shift.
OK, glad to hear that is, in fact, the case. I just examined one of
the bulbs and can confirm the Energy Star logo is printed on the base
and I'm almost certain it is also printed on the outer packaging.
When the bulbs are first turned on, the colour is a warm pinkish tone,
but within a minute or so, it is considerably cooler; to my eyes, it
appears to be 4,100 K.
I bought nine more of their 3,000 K CFLs for other parts of my home
(office, upper hallway and master bedroom). Compared to the 4 ft. GE
SPX30 tubes that are next to these lamps, I would say the colour is in
the range of 3,500 K.
I'm guessing there might have been a mix-up in the packaging but, as
you say, it could also be related to the operating temperature.
It's interesting to compare these CFLs to the Philips MasterColour
self-ballasted ceramic metal halide PAR38 lamp. The Philips lamp has
a colour temperature of 3,000 K and a CRI of 87. Side-by-side, you
can clearly see it is much richer in the reds and purples. I
***really*** like this lamp a lot, but I'm afraid the price is out of
my league (this one was kindly "loaned" to me last summer by a local
supplier who has always taken very good care of me).
On Tue, 11 Apr 2006 06:19:35 +0000 (UTC), email@example.com (Don
Heat output is only reduced by a factor of 4 and that I find to be a bit
on the optimistic side - not a factor of 10!
Oh yes, the light produced in a home mostly does become heat in the
home! Figure mostly 97 to 99.99 percent of electrical energy going into a
lightbulb becoming heat materializing in the home! Compact fluorescents
are only 20 to optimistically 25% efficient at producing light, although
with a spectrum favorable to human photopic vision and can be 4 times more
efficacious that way than incandescents (5-7% efficient and with a
somewhat less luminously-efficacious spectrum) - but that means 75-80%
efficient as heaters in addition to the light that does not make it out
I surely see the good points of compact fluorescents, but I also see a
lot of resistance to them with a significant portion of that resistance
due to failure to meet some exaggerated claims!
I surely see that the truth and nothing more optimistic than the truth
is good enough to sell compact fluorescents! Customers that are not
disappointed will be repeat customers and pass on good word of mouth!
I surely think that sales of 23 watt compact fluorescents will increase
if they are advertised as meeting/exceeding 75 watt incandescent and 100
watt extended-life incandescent as opposed to being often found half a
step short of the 1710-or-so lumens of a "usual" 100 watt incandescent!
- Don Klipstein ( firstname.lastname@example.org)
the nominal 1710 of 100W incandescent and their 25W Mini CF is rated
for 1800 initial lumens.
I am picking the 15W for SIZE. i have fixtures that I want to put a
brighter lamp into, but lamp length cannot exceed 5 inches.
But even in incandescents, there is lots of variance in light output
between brands, and models of the same manufacturer. Buyer beware, read
the labels CAREFULLY!! Most of us only pay attention to the wattage
rating when we need to be looking at Light Output!!!
The "A19" bulbs - the "usual size" 25, 40, 60, 75 and 100 watt ones -
are made in much higher volume on full-time dedicated highly automated
high volume production lines.
Did you ever notice that these sizes not only cost less than higher
wattage bulbs of that basic shape, but also cost less than 15 watt ones of
that basic shape and 7.5 watt ones of the same base size? Or that 4-foot
fluorescents (32 watt T8 as well as 34 and 40 watt T12) cost less than
ones of any other size?
And, 25-100 watt ones sell from shelf space that has a higher turnover -
lower cost related to square footage of space to be displayed on - not
even counting that 150 watt ones not only sell more slowly at any price,
but also take up more display space. But I don't think this is as big a
reason as that they don't get made by a highly automated high volume
production line that works full time and makes a truckload of packaged
lightbulbs with man-hours perhaps few enough to count on one hand!
If you want an idea as to how automated the manufacturing and packaging
is: Look at the packages for countries of manufacture! 25-100 watt A10
lightbulbs of "Big 3" brands as well as supermarket store brands of same
hour life expectancy and same lumen light output are made in the USA and
Canada! 4-foot fluorescents are made in USA, Canada and Europe! 7.5 watt
G10 lightbulbs and 7 and 4 watt C7 nightlight bulbs are made in China, but
Sylvania 100 watt lightbulbs selling at Lowes for 50 or 95 cents per
4-pack are made in USA!
- Don Klipstein ( email@example.com)
Bought an el cheapo LoA 64K at walmart today just to try it out for a
couple of days before making my decision.
Initial reaction is favorable.
While in this relatively new Walmart today, noticed they are using 5K T8
4 foot lamps over the open refrigerated foods area, and the high lamps
appeared to be the same. Difficult to get close enough to the lamps to
read the label accurately, but I can almost swear that I could see
5000K. It was a GE lamp.
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