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Back to the original post. I'm still gathering a supply of regular incandescents, now working on stocking 75w bulbs. But, in being willing to explore options have bought and installed some of the new halogen/CFL bulbs into table lamps in the family room which are on for long periods. I replaced 100w bulbs with 75w equivalents. Besides a slight drop in brightness, which was expected, I find the behavior of the new bulbs a bit weird. Initially they're bright, but I notice the halogen module turns off well before the CFL has come up to full brightness, and it seems like the room suddenly goes dim with the CFLs taking another 3-4 minutes to brighten. The color temp is slightly better than the other CFLs I've tried, but maybe because I chose the GE Reveal bulbs. I'm not thrilled with them, but will leave them in place for awhile to see what other family members think. These are rated at 20w total consumption, so I'm saving 160w. Personally I'm thinking I'd rather have the regular bulbs back.
I was all confuzzled when I went to buy light bulbs this weekend . All I could find were halogen bulbs. I got GE reveal 53 watt halogen, which are said to be the same as 75 watt incandescents. Are these just the "newer, more efficient" incandescents then? I didn't know what "halogen" referred to in terms of light bulbs, but I just went with it as the store had no old style 100 watts. Most importantly: is the color going to be the same on these? I want a CRI of 100 or very close; the boxes do not give that info.
Is LED the best alternative for good lighting? What is the typical CRI for these?
Do they make CFLs with high CRI now? The best CRI I've seen for them is around 80; that's just not good enough. Saving money is not as important to me as lighting which actually shows a full spectrum of color. The harshness of fluorescents is just unacceptable to my eye.
I find it interesting that you spend the money to super-insulate, put in HE heat pumps (I put in a geothermal heat pump... they are $$), and yet are willing to waste a lot of power on incandescents.
First, you need to choose the right color temperature to your liking. You have numerous to choose from. Second, (not sure when you bought your last CFL), but those in my outdoor lights start up almost instantly even when it is zero degrees outside. Third, for light efficiency, if incandescent has an efficiency of 1, a fluorescent has an efficiency of 4 times that, and an LED has an efficiency of 10 times that.
In my last house, I replaced 54 recessed lights with dimmable compact fluorescents and the R40 reflector shield and cover, for about $7 each. Power companies want people to use less energy, as they don't have to build a new power plant, so often they will subsidize the cost of the bulbs. My electric bill went down by over $50/month. Calculate the payback time. In the 14 years I lived there, I didn't replace more than 5 of them (the enclosed reflectors are hard on them, due to heat).
My current house is ultra-efficient. I don't have any incandescent bulbs, and I can light the place up like Fenway Park, and the color is extremely close to incandescent (because I picked the correct color temperature to my liking). (Though the lights outdoors are mercury vapor floods and are old-technology. I would use metal-halide now. I only turn these on when I plan to be outdoors for a while or am having a social event, as they are slow to turn on). Though only being here 2 years, have never touched a new bulb.
Though this is off the topic, you can build an ultra-efficient solar house, that doesn't look like one. My geothermal basically never runs, even when it is 10 degrees out. Secret: good southern light exposure, lots of thermal mass, lots of insulation, lots of glass with insulated shades that close at night...
g
I have water in 5-gallon containers (that are out of sight) in the attached greenhouse. Many hundreds of gallons. Also insulated concrete forms help quite a bit.
Insulated shades:
google "insulated window shades" and you will find dozens.
However, be advised that the color of visible light from a lamp does not always correlate to proper color rendition. The light we see directly may be adequately bright (lumens) and a pleasant color (temperature), but the reflected light off objects (rendition) may not be accurate. Most commonly with CFL and LED, this occurs when the light emitted from the source does not contain the appropriate range of wavelengths in the spectrum to reflect back the true color of the object, the source does not emit the appropriate frequency of wavelength with enough power (candelas) or in all directions equally, or that the emission is spiky which can make the color perception inconsistent.
Any one of these factors can also produce a perceptible flicker effect in sensitive people, with both CFL and LED, above and beyond the mechanical flicker of the older fluorescent ballasts.
ETA: example how color works... "white" light is comprised of many wavelengths, an object that appears "green" to our eye actually absorbs most of the waves that are not in the "green" frequency, leaving only the waves in the "green" frequency to reflect back to our eye. If some or all of the "green" frequency wavelengths are missing from the source light or are weakly transmitted, the object cannot reflect back "green" and will appear black/gray/muted/muddled.
Last edited by MissingAll4Seasons; 02-25-2012 at 04:08 PM..
Reason: adding note on color theory
And let's chat a little about efficacy and efficiency, and how those two stats may be completely irrelevant to the actual usefulness of the lamp in question...
Quote:
Luminous Efficacy is a measure of how well a light source produces visible light. It is the ratio of luminous flux (the perceived power or "brightness") to power. Depending on context, the power can be either the radiant flux (total electromagnetic radiation) of the source's output, or it can be the total electric power consumed by the source.
I emphasize the "or" because sometimes "efficiency" comparisons are not made luminous:luminous or radiant:radiant which can make one (inaccurately) appear better or worse than another.
Quote:
Not all wavelengths of light are equally visible, or equally effective at stimulating human vision, due to the spectral sensitivity of the human eye; radiation in the infrared and ultraviolet parts of the spectrum is useless for illumination. The overall luminous efficacy of a source is the product of how well it converts energy to electromagnetic radiation, and how well the emitted radiation is detected by the human eye (expressed in lumens per watt, or lm/W).
Note that we're just talking about the amount of visible light produced, not the color temperature, color rendition or overall usefulness/appropriateness of emitted wavelengths.
Luminous efficiency is the ratio of luminous flux to radiant flux expressed as a percentage or as luminous coefficient.
Quote:
The luminous coefficient is luminous efficiency expressed as a value between zero and one, with one corresponding to an efficacy of 683 lm/W.
Why 683 lm/W? Because this corresponds to the maximum amount of light perceived by the typical human eye -- which is naturally attenuated to perceive wavelength 555nm (green). So every watt of power used by the solid green light source produces the maximum radiant flux and the maximum luminous flux (i.e. 100% "efficient").
HOWEVER, how useful is a solid green light producing only 555nm waves, even if it did only sip electricity? It might be bright as all get out, but everything white will appear green and everything that is any other color will appear varying shades of greenish-gray or black (no other wavelengths = no other colors).
So, most of the honest comparison charts between sources are only showing you the amount of visible light produced per watt and how efficient the source converts electrical power into radiation that is visible light for humans. For SOLELY illumination purposes, these numbers are useful. But for determining the usefulness of the illumination produced -- the color temperature, the color rendition, and the wave directionality and candela of each wavelength -- they mean nothing.
You, the consumer, must still determine what you need the light for, what features of the light are required, and how much electricity you need/can afford to spend to produce the lumens required. This is often why many of us who are not solely interested in the highest lm/W will advocate using multiple different light sources for different tasks based on which they are inherently better suited to fulfill.
For instance, a fluorescent T8 tube with electronic ballast and a "White" SON high pressure sodium gas discharge lamp have similar efficacy (80 lm/W) and efficiency (12%) ratings. Now let's look at the color correlated temperature (CCT) and the color rendering index (CRI) of each, as compared to tungsten incandescent lamps (14 lm/W, 2% efficiency).
The T8 ("warm white") has CCT of 2940 K, and CRI of 51 (Halophosphate) or 73 (Tri-phosphor)
The "White" SON has CCT around 2700 K, and CRI of 85
(note that typical HPS/SON have CCT of 2100 and CRI of only 24)
The tungsten incandescent has CCT between 2700–3300 K, and CRI of 100
The ceramic metal halide has the nearest true color render to incandescent at CRI 96, however the CCT is 5400 K which is way too cool/blue for most people; but has slightly better efficacy (65 lm/W) and efficiency (9.5%) than the comparable "cool white" CFL with magnetic ballist which is 60 lm/W, 8% efficient (tri-phosphor with CCT of 4080 K and CRI of 89; or halophosphate with CCT of 6430 K and CRI of 76).
Note that all household fluorescent lamps with magnetic ballasts (like the CFL) are 60 lm/W regardless of which gas they use to produce the various CCT and CRI.
My current house is ultra-efficient. I don't have any incandescent bulbs, and I can light the place up like Fenway Park, and the color is extremely close to incandescent (because I picked the correct color temperature to my liking).
Oh really???
Wow, just wandered across this thread (I've been known to poke my head in here every now and again), interesting statement there SS
Here's a posting you made Feb 4th this year in SS&P.
Quote:
Originally Posted by SuperSparkle928
Quote:
Originally Posted by Clark Park
My complaint has more to do with the small "flame" shaped bulbs I use in my crystal chandelier. Only incandescent bulbs produce the proper "glow" to make the crystal pendants "sparkle". Now, that is a bulb I'll have to start stock piling!!!
I absolutely agree with the 'flame' shaped bulbs statement. I have a case of them in the basement. This takes a lot of them:
(Finding a 1.5kW dimmer that fits in a normal wall box wasn't that easy, either).
Hmm... some discrepancy here, You don't have any incandescents, but you agree that the only way to get a proper glow from crystal pendants is from incandescents, and you have a case in the basement... Of course I know, you've chosen to change your position in the last 3 months, and accepted incandescents back into your life... Oh, but wait, didn't you say...
Quote:
Originally Posted by SuperSparkle928
Back to the topic:
1). I am not stocking up, for all the reasons listed above
2). Factors for making a choice: CFL or LED
3). They should ban incandescents. Geez, even my car has gas-discharge lighting
Wow that's a little creepy stalkerish, actually; inconsistent statement or not.
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. All I could find were halogen bulbs. I got GE reveal 53 watt halogen, which are said to be the same as 75 watt incandescents. Are these just the "newer, more efficient" incandescents then? I didn't know what "halogen" referred to in terms of light bulbs, but I just went with it as the store had no old style 100 watts. Most importantly: is the color going to be the same on these? I want a CRI of 100 or very close; the boxes do not give that info.
