CFLs Part 2 October 12, 2007
Posted by spacemom in : It ain't easy being green , trackbackYesterday, I was writing my post while dealing with the reschedule of the commanding for the spacecraft. I obviously left a few things ambiguous, so I wanted to address some of these items, as I had TWO!(2! I am so excited!) lighting people write!
First- The Hell part of the last post is how to buy a CFL. In the good old days, last year for example, I would walk into Target, grab a GE or Sylvania bulb based on its wattage. I would never buy a Target bulb because I knew the difference was that the Tungsten was thinner or the glass was thinner or the quality control wasn’t as good. The biggest difference between manufacturers was how long the bulb lasted. Ah- the Good Old Days.
Now, the challenge is to find the bulb that works with you. This is MUCH harder. I brought up the flicker because I am extremely sensitive to it. Over the weekend, we visited a "green open house" with a friend. This person was explaining how he made his home green, how much energy he was saving, etc. He was proud of the dimmable CFLs. Unfortunately for me, I can see the flicker of the dimmables. There were 7 people there when he lowered the current to the bulbs. 3 of us could see the flicker, including the home owner. Others couldn’t. The home owner said he found some other bulbs that were supposed to not flicker and we did try them. I still could see the flicker, but it was much less pronounced.
One of the lighting commenters made the following statement.
Andrew G. wrote:
Further to what Sharon has pointed out, the flickering is caused by a magnetic ballast. Most modern CFL’s have electronic ballasts, which eliminate the flickering.
Yes, CFLs have electronic ballasts. These control the current going to the bulb. Andrew, I agree 100% the electronic ballasts have REDUCED flicker, and for the majority of people, it does eliminate it. But it all comes down to FREQUENCY. Electronic ballasts control the current at a much higher frequency (ie, faster) than magnetic. Our eyes will generally not detect this if the frequency that the current changes is faster than our eyes report to our brain. Unfortunately, I am one of those said people who have a rather rapid reporting frequency. I still see the flicker. It is much different than the magnetic ballast lights at work.
In addition, the CFLs I am talking about have an integrated ballast. This means the ballast is in the light bulb (that big fat part at the bottom) and NOT in the fixture (like the tube ones in most office buildings. If I could afford it, I would seriously consider a non-integrated ballast system. These fixtures have the ballasts and not the bulbs. This allows for better dimming capability and less flicker. The are rather cost prohibitive for the home owner (unless you win the lottery).
Okay- Now that I’ve addressed flicker, let’s move onto the other two issues: Color temp and CRI. I’ll address color temps first:
Take a look at this great page that discusses color temperatures for photography. Take your time, review…You back? Okay! The sun is a 5200 Kelvin black body. But summer sunlight varies between 4900K and 5700K. Why? Simple, the amount of blue light reflected and scattered by the particles in the air. (why is the sky blue and sunsets red? the blue light from the sun is scattered and at sunset, the red light comes straight through our atmosphere while the blue is scattered away and at angles that are difficult to see–sorry digression)
The color temperature for a 100W tungsten bulb is about 2850K.
Take a look at THIS PLOT:
Andrew again points out:
For example, Sylvania’s Daylight CFLs have a color temperature of 3500 K, while most other lamps with a "daylight" label have color temperatures of at least 5000 K. Some vendors do not include the kelvin value on the package, but this is beginning to change now that the Energy Star Criteria for CFLs is expected to require such labeling in its 4.0 revision.
AH yes! Someone who really understands. But Andrew, I don’t want DAYLIGHT in my house, I WANT A TUNGSTEN BULB EQUIVALENT! (caps in a whiny voice). I really don’t want to have something as blue as daylight. I want the warm reds and yellows of the bulbs I grew up with. Jay went out and purchased the Sylvanias. I had to hunt and find in small lettering that the color temp was 3000K. On the GEs, I had to go on-line to find the color temp. I discovered that the GEs were 2700K. This is much closer to the tungstens and even a bit redder.
Sharon wrote
You have connected flicker with color temperature and CRI,
when it has to do with the ballast, not the lamp. And you compared apples to
oranges when it came to the Sylvania and GE lamps of different color temperatures.
The flicker issue was meant to be separate. My apologies for making it look like it was related.
However, I disagree when you say I am comparing apples and oranges with the Sylvania and GE lamps of different color temperatures. The packages say "Replaces a 100W bulb!" We get the lumens on the package. We discovered that the GE uses 26W and the Sylvania uses 23W (which is why Jay grabbed the Sylvania’s). Again in a whiny voice, how is the consumer supposed to know that these bulbs are different???? How? I looked up the color temps. I understand blackbody spectrums. What about the people without physics backgrounds? I know you are an engineer and have the education to stop and evaluate these things from more than the packaging, but the average consumer won’t. They don’t and they shouldn’t have to! These bulbs both claimed to replace a 100W bulb, and they both do, but completely differently.
I will avoid the whole subject of CRI today since even the experts disagree on this measure!
The upshot of the CFLs is this: GO for it people, but be aware that you may have to go through several tries to get the bulbs that work FOR YOU. We replaced 5 100 W bulbs with 5 26 W bulbs this week. I love the new bulbs and even find them a little too bright, but I LOVE the warmth and red spectrum I get.
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I use wikipeadia links to make it easier for the non-tech geeks out there!
Comments»
There is actually a lighting manufacturer that makes a good quality product that is not cost prohibitive: www.osram.com.
You also might want to do some research about the color of light as it effects depression. There’s been studies done on the theraputic affects of blue light on those suffering from depression. It’s possible that the light color you’re used to is actually not a healthy spectrum for you.
I know exactly what you mean about flickering and light color. I cannot handle the orange-colored lights for our living areas and the sodium vapor street lights make me so crazy we had to invest in very heavy no-light drapes for the bedroom. But when it comes to reading, I need the closest to sunlight spectrum in order to read without getting a headache. And I have spent years trying to explain the flicker phenomenon to hubby who just doesn’t see it! I even noticed our TV was going out 3 months before it gave up the ghost. Hubby did not believe me when I told him there was something wrong with the scan frequency and it was flickering!
Andrew’s comment on Osram is right, they do make a good value for money product. Try their Warm White Deluxe. They have a new bulbe out that is supposed to be better for dimming but I have not tried it yet. It’s a German company and is very common over here, but I don’t know about availability in the US (haven’t shopped for bulbs there in over 20 years!) Here we have Phillips as a big supplier and they have a whole range of bulbs with different color spectra. However, flicker is still a problem. (sigh) As Kermit said, “It’s not easy being green…!”
So glad you followed up with a second posting!
I do understand your frustration on the packaging and consumer side of selecting the lamp that works best for you. As an engineer and lighting designer, it is often frustrating for me to select the proper lamp for a commerical design application, even with all of the lamp information at my fingertips!
I have forwarded your blog posting to a good friend and technical expert at Osram-Sylvania (it’s the same company) and I hope that she can “shed some light” on this for you.
I think you should save yourself the anxiety and go back to regular ol’ light bulbs. I heard a program on our public radio that suggested the CFL bulbs are not all they are cracked up to be, environmentally speaking. Sounds like a whole lot of effort for not much green payback.