I was told that CFLs give off more heat than a corresponding wattage incandescent bulb. Is this true? I have some can lights I would like to switch over from incandescent because of the heat they generate. Is this not advisable?
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I was told that CFLs give off more heat than a corresponding wattage incandescent bulb. Is this true? I have some can lights I would like to switch over from incandescent because of the heat they generate. Is this not advisable?
Haven't seen the data on heat generation, but since you replace a higher wattage incandescent lamp with a CFL, you need to compare the heat generation to that of the lamp you are replacing.
For example, a 15W CFL may produce more heat than a 15W incandescent lamp, but it will be replacing a 60 watt incandescent.
Personally, And I know this will open a can of worms; I don't like edison base CFL's. They don't seem to be as bright as the incandescent lamps they replace, and they don't last as long as the manufacturers claim.
There is something about shrinking the ballast down small enough to get into a compact, screw base package that sacrifices light output and quality.
I like medium base CFLs, and I hate candelabra base ANYTHING.
I agree the ballasts in CFLs are les resilient, but they cost, what, $1 each?
I wouldn't worry about the heat. Worst case scenario the ballast overheats and the bulb does prematurely. Then you buy another.
This statement:
The fluorescent bulbs used in your home emit only around 30% of the heat of their equivalent incandescent bulb, making them far cooler.
Is an excerpt from:
49906 - Technical Specifications - GE Home Lighting Products
Heat from a CFL is rarely an issue.
I have had excellent luck with life and light output of CFL lamps, either screw in or plug in.
I have a CFL lamp in my range hood I leave on 24/7, nothing special, whatever the deal of the day is at the hardware store. I change it once a year when it burns out, so the published hours of operation is true.
Sure there are and always will be any lamp can burn out prematurely compared to published life, hours of operation published is an average of several thousand lamps tested.
The issue with amount of light from a CFL compared to a regular incandescent simply has to do with lumen output, always compare any CFL to the incandescent lamp it will replace.
However, most times the incorrect "color" lamp is chosen. This is a bit complicated to explain, I will do my best:
I find that the color temperature of a CFL chosen is often incorrect when replacing an incandescent lamp, which is 2700 Deg Kelvin, (AKA 27K). Most times people are not familiar with CT ratings, and buy any CFL. I see that most stores offer 41K or at best 35 K. Look for a CFL rated 27K to imitate a incandescent lamp.
Even a CFL lamp rated 27 K will not imitate a incandescent lamp exactly with the same color rendering, difficult to create a fluorescent lamp with the same color characteristics. What would imitate a incandescent lamp would need to be a CFL at 27 K with a Color Rendering Index of 1. This does not exist, most have a CRI of 82. Need to look for a CFL lamp with the highest CRI rating possible.
Learn About Light: Color Rendering: GE Commercial Lighting Products
The best I could find is the following link, click on Interactive Color Booth, a separate window will pop up, and you can chose different lamp sources and compare the color of any two:
Learn About Light: Selecting the Best Color Lamp: GE Commercial Lighting Products
If a 41K lamp, even if the proper wattage or light output is similar to the incandescent lamp is chosen, a 41K lamp with the will make an area seem dark, due to color temperature and CRI.
I hope I made some sense explaining this, and how important it is to use a warm color CFL with a high CRI rating when using in place if incandescent lamps. I use them thruout my home, and in many commercial applications where color and CRI is very important, and the results are fanastic. No one can tell there are no incandescent lamps.
I have no problem with F34 CW tubes, I have commercial fixtures in my kitchen and laundry room that reallly brighten the place up, or separately ballasted plug in 3500 K plug in base CFL "can lights" at work, but I still find the screw-in ones suck.
Just my opinion, and no "facts" will change it!
I'd like to add a couple of comments.
CFL's don't like cold weather. They are very dim until they warm up.
CFL's don't start instantaneously. I have one that takes about a minute to reach full brightness. This is a flood.
CFL's contain mercury. Less electricity, but requires hazardous waster disposal.
The color temperature and spectrum output make a lot of difference.
I'd like to add a couple of comments.
CFL's don't like cold weather. They are very dim until they warm up.
CFL's don't start instantaneously. I have one that takes about a minute to reach full brightness. This is a flood.
CFL's contain mercury. Less electricity, but requires hazardous waster disposal.
The color temperature and spectrum output make a lot of difference.
CFLs make the most sense where they will be switched on and left on for a while. They don't like being switched on and off every 5 minutes, that's an application for long life incandescents.
The CRI of a flluorescent is an important number to look at when buying any fluorescent bulb or tube. They rarely go above 90, (100 being sunlight). Even incandescent bulbs do not have a CRI of 100, they are too yellow. We like them because they give a warm illumination (good flesh tones) and they are what we compare everything else too, even if they are worse at color rendering.
For myself, I use 4100K fluorescent tubes because the ones I get have a CRI of 90 and give the most lumens per watt. The 2700K tubes are somewhere around 80 and have a noticeably lower lumen/watt ratio. If I have a 4 tube fixture, I put in two 4100K and two 3000K tubes (3000K tubes are cheaper than 2700K). People seem to really like that because it introduces more red into the light and makes it warmer. I get positive responses even from people that say they HATE fluorescent light. Of course it helps that when I do that it usually is when I am replacing the magnetic ballast and 4 year old T12 tubes with an electronic ballast and T8s. Tubes do go downhill with time.
EPM
The one in my range hood has been there since 2002, and I've never changed it.Quote:
Originally Posted by tkrussell
Since everyone is jumping in... I personally like the cfl's for fixtures that are very hard to reach, or in outdoor fixtures. Yes, they are dim when cold, but unless the weather is severely cold, the do come up to near 100% output. But when it comes to indoor use, I think there are much better ways to conserve than by switching to cfl's. First of all, use a lower wattage bulb, or use a dimmer. Cfl, despite what the manufacturers say give off a light that is more suitable for retail or office environments. A color corrected cfl is still nothing like the warmth of a incandescent lamp. With the use of computer controlled lighting, and the X-10 method of controlling lighting, anyone can dim any incandescent lamp, switch it remotely, and easily extend the life well past the life expectancy of the cfl's.
It's subjective.. . I hope they do not eliminate incandescents and halogens as there has been talk of doing.
Personally it depends on the room, the fixture, and other factors. I use halogens in my living room and hallway, fluorescents in my kitchen and bathroom, incadescents in my bedroom. My church is all halogen except for the offices.
I'll add, whenever I use a bulb that is not fluorescent, it's on a dimmer.
Dimming does save electricity, but there is a BIG gotcha there. An incandescent bulb that is dimmed to 50% lumen output still uses around 80% of the power of the bulb at full output. Think of a 60 watt bulb giving off about the same light as a 40 watt bulb but using 50 watts of power. Also the CRI goes into the toilet.Quote:
Originally Posted by Missouri Bound
I have measured some bulbs that use 1/3 of the full power rating when the dimmer is turned down to where the light is extinguished. Think a 60 watt bulb consuming 20 watts of electric and giving NO light. They are great heaters though. Look back at another post I did on this subject. I have much more detail there.
Use of lower wattage bulbs is the correct way to conserve electric. Dimmers should only be used for occasional mood lighting. No matter what you think, CFLs do give the most lumens per watt of electric in an edison base fixture. I will leave out all the problems of manufacture, loss of lifespan when switched on and off a lot, and disposal.
EPM
EPMILLER... "CRI"? How many homeowners care about the color rendering index of their lamps, especially incandescents? Your information on the lumen output vs actual power input is well taken. However most lower wattatge bulbs are more expensive than the standard wattage designation. If you have a 60 watt bulb, and dim it so it effectively puts out the light of a 40 watt bulb, you double the life of the bulb. Even if that costs you the equivalent of 50 watts, as you stated. I have approximately 8 fixtures that I control with X-10. Being able to lower or increase lighting levels to suit the event, whether as a night light, security lighting. Or any party situation is very suitable to me.
I will not disagree with you if your dimming capabilities suit your needs. I only wanted to alert people to the hidden down side of dimming. For myself, I am a tightwad and I use the lowest wattage bulb (most efficient) for the light level needed. I switch more fixtures on when I need more light. As to CRI, I must be an odd bird. I do take it into account. My wife does quilts and needs good lighting. Also, my eyes are starting to notice the fact that I'm not as young as I once was and good white light (4100K CFLs or halogens in specific fixtures) makes evening reading easier. A dimmed incandescent, especially on an older book with slightly yellowed pages doesn't work.Quote:
Originally Posted by Missouri Bound
Bulb cost also is not an issue for me. The basic GE or Sylvania 40 to 100 watt bulbs all cost about the same (approx 50 cents each). They seem to come out best in the MEASURED lumens per MEASURED watt tests that I did too. And the lower the wattage, the more efficient too. I only use two 25 watt bulbs in the house, those do cost more and they have lousy color rendition even at full brightness, but a short narrow white hall and small white closet don't matter.
Got to save my electric and shut this computer off. :D
EPM
EPM... thanks for the feedback... and as far as your wife's quilting goes, look into an "Ott" light. My wife uses one for her needlepoint. It's fluorescent, and I'm sure it's just a color corrected bulb. But as far as fine work and reading it is a great task light.
Yeah, that's a 6500K bulb. Has a lot of extra UV. Check the CRI though. They often aren't as good as a QUALITY 4100K tube. I won't pay the price for those things. Rather run two 4100K CFLs at less than half the price and longer life. Even better, one 4100K and one 3500K. The extra lumens and different source points do a real good job for my wife. Of course for your wife, the ease of movement of the fixture may well be important.Quote:
Originally Posted by Missouri Bound
One thing those Ott lights do is spread the light source out over a larger area than a more point source fixture. Diffusion works wonders at giving a feeling of good light. I actually am a fan of 4 foot tubes with cloud diffusers. Really reduces shadows and gives a more even light than several cans. WORKING lighting, not mood lighting!
An interesting note on those "daylight" tubes it that in situations of continuous use (think windowless office), you get faster fading of surface colors. Same thing that the sun does. But even 4100K bulbs bleach the labels inside the fixtures. Write the install date on a regular fluorescent tube (glass part) with a Sharpie. If used 12 hours a day, you won't be able to read it after a year or so.
EPM
CFL's give off 2/3 less heat than incandescent bulbs for they use 2/3 less power. The ceramic ballast on the bottom does get hot though (just like an incandescent bulb) so don't expect that to be cool.
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