CFL Bulbs

[Glen Miyashiro]

Re: CFL Bulbs

"Daylight" is a lot bluer than we think... and night-time indoor lighting is a lot redder. Millennia of campfires, hearths, candles, and oil lamps have conditioned us to expect that artificial lighting should be the color of fire. It's actually pretty amazing that the human eye can function over such a huge range of brightness.

Another issue is that CFLs, like regular fluorescents (and neon tubes, too) don't actually emit full-spectrum black-body radiation the way the sun, or a fire, or an incandescent bulb, does -- the phosphors that emit the light only do so at certain frequencies -- so the "color temperature" label on a CFL package is a little misleading. The CFL manufacturers try to blend their phosphors to approximate a full spectrum, but it's not perfect. See the differences?:

[Glen Miyashiro]

Re: CFL Bulbs

It's true that CFLs aren't usable for all lighting needs. I suspect that they're actually an intermediate technology, and that in the long run we'll be using LEDs for most everything instead...

...except for Easy-Bake Ovens. There are some things that really do need an incandescent bulb.

[Karen]

Re: CFL Bulbs

Scrivener, Glen, I have read in more than one place in the last six or less mos. that it IS a safety hazard, the using them in three-way. Who to believe? I've googled and read at electrical contracting companies, public service type sites, and websites of that nature. Who to believe? why take chances when multiple sources warn about doing/not doing so and CFLs have a three-way/dimmer version? I'm guessing we won't know how common or likely the hazard is to trigger until the majority of the population has used them for a time. They're just catching on.

Here's a vidoe production website about the CFLs...

http://www.execulink.com/~impact/fluorescent_lights.htm

Here Long Island Power company says... "Usage
While some CFLs can be used on dimming circuits, others should only be used with basic on/off switches. If you attempt to use a standard CFL bulb with a dimming control, you will shorten the product life and create a potential fire hazard."

Link right here....

http://www.lipower.org/cei/lighting_cfl.html

[glossyp]

Re: CFL Bulbs

I'm doomed. I used to play with it. Rolled it into pretty little balls and that kind of stuff. And <wince> I'm <twitch> perfectly <spaz> normal. I donno. There might be some hazard associated with it, but I have to wonder of much of a real threat it presents. After all, those who do all the warning stand to gain by making a bigger deal of it. </rant>

I hear you and it does seem like the government is just setting us up for additional taxes to pay for disposal.

What about oven lights? CFLs in the refrigerator too? Not to mention the appliances (motion detectors) that won't work with CFLs. I know it has been talked about, but I don't think a ban would fly.

That's what everybody said about banning cigarette smoking 20-30 years ago and look where we're at now. Watch what California does and that will show the future.

[GeckoGeek]

Re: CFL Bulbs

There's nothing so inherently safe that buying a cheap, unrated or falsely rated device can't possibly create harm. I don't think CFLs are uniquely dangerous.

[mapen]

Re: CFL Bulbs

Regarding CFLs in enclosed fixtures, I've got a couple in my kitchen in an enclosure, and this thread got me worried. I found the follwing on GE's web site:

Can I use a compact fluorescent light bulb in an enclosed light fixture?
Compact fluorescent light bulbs may generally be used in enclosed fixtures as long as the enclosed fixture is not recessed. Totally enclosed recessed fixtures (for example, a ceiling can light with a cover over the bulb) create temperatures that are too high to allow the use of a compact fluorescent bulb.

http://www.gelighting.com/na/home_li...t.htm#enclosed

[craigwatanabe]

Re: CFL Bulbs

Most ceiling cans (recessed lighting) have vent holes to allow heat to rise up and out of the fixtures. The issue with outdoor cans is that the they need to have covers over them to keep the weather out. That said there are still vent holes at the other end to allow heat to escape.

Yes heat can shorten the life of CFL's but compared to the length of time they will be shortened in regards to their overall longevity, minute per minute they will still save on energy for every instance they're on.

When CFL's first came out they were longer or wider prohibiting their use in some fixtures. Size is what limited their use. Today's CFL's are compact as the name implies and range in size from small candallabra to appliance to standard bulb and larger sizes. Size is the reason why some CFL's aren't acceptable in some fixtures like any light bulb.

When installing them in appliances yes it's not a good idea to put them in ranges or refrigerators due to the temperature extremes. However for range hoods they're perfectly fine. But some appliances use bulbs to illuminate the control panels and use 120v bulbs in electrical appliances that are wired for 240v. In this case the bulb voltage is lower however low in comparison to 240v. The lower voltage is 120v making their use in this case acceptable.

Like any bulb frequent switching on and off will shorten the life of that bulb. In motion detectors, there are no variable voltages. It's either on or off. If you set the motion detector to stay on for five or ten minutes their lifespan won't be affected too much or at all. I have CFL's in all of my outdoor motion detectors for four years now and none are failing.

Same goes for three way fixtures. I haven't had any problems with them in any of my three way lamps that use them. If the bulb doesn't come on there is no voltage going to it so there is no fire hazard. A standard
incandescent bulb will react the same way in a three-way fixture. It will not glow dimly so there isn't any transferance of voltage on the lower settings, the circuit simply won't complete.

[oceanpacific]

Re: CFL Bulbs

Regarding CFLs in enclosed fixtures, I've got a couple in my kitchen in an enclosure, and this thread got me worried. I found the follwing on GE's web site:

Can I use a compact fluorescent light bulb in an enclosed light fixture?
Compact fluorescent light bulbs may generally be used in enclosed fixtures as long as the enclosed fixture is not recessed. Totally enclosed recessed fixtures (for example, a ceiling can light with a cover over the bulb) create temperatures that are too high to allow the use of a compact fluorescent bulb.

http://www.gelighting.com/na/home_li...t.htm#enclosed

The longevity of CFLs in my recessed ceiling fixtures has been disappointing. Plus, the lighting level has been relatively dimmer. So, it's back to the regular fixtures for us for both cost and performance.

OTOH, I have some rooms with regular fluorescents (48" tubes) which have lasted for over a decade!

[Random]

Re: CFL Bulbs

Query: I got a light socket that accept 60-watt incandescant bulb.

Instead of a 15-watt CFL, can I put a 25-watt CFL in that socket? I mean, I'm not going over the 60-watt limit.

[Glen Miyashiro]

Re: CFL Bulbs

Query: I got a light socket that accept 60-watt incandescant bulb.

Instead of a 15-watt CFL, can I put a 25-watt CFL in that socket? I mean, I'm not going over the 60-watt limit.

Yes. You can, in that it won't draw more current than the fixture is designed for. Whether you want to depends on how bright you want your light to be in that room.

[GeckoGeek]

Re: CFL Bulbs

The longevity of CFLs in my recessed ceiling fixtures has been disappointing. Plus, the lighting level has been relatively dimmer.

You might want to try another brand. There is a lot of variability between brands and models. I don't know if it's still true, but at one point I saw a CFL that the fine print said was not to be run upside down. They were only usable in floor and table lamps.

For light output, compare the lumans not just the "equivalent to" on the front as I remember one that was a little optimistic in that department.

Bottom line: when buying a CFL, read EVERYTHING on the package.

[GeckoGeek]

Re: CFL Bulbs

Same goes for three way fixtures. I haven't had any problems with them in any of my three way lamps that use them. If the bulb doesn't come on there is no voltage going to it so there is no fire hazard.

I think the claim is that some CFLs have a non-standard base that will short out in a 3-way socket. I think it's worth checking before use to make sure that's not a problem.

[Random]

Re: CFL Bulbs

Yes. You can, in that it won't draw more current than the fixture is designed for. Whether you want to depends on how bright you want your light to be in that room.

Well, I want it to be brighter than a 60-watt incandescent. I know 15-watt is the equivalent, but I want more without shorting out the socket.

[Karen]

Re: CFL Bulbs

I don't know how you can get a 25 CFL to be as bright, much less "brighter" than a 60 incandescent. I still am not pleased with the CFLs brightness of light. Yes, they are better than past years but not quite perfect, however, our house does have a good number of them, now.

Since there are three-way as well as non three-way CFLs, I think we'd be foolish to take chances with them. Just because some people haven 't had problems "yet" doesn't mean they are safe, and with so many websites clearly stating they can be a hazard when not put in the proper fixture, I personally choose to err on the caustious side. Meanwhile, they use less energy and you bet I'm slowly starting to use as many of them as I can.

[acousticlady]

Re: CFL Bulbs

"Daylight" is a lot bluer than we think... and night-time indoor lighting is a lot redder. Millennia of campfires, hearths, candles, and oil lamps have conditioned us to expect that artificial lighting should be the color of fire. It's actually pretty amazing that the human eye can function over such a huge range of brightness.

Another issue is that CFLs, like regular fluorescents (and neon tubes, too) don't actually emit full-spectrum black-body radiation the way the sun, or a fire, or an incandescent bulb, does -- the phosphors that emit the light only do so at certain frequencies -- so the "color temperature" label on a CFL package is a little misleading. The CFL manufacturers try to blend their phosphors to approximate a full spectrum, but it's not perfect. See the differences?:

Alright, I have to jump in here and clarify a few things. For one, "daylight" at 5500K refers to the temperature of the emitting body (in this case the sun) which is saying that the elements emitting the light are doing so when they are heated to a temp of 5500K. Daylight is primarily in the yellow range (look at the sun - no wait - not directly ) Now, look at the chart above...... the wavelengths refered to are the colors we percieve. 400nm - about 450 nm, we percieve blue light. Notice that the daylight line drops significantly at that end. It is peaking in the 500 nm - 550 nm range where we percieve yellow and is still quite high at the upper range of 600 - 700 nm which is red.

Our eyes have only 3 color cones - 1 for blue photons (short), 1 for green (intermediate) and 1 for red (long). EVERY color we percieve is some combination of those. We percieve white light when all three cones types are excited (by incoming photons striking the cones and causing them to vibrate) equally. So, when sunlight enters our eye, it primarily excites the red and green cones and we percieve yellow light. Add in the little bit of blue that is present and we percieve a whitish yellow. (aside - yellow is the ONLY color in the spectrum that is its own wavelength (about 575 nm) and percieved through a combination of red and green).

Now, the "new" lights........ the white light that they are trying to mimic are based on the structure of the eye which is actually very hard to do. The T 12's that are used in the chart are utilizing blue and green primarily. This is because they use mercury. When mercury atoms are excited they emit photons of those specific wavelengths (quantum mechanics ). Which is why you see sharp peaks on that graph. When you look at pure mercury light it appears very blue. To counteract that, CFLs coat the inside of the tubes with phosphorus. As the mercury atoms bang against the phosphorus, the phosphorus glows white (through a slightly different process).

Now this should probably go under pet peeves, but...... neon tubes (or lights) will ONLY emit bright red light for the same reason mercury will only emit blue. Hydrogen tubes will emit a magenta color, Helium a peachy color, oxygen a pale blue and so on. Every element has it's own unique fingerprint of wavelengths it will emit. So the next time you hear someone talk about the neon lights on Broadway, tell 'em if it ain't red, it ain't neon!

And lastly, they are working very hard to produce LEDs that will emit (collectively) white light. They have successfully produced red and blue but green is giving them a hard time. (I know the guys who are working on this.)