How long before LED's replace CFL's

I’ve been buying mine from Home Depot. The brand they carry is called n:vision and they have three different “color temperatures”. Here is a description of them on the n:vision website.

Their descriptions are pretty accurate, IMO. I particularly like the “bright white” CFL’s, especially in my kitchen and bathrooms. The colors of objects in this light look very clear and natural . They are very white, not blue, and not yellow. The “daylight” bulbs do have a kind of harsh, bluish tint to them, but they are very bright. I have one in my utility room and one in an outside lamp. The “soft white” ones are more yellow, like a lot of incandescents. I’ve got a couple in some table lamps, but I prefer the “bright whites” over them. I’ve had most of them for a couple of years (installed them when I moved into this house and none have gone out yet), but I can’t speak to their longevity beyond that.

I have to ask. How many LEDs does it take to replace a CFL light bulb?:slight_smile:

i have cfl burn out as well. i’m wondering if old wiring is a culprit. there are only about 5 outlets in the house that were wired from 1970 -now. the ceiling lights are mostly 1920’s wiring. (yes, it is a bit scary)

i try to go with cfls in the lights i leave on the most ie kitchen, bathroom, living room. incandescents in the lamps where i do the most reading/crafting.

I would warn people away from the CFLs at Costco. I bought two packages of the 65-watt flood lights, and a couple of them have burned out after less than six months. The ones that haven’t burned out take forever to warm up. The one in our bedroom is bright for a second when you turn it on, then it gets about as dim as a candle, then it slowly warms up over the next 5 minutes. The bulbs were about $15-20 for a pack of six, which is why I bought them instead of the $10 GE bulbs at Target. But now I wish I’d saved my money.

Edit: My house was built in the early 70s, so I don’t think wiring is a problem.

My newest are also n:vision and they come on very quick.

My Phillips decorative are very slow starters but get and stay very bright.

Commerical Electric appear to be the 7 year old exposed spirals that start very fast.

I’m not sure what you’re asking? An LED represents less than half the energy use of a CFL. As for how many of the little LED lights inside the bulb, that depends on the brightness. They come in a variety of light intensity. I have a flashlight with a single LED that is brighter than one with 20 of them. The problem is that they are made with a “back” to them so they only illuminate in one direction. This is usually coupled with a lens to focus the light. The bulb I looked at at Sam’s had a lot of the smaller LED’s with lenses at a 45" angle and they were arranged in a circle. They were 40 watt lights and were billed as outdoor or specialty lights. Without actually seeing them it is obvious that they produce light in a pinhole pattern that would resemble white Christmas lights on steroids. Kind of a mini chandelier. What I want is at least a 60 watt equivalent that uses a frosted bulb to disperse the light into an even pattern.

For incandescent lights, the main factor for burnout is the number of hours they are on. This is not the case with fluorescents.

With fluorescents, a much more important factor is the number of times the power is cycled. Every time you turn one of them on, a little bit of the electrode erodes away. But while they are on, the erosion is very minimal. So what you need to do to extend your CFL bulb lives is to train yourself not to turn them on and off multiple times a day. Either leave them on all the time or just turn them off only once or twice a day.

I just changed out one of the bulbs that burned out and I noticed something odd. It’s a floodlight, but it’s basically a glass floodlight shell that screws on to a regular light-bulb base with a twisty-type CFL bulb. There was a burned spot at the base of one of the twisty parts (you can tell I got my degree in electrical engineering) and there was a pungent odor. I wasn’t just poisoned with mercury, was I?

There is no need to go this extreme. It is a good idea not to flip them on and off 50 times a day but your recommendation is not needed.

Its a light, if you don’t need it, turn it off. At worst your bulb will last 6+ years instead of 7+ years. People are buying CFLs to save energy I assume. To leave the lights on to get a few hundred extra hours of life on the bulbs is not very sensible.

The master speaks in a related article: To save energy, should you turn lights off or leave them on?

Not likely. The burn spot was likely an electrical failure and the mercury vapor is still sealed in the twisty part which is also sealed in the lens part. And even if you broke it you didn’t snort it like cocaine. If you’re still worried than go down to the old folks home and ask how many of the 90 year old guys played with liquid mercury as a kid.

Magiver it was a rehash of the oldest joke since the invention of the light bulb. The smile was there to indicate that. I apologize for confusing you.

The next line:
I still don’t know. I’m in the dark waiting to find out.:slight_smile:

I don’t understand. Can LEDs be made with slightly yellowish glass which give a slightly yellow light? Or is there some intrinsic/ economic reason that it has to be blueish?

What you need to understand is: there are no white LEDs.
White light is produced by using a blue or UV LED die, and then covering it with a phosphor which emits a yellowish light. Often, the blue is incompletely absorbed, resulting in a blue cast. High-quality LEDs (like Luxeons) don’t have this problem.

Filtering will not work. The light from a LED is produced in a semiconductor junction, and has a narrow range of frequencies (unlike an incandescent bulb, which emits a full range of visible spectra). So (as beowulff noted) a “white” LED is often a blue LED, and a phosphor that absorbs blue light and emits yellow light is added. You cannot use a yellow filter, because there is no yellow in the LED light to start with (a yellow filter over a blue LED will not emit any light, just get warm).

You can use RGB LEDs to get white, but that is really expensive (ie three times the cost per LED). Better white LEDs have better phosphors and designs to get a less blue white. The future is probably white quantum dots excited by a blue or UV LED, or a UV LED exciting multiple phosphor layers, but these are less both efficient.

Si