LED house lights getting cheaper

[Donald]

Like many I installed CFL lights in many areas of my house several years ago, but was not able to find CFL bulbs that dimmed (smallish ones) for my many ceiling fans and small candelabra bulbs for some ceiling lights. I found the small LED ceiling lights at Walmart and some LED lights (that dim) for the ceiling fans at HomeDepot. Not cheap, but they will last a long long time. In MA is seems the power company is providing an incentive to HomeDepot to discount them more than normal. I live in NY but often shop in MA, so that works for me.

So a ceiling fan that use to have 4x60 watt bulbs now has 4x8 watt LEDs.

I am less concerned with turning the LED lights off than I was with incandescent.

I am seeing the "retail space" at HD now maybe 50/50 split with LCD vs CFL.

 

[greenjp]

You have to be careful when buying LED lights. There are a lot of performance claims made by some of the people selling them that do not stand up to scrutiny. They're getting a hard push right now because the profit margins on CFLs have been driven down.

In independent testing by the Department of Energy, a great many LED bulbs & lamps either 1) don't produce as much light as conventional bulbs, 2) have the wrong color temperatures, and/or 3) do not meet advertised equivalency claims. On top of that, the advertised lifetimes are frequently extremely optimistic. Only a couple of months ago did the lighting industry settle on a procedure for estimating LED lifespan and yet for years companies have been advertising stuff like 100,000 hour life with little information to back it up.

At a bare minimum, make sure whatever you're buying has a real "Lighting Facts" label (I say real because in true capitalist fashion some companies will put a label that sorta looks like this on their boxes without actually having gone through the process of getting their product approved) and/or the Energy Star label. Each of those require the company to submit their product for independent testing. So they don't guarantee that a product is good (same way a Nutrition Facts label doesn't mean something is healthy) but they are good indicators that 1) the company is willing to be honest about what they're selling, and 2) the information is accurate.

jeff

 

[Cujet]

I have a number of high end LED flashlights. They have a very limited lifespan. Regardless of the claims made by the manufacturer, they always fail to maintain full brightness after significant use (say 6 months).

I can't imagine the home based LED's are any better. As they typically use the very same emitters. Cree Q5's.

However, on our corporate jet, the cabin lighting is Nichia LED, and they are quite underdriven. They don't change color over time and they maintain proper brightness. I've replaced a few and they always match the old ones.

 

[suspiciousmind]

100,000 hours is about eleven and a half years. I don't know how lifespan could be calculated without testing them for about that amount of time.

Lots of different environmental changes are going to be dealt with over this long timeframe too which will affect lifespan.

 

[SuperDave456]

Bought our house 3 years ago. I replaced almost everything with CFB's, and put all the regular incandescent bulbs in shoe boxes on my shelves in the garage.
Most of the lights we use for a few minutes at a time. The lights we leave on all night, like on the front/back porch and a couple night lights, have lasted all 3 years. The lights that we have in the bathrooms, that get turned off and on a lot, have started to burn out.
I've started to just use the incandescent bulbs that I took down when I put the CFB's up. I figure that it is best just to use them up.
However, I find it interesting that something in the bulbs, if it is their internal ballast or something else, does not like the on-off cycle.

I figure that the LED's are much like the CFB's in that their "Lasts X-times longer" claim is just marketing.

I too am interested in buying a bulb that I will pass down to my grandchildren. However, I doubt anyone is interested in engineering and manufacturing such a bulb. More money is to be made with cheap goods and a large marketing department.

I'm hoping that by the time I burn through all the bulbs that I have that all the bulb makers will have ironed out all the kinks in their bulbs.

 

[Smokescreen]

All I know is that loads of truckers rigs and trailers have LED tails & have many LEDs that are not working. Either they don't work well in that environment or the 25,000 hour+ lifespan is vastly over rated.

I do think they work great in well built flashlights though...and that will be my extent of use with them until they are the same $ as CFLs or lower.

CFLs will have significantly shorter life in the colder temperatures and in high on/off cycle applications. In these situations, the good old incandescent is still the most reliable and least expensive total cost of ownership, especially when you can get them for 10-20c a bulb.

 

[The_Jeff]

I'm not seeing a lumens advantage over CFLs yet.

One forgets how subsidized the low-output CFLs are until they go buy a "big mother" one for $12. I have a 65 watter, light out put of 300 watts, in the light over my dining room table now. Is a cure for seasonal depression.

Check out the Color Response Index, an incandescent should be 100; a lousy flourescent 65. Both CFLs and LEDs should have CRI ratings. I enjoy eating under a good one; the colors "pop" on my lettuce and tomato in my salad. There are many lousy CFLs from five or eight years ago still in service in my house, they haven't burnt out yet, but the replacements look better. Don't forget to dust them too, helps more light get through.

I managed to find a 1.5 watt candelabra CFL a few years back; even came with an adaptor base. Can't find anything that low wattage anymore. Make great "leave on all the time" lights.

 

[PandaBear]

In theory, LED last longer than CFL, but not in practice for the white LED that converts UV or blue to white. It also loss a lot of the lights to heat and the diode housing, so in reality their efficiency is nowhere close to its theoretical limit.

Also, the life of LED has a lot to do with the amount of heat it gets and how much current you run in it. If you run the current low enough, it does last forever (although for white LED the florescent material that convert UV to white may die, and leave you with a UV light).

The power circuitry with cheap Chinese capacitors on the other hand may die way before any of these wear out.

 

[Samilcar]

Originally Posted By: suspiciousmind
100,000 hours is about eleven and a half years. I don't know how lifespan could be calculated without testing them for about that amount of time.


Average lamp lifespan is usually defined as the point when 50% of a group of test lamps fail and 50% still work. So you need a large group of test lamps (say 100 to 1000) and then wait until 5% of that group fails. Then the normal 50% lifespan is extrapolated from that. Sort of like an educated guess.

 

[greenjp]

Originally Posted By: Samilcar
Originally Posted By: suspiciousmind
100,000 hours is about eleven and a half years. I don't know how lifespan could be calculated without testing them for about that amount of time.


Average lamp lifespan is usually defined as the point when 50% of a group of test lamps fail and 50% still work. So you need a large group of test lamps (say 100 to 1000) and then wait until 5% of that group fails. Then the normal 50% lifespan is extrapolated from that. Sort of like an educated guess.

LED lamps have a different criteria. Since the LEDs themselves may never really "fail", a limit for lumen depreciation is used. LEDs get less bright over time more drastically than say fluourescent bulbs. The "standard" for LEDs is 70% of initial output, after which time they're considered to be no longer meeting the original requirement and thus ready for replacement. There's a procedure called TM-21 which details how a certain test result (LM-80) can be used to estimate lifetime in this regard.

Of course this doesn't account for complete failure of the entire bulb/lamp, which can result from bad drivers, mechanical failure of connections, etc. It's possible, perhaps likely, that those things will kill an LED bulb before lumen depreciation does.

I believe LED will be the predominate interior lighting source in 5-10 years. I'm not buying any just yet.

jeff

 

[suspiciousmind]

^^^i agree with jeff....they're coming on strong and they're nowhere near perfected yet. Once they evolve in their design and production techniques, they'll predominate.

 

[91344George]

I also agree with the last two posts.....

One of the biggest issues I have with LED house bulbs is the color temperature...although the mfrs claim to have created a more natural white light with current LED bulbs I don't agree....BUT I must admit I am sensitive to blue (bluish) light...I don't like it AT ALL!

My favorite color temp is that of midday sunlight (white-yellow)
not sure what that color temp is in K ...anyone?

 

[daves66nova]

Originally Posted By: 91344George


My favorite color temp is that of midday sunlight (white-yellow)
not sure what that color temp is in K ...anyone?
maybe 3000k?

 

[greenjp]

Incandescent lamps are 2700K. Many CFLs are made in this same temp to provide that "classic" look. Typical office fluourescent lighting is 4100K. You can usually find 3500K bulbs in a big store, these I personally find to have a nice balance of warmth and somewhat whiter appearance. There is some work going on now looking at 5000K lighting for office type environments, I think it's a little too cool but some test installations have gone well apparently. FYI midday sun is actually much cooler than you think, 5000-7000K. I'll get my chroma meter out on the next clear day and check.

Somebody else mentioned the Color Rendering Index. By definition, sunlight and incandescent bulbs are 100. Regular fluourescent bulbs are in the 70s, higher end ones are in the 80s. LEDs likewise are typically in the 70s and 80s. A new thing called the Color Quality Scale is being developed to improve this metric.

jeff

 

[Pablo]

I agree with not jumping on this wagon yet. The CFL thing was a financial failure in my house. I've had them last less than a year, the majority not even two years, at 5X the price. What a joke. I won't go one about the weaknesses of CFL's here, but they never turned out to be anywhere near the promises.

 

[Cujet]

I'm having trouble locating conventional 100 watt light bulbs. I went to Homeless Depot, Lowes, Walmart and they are all out of the 100 watters.

My house is nearly 100% CFL, however, in winter, when it's blisteringly cold here in South Florida, the CFL's are exceedingly slow to warm up. So, I wanted to use one ea. 100W conventional bulb in my "high hats" (flush ceiling lighting) to get instant light. I found one in the attic and it works perfectly, like God intended.

I went to Costco and purchased an LED "flood" light. The "so called" warm white color temperature does not match my Sylvania 2700K CFL's. So it looks really out of place (comes on instantly though). It's also a bit down on light output.

So, I guess I'm going to have to wait until readily available 1600 lumen, 2700K LED lights are available.

Oh well. At least my CFL lifespan issue has settled down and I've weeded out most of the bad ones. I'm certainly not replacing them as frequently as before.

 

[The_Jeff]

Originally Posted By: greenjp
Incandescent lamps are 2700K. Many CFLs are made in this same temp to provide that "classic" look. Typical office fluourescent lighting is 4100K. You can usually find 3500K bulbs in a big store, these I personally find to have a nice balance of warmth and somewhat whiter appearance. There is some work going on now looking at 5000K lighting for office type environments, I think it's a little too cool but some test installations have gone well apparently. FYI midday sun is actually much cooler than you think, 5000-7000K. I'll get my chroma meter out on the next clear day and check.

Somebody else mentioned the Color Rendering Index. By definition, sunlight and incandescent bulbs are 100. Regular fluourescent bulbs are in the 70s, higher end ones are in the 80s. LEDs likewise are typically in the 70s and 80s. A new thing called the Color Quality Scale is being developed to improve this metric.

jeff


Back in the day CFL makers thought we liked the warmth. But those bulbs just make everything look orange and brown... their phosphors probably have a bad CRI. I sometimes mix one of those in with two cool white ones.

If the pigments in your paints and decorations clash with CFLs that could be an issue too.

 

[Ursae_Majoris]

Originally Posted By: greenjp
IThere is some work going on now looking at 5000K lighting for office type environments, I think it's a little too cool but some test installations have gone well apparently. FYI midday sun is actually much cooler than you think, 5000-7000K. I'll get my chroma meter out on the next clear day and check.


Years ago I worked in offset printing. We replaced all our lights with 5000K tubes to simulate daylight. Made color calibrations and proofing much more consistent. 15 years ago 5000K T12 tubes cost an arm and a leg and a firstborn.

 

[Hokiefyd]

I'm hopeful about LEDs. Like Pablo, and probably others, I haven't been all that impressed with CFLs. I've had a few with bad ballasts (so end up replacing expensive bulbs with incandescents anyway), but one failure was particularly alarming. Started smelling a burning smell and the ballast of the CFL in my table lamp was smoking. It turned a discolored brown on the outside and was so hot you couldn't touch it. I'm leerly of leaving CFLs on for extended periods of time since. A fire can ruin your day for sure.

 

[JTK]

I've been intrigued by LEDs for home use too, but just can't justify the cost.

I know some of the street, parking lot and commercial canopy lighting in my area has been converted to LEDs and the light output and quality is impressive.

With CFLs so cheap, that's all I use now. I've got TONS of ceiling mounted lighting that I've converted all with compact 60 watt CFLs. Most of which I bought for under a dollar a piece.

As far as my ceiling fan fixtures, I've yanked all the power wasting dimmers and replaced them with regular switches so I don't have to worry about CFL use.

Joel