Nichia Develops 60 Lumen Per Watt White LED

[Clocker]

I have 5 of these in my great room and I am not really happy with how much they will dim with my Lutron Diva dimmer. The lights are advertised as being able to dim down to 10%, the dimmer is brand new said to be compatible with LED & CFL. They only get down to a 60% brightness even with the adjustment all the way down. My fault for not checking the compatibility list. There are too many models of the same bulb!
http://www.lowes.com/ProductDisplay?catalogId=10051&langId=-1&productId=50223597

EDIT: What do you know, it IS on the compatible list. But still only goes to about 60%



I have 17 of these for the lights in my basement. They are fantastic and can dim really low with the same Lutron dimmer. Much better than the 9 year old 120W equivalent BR40 CFLs they are replacing.
http://www.lowes.com/pd_441164-43921-YGA08A35-17.5W-827_?productId=50244365

 

[Clocker]

REDUNDANT

 

[mubs]

You have 1000 watts input, about 700 watts waste heat.

Practically speaking, I know LEDs get hot, but aren't they supposed to be significantly more efficient (less heat) than other lighting technologies?

 

[Clocker]

Practically speaking, I know LEDs get hot, but aren't they supposed to be significantly more efficient (less heat) than other lighting technologies?

I have definitely noted that the LED replacement bulbs I am using are much *much* cooler to the touch than the CFLs they are replacing.

 

[LunarMist]

Practically speaking, I know LEDs get hot, but aren't they supposed to be significantly more efficient (less heat) than other lighting technologies?

Look at the rated lumens vs. the power input (watts). You will see a far less significant improvement between CFL and LED compared to the difference between incandescent and CFL.

 

[ddrueding]

Practically speaking, I know LEDs get hot, but aren't they supposed to be significantly more efficient (less heat) than other lighting technologies?

I have definitely noted that the LED replacement bulbs I am using are much *much* cooler to the touch than the CFLs they are replacing.

Both of these are true. LEDs produce far less heat for an amount of light (more efficient). However, LEDs need to be kept way, way cooler than other kinds of lights. LEDs are happiest under 50 or 60C, whereas halogens can happily be hundreds of degrees.

 

[jtr1962]

Practically speaking, I know LEDs get hot, but aren't they supposed to be significantly more efficient (less heat) than other lighting technologies?

Yes but not all LEDs are made equal. A high bin Cree running at 350 mA will probably put out 60% light, and only 40% heat. The LEDs used in this project were only about 90 lm/W at the current he was driving them at. A rough rule of thumb I use is efficiency = lumens per watt / 300. You might use a divisor of 330 for high CCT, low CRI LEDs, and perhaps 250 or so for low CCT, high CRI LEDs, but 300 is a good rule of thumb. That would put these at about 30% efficient. The remaining 70% of input power would come out as heat. Note that 30% efficient is still better than most fluorescent technologies which are in the 20% to 25% range (CFLs are in the lower end of that). Some high-spec T5 or T8 tubes hit about 30% but that's it. Production LEDs are already twice as high, and I'd say we're likely to pass 80% efficient within the next few years.

 

[jtr1962]

I have definitely noted that the LED replacement bulbs I am using are much *much* cooler to the touch than the CFLs they are replacing.

Yes, because small differences in efficiency can translate to large differences in heat output. A 100 watt equivalent CFL might use about 24 watts to put out 1600 lumens. 1600 lumens with a CFL spectrum is maybe 5 watts of light energy. Therefore, the CFL puts out about 19 watts of heat. I've seen 100 watt equivalent LED bulbs using as little as 16 watts. 1600 lumens with an LED spectrum at a medium CCT is perhaps 6 watts of light energy. That means 10 watts of waste heat, or not much more than half of what the CFL produces. Note that to achieve this reduction in waste heat the LED bulb only needed to be about 50% more efficient than the CFL in terms of lumens per watt.

We'll likely get to ~150 lm/W with LED bulbs in the next few years. A 100 watt replacement would only put out about 5 watts of waste heat, half the amount of today's best 100 watt LED replacement.

 

[LunarMist]

If the LED wastes 10W and the CFL 16 W, what does the incandescent waste?

 

[jtr1962]

If the LED wastes 10W and the CFL 16 W, what does the incandescent waste?

Probably about 90%, or 90 watts. Here's a good read on the subject. They give numbers from 2% to 13% efficient, depending upon the type and wattage of the bulb. 100 watt bulbs are about 10% efficient, 40 and 60 watt bulbs closer to 7.5%. Of course, these numbers are miserable compared to any other lighting technology.

 

[LunarMist]

Probably about 90%, or 90 watts. Here's a good read on the subject. They give numbers from 2% to 13% efficient, depending upon the type and wattage of the bulb. 100 watt bulbs are about 10% efficient, 40 and 60 watt bulbs closer to 7.5%. Of course, these numbers are miserable compared to any other lighting technology.

Of course incandescent E26 lamps are being phased out, but when will LED replace CFL? There were still more CFL than LED lamps at the store the last time I looked (August).

 

[jtr1962]

Of course incandescent E26 lamps are being phased out, but when will LED replace CFL? There were still more CFL than LED lamps at the store the last time I looked (August).

My guess is when the prices get close. The only reason CFL still exists at this point is because it costs less than LED. I'd say within 2 or 3 years that advantage will be lost. I've noted now when I buy emitters they're less costly than even 6 months ago. As efficiency continues to rise, the heat sinks will get smaller, hence less expensive. In fact, some 40 watt replacements are already using LEDs on MCPCB, with no separate heat sink. We'll be able to do that on higher wattage retrofits in the next few years.

 

[Howell]

How can I tell how much power the 12v power supply actually draws when the load is turned off? I'm trying to decide where to add in my switch for some ribbon lights.

 

[LunarMist]

How can I tell how much power the 12v power supply actually draws when the load is turned off? I'm trying to decide where to add in my switch for some ribbon lights.

Then measure the input power. Is that from the 120VAC mains supply?

 

[Howell]

Yeah it's a brick transformer. I don't have a good way to measure input power yet. I was going for a keyword in the specs to look for.

 

[LunarMist]

Yeah it's a brick transformer. I don't have a good way to measure input power yet. I was going for a keyword in the specs to look for.

Switching supplies used to have efficiency levels I to V, but that program was nixed about 5 years ago. If your PS has a level, then you can figure out some info. Otherwise get a power meter.

http://www.energystar.gov/index.cfm?c=archives.power_supplies

I found this chart elsewhere, but it should be the same.

 

[Stereodude]

Yeah it's a brick transformer. I don't have a good way to measure input power yet. I was going for a keyword in the specs to look for.

Get a P3 Killawatt. Then you can measure to your heart's content.

 

[Howell]

NM

 

[LunarMist]

Did you move to New Mexico?

 

[CougTek]

NM: nevermind

 

[Howell]

Kill a watt it is then. Thanks guys.

 

[Howell]

Not so fast LED:
http://www.techtimes.com/articles/1...gy-efficiency-of-incandescent-light-bulbs.htm

 

[jtr1962]

They're using incorrect figures in that article:

Compact LEDs' energy efficiency ranges between 5 to 15 percent. Fluorescent lights range between 7 to 15 percent while the top-notch incandescent bulbs vary between 2 to 3 percent.

CFLs are about 20% efficient, linear fluorescents up to 30%. The better LED bulbs are approaching 30%. 50% or greater efficiency is possible in the not too distant future. You can already buy emitters which are about 55% to 60% efficient.

 

[Buck]

So are they using the thermal characteristics of the redirected infrared frequency band to aid in heating the filament?

 

[time]

It's a shitty article and they're reporting on junk science - from MIT, no less!

I'm afraid I gagged on "soft, beautiful glow". There's nothing soft or beautiful about an incandescent bulb, particularly anything over about 25W.

 

[jtr1962]

It's a shitty article and they're reporting on junk science - from MIT, no less!

Even worse, my first attempt at pointing out the errors in the efficiency numbers was removed from the comments. I tried again, this time with a link to a source. Hopefully that will remain. Misinformation is bad enough, but failing to correct it when someone points out the mistakes is inexcusable.

I'm afraid I gagged on "soft, beautiful glow". There's nothing soft or beautiful about an incandescent bulb, particularly anything over about 25W.

No argument there. I switched to linear fluorescent decades ago just as much to be rid of the horrid yellow cast incandescents create as to save energy. Now I'm well on the way to having quite a bit converted to LED.

 

[mubs]

I replaced a working exactly 2-year old 23W 2700K 1550 lumens CFL with a 13W 3000K 1300 lumens LED, and it is quite a bit brighter (I know that the CFL has probably dimmed down a bit, but still) . This lamp is on about 5 hours each evening so I thought it worth replacing with something that drinks a bit less juice. Next up is my work light, also on about 4.5 - 5 hours each evening. E27 base was not available in ready stock, so in a couple of days. My work light is a Philips torchiere that has an E27 socket. The standard here is B22 (2-pin bayonet).

No more LEDs till the 2700K CFLs start dying. I'm the only goofball who asks for 2700K at the store, rest everybody uses that ghastly 6500K or 7000k.

One thing I don't like about the LEDs is that the light seems harsh and throws shadows. CFL light is softer, gentler on the eyes. We talked about this earlier - that CFL spreads light all around and the LEDs are more focused etc.

 

[ddrueding]

LEDs are effectively point sources. If you don't have a lot of them you should consider either diffusion or indirect light. A lot of the fixtures I'm putting in lately are designed to throw against a wall or ceiling. The two bedside lights I'm putting together mount into the ceiling, but are very long tubes that limit the circle of light to only the bedside table surface, reflecting from there.

 

[jtr1962]

I do the same thing with LED bulbs. I aim them towards the ceiling to effectively diffuse them. LED fluorescent tube replacements give a nice, diffuse light but of course you need 4 foot T8 or T12 fixtures to mount them in (and the fixtures usually need to be rewired to feed 120VAC directly to the tube sockets).

 

[mubs]

Yeah, you guys are right, I also thought the same.

My first powerful LED (12W) in my daughter's room is naked, on a side-wall, pointing down at a 45° angle. The one I put in yesterday is naked too, hanging down from the ceiling in the living room. The proposed one for the torchiere will point up at the ceiling, like the CFL in it currently does. This is a rented place, and I'm not keen on spending money on expensive light fixtures at this time. When I do purchase our own home, I will have to think carefully about how best to utilize LEDs. Some of the advantages of using them are lost if I have to use more of them to create indirect lighting. Power here is damn expensive, and they keep hiking the rate every year. If I ever have the money for it, I'd like to go off the grid completely like DD is planning to.

So DD, can you post a pic or link of your "fixtures that are designed to throw against a wall or ceiling" so I can get an idea?

jtr, I haven't seen any warm temp LED tube lights here. When I was buying my LED lamp at the store yesterday, a guy was buying a 4 ft tube LED, but it looked like it would be 7000k or at least 6500 which I can't stand. The common practice here is to have a bunch of power outlets in the ceiling; how you use them is up to you. Cheapies like my landlord just put lamp sockets there. How do you aim your bulbs towards the ceiling? Easy to do if you have floor-standing torchieres (which I like a lot, but they're difficult to get here, and quite expensive).

Most LEds here have a covering in the bottom half of the bulb, so they tend to put light out of the top half only, so it might be easier to direct the light up, but to direct light at the side wall will require the socket to protrude out of the side wall quite a bit and make a u-turn.

 

[ddrueding]

None of my recent fixtures are at my place, but JTR did wire up an LED conversion for an antique chandelier years ago. The LEDs are at the top of where the "candles" are and shine directly upward with no diffusion. From any place below the plane of the LEDs there is no visible source of the light, just a neat pattern on the ceiling. I'll try to get some pictures of more recent stuff soon.

 

[sechs]

I'm having an issue with some LED replacements that I have, and I'm hoping you guys can help me troubleshoot the situation.

Some months ago, I noticed the light in my living room starting to flicker. Since the bulbs are attached to a ceiling fan and I only noticed it intermittently, I dismissed it. As the incidences came more often and longer, I tried to figure out what was going on. In turns out that only one of the three bulbs in the light is flickering.

I got some Osram 8.5W, 800lm bulbs about a year ago to compliment the Crees that I already have. These were cheaper and (at least on paper) more efficient. It is one of these that is causing the flicker.

As a first step, a couple days ago, I swapped the socket on the fan that this Osram bulb was in, and so far, so good. Unfortunately, I'm starting to experience flicker in another room with one of these Osram bulbs in the fixture. Neither of these is on a dimmer.

I can't find any information on generic flickering issues with these, so it must be something specific here. Any thoughts on what I can do to figure out what's going on?

 

[LunarMist]

I'm having an issue with some LED replacements that I have, and I'm hoping you guys can help me troubleshoot the situation.

Some months ago, I noticed the light in my living room starting to flicker. Since the bulbs are attached to a ceiling fan and I only noticed it intermittently, I dismissed it. As the incidences came more often and longer, I tried to figure out what was going on. In turns out that only one of the three bulbs in the light is flickering.

I got some Osram 8.5W, 800lm bulbs about a year ago to compliment the Crees that I already have. These were cheaper and (at least on paper) more efficient. It is one of these that is causing the flicker.

As a first step, a couple days ago, I swapped the socket on the fan that this Osram bulb was in, and so far, so good. Unfortunately, I'm starting to experience flicker in another room with one of these Osram bulbs in the fixture. Neither of these is on a dimmer.

I can't find any information on generic flickering issues with these, so it must be something specific here. Any thoughts on what I can do to figure out what's going on?

It would seem that Ostram made crappy lamps if others work fine in those sockets in various locations. I suppose there is some chance that the mains power is dodgy and the LEDs are especially sensitive, but how much effort do you want to put into checking that? My experiences with LEDs and CFLs are not so great, with failures of various types far sooner than the rated life. The prices are dropping to the point that I would just replace them with something else.

 

[sechs]

If the bulbs are bad, they're under warranty, and I can get them replaced. Unfortunately, it'd be a bit of a pain, as I have to take them back to Lowes, and only one store in the area carries these.

I live in an older apartment building that's probably 80+ years old, and the mains power *is* a bit dodgy. I've set my UPSes to highest sensitivity, and they do switch to battery every once in a while due to undervoltage. These don't appear to coincide with flickering episodes and, in any case, the Cree bulbs don't seem to have any problems.

I only have the LEDs in the most-used lights, where they have the most impact on power usage. Everywhere else, I still use CFLs, most of which are well-past their rated lives.

 

[jtr1962]

I definitely sounds like an undervoltage issue. Some LED bulbs work fine down to 75 or 80 VAC, others might start to flicker at 100 VAC. Unless you can get your landlord to fix the mains power issue, which should be done anyway for a whole host of reasons having nothing to do with LED bulbs, I would just swap out the bulbs for something else. Probably nothing wrong with them, but their minimum design voltage is apparently higher than your mains voltage drops.

 

[mubs]

If it's under voltage, why do some flicker and not others? Because these flickering ones are more sensitive?

Over here, Osram has a phenomenal reputation in CFLs and all mine are Osram and nary a problem. But for LEDs, they are rated very poorly, for early death, dimming, and flickering. None of the few LEDs I have are Osram.

 

[ddrueding]

I'm guessing a power issue as well. All my LEDs that are _not_ dimmable have issues and fail early even if I don't have them on a dimmer. The higher-powered outdoor ones I have have actually killed a couple Insteon switches in addition to misbehaving themselves.

 

[Howell]

The only other thing I can think of is oxidation in the socket. Especially if disturbing the bulb made a difference.

 

[Stereodude]

Short of connecting an oscilloscope to the mains (which can be dangerous) and seeing if the power is doing something funky when the flickering occurs, I'm not sure how you can narrow it down anymore.

 

[jtr1962]

If it's under voltage, why do some flicker and not others? Because these flickering ones are more sensitive?

Some bulbs have lower minimum voltage specifications than others. And there's manufacturing variation even among the same bulb type. That said, it seems there are LED driver ICs which deal with 85 VAC to 265 VAC ( https://www.spansion.com/downloads/AD405-00011-E.pdf ). That would give LED bulbs a universal voltage range. Quite a few fluorescent tubes retrofits are already rated for 85 VAC to 265 VAC. Hopefully LED bulbs will be as well in the not too distant future.