Nichia Develops 60 Lumen Per Watt White LED

[sechs]

I picked up one of the Cree 100W equivalent bulbs last week. It's definitely brighter and throws the light better than the 24W 4U CFL that it replaced, but it's certainly not "daylight."

I have cool white bulbs that are far less yellow.

 

[mubs]

Strange stuff

I bought my first LED bulb a month back. It's 3-watt 3000k 270 Lumens, and sits 2 feet away from a CFL that is 23-watt 2700k 1550 Lumens. The switches are next to each other, so I can very easily do an A/B comparison.

Based on spec, the LED is about 17% the Lumens of the CFL. But I swear, it feels like it's 50 - 70% as bright as the CFL.

My second LED bulb is 12-watt 6500k 1220 Lumens. I swapped it with a CFL that's 32-watt, 6500k 2150 Lumens in my daughter's bedroom, and she whined that the LED bulb was way too bright! Helllooo??!!

Point I'm trying to make is, 1000 Lumens from an LED bulb seems drastically brighter than 1000 Lumens from a CFL. If this is a fact (and my experience indicates it is), then there is not an equivalence of Lumens between CFL and LED.

Anybody else noticed this? Why is this so?

So one can then replace a higher Lumens CFL with a lower Lumens LED and not notice an appreciable reduction in light. In the second case above, perhaps a 10-Watt LED would have sufficed. That is a saving of 22 watts per hour, or almost 69%. That is truly incredible!

 

[Clocker]

I think you should be comparing bulbs of the same color temperature.

 

[mubs]

In the first case, 2700k vs 3000k isn't a lot. In the second case, both CFL and LED are 6500k.

 

[ddrueding]

IIRC, lumens are total light output (all directions?) and LEDs tend to be significantly more directional. Less wasted light?

 

[mubs]

Well, LED bulb replacements for other types would be pretty useless if they were directional, right? The two bulbs in question disperse light like any incandescent, CFL or halogen would.

The only reason I can think of for the anomaly is that the CFLs are 26 months old and the LEDs are brand new. The higher power CFL is used 5 - 6 hours daily but the lesser powered one is used only intermittently; probably max of half hour per day on average.

 

[blakerwry]

I have noticed this to some extent as well. It seems like a "60 watt replacement" LED is brighter than a "60 watt replacement" CFL. I think it has to do with age, inaccurate (fuzzy) ratings, the color temperature (and how the bulb achieves that average color temp), CRI, etc. You'll also have to take into account warm up time of the CFL.

For those interested, I've been pretty happy with the Cree bulbs carried by home depot. I first installed a few in exterior applications outside the house and started replacing all my bulbs in the house with them as the old ones die. I now have ~ 12 installed in bathrooms, ceiling fans, and other overhead lighting inside and outside the home. A19, BR30, can light retrofit in a closet. Not a single complaint.

 

[mubs]

You'll also have to take into account warm up time of the CFL.

I did.

We don't get Cree here; the only "international" brand available is Philips. And they're supposed to be the best available here, considering all aspects. At more than 2x the cost (street price) of an "equivalent" CFL, LEDs are way too expensive now for me. I got these two as an experiment. Now I'll only buy them when my CFLs start dying. Unfortunately, I have a ton of 6500k CFLs that I hate; I replaced about 6 of them in the family room with 2700Ks. Now the 6500Ks are in very few places. Since the light(s) in the family room are on every evening, they will probably die first, and will replace those with 2700K or 3000k LEDs.

Why is jtr silent on this issue? Talk to me, jtr!

 

[Howell]

As had been mentioned, leds are directional. They simulate the less directional output by using multiple leds inside the bulb. I have some that are clearly dimmer in the axial direction, and you can see the subtle hot spots in the radial direction.

And as you've already mentioned, your cfls are old. Those are my guesses too.

I wonder if there is a way to make a diy light meter. Maybe with a camera and exif data?

 

[time]

The two bulbs in question disperse light like any incandescent, CFL or halogen would.

That would be well-nigh impossible. Think about how each light source actually works. An LED without a lens probably has a beam angle of about 150°, whereas the other sources emit in a full 360° spherical pattern. In practise, LED's usually use some sort of lens that results in a much narrower beam angle - 100° is very common for a 'replacement bulb'. Even that may be misleading: the angle is normally based on the point where light intensity drops to half that of the maximum, but that says nothing about how uniform the distribution. Many or most LEDs have a 'hot spot' surrounded by not very much at all until the intensity falls off a cliff. In my experience, claimed beam angles for LEDs are usually exaggerated, so when they say 60°, it's actually 40°, etc.

Putting it all together, 'replacement bulb' LEDs might have a real beam angle of 120°, which means their light directed towards the ground is 3 times more intense than an equivalent CFL (which actually throws more to the sides than straight down), so a 3W LED can match a 9W CFL - when considering solely how objects are directly illuminated.

On top of that, CFL bulbs seem to lose efficacy much faster than linear tubes, as well as only achieving maximum brightness after a couple of minutes each time.

Conversely, LEDs aren't always the answer. While I use 11W LED in wall uplighters with end-mounted bulbs, I also have uplighters with side-mounted bulbs, so I use 17W CFL bulbs in them. And my garage is lit with surface-mounted T5 linear fluorescent tubes that bounce most of their light off the ceiling and walls.

 

[Howell]

Time's second para describes the difference between lumen and lux that might affect perceived brightness.

 

[jtr1962]

I did.

We don't get Cree here; the only "international" brand available is Philips. And they're supposed to be the best available here, considering all aspects. At more than 2x the cost (street price) of an "equivalent" CFL, LEDs are way too expensive now for me. I got these two as an experiment. Now I'll only buy them when my CFLs start dying. Unfortunately, I have a ton of 6500k CFLs that I hate; I replaced about 6 of them in the family room with 2700Ks. Now the 6500Ks are in very few places. Since the light(s) in the family room are on every evening, they will probably die first, and will replace those with 2700K or 3000k LEDs.

Why is jtr silent on this issue? Talk to me, jtr!

I read all the posts here but I'm still trying to square away what you're seeing with my experience, namely that the LED bulbs I've tried don't seem much brighter than an equivalent CFL. Anyway, some of my theories:

1) An LED spectrum is far less spiky than a CFL spectrum, even if the CRI numbers are similar. That's actually why the lighting industry is trying to move to a new standard for color rendering. CRI doesn't really do LEDs justice. Objects lit under a CRI 82 LED look much better than when lit under a CRI 82 CFL. I've noticed this myself. Anyway, in general light which renders colors better has a higher apparent brightness. This may be part of the explanation.

2) Light degradation in the CFLs. I don't know how old your CFLs are, but they do in fact degrade in brightness noticeably before dying. If your CFLs are a few years old, they may have lost up to 30% of their output. Brand new LEDs may in fact be putting out slightly more than their rated output.

3) Mains power supply and regulation could be a factor. In general, I haven't seen any CFLs which are "regulated", meaning the light output stays constant when the mains voltage fluctuates. Legally, they don't need to be since they're rated at 115 VAC or 230 VAC, depending upon the usual mains voltage in the country where they're sold. In general, output will dim if mains voltage drops. Not necessarily so for LEDs which usually have a constant current regulated supply. They need to have this to keep from burning out. I've tested LEDs where the output remains virtually constant while the mains voltage fluctuates from 85 VAC to 130 VAC. If the mains voltage is very low in your area, then this could be the primary cause of what you're seeing. The mains voltage in my house is actually a little high, about 123 VAC, so CFLs here are probably a bit brighter than rated.

4) Directionality. While an LED may at first glance appear to emit light uniformly, most of them still emit light somewhat more strongly in one direction, often in the circular direction around the base.

On color temperature, if you hate 6500K you might try something intermediate. I know LEDs are coming out in 4000K and 5000K. Much better than 2700K or 3000K in my opinion but not the "X-ray blue" of 6500K. However, I'm guessing your daughter likes 6500K. Nothing wrong with that. I find 6500K is personally something I could get used to, but I find 5000K more pleasant.

 

[mubs]

Thanks time and jtr for the responses.

time:

The CFL throws light everywhere, including gobs of light on the ceiling when mounted as a downlight, and on the sidewall when mounted at a 45 degree angle facing downwards.

All my LED bulbs have some sort of covering at the bottom half of the bulb, which I presume is a reflector. There is no light thrown on the ceiling or side wall as the CFL does.

So agreed, the LED can look brighter. But for all practical purposes, for general illumination, the LEDs rated at a lower lumens seem way brighter than CFLs rated for higher lumens. I did notice shadows were sharper though when using LEDs.

I speak as a layman observing the result, without getting into technical details.

jtr:

1) I did read somewhere that CRI is in reference to a source. So if the source reference for an LED is different from a CFL, that would be like comparing apples to oranges, so you're quite right here. There's also quite a lot of fudging that happens with CRI ratings.

2) Certainly a factor. But AFAIK, LEDs too degrade over time, right?

3) No issues with voltage fluctuation here.

4) Just looking at the way the room is illuminated, one does not get the feeling at all that the light from the LED bulb is directional.

Color temp: It seems I'm in a minuscule minority that likes 2700k. 98% of bulbs sold here are 6500K, and there is nothing in-between except for a few 3000k from manufacturers that don't make 2700K. The 6500K light seems to hurt my eyes; natural daylight doesn't. Some CFLs claimed to be 6500K actually seem closer to 7000K or higher, especially the ones > 30 or 35 watts. Too darn blue.

 

[Tea]

JTR, while you are on deck, do you happen to know if there is such a thing as a readily available LED bulb that is immune to the fluctuations introduced by an old-style dimmer? As I understand it, all LED bulbs drop the high voltage AC supply down to a useful DC working voltage (5v or so, I imagine, something small anyway) and it should be very simple to design the bulb power circuit such that it doesn't care about a mangled input waveform, but does any manufacturer actually do it? (I tried a few different random brands a few years ago on this switch, some struggled with it, most were hopeless. CFLs don't like it either. The right answer is, of course, to replace the switch but I don't want to. One day I'll have that whole wall rewired properly, which will mean stripping the lining off. I plan to do that, but I have 103 other jobs to do first. Might be a year or three yet. In the meantime, I'm running a 100w incandescent bulb 'coz nothing else works.)

 

[Bozo]

How about a LED bulb labeled as dimmable?

 

[jtr1962]

JTR, while you are on deck, do you happen to know if there is such a thing as a readily available LED bulb that is immune to the fluctuations introduced by an old-style dimmer? As I understand it, all LED bulbs drop the high voltage AC supply down to a useful DC working voltage (5v or so, I imagine, something small anyway) and it should be very simple to design the bulb power circuit such that it doesn't care about a mangled input waveform, but does any manufacturer actually do it? (I tried a few different random brands a few years ago on this switch, some struggled with it, most were hopeless. CFLs don't like it either. The right answer is, of course, to replace the switch but I don't want to. One day I'll have that whole wall rewired properly, which will mean stripping the lining off. I plan to do that, but I have 103 other jobs to do first. Might be a year or three yet. In the meantime, I'm running a 100w incandescent bulb 'coz nothing else works.)

My understanding is quite a few LED bulbs work well with old-style dimmers. You just need to get something which says on the package it will work with a triac dimmer.

 

[Bozo]

I would think an 'old style' dimmer would be a rheostat type. They would fry the electronics in the bulb.

 

[ddrueding]

All of these dim well with normal dimmers:

Link: http://amzn.com/B00WQFNCAW
Link: http://amzn.com/B00AH2OXFE
Link: http://amzn.com/B0094BDAYE
Link: http://amzn.com/B006MNHZIO

 

[Tea]

Excellent! Now all I need to do is (a) order the globe, and (b) write a letter to the authority in charge of regulating power in Australia asking them to switch the country over from 240v to 110v. Easy!

But seriously now, the fact that these are available suggests that there should be equivalent products available for this market. (It's hard for me to order anything on-line or by mail at present because I don't have a suitable delivery address until I finish moving.) I had a look in a shop today but none of their extensive range seemed to be dimmable, and nearly every globe was too weak anyway. (I used to use a 100w incandescent, now replaced by an equal-brightness 75w halogen).

Maybe I should just bite the bullet and bring forward the renovation of that part of the house - rip the wall lining off, rewire completely adding extra lines, install about three, maybe four different fittings for various different purposes. Security & convenience auto-light, reading light (I sit out there under the porch more often than I sit inside; even in the middle of winter I spend at least some time there every day 'cause I just like the fresh air, work light 'coz I use that area for carpentry and such. But if I'm going to do that, it would make sense to get the sparkie to do the other jobs that are way past needing doing at the same time, and to do them I need to do various other jobs first, and find the money to pay him (everything else I can do myself) and put off various higher priority tasks such as building the new shed, finishing the renovations on the shop so that I can sell it (big job!), replacing the concrete of the front verandah, repairing the roof, moving the front door to a more practical part of the room, relocating the driveway, pruning the fruit trees, building the new front fence (which also needs a small retaining wall), finishing the brick paving Tannin started 30 years ago, and buggering off up the bush as often as possible with a camera.

I'm not sure why I bothered with this life-as-a-human caper. It was easier in the jungle.

 

[mubs]

Those same bulbs DD linked to might be available on Amazon.uk which would be voltage compatible for you. I'd order from there too, except for frickin red tape customs and such.

 

[ddrueding]

Just get Hue bulbs controlled by your smartphone (and get a smartphone) and abandon your wall switches altogether.

 

[Howell]

Aye, the most important characteristic in the led bulbs I've been buying is not color temp or cri. It's zwave.

 

[mubs]

You guys in US live in a world of your own. The rest of the world lives very differently.

A Philips Hue Starter Kit consisting of 3 Hue bulbs with E27 base, 1 bridge, 1 power adaptor sells here for ~ USD 265. One must be absolutely nuts or absolutely filty rich to spend that kind of money in this country for the "convenience".

 

[jtr1962]

You guys in US live in a world of your own. The rest of the world lives very differently.

I was thinking the same thing. $10 or less about the most I would spend on an LED bulb.

I will however spend a lot more than that if the situation calls for something besides a standard screw-base bulb. I spent ~$150 for 6 high-CRI LED tubes in my workroom. I've also made a number of custom jobs.

 

[ddrueding]

The bulbs I put into my house were ~$50/ea. IIRC there are 50-ish in the house. The $2500 spent on bulbs is probably about the same as I spent on the Insteon control system I put in while I was re-wiring the house. As a percentage of the value of the house (1.3%?) it is insignificant to the perceived value add, even before looking at energy savings.

 

[Tea]

You are a funny man, dave.

 

[ddrueding]

Inflation and variations in cost of living and property values can make some numbers seem funny to some people. That is why you go back to the numbers for perspective.

 

[Tea]

I meant this post.

Just get Hue bulbs controlled by your smartphone (and get a smartphone) and abandon your wall switches altogether.

You meant me?! :lol:

 

[ddrueding]

I meant this post.



You meant me?! :lol:

Absolutely. My kid (2.5yrs) is pretty handy with a smart phone. By 7 you should be able to master it easy. Lack of pockets might be an issue, though.

 

[mubs]

Cheaper LED with 25 times more power developed

Presenty 400 candelas per m[SUP]2[/SUP]; this technology takes it to 10,000 candelas per m[SUP]2[/SUP]

If this is true and can be commercialized, it would spark a lighting revolution. Oddly, the only links on the web for this point back to an Indian newspaper. The newspaper attributes the news item to the Press Trust of India.

 

[LunarMist]

Cheaper LED with 25 times more power developed

Presenty 400 candelas per m[SUP]2[/SUP]; this technology takes it to 10,000 candelas per m[SUP]2[/SUP]

If this is true and can be commercialized, it would spark a lighting revolution. Oddly, the only links on the web for this point back to an Indian newspaper. The newspaper attributes the news item to the Press Trust of India.

Maybe brighter lights can be made, but there is no data on efficiency. I suppose it is just in the lab for now.

 

[snowhiker]

I've been buying these 40-watt and these 60-watt equivalent 2-pack LED bulbs. $10 for the 40w 2-pack and $15 for the 60w 2-pack from the local Safeway grocery store.

The LEDs are replacing the hodge-podge of various different sizes and shapes of compact florescent bulbs. The LED are much brighter than the CF bulbs of same wattage and have zero warm up time. I don't know how long the LEDs will last but my CF bulbs did not last any longer than traditional incandescent bulbs. These were "cheaper" CF bulbs, so perhaps that's why they haven't lasted all that long.

Four of the original five, 75-watt incandescent bulbs in the kitchen ceiling are still working after 13 years.

 

[Stereodude]

Totally impractical, but I want one.

https://www.youtube.com/watch?v=-JVqRy0sWWY

 

[Handruin]

Totally impractical, but I want one.

https://www.youtube.com/watch?v=-JVqRy0sWWY

I saw that the other day and was really impressed. I'd love one also but would have no real use for it other than to show off to friends.

 

[ddrueding]

Yup. Have you figured out the cost yet?

 

[jtr1962]

You could probably make it a lot more compact with a fan-forced heat sink. In fact, if you do the math you have 1000 watts input, about 700 watts waste heat. If you want to keep the temperature under maybe 60°C and the ambient is 25°C, you need a heat sink with a thermal impedance of (60-25)/700, or 0.05°C/W. Not hard to reach that number. A 5"x12" heat sink with 2" fins and a decent 120mm fan would come close. You'll still need a battery and current regulator, but you could heat sink the MOSFETs from the current regulator to the same heat sink. That said, interesting project. In concept this reminds me of the former Soviet Union's Tsar Bomba. It worked, but in the end it was far too powerful to be of any practical use. Same thing here. This thing gives so much light it washes out whatever you're looking at. It might have been a more useful light without the optics-same amount of lumens but spread over a much larger area.

 

[Stereodude]

I saw that the other day and was really impressed.

:erm: And you didn't think to share with the rest of us? :scratch:

 

[Stereodude]

Yup. Have you figured out the cost yet?

No, I wasn't that serious.

 

[LunarMist]

What would the TSA do with that light setup?

 

[Stereodude]

What would the TSA do with that light setup?

Break it and possibly steal it.