Rab lighting has just released a 3429 lumen LED wall pack intended to replace 240W wall packs. it specs out at 57 lm/w. The mfgs are finally starting to get the spec sheets right. This one shoes lm/w, photometrics, complies with LM 79 and LM 80. They don't state the color temp and the cooler the source the more efficient it is. Beta lightings spec sheets are well done, and have the BUG ratings, the Rab still uses the obsolete cutoff desginations.

While LED's seem to be the hot topic, if you do your homework you might find that other lighting is half the price, lasts twice as long and doesn't have the problems with heat dissipation that LED's have - check out induction for one. I agree that there is not one light source to meet every need but we need to know about all the types so we can service our customers and meet their needs better. We have just gone through, and are continuing to go through, the research mode and have learned to not just listen to sales people but try them out for yourself. Good Luck!

I don't know if any of you are mythbusters fans, but they recently were looking at the myth that it was cheaper to leave lights on rather than turn them off each time you leave a room. During the course of this investigation, they decided to do a 'real world' life test on the variousl lights including conventional flourescent, CFL, Incandescent and LED. The simulation cycled lamps off and on to the equivalent of some years. At the end, the only lamp that hadn't failed was the LED. Some food for thought.

I have been to 5 o6 2 1/2 day street lighting conferences over the last 6 years, and am a member of the IES Roadway Lighting Committee. LED lighting is here. LED lamps are now at Costco. We as electricicans must become familar with the this technology. We need to think in terms of luminarie replacement, not lamp replacement, perhaps once in your career. For those who doubt LED technology, the traffic signal industry was a early and successful adopter of LEDs. Many agencies are on the third generaton of signal lamps. Going from 116 watts to 20 watts is a big savings in energy. But for most applications, they are still expensive compared to incandescent. There have been many large scale street lighting installations of LEDs-Ann Arbor, Anchoridge...

Befire the China olympics, there were so many failures of LED street lighting, the chinese government would not allow any more to be installed.

Thermal mangement is the key to long life. The LED only converts 20% of the power to visible light, the rest is heat.

And I found out that the LED mfgs bin the LEDs to determine the best output and they keep those for their own use.

The actual UL applicant = "Fiber Optic Designs". The CCN indicates UL approval for decorative lighting only.

The patents listed on the company's website seem to be full of non-original use and prior art.

LED technology is certainly improving and will no doubt be THE choice in the future. We do need to remember a couple of things, though...

The life expectancy of a CF is when it stops working - full bright one day and full dead the next. The life expectancy of an LED is when the lumen output has dropped to half what it was when new. This can skew ROI numbers. A customer will want the bulbs replaced when the room is too dim, not when some paper says time is up. I really do wish LED manufacturers would publish their charts!

One must also look at lumens per watt per dollar. CF bulbs still rule that roost, although LED bulbs are catching up fast.

I have been closely watching the developement of this industry for the last year or so. Each item I have investigated has been a dissapointment. The replacement lamps for florescent tubes deliver an inconsistant light, just don't look right, and are very expensive. Par 20 and 30 and MR16s were similarly dissappointing. Streetlights and parking lot lights however are a different matter. The time for these lights is here. Check the website betaled.com for some examples. I haven't got final prices yet but I am watching the City of Los Angeles which has pilot programs looking at different manufacturers. It seem clear that even the leds that claim domestic manufactering are simply assembled here and most of the products rely on Cree to supply them with product. Jack Miller

The very first statement in this document is marketing hype.

LED's, at least the ones available today, are not very efficient. A typical LED that I've run across in the last year runs about 20 lumens per watt, half as efficient as a compact fluorescent, and 1/4 the efficiency of a T-8 linear with electronic ballast.

Oh, yeah, there are LEDs in the lab that rate 200 lumens per watt, but you and I can't buy one.

There are a few manufacturers selling LED fixtures that are creeping up into the 70-80 lumen per watt range. This is *almost as good* as a garden variety T-8 lamp, which can exceed 90 lumens per watt.

None of these people hyping LEDs are telling the whole truth about efficiency - it is simply Greenwash to compare LEDs to incandescent bulbs - which are almost never used in new commercial facilities anymore. Most commercial facilities are using T-5 or T-8 linear lamps, or compact fluorescent downlights. Compared to those, most LEDs available today are poor choices. Expensive too!

This situation is changing, and will change soon. We're likely to see an LED fixture on the market exceeding 100 lumens per watt, but I am not aware of any that are available commercially today. If anyone can point me to one, I'd be pleased to know about it and spec it!

Twenty bulbs burning for 10 hours per day!?!?!?

That would be equal to my wife and I arriving home from work at 6:00 PM, turning on almost every light in the house and staying up until 4:00 AM. On a dark and stormy winter evening we might do 3 lights for 4 hours.

Will anyone else be able to make up the rest of our share of the load? I'd like to hear from you.

Dear Mark:

I'm very interested in led lighting because in my country (Chile) advertising says that is cheaper than HID lighting (HPS and HM) but I couldn't find serious papers about these lamps. ¿Is the lamp life measured in the same terms that other lamps? ¿Are there isocandle curves or similar tests of luminaires with led lamps? All the information related to these lamps I get is vague or, in certain cases, malicious.

Rgds,

Pedro Salas

As ever, the articles included are very interesting and appealing, but in this case, I think that the ROI study lacked of the initial investment data. They should have included the initial costs of an incandescent bulb and the LED substitute. With these data included, I still think that the LED option is feasible, but not as economical as the vendor tries to tell us... a vendor, after all. ;)

I remember when the media was full of such studies regarding CFL (Compact fluorescent lamps), but it turned out lately that the real life of these lamps was smaller that the thousands hours promised, making CFL almost as costly as incandescent... but, hey, I'm talking about México, where the voltage sags are daily events. :(

Anyway, I'm still with the energy savings options, and spreading the word!

this is about the 4th time I can't open the letter ... what program do I need to read these ... help ... mario

Mike Over the last 5 years we have switched out all our navigation,anchor,and interrior lighting to led. The cost is starting to come down finally.

Are there any concerns or issues about retinal damage due to the use of LED lighting in the white spectrum.

I think that LEDs are the future of lighting, but if you look at their delivered light they aren't any better than CFL or HID. in most cases they are worse. They do have many good advantages, but they also are higher in cost, don't dim well with all dimmers, and don't always have the best "beam", etc, etc. They are a nice tool to have, but they don't live up to the hype right now. I have high hopes for them in the future but for now they are simply a role player. My best advice is to get a sample and test it per your application.

This was a blatant piece of LED propaganda. Mike should stick to codes and safety, his evaluation of LED's is obviously lacking.

I hope there are more engineers than just me that think the LED industry still has too much smoke and mirrors with little substance. Mike should be ashamed of himself for passing on manufacturer's propoganda without listing the shortcomings of LED's or the other viable lighting alternatives.

has anyone used the halo h7 led bulb replacment unit

We have looked at LED’s to replace the incandescent and CFL light bulbs in our temporary string lights. Biggest problem is that LED’s are direct lighting and cast shadows and low light in the surrounding areas. The vendor tried to compensate with “reflectors” but it wasn’t much help. The over all lumens were half, at best, of the incandescent and CFL’s we now use.

I have found in the past that if you open the Mike Holt Newsletter in the View Comments Mode, Then when you then click on the link you save it to a file first to your computer you can open them.

Mark

LEDs hold a "bright" promise, but we are not there yet. I priced a LED wallpack, it was $800, while a similar luminaire in induction was $400. With LEDs, the key is to minimize junction temperature for long life. The life of an LED luminaire is called L70, the point at which the output is 70% of initial. I believe the biggest advantage of LEDs are: Precise control of the light pattern Easy to control No hazardous materials Remember the I-35 bridge in Minneapolis that collapsed? It was rebuilt in less than a year and has Beta LED roadway luminaires. The light levels are comparable to HPS.

All is not a rosey as your would think with LEDs. Read the series of reports published by the Caliper Program at: http://www1.eere.energy.gov/buildings/ssl/caliper.html Unfortunately this new technology is getting better, but unscrupulous vendors are still making claims beyond reality. Buyer beware. Get a sample to test before you try to design with it.

Also note, high intensity Blue light (from LEDs, or elsewhere) can casue damage to your eyesight. Blue is one of the primary LED colors in high brightness tri-color sources, and looking directly into them (like LED stage lights) can be hazardous. There are also UV LEDs now available, so just because it's an LED doesn't necessarily make it safe.

Cool to the touch may be questionable, as the junction temperature in an LED must be kept cool to give it long life. High Brightness LEDs, therefore, must shed heat via a heatsink at the rear to stay alive. This is one of the primary reasons converting incandescent fixtures to LEDs is such a challenge - we have engineered standard lamp sockets so that they don't conduct heat away from the lamp base.