nisakhan

Gary, YYZ, and chubbygumby: I applaud you for carrying on a professional discussion without getting mad at one another. I think while both sides have valid points about power factor and various tutorial could be given with PF inclusion, I tend to agree with Brian. You can assume the most efficient PF for both, and concentrate on other energy savings issues for comparison based on final live-size products of interest. Energy savings for LEDs currently mostly have to do with scaling and light distribution that are very different from neon and fluorescent lights. (It is more than just saying LED efficacy can be or will be higher.) The result is that when one looks at an illuminated sign (or a luminaire even), the effective light to our eyes (or in the case of a luminaire, light incident on an illuminated space of interest) is just more than adding lumens - which of course is meaningless unless you define where to add them. Energy savings for LEDs also needs to consider what energy is being consumed when one makes them in a semiconductor fab factory. I can put this on the back burner a little bit for now and mainly focus on the above issue. But, to all of your points, I would add appropriate material for PF too, just to cover enough grounds. Cheers! (And, Happy Birthday - Brian!) Nisa

Hello Forum, I thought I would chime in. I don't post much and am not able to always keep up much with the discussions on this site. But, I was aware that in some cases, neon signs would win. Among many things contributing to this comparison, for certain size signs (channel letters and cabinet signs), neon's light distribution is more favorable at this time; further, it is a more mature technology than LED. While I am not an LED advocate, but rather solve LED design problems, I would say that LEDs, with proper design implementation can match neon's light distribution performance for many flat signs. But the key is having the right optical, electrical, and thermal designs, as well as solid-performing LED modules that only some vendors offer. So my prediction is that over time, LED designs will improve and replace more and more neon signs. But neon may still have some applications - why? Because, well, it is neon! Perhaps more on this later. Nisa Khan

---------------------------- Hi Erik, Thanks for your comment. While I didn't quite understand your comment on the issue with "environmentalists", my article didn't address challenges on environmental issues. The columns need to be short or contained and it doesn't make sense to address all challenges, pros and con's of LEDs vs. incumbent light sources - the linear fluorescent lights in this case. The theme of the article is addressing the energy savings issue. I chose this issue because there are some misunderstandings in the lighting industry and too much money may be getting wasted on the wrong things. I have my experience, thoughts, and information on environmental issues of LEDs and other Hg-based sources. The environmental issues of LEDs are not as straightforward and benign as some might think. There are many things to consider and hopefully over time, the real issues will be resolved scientifically, rather than emotionally and politically with misinformation or lack of information. Cheers! Nisa

I agree with YESCO - perhaps the Denver City Council can reconsider their decision. Well-regulated LED billboards add valuable information and modernity to cities. The type of billboards built by YESCO and similar companies are praised by almost everyone I have talked with in various cities. (Ref: my ST EDS column, Oct.2009, page.44). OAAA can come to aid - their website is very comprehensive. There are however many monochrome electronic message centers (not considered billboards) I have seen in front of shops, plazas, schools, and alike that appear too bright at night. These should be properly controlled electronically based on ambient light. Some LED traffic lights are also too bright. LEDs can be controlled for their brightness quite easily. Adding this feature will increase cost a bit - but it is worth it because you'll save energy and boards will be readable and attractive. Nisa Khan LED Lighting Technologies

Dear JR Neon: I am new at posting messages here and don't know how to navigate too well here. I have tried to read and enter into certain web location in the past on Sign Syndicate, but failed. So I hope my message reaches you. If not, please feel free to email me at nisa.khan@ieee.org for further web conversation. I apologize if my writing was not clear on "upscaling". I wrote in general terms for both channel letters and cabinet signs actually. I am impressed that your company put up very large cabinet signs on sky scrappers. But, my impression is that since LEDs are small modules and can be integrated in various ways on modular boards that can be joined together in many different configurations, the upscaling would be much easier than neon for any type of signage or display. But, I do see that my point is better made for channel letters that have more complex shapes than just strips of light for internal cabinet illumination, which can be done with neon also. Thank you for the good question. Nisa Khan