From: John De Armond Newsgroups: rec.outdoors.rv-travel Subject: Re: LED light results -- short Date: Thu, 30 Mar 2006 15:25:46 -0500 Message-ID: <nt9o229ir8fqd7b50offte0hivf9srd4dj@4ax.com> On Thu, 30 Mar 2006 06:54:43 -0800, "Dusty" <RV_phixer@innerREMOVETHISlodge.com> wrote: >"Neon John" <no@never.com> wrote in message >news:bopm22p1jshj9u554du015m399b0e70ka1@4ax.com... >... >> Actually, LEDs are a poor way to go for boondocking. They're only >> a >> little more efficient than incandescents. >Huh? "Neon John", this flies against everything I thought I knew >about LED's. I've done the math...and I don't follow you. Could >you please elucidate? Sure. Here's a table that I put together from published manufacturer's data about a year ago: Lighting efficiencies - Initial lumens per watt. Conventional ballasts where applicable. High pressure sodium-- approx 125 lumens/watt (Osram) Low pressure sodium-- 150-180 lumens/watt HID-- 80 to 110 lumens/watt* Automotive D2S 35 watt HID 91 lumens/watt Solarc low wattage HID 45-60 lumens/watt 32 watt T8 fluorescent-- 85 to 95 lumens/watt standard F40T12-- 60-65 lumens/watt compact fluorescents-- low 30's to low 60's lumens per watt, usually 48-60 Sulfur lamp-- 53 lumens/watt Tri-phosphor neon-type cold cathode-- 60-80 lumens/watt T3 tubular halogen-- 20 lumens/watt white LED-- 15-19 lumens/watt standard 100 watt incandescent-- 17 lumens/watt incandescent night light bulb (7w)-- 6 lumens/watt incandescent flashlight bulbs-- less than 6 lumens/watt * HID lamps and ballast designs vary widely. I put this chart together to use in countering the outright lies that some LED sign suppliers are telling to try to compete with neon. Unfortunately LED vendors, even some otherwise reputable ones, are simply lying about efficiency. Another issue seldom mentioned for LEDs, particularly the high power and phosphor-based ones, is the dimming curve. High power and phosphor LEDs are not like those "last forever" low power LEDs in calculators and pilot lights and such. According to the ISA (International Sign Association - neutral as far as lighting technology goes), some LEDs are down to half the initial output in as little as 1000 hours. Few go beyond 7-8khours to half output. Since I put this chart together, LEDs have gotten a little better, phosphor-free Tri-Die white LEDs have come to market, CFLs have improved a bit, CCFLs have come along and low pressure sodium lamps with better color rendering but with about the same efficiency have become commonly available. Still this chart is highly representative. You'll notice that any of the fluorescents are many times better than LEDs and that LEDs are on par with medium sized and larger quartz-halogen incandescents. Only in the small sizes where envelope and filament holder quench greatly affects the incandescent's efficiency are LEDs superior. For general area lighting, LEDs are pigs - about equivalent to halogens. If you want a point-source of light, say, a reading light or to illuminate a spot outside at your campsite, you'd be better off efficiency-wise with one of the SolArc small HIDs. Here is a nice little 13 watt unit, the first item on this page: http://www.trailtech.net/motorcycle_hid_parts.htm I have two of these lights. One, with the spot reflector, is the headlight on my electric scooter. The second, with the flood beam replaced a 55 watt halogen lamp as my reading and general campsite light. It provides enough light for general activities throughout my entire rig. For all other types of lighting, inverter-driven CFLs provide the best bang for the buck. 12 volt versions are available but they're not worth the extra money, considering how cheap small inverters are now. After I get some of the CCFLs to evaluate, I suspect that I'll be recommending them instead of CFLs for RV use. > >> The way to go for low power is with fluorescents. Especially the >> compact fluorescents because the rare earth tri-phosphors they use >> are >> more efficient than the old halo-phosphates that most conventional >> fluorescent lamps still use. >Yeah. They are better than incandescents. But only by a rather >small percentage when compared to the LED's that I knew... Oh, just a factor of 3 or better. John From: John De Armond Newsgroups: alt.energy.homepower Subject: Re: CF recommendations Date: Sun, 25 Jun 2006 11:52:50 -0400 Message-ID: <h8bt92drtol3lohadr54a4r4lgt4b7fvnq@4ax.com> On 25 Jun 2006 06:48:22 -0700, walter_lee@my-deja.com wrote: >Barry wrote: >> Thought this group might have some useful info. I have replaced the 17 65w >> bulbs in our basement exercise room with Compact Flourescent. They are the >> Indoor flood type bulbs. I love how bright they are and use little energy. >> Unfortunately, I bought them in cheap packages of 5 from Home Depot. The >> problem is that they take about 2 minutes to warm up and are very dim when >> first turned on. Does anyone have any info on good quality CF indoor floods >> that turn on instantly that I could use to replace them? I often go into >> the room for just a moment and it is frustrating how dark the room is. >> >> Thanks >> >> Barry > >Have you ever thought about using the white light LED-based >light fixtures? They are more efficent than incandescents >and very energy efficent. No they're not. Ordinary incandescents and white LEDs are about equivalent. Quartz-halogen lamps actually beat LEDs by a bit. Only in the very small sizes, flashlight and below, do LEDs have a decided advantage and that is only because small incandescents are so much LESS efficient because of wall and filament mount quenching effects. Here is a table of efficacies that I compiled about a year ago (nothing has changed enough to matter since then): Initial lumens per watt High pressure sodium-- approx 125 (Osram) Low pressure sodium-- 150-180 HID-- 80 to 110 * Automotive D2S 35 watt HID 91 Solarc low wattage HID 45-60 32 watt T8 fluorescent-- 85 to 95 standard F40T12-- 60-65 Tri-phosphor neon-type cold cathode-- 60-80 ** compact fluorescents-- low 30's to low 60's, usually 48-60 Sulfur lamp-- 53 T3 tubular halogen-- 20 white LED-- 15-19 standard 100 watt incandescent-- 17 incandescent night light bulb (7w)-- 6 incandescent flashlight bulbs-- less than 6 * HID lamps and ballast designs vary widely. ** dependent on transformer type and efficiency John From: John De Armond Newsgroups: alt.energy.homepower Subject: Re: CF recommendations Date: Mon, 26 Jun 2006 16:44:04 -0400 Message-ID: <7jg0a2tckm8ocp825o3l6dhajrcen6tpto@4ax.com> On 25 Jun 2006 21:28:12 -0700, walter_lee@my-deja.com wrote: > >In the folllowing webpage that I had previously posted >http://www.smarthome.com/97314a.html >if you click on "details and specifications" >a table will appear, the vendor indicating that this >white light 36 LED 1.3 watt bulb outputs 60 lumen. >at 46.15 lumen/watt > >and at >http://www.theledlight.com/120-VAC-LEDbulbs.html >the vendor says this 36 LED 3.0 watt light bulb >(LYPCB06 CW) outputs 90 lumen/ 3.0 watts >at 30 lumen/watt. Oops, sorry, I forgot that there are people out there who still believe advertising claims. The LED lighting industry is only slightly better than used car salesmen in their lies. Being in the sign business where all types of lighting are used and where a f*ck-up is glaringly visible and financially costly, I don't believe advertising claims. I do believe independent testing from credible third parties such as testing labs, NIST, etc., which is where my numbers came from. LED peddlers stormed the sign biz a few years ago claiming to obsolete all other forms of lighting. Something went wrong on the way to nirvana. They lied. We quickly learned that the efficacy and lifetime figures were numbers that they essentially pulled from their *sses. Even the vaunted Nisha white LEDs would be down to below half their initial brightness after as little as a year of 20/7 operation. Blue LEDs followed closely, followed by green and yellow. Red ones maintain brightness fairly well but only if under-driven significantly. And by the time enough LEDs are packed into a sign to actually equal the brightness of neon, other cold cathode, fluorescents, HID, etc., both the power consumption and heat production is way out of line with what they're supposed to replace. Even though I make neon, I'm not wedded to it. If something better ever does come along I'll gladly use it instead. But I base my decision (and by implication, my business) on independently developed data from credible sources and not advertising claims, no matter how they're re-packaged, and that goes for Wikipedia as well. It should be evident to all but the most dense that places like blacklighting.com and others are simply parroting numbers supplied by others. Of course, since you're just slinging BS on the net you can believe anyone you like. For everyone else, I suggest looking to credible independent sources. Illuminating Engineering Society of North America, International Sign Association, NREL, NIST, etc. Yeah, you usually have to be a member and/or pay for the data but that's life. John |
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