Main > Everything Else

Why is LED lighting still so expensive?

<< < (6/6)

ChadTower:

--- Quote from: Howard_Casto on September 02, 2012, 12:55:23 pm ---Don't take this the wrong way, but I find anybody believing the claims of ANY product coming from the manufacturer to be a little nieve. 

Super glue can't hold elephants across the grand canyon, those strange adds you sometimes get in your email aren't going to make you "perform better", and when a manufacturer gives you a typical lifespan of a product on their box, at least cut it in half.

--- End quote ---




"This light bulb lasts two years" is not exactly "holds an elephant over the grand canyon" when it comes to possibly being true.



SavannahLion:
That's kind of the rub Howard. The vast majority of consumers do not go beyong the initial read over on the packaging. Very few people would know to look at the back and see that the 5 year bulb gets that rating because it was tested for 4 hours each day with the base side down in an air conditioned laboratory.

Is it the consumer's fault for not reading the packaging? Sure. But the manufactures shouldn't need to fudge the numbers. So they're equally to blame.

MonMotha:
I've got a bunch of CFLs I bought back in 2006 that are still going strong.  I've lost one.  Some back of the envelope calculations would suggest it had 4000-5000 hours on it, which I guess is short of the 8000 hours claimed.  These aren't overly fancy either: just GE brand 13W cheapies (receipt says $9.88+tax for a 6 pack) from Wal-Mart.  I've got a 23W from Home Depot I got about a year ago that gets used for almost 8 hours a day essentially daily.  That would be over 2500 hours already on that one.  Still going fine.  Also have some 23W GEs bought around the same time as the 13Ws also from Wal-Mart.  Most probably have 500-1000 hours on them.  They're also still working fine.

I've also had a couple of "100W equivalent" (and they were never that bright, I assure you) from Lowe's that literally lasted maybe 10 hours.  There were, however, very cheap.  OTOH, I have a cheap 23W from Lowe's that has been in my back porch fixture (outside, upside-down, and enclosed) for about 1.5 years and has been frequently left on 24/7 during that time.  I'd estimate ~7200 hours on it.  It still works fine, but, as when it was new, it does take a while to reach full brightness.

Clearly, there's a lot of variability, but if you're replacing your CFLs as often as you were replacing incandescent lamps, you've got crappy power, are buying crummy CFLs, or both.

The CFLs seem to work better (and this would make sense) in open fixtures where the power electronics in the base are oriented down and so not exposed to the heat.  Typical table lamp setup.  Many people report that they don't do nearly as well in recess cans where the heat gets trapped right up against the power electronics in the base.  If you read the fine print, most of the lamps do warn that this may shorten the lifespan.  You can buy ones specifically designed for it, and aside from the typical CFL "complaints" (color spectrum and warm up time, both of which are way better on the higher end lamps), I've not heard major complaints when using them in recess cans and similar.

LED lighting is mostly a diffusion problem with a secondary problem of cooling.  It's not too terribly hard to make a LOT of light from an LED at this point.  The issue is diffusing it so that it doesn't look like a spot lamp (since most people want to replace normal incandescents which are nearly isotropic radiators) and keeping them cool.  LEDs are even less tolerant of high temperature than CFLs.  Fortunately, they also put out a lot less heat, but the small temperature difference between the lamp and ambient can make cooling a challenge.  That's why you see most LED designs are practically a giant heatsink with LEDs mounted in them.

As others have pointed out, a few tweaks to how we do lighting could help a lot.  Indirect lighting is inherently diffusive, so you can build e.g. strips of mid-power LEDs for that, similar to what people have done for lighting using conventional fluorescent tubes in homes.  Most lighting schemes are still designed around incandescent lamps as the only available technology.  You can do some cool stuff with other lighting tech, but you have to break out of the box.

I think good LED light are really more of an optical problem than an electrical one at this point, but the race to the bottom is certainly highlighting how badly you can make an LED lamp if you want to save a buck or two.  Quality power LEDs are still a bit expensive (but getting cheaper every day), and once you add decent optics, power electronics, and a heatsink, $30-50/lamp doesn't seem outrageous provided they do warranty it for the stated lifespan (and no crap about making you pay return shipping, etc.).

MonMotha:

--- Quote from: pinballjim on September 03, 2012, 12:09:51 am ---I've been told that CFLs do well in areas prone to brown outs.  I guess they don't blow immediately if voltage gets weird?

--- End quote ---

Seems quite the opposite, actually.  The ballasts are essentially constant power SMPSes, so in a brown-out, they'll increase their current draw to compensate.  This can burn things up, especially on cheap devices.  Similar problems to an electric motor in a brownout condition.  The recovery transient also oven overshoots and could overvoltage some parts of the supply, and the whole thing will make the regulation feedback loop of the power supply in the lamp have "fun".

Halogen lamps are not banned.  Actually, conventional incandescent isn't either, but it's extremely difficult to hit the mandated efficiency standards with them.  High end halogens do hit the requirement, and they have extremely quality light.  If you absolutely can't stand fluorescent or LED lights, halogens with conventional Edison bases can be a good replacement option.  The light quality should actually be better than what you're used to, and they last 2-3 times as long, too.  Then again, they're also more expensive than the cheapie incandescent lamps were.

Navigation

[0] Message Index

[*] Previous page

Go to full version