19 ms·

That 60W-equivalent LED: What no one will tell you

149 points by Shivetya 13y ago

andrewcooke 13y ago
i'm confused. how can they be efficient if they get hot? are they less efficient than the coiled tubes? if so, why are they an improvement? edit: how can they be more efficient than cfls if they get hotter? how are the cooler cfls wasting energy? you can't just "lose" energy - it has to go somewhere. and normally for losses, it's heat.
- benjamincburns 13y ago
  They're more efficient, not perfectly efficient. Edit to your edit: The amount of heat is actually quite small in comparison to a CFL. The temperature they're talking about is the die temperature. LED dies are tiny, so even though they can reach high temperatures, there's much less heat (waste energy) generated.
  - masklinn 13y ago
    And more problematically, heat severely degrades them (an incandescent bulb will also get extremely hot — as everybody who tried changing a just-blown bulb will know — but for the most part the heat will not significantly degrade it and lower its life expectancy)
    - yardie 13y ago
      Heat does degrade incandescents. The filament eventually vaporizes and as it gets closer to the end of its life it reaches thermal runaway in a split second. Filament resistance goes up because it is evaporating, heat goes up because the filament increases in resistance. I have a 60W bulb I run through a dimmer that is in its 4th year. It is a nightlight for the kid's room so is never really turned off.
      - masklinn 13y ago
        > Heat does degrade incandescents. I didn't say heat didn't degrade incandescents, I said LEDs are much more heavily degraded when they're over their heat capacity.
      - Lagged2Death 13y ago
        Heat is the way incandescents work. If they didn't get hot, they wouldn't make any light. Heat "degrades" them only in the sense that heating them (i.e., turning them on) eventually uses them up. The filament reaches temperatures of 2,000+ degrees C a fraction of a second after it's turned on; the type of fixture the bulb is in won't change the filament temperature much. Filament resistance goes up because it is evaporating, heat goes up because the filament increases in resistance. Higher overall resistance connected to the same voltage produces less current draw and therefore less heat. It's just Ohm's law. The filament doesn't thin out uniformly, it tends to develop localized hotspots which leads to accelerated, localized evaporation. Eventually it breaks. I have a 60W bulb I run through a dimmer that is in its 4th year. You can make an incandescent bulb last an arbitrarily long time if you're willing to sacrifice efficiency by running the filament cooler. A dimmed-down 60W bulb may produce the light of a 5W nightlight bulb but use far more than 5W. The Centennial Light Bulb has lasted a long time, not because it's never turned off, but because it's absolute shit as a light source. The filament stays cool and as a result its both terribly dim and terribly inefficient. http://www.centennialbulb.org/ http://www.centennialbulb.org/
- sean13013 13y ago
  The parts that generate the lion's share of heat in an LED bulb are tiny tiny tiny, and so they can get very hot with much less energy. They generally have chunky heatsinks, but still you can only draw heat away from a point the size of a head of a pin so fast.
- kijin 13y ago
  A regular light bulb converts about 2% of its energy input into light, and 98% into heat. For a 60W light bulb, about 1.25W is converted into light and 58.75W into heat [1]. It's incredibly inefficient, and the filament can reach temperatures of over 3000K. (Ever wonder why CCFL lamps have their colors expressed as temperatures like 2900K? That's the actual temperature of a filament with the same color.) A 60W-equivalent LED lamp uses 6-8W of energy. Assuming it converts roughly the same amount of energy (1.25W) into light, the remaining 4.75-6.75W needs to be converted to heat. That's about as much thermal dissipation as a low-end laptop CPU, but concentrated in a much smaller area and with a much less effective cooling system (it doesn't even have a fan). 85 degrees sounds about right. [Edit] Still, 85 degrees is nothing compared to the extreme temperatures that a filament in a regular light bulb experiences. It's only a problem because the LED chips aren't made of carbon or tungsten like filaments are. [1] https://en.wikipedia.org/wiki/Incandescent_light_bulb#Efficacy.2C_efficiency.2C_and_environmental_impact https://en.wikipedia.org/wiki/Incandescent_light_bulb#Effica...
  - andrewcooke 13y ago
    i'm not comparing LEDs with incadescent bulbs, i'm comparing them with the coiled tubes - cfls. these things - http://en.wikipedia.org/wiki/Compact_fluorescent_lamp http://en.wikipedia.org/wiki/Compact_fluorescent_lamp [i thought that was obvious - are you trolling?]
    - kijin 13y ago
      I was just trying to explain how even an "efficient" lamp can overheat. Sorry I overlooked the CFL. In terms of energy efficiency, CFLs are halfway between incandescent bulbs and LEDs. So the same comparison holds, only the differences are less extreme. 60W-equivalent CFLs use 13-15W of energy. That's approx. 1.25W into light (because the amount of light is more or less the same in all cases) and the remainder (11.75-13.75W) into heat. That's why CFL lamps get rather warm after a while. Very bright CFLs often have slots in the base for ventilation [1]. You just don't notice it as much because: 1) The heat source of CFLs is much larger than LEDs, so the average temperature is lower even though the total amount of heat is higher. 2) With all those coils and folds, CFLs have a larger surface area than most other types of lamps, so they cool easily. [1] https://en.wikipedia.org/wiki/File:Compact_fluorescent_light_bulbs_105W_36W_11W.jpg https://en.wikipedia.org/wiki/File:Compact_fluorescent_light...
- ars 13y ago
  > how can they be more efficient than cfls They are not more efficient than CFLs. It is interesting that you think they are - I guess the marketing is working. Now, you might come across some LEDs that on the surface appear to be more efficient, but actually they are misleading you. Those efficient LEDs have worse color accuracy than CFLs, so you are not comparing equivalent products. LEDs do have room to improve, so they may get more efficient than CFLs, but they are not there yet.
- jcampbell1 13y ago
  CFL's also get hot, but the heat is on the coiled glass tube, so the heat and light radiate from the same place. Because the coil is the radiator, they ventilate heat naturally. In order to trap the heat in a CFL, you would need to design a fixture that doesn't let light out. The problem with LEDs, is you need a metal radiator positioned to not block the light. In a recessed fixture, the heat can get trapped.
- Florin_Andrei 13y ago
  They don't get "hotter" overall. The problem with LEDs is that most of that waste heat is produced in a tiny element - the actual LED chip - which is difficult to cool down because you can't surround it completely with heat sinks. The meager heat sinks you can put on the back of the chip are not so well connected thermally with the environment. A CFL has a much larger volume to produce that heat, and a much larger surface area to radiate it; and even if it got very hot it wouldn't care that much. A LED is a tiny speck of semiconductor that bears the brunt of a lot of energy, and it's not rated for operating at high temperature. It's like normal sunlight warming up the palm of your hand versus sunlight focused to a point by a palm-size loupe - it's the same total energy, but one is nice and warm whereas the other can cause serious damage.
- pwg 13y ago
  > i'm confused. how can they be efficient if they get hot? The reason is due to the balance between heat generated and heat dissipated into the environment. The bulb could convert 99% of the input electrical energy into light, and only 1% into heat. So for a 100W bulb, that would be only 1 watt of heat. But if the heat dissipation system (i.e., the cooling system) can only dissipate 1/2 watt of heat into the environment over the same time span that the bulb is creating 1 watt of heat, the excess 1/2 watt of undissipated heat will build up over time, making the housing hot to the touch.
Benferhat 13y ago
tl;dr: LED bulbs get too hot, lowering their life expectancy. Manufacturers need to include cheap thermistor circuits, which automatically dim the light to a safe thermal equilibrium.
- benjamincburns 13y ago
  Consumers need to be educated, too. Anyone using an A19 in a can-style fixture is wasting energy by lighting things they don't need lit. Use something directional like a PAR or a BR, and you can reduce the amount of wattage consumed to light a given area. Further, LED manufacturers design their directional lamps with these applications in mind. See the spiral pattern [1] on the heat sink around Lighting Science PAR bulbs? That's designed to use the thermal differential to create a nice air flow up into the fixture so that it may be used in a recessed or other partially-enclosed fixture. 1: http://www.1000bulbs.com/product/100560/LED-PAR3011HE25WW.html http://www.1000bulbs.com/product/100560/LED-PAR3011HE25WW.ht...
  - Lightbody 13y ago
    It's not that simple, sadly. My house has 100+ canned recessed lights, all of which had been filled with Sylvania 50W Halogen PAR30 & PAR30LN bulbs. I have been desperately trying to find a replacement LED that matches the same warmth and color. This bulb claims to be the exact replacement: http://www.amazon.com/gp/product/B00467E3LA/ http://www.amazon.com/gp/product/B00467E3LA/ But yet this one and others that have similar lumens, temperature, and equivalent watts all don't even get close to the warmth that the halogens produced. Fortunately, I found a cheap alternative: http://www.amazon.com/Philips-424374-7-watt-Household-Dimmable/dp/B00B4CPLGG/ http://www.amazon.com/Philips-424374-7-watt-Household-Dimmab... It's the A19 40W that the article cautions against, and it looks slightly less sexy in the recessed can, but the color almost exactly matches the halogens I have (except when dimmed -- nothing can match the fireplace-like glow). What's weird is that the lumens and temperature for that bulb aren't even close to what the halogens claim, but they look almost identical. Which has made me wonder if this switch to LED is way more complex than just those two measurements :P
tonylemesmer 13y ago
If the thermister circuit is installed they'll be dimmer. Either way, the customer is still disappointed. Shorter life or dimmer bulb, depends which the customer is more concerned about. Adding the circuit changes nothing.
TheCraiggers 13y ago
Not all LED lightbulbs are created equal. I've been watching some guy on Youtube do various teardowns and tests on various brands, and it's been enlightening. His channel is at http://www.youtube.com/user/electronupdate http://www.youtube.com/user/electronupdate Also, isn't the phrase "What you don't know, and no one will tell you" oxymoronic? I suppose "what you don't know, and only I will tell you" doesn't have the same ring to it.
- benjamincburns 13y ago
  Well there goes my day... Thanks for posting that link!
  - InclinedPlane 13y ago
    While you're at it: http://www.youtube.com/user/bkraz333 http://www.youtube.com/user/bkraz333 http://www.youtube.com/user/eevblog http://www.youtube.com/user/eevblog http://www.youtube.com/user/Afrotechmods http://www.youtube.com/user/Afrotechmods
- tracker1 13y ago
  It's fairly obvious, that you and the guy that runs the channel in question are witches... prepare to burn! Seriously though, this is pretty cool... I am fairly surprised that there hasn't been a DC standard for lighting fixtures come into play yet... Which could be much more effective in terms of cost over time, and temperature control. Given the shear number of wall warts, and other fixtures common in the home, it would make sense for a more common interface for DC (especially low watt)... USB seems to be becoming that standard, but for lighting, and safety for internal wiring a new standard is probably needed (or an old one revisited).
  - Osiris 13y ago
    Given that nearly everything in a home uses AC-DC converters, I'm also really surprised that there isn't (that I know) a standard for a whole house DC jack that can supply common DC voltages, removing the necessity for all devices to have their own AC-DC transformers.
JackFr 13y ago
This read to me like an ad for CFL's. Real shortcomings of CFL's are dismissed with a hand wave, while LED's get the full local news style sensationalism: "Are your LED bulbs killing you? Story at 10."
- gagege 13y ago
  Nah, I didn't read it that way at all. The article clearly states, several times, that LEDs consume less power and that there are better LEDs out there. Also, the article basically equates CFL and incandescent bulbs. If they were trying to sell CFLs why would they do that?
- colanderman 13y ago
  It gives a simple design enhancement for LED bulbs at the end of the article to fix the problem outlined. So I think not.
- dfc 13y ago
  Or it reads like an advertisement for thermal management technology inside of LED light bulbs: "Ed Rodriguez [the author]...formed OptoThermal Technologies to focus on thermal management technologies related to high-power LED lighting." http://www.edn.com/user/ed%20ro http://www.edn.com/user/ed%20ro
ams6110 13y ago
Thanks for the warning. Time to restock my cache of incandescents, before they are completely unavailable anymore.
- carlob 13y ago
  No need to do that, you can still use CFL and they are not being phased out.
  - maw 13y ago
    Why would anybody want to use CFL? Is it more for the migraines or for how they make everything look sickly?
    - ars 13y ago
      CFLs don't flicker anymore, and if color accuracy is what you want stay away from LEDs since all the efficient ones are worse than CFLs. You can make LEDs with good color accuracy but you lose efficiency making them worse than equivalent CFLs.
    - outworlder 13y ago
      There are several types of fluorescent lighting, with different color temperatures. Granted, their spectra is not the same as sunlight, but you can mix more than one type for a more pleasant effect.
    - code_duck 13y ago
      We enjoy smelling the flame retardant fumes offgassing from the electronics. Bonus when one burns out in a small cloud of acrid plastic smoke.
  - _red 13y ago
    What if you don't want to deal with the toxic mercury gases?
    - outworlder 13y ago
Pxtl 13y ago
IANAL, but it sounds like there are a dozen class-action lawsuits waiting to happen here. Consumers have the reasonable expectation that a light bulb reach something vaguely approaching its promised useful life in any fixture that is supposedly compatible with it.
- deleted 13y ago
  [deleted]
- maxerickson 13y ago
  This mentality says that you can't put a screw base on some technology that you can easily say is not for use in enclosed fixtures. In some sense, I think you are arguing that your oven should be compatible with gasoline (cause hey, you can put gasoline in a container that will fit in an oven). Of course you aren't, I just think you are probably headed too far in that direction. I guess I'm willing to make consumers do more than make sure they fit together.
lotsofcows 13y ago
Oxymoronic titles ftw!
Hermel 13y ago
Also, regardless of what it says on the package, the light won't be as warm as that of a classical light bulb. For a cosy light, you need to get a classical bulb or halogen.
nodata 13y ago
So is there a table of which manufacturers use thermistors?
ajcarpy2005 13y ago
It looks like we're gonna need some innovations in light fixtures which have better heat flow/sinks.
dangrossman 13y ago
I have dozens of Cree-brand LED bulbs in my home (they're the uber-cheap brand Home Depot carries, yet always very favorably reviewed). Their packaging carries no warnings against use in totally enclosed fixtures, and I have several in such fixtures in bathrooms. They also come with a 10-year full replacement warranty. Some are now about two years old, and none of their bulbs have failed or even become too hot to touch. I have a feeling this guy's overstating the problem. Perhaps because he's in the business of patenting thermal protection designs for bulb manufacturers.
- Shivetya 13y ago
  its not the bulb that gets warm, after having one on awhile take it out of the fixture and check the base of it. I have two in tulip style fixtures where the bulbs point down, they don't last long but receipts are a wonderful thing. Eventually I think the big box store I get them from will change their return rules
  - jamesaguilar 13y ago
    As long as they have a ten-year replacement guarantee, I guess it doesn't matter as long as it's not a fire hazard.
    - ScottBurson 13y ago
      Fire hazard? They're certainly not as hot as incandescent bulbs!
      - jamesaguilar 13y ago
        Sorry, I simply didn't know. I did not mean to imply they were.
  - loginx 13y ago
    I've noticed the opposite pattern in my house. Ever since we bought the place, we noticed that occasionally we would semi-randomly get a very fishy smell coming out of our staircase, and couldn't find the cause. After putting my google-fu to use, I realized it was the plastic casing of a small light fixture in the staircase that was getting very hot and slowly melting around the incandescent bulb. I've replaced the bulb with an LED bulb several months ago and I've checked the base of the socket, the fixture, and the bulb after hours of use, and all three are barely warm to the touch at all. I suppose it may depend on manufacturing quality, or as the OP article mentions, airflow.
refurb 13y ago
Wow! I actually liked this article. Taught me something I don't know, made a nice factual argument without using hyperbole. A great example of the kind of article we should see more of on HN.
tytso 13y ago
There are some LED bulbs that are explicitly rated for use in enclosures with no ventilation. The other thing to pay attention to is whether the light dispersal pattern is pointed mostly straight down (i.e., for a recessed ceiling lighting fixure) or omni-directional (i.e., for a sconce or a table lamp). Reputable stores will make this clear --- and yes, it's a bit more complicated than just grabbing a random 100W incandescent bulb. For example: http://store.earthled.com/collections/led-light-bulbs-suitable-for-enclosed-fixtures-fully-enclosed-fixture-rated-led-light-bulbs http://store.earthled.com/collections/led-light-bulbs-suitab...
- cjensen 13y ago
  The point of the linked article is the bulb will not last very long when hot. The article never said it wouldn't work.
  - adestefan 13y ago
    No bulb will last very long when hot. This isn't something new.
    - ars_technician 13y ago
      Incandescents will. They get very hot in normal operation and last the amount of time you would expect from an incandescent.
      - Filligree 13y ago
        Which is not, by any stretch of the imagination, "very long".
        DanBC 13y ago
        Incandescents die from thermal shock, not from being hot.
        13y ago
grogenaut 13y ago
Don't Bury the Lead Dude. I've seen senate reports that take less time to get to the point about safety warnings. TL;DR: Many leds aren't meant to be in unventilated can fixtures and will either burn themselves up, reduce lifetime, or worse start fires. At least that's what I think I got out what was mainly a lot of talk about other types of bulbs.
- vacri 13y ago
  Given this topic, I would have gone for the alternate spelling in 'don't bury the lead'...
  - grogenaut 13y ago
    don't burly the lead?
    - vacri 13y ago
      'lede'
pkulak 13y ago
I still have no idea why an led bulb is better than CFL for home lighting. From what I can tell, people just like new stuff.
- dangrossman 13y ago
  > I still have no idea why an led bulb is better than CFL for home lighting * They use 30-40% less power, costing you less to operate * Cheap CFLs commonly had ballasts that died in 1-3 years despite higher life expectancy claims on the packages; LEDs are backed with 10+ year warranties * CFLs burn out quickly if used in fixtures that are turned on and off frequently * LEDs don't flicker/strobe like fluorescent lighting * Virtually all LED bulbs work in dimmers, not just more expensive specialty ones * Cheap LED bulbs don't produce bluish light like cheap CFL bulbs
  - mrgriscom 13y ago
    and they rise to full brightness immediately... and they're indestructible... and they're not filled with mercury...
    - vacri 13y ago
      To be honest, I like my bathroom light to wake up alongside me in the morning.
    - pilom 13y ago
      An CFL bulb has less mercury in it than a can of tuna: http://www.lamprecycle.org/public/images/docs/LD+A%20August%202009.pdf http://www.lamprecycle.org/public/images/docs/LD+A%20August%...
    - OneOneOneOne 13y ago
      Exactly. With small children in the house this is a good thing. I use them in torch style lamps to save energy and not break when tipped over. With incandescent bulbs I was also concerned with electric shock from broken bulb, cuts and burns... though I wonder if the LED bulb would be a fire hazard if it were to rest on something.
deleted 13y ago
[deleted]
jwr 13y ago
I've spent a lot of time recently working on my own LED lamp designs. Heat dissipation is indeed the biggest problem, the second being the cost and complexity of interfacing to an AC network of 230/110V. I think new kinds of fixtures will need to be designed, as well as new standards for DC distribution within the house (I am trying out 48V and 24V). Retrofitting existing infrastructure with LEDs makes no sense: we get wasteful, fragile and inefficient systems.
- kalleboo 13y ago
  > as well as new standards for DC distribution within the house (I am trying out 48V and 24V). This is something I've wondered about for a while. Everything in my home aside from a few kitchen appliances is now running a AC<>DC converter. At what point does it make more sense to run DC circuits in the home? Would the gauge be a problem to run enough DC power for a desktop PC, a TV, and a ton of LED lights?
  - jwr 13y ago
    I think you need to strike a certain balance: for longer stretches of wire and higher wattage AC will work better. What doesn't make sense is building tiny switching power supplies into every lightbulb. I was planning to use a power supply for every group of lights — e.g. one for the ceiling, one for under-cabinet lighting, etc. That way you don't have to run long stretches of wire with DC, and yet you don't have to build lots of tiny low-efficiency converters.
    - kalleboo 13y ago
      For lighting-only, IKEA sells a mix-and-match LED system where you can connect 10 different units to a single power supply (units being various LED strips, spotlights, etc), with varying lengths of extension cords (up to 2m I believe).
- Perseids 13y ago
  > Retrofitting existing infrastructure with LEDs makes no sense: we get wasteful, fragile and inefficient systems. I wholeheartedly agree and would go even further and reimagine our current illumination concepts. At the moment we mostly have a few powerful point light sources. Given the longevity of LEDs we could easily design walls and furnitures with hundreds of less powerful LEDs that would produce a much more even illumination, have far less problems with head dissipation and be cheaper to produce than those high luminosity LEDs. And even more interesting, this would open the door to far more creative designs than we have now. With OLEDs you could even have glowing wallpapers: http://oled-werbedisplays.de/wp-content/uploads/2013/02/oled-wallpaper.jpg http://oled-werbedisplays.de/wp-content/uploads/2013/02/oled...
Zoomla 13y ago
They also currently take much more energy to manufacture then an incandescent bulb.
nickhalfasleep 13y ago
What a bullshit dataless fearmongering article. If your lamp and enclosure are UL rated then the on-die temperature is well within operating parameters for the 6000 hr+ lifespan. If you go with a CREE or Philips lamp then their thermal design was built for the cooking the L-Prize and Energy Star demands of them. The DOE took their and customer experiences with CFL's to heart when designing goals for Energy Star LED lamps. Source: I was a lighting engineer at a major Independent Testing Laboratory for 5 years before going to software full time.
- nickhalfasleep 13y ago
  In short, get only Energy Star certified lamps http://www.energystar.gov/index.cfm?c=ssl.pr_why_es_com http://www.energystar.gov/index.cfm?c=ssl.pr_why_es_com To get the Energy Star rating, the manufacturer must get an independent lab to measure their operation at 45C and measure the temperature on the die (per the LED manufacturer's specs), to validate that it will maintain it's life expectancy. http://www.energystar.gov/ia/partners/manuf_res/downloads/IntegralLampsFINAL.pdf http://www.energystar.gov/ia/partners/manuf_res/downloads/In... If you want to read all the nitty gritty details.
  - mcguire 13y ago
    "the manufacturer must get an independent lab to measure their operation at 45C and measure the temperature on the die" In an environment with no airflow?
    - nickhalfasleep 13y ago
      There is convection off of the bulb, but no flow from any other source. They want to make sure they can sit and take it.
      - mcguire 13y ago
        That might be a problem, if the bulb was installed in a recessed ceiling can, right? Convection would heat the environment in the fixture.
stcredzero 13y ago
Aren't we hobbled by the legacy interfaces for light bulbs, in much the same way that SATA isn't necessarily the best interface for flash SSDs? LEDs are a different thing. It seems like lamps that use them should have thermal management built into them. The increase in surface area would make thermal management much easier.
- magnawave 13y ago
  Yes this is exactly the problem - less so with CFL but hugely so with LED. LEDs should appear as a part of the fixture itself - not as a screw in replacement for the legacy Edison socket. I suspect this will happen eventually when people start to see all the cool lighting options you have with LED fixtures - but its going to take a good while to get the mental shift to happen!
ubercore 13y ago
I really dislike this article. It took me a little bit to figure out why. Most of the annoyance comes from fatigue of reading this kind of thing. "Humvees are more carbon neutral than a Prius" kind of thing. Besides my personal annoyance though, this kind of unbalanced and unrigorous article is just flat out dangerous to public discourse on a pretty important issue. LED bulbs have strengths and weakness, to be sure. I didn't think the heat issue was a "secret" that "nobody will tell me". It was the first thing mentioned in nearly every single article or story I've seen about LED bulbs. I've been using LED bulbs for about 4 years now (in regular fixtures, closed fixtures, outdoor fixtures in summer and winter, closed bathroom fixtures) and have not had a single issue. As others mention, even if I did there's good warranty coverage. I'm probably more radical than most on energy issues, but I find this kind of FUD downright irresponsible. It also is part of this annoying trend of people that really enjoy trying to poke holes in new technology. Like electrocuting elephants with evil electric distribution technology.
- hyperpape 13y ago
  In mild support of your comment: I haven't bought any LEDs yet. I found out that they had reached practicality when I saw a display in Home Depot a few months ago (last I'd heard was years ago, that they were too expensive). Yet I still managed to hear that you can't use them in enclosures. I can't even remember where: it might have been some guys talking at the office. I'm sure that there are people out there who don't know this, but it also seems like it's approaching common knowledge.
- maratd 13y ago
  > I'm probably more radical than most on energy issues, but I find this kind of FUD downright irresponsible. FUD? Seems like common sense to me. If something comes with a heat sink, it's to disperse heat. If you're dispersing heat, you need airflow. I know this. You know this. But the average consumer does not. Consumers should be aware of this and this article accomplishes that. Please keep any fanatical environmentalism to a minimum. Nobody is saying LEDs are bad. I own quite a few. It is, however, important to know how to use them effectively.
  - 13y ago
Spooky23 13y ago
The whole lightbulb debacle is a great reason why the government regulatory regime needs to stop meddling with the marketplace. Until 2000, buying a lightbulb was an unconscious act. You go to any store, and buy a fucking lightbulb. 80% of sales were 60w. Some applications call for different bulbs. Now, solutions for getting light out of edison sockets take up A FULL AISLE in Home Depot, with a dizzying array of choices that are difficult to evaluate. You can buy normal lightbulbs, except that now most of them are mislabeled -- a 60W bulb may actually be 50W. 100W bulbs are impossible to find and cost $5/ea. You can buy CFLs. Some are great, others make your living room look like a gas station bathroom in 1960. Most suck, and as a layman, I now have to know what color temperature is. And, oh yeah, many bulbs, which cost 5x-10x the original bulbs, burn out quickly in fixtures, or burn out quickly when in any orientation other than a standard lamp. (ie. put them in sideways, or mount them upside down) Now you have LEDs, which sometimes have better light quality, but they cost $20. And while they may last longer, you need to be an engineer to evaluate the appropriate bulb for the appropriate application. Just let me buy a bulb and pay more for electricity.
- jonknee 13y ago
  > Now, solutions for getting light out of edison sockets take up A FULL AISLE in Home Depot, with a dizzying array of choices that are difficult to evaluate. So that damn government meddling has resulted in too much choice in the free market?
  - Spooky23 13y ago
    No, it's resulted in a bunch of subpar choices by largely eliminating the best choice from a qualitative perspective. The government decided that modifying the electricity demand curve was more important than me having light that meets my needs when the sun goes down. A free market approach would allow me to make decisions based on cost and other factors. For example, my basement and garage are lit by efficient CFL and very expensive LED lighting that was installed when the house was purchased several years ago. In my office, I find a standard incandescent bulb better than the more efficient alternatives. I value not getting a headache every evening more highly than the $8 I spend in electricity annually on those bulbs. So now I have to resort to hoarding light-bulbs. I'm an engineer passionate about efficiency, so I tweak stuff like this. My mom isn't -- she ends up suffering with awful light.
mistercow 13y ago
It seems like the obvious solution to this is to actively increase airflow. Small fans or synthetic jets could be included on the bulbs themselves, although this would be tricky to do compactly, especially for fans. Alternatively, they could be built into light fixtures designed specifically for LED bulbs, which would be less expensive overall, and would allow the cooling to be designed for the specific fixture (face up vs. face down, for example).

149 points by Shivetya 13y ago

i'm confused. how can they be efficient if they get hot? are they less efficient than the coiled tubes? if so, why are they an improvement? edit: how can they be more efficient than cfls if they get hotter? how are the cooler cfls wasting energy? you can't just "lose" energy - it has to go somewhere. and normally for losses, it's heat.

benjamincburns 13y ago
They're more efficient, not perfectly efficient. Edit to your edit: The amount of heat is actually quite small in comparison to a CFL. The temperature they're talking about is the die temperature. LED dies are tiny, so even though they can reach high temperatures, there's much less heat (waste energy) generated.
- masklinn 13y ago
  And more problematically, heat severely degrades them (an incandescent bulb will also get extremely hot — as everybody who tried changing a just-blown bulb will know — but for the most part the heat will not significantly degrade it and lower its life expectancy)
  - yardie 13y ago
    Heat does degrade incandescents. The filament eventually vaporizes and as it gets closer to the end of its life it reaches thermal runaway in a split second. Filament resistance goes up because it is evaporating, heat goes up because the filament increases in resistance. I have a 60W bulb I run through a dimmer that is in its 4th year. It is a nightlight for the kid's room so is never really turned off.
    - masklinn 13y ago
      > Heat does degrade incandescents. I didn't say heat didn't degrade incandescents, I said LEDs are much more heavily degraded when they're over their heat capacity.
    - Lagged2Death 13y ago
      Heat is the way incandescents work. If they didn't get hot, they wouldn't make any light. Heat "degrades" them only in the sense that heating them (i.e., turning them on) eventually uses them up. The filament reaches temperatures of 2,000+ degrees C a fraction of a second after it's turned on; the type of fixture the bulb is in won't change the filament temperature much. Filament resistance goes up because it is evaporating, heat goes up because the filament increases in resistance. Higher overall resistance connected to the same voltage produces less current draw and therefore less heat. It's just Ohm's law. The filament doesn't thin out uniformly, it tends to develop localized hotspots which leads to accelerated, localized evaporation. Eventually it breaks. I have a 60W bulb I run through a dimmer that is in its 4th year. You can make an incandescent bulb last an arbitrarily long time if you're willing to sacrifice efficiency by running the filament cooler. A dimmed-down 60W bulb may produce the light of a 5W nightlight bulb but use far more than 5W. The Centennial Light Bulb has lasted a long time, not because it's never turned off, but because it's absolute shit as a light source. The filament stays cool and as a result its both terribly dim and terribly inefficient. http://www.centennialbulb.org/ http://www.centennialbulb.org/
sean13013 13y ago
The parts that generate the lion's share of heat in an LED bulb are tiny tiny tiny, and so they can get very hot with much less energy. They generally have chunky heatsinks, but still you can only draw heat away from a point the size of a head of a pin so fast.
kijin 13y ago
A regular light bulb converts about 2% of its energy input into light, and 98% into heat. For a 60W light bulb, about 1.25W is converted into light and 58.75W into heat [1]. It's incredibly inefficient, and the filament can reach temperatures of over 3000K. (Ever wonder why CCFL lamps have their colors expressed as temperatures like 2900K? That's the actual temperature of a filament with the same color.) A 60W-equivalent LED lamp uses 6-8W of energy. Assuming it converts roughly the same amount of energy (1.25W) into light, the remaining 4.75-6.75W needs to be converted to heat. That's about as much thermal dissipation as a low-end laptop CPU, but concentrated in a much smaller area and with a much less effective cooling system (it doesn't even have a fan). 85 degrees sounds about right. [Edit] Still, 85 degrees is nothing compared to the extreme temperatures that a filament in a regular light bulb experiences. It's only a problem because the LED chips aren't made of carbon or tungsten like filaments are. [1] https://en.wikipedia.org/wiki/Incandescent_light_bulb#Efficacy.2C_efficiency.2C_and_environmental_impact https://en.wikipedia.org/wiki/Incandescent_light_bulb#Effica...
- andrewcooke 13y ago
  i'm not comparing LEDs with incadescent bulbs, i'm comparing them with the coiled tubes - cfls. these things - http://en.wikipedia.org/wiki/Compact_fluorescent_lamp http://en.wikipedia.org/wiki/Compact_fluorescent_lamp [i thought that was obvious - are you trolling?]
  - kijin 13y ago
    I was just trying to explain how even an "efficient" lamp can overheat. Sorry I overlooked the CFL. In terms of energy efficiency, CFLs are halfway between incandescent bulbs and LEDs. So the same comparison holds, only the differences are less extreme. 60W-equivalent CFLs use 13-15W of energy. That's approx. 1.25W into light (because the amount of light is more or less the same in all cases) and the remainder (11.75-13.75W) into heat. That's why CFL lamps get rather warm after a while. Very bright CFLs often have slots in the base for ventilation [1]. You just don't notice it as much because: 1) The heat source of CFLs is much larger than LEDs, so the average temperature is lower even though the total amount of heat is higher. 2) With all those coils and folds, CFLs have a larger surface area than most other types of lamps, so they cool easily. [1] https://en.wikipedia.org/wiki/File:Compact_fluorescent_light_bulbs_105W_36W_11W.jpg https://en.wikipedia.org/wiki/File:Compact_fluorescent_light...
ars 13y ago
> how can they be more efficient than cfls They are not more efficient than CFLs. It is interesting that you think they are - I guess the marketing is working. Now, you might come across some LEDs that on the surface appear to be more efficient, but actually they are misleading you. Those efficient LEDs have worse color accuracy than CFLs, so you are not comparing equivalent products. LEDs do have room to improve, so they may get more efficient than CFLs, but they are not there yet.
jcampbell1 13y ago
CFL's also get hot, but the heat is on the coiled glass tube, so the heat and light radiate from the same place. Because the coil is the radiator, they ventilate heat naturally. In order to trap the heat in a CFL, you would need to design a fixture that doesn't let light out. The problem with LEDs, is you need a metal radiator positioned to not block the light. In a recessed fixture, the heat can get trapped.
Florin_Andrei 13y ago
They don't get "hotter" overall. The problem with LEDs is that most of that waste heat is produced in a tiny element - the actual LED chip - which is difficult to cool down because you can't surround it completely with heat sinks. The meager heat sinks you can put on the back of the chip are not so well connected thermally with the environment. A CFL has a much larger volume to produce that heat, and a much larger surface area to radiate it; and even if it got very hot it wouldn't care that much. A LED is a tiny speck of semiconductor that bears the brunt of a lot of energy, and it's not rated for operating at high temperature. It's like normal sunlight warming up the palm of your hand versus sunlight focused to a point by a palm-size loupe - it's the same total energy, but one is nice and warm whereas the other can cause serious damage.
pwg 13y ago
> i'm confused. how can they be efficient if they get hot? The reason is due to the balance between heat generated and heat dissipated into the environment. The bulb could convert 99% of the input electrical energy into light, and only 1% into heat. So for a 100W bulb, that would be only 1 watt of heat. But if the heat dissipation system (i.e., the cooling system) can only dissipate 1/2 watt of heat into the environment over the same time span that the bulb is creating 1 watt of heat, the excess 1/2 watt of undissipated heat will build up over time, making the housing hot to the touch.

Benferhat 13y ago

tl;dr: LED bulbs get too hot, lowering their life expectancy. Manufacturers need to include cheap thermistor circuits, which automatically dim the light to a safe thermal equilibrium.

benjamincburns 13y ago
Consumers need to be educated, too. Anyone using an A19 in a can-style fixture is wasting energy by lighting things they don't need lit. Use something directional like a PAR or a BR, and you can reduce the amount of wattage consumed to light a given area. Further, LED manufacturers design their directional lamps with these applications in mind. See the spiral pattern [1] on the heat sink around Lighting Science PAR bulbs? That's designed to use the thermal differential to create a nice air flow up into the fixture so that it may be used in a recessed or other partially-enclosed fixture. 1: http://www.1000bulbs.com/product/100560/LED-PAR3011HE25WW.html http://www.1000bulbs.com/product/100560/LED-PAR3011HE25WW.ht...
- Lightbody 13y ago
  It's not that simple, sadly. My house has 100+ canned recessed lights, all of which had been filled with Sylvania 50W Halogen PAR30 & PAR30LN bulbs. I have been desperately trying to find a replacement LED that matches the same warmth and color. This bulb claims to be the exact replacement: http://www.amazon.com/gp/product/B00467E3LA/ http://www.amazon.com/gp/product/B00467E3LA/ But yet this one and others that have similar lumens, temperature, and equivalent watts all don't even get close to the warmth that the halogens produced. Fortunately, I found a cheap alternative: http://www.amazon.com/Philips-424374-7-watt-Household-Dimmable/dp/B00B4CPLGG/ http://www.amazon.com/Philips-424374-7-watt-Household-Dimmab... It's the A19 40W that the article cautions against, and it looks slightly less sexy in the recessed can, but the color almost exactly matches the halogens I have (except when dimmed -- nothing can match the fireplace-like glow). What's weird is that the lumens and temperature for that bulb aren't even close to what the halogens claim, but they look almost identical. Which has made me wonder if this switch to LED is way more complex than just those two measurements :P

tonylemesmer 13y ago

If the thermister circuit is installed they'll be dimmer. Either way, the customer is still disappointed. Shorter life or dimmer bulb, depends which the customer is more concerned about. Adding the circuit changes nothing.

TheCraiggers 13y ago

Not all LED lightbulbs are created equal. I've been watching some guy on Youtube do various teardowns and tests on various brands, and it's been enlightening. His channel is at http://www.youtube.com/user/electronupdate http://www.youtube.com/user/electronupdate Also, isn't the phrase "What you don't know, and no one will tell you" oxymoronic? I suppose "what you don't know, and only I will tell you" doesn't have the same ring to it.

benjamincburns 13y ago
Well there goes my day... Thanks for posting that link!
- InclinedPlane 13y ago
  While you're at it: http://www.youtube.com/user/bkraz333 http://www.youtube.com/user/bkraz333 http://www.youtube.com/user/eevblog http://www.youtube.com/user/eevblog http://www.youtube.com/user/Afrotechmods http://www.youtube.com/user/Afrotechmods
tracker1 13y ago
It's fairly obvious, that you and the guy that runs the channel in question are witches... prepare to burn! Seriously though, this is pretty cool... I am fairly surprised that there hasn't been a DC standard for lighting fixtures come into play yet... Which could be much more effective in terms of cost over time, and temperature control. Given the shear number of wall warts, and other fixtures common in the home, it would make sense for a more common interface for DC (especially low watt)... USB seems to be becoming that standard, but for lighting, and safety for internal wiring a new standard is probably needed (or an old one revisited).
- Osiris 13y ago
  Given that nearly everything in a home uses AC-DC converters, I'm also really surprised that there isn't (that I know) a standard for a whole house DC jack that can supply common DC voltages, removing the necessity for all devices to have their own AC-DC transformers.

JackFr 13y ago

This read to me like an ad for CFL's. Real shortcomings of CFL's are dismissed with a hand wave, while LED's get the full local news style sensationalism: "Are your LED bulbs killing you? Story at 10."

gagege 13y ago
Nah, I didn't read it that way at all. The article clearly states, several times, that LEDs consume less power and that there are better LEDs out there. Also, the article basically equates CFL and incandescent bulbs. If they were trying to sell CFLs why would they do that?
colanderman 13y ago
It gives a simple design enhancement for LED bulbs at the end of the article to fix the problem outlined. So I think not.
dfc 13y ago
Or it reads like an advertisement for thermal management technology inside of LED light bulbs: "Ed Rodriguez [the author]...formed OptoThermal Technologies to focus on thermal management technologies related to high-power LED lighting." http://www.edn.com/user/ed%20ro http://www.edn.com/user/ed%20ro

ams6110 13y ago

Thanks for the warning. Time to restock my cache of incandescents, before they are completely unavailable anymore.

carlob 13y ago
No need to do that, you can still use CFL and they are not being phased out.
- maw 13y ago
  Why would anybody want to use CFL? Is it more for the migraines or for how they make everything look sickly?
  - ars 13y ago
    CFLs don't flicker anymore, and if color accuracy is what you want stay away from LEDs since all the efficient ones are worse than CFLs. You can make LEDs with good color accuracy but you lose efficiency making them worse than equivalent CFLs.
  - outworlder 13y ago
    There are several types of fluorescent lighting, with different color temperatures. Granted, their spectra is not the same as sunlight, but you can mix more than one type for a more pleasant effect.
  - code_duck 13y ago
    We enjoy smelling the flame retardant fumes offgassing from the electronics. Bonus when one burns out in a small cloud of acrid plastic smoke.
- _red 13y ago
  What if you don't want to deal with the toxic mercury gases?
  - outworlder 13y ago

Pxtl 13y ago

IANAL, but it sounds like there are a dozen class-action lawsuits waiting to happen here. Consumers have the reasonable expectation that a light bulb reach something vaguely approaching its promised useful life in any fixture that is supposedly compatible with it.

deleted 13y ago
[deleted]
maxerickson 13y ago
This mentality says that you can't put a screw base on some technology that you can easily say is not for use in enclosed fixtures. In some sense, I think you are arguing that your oven should be compatible with gasoline (cause hey, you can put gasoline in a container that will fit in an oven). Of course you aren't, I just think you are probably headed too far in that direction. I guess I'm willing to make consumers do more than make sure they fit together.

lotsofcows 13y ago

Oxymoronic titles ftw!

Hermel 13y ago

Also, regardless of what it says on the package, the light won't be as warm as that of a classical light bulb. For a cosy light, you need to get a classical bulb or halogen.

nodata 13y ago

So is there a table of which manufacturers use thermistors?

ajcarpy2005 13y ago

It looks like we're gonna need some innovations in light fixtures which have better heat flow/sinks.

dangrossman 13y ago

I have dozens of Cree-brand LED bulbs in my home (they're the uber-cheap brand Home Depot carries, yet always very favorably reviewed). Their packaging carries no warnings against use in totally enclosed fixtures, and I have several in such fixtures in bathrooms. They also come with a 10-year full replacement warranty. Some are now about two years old, and none of their bulbs have failed or even become too hot to touch. I have a feeling this guy's overstating the problem. Perhaps because he's in the business of patenting thermal protection designs for bulb manufacturers.

Shivetya 13y ago
its not the bulb that gets warm, after having one on awhile take it out of the fixture and check the base of it. I have two in tulip style fixtures where the bulbs point down, they don't last long but receipts are a wonderful thing. Eventually I think the big box store I get them from will change their return rules
- jamesaguilar 13y ago
  As long as they have a ten-year replacement guarantee, I guess it doesn't matter as long as it's not a fire hazard.
  - ScottBurson 13y ago
    Fire hazard? They're certainly not as hot as incandescent bulbs!
    - jamesaguilar 13y ago
      Sorry, I simply didn't know. I did not mean to imply they were.
- loginx 13y ago
  I've noticed the opposite pattern in my house. Ever since we bought the place, we noticed that occasionally we would semi-randomly get a very fishy smell coming out of our staircase, and couldn't find the cause. After putting my google-fu to use, I realized it was the plastic casing of a small light fixture in the staircase that was getting very hot and slowly melting around the incandescent bulb. I've replaced the bulb with an LED bulb several months ago and I've checked the base of the socket, the fixture, and the bulb after hours of use, and all three are barely warm to the touch at all. I suppose it may depend on manufacturing quality, or as the OP article mentions, airflow.

refurb 13y ago

Wow! I actually liked this article. Taught me something I don't know, made a nice factual argument without using hyperbole. A great example of the kind of article we should see more of on HN.

tytso 13y ago

There are some LED bulbs that are explicitly rated for use in enclosures with no ventilation. The other thing to pay attention to is whether the light dispersal pattern is pointed mostly straight down (i.e., for a recessed ceiling lighting fixure) or omni-directional (i.e., for a sconce or a table lamp). Reputable stores will make this clear --- and yes, it's a bit more complicated than just grabbing a random 100W incandescent bulb. For example: http://store.earthled.com/collections/led-light-bulbs-suitable-for-enclosed-fixtures-fully-enclosed-fixture-rated-led-light-bulbs http://store.earthled.com/collections/led-light-bulbs-suitab...

cjensen 13y ago
The point of the linked article is the bulb will not last very long when hot. The article never said it wouldn't work.
- adestefan 13y ago
  No bulb will last very long when hot. This isn't something new.
  - ars_technician 13y ago
    Incandescents will. They get very hot in normal operation and last the amount of time you would expect from an incandescent.
    - Filligree 13y ago
      Which is not, by any stretch of the imagination, "very long".
      - DanBC 13y ago
        Incandescents die from thermal shock, not from being hot.
        13y ago

grogenaut 13y ago

Don't Bury the Lead Dude. I've seen senate reports that take less time to get to the point about safety warnings. TL;DR: Many leds aren't meant to be in unventilated can fixtures and will either burn themselves up, reduce lifetime, or worse start fires. At least that's what I think I got out what was mainly a lot of talk about other types of bulbs.

vacri 13y ago
Given this topic, I would have gone for the alternate spelling in 'don't bury the lead'...
- grogenaut 13y ago
  don't burly the lead?
  - vacri 13y ago
    'lede'

pkulak 13y ago

I still have no idea why an led bulb is better than CFL for home lighting. From what I can tell, people just like new stuff.

dangrossman 13y ago
> I still have no idea why an led bulb is better than CFL for home lighting * They use 30-40% less power, costing you less to operate * Cheap CFLs commonly had ballasts that died in 1-3 years despite higher life expectancy claims on the packages; LEDs are backed with 10+ year warranties * CFLs burn out quickly if used in fixtures that are turned on and off frequently * LEDs don't flicker/strobe like fluorescent lighting * Virtually all LED bulbs work in dimmers, not just more expensive specialty ones * Cheap LED bulbs don't produce bluish light like cheap CFL bulbs
- mrgriscom 13y ago
  and they rise to full brightness immediately... and they're indestructible... and they're not filled with mercury...
  - vacri 13y ago
    To be honest, I like my bathroom light to wake up alongside me in the morning.
  - pilom 13y ago
    An CFL bulb has less mercury in it than a can of tuna: http://www.lamprecycle.org/public/images/docs/LD+A%20August%202009.pdf http://www.lamprecycle.org/public/images/docs/LD+A%20August%...
  - OneOneOneOne 13y ago
    Exactly. With small children in the house this is a good thing. I use them in torch style lamps to save energy and not break when tipped over. With incandescent bulbs I was also concerned with electric shock from broken bulb, cuts and burns... though I wonder if the LED bulb would be a fire hazard if it were to rest on something.

deleted 13y ago

[deleted]

jwr 13y ago

I've spent a lot of time recently working on my own LED lamp designs. Heat dissipation is indeed the biggest problem, the second being the cost and complexity of interfacing to an AC network of 230/110V. I think new kinds of fixtures will need to be designed, as well as new standards for DC distribution within the house (I am trying out 48V and 24V). Retrofitting existing infrastructure with LEDs makes no sense: we get wasteful, fragile and inefficient systems.

kalleboo 13y ago
> as well as new standards for DC distribution within the house (I am trying out 48V and 24V). This is something I've wondered about for a while. Everything in my home aside from a few kitchen appliances is now running a AC<>DC converter. At what point does it make more sense to run DC circuits in the home? Would the gauge be a problem to run enough DC power for a desktop PC, a TV, and a ton of LED lights?
- jwr 13y ago
  I think you need to strike a certain balance: for longer stretches of wire and higher wattage AC will work better. What doesn't make sense is building tiny switching power supplies into every lightbulb. I was planning to use a power supply for every group of lights — e.g. one for the ceiling, one for under-cabinet lighting, etc. That way you don't have to run long stretches of wire with DC, and yet you don't have to build lots of tiny low-efficiency converters.
  - kalleboo 13y ago
    For lighting-only, IKEA sells a mix-and-match LED system where you can connect 10 different units to a single power supply (units being various LED strips, spotlights, etc), with varying lengths of extension cords (up to 2m I believe).
Perseids 13y ago
> Retrofitting existing infrastructure with LEDs makes no sense: we get wasteful, fragile and inefficient systems. I wholeheartedly agree and would go even further and reimagine our current illumination concepts. At the moment we mostly have a few powerful point light sources. Given the longevity of LEDs we could easily design walls and furnitures with hundreds of less powerful LEDs that would produce a much more even illumination, have far less problems with head dissipation and be cheaper to produce than those high luminosity LEDs. And even more interesting, this would open the door to far more creative designs than we have now. With OLEDs you could even have glowing wallpapers: http://oled-werbedisplays.de/wp-content/uploads/2013/02/oled-wallpaper.jpg http://oled-werbedisplays.de/wp-content/uploads/2013/02/oled...

Zoomla 13y ago

They also currently take much more energy to manufacture then an incandescent bulb.

nickhalfasleep 13y ago

What a bullshit dataless fearmongering article. If your lamp and enclosure are UL rated then the on-die temperature is well within operating parameters for the 6000 hr+ lifespan. If you go with a CREE or Philips lamp then their thermal design was built for the cooking the L-Prize and Energy Star demands of them. The DOE took their and customer experiences with CFL's to heart when designing goals for Energy Star LED lamps. Source: I was a lighting engineer at a major Independent Testing Laboratory for 5 years before going to software full time.

nickhalfasleep 13y ago
In short, get only Energy Star certified lamps http://www.energystar.gov/index.cfm?c=ssl.pr_why_es_com http://www.energystar.gov/index.cfm?c=ssl.pr_why_es_com To get the Energy Star rating, the manufacturer must get an independent lab to measure their operation at 45C and measure the temperature on the die (per the LED manufacturer's specs), to validate that it will maintain it's life expectancy. http://www.energystar.gov/ia/partners/manuf_res/downloads/IntegralLampsFINAL.pdf http://www.energystar.gov/ia/partners/manuf_res/downloads/In... If you want to read all the nitty gritty details.
- mcguire 13y ago
  "the manufacturer must get an independent lab to measure their operation at 45C and measure the temperature on the die" In an environment with no airflow?
  - nickhalfasleep 13y ago
    There is convection off of the bulb, but no flow from any other source. They want to make sure they can sit and take it.
    - mcguire 13y ago
      That might be a problem, if the bulb was installed in a recessed ceiling can, right? Convection would heat the environment in the fixture.

stcredzero 13y ago

Aren't we hobbled by the legacy interfaces for light bulbs, in much the same way that SATA isn't necessarily the best interface for flash SSDs? LEDs are a different thing. It seems like lamps that use them should have thermal management built into them. The increase in surface area would make thermal management much easier.

magnawave 13y ago
Yes this is exactly the problem - less so with CFL but hugely so with LED. LEDs should appear as a part of the fixture itself - not as a screw in replacement for the legacy Edison socket. I suspect this will happen eventually when people start to see all the cool lighting options you have with LED fixtures - but its going to take a good while to get the mental shift to happen!

ubercore 13y ago

I really dislike this article. It took me a little bit to figure out why. Most of the annoyance comes from fatigue of reading this kind of thing. "Humvees are more carbon neutral than a Prius" kind of thing. Besides my personal annoyance though, this kind of unbalanced and unrigorous article is just flat out dangerous to public discourse on a pretty important issue. LED bulbs have strengths and weakness, to be sure. I didn't think the heat issue was a "secret" that "nobody will tell me". It was the first thing mentioned in nearly every single article or story I've seen about LED bulbs. I've been using LED bulbs for about 4 years now (in regular fixtures, closed fixtures, outdoor fixtures in summer and winter, closed bathroom fixtures) and have not had a single issue. As others mention, even if I did there's good warranty coverage. I'm probably more radical than most on energy issues, but I find this kind of FUD downright irresponsible. It also is part of this annoying trend of people that really enjoy trying to poke holes in new technology. Like electrocuting elephants with evil electric distribution technology.

hyperpape 13y ago
In mild support of your comment: I haven't bought any LEDs yet. I found out that they had reached practicality when I saw a display in Home Depot a few months ago (last I'd heard was years ago, that they were too expensive). Yet I still managed to hear that you can't use them in enclosures. I can't even remember where: it might have been some guys talking at the office. I'm sure that there are people out there who don't know this, but it also seems like it's approaching common knowledge.
maratd 13y ago
> I'm probably more radical than most on energy issues, but I find this kind of FUD downright irresponsible. FUD? Seems like common sense to me. If something comes with a heat sink, it's to disperse heat. If you're dispersing heat, you need airflow. I know this. You know this. But the average consumer does not. Consumers should be aware of this and this article accomplishes that. Please keep any fanatical environmentalism to a minimum. Nobody is saying LEDs are bad. I own quite a few. It is, however, important to know how to use them effectively.
- 13y ago

Spooky23 13y ago

The whole lightbulb debacle is a great reason why the government regulatory regime needs to stop meddling with the marketplace. Until 2000, buying a lightbulb was an unconscious act. You go to any store, and buy a fucking lightbulb. 80% of sales were 60w. Some applications call for different bulbs. Now, solutions for getting light out of edison sockets take up A FULL AISLE in Home Depot, with a dizzying array of choices that are difficult to evaluate. You can buy normal lightbulbs, except that now most of them are mislabeled -- a 60W bulb may actually be 50W. 100W bulbs are impossible to find and cost $5/ea. You can buy CFLs. Some are great, others make your living room look like a gas station bathroom in 1960. Most suck, and as a layman, I now have to know what color temperature is. And, oh yeah, many bulbs, which cost 5x-10x the original bulbs, burn out quickly in fixtures, or burn out quickly when in any orientation other than a standard lamp. (ie. put them in sideways, or mount them upside down) Now you have LEDs, which sometimes have better light quality, but they cost $20. And while they may last longer, you need to be an engineer to evaluate the appropriate bulb for the appropriate application. Just let me buy a bulb and pay more for electricity.

jonknee 13y ago
> Now, solutions for getting light out of edison sockets take up A FULL AISLE in Home Depot, with a dizzying array of choices that are difficult to evaluate. So that damn government meddling has resulted in too much choice in the free market?
- Spooky23 13y ago
  No, it's resulted in a bunch of subpar choices by largely eliminating the best choice from a qualitative perspective. The government decided that modifying the electricity demand curve was more important than me having light that meets my needs when the sun goes down. A free market approach would allow me to make decisions based on cost and other factors. For example, my basement and garage are lit by efficient CFL and very expensive LED lighting that was installed when the house was purchased several years ago. In my office, I find a standard incandescent bulb better than the more efficient alternatives. I value not getting a headache every evening more highly than the $8 I spend in electricity annually on those bulbs. So now I have to resort to hoarding light-bulbs. I'm an engineer passionate about efficiency, so I tweak stuff like this. My mom isn't -- she ends up suffering with awful light.

mistercow 13y ago

It seems like the obvious solution to this is to actively increase airflow. Small fans or synthetic jets could be included on the bulbs themselves, although this would be tricky to do compactly, especially for fans. Alternatively, they could be built into light fixtures designed specifically for LED bulbs, which would be less expensive overall, and would allow the cooling to be designed for the specific fixture (face up vs. face down, for example).