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
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.
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).
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.
The wires would be too big. You just can't send enough power at a low voltage. You'd need either lots of dedicated wires to each outlet, or a wire as big as a hose.
AC is nice because it's easy to convert to other voltages. With DC you'd need either the exact voltage - or a converter, and if you have a converter you might as well just go directly from AC.
Seems like Power over Ethernet would be a pretty good standard to go with. Right now it's good for 25.5 watts at 44 volts. Wikipedia says some vendors have tweaked the standard to use more lines and get it up to 51 watts. To over-simplify, the higher the voltage the less loss there is on the wire for a given amount of energy (amps).
Added bonus you get ethernet too so any devices like LED lights, cameras, etc can be programmable without wifi/zigbee/etc.
You would still need a DC/DC converter, and if you do that you might as well just go from AC.
You are thinking wall-wart type applications. I'm more along the lines of infrastructure, lights and other permanently installed devices that can be designed from the ground-up to operate at 44v.
Maybe not, but you could certainly replace recessed canisters, or other fixtures with those that have AC/DC power supplies built in, in such a way that they can have a larger surface in the ceiling/walls or even in the fixture that can then not be part of the "bulb", and subject to the same size constraints.
A universal DC standard isn't a silver bullet. Different circuits/devices and different batteries require different voltages, so there are still conversion steps to go through. Not so long ago when linear regulators (which tend to be better at producing heat than desired voltages) were typical, this would have just meant another wall wart for most devices. Even now, it still means some added cost, complexity, size, and weight.
There was that one video about a guy who built a solar-powered house off-grid which uses DC to power anything. I believe he used several wires which he could combine for different voltages. Let me look if I can find it.
Low-voltage at any meaningful distance is extremely lossy. Unless he's using big expensive wires, he's going to have a lot of voltage drop on any load beyond a small gadget. Even just pulling, say, 50 watts out of a 12-volt socket with a 20-foot run of 12 AWG behind it gives you a voltage drop of over 2% at the socket. At 120V/12AWG, the drop would be 0.22%. You'd have to use ~2AWG to match that. That's a lot of copper.
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.
It's a cheap trick of appearing honest by using impossible hyperbole. The meaning of the statement is so obviously not equal to its literal meaning that if the writer is challenged over the honesty of it he could plausibly defend it by saying, "It feels like this fact is not being communicated sufficiently to consumers who are not familiar with LED lighting." In other words, it's a way to manufacture compelling copy without needing any facts to back it up.
Sorry, I should have elaborated. It's oxymoronic when it's the title of a paper which entire purpose is to tell you what it just said no one would ever tell you.
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.
So, I actually own an LED lighting company, and I found the article quite fair. This has been bugging me for a while with the new LED bulbs, there's frankly no reason to get them to replace a CFL except for mercury, and the build quality is garbage. The heat sinking stuff is absolutely critical, and while yours may be fine, a lot of these bulbs (and more every year that new players get into making them) are simply not amenable to being used as direct replacements without some extremely clever design that's not being done.
Not to mention that the incremental efficiency gain is negligible. Incandescent to CFL is a huge efficiency gain, so you can actually pay back the increased cost in electricity usage in a short while. A 60W equivalent CFL might consume ~13W. A similar LED bulb will be around ~9W. That extra 4W is such a marginal improvement that it would take decades to make it back in energy cost. So the only selling point is lifetime, and I've seen no indication that there is a big difference between the two -- both have similar types of failures, usually control electronics or power supply passives due to poor quality manufacturing.
In my observation, it is not enough for most people. They need an economic reason as well. Besides, the amount of mercury in a modern CFL is not all that bad as long as you don't try to vacuum it up and.
Disclaimer: I'm sort of a chemist, so let's just say I've been around far, far worse than a few milligrams of mercury. I do have a healthy respect for safety hazards, and am very cautious, but I don't have a strong immediate inclination to avoid small amount of mercury (or DMF, or THF, or paint thinner, or...) outright as too risky.
Even if you'd have spilled all of the mercury on the carpet (and most of it will possibly have stuck on the inside of the bulb and been disposed of with the shards), it will have evaporated (and hence, left the room in gaseous phase) a long time 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.
Sure, I went off the handle a bit, but the thing that really set me off here was "what nobody will tell you." It's linkbait-y FUD. Every communication around LED bulbs I've seen has mentioned the heat issue.
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.
Fwiw... The elephant thing was a planned execution of an aggressive elephant. The video being shown as far and wide as possible(and likely the reason he got involved in the first place) was a business decision by Edison because he had a lot of money invested in DC distribution.
The entire first part of your response is pointless. You are essentially admitting that you are annoyed by articles that don't agree with your preconceived notions. "it bothers me because it doesn't fit my version of black and white" is not an argument and does not belong in this discourse.
I was just using that to lead into the thing I really wanted to say. I admit my dislike is my problem. I thought that I followed it up with reasoned and thoughtful discourse. What part of my statement do you disagree with?
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.
Those Cree/Home Depot bulbs were brand new this spring (2013). If you've got LED bulbs that have been going for two years, they're probably something else.
The oldest ones are whatever store brand Home Depot dropped under $15 first. Ecosmart maybe? That's when I started replacing CFLs. I switched to only buying Cree when those dropped under $10 too.
The Cree bulbs - at least the ones in Home Depot in Canada - actually do have a warning about using in enclosed fixtures. It says (to my recollection) "Do not use in enclosed fixtures with other types of bulbs". So my take on this is that they are supposed to be OK providing you don't mix the Cree LEDs with CFLs or incandescents in the same fixture.
I am trying them out in some enclosed fixtures, too early to tell how that will work out.
I've uploaded a photo of both sides of the Cree product packaging here in the US. It's the same for 40W and 60W bulbs. There's no notice about not using it in any type of fixture. The only thing it says not to do is expose the bulb directly to weather.
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
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.
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:
They die because over time the filament sinters causing grain growth and necking at the edges. The individual grains shift until due to the 1D constraint they each have grain boundaries with each other that stretch from the radial edges of the cylinder across. Once the grain boundary looks like that, you see increased surface diffusion at the grain boundary near the surface that forms a pit which weakens the filament.
Perhaps you could argue that it requires cycling because the cooling causes increased axial stress and gradually pulls the filament apart, but it is most certainly more complicated than just thermal shock. I believe that so long as you're not shattering glass, it's more about how long it's been hot so far and how many times it's been completely cooled.
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.
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.
If your lamp and enclosure are UL rated then the on-die temperature is well within operating parameters for the 6000 hr+ lifespan.
6,000 hours? Where does that come from?
The L-Prize bulb claims 30K hours; most of the LED lights I've seen for sale claim lifespans in the 25K to 50K hour range. Are you saying that 6K is all we can actually expect?
To actually get just 6K hours from a bulb that cost you US$30 or more (the L-Prize bulb is $70!) would be very disappointing.
Since the bulbs last so long, and it would be prohibitive to wait until a death rate of 50%, they use 6000 hours as the laboratory test time which has good correlation with information known so far from LED manufacturers. By that age they tend to be in a main sequence of life.
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.
> 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?
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.
"You can buy CFLs. Some are great, others make your living room look like a gas station bathroom in 1960."
Please, please don't. We all have a duty, with our wallets, to make CFL die. It is garbage, stopgap technology that should have been strangled in the crib. Oh and also it's toxic waste.
Buy LEDs. Buy incandescents. Buy xmas tree lights. Buy anything but CFLs.
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.
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.
Ever wonder why a "Halogen" light bulb has that name? Well, what happens if you try to create a very bright incandescent lamp is that when pumping so much electricity through a filament and heating it up to incredible temperatures you'll actually start to evaporate the filament. This is a common failure mode for incandescent bulbs, a part of the filament will get thinner due to evaporation and then the reduced thickness will increase resistance in that section, accelerating evaporation and eventually causing a break. But if you put a small amount of Bromine or Iodine gas (halogens) inside of the bulb, and a small amount of Oxygen, then the evaporated metal will form a Tungsten OxyHalide gas which will then redeposit Tungsten metal through an electro-chemical reaction back onto the filament, increasing the filament's longevity even at very high power levels.
> A regular light bulb converts about 2% of its energy input into light, and 98% into heat.
This isn't relevant to your argument, but that actually isn't true, that figure is about 6~8 percent.
* The "luminous efficiency" as commonly reported is just the lumen/W luminous efficacy divided by the peak value of 683lm/W. The value of 683lm/W is the peak of human eye sensitivity curve and occurs at 555nm. The only light source that can achieve 100% "efficiency" by that measure is a 100%-efficient radiator that emits monochromatic 555nm (bright green) light, the best a perfect white light source can do is about 37%. (see [1])
* That "perfect white light source" would be a 100%-efficient radiator emulating the Sun spectrum bandlimited to visible light (zero infrared, uv and no other losses).
* It's possible to make a light source that appears white to human eye and is more efficient than that by emitting mostly at wavelengths the human eye is more sensitive to, and emitting less at wavelengths it's less sensitive to. That's part of the reason why manufacturers often offer CFLs with high efficiency but poor color rendering and lower efficiency but higher color rendering. (And don't get me started on the color rendering index.)
* That definition of "efficiency" is obviously not what most people think it is when they hear that word (useful work / total work spent), some prefer to call it "luminous coefficient". But it's not all lies, it was defined that way because it's easy to compute and understand and because this is the value of interest if e.g. you're making a LCD backlight or if you're designing an interior lighting setup.
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.
> In terms of energy efficiency, CFLs are halfway between incandescent bulbs and LEDs.
That isn't true. LEDs are equivalent to CFLs in energy efficiency. The only LEDs that are more efficient are either lying to you (they claim the light is more directed so it "counts" as more, and they uprate the bulb), or they have worse color accuracy so you are not comparing equivalent bulbs.
> 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.
No. The heat source is not larger - it's in a different location, it's in the bulb part and it emits infrared light and is sent into the room. With LEDs the heat is made in the base and stays there.
> With all those coils and folds, CFLs have a larger surface area than most other types of lamps, so they cool easily.
That doesn't explain why an incandescent that makes 6 times as much heat can manage, but an LED can't. It's not the cooling of the bulb, it's the type of heat - incandescents and CFLs make their heat in the form of infrared light that is sent into the room.
> The only LEDs that are more efficient are either lying to you (they claim the light is more directed so it "counts" as more, and they uprate the bulb), or they have worse color accuracy so you are not comparing equivalent bulbs.
Let's exclude lying vendors.
Worse color accuracy is annoying for those who care, but as far as total energy output is concerned, it shouldn't matter. A watt is a watt no matter what frequency it is radiated at.
> The heat source is not larger - it's in a different location, it's in the bulb part
Sure. And the bulb of a typical CFL is hundreds of times larger than the die of an LED.
> That doesn't explain why an incandescent that makes 6 times as much heat can manage, but an LED can't.
As I mentioned in the great-great-grandparent comment, glass tubes (CFLs) and tungsten wires (incandescent lamps) are much less sensitive to heat than tiny pieces of delicate electronics are. 85'C is child's play to glass and tungsten but deathly to silicon.
> incandescents and CFLs make their heat in the form of infrared light that is sent into the room.
The "sent into the room" part is definitely correct. LEDs overheat more easily because the heat is generated and trapped in the base. But even if you dangled a bare LED in mid-air, I doubt you could make it as cool as a CFL because the heat source is concentrated in such a small area. I'd also be surprised if those LEDs didn't generate a lot of infrared ratiation.
> but as far as total energy output is concerned, it shouldn't matter. A watt is a watt no matter what frequency it is radiated at.
Ah, but if you are willing to have poor color accuracy then CFLs should be allowed that as well, and if you do that then their energy efficiency is better than an LED.
> glass tubes (CFLs) and tungsten wires (incandescent lamps) are much less sensitive to heat than tiny pieces of delicate electronics are
CFLs have switching power supplies in the base that don't like heat either. It's not just a glass tube. But I'm willing to accept that they can handle heat better than an LED emitter. (And I'm pretty sure it's just the emitter with the problem - it's certainly possible to make "delicate electronics" that can handle heat.)
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.
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)
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.
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.
> 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.
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.
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.
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.
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.
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."
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?
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.
Thermistors will help, yes, but the manufacturers need to design better enclosures for LED lightbulbs. They need fair air circulation for that heat sink to work well. And in recessed lighting it's the worst.
It's a design issue of the bulb, sure, but especially the fixture. LEDs aren't friendly to high heat like incandescents are, and most light fixtures have been designed with complete disregard to the heat of the fixture—so long as it won't start a fire.
The CFL has a huge volume and a huge radiating area for the heat, and that area is well-connected thermally with the environment. Plus, it can operate at higher temperatures anyway.
The LED active element is a tiny chip of semiconductor material. All that heat is dumped in a tiny volume, and you can only put a heat sink on its back. Plus, the heat sink is close to the fixture and therefore necessarily hampered in its function.
It's not an easy problem to solve. If we think pie-in-the-sky solutions, perhaps a re-design of the connectors and fixtures might help - if you made a connector that was designed to take heat away from the bulb, that would help a lot; the whole fixture would become the heat sink.
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.
This isn't a car, which you expect to require some expertise. It's not a furnace that will be primarily handled by an HVAC specialist. It's a light bulb. Consumers have a reasonable expectation that devices like this Just Work. If the device fails to meet its promised service-level without a dozen asterisks in its usage? It's not meeting its intended purpose and it's defective.
Consumers should not have to meticulously research every small purchase. Simple, small purchases of replacement parts should not require reading a 10-page instruction manual of 6-point font, especially since you didn't get this manual until after you got the damned thing home.
By allowing manufacturers to sell these defective devices, we don't just hurt consumers, we hurt the environment with unnecessary waste of electronics, and we hurt the real, quality manufacturers who want to sell good stuff but can't because there's no way to tell consumers "all the other crap on the shelf will break in under two years and we won't" so they end up getting crushed by people who cut corners.
"Educating the consumer" is the onus of the manufacturers. It doesn't mean 10-page instruction manuals with 6-point font or hours of meticulous research [edit: this is a horrible way to educate consumers]. In this case it probably means packaging and labeling which plainly states "not for use in recessed fixtures" in a way which most anyone would understand. This could be a sticker which says just that, it could be iconography, it could be an obnoxious DVD on loop in the lighting aisle at Home Depot, or it could be all of those things.
Yes, it's a light bulb (a light bulb!) but that doesn't mean manufacturers shouldn't attempt to get consumers to use it properly.
If your product requires that you "educate consumers" away from using it in a way that they can perfectly reasonably expect it to work? Your product is defective. A big warning label on the front of the box is the only reasonable accommodation for this, but in the real world this kind of defect ends up in the fine print.
If you want to make a special light-bulb that is only compatible with a narrowly defined set of environments, then make your own socket that is only compatible with your bulb and then sell fixtures that provide the needed environment.
If you want to use a standard socket, then you have to take the bad with the good and also deal with the kind of environments you'd find. This is the same bullcrap with devices that completely fail to charge on 0.5Watt USB power-supplies. If you can't charge off a standard USB connection, then you shouldn't use a USB port, because USB defines 0.5Watts and your device isn't USB-compatible. Legally required to support USB? Then stop pussy-footing around and actually support it instead of exclusively supporting a 1 or 2 watt perversion of the standard.
The need to educate a customer usually surfaces when someone was unable to produce a proper product. Sure, you need to warn users when your product can't be used under some circumstances, but if possible, you should aim at fulfilling the users' expectations instead.
Touché. The comment was mostly directed at the hyperbole of "10 page manuals" and such.
I totally agree with what you're saying, though.
The issue at hand is that consumers want something that is impossible for manufacturers to give to them. That is, a 100% efficient lighting solution which shines light exactly when they want it, exactly how they want it, and lasts forever. Consumers have gotten used to a market where there has been almost no innovation for over a hundred years (in the driver side, fixtures are a different story). Now that there's some diversity in the market, consumers are unhappy because it's not matching expectations. The only way that will change is if manufacturers properly set expectations.
I'm not so sure we won't see the desired solution, and soon. Pretty good illumination over a reasonable field would do the job. LED bulbs may get there sooner than you think, unless their reputation is irredeemably tarnished by the defective (read: not meeting minimum expectation) products being overmarketed today.
Now that dimmable 60-watt equivalent LED bulbs have dropped into the sub-sawbuck range, I was examining the packaging at my local Home Despot store. I remarked to the salesman who asked to help me how the iconography on the front of the package suggests that the bulb is suitable for use in your standard ceiling-mounted light fixture--which is usually enclosed--but the fine print on the back explicitly states that the bulb is not intended for use in enclosed fixtures. He agreed that the ceiling fixture icon was misleading, and that the fine print is what I must consider most authoritative.
He did note that the Cree brand bulbs are actually rated for use in enclosed fixtures, but alas, they're also more expensive at the moment than these other guys.
Lighting is a horribly underappreciated aspect of modern life. "A light bulb is a lightbulb" sounds rather like "a car is a car." Placement of lighting, color temperature, thermal characteristics of a particular light, etc. should all be considered carefully. It's not such a stretch to expect consumers not to put certain bulbs in certain places. It is a stretch to expect one type of bulb to work in every place, and have the desired aesthetic.
> Lighting is a horribly underappreciated aspect of modern life.
Everything is a horribly underappreciated aspect of modern life. You'll hear the same sentence with one word changed uttered by audiophiles, vegans, electricians, foodies, urbanists, doctors, social justice advocates, janitors, seniors, juniors, teachers, genealogists, biologists, ecologists, chemists, astrophysicists, philosophers, grammarians, body-builders, trainspotters, mechanics, open-source software fans, designers, photographers, documentarians, readers, writers, gun-nuts, gun-haters, pastors, prudes, perverts and relationship councillors.
We, collectively, no longer give a fuck. We are out of fucks to give. We are way past peak-fucks and into a severe fucks crisis. We have zero fucks.
I just want to buy something and have it work. If the colour temperature is wrong and the aesthetics are therefore sub-optimal? Well that reflects the effort I put in. If it burns out in a week? It's defective, full-stop.
> Simple, small purchases of replacement parts should not require reading a 10-page instruction manual of 6-point font, especially since you didn't get this manual until after you got the damned thing home.
One wonders what the owners of gaslights thought when they bought their first simple "Just Works" light bulb.
And of course many of us were there for Grandpa Versus the Microwave Oven.
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.
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.
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
> (except when dimmed -- nothing can match the fireplace-like glow).
I can't talk specifics (under NDA from a former employer), but this is a problem for which solutions exist. I don't know that manufacturers think there's much of a market there, however.
> Which has made me wonder if this switch to LED is way more complex than just those two measurements :P
It is. There are a bajillion things going on. One which you've already noticed is how dimming impacts color temperature. CRI is also a huge issue. Then there's the optics - LEDs are very directional, so they require pretty advanced lenses in order to achieve a desired lighting pattern [1]. Optics impact all kinds of things, including color temperature, and since the development cost is high you can expect cheap brands to skimp there. If you're comparing them by looking directly at the bulb, internal glare/reflection is hard to match as well.
I'd still caution against using the A19s in a recessed fixture. It's not a safety issue (that I'm aware of), but you definitely won't get the rated life out of the bulb.
Out of curiosity, did you try an LED BR30? I think you might find one from a quality manufacturer to be a bit better than the A19.
1: $20 says the lighting pattern on the Sylvania LED is smoother/more regular than the Sylvania halogen, but I'm biased since I know the guy who designed the lens.
http://www.switchlightingco.com produces excellent (though expensive) LED lights which are, I'd say, 95% of what I could want out of a halogen replacement.
If it's been oked by multiple electricians, it's probably OK. As your article states, properly installed knob and tube is at least as safe as modern wiring.
The major problem is that since knob and tube lost favor and today, demand for electricity within the home has grown considerably, and a lot of knob and tube systems were expanded improperly; this can happen with modern wiring as well. Also, the insulation issue.
Knob & tube left in place is generally safe. If you want to do anything at all with the electrical system, however, you'll need to upgrade the whole system.
The same thing happens to incandescent bulbs. If you put a regular light bulb in an enclosed housing it's going to burn out fast due to the excess heat, too. This really is a baseless attack.
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.
Incorrect. That article is comparing the estimated exposure from a broken CFL with the exposure from eating Albacore[1] tuna. The actual mercury content in the CFL is obviously much greater.
[1] And not all canned tuna is Albacore. The stuff sold as "light" tuna is typically lower mercury content (don't have a source handy at the moment.)
I've broken one bulb in a decade. But by being an early adopter and using them for more than a decade I've prevented hundreds of times as much mercury from entering the atmosphere.
People used to play with mercury as a toy, even drink it just to watch it pass through their digestive system. It's a very good thing people don't do that stuff anymore, but there are probably far worse things than mercury hiding in household items and chemicals.
I bought a huge box of big CFLs when a nearby store went out of business, for something like less than $1 a pop. Not quite a lifetime supply, but I am definitely not going to be an early LED adopter.
Generally speaking, you are looking at this incorrectly, and if enough people share your views, it impedes progress. By voting with your wallet on newer technologies you help to fund further advances. Granted, it takes millions of people to make a difference but I would hope that the HN reader would be leading the way.
Unfortunately there are also plenty of bar owners who are voting for carbon filament incandescents with their wallets. They are even less efficient than tungsten, they last less and the glass gets black from soot, but they look oh so hipster.
I'm not saying that everyone has to lead the way, but that if enough people do then progress continues at a faster pace. 4k monitors will be commonplace in 3-8 years, for instance. The rate of early adoption will determine how fast companies invest in them.
I wasn't being sarcastic, I for one think that incandescents should be banned (and I think they have been in several countries). The reason that has to happen sooner rather than later is not progress for progress' sake IMHO, but the environmental damage inefficient obsolete tech causes.
Why should they be banned? Why should people not be allowed to waste electricity and glass? We don't have shortages of either, and by melling's argument doesn't dumping money into electrical generation encourage advances there, the same way that dumping money into LED leads to LED advances?
Basically: If you want people to use less power, then increase the price or ration it. Don't ban an unrelated technology. If you want people to use less glass, haha are you kidding me, glass is made of dirt and easy to recycle.
Is there any harm caused by incandescent bulbs specifically that I have somehow missed?
By your logic, we should have not banned CFCs in household goods but instead made them more expensive.
The reason for why we want to have energy efficiencies is simply because we only have to produce so much more electricity to power everything else. We have not reached a point where nuclear, solar, or wind is cheaper by the MW than coal and as a result we'll continue to build those for the foreseeable future. Banning inefficient and obsolete light bulbs will prevent us from needing to burn more coal and other harmful fuels.
If we didn't have this problem with electricity generation then banning something may become less desirable.
CFC deplete a limited resource. Electricity doesn't inherently do that. If you're in charge of the laws, you can make non-polluting energy cheapest and do far more good than coming at the issue from the side by legislating light bulbs.
Or you could be really direct and make a law against powering incandescent bulbs on coal power, letting everyone choose if they want to buy some renewable/nuclear energy for their wasteful bulbs.
No, but for the moment it does actually do that. And you can change what sort of light bulbs people use faster than you can change your large-scale power generation technology.
(I do agree that making environmentally-better energy cheaper is likely a more powerful way of reducing the environmental cost of electricity use than telling everyone to stop using incandescent bulbs. But "X is better than Y" is a reason for doing X, not necessarily a reason for not doing Y.)
> a law against powering incandescent bulbs on coal power
Enforcing that one would be an interesting challenge. A law that says "no selling incandescent bulbs" is rather easier to enforce.
By your logic, we should have not banned CFCs in household goods but instead made them more expensive.
Lots of people would agree with that or the point in general that financial penalties work better. Legislation should mandate results, not dictate methods.
Are there any studies on how effective each method is? It seems fairly complex, depending on how good the methods being dictated are, how price-sensitive consumers are (and how well-informed about what costs/saves money), costs of switching, in some cases economies of scale, etc.
The conventional wisdom here (Denmark) has been that a mixture of the two achieves best results: a high tax on energy to provide an across-the-board untargeted price incentive, plus specific targeted regulations aiming at cutting out the largest sources of inefficiency and encouraging economies of scale in more efficient technologies. So for example district heating is now mandatory if you're in an area where it's available (no furnaces in new construction), and this seems to have been quite effective in increasing its adoption, which in turn makes it easier to build efficient district-heating networks and cogenerating power plants, since there is a dense customer base.
I don't know specifically. I do know that all of the "alternate fuel" tax credits are a giant scam. How does spraying kerosene on coal make it clean? No clue, but the government will pay you to do it if you say it's alternative.
I suppose anything is possible. The point is it would be better for the government to mandate results (lower emissions, which can be measured) than methods (spray kerosene on coal and hope it does something useful).
In what way? I used to think that when I first tried them ~6 years ago, and switched back to incandescent. But I tried again ~2 years ago, and now I can't tell the difference between a name-brand CFL and an incandescent bulb. Visually appears to have the same color temperature, no flicker, instant-on brightness. I'm sure there are still low-quality off-brand CFLs that take time to get to full brightness, but it's been years since that was true of the good ones.
The only cases where I don't see a CFL replacement yet are decorative clear lamps where the filament being visible is part of the aesthetic.
* To me, they just look dark. A 60W-equiv rated CFL is never as bright as a 60W incandescent, more like 40W when new.
* There are notable gaps in the spectrum causing color distortions. CFL light mostly features a greenish or violet shade and looks "hollow". Tungsten and halogen are way better, even after 20 years of CFL development.
* Most, even the more expensive ones are not really instant-on. They reach their max brightness after some time
* As I regularly switch off lights in rooms that are empty, they tend to fail rather fast.
That last one is the killer for me. CFLs don't get anything like their rated lifespan unless you leave them on all the time. In my experience they burn out faster than incandescents.
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.
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.
> 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...
> 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?
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.
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).
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.
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.
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.
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).
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.
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!
> 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
> My experience doesn't jive with your unwarranted jabs.
And my experience doesn't jive with your list. And they were not jabs [seems like you edited out that part of your response], just replies to each point. Nor did I accuse you of making it up - read again what I said. Just that simply because you have that experience doesn't mean it's like that for everyone.
I have lots of CFLs in my house and none flicker, and they all seem white to me.
I bought a cheap LED for outdoor lighting, and it's noticeably blue. Which is fine for its intended purpose, but my experience has been the opposite of yours.
You're acting like your experience is the ultimate truth and anyone has who has a different experience is attacking you or has some strange problem.
I also find LEDs to have a speckle pattern sort of like a laser. I find them very unpleasant and harsh.
Hm. I went to the store and compared CFLs and LEDs for the same lumen rating. Their electrical power was about the same.
Flicker - I actually have an Ikea LED lamp that has two active elements inside (2 LEDs). The supply is a simple 12 V AC transformer. I suspect the two elements are connected in a push-pull (anti-parallel) circuit, because they've started to flicker recently - if mounted push-pull and not equal in terms of brightness, that would explain it.
I thought CFLs produce more of a weird green hue - at least that's how both my eye and my cameras see it. At any rate, the main emission line of Hg is smack down the middle of the green part of the spectrum.
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.
Very high failure rate (including one case where my wife called the fire department because something was burning in the house and she couldn't identify it), warm up time, and has to be treated like HAZMAT after it has completed it's six months of duty—indeed, what's not to love about CFLs, and why should I bother checking out an alternative?
Yes, I purchased my LED bulbs in anger. We'll see if I've been had.
The UL has now required end of life circuits in all CFLs so this won't happen again in new CFLs. (And new is relative - this regulation came about a few years ago.)
At least in theory, they're more power-efficient and last longer (though, as this article suggests, that may or may not be true). Things that are pretty much universally true, though: they turn on faster, have no warm-up time like most CFLs, are more often dimmable, and typically have better spectral distribution (though not as good as incandescents), which tends to make them less likely to impart the sickly cast that things lit with CFLs take on.
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.
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.