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Main Area and Open Discussion => Living Room => Topic started by: mouser on May 16, 2014, 01:30 PM
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So I have begun experimenting with LED light bulbs to replace my incandescents, and I thought we could use a thread to share thoughts.
Motivations:
First, let me say something about my motivations. A big appeal of LED light bulbs is their lifespan and low cost of usage. Those are not primary motivations for me -- mostly because I think with technology changing, a 20+ lifespan in theory is unlikely to be a reality -- new models will be out in 5 years that will demand upgrading.
However, I am motivated by the decrease in heat output -- in the summer my incandescents can generate a large amount of heat and i'm very keen to reduce that.
Additionally, i would like the ability to run brighter bulbs in my existing light fixtures that are currently limited to 60w.
Concerns and Issues:
There are several concerns and issues with using LED bulbs in some light fixtures:
1. Large size of bulbs. You can get common LED bulbs equivelent to 75w in standard A19 size; brighter than that they get bigger (A21) and may not fit in fixtures.
2. Weight of bulbs. These LED bulbs can get heavy -- I have one light fixture where I will have to jerry rig some supports for it.
3. Spotlight effect. The LED bulbs are more directional -- which can be especially troublesome for fixtures where the bulb is pointing up.
4. Color temperature. There are two main temperatures you see (2700k soft yellow, 5000k daylight blue); The blue LEDS seem like they are closer to flourescent than any incandescent.
5. Candelabra sizes. I have a couple of chandelier type light fixtures that use candelabra bulbs; there are some candelabra LEDS but it's unclear if they are bright enough.
6. Dimming ability, noise, flickering -- all have been mentioned in various places as potential problem areas for LEDs.
Observations and Recommendations:
I will be posting some initial observations soon -- I hope some of you other early adopters will too -- what have your experiences with LED bulbs been?
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Observations and Recommendations:
I installed some CREE 100w (http://www.amazon.com/Cree-18-Watt-White-Lumens-Omnidirectional/dp/B00JJ2KSL6/) LED bulbs (A21 size, somewhat bigger than normal) in two ceiling fan lights (4 bulbs each).
I tried soft white (2700k) and bright white (5000k); the bright white was much too blue.
The soft white was an excellent replacement for incandescents -- very bright, look just like incandescents.
Size was not a problem with one set of my ceiling fan light shades but another set is too narrow and the bulbs don't fit. Phillips makes a more tubular 100W (http://www.amazon.com/Philips-432195-100-Watt-Household-Dimmable/dp/B00G4V4VE0/) LED that might.
Dimming was ok but cannot dim to very low light. Shouldn't be a problem in most cases but if you like to be coy in the bedroom it could be an issue.
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Observations and Recommendations:
I did find one very expensive brand of LED bulb (http://www.amazon.com/gp/product/B00EJ3TD7K) that is: 100W bright, suitable for installation in an enclosed fixture, and standard A19 size.
That's a very tricky combination, and you pay for it -- but i do have one kitchen fixture where those features are important.
[though for that price, perhaps the smarter thing to do is replace the light fixture]
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However, I am motivated by the decrease in heat output -- in the summer my incandescents can generate a large amount of heat and i'm very keen to reduce that.
Additionally, i would like the ability to run brighter bulbs in my existing light fixtures that are currently limited to 60w.
-mouser
Those are two considerations I can get behind. :Thmbsup: Especially the heat reduction part since our AC operation costs did a financial number on us last summer. So anything to reduce BTUs is welcome.
I think if LED does become the dominant home lighting technology we'll see fixtures designed to use them with a far less expensive and kludgey form factor than squeezing them into an Edison style bulb.
When it comes to dimming, I think there will always be a loss of smoothness and subtlety since very few LEDs have variable brightness capabilities. Most dimming will probably be done by switching off elements to reduce overall brightness which is more like a 3-way bulb works with it's fixed brightness levels. Dimmers seem to have largely gone out of vogue anyway.
So yes...please keep us posted on what you discover. Right now I have two LED lamps - both with 60W light levels. I can't say I care for either although the rock solid absolutely flicker-free illumination is nice. And they don't seem to be bothered by the crappy fluctuating voltage levels our local utility company furnishes. Unlike our standard lights which have a tendency to need replacement about every three months because of it.
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Been using CF and LED bulbs for ~two (2) years. Garage light is a CF equivalent to a 200W incandescent, but uses between 1/3-1/2 the power. Several desk lamps with multiple small LEDs, usually ~thirty-six (36) have been working just fine to illuminate various keyboards and desktops. Not super bright, but adequate. Have a couple of torchiere floor lamps with variable controls for light levels. Cannot get super dim, but dim enough, I suppose. Significant power bill reductions, although I cannot quote values, as this has been happening over time. Now looking for 100W ceiling fan replacement lights with variable capability. Also looking for 40W equivalent bulbs for a spider light with five (5) elements and variable lighting, but I suspect that may take a while. Biggest gripe I have is converting watts to lumens :-\ ;D.
Considering that I'm pretty much planning on dying here, the costs are not significant, since I'll prolly never have to replace a bulb - except for experimental purposes, of course. Only other LED I need to find is a weather-proof variant for the front porch. Not difficult to find, but too many choices, so the choices can get confusing pretty quickly.
I wish now that I had kept better track of power and billing as the project grew, but that didn't seem significant at the time :-\, as that was not a major purpose - I just got tired of replacing incandescents :P.
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I've only one led bulb at home, but have seen a few elsewhere, and I notice that they never seem to be quite as bright as the equivalent brightness in other bulbs. In one friend's we even reinstated the old bulb to compare - I think it was 60W, and the equivalent-to-60W led was noticeably weaker.
Warm white is definitely a much nicer light too.
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A few years ago I swapped all my bulbs (> 100) to CF and found that they came nowhere near to the lifespan indicated, so I'm a bit skeptical about the promised life of LEDs.
That said, recently I bought 8 60w-equivalent LED bulbs that look like a regular incandescent bulb that's been run over by a steamroller. They're very light in weight, dimmable, and work extremely well as fan bulbs (nothing to be affected by vibration). They also give a good level of light output and I find them more than acceptable in floor lamps. This time round, I'll wait a bit longer before going the whole hog and replacing everything but, so far, I'm very pleased. I'd like, indeed expect, to see the price come down from the $12 each that's being asked right now.
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:Thmbsup:
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Haven't encountered those. Looks intriguing.
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There are a few people on youtube doing really good in-depth reviews and comparisons of LED bulbs -- you'll find some reviews of those flat types.
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I have replaced most of the light bulbs in my house with LEDs. I had been using CFLs whenever possible, but have now gotten rid of nearly all of them because I MUCH prefer the light quality of LEDs.
LED Prices have come down dramatically in the past year, helped in my area (Massachusetts) by subsidies and rebates from the electric companies: For example, the Philips flat 60W equivalent bulbs Cranioscopical paid $12 for sell for $4.99 at my local Home Depot, as do the Cree 60W bulbs. Philips A21 100W equivalent bulbs are selling there for $14.99.
3000K is the best color temperature for most LED lighting, IMHO, but it is hard to find in most sizes, 5000K is awful, except for a few situations like workbench lighting. 2700K is the standard for "warm white" incandescents and is fine for most indoor lighting and good for reading. Most current LED bulbs have a color rendering index (CRI) in the mid 80's, but I have recently found some Feit PAR-20 LED bulbs with a CRI of 93, and the difference in quality is dramatic when they are used to replace LED or halogen bulbs that produce the same nominal light as measured in lumens. I expect to seem more high CRI bulbs becoming available.
In general, I have found Feit bulbs to be the most reliable and to have the best dimming performance, but I have only seen them in a few sizes, and none above a 75W equivalent. The Philips A21 75W and 100W equivalents give good light at full setting, but tend to shut themselves down when dimmed. The 60W flat Philips are very good and I hope that design will find its way into brighter bulbs. I have generally found Cree bulbs to be inconsistent in light output and very poorly constructed.
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Replaced all the MR16/GU10 50W Halogens with LEDs, (3-4W), almost all others are CFL. I don't think I've had to replace a CFL in the last 5-8 years, (they're all used in ventilated fittings that stay on for an hour or two at the least).
I only use LEDs or CFLs with a colour temperature that approximates daylight, (~5000K), as I find the yellowish/reddish hue of warm white annoying, (if I buy a "white" light, I want white dammit!!).
Apart from a driver failing in one of the LED GU10s, (which I replaced), they've been working for the last 4 years or so without problem. All of the LEDs came from a generic Chinese goods online store, (cheaper than local prices), as either assembled or separate LED/driver/bodies.
I also installed a couple of 10W LED floodlights before leaving the country at the start of April, don't know if they're still working.
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The CFLs, which most of my house uses, last about 6 months to maybe a year (under moderate use) where I am. I don't see anything like the five or seven year lifespans claimed on the packages. Could be our local utility is to blame because they provide rather dirty power and deliver highly fluctuating voltage levels during AC season.
I still worry about the long-term mercury problem however. CFL bulbs just get tossed rather than recycled. It might not be a problem so far. But ten years from now, when billions upon billions of these things are sitting in landfills...
There's been some lame arguments that the reduction in power consumption from CFL bulbs results in less overall mercury being released into the environment in areas where coal-fired generators are the norm - because less coal (which also contains mercury) gets burned. But that sounds more like an industry thrashing around to find something - anything - to throw up against the fact that no level of mercury exposure is ever good for us.
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I still worry about the long-term mercury problem however. CFL bulbs just get tossed rather than recycled. It might not be a problem so far. But ten years from now, when billions upon billions of these things are sitting in landfills...
-40hz
They're also very poisonous if they break:
http://www2.epa.gov/cfl/cleaning-broken-cfl
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I replaced 13 GU10 Incandescent lamps (a mix of 25 / 50 Watts) in my kitchen with warm white LED spots. Each spot contained 3x1W LED's. The resulting light output was a bit less but still quite satisfactory.
Unfortunately the LED spots have a very limited life. Basically these are Chinese rubbish, the design and manufacturing are really poor. I've had two sets now and in the first set the LED's overheat and eventually one fails causing the drive circuit to destruct. In the second set the LED overheats and fails but the drive circuit survives so I've taken to unsoldering the working LEDs in one broken lamp to replace the failed one in another. It brings them back to life for a few months at least.
The root cause is that they are over-driving the LEDs to achieve light output and this radically shortens the LED life. Typical specmanship over reliability commonly found in cheap Chinese cr*p.
The replacements I'm buying now are a 'known' brand and appear much better but time will tell. Sadly any money or environmental savings have been lost many times over due to the greedy supply chain. So I recommend to spend a little more and avoid 'bargain' prices based upon imports.
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Yeah, i figure the boasted lifetime of these LEDs (20+ years) is totally unhelpful -- even if they did last that long, it's inconceivable to me that after 10 years there won't be better technology you will want to replace them with, so calculating the long-term return on investment is a bit tricky.
However, psychologically speaking I do think there is something to be said for paying up front for super-efficient bulbs, in terms of eliminating daily concerns about electricity costs. That is, i feel better absorbing the psychological pain of spending a large amount to purchase the bulbs up front, and then being able to live my lift not worrying about leaving the lights on all day -- vs. always worrying that i'm wracking up huge energy bills if i forget to turn the lights off. There is something comforting about removing the voice in the back of your head nagging you to turn off the lights to save electricity :)
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Since we have some lightbulb experts here, perhaps this is a good opportunity for me to ask a couple of questions that i should have asked before i started my journey to LEDs.
I have (ceiling) light fixtures that state very clearly "MAX 60W [incandescent] BULB". So one of the motivations for me moving to LEDs is the ability to run brighter LED bulbs that give off lumens equivalent to a 100w incandescent.
But to be honest, I don't really know what that limit on the fixture is all about. I have had a circuit fuse throw once or twice that i attributed to overloading a light fixture with over-wattage bubls.
So I guess my question is -- what exactly are those max wattage limits on the fixtures all about? What is the danger of putting higher wattage bulbs in there? Am I right to assume that I can put BRIGHTER LEDs in there as long as the electricity drain is low? Am I right to assume that the LED bulbs will not generate dangerous heat levels?
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...However, I am motivated by the decrease in heat output -- in the summer my incandescents can generate a large amount of heat and i'm very keen to reduce that.
-mouser
I have installed three Kobi (made in China) LED 75W equiv., 5000K, in my room. One in a floor lamp, one in a table lamp and one in a reading/desk lamp. I have been very satisfied so far. I like the bright light - all three are essentially positioned for indirect lighting - but the desk lamp I have used for reading, and it's great.
I have noticed, however, that while the bulb itself stays quite cool (body temp?), the radiating fins at the base become quite hot. I am not able to touch them for longer than about .5 sec. at a time. Perhaps this is because of the "made in China" stigma deprecated above, but they have been working very well for several months with no problems. If what I have experienced is common, you really haven't done a whole lot to reduce total heat output. I'd like to know if others have detected this high heat of the radiating fins between the base and the bulb itself.
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The heat fins do get very hot.. Though that doesn't definitively tell us about heat comparisons.
My limited and shallow understanding of physics does tell me that since the LED bulbs are running so much more efficiently and using so much less energy -- that overall heat output must be significantly less, regardless of whether the fins burn your hand or not :)
But I could be wrong and I'd love to hear more from people who know. If I am wrong, then i have just poured a bunch of money down the drain for little good reason.
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Regarding the heat...
Light bulbs are hideously inefficient. Almost 100% of the input energy is converted to heat. And the improved bulb technology (tungsten incandescent -> CFL -> LED) is the result of improving on that efficiency.
But in any case, the amount of energy emitted by a lightbulb in the form of light is pretty tiny. Viewed another way, wiring up fifteen, hundred-watt incandescent bulbs is almost indistinguishable from a space heater. At the end of the day, the amount of heat you're going to generate is pretty much the wattage of the bulb, regardless of technology.
LED bulbs use far less watts, but still get hot. I believe that's because the LED is soaking its heat into a much smaller area. So an incandescent is making more heat and radiating it out through a relatively larger area. An LED makes less heat, by generating a similarly high temperature but radiating it out through a smaller area (so that if you touch a fingertip-sized area of each device, they feel about the same).
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The heat fins do get very hot.. Though that doesn't definitively tell us about heat comparisons.
My limited and shallow understanding of physics does tell me that since the LED bulbs are running so much more efficiently and using so much less energy -- that overall heat output must be significantly less, regardless of whether the fins burn your hand or not :)
But I could be wrong and I'd love to hear more from people who know. If I am wrong, then i have just poured a bunch of money down the drain for little good reason.
-mouser
I don't remember much of my high-school physics either, and I was mercifully spared in college. So I may be talking nonsense. But if I remember what little I do correctly, the total amount of heat generated by any electronic device is a function of its resistance, not the interplay of voltage, wattage and amperage. The efficiency of the bulb is due to reduction of wattage (don't know about the amperage, input voltage is obviously the same). But considerable heat can be generated at very low power, if resistance is high enough. Even a small flashlight bulb gets pretty hot when illuminated for a few minutes. Indeed, it's the heat produced by resistance that generates the incandescence. LEDs are more efficient because they use less total power throughput relative to incandescents to produce a roughly equivalent number of photons. This all seems pretty obvious. What is not obvious to me is why so much heat is still produced. Is the LED driver the equivalent of a step-down transformer? I think that would account for it.
I understand your desire to reduce heat - I have a similar problem in my place in the summer. I, too, thought they would run much cooler and was surprised to feel the high heat of the fins. But I wouldn't lament too much if you don't get the reduction you expected - if the bulbs perform as advertised, they will pay for themselves many times over. And surely someone has made this heat comparison somewhere. Have to see if I can dig it out.
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Fascinating post on electrician forum:
http://www.electriciantalk.com/f8/misconception-leds-produce-almost-no-heat-leds-require-massive-heatsink-24168/
"...Incandescent lamps reject heat through invisible infrared radiation. LEDs dissipate heat almost solely through conduction, therefore it gets hotter at the fixture... "
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So this stuff actually gets back to my question:
I have (ceiling) light fixtures that state very clearly "MAX 60W [incandescent] BULB". So one of the motivations for me moving to LEDs is the ability to run brighter LED bulbs that give off lumens equivalent to a 100w incandescent. But to be honest, I don't really know what that limit on the fixture is all about.
It seems from what I'm reading now that this 60W limit is not so much about electricity limit, but about how much heat the fixture bases can take. And if that's true, and LED bulbs generate huge heat at the fixture base, I may be in trouble.
Also: http://www.edn.com/electronics-blogs/led-insights/4423570/That-60W-equivalent-LED--What-you-don-t-know--and-what-no-one-will-tell-you-
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I just picked up a few of those lollipop-shaped Phillips LED "bulbs" from Home Depot. On sale for $3 and change.
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I have one in the ceiling light over the kitchen sink. It looks nice and doesn't seem to throw any heat.
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Don't know what the base is doing temp-wise. If I ever get my IR thermometer back I'll have to check it. The CFL lamp that was in there has a discolored base from the heat its ballast generated.
Also found this shot of the inside of one of these bulbs.
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Which is great because I was very tempted to crack one open just to see what was inside. $3 saved! :Thmbsup:
I can't help thinking a time will come when we'll need to liberate these lamps from AC because the inefficiencies of converting 110v down to what the LEDs need is a waste. I have seen some vacation-type homes wired for regular AC (required by building code) and low-voltage DC for things powered by the solar panels on the roof. I think as time goes on we'll see more of this. Possibly with the electrical mains remaining the way they are - but with only a small number of outlets to provide 110v or 220v AC to less efficient devices like clothes dryers, convection and microwave ovens, air conditioners, etc. The rest of the outlets, that power everything else, will be low-voltage DC driven by a single transformer/regulator located in the basement.
8)
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Update: it's been in for a few hours now and it's warm. If I put my fingers on the ring around the 4 o'clock mark, I can keep them there about 3 seconds before I have to move them. It's definitely hot enough to burn.
Oh well! So much for the heat reduction. The CFLs are definitely running cooler. The lamp base is equally hot - but at least the CFL tube was touchable. Not so the LED ring. :(
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On the other side of the LED issue...
I do a fair amount of work in the semi-conductor industry, and LED lighting is a good part of that.
Going forward, what you need to be aware of is that LEDs ARE SEMI-CONDUCTORS. This is important.
The capabilities of lighting devices will expand well beyond "lighting" in the future. Any number of different sensors can be included with them.
Expect LED lighting to include more sensors, and to have the capability to spy on you. It will happen. Just keep your eye on the added "benefits" that they tout in their marketing.
I'm well aware that a good number of people here think that I'm a paranoid conspiracy theorist. You wouldn't if you saw what I saw. I get to look at internal documents that aren't public. As an example, I recently had a document come across my desk from a large semi-conductor manufacturer talking about how they were near ready to distribute tracking chips designed to be embedded in people. This is almost not-news at all. It has been reported for many years, and the technology is near ready for large scale deployments.
LED lighting has huge potential. It can recreate what looks like sunlight. The range of light that it can replicate is astounding. The development kits for lighting device manufacturers are becoming more and more robust with lighting being able to be upgraded through simple engine replacements rather than through complete redesigns.
But... it's a Trojan horse. Make sure your horse is empty before you let it through the gates.
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I don't know if it will be of any consolation, but: all three of my installations are base-down. (I use the desk lamp on my nightstand, but rarely read in bed, so it's almost always pointed upward for indirect lighting.) In this position, the socket fixtures themselves remain at or near room temperature, so the fins clearly do a pretty good job, and I personally would not hesitate to strech 60 to 100 in this configuration. Base-up? Perhaps in a ceiling fan that you run all the time when the light is on, forced convection would cool to a reasonable level. But my fingers tell me that in any shaded base-up installation, it would just have to get damned near as hot as an incandescent, even with otherwise unrestriced airflow.
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But if I remember what little I do correctly, the total amount of heat generated by any electronic device is a function of its resistance, not the interplay of voltage, wattage and amperage
-Sarkand
I think you're overthinking it. It just comes down to basic conservation of energy. The amount of energy you put into the device is the same as what comes out of it. The only question is in what form is the energy emitted? But since we're looking at devices that are emitting roughly the same amount of light, we can even discount that portion of it to compare the total amount of heat generated
Technically, the total amount of energy being expended easy to figure. In the USA, the voltage should be 110V. The amount of electrical energy you're putting in is the amps, which you can calculate by dividing the bulb's wattage by the volts. We don't just how much is being turned into light, but it's a small number and similar across all the devices anyway. So it's a decent estimate to compare the relative amount of heat generated as the relative wattage of each device.
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Last year I replaced my kitchen under-cabinet lights (P11s) with LEDs.
These are the strip type lights and can be custom made in whatever lengths you require, although Walmart carries them now in varying lengths.
They required 12 volt DC current and a 110 to 12 volt adaptor (5 amps) was installed to supply same.
I reused the swithes from the original P11 fittings to operate each light individually, and am quite happy with the coolness of the fixtures and the lighting spread afforded.
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It seems from what I'm reading now that this 60W limit is not so much about electricity limit, but about how much heat the fixture bases can take. And if that's true, and LED bulbs generate huge heat at the fixture base, I may be in trouble.
-mouser
This is quite true, but there are caveats. For instance, my ceiling fixtures say 60W only, no higher. However, they are embedded ceiling fixtures with a frosted glass cover. The 60W limit is not only due to heat, but also due to bulb burnout in an enclosed environment. I can put a 100W incandescent in the fixture, but it will die of heat exhaustion in about a third of the time that a 60W will last. With the CFL or LED bulbs, an infrared thermometer shows a significant captured heat reduction. CFLs show less temp than the LEDs, but as was mentioned earlier, they're a lot more damaging to the environment. Well, at least we know that particular damage - LEDs have yet to be EPAed :-\.
I also used the IR gun on several desk lamps. Heat reduction, compared to an incandescent, has been fifty to seventy-five percent, depending upon the number of LEDs involved in a particular lamp.
Most telling point is that over a two (2) to three (3) year period, I've seen a significant reduction in the electric bill, ~20%-25% in winter and ~30%-40% in summer. That has made the conversion process more than financially attractive :Thmbsup:.
Note: I know more than I ever wanted to learn about this because of a stupid question I asked once in an electronics class :'(.
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I reiterate: the heat in an electrical system is generated by resistance. Wattage, voltage and amperage have nothing to do with it, except in how they influence resistance (push more of any of these into a medium of given resistance and more heat will be generated). You can throw 10,000 watts at 100,000 volts across a superconducting wire or surface and generate little or no heat - resistance is reduced to near zero in such conditions. At absolute zero, resistance of a conducting medium is zero, this is a law of physics - I haven't forgotten that much. The heat is generated by the excitement of atoms unwilling to give up their electrons in order to propagate a current. If the current is high enough, the wave is propagated - at the expense of the heat generated when the atoms are forced give up their electrons, as they have to be raised to a higher energy level in order to do so. In the trough of the current (wave), the atoms regain their lost electrons from the free electrons surrounding, ready to repeat the cycle at next crest. At least that is how I understand it.
My question in fact relates to the mechanism by which the heat (resistance) is still generted at such high levels, even in conditions of lower wattage. I still like my earlier guess of a step-down or AC/DC transformer. These things produce heat like crazy - to get rid of the extra electrons, I expect.
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the heat in an electrical system is generated by resistance. Wattage, voltage and amperage have nothing to do with it, except in how they influence resistance
-Sarkand
No, these are all parts of the same trinity.
VOLTS x (VOLTS/OHMS) = WATTS
We know volts is 110V. And rearranging the equation gives us
OHMS = VOLTS ^2 / WATTS
So given a constant voltage of 110, talking about Ohms and Watts are really just two sides of the same coin. You can't say they've got nothing to do with each other.
For a much better discussion, see http://amasci.com/elect/vwatt1.html. From that page (emphasis mine):
Conductive objects are always full of movable electric charges, and the overall motion of these charges is called an 'electric current.' Voltage can cause electric currents because a difference in voltage acts like a difference in pressure which pushes the conductors' own charges along. A conductor offers a certain amount of electrical resistance or "friction," and the friction against the flowing charges heats up the resistive object. The flow-rate of the moving charges is measured in Amperes. The transfer of electrical energy (as well as the rate of heat output) is measured in Watts. The electrical resistance is measured in Ohms. Amperes, Volts, Watts, and Ohms.
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Interesting development for LEDs:
http://www.cbc.ca/news/canada/kitchener-waterloo/waterloo-chemist-develops-holy-grail-led-lightbulb-1.2648126
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Radovanovic's lab at the University of Waterloo has used chemically-modified nanoparticles to tune LED light to a specific hue, rather than using expensive rare-earth elements to offset the natural blue, red or green light emitted by LEDs.
...
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Excuse me, but this only reinforces my point. Sliding the players around is only a different way of saying the same thing, that's the beauty of mathematics and physics. Ohms do not equal watts, they are not two sides of the same coin, i.e., manifestations of one another, they have a relationship. I have granted the influence of wattage on ohms - greater wattage given constant ohms will increase heat output. Yes, heat can be measured in watts of power, but that heat is generated by resistance, and that's how thermodynamics works in Newtonian physics.
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Folk,
Several of you have made excellent theoretical points, and I understand the theories behind them to an extent. However, none of those points are borne out by my electric bill reduction. The realities kinda kill the theories in such discussions. Financially, LEDs have altered my budget. That is fact, and no theoretical discourse will alter it.
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Folk,
Several of you have made excellent theoretical points, and I understand the theories behind them to an extent. However, none of those points are borne out by my electric bill reduction. The realities kinda kill the theories in such discussions. Financially, LEDs have altered my budget. That is fact, and no theoretical discourse will alter it.
-barney
Yep, ain't no doubt about it - LEDs will save energy, whatever the long-term costs in various applications. That is important. But we have let this thread go way off topic (mea maxima culpa, Mouser). Mouser's stated primary motivation was heat reduction, however and wherever it is generated. The cost of energy saved is gravy to him. Unfortunately, he is now in the position of re-thinking his original assumptions, as am I. The fact is that LEDs use less energy, that is important, and I intend to keep using them as the best alternative until something better comes along. I am willing to pay the freight (still think it's cheaper).
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There is no question whatsoever that LEDs use less electricity and will therefore save you on your monthly electricity bill.
Of course that still doesn't quite tell you whether you will make back your initial purchase price -- that will depend on how long you stick with your bulbs before upgrading; but given the high price of electricity it won't take long before you do.
As Sarkand says, the heated discussion here hasn't been about saving money, but about other issues involving LED bulbs -- most recently about the heat generated vs incandescent bulbs.
I have raised heat as an issue for two reasons: First, because I wish to reduce the heat added to the house by the bulbs during the summer, and second, because I wish to run brighter bulbs in light fixtures that are rated at 60w.
I think to sum up what we've sussed out:
- The wattage of a bulb (whether it be incandescent or LED) is probably a very good measure of the heat being added to the environment; so an efficient 10 watt LED is going to be warming the room a lot less than a 60 watt incandescent bulb. So far so good. This addresses concern number one.
- However, for some interesting and non-intuitive physics reasons, LED bulbs don't disperse their heat well -- and all of the heat they generate is located right at the base of the bulb (compare this to traditional incandescent bulbs which project heat out into the room along with the visible light) . This is why LED bulbs have special heat sinks on them, and why many LED bulbs are listed as not for use in enclosed fixtures. They generate much less heat, but all of that heat stays right at the base of the bulb. Therefore, it may not be safe to run a much brighter LED in a fixture rated for 60w -- because the heat at the base of the LED may exceed the heat at the base of a 60w incandescent.
- Heat generated at the base of LED bulbs has an additional consequence. Not only because it might exceed the safe range for your fixture -- but because it can cause a very early failure of the bulb itself. So pay attention to the quality of the heat sink on the LED bulb, and whether the bulb is rated for use inside an enclosed fixture. Bottom line for concern #2: If it not enclosed and has a good heat sink, it's probably safe to use a brighter bulb in a fixture rated for 60w.
So, all things considered, LED bulbs do seem to still be a good solution to my concerns about heat and brightness -- with the caveats above.
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The Philips "lollipop" (as 40Hz dubbed it) design is supposed to provide an internal channel to circulate heat away from the base, allowing for a smaller heat sink, and thus a lighter and cheaper bulb.
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Thanks for reminding me of one other thing you have to be wary of with LED bulbs -- they can be HEAVY.
I had to jerry-rig a special support for the bulbs in my kitchen ceiling fan.
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This quote from CWuestefeld does a good job of explaining why i am moving to LEDs:
"Viewed another way, wiring up fifteen, hundred-watt incandescent bulbs is almost indistinguishable from a space heater.."
I do not want to be running a space heater in 100 degree weather.
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Further reports -- The Cree 18w (100w equivalent) bulbs generate very nice light and are a no-brainer for my office.
However, my attempts to replace 6 candelabra bulbs in my dining room with LEDs has been a failure. The bulbs in the chandelier point straight upward and all of the candelabra LEDS i have tried do a terrible job of casting light down.
So it looks like i'm stuck with incandescents in that fixture for now.
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none of those points are borne out by my electric bill reduction. The realities kinda kill the theories in such discussions. Financially, LEDs have altered my budget.
-barney
I don't doubt you, but I'd like to feel out the specifics of it. My suspicion is that you might see a relevant difference in the warmer months, particularly when you're using air conditioning. This part is really easy to believe, because you'd otherwise be paying double for inefficiencies: once to run the heat-generating lights, and again to run the air conditioner to get rid of the waste heat.
But in the cooler months when you're running heat, this is much less clear to me. To a first approximation, I expect that inefficiency in the lighting is essentially free. That is, the waste heat thrown off by the lighting simply replaces the running of your furnace that would otherwise be generating that heat for you. The only loss in winter, then, would be a theoretical difference (that's probably not possible to realize for most of us due to the design of our HVAC system) in improved efficiency if you're using a heat pump for wintertime heat.
More simply: in the summer, inefficient lights bite you twice. But in the winter, I expect that inefficient lights simply allow you to run the furnace somewhat less.
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But in the cooler months when you're running heat, this is much less clear to me. To a first approximation, I expect that inefficiency in the lighting is essentially free.
this is a good point -- though it might be less valid if you have a cheaper way of heating (wood, gas, etc.)
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The design of LED lights is on purpose made to look like the light bulbs everybody knows. That way people are more easily persuaded to buy these. I think 2 or 3 design generations into the future will result in much more efficient shapes for LED light bulbs regarding heat, weight etc. But first the manufacturers need to make enough money to earn back their initial investments, to make it more interesting for them to continue with this type of lights.
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Another caveat i've found with replacing some of my incandescent bulbs is that even if you get an LED that is the same size as an A19 (standard bulb), sometimes the base is thicker which prevents it from screwing in all the way -- and thus will not power on.
Conclusion: Buy your LED bulbs from someplace where you can return them.
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I saw the title of the thread and got all excited, but nobody has addressed the issue that troubles me. I cannot SEE with these awful replacements.
Where I live, it has been almost impossible to find a 100W incandescent for several years. In any event, I knew the end was coming, and so I started experimenting with different bulbs. NOTHING comes close to the efficiency of the now outlawed lighting I have enjoyed all my life.
My experience with LEDs has been even more disappointing than my experience with CFLs. Because the little desk lamp in my computer room, with its tiny bulb, puts out such nice bright light, I expected the same from whatever LED I put in my reading lamps. But, no. I cannot see. I read. I write, I work cross-word puzzles. I sketch. I paint my fingernails. And, what will happen when those big round bulbs that light my bathroom die? How will I see to apply make-up?
I haunt Lowe’s lighting section. They are tired of me, and my questions, and my returns. Packaging may say “Replaces 100W incandescents” but for light output, that just isn’t so. I don’t care about heat. I don’t care about electrical usage. I don't care about life span. I just want illumination.
For my reading lamps, which is what I really care about, 1600 lumens should work, but part of the problem is what Mouser said here:
3. Spotlight effect. The LED bulbs are more directional -- which can be especially troublesome for fixtures where the bulb is pointing up.
But I’ve also had noise and flicker from both CFLs and LEDs. Horrible, horrible, and no relief in sight.
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@Sazzen:
Perhaps you should consider halogene light?
When I have time, I'll drop by a light shop here in PY. They sell a led light fixture that is shaped like a construction light or flood-light (if that term makes more sense to you). The light surface would have a surface that has a similar size as the surface of an iPad. It's height would be similar to 3 iPads stacked on top of each other. The light is very bright and strong. It doesn't get that hot either. I don't know the type or model nr, so I'll ask. To me it looks like it uses a special type of LED, with a size and shape similar to a computer processor.
Halogene light is something that should be easy to buy all over the world though. That type of light has quite a big range of color, so there should be something to your liking. However, they are not cheap (purchase and consumption) and don't last that long either. Having said that, their light I find much more pleasing than incandescents.
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There's been some lame arguments that the reduction in power consumption from CFL bulbs results in less overall mercury being released into the environment in areas where coal-fired generators are the norm - because less coal (which also contains mercury) gets burned. But that sounds more like an industry thrashing around to find something - anything - to throw up against the fact that no level of mercury exposure is ever good for us.
-xtabber
I totally disagree. Less mercury is less mercury, and CFL's are easily recycled where I live.
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Been hunting for an LED light that can be used on [covered] front porch. Needs to be reasonably weather resistant, if not weatherproof. Also would be nice if it had built in light sensor so I don't have to remember to turn it on - or off! - but I might be reaching a bit there :-\. Corpus, while comfortable, is not a shopping metropolis :tellme:, and I'm not having a great deal of luck searching online. Any suggestions?
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Been hunting for an LED light that can be used on [covered] front porch. Needs to be reasonably weather resistant, if not weatherproof. Also would be nice if it had built in light sensor so I don't have to remember to turn it on - or off! - but I might be reaching a bit there :-\. Corpus, while comfortable, is not a shopping metropolis :tellme:, and I'm not having a great deal of luck searching online. Any suggestions?
-barney
Lowes has a couple of variations on that theme that screw into the bulb socket, and then the bulb screws into them:
http://www.lowes.com/pd_314356-207-SLC5BCBL_0__?productId=3354048&Ntt=motion+light+switch&pl=1¤tURL=%3FNtt%3Dmotion%2Blight%2Bswitch&facetInfo=
http://www.lowes.com/pd_319729-207-OMLC3BCL_0__?productId=3125511&Ntt=motion+light+switch&pl=1¤tURL=%3FNtt%3Dmotion%2Blight%2Bswitch&facetInfo=
http://www.lowes.com/pd_314356-207-SLC5BCBL_0__?productId=3354048&Ntt=motion+light+switch&pl=1¤tURL=%3FNtt%3Dmotion%2Blight%2Bswitch&facetInfo=
http://www.lowes.com/pd_175358-207-MLC9BCL_0__?productId=3335380&Ntt=motion+light+switch&pl=1¤tURL=%3FNtt%3Dmotion%2Blight%2Bswitch&facetInfo=
http://www.lowes.com/ProductDisplay?partNumber=432531-1353-45168&langId=-1&storeId=10151&productId=4435623&catalogId=10051&cmRelshp=req&rel=nofollow&cId=PDIO1
http://www.lowes.com/ProductDisplay?partNumber=141611-207-SLC6CL&langId=-1&storeId=10151&productId=3125287&catalogId=10051&cmRelshp=req&rel=nofollow&cId=PDIO1
I've had similar motion sensitive widget on my front porch for the a few years now. Walk up, the light comes on. Walk away the light goes off in about 10 minutes. And the best part is, I do nothing. :)
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Might be useful. Very informative notes here from Michael Herf - the guy who I gather is the author of f.lux (https://justgetflux.com/) (which I have used for a while now) and the original author of Picasa: - notes on Full Spectrum lighting. (http://stereopsis.com/fullspectrum/)
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Just reporting in that I'm still quite happy with my switch-over to LED bulbs.
A few observations thought:
1. I've had quite a few go bad. CREE (manufacturer) replaced them though i had to pay shipping to send them the bad ones. They seem to go bad in certain fixtures and not others.
2. I have a couple of Phillips ones that do a good job of lighting, but make a buzzing noise. Very annoying.
3. Soft White is the only way to go, the cool temp bulbs get annoying very quickly.
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Just reporting in that I'm still quite happy with my switch-over to LED bulbs.-mouser
Have you noticed any savings in electricity costs?
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Well, i haven't paid attention but there can't be much doubt about their being significant savings since i had a 6-12 100w incandescent bulbs on at any given time.
Whether the savings make up for the high up front cost I don't know.
But if you read my first posts you'll see that my main motivation was to decrease the HEAT generation that was contributing to summer overheating, and in that respect I think i can anecdotally report an improvement.
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I'd forgotten about this thread.
I saw the title of the thread and got all excited, but nobody has addressed the issue that troubles me. I cannot SEE with these awful replacements.
Where I live, it has been almost impossible to find a 100W incandescent for several years. In any event, I knew the end was coming, and so I started experimenting with different bulbs. NOTHING comes close to the efficiency of the now outlawed lighting I have enjoyed all my life.
My experience with LEDs has been even more disappointing than my experience with CFLs. Because the little desk lamp in my computer room, with its tiny bulb, puts out such nice bright light, I expected the same from whatever LED I put in my reading lamps. But, no. I cannot see. I read. I write, I work cross-word puzzles. I sketch. I paint my fingernails. And, what will happen when those big round bulbs that light my bathroom die? How will I see to apply make-up?
I haunt Lowe’s lighting section. They are tired of me, and my questions, and my returns. Packaging may say “Replaces 100W incandescents” but for light output, that just isn’t so. I don’t care about heat. I don’t care about electrical usage. I don't care about life span. I just want illumination.
For my reading lamps, which is what I really care about, 1600 lumens should work, but part of the problem is what Mouser said here:
3. Spotlight effect. The LED bulbs are more directional -- which can be especially troublesome for fixtures where the bulb is pointing up.
But I’ve also had noise and flicker from both CFLs and LEDs. Horrible, horrible, and no relief in sight.
-sazzen
And...
3. Soft White is the only way to go, the cool temp bulbs get annoying very quickly.
-mouser
I'm the opposite - I like cool white. It's easier to read and see with.
Cool white is closer to natural sunlight, while soft white is closer to the light cast by fire.
@sazzen - Grab this piece of software (recommended by @IainB):
https://justgetflux.com/
Play with it and see how the colour temperature drastically affects your perceptions.
My bet is that you'll fare better with high colour temperature lighting. Look for 5,000K to 6,500K or so. Those should be better for you to see/read/etc.
Incandescent lamps have a high CRI, which means they have a fuller light spectrum. CFLs and LEDs tend to have large gaps in their colour spectrums, and that makes visibility harder.
You'll need to do some research, but check into lamps with higher CRI ratings -- those will likely also help you out better than lower CRI rated lamps. As your minimum, look for lamps with a CRI of 80 or higher. Ideally, you want 100, but consider finding something around 90 as awesome.
Regarding the spotlight effect, LEDs come in a broad range, from 20 to 120+ degrees. Part of that is the lens used for the LED lamp. Bead and SMD lamps have broader dispersion than the 20~30 degrees of "hat" LEDs, though those can also be up to around 45 deg. So, there's a pretty wide range out there -- it depends a lot on the specific device and how it is built.
Here are some sites that get into a lot of detail about lighting:
http://www.ceolas.net/
http://freedomlightbulb.blogspot.com/
http://freedomlightbulb.blogspot.com/p/resource-links.html
http://greenwashinglamps.wordpress.com/
There's a good amount of science in those to explain why incandescent lighting is better for some purposes.
This page here is absolutely ESSENTIAL reading:
https://greenwashinglamps.wordpress.com/lamp-comparison-overview/
The charts are very informative.
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Interesting. My problem has to do with physical configuration :(
Have a spider lamp in the living room which uses 40W or 60W bulbs about the size of a golf ball which also has candelabra sockets. No can find anything in the LED arena which will fit.
Bed lamps on the headboard have a standard (?) socket, but needs flame-shaped bulbs in order to lift off the glass mantle for replacement. (Yeah, I know, but even LEDs require replacement after a time - who knows, I might even live that long :-\.)
Have a couple of desktop LEDs, one (1) clamp-on, one (1) desktop, over two (2) of the compter desks. Adequate for typing, but inadequate for writing deposit slips or checks.
Biggest problem so far, however, is finding a functional chart - yes, I've searched - that equates watts to lumens. I'll get an LED home that I think will work, but the light output is inadequate. Colour balance is part of that problem, yet not the whole problem. The directional issue is something I can deal with, for the most part, considering the nature of my ceiling fixtures (recessed, glassed over), but so far CFLs work reasonably well there.
By and large, my biggest issue with LEDs is equating light output 'tween watts and lumens. Well, that and the fact that I've spent over a couple of hundred dollars experimenting - that's a pretty large expenditure for light source experiments that don't involve a nuclear reactor :-\ :P.
Haven't had time yet to check those links, but as soon as we're through with the sailboats (annual maintenance, helping a friend who has a sailing school here), I'll check 'em out.
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Lumens measure light output and Watts measure energy input. They are two different things altogether.
When you see an LED bulb listed as "60 Watts equivalent" that means that it puts out light equivalent to the light put out by a 60 Watt incandescent bulb, but that's rather imprecise. Different bulbs can put out different amounts of light for the same amount of energy. Many manufacturers list light output in Lumens on their packaging, which is the most reliable measure to judge by, but perceived brightness depends on many other factors like light temperature (higher temperatures equate to cooler light which is brighter to the human eye) and color rendition index (CRI).
A very quick rule of thumb is that LED (and CFL) bulbs produce 4 times as much light as a tungsten incandescent bulb using the same amount of electricity, but that can vary quite a bit. Here's a Watts to Lumens calculator (http://www.rapidtables.com/calc/light/watt-to-lumen-calculator.htm), but it's only as accurate as the efficiency of the individual bulb, which as noted above, can be highly variable between manufacturers and product lines.
As for candelabra base (E12) and flame shaped standard base (E26) bulbs, I had a hard time finding them a year ago, but no more - there are now many choices available. Searching for candelabra base LED bulbs on Amazon will bring up dozens, and they seem to be readily available at my local Home Depot and Walmart too. You can also get inexpensive E12 to E26 converters (http://www.amazon.com/JACKY-LED-5-Pack-E12-Adapter/dp/B00L595FA0) to use standard base LED bulbs in candelabra sockets.
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I have not had great experience with candelabra LEDs.
The biggest problem is if you have a candelabra fixture where the bulbs are mounted facing upwards. A traditional incandescent candelabra shines a ton of light downward, but this is not the case with ANY LED i have come across, and it's much worse with candelabra LEDs where the base inevitably blocks most of the light.
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The biggest problem is if you have a candelabra fixture where the bulbs are mounted facing upwards. A traditional incandescent candelabra shines a ton of light downward, but this is not the case with ANY LED i have come across, and it's much worse with candelabra LEDs where the base inevitably blocks most of the light.
-mouser
True, but candelabra fixtures are the least efficient way to light an area anyway. The main reason to use them is for decorative purposes. Candelabra chandeliers look more and more like relics from the past, but I have found that I actually prefer LED candelabra flame bulbs to incandescents in some wall sconces, for the very reason that the light spreads better horizontally than below the fixture.
Also, the lighting fixtures for most ceiling fans now seem to require E12 (candelabra base) bulbs, possibly to prevent people from putting high wattage bulbs in them. That's one situation easily resolved with E12 to E26 adapters -- you don't want flame bulbs there anyway.
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I was going to post this in the basement where we have a discussion about lighting, but I think it has some broader appeal, and this thread might be good for it.
http://cynic.me/2015/10/31/soldering-the-wrong-leds-into-the-right-fixture/
Just me soldering some lighting fixtures to work after I screwed up.
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I have not had great experience with candelabra LEDs.-mouser
Hay, at least you have it narrowed down to a specific instance. Despite having carried an LED flashlight for the past several years, I cannot for the life of me get past the - mentally hardwired - perception that without the cast of yellowish incandescent light I can actually see what I'm looking at.
But more on topic-er-ish...
The biggest problem is if you have a candelabra fixture where the bulbs are mounted facing upwards. A traditional incandescent candelabra shines a ton of light downward, but this is not the case with ANY LED i have come across, and it's much worse with candelabra LEDs where the base inevitably blocks most of the light.-mouser
Two different ideas come to mind:
1. (assuming the ceiling is while) Can you go with a brighter/harsher version of an LED bulb pointing straight up and work with the indirect/reflected light from the ceiling?
2. (This one is aesthetically subjective) Can you take down and disassemble the fixture, and then reassemble it with the bulbs pointing down ... without making it look completely horrid (or electrocuting yourself for that matter)?
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2. (This one is aesthetically subjective) Can you take down and disassemble the fixture, and then reassemble it with the bulbs pointing down ... without making it look completely horrid (or electrocuting yourself for that matter)?
-Stoic Joker
no this is an antique dining room chandelier with shades.. however, it's not so precious and i think the solution is to replace it with a nice big ceiling fan with normal sized LED bulbs.
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Lumens measure light output and Watts measure energy input. They are two different things altogether.
When you see an LED bulb listed as "60 Watts equivalent" that means that it puts out light equivalent to the light put out by a 60 Watt incandescent
-xtabber
Yes, they are two (2) different things. However, both lighting elements require energy input of the same nature. What I seek is a table, chart, nomograph, call it what you will, that provides me with some equivalency of output. Many of the LEDs I've seen do not offer that information on the packaging. (I'd also like to know the energy consumption of a given luminosity.)
As mouser mentioned, the significant cause for his research was heat. Since most of my room lighting is enclosed, that is also a concern for me, mostly in regard to service life. So the question becomes, in part, can I put a greater light source in the same enclosure? If so, how long might it last? These are not questions I would normally ask of the seller, particularly an online seller against whom I's have little opportunity for redress.
Aside[ If they stop making incandescents, what happens to My Little Oven?]
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can I put a greater light source in the same enclosure?
-barney
This relates to both heat and also electrical current (limited by wire gauge in a light fixture). I think LED bulbs are awesome because I can put a "60W equivalent" bulb in old lamps that specify no more then 25W!
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Buddy replaces lighting in a garage.