LED light bulbs

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This topic contains 24 replies, has 12 voices, and was last updated by  ballardMike 3 years, 11 months ago.

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  • #75560

    Shelley
    Moderator

    The LED replacement bulbs have finally come down in price to where they’re almost reasonable with 60 watt incandescent replacements coming in at roughly $10 for two at Costco.

    But am I the only one who finds it difficult to read with them? Looking at the package, it says 2700 K, yet a compact fluorescent which says 2700 K is way easier to read with. So what gives? Why the difference? My eyes are old and tired, and the LED bulbs make them feel even more tired, and my vision less acute.

    #75562

    Richy
    Participant

    I have replaced all the bulbs in my house, well worth it!
    Homedepot has a nice display in the light bulb section with a temp # examples.
    They also have a much better selection then costco and competitive prices and 3 way leds also.

    #75563

    boatgeek
    Participant

    The only thing I can think is that the 60 watt “replacements” have different light outputs. You probably know this already, but the 2700K is the “warmth” of the light, with a lower number being a little more yellow and a higher number being whiter/bluer. If you still have the packaging, you might be able to compare lumens, which is the total light output.

    FWIW, we just replaced CFL bulbs with 75-watt replacements (sorry, don’t have the packaging for lumens anymore), and they are really nice and bright. Whatever you do when comparing bulbs, don’t go to Lowe’s. The display is crappy and the guy I talked to in the lighting department didn’t know the difference between watts, lumen, or color temperature.

    #75565

    Shelley
    Moderator

    Thanks Richy and boatgeek. I don’t really understand why bulbs with the same specs for output and temperature feel so different when it comes to reading. Here are the specs for the bulbs:

                     LED              CFL
    Lumens           850              850
    Temperature     2700 K           2700 K
    Energy used      9.5 Watts         13 Watts
    Life            22.8 Years        9.1 Years

    The CFL bulbs came from Costco, and the LED bulbs came from Home Depot about a month ago. These are both 60 Watt equivalent bulbs. There were 2 choices at Home Depot for the LED color temperature 2700 K and 3000 K. I stuck with the 2700 K for the warm color compared to the 3000 which seemed bluish to my eyes.

    #75569

    phoo
    Participant

    Does the light LOOK like the same color to you? I remember hearing long ago that although there’s a temperature rating for the light, it’s not as exact as it looks.

    BTW, I used to LOATHE the whiteness of CFLs. They seemed so cold and harsh. But after giving myself some time, I actually prefer it now. And I can see better when I read paper books.

    Could you be more specific about the error you experience when trying to read with the LED light? I know it’s likely difficult to quantify, but it would be more information that folks might be able to use to take a stab at the possible cause.

    In a very cursory search, I turned up a couple differences with LED bulbs. Supposedly they are supposed to help eye strain because they don’t flicker. They also don’t contain UV. However, they are also a directional light source, so perhaps there is less light making it to your book than from the CFL.

    Personally, I’m not ready to transition to LED bulbs yet. Ok, I’d be fine replacing my “ordinary” bulbs: the ones in my kitchen, bedroom and bathroom, except for the expense. But I’ve got a 7000 lumen bulb that I would highly doubt could be replaced by an LED bulb at this point, and I couldn’t afford it if they did make such a beast. I treasure my “indoor sun” during the winter months.

    #75571

    Cate
    Participant

    Light bulbs have become just one more thing I don’t understand… But the silver lining is that if they last for twenty one years I won’t have to buy that many more.

    #75572

    Richy
    Participant

    One other real nice thing about LED’s is bugs are not attracted to them. Able to have lights on and windows open with insects flying around.

    I do have a 2700 lum in my kitchen (uses 40w) and I no longer need under-counter lights.

    Shelley, one difference in the bulbs, that may be what you notice when reading, is CFL are a gas discharge (compact florescent lamp) and have a flicker – that is not really noticeable to most folks and LED’s are DC powered and should have no flicker at all and if designed well will have no change in brightness over it’s entire life or flicker with variations in voltage in an older home (should be no variations in a newer home), also 22 years life is just a guess should last over 35 yrs.

    #75585

    Shelley
    Moderator

    +1 Cate :)

    Richy, I know that flicker well. The 60 Hz flicker I can check the turntable speed with. There is also the variable flicker which comes from starting up in the cold like my garage. So far, I’m preferring the CFL bulbs for reading.

    Phoo, I don’t know it is an error so to speak. My eyes tire more quickly with the LED lighting and I find I can’t read as late, focusing is a little harder. The color of the lights seems the same, but a spectrophotometer I am not. I imagine an incandescent bulb would yield a gaussian, bell-shaped curve weighted off to the red end and into the infrared. Imagining again, the fluorescent has phosphors coated on the tube which emit light at a defined number of somewhat specific frequencies, so maybe the bell shaped curve morphs into several such curves which are overlapped. Completely out of my league, I now have the idea the LED bulb might be emitting at very specific frequencies with a sharp falloff to the edges of each rather than a bell-shaped drop off?

    I’ve tried the experiment now with two different lights. The first is a torchiere which takes 3 bulbs, and all of the light is bounced off the white ceiling. The other is an end-table type reading lamp which takes one bulb, and the light shines directly on the printed page. In both cases the CFL bulbs are more comfortable to read with. Interestingly enough, I prefer the LED bulbs every place else in the house (no little buzzing noises, they’re dimmable, instant on at full brightness, etc.)

    I’m 64 and I’ve got the beginnings of cataracts which don’t need operating on for “a long time” according to the ophthalmologist. I wonder if the spectrum of the LED bulbs has more blue somehow and that’s getting scattered around by my lenses beginning to cloud.

    #75602

    Richy
    Participant

    Here is a link to some spectrum graphs – you may want to look up cataracts and spectrum.

    http://www.soundandvision.com/content/led-vs-cfl-bulbs-color-temp-light-spectrum-and-more

    I had one cataract repaired and a multifocus lens put in a few years ago and the spectrum of light is much broader with my new eye then it is with ‘old eye’

    #75621

    SunsetHillMarauder
    Participant

    The Cree LED 60W Equivalent Soft White (2700K) bulbs are available at Home Depot. I have had these bulbs for a year or so now and they are very nearly identical in their color output to that of traditional incandescent bulbs. There is a very minor difference in the lumen output between these bulbs and incandescents, but it is so minor as to be no sort of issue whatsoever. I can still comfortably read and do other activities without any sort of eye strain. I have not seen a better LED bulb to date, and would highly recommend this one. I believe they also have a 100w equivalent for sale now for under $20 a bulb. The 60w is under $10.

    #75654

    Mondoman
    Participant

    I currently use two types of LED bulbs. The first are ceiling “can” floodlights, over kitchen counters and such; the second are softball-sized (4″?) globes above mirrors in the bathrooms. The flood lights are pretty expensive even in their incandescent versions, so the LED ones seem quite well-made, and cost about $30 apiece when I bought them a few years ago. With all the LEDs at one end facing the same direction, the design is pretty straightforward. They’ve got fancy integrated lenses to diffuse the LED light somewhat, but still keep it in a 75 degree or so light cone.

    The globe lights, which I bought in the last year, were about $5 each, and are much tougher to design, since they’ve got to shine roughly equal-intensity light out the top and to all sides. Usually, the maker starts by putting one LED facing outward from the top, and 3, 4 or more facing outward from the sides. Then, they use lenses and/or translucent panels to diffuse the light and try to produce an overall even illumination. CFLs, on the other hand, just have their tube massively contorted inside the globular shell, almost like the confinement electromagnets in a magnetic fusion chamber. The CFLs, depending on the tube’s contortions, have brighter and darker areas in different directions.

    Perhaps you got used to the bright spots of your CFL and the LED’s different pattern is causing problems. You can always try the next-higher brightness level — 75w equivalents.

    As for longevity, I’ve already had 4 of my 7 LED ceiling floodlights fail on me during the past 3 years (all replaced under warranty); these were three different brands, but I’ve not had any fail in the last year, so I hope the manufacturing/design quality is now “good enough” for real use.

    #75666

    Salmon Bay
    Participant

    I’m sticking with incandescent. My 1910 bungalow has all historical lighting, and I just can’t put in fluorescent or LED lighting. I went out and bought up a few cases of incandescent bulbs in all wattages; I think I’m set for life…

    #75676

    Angeline
    Participant

    I’ve bought lots of the 60-watt-like Cree bulbs, and also some of the flat ones made by Phillips. I’m pretty happy with the brightness, and some of our house wiring is old and I think benefits from having less draw on it. I do wish there was something affordable in the LED world that was more like a 75 watt incandescent bulb. We used to keep those in the “reading location” lamps and I may have to go back to them for the winter months.

    #75677

    phoo
    Participant

    The link Richy posted is fascinating. It’s really interesting to see the spectrum of each sort of bulb.

    Do they make LED lights that are 5000-5500K?

    #75678

    Richy
    Participant

    Yes, I have one 1000 lum 5000k in my master bath , it is like turning on the sun, we love it , my wife says it makes putting on make up and whatever easy the bulb was priciey but fig 20 years not so bad.

    I think that some day soon when buying a house you will need include light bulbs in the offer

    #75681

    Catherine
    Participant

    What kind of bulb life are people actually getting out of these bulbs? We date when we put bulbs in, and CFL’s rarely go more than a year, and LEDs are pretty spotty too – 3 months is the shortest so far, 2 years is average, for a $15 bulb. Doesn’t seem to matter the source HD, Ikea, Lowes, online… and we have a newer panel and wires. And it’s not like lights go on off a ton here.

    #75683

    Shelley
    Moderator

    Interesting. After reading all of your much appreciated replies last night, I thought there’s something rotten about the label information. Sitting down with a friend and a couple of stiff drinks (Maker’s Mark), I devised a plan. Drinking and a plan – sounds like trouble to me. Lacking scientific type equipment, how does one measure light output? Oh, yeah, that trusty old 1973 vintage Pentax Spotmatic will do it, it has a light meter. Piece of white poster board, shine light in a darkened room onto board, reading from poster board through camera viewfinder, match needle, record f-stop. Switch light to other kind and repeat.

    Bingo! The three LED bulbs each read 1/2 f-stop lower than the three CFL bulbs meaning the light output was approximately three-fourths of the output of the CFL bulbs. So what gives? False advertising of lumen output? But hey, at least a bit of reason for why it was harder to read with them.

    Rummaging around in the basement I found the Killawatt my late husband bought many years ago. Time to check the power consumption. The LED bulbs measured 9.3, 9.3, 9.4 watts. The CFL bulbs measured 13.2, 13.2 13.4 watts. So those are all pretty close to advertised. I recalled that when I bought the LED bulbs, there were several to choose from with nearly the same lumen output, and some had higher power consumption listed on the label, and I purposely chose the ones with lower values. So maybe it is a case of using inconsistent label information to make a purchase decision. Or maybe the CFL manufacturer rated the bulbs at some arbitrary midpoint in their life when light output is lower.

    Short answer, I’ll put those LED bulbs where I’m not going to be doing extensive reading, use the CFL’s in my reading lights, and buy 75 watt replacement bulbs for reading.

    #75684

    boatgeek
    Participant

    I don’t have much data on bulb life for LEDs, since we have a few weeks on the interior lights and a few months on the porch light. My “problem” with the CFLs is that I’m not 100% satisfied with them (mostly the slow startup) and they just won’t die so I can feel good about replacing them. CFLs seem to last better than tube fluorescents for us. We’ve run them for a few years and have only had the porch light die. Maybe we can trade? :)

    We have new wiring and new-ish service in an old house.

    #75685

    Shelley
    Moderator

    Catherine, in one of my businesses I use commercial 105 watt CFL bulbs to replace the old 300 watt ceiling bulbs. I replaced them under a City Light program. I have all the bulbs replaced every 30 months by a service company (due to 20 foot ceilings). Typically of the 32 bulbs, one or two will quit within the first couple of weeks. Then maybe only two or three bulbs will die by the 30 month point. The lights are on 6 days a week from 9 AM to 6 or 7 PM. There are 2 bulbs on constantly in the front of the storefront (never turned off) which interestingly have never died.

    At home, the story is more like yours. The CFLs are lasting one to four years. I don’t have enough sample size on the LED bulbs. The LED in the garage has been there 4 years now, and it hasn’t died yet.

    #75687

    Richy
    Participant

    Catherine, what you say is a bit concerning, do incandescent lamps also burn out in about the same amount of time ? CFL should last years if conditioned correctly ( see below), incandescent should also last years, if not in rough service (jiggled), LEDs do last for an unknown amount of the (the test standards are still working, after about 30 yrs). All lamps can fail in a home for many reasons, temp variation is the most common, voltage fluctuation is the second, OR the LED and CFL bulbs were just manufactured poorly.

    boatgeek, in order to get the CFL lamp to turn on faster and give the max amount of light for the longest period of time, when you first install the lamp, you will need to turn it on and leave it on for at least 1/2 hour – when I had my house relighted (re-lit ?) by city light, I tried what they said and gosh-begone it worked , the light came on instantly at full brightness.

    Shelley, you peaked my interest, LED and CFL have different visible spectrum’s, camera light meters are weighted by the type of expected light, or type of film in the camera (outdoor, indoor) indoor was weighted to the the yellow side of the spectrum and outdoor more to blue side, somewhere, maybe, (I did a purge of old stuff a bit ago) I have a white balanced spectrometer that I used in exposing prints, way before digital and I may try your experiment .

    #75690

    BuffaloHawk
    Participant

    Driving into work I heard a commercial for Seattle City Light offering discounts on LED bulbs. It made me think of this post and just wanted to give a heads up for those interested but unaware.

    http://www.seattle.gov/light/home-lighting/

    Replacing incandescent lighting with energy-efficient lighting is one of the easiest things you can do to save electricity and money. Seattle City Light offers instant rebates on select ENERGY STAR compact fluorescent light bulbs (CFLs), Light Emitting Diode bulbs (LEDs), fluorescent fixtures and LED recessed can fixtures through participating retailers.

    #75739

    Catherine
    Participant

    I have not had problems with the longevity of incandescent bulbs in the same fixtures.

    I forgot to add, that the CFL “par” lights for recessed cans, they are in the 4mo range.

    Boatgeek…you’re on.

    #75771

    phoo
    Participant

    Richy, let me know if you see a 7k lumen LED bulb that is under 3 figures. The CFL that I currently have has been working for a couple years but eventually it will cease and it would be nice to have an either smaller and/or cooler bulb in its place. I figure by the time it does burn out, hopefully LEDs will have come down enough in price and caught up in lumens that it will be an expense I can manage.

    In fact, all the CFLs I use have been in operation for around two years. I did have a fixture in my old place where any bulb in it would burn out within a few months. Sometimes it had a bit of a crackling sound when turned on, but the old CFLs could make noise like that too. One day I finally asked the landlord to have it looked into. He turned on the light with the cover off – something I had never done before. To my horror, the “crackling” noise was a completely loose hot wire arcing to the nearest metal surface, which was the base of one of the bulbs.

    This was an extreme case, but the moral of the story is have your wiring and fixtures checked, Catharine! I know you said the wiring was newer, but something doesn’t seem right. CFLs should last much longer than an average of 6-9 months.

    BTW, for anyone who has installed a CFL in a fixture with a dimmer switch: don’t. I did this, but turned the switch up all the way, so the bulb was never dimmed (thinking that would be ok). It resulted in an expensive bulb ($30) that died in about 3 months, and that was the lucky outcome. It could have potentially started a fire at worst. A CFL has to be specially designed to withstand the dirty signal that a dimmer switch creates. They do exist, but it will run you extra.

    #75779

    Angeline
    Participant

    I bought the LEDs advertised by the electric company. They are great. I like the light quality a little better than Cree, though those are fine also. The shape of the Phillips bulbs is a little odd and won’t work in every fixture. In my traditional lamps with non-clip-on shades they work fine.

    #75800

    ballardMike
    Participant

    I’m a big fan of the Philips flat bulbs for basic lamp replacement and am mightily impressed with the NEW dimmable flood lamps- got a set at COSTCO for reasonable price. Less draw and the light is far better than the CFLs of past years.

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