Criteria for choosing LED bulbs
user-7128712
| Posted in General Questions on
Hi Guys,
I have recently purchased a new house and it already has the lighting fixtures but no lights in it. I have decided to go ahead with installing of LED bulbs and tubes but am unable to decide which ones I should go for..?
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Lots of things to consider here. You already have the fixtures, so at least you don't have to decide on the type of lights.
-price
-longevity (difficult to assess)
-efficiency (lumens per watt)
-intensity - not power, but the actual light output. Make sure it's appropriate for the space.
-colour temperature - personal preference, though definitely avoid high colour temperature in any fixture anyone's likely to use just before going to sleep.
-colour rendering index - higher is better; pretty hard to find any lower than 80 these days but I'd be skeptical of any that don't quote a figure; some visual-philes insist anything lower than 95 is junk, but if you go by that standard then your choices become pretty small.
LEDs bulbs are getting less exotic by the day. Treehugger makes this point here: https://www.treehugger.com/sustainable-product-design/behold-revolution-led-bulbs-are-now-cheap-incandescents.html. Lloyd also notes that you can now buy a dozen 800 lumen Philips bulbs for $25. That price point will allow most consumers to try a variety of bulbs without breaking the bank.
I'd add another consideration: dimability. Most, but not all LED lamps are dimable, but it's not that simple. They require a LED compatible dimmer. One problem is that many LED lamps require a higher voltage to start than to sustain illumination. So, a dimmed light may not start when switched on. Worse, a dimmed light may go out when a momentary high load (like a refrigerator or air conditioner turning on) and stay out. Specialized LED dimmers have a behind-the-switchplate control that the user sets the minimum brightness that solves the problem, which brings up another issue. Many LED lamps simply don't dim that much, even with appropriate dimmers.
Incandescent lamps have a color temperature of about 2700° K however, LED lamps are not convincing at mimicking incandescents at this warm light. Plus, the warmer a LED is the less efficient it is. LED fixture makers seem to be settling at 3000° K. I like this compromise. LED lamp makers don't seem to have gotten the memo and produce mostly 2700° K products.
Most LED lamps have a color rendering index (CRI) of around 80. (incandescents are 100) I recommend 90 plus lamps for the application of makeup so the user has confidence that they will good later under natural light. I also use high CRI lamps where food is prepared and consumed. It makes a big difference in how appetizing food looks. I do not understand why refrigerator manufactures uses high color temperature low CRI lights. Food looks terrible under them.
Thrifttrust is right about choosing the right bulbs and switches if you want to dim your lighting. I spent a small fortune on dimmers for my last house and still had issues controlling light levels.
Having been an early LED adaptor and now slowing replacing old fixtures, newer LEDs provide much better quality of light, a couple of pointers.
For living area you generally want 2700k bulbs. 3000k for work areas. If you want to use dimmers looks for fixtures and bulbs that have a dim to warm feature (Phillips bulbs, Ovid pot lights). Standard LEDs when dimmed tend to turn slightly green tinge, makes peoples skin colour look unhealthy.
CRI 80 is not enough. Don't get anything under 90 for lighting in living areas.
If you have artwork that you need to light stick to halogen or spend the money on expensive LEDs (ie Soora).
Dimmers are always a pain, you most likely will have to replace some older dimmers. Even then there is a chance that it will not work. Sometimes adding in a single incandescent load onto a string makes the dimmer much happier.
Akos.
PS. Overseas manufactures lie about specs, stick to recognized brands. It took multiple tries to find decent LED strip lights.
If you have reading lamps and you value your eyesight and sleep cycles, you might want to be mindful that LEDs generate excess blue frequency light and are known to affect melatonin/cortisol sleep cycles and may lead to retinal damage (macular degeneration). Most LEDs, especially coupled with a dimming circuit, will produce detectable electrical transients that are not healthful. However, LEDs are likely to save you money on your energy bill and appease the energy conservation portion of the residential building code.
@kenneth Its the opposite, they typically produce less blue light as most output graphs will show the lowest output around 480nm which is incidentally not far off the peak of where blue light affects circadian rhythms.
@OP You need to decide on brightness and temperature. I prefer 3000K but its personal preference. 5000K typically only works in workshops, offices and bathrooms. 2700K is too dingy in my opinion. 800 lumens is 60W equivalent 1600 lumens is 100W equivalent. Expect a big price difference. 80CRI is sufficient for most people, if you really want you can buy a single 90+ CRI bulb and see if you can really tell the difference, i did that and the bulb now sits in its box unused, it wasn't worth the gas to return it.
You should go with name brand bulbs, Sylvania, Philips, Feit, Luminous produce good quality bulbs. Also enclosed fixtures are a problem as LEDs are heat phobic, if there is an opening to air your okay but if a fixture is fully enclosed then you need a bulb rated for it to get full life (Feit produces a number of enclosed fixture rated bulbs, which is stated on the package, but not all their bulbs are enclosed fixture rated).
Kenneth,
There may be a link between LEDs and a propensity for developing macular-degeneration - although how important that link is, isn't clear right now. There is no good evidence that "detectible electrical transients" produced by dimmers and LEDs "are not healthful".
Kenneth and Malcolm,
If anyone has a link to a scientific paper on this topic, please provide a link to it. The only paper I came up with is this one:
"Light-emitting-diode induced retinal damage and its wavelength dependency in vivo."
The study involved exposing rats to a different colored LEDs, including blue, green, and red LEDs.
I'm not sure that it's fair to conclude from this study that the effect seen in rats applies to humans exposed to white LEDs that contain a mix of colors.
The big concern seems to be the emphasis on blue light in many LEDs. (I've changed my computer screen setting just to be on the safe(r) side.)
Here is one study that might be helpful: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4734149/
Steve,
Thanks for the link. The authors concluded, "LEDs with an emission peak of around 470–480 nm should be preferred to LEDs that have an emission peak below 450 nm. Although we are convinced that exposure to blue light from LEDs in the range 470–480 nm for a short to medium period (days to a few weeks) should not significantly increase the risk of development of ocular pathologies, this conclusion cannot be generalized to a long-term exposure (months to years). Finally, we believe that additional studies on the safety of long-term exposure to low levels of blue light are needed to determine the effects of blue light on the eye."
Martin,
As far as I have followed this, the use of screens seems to be potentially more harmful than LED bulbs.
https://www.theguardian.com/society/2018/aug/09/blue-light-from-phone-screens-accelerates-blindness-study-finds
The back lighting technology on almost all phones & tablets (and newer liquid crystal TVs) are LEDs, some are just blue LED with phosphors. (10 years ago backlighing on laptops, TVs etc. was done with argon-mercury cold-cathode fluorescent technology, which also tended to be a bit heavier on the blue.)
So staring into your phone really more than just EQUIVALENT to staring into an LED luminaire, it IS staring into a LED luminaire. (Unless your phone, like mine has a paper label that says "Campbells" on it.. :-) )
But many phones today have a low blue light mode, and you can even install software in some cases (f lux) to reduce blue if you want to. Plus we have lived with the sun for our entire history and incandescent bulbs are something nobody scare mongers about...
Personally i think this is FUD mongering much like mercury in CFLs, cell phones causing cancer (almost after they were introduced but with no epidemic since massive uptake) and so forth. Its an excuse to prevent progress because legacy technology is familiar and comfortable.
Sunlight is great and all, but your pupils restrict when presented with that light, and you're looking away from it not toward it- the majority of the incident light hitting your retina is the spectrum of the reflected, light, not the full solar spectrum. And it wasn't available 24 hours of each day. Mammalian vision systems evolved in this spectral environment, and is fairly well adapted to it. Readily available lighting at near-daylight intensities for 24 hours per day is really only a century old, and has plenty of measurable effect on sleep patterns & general health, not all of it good. Thinking about the effects of spectrum is really just fine-tuning it.
The blue spectrum emissions of candles, oil lamps or wood fires is extremely small. Nobody stares directly at incandescent lights either, which (except for some halogens) have very little blue spectrum, mimicking the solar spectrum only at the red end of the scale. Taking in larger amounts of blue light really IS something new that came along with color CRTs, and cold-cathode & LED backlighting of LCDs.
Macular degeneration prevalence increases with age, and people in first-world countries are living about twice as long as the average from a century ago, at the dawn of widely available artificial lighting. Backlit phone screens that people would spend a lot of time looking at have only been around for a decade, not long enough to be able to do large cohort population studies to directly measure the risk factors (if any) on macular generation, since symptoms don't generally occur in the first 5-6 decades of life. Even large numbers of people staring at color CRTs or backlit LCD screens for many hours per day has only 3-4 decades of history. Has it moved the needle on macular generation prevalence? It's too early to tell.
Competent, peer-reviewed investigations into the direct biological effects of higher uptake of blue spectrum are worthwhile, even at the risk of the popular press going into full FUD mongering mode when interpreting the results. Screen backlighting is a very different issue from using LEDs (or other lighting technologies) to light up a room, and humans didn't evolve under either of those conditions. Adapting the technology to minimally interfere with our biology isn't a bad thing to consider.
Thanks for the tip on low-blue apps for phones! Whether it's a real risk or just a reasonable hypothesis based on initial investigation, for those who are already at risk for macular degeneration (or showing clear symptoms thereof) might consider adjusting their backlighting spectrum until more is known. (I know people in that boat who use smart phones frequently.)
People don't typically look at light bulbs either for long periods, though you are correct about screens being different, though TVs should be showing scenes which are not pure blue or white. Computer monitors used for business/internet browsing and phones doing the same would have a higher white proportion however.
Many monitors also are starting to come with low blue mode features and as i mentioned the software is available. I use F lux on the computer and its very good and has useful time setting features.
"Readily available lighting at near-daylight intensities for 24 hours per day is really only a century old, and has plenty of measurable effect on sleep patterns & general health, not all of it good."
No argument here, delayed sleep phase syndrome is hard to treat, though blue light blocking glasses and going camping work well
https://www.sciencealert.com/can-t-sleep-a-weekend-of-camping-can-help-reset-your-circadian-rhythm-study-suggests
"even at the risk of the popular press going into full FUD mongering mode when interpreting the results"
This is the problem, i support research for many of the reasons you mention but FUD mongering seems to influence policies over real science which is the real risk.
I forgot to mention in my last reply that the blue sky does much of the circadian rhythm setting so looking at the sun is not required and is highly not recommended.
You should buy the cheapest LED bulbs you can find that meet the following criteria (as necessary):
1.) Fixture size:
- most of your "normal" household bulbs will be A19
- small potlights maybe PAR 20, large potlights PAR 38, etc.
2.) Brightness (1500 lumens A19 is like a bright 100W incandescent bulb)
3.) "Color":
- 2700 K is considered "warm" light (normal in most houses)
- 5000 K is "cool" light like many traditional flourescent bulbs
4.) Are they dimmable?
5.) Are they rated for recessed fixtures (e.g. potlights)?
6.) Are they rated for damp locations?
7.) Are they rated for enclosed fixtures (e.g. typical ceiling fixture in most bathrooms)?
#7.) above is the tough one to figure out. Very seldom is it identified on the box. And the ding dong at the store will have no clue, the receptionist at the manufacturer will have no clue, and virtually no one else will have any clue either, lol. So you buy what's available, and just be aware it will burn out sooner than predicted because the computer circuitry in the base of the bulb will overheat. No fire issues, but it will overheat with respect to computer tolerances.
And never mind the stupid wattage rating you see on box in the store. That's completely irrelevant. You never know what power factor was used when they calculated the rating anyway. If they're LED, then the correct size, the lumens (brightness), and color is what you should be most concerned with. Those are always identified on the box.
And never mind all the talk about CRI. That's another specification you won't find on most boxes. Maybe if I'm going to pay $10-15 for a high end LED potlight, or if I was in charge of lighting up an art studio, I might pay attention to CRI, but other than that it's bullsh*t.
You should be able to find all the LED bulbs you need for less than $3 per bulb today. For a fixture that is used say 3 hours per day (using an average cost of $0.10/kwhr for electricity), the payback is less than 6 months compared to using a 100W incandescent bulb!
"above is the tough one to figure out. Very seldom is it identified on the box. And the ding dong at the store will have no clue, the receptionist at the manufacturer will have no clue, and virtually no one else will have any clue either, lol. So you buy what's available, and just be aware it will burn out sooner than predicted because the computer circuitry in the base of the bulb will overheat. No fire issues, but it will overheat with respect to computer tolerances."
Many will say not for enclosed fixture on the package or on the bulb, some say nothing and some say allowed in enclosed fixture. If it does not say it is rated for it then assume it is not and you will be right almost every time.
Feit has many that are rated for it and state that on the package.
I agree, FEIT is one of the few brands that shows it on the box (sometimes). In my experience most LED bulbs are NOT currently rated for enclosed fixtures. So I just buy according to my guide above, and replace as necessary.