LED Lighting vs. Tungsten Lighting: What’s Best for Your Operation

Nearly all of the responses to differences between LED vs tungsten lighting are focused on issues of life, efficiency, energy use, etc but ignore a very important characteristic of the light spectral energy distribution curves which are quite different in nature.

A tungsten light bulb has an energy distribution output that is referred to as a black body radiation source not unlike the sun or a star. Most of the energy produced is in the infrared part of the spectrum and accordingly more of its output doesn't produce useful light in our eyes' retinal sensitivity portion of the spectrum, basically between 400-700 nanometers of light. The tungsten source, accordingly, could be thought of as a heat source which produces a small amount of light for our eyes to use. It also is the reason that it appears reddish to yellowish compared to noon day sunlight, also known as D6500 Degrees K.(CIE)

LEDs can have a widely different designed energy distribution output and (since the first Light Emitting Diodes were produced back in the 1950s) have evolved from sources in the IR range to red, green and later blue. By customizing the doping of these semiconductors, engineers are now able to economically create light that simulates conditions that "appear" to be everything from warm (2800-3200 degrees K) to Bright White and Daylight (5000-6500 degree K). Although they can be "blended" to shape the visible light curves, they do not really appear exactly light a black body radiator even in the visible (to human eyes) part of the light energy spectrum. These variations in the shape of the LED light curves account for the ability to sharply cutoff energy output in the UV and IR areas. But also they create a problem when comparing colors of illuminated objects that may appear the same in one lighting condition but quite different in another. This phenonomen is known to color scientists as color metamerism or a conditional color match. It has caused much frustration when people try to match colors with either different lights, having their own unmatched energy distribution curves, to the dyes or colorants of visible objects that have their own energy absorption and reflectance curves. The latest home lighting attempts to be agnostic so that the user can choose the "mood" or apparent color temperature they like best for any room, but remember that none of the choices is truly a black body radiator even in the human visible portion of the very wide electromagnetic spectrum.

We have come a long way since Texas Instruments invented the LED and its first use was as an opto-isolators in signaling circuits. Today's TV remote controls use IR LEDs, similar to the ones first used before pioneering engineers figured out how to make them into useful lighting sources that could revolutionize indoor lighting in way not dreamt of back when man harvested fire to see at night. Hopefully engineers younger than myself will continue the perfection of EM energy uses not yet invented but important to the future of society.

Probably want to consider the cost to the power utilities as well....

https://www.researchgate.net/publication/297707819_Power_Quality_Effect_of_Using_Incandescent_Fluorescent_CFL_and_LED_Lamps_on_Utility_Grid

That's an awfully short summary to have a conclusion! Among other things, there was no mention of spectra/color temperature.

I've noticed that many people are so accustomed to the color of incandescent lights that they prefer the "warm" color temperatures. I personally have a strong preference for the whiter colors more like daylight that are now available with LED lighting

I suspect that when incandescent lamps first became available, the fact that they were closer to white than candles are, made incandescent lamps glaring to many people.

Gravity can do no work unless something falls closer to the center of the Earth (or other massive body), and it takes work (energy) to produce any form of light.

If you have seen, or are trying to produce, a "Gravity Bulb", it's clearly a SCAM!

There was no mention made of the longevity of the LED lights. We had two chandeliers with fancy flame shaped LED bulbs to make a display. Both units used 6 led bulbs each.

More than half of the bulbs failed within the first 6 months and some failed alarmingly turning into short circuits of low enough value to trip the circuit breaker. So we now have a less fancy set of bulbs like candles so we will see how they go. No luck with the supplier for the fine print excludes the bulbs from the warranty.

LEDs in strings also suffer from the failure of one taking out the rest in the series. Despite all the hype they are less reliable than the 10000 hours or whatever exaggerations the makes deem to embellish the packaging. One failed diode rendered a section of the stoplight bar on a car I was asked to fix non compliant.

Has anyone else noted that where once the internal configuration of a LED was such that the cathode and anode were easy to recognise, forget the different length leads or the flat on one side, doesn't exist often any more so the only way to tell the polarity is to use a diode check on a meter.

Of course you can get constant current polarity independent LEDs and I use them for certain taske.

A tungsten lamp doesn't give a damn about polarity or ac/dc it just glows and keeps you warm and bright and they can also be used as a ballast load to soak up overvoltage spikes. LEDs still have a way to go for reliability even in the fluorescent tube replacements.

I've not had problems with LEDs other than availability of styles to replace incandescent or fluorescent.

Used to manufacture with them, tens of thousands per day making auto lighting for signalling and interior. Reliability was almost always beyond the LED manufacturer's claims. I remember one test set that we were required to operate/test by the auto company. The test concluded 7 years after last vehicle in that model was sold. 15 years cycling on and off, sometimes at 140% overvoltage, sometimes at 80DegC, sometimes at -40DegC, sometimes at 95% humidity.

I'm not saying that end product suppliers might not shortcut and supply inferior assemblies, just that I haven't experienced that in the consumer products that I've got so far.

LED strings in stoplights or any other item will have the failure mode you described, but at least the owner had some functionality (compared to a Tungsten filament) after the failure.

For polarity determination, it depends on the component package. Round ones usually have a "flat" formed on the collar of the LED capsule to denote polarity while rectangular SMT devices usually have a chamfer on one corner of the package for polarity.

One place I worked a while ago replaced 50% of the lamps in a building with LED (One side of the building) and at 6 months, the staff in the building could not remember which was the LED set. Basically it made no difference because the correct colour temperature had been selected.

We were monitoring power usage in that facility and the step drop over the weekend the exchange was made was sustained and the payback was justified, even without consideration for reduced maintenance and replacements.

Not saying that I haven't heard of poor experiences with LED introduction, but so far, so good here.

More than 50% failures in 6 months means for sure that you used cheap (most probably Chinese) brands. I'm using LED bulbs in my house since several years and I had no failure so far - but I use only Philips and Samsung bulbs. I also have an LED lamp, which has 8x3 LED's - no failure either.

Even if "known" brands are more expensive, their reliability compensate the price for sure. And they also have a more "accurate" color (I prefer "warm-white") than the cheap brands.

Note that a short-circuit type failure is not related to the LED itself but to its DC power supply - probably using cheap components (the miniature electrolytic capacitors are often the cause).

Then I can assume that new car manufacture use cheap LED's because I see a lot of newer automobiles with burned out LED headlight adornments.

oilcan13

I was talking about LED bulbs used at home. However, the reliability should also be high for the cars' LED headlights. The question is how many of those headlights were originally fitted (from the cars manufacturer's factory) and how many were "added" by the car users, who (obviously) might have used cheap versions - LED headlights are still quite expensive).

No the LED bulbs used were not cheap Chinese LED brands but well known brands, in the arm and leg price range. The bulbs consists of strings of leds made to resemble old style filaments.

As for cheap LEDs any country can turn out cheap products and do. It just depends on the QC department to the quality of the product. As for the cars with the failed LEDs no they are not aftermarket light I have seen but OEM products. The dealer wanted $400 to replace the LED bar which for a 20c item.

If it is a 20¢ item on the bar, then fix it! There is a good chance that the problem is a poor solder connection. Reheat each point with some new flux core solder, and see if it works.

i have yet to have an LED bulb - or any of their diodes - fail, and am in my third all-LED residence. as for automobiles, i believe that the lamp manufacturers provide more LEDs than required for statutory brightness, so the loss of a few LEDs in a lamp does not render it noncompliant.

There is virtually no information in this article. It just states that power consumption is different and gives generalities. No mention of where tungsten might be better, even though that was in the conclusion. Data on power consumption and life-cycle costs would be good.

GA! You just provided a whole lot more information than the OP!

...and I totally agree with your final assessment. My home is not quite totally LED; the attic, the crawl space, and the oven still have incandescent lamps.

It's a very short post. Not much information to draw any conclusion!

The primary requirement of light is visibility, i.e. replacement of Sun, in general view, so colour temperature, frequency of flicker are points to work on.

Of course, power consumption is a very important point too along with longevity.

Purpose of the light can differ the requirement of colour and clarity of illumination.

1. Indoor or Outdoor

2. General illumination or Security purpose

3. Mood of the environment.

4. Indoor Photosynthesis purpose illumination etc.

These are few I could thought off, there may many more.

Though now LEDs are replacing most of the incandescents, still in some places incandescents are still relevant ....

So I have an outside Sodium light in my yard. Lights all the time, regardless of the weather. My two neighbors both have LEDs attached to their houses. They only light when outside temp is above 35-40F. Around 30 or so, they "kind of flicker"i.e. on-off-on-off. Down around 15F, neither of theirs light at all. (and we all leave them on all the time)

Also noticed during cold nights, fluorescent fixtures in unheated garage don't work nearly as well as the incandescent did

..."Truth is, LEDs actually thrive in cold temperatures. Owing to the fact that LEDs are semiconductor light sources that produce light when an electric current flows through them, they remain unaffected of cold ambient temperatures and are able to turn on instantly."...Nov 4, 2019

https://www.hyperikon.com/blog/led-performance-in-cold-hot-temperatures/

Reinforcing SE's post #22; The lights in my refrigerator are all LEDs, both in the main section and in the freezer section. Those in the freezer section have experienced temperatures well below freezing continuously for the last 5 years, at least, and they come on instantly.

From your description, I'm guessing that your neighbors have CFLs, not LEDs, in those lights.

I still have one pair of 4' fluorescent tubes in my shop, and a couple of 4' LED tube pairs. Just a couple of days ago, it was cold enough that the fluorescents failed to come on, but the LEDs were just fine.

Guessing it's possible neither neighbor really knows what they have. I can't see them as there enclosed in globes.

Quite possible!

You clearly live in a colder environment than I do. I've lived in the same house for 50 years, and the coldest I've ever seen here was 16°F, so my experiences may not entirely apply in your location.

Most of my outdoor lighting is controlled by photosensors and motion sensors, so they are not wasting energy during the day, and only come on when there is something warm moving. A cat will trigger them. Before 120V LED lamps became affordable, I used CFLs in those fixtures, and they would fail to illuminate when it was cold. I'm not aware of any problems since I switched to LED lamps.

Since both of your neighbors apparently have the same problem, and you say their lamps are both enclosed in globes, I suspect they both use the same technology. There is a small but real possibility that shrinkage due to cold is causing some metal parts to lose contact.

Finally, if those neighbor's lamps have been installed for more than around five years, they should be replaced. The quality of the driver circuitry that makes LED lamps work on 120V has improved greatly. Several of the LED lamps I bought 6 or more years ago have failed in one way or another; none of the more recent ones has failed. ...and of course the prices have come down dramatically!

I have been making the switch when older lamps burn out. My take on this is LED is much better all-around unless you need a warmer lighting environment as in food displays or photography.

I have several LED fixtures in the warm range for night and mood lighting...Here's a two bulb light with warm on the bottom and cool on the top...spreads non-glaring light throughout the room...

Hard to get an accurate exposure here, the bottom light is more intense then it appears...and the top less intense...

Quite an artistic lamp. The apparent differences in intensity probably are due, at least in part, to the characteristics of the camera sensor and software.

Yes, here's one with just the bottom warm light on....

Still not an accurate representation....this is enough to illuminate the entire room in a soft glow....

https://www.kptv.com/news/pair-of-local-companies-aim-to-create-uv-light-system-that-kills-coronavirus/article_754bdbec-8942-11ea-ab82-e3fd68d415c8.html

https://www.nhl.com/news/lars-eller-donating-uv-light-sanitizing-technology-to-homeless-shelter/c-316994550

Happy to see this technology being donated to homeless shelter.. MRSA infections in hospitals and jails are for the most part attributable to the homeless population...

We need to use care when we say "attributable to the homeless population." This can imply an intent or behavior as the cause, instead of seeing the environment as the cause. I assume you intend the reference to be the environment. Are there statistics that show a correlation between homelessness and MRSA, and if so, is the correlation direct or indirect?

--JMM

I would attribute this mostly to lack of cleanliness, such as bathing, washing clothes, sleeping on clean bedding and lack of medical attention...also contributing factors such as close habitation and activity, such as gyms and jails, also I think in large part due to close contact and cohabitation as contributing factors...also high traffic areas where person to person contact is high...these contributing factors are not exclusive to the homeless, just prevalent....

https://pubmed.ncbi.nlm.nih.gov/31493182/

While LED's offer power saving advantages, the lack of color discrimination is important. Ever try reading the color code of resistors under LED lights? LED flashlights have similar drawbacks as the beam width is narrow. In addition the glare caused by the intense light makes reading fine print difficult.

While they have their uses, tungsten will never go away.

There is an option of warm light in LED you can change it. which supports you from blue eye syndrome. for indoor led lighting and outdoor led lighting check www.Highlineled.com

I have read the color codes of hundreds of 1/4 Watt resistors under LED illumination, with no more uncertainty than I used to have with tungsten lighting. I've read the codes on several dozen just his past week. The only tungsten lamps left in my house are in the ovens and the crawl space. I still have a couple of CFLs in one outdoor fixture; everything else is LED. I do commonly use a loupe these days, but that's because of my age, not because of the light source.

The better LED flashlights have either variable or multiple beam widths.

The one advantage left for tungsten lamps, in my view, is their ability to withstand heat, as in an oven.