Myths arise from incomplete knowledge; they can create seemingly possible answers that many people accept as fact.
There’s never a shortage of myths about new technologies. Even nearly a decade after the introduction of the LED light bulb, there are still misunderstandings about them which, for the most part, are based on faulty knowledge and hesitation to change.
Why LED lights are Better than Incandescent Bulbs
As you may already know, incandescent light bulbs make light by heating up a coiled tungsten wire filament in a vacuum inside a sealed glass bulb. The amount of power required to make the filament glow is rated in watts.
Since nearly 90% of the wattage used goes to heating up the filament, incandescent bulbs are pretty inefficient at making light. They get so hot, you can use one to bake a cake in an EasyBake. The filament ultimately breaks due to heat —after about 1,000 to 2,000 hours of use on average.
Light emitting diodes (LEDs) are semiconductors in a transparent epoxy casing. LEDs emit light through electroluminescence — that is, electrical current energizes electrons in the semiconductor material until the electrons emit a photon. Most of the electricity entering an LED is used to make light. It takes just 1.6 volts of DC current to light a single LED.
LEDS can also be built to emit specific colored light by using specific kinds of semiconductor materials to control the wavelength of the light it emits. For example, aluminum indium gallium phosphide (AlInGaP) is used as the semiconductor material for LEDs designed to emit light in wavelengths of 565 to 645 nanometers —or lime-green to red. White LED bulbs, however, rely on mix of colors and phosphor coatings to emit white light. This initially resulted in different manufacturers’ white light bulbs not looking exactly white.
It wasn’t until 2008 that an international manufacturer standard codified light output (in lumens) and color temperature (in degrees Kelvin or K°). This put the LED industry on track to produce light equal to or better in illumination. In essence, it got rid of the “weird colors” of LED. A standard indoor 60 watt lightbulb has a color temperature of 3,000°K and kicks out 800 lumens. An LED bulb now does the same.
LEDs Don’t Last Forever – They Last a Very Long Time
LED bulbs don’t heat up filaments, so there’s very little thermal stress. This gives them an extended lifespan. That said, it’s not true that they last forever. LED bulbs work by using what’s called a “driver” circuit. Basically, this is a small circuit board mounted below the LEDs on the bulb. It’s composed of a couple of diodes and a few other semiconductors that change the household 120 AC current into DC voltage.
While the LED’s themselves don’t get hot, the semiconductors on this circuit board can get a little warm. On cheaply made or defective LED bulbs, this board can actually get quite hot. When that happens, it’s a sure sign the board will burn out soon. However, for most bulbs with properly working boards, the actual LEDs will last thousands of hours and eventually dim.
It Doesn’t Matter What Price You Pay for LEDs – They’re All the Same
Like most everything else, when it comes to LEDs you get what you pay for. LED bulb prices have fallen to on par with standard quality incandescent bulbs. If you go with the average cost bulbs, you’ll be fine. If you dive for cheaper ones though, the board will likely get hot and the diode fail.
LED bulbs are Very Expensive
LEDs used to be expensive ten years ago, but LED prices have fallen. States like California have mandated the use of LED technology in their states, increasing demand and production.
Sure, incandescents bulbs are still dirt cheap — less than 40¢ for a 60 watt bulb with a 2,500 lifespan can cost 40 cents, but the real expense comes from using them. A 60 watt bulb will use 150,000 watts during its lifespan – that’s 150 kWh! At 10¢/kWH that adds up to $15 in electric costs. For the same 2,500 hours of light, a 9 watt LED bulb will use just 22500 watts or 22.5 kWh and tally up just $2.25 in electric costs (that’s $ 12.75 MORE than the traditional counterpart!).
For my money (and yours), the LED bulb is not expensive, and saves much more!
LEDs Contain Hazardous Chemicals
LED bulbs do not contain mercury, like CFLs or other fluorescents, that leak when the glass tube is broken. While a small quantity of phosphors used in LED bulbs may be used in the semiconductor material they are bound up and don’t leak.
All LED Bulbs Shine with a Very White (Awful) Light
We hear this one often. “I tried LED in the dining room, and it was TERRIBLE – SO WHITE!!” is recalled. The key to this myth is understanding that the problem wasn’t the LED, or the bulb, but that the wrong bulb was selected for the lighting task.
This important to note because LED bulbs can be tuned to have different color temperatures. The trick is knowing what the best temperatures are for what you want the light for and/or where you have the light. Basically, there are three magic number ranges to remember:
2,700 to 3,000 degrees Kelvin (K) —warm white or soft white. This is the same color temperature of tungsten incandescent bulbs.
3,500 to 41,000 degrees Kelvin — Cool white.
50,000 to 65,000 degrees Kelvin — Daylight. Tends to be bluish in comparison to the others. Think sunny, blue-sky day.
So, it’s not the LED bulb’s fault – the way not to make a lighting color, intensity or other mistake is to do your homework and make the right purchase selection.
LED Light is Too Blue
Nope. See above. The key is making the right selection.
Blue LEDs are Especially Dangerous to the Eyes
This deceptive myth is based partly on fact. This past summer, a University of Houston College of Optometry study found that over exposure to short wavelength of blue light disrupted the brain’s release of melatonin. For participants snuggled in bed staring at their phones, laptops or watching TV instead of getting drowsy and gradually drifting off to sleep, the blue light told their brains that it was time to get up. This continued exposure to blue light disrupted their circadian rhythms and caused sleep problems. When the researchers gave them blue-light blocking glasses to wear during their bedtime routine, their sleep disruption vanished.
The biggest source of blue light is the sun. But over exposure to blue light from computer and device screens has also been shown to increase eye strain and may contribute to macular degeneration. So, while daylight-calibrated LED lightbulbs might be bluish — the amount of blue light they contribute is probably insignificant compared to the amount of blue light coming off your laptop or device LED screen as you read this…quite possibly in bed, too, I imagine. Naughty.
With that in mind, consider getting yourself and your family members blue-blocking computer glasses. You’ll sleep better, focus better, and be much less likely for fall for other energy myths.
Source: Common LED Lighting Myths & Facts, December 29, 2017 by Vernon Trollinger, Direct Energy Live Brighter Blog.