The Ultimate Guide to LED Light Bulbs

A Background to the LED Light Bulb Revolution

Here in the United States, 2012 through 2014 were the years of new light bulb requirements that effectively banned the most common household (and many office) light bulbs. These included 40 watt to 100 watt general use incandescent bulbs used in many lamp and ceiling fixtures.

This effective ban came from 2007 legislation signed by then-president George W. Bush, which required that light bulbs produce a minimum amount of light (or "lumens") for every watt of energy used. This was done to keep us from wasting energy where we didn't need to, as energy production has an environmental impact and other ramifications.

Since traditional incandescent bulbs produce relatively few lumens per watt, they didn't meet these new requirements. Most of the energy they use produces heat, and only about 5 to 10% of it produces light. This means that they're inherently inefficient and cost more money to produce light than other options do.

Despite the legislation, it's still legal to purchase and use these bulbs, but they can no longer be manufactured in the United States or imported into the country. So buying them means finding whatever inventory still exists.

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Replacing Incandescent Light Bulbs

We've talked in other posts about your options for replacing general lighting incandescent bulbs, including what to look for on lighting packages. Past articles include "Replacing Your Incandescent Light Bulbs" and "Missing Your Incandescents? Try Rough Service Bulbs." You can check out those articles for some additional information. But here's a rundown of your primary options:
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HALOGEN LIGHT BULBS
Halogen bulbs are a kind of incandescent bulb, using halogen gases and higher pressures inside the bulb to burn more efficiently. This efficiency kept them from being banned by legislation. They glow a little whiter than traditional incandescents, but are overall quite similar while saving around 30% on energy.
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COMPACT FLUORESCENT LIGHTS, or CFLs
Often recognized for their "swirl" or spiral design, these became an early energy-saving alternative to incandescent bulbs, operating on about 25% of the power to produce a similar amount of light as incandescents. They could also last for years. However, they didn't work well in the cold; most didn't dim; most took a while to reach full brightness; and many people didn't care for the light they produced. Plus, their lifespan was reduced when used in places where they were turned on and off frequently.
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LIGHT EMITTING DIODES, or LEDS
The topic of this article, LEDs offer many of the benefits of incandescent bulbs, yet they're the most efficient of any general lighting option. They also offer a wider variety of color temperatures and are even available as smart bulbs that can be programmed, provide almost any color, and more. We'll explore these in depth.
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What Does LED Stand For? 

When it comes to light bulbs, LED stands for "Light Emitting Diode." The next section explains what we mean by a diode that emits light.

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​What are LED Lights?

Technically, an LED is a semiconductor device with P type materials (with Positively charged carriers called holes) and N type materials (with Negatively charged carriers called electrons) that are brought together to form a diode. When powered by electricity, the holes and electrons move toward one another; in order to combine, the electrons must release photons, which we experience as light.

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LED Basic Features

LEDs have fast become a popular lighting option because they boast many of the same qualities as incandescent bulbs while lasting far longer and using about 1/6 the energy to produce the same amount of light. Here are their most important basic features:

• Long life: while some cheaper LEDs are "only" rated to last about 5000 hours, many are rated for 25,000 hours. Compare this to a typical 1000 hour rated life of incandescents.
  
  
• Energy savings: today's LEDs can produce equal lighting to an incandescent with about 1/6 the energy. Most 60 watt replacements only use around 10 watts.
  
  
• Instant on: LED lights come to full brightness as soon as you turn them on.
  
  
• Frequent on/off: LEDs have no problem with frequent on/off cycles -- something that dramatically shortened the lifespan of CFLs.
  
  
• Mostly dimmable: some LEDs are not dimmable, and these are often less expensive than dimmable LEDs. This is a good way to save a few bucks in places where you don't need dimming capabilities. (Non-dimming LEDs, however, may not handle common changes in line voltage as well as dimming LEDs, so consider this when purchasing.)
  
  Most LEDs do dim, though they need to be compatible with the dimmer you're using. If your dimmable LEDs don't dim properly on your dimmer, you may need to get a new dimmer. In some cases, for instance, dimmers have a minimum load on them, and because of their low wattage, even several LEDs may not provide this load. In this example, you would need a dimmer with a low load minimum.
  
  In any case, make sure to check the lighting label before buying if you need an LED bulb to dim!
  
  
• Really "rough service": we all know you have to handle incandescent bulbs carefully, not only because of the glass bulb but also because of the delicate filament. Once that breaks, the bulb will no longer produce light. For this reason, some incandescents are made with better supported filaments to help them withstand vibration; these are known as "rough service" bulbs. But in the case of LEDs, you have no filament and typically have plastic bulbs, so a quality LED is really built to last!
  
  
• Useful in cold temperatures: like incandescent bulbs, LEDs have no problem operating in cold temperatures. CFLs don't fare as well in cold weather.
  
  
• Mercury free. CFLs infamously contain a small amount of mercury, which requires special clean up if they're broken. LEDs have no mercury in them. And they're likely to cause less overall waste compared with other light bulbs not only because they can be recycled but because they'll so seldom be replaced at all.
  
  
• Cool to the touch: ever try to touch an incandescent bulb while it's operating? We hope not! But LEDs are cool to the touch ... at least on the bulb portion. This also means they release almost no heat (or UV rays). They still wick a lot of heat toward the base, though, so keep your fingers clear of the base until it's cooled down.
  
  
• Range of color temperatures: replacements for incandescents do a good job of mimicking the "warm" look of the older bulb (and can even mimic its warmth with dimming -- see "Warmer Dimming" below). But LEDs can also come in cooler white and daylight color temperatures, giving you choices for a wide variety of settings and preferences. (See more under "Lumens and Color Temperature" below.)
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• Good color rendering: LEDs do a good job of representing the true colors of an object, with some bulbs more specifically designed for premium color rendering. Get more details on this below.

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LED Advanced Features

While LEDs offer a lot of benefits as replacement lighting, their digital nature also lets them offer other features along with lighting. Here are a few of the ways people are enhancing light bulbs by adding to LED technology:

• LiFi: this looks like a big future for light bulbs. Rather than using radio waves to transmit data, as WiFi does, LEDs are able to use light waves to transmit data. They do so by blinking at such a high speed you cannot detect the change in lighting with your eye. LiFi can move data far faster than WiFi can.
  
  
• Voice Commands: yes, your light bulbs could listen in on you. While some people have privacy concerns about this and other elements of the "Internet of Things" (connected "smart" objects in your home), light bulbs are used in every room of your house and can be used to detect your commands. Connected with other items in your home, they could transmit your commands to control not only lighting, but also temperature, home security features, and more.
  
  
• Speakers: several brands have incorporated speakers into their LED bulbs. Placing these in several rooms means you can move about your home and continue listening to your favorite songs. And if your bulbs respond to voice commands, you can change what you're listening to on the fly.
  
  
• Cameras: for home security, some bulbs come with cameras built in, as well as motion detection, to record anything moving in sight of the bulb. They can also alert you through your phone when something's detected.
  
  
• Programs: many of today's bulbs can be programmed to turn on and off at certain times; to gradually dim as you're going to sleep and to gradually brighten as you wake up; to blink with an incoming text message to your phone; to respond to the beat of music; and much more. Many are connected to your network through your WiFi (which brings up questions of security); others only respond to your phone via Bluetooth.
  
  
• Colors: many of these bulbs also offer colors besides white, so you can set them for any mood. Some offer a handful of colors on a dedicated remote while others offer millions of colors controlled by your phone. One use for color control: using warmer whites leading up to bedtime and cooler whites when you want to be alert, based on how these colors affect the brain.

As you might imagine, this is just the beginning for smart bulbs. With light bulbs in every room of a house, they have the ability to keep us connected to any smart system we're using.

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Lumens and Color Temperature

If you watched the video above about replacing incandescent light bulbs, you may have already picked up on the key points of choosing an LED light bulb for your home or office. Instead of looking at watts (how most of us chose general use light bulbs in the past), you need to see how much light is produced. This is measured in lumens. A 60-watt incandescent bulb, for instance, produces about 800 lumens. An LED bulb may produce the same amount for around 10 watts. You can see this in the image below.

The other thing to look for is "Color Temperature," which may read as "Light Appearance," "Light Color," or something similar on a lighting label. This is measured in Kelvins, so you'll see a number followed by a K. Incandescent bulbs have a color temperature of around 2700K, which is a warm look with a hint of yellow. 2700K to 3000K are often referred to as "warm white."

Higher numbers look cooler, appearing more white in the range of 3500K to 4100 (known as "cool white"), and even slightly blue in the range of 5000K to 6500K (​known as "daylight.")

When replacing incandescents with LEDs, you may want to stick with 2700K LED bulbs for a similar look to what you have, though some people prefer the bluer light of high Kelvin bulbs. Some will mix it up, with 2700K bulbs in many areas of the home but higher Kelvin bulbs in kitchens and utility areas. This is a matter of personal preference.

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LEDs and Warmer Dimming

Many people seem to love how "warm" incandescent bulbs appear. As we explained above, this warmth comes from a color temperature of about 2700K, which LED bulbs have come to mimic really well. But incandescents have another trick up their sleeve: when you dim them, they become even warmer in appearance, decreasing to around 2200K.

New LED technologies have now begun mimicking this feature as well, as you can see in this Philips "warm glow" LED below. While Philips uses the term "warm glow," other companies offer a similar feature under different names.

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LEDs and Color Rendering

Different lighting technologies produce different balances of wavelengths on the color spectrum. This allows us to see the colors of objects more accurately or less accurately under various lights. For instance, as you can see from the image below, sunlight provides us with a strong balance of all wavelengths, letting us correctly see all visible colors.

The ability for light bulbs to render colors well has traditionally been measured as "CRI" from the Color Rendering Index. On this scale, incandescent and halogen bulbs are typically considered near perfect in their rendering, scoring 95 to 100 out of 100. But as you can see in this image, their light weighs heavy on oranges and reds while not providing as much emphasis on green and blue wavelengths.

Meanwhile, LEDs are typically rated around 80 CRI (though certain LEDs score in the 90s). But you can see from the chart that, while they don't emphasize oranges and reds as well as incandescent bulbs, they do emphasize some green and blue wavelengths better than incandescent bulbs.

So while the Color Rendering Index makes it seem like LEDs don't render colors as well, the truth is that LEDs render colors differently, so the best technology comes down to preference and/or what you're trying to light. This is why lighting experts are now looking into a new index that will better take into account a variety of lighting factors.

You can see this difference firsthand from the images in our article on this topic.

Suffice it to say that LEDs do provide us light across a wide range of wavelengths and do a very good job at rendering colors, even if they do so a little differently than incandescent bulbs.

From "Popular Mechanics"

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LED Lights and Quality

From Energy Star

While once out of financial reach for the average consumer, LED light bulbs have become so affordable that their energy savings (compared to incandescent bulbs) often cover their initial cost within a year. Yet for those who love a bargain, it's tempting to buy bulbs that are below the pricing for trusted brands.

These bargains, however, aren't always a good value, because these low prices are often achieved by using cheap components. While the diodes in an LED might keep working, the driver in a bulb might die early, ending the life of the bulb; odds of this happening are higher with low-end components. Cheaply made LEDs are also more likely to flicker or buzz.

For one clue to the quality of a bulb, consumers can look to its rated life. Some are only rated for 5000 or 10,000 hours, while others may be rated for 25,000+.

​Another clue is the warranty. Low-end bulbs may have warranties of 3 years or less while some manufacturers warranty their LEDs for 5 years or more.

This still means a cheap bulb could last for a few years, but not for anywhere as long as the other, so over time you might actually spend more on the cheap bulbs than you would on the more trusted bulbs. And you might have a worse experience with them along the way.

What's more, Energy Star has found that the quality of certain bulbs diminishes quickly, as you can see from this image. Because of this, consumers can look for bulbs with an Energy Star certification when looking for an LED whose quality and brightness are expected to last. (Note that LEDs with an Energy Star rating cannot claim longevity of more than 25,000 hours, even though standard testing might normally rate them with a longer life.)

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What Lighting Specialists Tell Us

As LEDs transform the world of lighting, we thought we'd see what experts in several lighting niches could tell us about the impact of LEDs. Here's what we found out:

Daniel Stern, editor of vehicle lighting industry technical journal DrivingVisionNews, spoke about LEDs and automobiles, explaining some of the ways LEDs are making driving safer. "LED brake lights eliminate bulb burnouts and light instantly at full intensity -- a quarter of a second faster than filament lamps -- letting following drivers react 22 feet sooner at 60 mph and preventing crashes."

​On the other end of the car, he points out: "Yesterday's low and high beams are being supplanted, so far mostly in Europe but probably soon in America, too, by LED-matrix Adaptive Driving Beams: full-time high beams that dynamically shadow out other road users in real time for high-beam seeing performance with low-beam glare levels. Tests in Germany show ADB gives a driver nearly 100 feet more seeing distance than low beams, without more glare."

Despite the theoretical benefits, Stern cautions buyers about replacing incandescent car bulbs with LEDs without guidance or study: "There's a mountain of unsafe automotive LEDs on the market, all promoted as 'upgrades.' A few legitimate ones are now available from Philips and Sylvania, but they don't necessarily work safely in any/every application for a given bulb type. The consequences of a bad choice are much worse in the safety lights of a car than they are over the kitchen table in the house."

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In our social media posts, we sometimes reference articles about the impact of light on health. We heard from Ken Ceder on this topic. Ken is Executive Director of "Science of Light," a non-profit organization focused on biologically beneficial light and bringing this into classrooms. Ken told us, "The transformative benefit of LED lighting in the field of biologically beneficial light has been the ability to engineer a more finely tuned, controlled light spectrum compared to our old fluorescent technology." He adds to this that LEDs have "​transformed the size of light therapy devices from 1' x 2' light boxes to tiny hand held devices weighing mere ounces."

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​Finally, we spoke with professional photograph Neil van Niekerk who shared several ways LEDs are changing his work: "​When shooting video clips or interviews on video, LED light panels have become my go-to light source. Obviously flash wouldn't work here -- we need continuous light. What makes LED lighting really attractive over other continuous light sources is that you can change the white balance to match the existing available light. This way you can more seamlessly blend the additional light and the ambient light."

He also finds that continuous LED lighting with its adjustable white balance has other advantages over flash photography. For one thing, it keeps from startling babies during newborn portrait sessions. But in a larger sense, it provides a "what you see is what you get" advantage over flash photography. "For dramatic portraits with weddings," said Neil, "I've been using LED lights for a while now. For me, LED lights are faster to use and adjust than flash would be. Very helpful when time is limited."

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Replacing Lights with LEDs in the Workplace

When we talk about replacing light bulbs with LED lights, we might picture household style bulbs -- the types we put in bedside lamps or in recessed ceiling cans. While these all have LED replacements, there are also LED replacements for fluorescent tubes and multi-tube panels, for large high bay lights used in warehouses, for street lights, for outdoor wallpack lighting, and more.

For instance, "Corn Cob" LEDs are used to replace HID bulbs like metal halide lamps and LED T8 bulbs are able to replace fluorescent tubes. You can check out one of our articles for information on replacing fluorescent troffers with LEDs.

Regardless of where you replace older lighting technologies with LED technology, though, you can enjoy the benefits of LEDs like longer lifespans, lower energy costs, and quality color rendering. There's plenty of reason to consider upgrading to LEDs at this time, and when you're ready to do so, Lighting Supply is here to help!

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