Light Emitting Diodes, or LEDs, are both energy efficient and long lasting. They are available in many options, including Christmas tree lights, and seem to be taking the world by storm. What makes these lights different than older versions? What do terms such as lux, lumen, and kelvin mean? Let’s look at the magical world of the LED.

What are LED bulbs?

Information in this section is taken from Energy.gov and Interior Deluxe. Light emitting diodes (LEDs) are a type of solid-state lighting (SSL) -- semiconductors that convert electricity into light. Although once known mainly for indicator and traffic lights, LEDs are one of today's most energy-efficient and rapidly developing technologies. ENERGY STAR-qualified LEDs use only 20%–25% of the energy and last 15 to 25 times longer than the traditional incandescent bulbs they replace. LEDs use 25%–30% of the energy and last 8 to 25 times longer than halogen incandescents. Basically, LEDs are just tiny light bulbs that fit easily into an electrical circuit. But unlike ordinary incandescent bulbs, they don’t have a filament that will burn out, and they don’t get hot. It is expected that LEDs will completely replace incandescent and halogen bulbs sometime in the future.  Their light output is measured in lumens instead of watts. Because of their durability and performance these bulbs work well in both indoor and outdoor environments. To fully understand LEDs, and to better figure out which lights best fit your needs, it’s also important to understand watts, lumens, lux, and kelvin.

Watts, Lumens, and Lux

Interior Deluxe, using information from the US Department of Energy, has an easy to use calculator to compare watts to lumen. It also provides definitions for what watts and lumen mean. Watts measure the amount of electrical power used to light a bulb. This means that the more watts a bulb shows the more power it will consume to produce light. So, a 200-watt bulb will use more power than a 100-watt bulb, giving just a little bit better and brighter light. These bulbs use only 10% of the electrical power to produce light while wasting the remaining 90% in producing heat. So essentially bulbs that give a watt reading are just letting the consumer know how much electrical power it will consume. The brightness of light or the output is up to the consumer to determine once they plug that bulb in the socket. In contrast to watts, lumen is a measurement of light that is more appropriate for consumers. Lumens measure the output of light. In other words, lumens tell us how bright the light produced by a bulb will be. A few examples include a 40-watt incandescent bulb equals around 450 lumens, a 60-watt incandescent bulb equals around 800 lumens, and a 100-watt incandescent bulb equals around 1600 lumens. Hunker provides an easy to understand explanation of the relationship of lux and lumen. Lux is a measure of how many lumens are present in a given area. To illustrate the difference between lumens and lux: While the sun always produces the same number of lumens, on cloudy days there are fewer lux outdoors. At night, only the lumens provided by the moon and stars reach the ground, leading to extremely low lux under a night sky. To achieve a desired lux level in a given space it may be necessary to use many light bulbs, each producing a given number of lumens.

Kelvin

Apart from brightness, you also must consider the color of the bulbs. This is typically denoted by a Kelvin rating (usually 2,700 to 6,500) and accompanied by a descriptive name, such as soft white or daylight. The following ranges are taken from a CNET article on warm light bulbs versus cool light bulbs. Soft white (2,700 to 3,000 Kelvin) is warm and yellow, the typical color range you get from incandescent bulbs. This light gives a warm and cozy feeling and is often best for living rooms, dens and bedrooms. Warm white (3,000 to 4,000 Kelvin) is a more yellowish-white. These bulbs are best suited for kitchens and bathrooms.  This OttLite Cobra Color Changing LED Lamp is a color changing LED desk lamp offering 3 levels of lighting, from warm light to cool light to natural daylight (3,000K, 4,000K and 5,000K.) Just select the color that is best for your needs. Bright white (4,000 to 5,000 Kelvin) is between white and blue tones. With a less cozy and more energetic feel, bulbs with this color range are best for workspaces (such as a home office or garage) and kitchens with chrome fixtures. The OttLite Cobra Color Changing LED Lamp mentioned under “warm white,” transitions between warm white and bright white lights. Daylight (5,000 to 6,500 Kelvin) has a more bluish tone. This light color will maximize contrast for colors, making it ideal for working, reading or applying makeup. An example of a task light falling into this category is the Uno LED Flex Desk Lamp. It has 28 high performance LED bulbs, 4 different brightness levels, and a flexible arm allowing for optimal positioning. Another option to consider is the Z-Line Lamp by Enfren BLACK. This modern-looking desk lamp offers brilliant white LED lighting with glare-control filters that help reduce eye strain. It reproduces natural light and prevents flickering. While lights with a bluer hue make it easier to see contrast and small detail it’s also important to consider the health pros and cons. The main source of blue light is the sun and it’s the light that helps the body manufacture adequate amounts of vitamin D. Moderation is the key though as too much blue light can potentially increase your risk of macular degeneration as you age, as well as, cause eye strain. Blue light absorption rates are especially important after cataract surgery. Conversely, blue light can also increase alertness, help with memory and cognitive function, and can even elevate your mood.  If you’re worried about too much blue light exposure through your electronic devices using things such as computer glasses (they come in both prescription and non-prescription) or screen protectors (such as these Reticare screen protectors) can help.  To learn more about blue light, including scientific definitions, see All About Vision. With that in mind, when choosing light bulbs for a room, think of what you normally do in that space and buy bulbs for that purpose. To find more products and ideas to make your life easier check out our full site at https://www.independentliving.com/.