What, in the world, is a lumen? And, with LED lighting: how many lumens is enough? All your questions, answered, right here.
Isn’t wattage the important thing? Not anymore!
Before LED lighting, the brightness of a light was measured by its wattage output. Then, LED changed the game. LEDs use less power to create the same amount of brightness.
Wattage is a measurement of power expenditure – not brightness. Incandescent bulbs work from a uniform standard of power usage. LED lights do not.
Why LEDs are Great
A Light Emitting Diode, or LED, is a group of three individual diodes that produce red, blue, and green light photons. Put a bunch of these little diodes together, and you have an LED lighting unit. By controlling the three diodes duty cycles, LEDs can produce many colors.
Traditional light bulbs produce heat in order to create light. Incandescent lights create brightness by heating a coil or filament. The light, emitted by heat, is called incandescence.
LEDs do not emit heat, so their brightness can’t be quantified in incandescence. Instead, LEDs produce light through cold radiation, called luminescence. Even, running full blast, LEDs are cool to the touch.
The luminescence of LEDs can be customized without adjusting the bulbs wattage. That means you get more light, for less money.
Incandescent lighting produces enough heat that they alter a room’s temperature when lit. Green lighting with LEDs will help you save on electricity from your lights and your air conditioner.
Buildings with thousands of individual lights are behooved to look into why you should invest in LED lights for your business.
LED lighting is the reason why the brightness of a light can no longer be expressed in wattage. LEDs create light differently than all other lighting sources.
In 2011, the Federal Trade Commission required the measuring of light bulb brightness output to express lumens – not wattage.
So, here is the lowdown, on how many lumens you need…
How Many Lumens do I Need?
The first thing you need is some context to understand how bright a lumen is. Too much light can be as detrimental to your aims as too little. So, deciding how many lumens is enough depends on what’s being lit.
How Bright is a Lumen?
On a clear and sunny day, the sun’s brightness is over 7.5 million lumens. If you fit that many lumens into a ceiling light, everyone in the room would go very blind.
The amount of light disbursement makes a big difference in how many lumens you want. The sun’s millions of lumens don’t blind us, because we are far away. And, because you don’t look directly at the sun – or else you go blind.
Take care when it comes to lighting your office, building, or home. The closer to the light source, the more important luminescence is. When it comes to man-made lighting…
The brightness of an HID car headlight is 3,000 lumens. Those are the really bright headlights, that seem like high beams from oncoming traffic. Obviously, that is too bright for standard room lighting, as well.
Standard 60 watt living room light bulbs produce 800 lumens. Overhead T5 tubes produce around 1,200 lumens. Candles give off about 12 lumens, depending on the candles size.
If you use candles to light your space, you will save lots of money on electricity, but you won’t be able to see much.
For general space lighting, the U.S. Department of Energy suggests you shop for light that is in the range of 450 to 1,600 lumens per bulb.
How Lumens Effect LEDs Color Temperature
The color temperature of a light source is in reference to warmth or coolness of the hue. The Kelvin Scale measures the appearance of a light source’s color temperature. The scale is based on metals absolute temperature when heated.
The longer the metal is heated, the more its color changes from red to blue-white. The low end of the degrees-kelvin scale is warm in tone, leaning towards red-orange. The high end of the scale is cool in tone, close to a blue-white color. The high end of the Kelvin scale is closest to daylight.
Most lighting instruments are on the Kelvin scale from 2700 Kelvin to 6500 Kelvin. LEDs can very much more on the scale, to produce warmer or cooler light.
The more lumens in your LED, the cooler the color of the light. Cool lighting is better for visibility. Warm lighting is better for relaxation.
LEDs for your home will mimic the light of a traditional filament bulb, at around 2700 Kelvin. Vintage styles are lower, around 1900 Kelvin, producing Edison bulb style light.
The question, of how many lumens is enough, depends on your preference of lighting color. Do you want bright lighting for an office? Go with LED lighting that is cool in color and high on the Kelvin scale. Looking for LED lights for relaxing in your home? Get LEDs low on the Kelvin scale, warm in color, and low in lumens.
Lumens per Square Foot
So, the more lumens, the brighter the light. The brighter the light, the cooler its color temperature, represented by a higher number on the Kelvin scale.
To figure out how many lumens you need per light depends on the size of the room. Use a square footage calculator to get the proper measurement of the space to be lit. This will determine the number of lights you should incorporate into your LED lighting design.
The Illuminating Engineering Societies handbook on lighting suggests floors be lit with at least 20 lumens per square foot. Tabletop surfaces and other raised objects should be lit with at least 30 lumens per square foot. Use at least 50 lumens per square foot to provide higher visibility to workspaces, desks, and areas of productivity.
Consensus on LED Lighting: How Many Lumens is Enough?
Living rooms, that are about 250 square feet, will need eight individual 10-watt LED lights. That will produce around 5,000 lumens of brightness, spread out to cover each square foot with 20 lumens, each.
For reading area’s, like your couch or desk, you want 200 lumens. For task area’s, where focused lighting is needed, four square feet of 50 lumens each will do the trick.
If LED Lighting: How Many Lumens is Enough helped you, leave us a comment. If you are still wondering about how many lumens you should use, leave a question in the space below and explore more of our lighting resources. Thanks for reading!