Back in 2007, the Energy Independence and Security Act (EISA) was passed by congress. The act gave notice to inefficient lighting systems. The law mandated stringent new energy standards that were meant to usher in a new era of greener, long-lasting, efficient light bulbs, and this meant getting rid of old, inefficient light bulbs.
If you’ve decided that LED technology is the way to go, you’ve made a good decision. However, LED technology is vast and you may be confused by all the specifications. What are lumens? What are watts? What is color temperature?
Don’t worry about all these specifications because that’s what we’re here for. In this post, we will define the most common specs you need to know about LED technology.
Without further ado, let’s get started.
1. Watts (Wattage)
One of the first LED specs you’ll see, or hear, is watts (or wattage). Watts are very important because they are a measurement of power.
Watts accurately measure the electricity a bulb needs in order to light up.
Most manufacturers use the wattage of a LED bulb as the selling point, and with good reason. LEDs consume very little electricity and need very few watts to produce adequate light. Their low energy consumption, is without a doubt, one of their best features.
2. Replacement Wattage
Back in the day, when you wanted to replace a burnt out light bulb, all you had to do was look at the wattage of the old bulb and get a new bulb with the same wattage. But when it comes to LED lighting, replacing traditional lights doesn’t simply mean matching the wattage.
Replacement wattage is a specification you will see on most LED light labels. It simply means the wattage of the conventional light being replaced by the LED light.
This specification is very important as it helps you to buy a LED bulb that is a perfect replacement for a traditional bulb. For instance, a LED lamp that consumes 100 watts may replace a 400-watt metal halide or high pressure sodium lamp.
Nothing is as important in determining the light output of a bulb as the lumens.
If you’ve been looking at the watts to know how bright a bulb is, you’ve been looking at the wrong specification.
Lumens measure the total quantity of visible light (the light seen by the human eye) produced by a light source. The more lumens a LED bulb produces, the brighter it will seem.
Lumens are vital as they help you to know how bright a LED bulb is compared to a traditional light source. When you know the lumens a LED light produces, you’ll know if it is bright enough to replace a specific traditional lamp.
4. Lumens Per Watt (Luminous Efficacy)
To know how efficient a LED bulb is, look at the lumens per watt. While lumens measure the visible light a bulb generates, lumens per watt (lm/W) measure how many lumens are produced for each single watt of energy a bulb consumes.
Is luminous efficacy important? Absolutely.
The higher the luminous efficacy, the more efficiently a light source performs. As LED technology continues to advance by the day, efficacy ratings keep on improving.
When LEDs were first introduced, they produced approximately 50 lm/W. These days, most LEDs sold on the market emit more than 120 lm/W. A useful rule of thumb is to never buy LEDs that produce less than 100 lm/W.
5. Rated Life
You have probably seen this specification on the packaging box of a LED light.
So, what exactly does it mean?
Rated life means how long a bulb will operate before getting to 70% of its initial brightness.
Research has shown that the human eye cannot detect a gradual loss of light output until a bulb emits less than 70% of the light it produced when it was new. At that point, our eyes will say, ” This light is not bright enough, it needs to be replaced.”
The rated life of traditional light sources is usually the time period they are expected to function before burning out. However, LEDs don’t usually burn out. Their light output gradually decreases over time.
LED manufacturers use the L70 rating to describe the time it will take for a bulb’s light output to reach 70% of the original output. During their entire lifespans, LEDs must retain 70% of their initial lumens. The rated life of a LED bulb is when the light is expected to produce 30% less lumens than it did when it was brand new.
But since LEDs have such a long lifespan (their average lifespan is 50,000 hours), they generate high-quality light for many years. They produce 70% of their initial lumens until they reach the end of their lives.
6. Color Rendering Index (CRI)
Color Rendering Index (CRI) may be a difficult term, but we’ll try to simplify it as much as we can. CRI measures the ability of a light source to show the true colors of objects in comparison to a perfect or a natural light source – such as sunlight.
Color rendering defines how a light source makes the colors of an object seem to human eyes. It also describes how well a light reveals small differences in color shades. The Color Rendering Index ranges between 0 and 100. The higher the CRI, the better a light’s color rendering ability. Light bulbs with a CRI between 80-90 are considered good at color rendering while those with a CRI of 90 or higher are excellent at color rendering and can be used for tasks that require accurate color discrimination (like textile manufacturering).
While CRI might not be very important in some settings, it is very important in others – like grocery stores (where people need to see how fresh the food products are) and areas where security is crucial.
7. Color Temperature
Color Temperature, whose official term is Correlated Color Temperature, is a number that indicates the color of light a light source emits. A low number normally indicates that the light is warm (red and orange shades) – like the light emitted by a candle or a fireplace. A high color temperature indicates that the light is cool (blue and white shades). The standard range is usually between 2700k (for warmer lights) and 5000k (for cool lights).
Lights with a high Correlated Color Temperature tend to look brighter. LED manufacturers often make LEDs with low wattages and high color temperatures to make them appear brighter. Cool lights are mostly used in industrial spaces where very bright light is needed for enhanced productivity. If your building has traditional lighting and you’re converting to LED technology, find out the color temperature of your current lights so you can get the best replacements.
8. Center Beam Candle Power
This rather complicated term measures the light intensity at the center of a light beam. When lighting designers want to know whether a light bulb is bright enough, they don’t just look at the lumen output, they also look at the Center Beam Candle Power as it is a very important measurement for accent and spot lighting. This is because they know that a light source can have a high lumen output but a low CBCP.
What does this mean?
A light with a high lumen output and a low CBCP spreads out light over a large area. And while this light may be ideal in some applications, it is not suitable when you are trying to draw attention to a specific product (like a piece of art) or a section of a room.
The right LED light for spot and accent lighting may have lower lumens than its counterparts, but its light will be concentrated at the center of the beam.
Because LEDs have very low wattages, many types of dimmers don’t work well with them as they do with high-wattage traditional lights. When you pair them with dimmers, you may notice that they do not shift color when dimmed, they may not go off at the lowest dimmer setting, and their dimming range may be lower (70%-90% vs. 100% with conventional lights).
A LED manufacturer will usually indicate if the driver inside a LED is dimmable and which system the LED dims with (3 phase, 0-10v, etc.). If you want dimmable LEDs, make sure the ones you buy are rated dimmable.
Selecting the Right LED Lights For Your Building
Now that we’ve told you all about the important specs of LED technology, let us give you a few pointers on how to go about buying LED lights. While all the features we mentioned here are important, there are some you should give special attention to.
If you want bright light, the most important thing to look at are the lumens as they will determine how bright the LED is. Next, look at the wattage as this will help you to choose LEDs that only consume a few watts.
Color Rendering Index and Color Temperature are also very important as they determine how accurate a light is at revealing the true colors of objects and how bright the light seems. Lastly, look at the rated life and any additional features you may want in a LED light. If your work environment needs accent or spot lighting, pay special attention to the Center Beam Candle Power.
Getting new LED fixtures is the way to go if your building is still being constructed or if you are in the process of redesigning it. These fixtures will lower energy consumption and provide many years of service. Or if you have fixtures in place, and want to convert them over to LED, then consider a retrofit system.
However, if your building has conventional lights and you’ve decided that switching to LED is the best financial decision, you can choose retrofitting. A lighting expert will simply recommend the best bulbs for your existing fixtures – if they are fully functional. The traditional bulbs will simply be replaced with LED bulbs, making the transition as easy as can be.