Before buying your LED replacement bulbs, you need to understand the basics of Correlated Color Temperature (CCT), Lumens, Color Rendering Index (CRI), and the equivalent wattage of your current lamp.
Color Temperature - (a.k.a. CCT) is measured in between 1000K to 10000K. Most LED lamps are tuned between 2700K to 6500K. The lower the temp the warmer the light (yellow color). The higher the temp the whiter it is. Anything over 5700K will start emitting into the blue spectrum. The mood of a room is often set by how warmly or coolly the light emits. You are more likely to pick a 2700K to 3000K A19 bulb for your home to set a softer and calmer tone. While you would consider a 4100K to 5000K bi-pin LED T8 tube for your office to raise productivity.
Fun fact: Kelvin is a unit of temperature. The abbreviation K is used in the lighting industry to let you know how much white light is being given off by a bulb. The lower the Kelvin, the more yellow the light appears.
Lumens - Lumen or luminous flux is the true measurement of light being emitted, while wattage is the measurement of power consumed. Therefore, we need to retrain ourselves to buy lights based on the number of lumens and not wattages. The lighting industry has corrected itself and labelled most LED bulbs in terms of lumens.
Color Rendering Index - (also known as CRI) is the measure of a light source's ability to display color in its natural form. 'Natural form' means how a color should look under full sunlight. The CRI reflects a rate of accuracy, so it ranges from 0 to 100. The higher the CRI, the truer the color you see. Most commercial warehouse light fixtures are tuned with a CRI of around 80 because there is little need to make sure that colors appear truest to their actual hue. While a jewelry store or paint body shop will likely select a lamp with a CRI of 90 or higher because color precision matters so much in those kinds of highly visual industries.
Equivalent Wattage - At the end of the day, you just want to know which LED bulb is equivalent to your burnt-out HID lamp. Many times, an LED light fixture still includes wattage numbers of their packaging alongside the number of lumens. To make things even more complicated, not all LED lamps are created equal. Some have better efficacy than others. Not all 100W corn bulbs emit the same lumens just because they’re using 100 watts of power. It is important for you to compare the lumens output and not wattage. If you still want to know what wattage you need, you can follow these basic formulas to estimate the LED wattage equivalent. While these figures aren’t exact, they will get you close to the number you’re looking for.
- For incandescent bulbs, divide the wattage of your current bulb by 7 or 8.
- For fluorescent tubes or CFLs, divide the wattage of your current bulb by 2 or 3.
- For metal halide (MH) lamps, divide the wattage of your current bulb by 3 or 4.
- For high-pressure sodium (HPS) bulbs, divide the wattage of your current bulb by 2 or 3.
Efficacy - Although we didn’t mention efficacy on our original list, we though it was worth mentioning in order for you to understand wattage equivalent. Efficacy is the number of lumens emitted per watt. For example, a 150-watt LED high bay can be from 15,000 lumens to as high as 28,500 lumens depending on its efficacy. While a 400W HPS bulb will likely just emit about 40000 lumens with only 20000 usable lumens. In basic term, the higher the efficacy, the more efficient that lamp is in producing light. Now we hope you will have a better understand of why not all LED light bulbs are created equal.
Either you are in the market for a flush mounted LED ceiling light or our new popular 2 by 4 LED panel, these basic concepts will guide you in making better decision for your next lighting project.