Luminous Efficacy and Useful Lumens: A Comprehensive Guide to Efficient Lighting Design
- By Ledrise Led Professional
- Feb 10, 2023
Luminous efficacy measures how effectively a light source produces visible light. With LEDs and other light sources, luminous efficacy is the ratio of luminous flux to electrical power, known as lumens per watt (lm/w). For example, the light output (luminous flux) of a 1 Watt LED can be very bright for high efficacy or barely visible for low.
The luminous efficacy is one of the defining factors of LED performance. Top performance LEDs, with the highest luminous efficacy, have 220 lumens per watt (lm/w), such as the Nichia 757G LEDs. High performance LEDs, like those from many other manufacturers, have 150-200 lm/w. At the far end, we have the low cost, poor performance LEDs with an efficiency of less than 99 lumens per watt.
| Top performance LED | High Performance LED | Good Performance LED | Poor Performance LED |
| 220 lm/W | 150-200 lm/W | 100-149 lm/W | 50-99 lm/W |