What is lumen depreciation?

Lumen depreciation refers to the gradual decrease in light output from a lighting source over time. This phenomenon is particularly important to consider when designing lighting systems, as it affects the overall performance and efficiency of a lighting installation. Various factors contribute to lumen depreciation, such as the aging of bulbs, accumulation of dirt on fixtures, and changes in surrounding environmental conditions. Understanding lumen depreciation allows lighting designers to plan for maintenance and replacement schedules, ensuring that the desired illumination levels are maintained over the lifespan of the lighting system.

In contrast, the other options address different aspects of lighting. An increase in brightness over time does not occur with most lighting sources; rather, they typically experience a decrease in output. Measurement of energy efficiency focuses on the amount of light produced per unit of energy consumed, which is not related to lumen depreciation. Finally, a standard for bulb lifespan relates to the average duration bulbs are expected to last before failure, rather than their output decline over time.