Lumen Depreciation

In the lighting industry, there are a lot of terms commonly used by insiders. If you aren’t as familiar with the ins and outs of lighting, you may have a few questions about certain terms. When it comes to lumen depreciation, there is a lot of confusion regarding this aspect of illumination. Let’s take a closer look at lumen depreciation and how it affects the decision process when choosing lamps or fixtures.

What is lumen depreciation?

Lumen depreciation is simply stated as the loss of lumen output over a period of time in any given lamp. Most lamps naturally reduce the lumen output over time but to varying degrees depending on type. It is important to note that lumen depreciation isn’t the same thing as burning out a lamp. Lumen depreciation is when lumens are lost gradually over time due to repeated use. For instance, if a lamp produces 900 lumens when brand new and in five years only produces 700 lumens, that is a depreciation of 200 lumens.

Why does it matter?

The reason lumen depreciation is important is because most spaces require a specific number of lumens to ensure proper illumination. If the space loses these lumens over time, it will become dimmer in the room or area. It is also a matter of value for the money invested. For example, if you are constantly using lamps with higher lumen depreciation, you will need to replace them more regularly to maintain the lumen needed for the space.

Are certain lights better than others in this aspect?

When looking for a lighting solution that offers the best in lumen retention over the years of use, there is really only one choice towering above the rest on the market. LED lights offer the best lumen retention over comparative lamp models. While LED still has a lumen depreciation over time, it is considerably lower than other options such as metal halide, compact fluorescent, or incandescent. The rate of lumen depreciation is calculated in percentages of comparing the full lumen output and the average rated life of the lamp. Most metal halides and fluorescent have a lumen depreciation rating of 50% whereas LED has a rating of 70% which means an LED retains up to 70% of its initial lumen output at the end of the expected life rating period.