The age of a bulb can undoubtedly affect its lumen output or brightness. Incandescent bulbs pass an electric current through a thin filament, which heats up and emits light. Over time, the filament can become worn out and even break, causing the bulb to produce less light.
Fluorescent bulbs use gas and a small amount of mercury vapor to produce ultraviolet light. The ultraviolet light then causes a phosphor coating on the inside of the bulb to glow and emit visible light.
However, as you mentioned, the phosphors can degrade over time due to exposure to heat and light, which can cause the light to produce less light and appear dimmer. The degradation of the phosphors is a gradual process, and over time the bulb’s lumen output can decrease by as much as 30 percent.
In addition to phosphor degradation, the overall performance of fluorescent bulbs can also be affected by other factors, such as the quality of the ballast used to regulate the electrical current in the bulb. For example, a malfunctioning ballast can cause the bulb to flicker or not turn on at all.
It’s important to carefully handle and dispose of fluorescent bulbs, as they contain small amounts of mercury that can harm human health and the environment.
In both cases, the decrease in lumen output as a bulb ages is a normal part of the bulb’s lifespan and is something that users should be aware of when considering when to replace their bulbs. It’s also worth noting that some types of bulbs, such as LED bulbs, may experience less of a decrease in lumen output over time compared to incandescent or fluorescent bulbs due to their more efficient design.
LED bulbs are generally designed to maintain their lumen output for much longer than traditional incandescent or fluorescent bulbs. While all light sources will inevitably experience some degradation over time, LED bulbs are typically designed to have a much longer lifespan and maintain their brightness for extended periods.
LEDs are solid-state devices, meaning they don’t have a filament that can wear out or phosphors that can degrade as incandescent and fluorescent bulbs. Instead, they work by passing an electric current through a semiconductor, which emits light. This means they are less prone to the gradual decrease in lumen output that can occur in other bulbs.
While LED bulbs can still experience some decrease in lumen output over time, it is generally much less noticeable and happens over a much more extended period. LED bulbs can last tens of thousands of hours, much longer than incandescent or fluorescent bulbs. Additionally, they are more energy-efficient and generate less heat, which can help extend their lifespan.