The lifespan of a bulb is typically prominently displayed on the bulb’s packaging to help consumers weigh its effectiveness. Be aware though that the lifespan of some bulbs might not actually measure up to the number on the box.
CFL Lifespan Issues
The problem associated with CFL bulb lifespans is mainly due to differences in the way the bulbs are tested – in 3 hour increments – versus how they are used in the real world. Turning a CFL bulb on and off in shorter increments can significantly reduce its lifespan.
That said, CFL bulbs are much more efficient than incandescent bulbs and can significantly reduce your power bill.
For more information on how to get the most out of CFL bulbs, read the Department of Energy’s article on “When to turn off your lights.”
Usage Frequency Matters
The average light bulb in a home gets used less than 2 hours per day. However, there are big differences between the bulbs that get the most use versus the bulbs that get very little use, like the lights in your closet.
Bulbs on the upper end of the use range, like the lights in your kitchen, may be used an average of 4 hours per day. At 4 hours per day, a bulb with a 25,000 hour lifespan will not need to be changed for more than 17 years. For bulbs that get very little use, such as those in your closet, installing a bulb with a 25,000 hour lifespan means that you will likely never have to change the bulb again.
For a complete breakdown of bulbs and their efficiency, read our in-depth post “Lightbulb Efficiency Comparison Chart“.