Do CFLs Need to Warm Up?
It’s a popularly held belief that CFLs use a lot of energy to warm up and that it is better to leave them on—rather than turning them off for short periods of time. Is this true? Or, does it always save energy to turn off CFLs? What about other types of bulbs? Check out this post to illuminate the truth.
The cost effectiveness of turning off a bulb depends on the type of bulb and the cost of electricity. First, all light bulbs have an operating life. For some types of bulbs, the more times you turn them on and off, the shorter their operating life. Second, if you live in an area with higher energy costs, then you’ll save more by turning off your lights.
Incandescent Bulbs Should Be Turned Off
Incandescent bulbs are the least efficient type of lighting and should be turned off when they are not needed. Ninety percent of the energy they use is given off as heat—only 10 percent results in light. Turning these lights off will also keep your home cooler in the summer, reducing the demand for air conditioning.
Halogen Bulbs Should Be Turned Off
Halogen bulbs are more efficient than traditional incandescent bulbs. However, they are far less efficient than CFLs or LEDs. Therefore, these bulbs should be turned off when they are not needed.
Follow This Rule of Thumb for CFLs
The savings from turning CFLs off is more complicated to calculate due to several factors.
- CFLs are already very energy efficient when compared with incandescent and halogen bulbs. So you will not see as big of a savings by turning CFLs off as you would with those bulbs that use more energy.
- Also, compared to incandescent and halogen bulbs, the operating life of CFLs is more affected by the number of times they are switched on and off.
So, the question is, “how much electricity will you save by switching off the lights relative to the shortened life span from turning the bulb on and off?” The Department of Energy has information that can help you calculate this. However, you can also follow these simple guidelines to save energy and while preserving the life of your CFLs:
- If you will be out of a room for 15 minutes or less, leave it on.
- If you will be out of a room for more than 15 minutes, turn it off.
LED Bulbs Should Be Turned Off
LED bulbs are more energy efficient than CFLs. Therefore, you will not save a lot of energy by turning them off. However, switching an LED bulb off and on does not shorten its operating life. Since there is no negative effect from switching these bulbs on and off, it is best to turn them off when not needed.