Leave ’em on or off? When to turn off the lights.
The other day I was fiddling around in my apartment going from room to room, and after about 10 minutes I realized I was constantly turning on and off the lights. I stopped and wondered if I should keep turning them on and off or just keep them all on. I did some research and would like to share my findings.
Rule of thumb: Turn the light off if you are leaving the room for more that 3 minutes.
Incandescent bulbs use energy very inefficiency (90% is wasted) when they are on, so it is good to turn them off if you wont be in the room for even a couple of minutes. It does wear on the bulb a little (avoid trying to turn your kitchen light into a strobe), but not enough to counter act the amount of energy it uses in a few minutes. Also, the idea that lights power surge when they are turned on is false and not an issue you need to worry about.
Compact Fluorescent Light (CFL):
Rule of thumb: Turn the light off if you will be out of the room for more than 15 minutes.
The amount of times you turn CFLs on and off matters. There is added stress on fluorescent bulbs when they are turned on, which can wear on the bulb, and reduce its lifetime. Plus CFLs use 75% less energy than incandescent bulbs which means that leaving them on longer before turning it off is best for the bulb and your wallet.
Light Emitting Diode (LED):
Turning LEDs on and off frequently has no impact to their lifetime.