As many of you know I am an engineer by trade, my disciplines are in both mechanical and electronics. I spend most of my days knee deep designing, developing and troubleshooting electrical systems, specifically in the lighting industry. One thing that I have seen many people talk about (and have had many emails about this myself) is whether it really saves electricity to turn off the lights when you leave the room, especially if you know you are coming back in a minute or even a couple minutes. Read: many people talk about it and speculate… but how many of them can prove it?
When I am cleaning house, I bounce around room to room like a chicken with my head cut off trying to pick things up, sometimes I leave the lights on merely for convenience… but still one has to wonder about the old wives tale that it uses less electricity to leave the lights on.
The train of thought that most people have is that when a light bulb (incandescent, florescent, CFL, neon, LED) is turned on, it draws more current when first powered up.
Here’s proof: I took a 60W incandescent light bulb and monitored the current on my oscilloscope (an instrument that takes measurements vs time), here is the results. Notice the large spike of current when first powered on? This is the inrush current. Nominally this inrush current is about twice the steady state current.
I don’t know about you guys, but I usually leave the room for more than .1 seconds at a time… Usually… LOL.
This means that it always saves money to turn them off when leaving the room, even when it is for 0.10 seconds.
Hope you found this informational. As a science dork, I just thought it would be fun to prove this myth either way.
Don’t forget to turn out the lights!!!