News

Home » News

Has anyone ever told you that you shouldn't turn off lights if you'll need to turn them on again within a few minutes? That it takes more energy to turn the light back on than to leave it on?

Saturday 3 December 2011

I don't know where this idea came from, but it just isn't true.

Has anyone ever told you that you shouldn't turn off lights if you'll need to turn them on again within a few minutes? That it takes more energy to turn the light back on than to leave it on?

I don't know where this idea came from, but it just isn't true.

What's the theory behind it?

People think there's a power surge when you turn on a light, and that this surge uses as much as fifteen minutes of what the bulb normally uses. So the misguided assumption is that it's better to leave lights on than to turn off lights you'll be needing in the near future.

All right you say, but won't you wear bulbs out if you turn off lights too often?

Yes,you will wear a bulb out sooner. All you have to do is watch a 5-year-old (of course not a P1 in St Colman's) switch a light on and off five times a second for a few minutes, then watch the bulb burn out, to realize that frequent on-and-off action for a light bulb does indeed wear it out. But we are not talking about rapid on-and-off cycling. We are talking about a cycle that lasts a minute, five, or fifteen minutes or more.

You will save both energy and money if you turn off lights whenever you leave a room, even if you plan to come back a minute later.

What about distractions when you don't turn off lights?

If you make it a habit to turn off lights whenever you no longer need them, they'll stay off until you come back. You might think you're coming back in two minutes, or five or fifteen. But what if something comes up? What if a long phone call, a visit from a neighbor, or a quick run to the grocery store keeps you away longer than the five minutes you planned?

And what if you just plain forget about the light you left on? Then the five minutes can become five hours (for a bedroom or bathroom light, for example), or even five days if it is lfor a light in a room you rarely visit such a cupboard under the stair or the roofspace.

We summarised this from an interesting website we found. Click here if you want to read the full article (It's American and not that interesting for kids but your parents might be interested) - wwwdots