Low energy bulbs: is the peak cost the initial switching on?

[Deansplit]

Is it less cost effective to keep turning LE bulbs off as per a halogen bulb? I am under the impression that the initial warm up time at the start where they are quite dim (the most annoying part in m y mind!) is when they use most power. I was once told a story about a factory which used a large amount of florescent strip lights, and it cost the company more to turn the lights off during the lunch hour than to keep them on, due to the starters using maximum power to illuminate. So wondered if this is the same with LE bulbs?

Thanks

 

[ericmark]

The start current is for a short time so energy wise over a 5 min break switching off would save energy but they have a limited number of starts and take time to warm up to get full output so half an hour would seem a sensible time so in my house kitchen, dinning and living room once switched on stay on but landing, bathroom, loo and bed rooms are switched on only as required.

Discharge lamps have heaters to start them and so do use extra on start but each type will take a different amount extra and in factories with low and high bay lighting it can take up to 5 min to warm up again and special emergency lamps are required so after a power cut and return of power they stay on for 5 min to allow the main lights to re-light. Small domestic lamps don't have this problem.

 

[AndrewDavie]

They tested this on mythbusters (And for once, they used a reasonably scientific method!)
For an ordinary domestic energy saver bulb, the result was that if you were leaving the room for longer than 30s, then turn it off.
OTOH, turning off and on all the time _did_ significantly reduce the lifespan - but as you can still get 5 for £1, I don't think the cost of replacing the bulb is a problem.

 

[Steve]

10p each at B&Q, even though the SEL reads £1.93 for the GE ones.