what is the truth about leaving fluorescent bulbs on rather than switching them off and on?

Question

I have heard conflicting things about this, some ppl say always turn off, others if you are not going to use them for a few minutes, others say better to leave them on all night than turn them off and on

Answer 1

A 40 watt bulb at 120 volts consumes 4.8 amps of energy per hour.

If the start up wattage for the same bulb is approximately 2000 watts (a wild guess) for 1 second at 120 volts = 0.067 amps If it is 5 seconds, it would be 0.201 amps.

So, if you are going to leave a room for more than 15 seconds, it is better to turn the lamp off than to leave it running from an energy conservation standpoint.

Answer 2

Turn them off if you will be gone for more than about 15-20 minutes.
There are a few misconceptions about fluorescent lighting that keep too many people from turning lights off to save energy. The first misconception is that it takes more energy to start a fluorescent light than it takes to run it. The second misconception is that turning a fluorescent light off and on will wear it out right away. Like many of our myths about energy, there is a small amount of truth in the belief.