I notice that a compact florescent lamps (CFL) wear out faster than its lifetime. My personal experiment was on 15 watt / 220 V / 50-60 Hz / 690 Lumen spiral lamp. Its rated lifetime is 8000 hours (about 11 months). But it is burned after 3 months only. It is repeatedly happens that each new lamp live for 3 months only then it is burned. What could be the reason? I don't light the lamp all the day. I light it while the periods of breakfast, lunch and dinner.

I guess it is the temperature, because a lamp is rated for -5 deg to 40 deg and I live in a country where the temperature reaches 40 deg. So, I think the temperature inside the lamp is higher than 40 deg and the lamp is overheated.

Thank you very much,

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    \$\begingroup\$ I think you are right. "Over long periods of time, elevated temperatures may shorten ballast life and consequently reduce lamp life in self-ballasted HW-CFLs." lrc.rpi.edu/programs/nlpip/lightingAnswers/HWCFL/… \$\endgroup\$
    – Dampmaskin
    May 28, 2016 at 9:16
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    \$\begingroup\$ YOU may have adverse conditions that are decreasing lifetimes, but low quality is a better guess. | 8000 hours is a rating applicable to good quality well designed CFLs operating in reasonable conditions. The decrease in CFL prices over time and the competition from LED lights means that cutting corners, lowering quality and producing a product which comes nowhere near the 8000 hour lifetime. Now treat it harshly and it dies far far sooner than expected. || Parallel example: About 4 years ago when LED lights often claimed 100,000 hour LED life there was ONE manufacturer wordlwide ... \$\endgroup\$
    – Russell McMahon
    May 28, 2016 at 13:55
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    \$\begingroup\$ ... whose through hole white LEDs exceeded 10,000 hour lifetimes. [That was Nichia, 'inventor' of the white phosphor LED]. FWIW that's not a stat that you'll easily find mentioned anywhere. I was told this by Nichia technical staff and believe it is 'true enough'. [Through hole LEDs use epoxy housing which are fundamentally low life. SMD LEDs mostly use Silicon lenses which have a far longer lifetime in optical power encapsulation applications. \$\endgroup\$
    – Russell McMahon
    May 28, 2016 at 13:59

1 Answer 1


Filament lamps have a lot going for them. They can soldier on running at temperatures that would happily destroy the lamp fittings.

However, the electronic ballasts in CFLs are very sensitive to over temperature. I tried to use some 5 watt CFLs in some enclosed ceiling downlighters that previously had used 50 watt halogens, and failed to get more than 1 month out of them.

Be aware that some manufacturers may make their lamps more robust than others. Higher priced brand name producers might be more likely to use high temperature electrolytics and decent derating on the transistors than the lower prices copies that can be obtained.

Are you using the CFLs in enclosed fittings designed for filament lamps?

I would be a little surprised to learn that a free-flowing ambient of 40C was too much for decent life from a CFL, but would not be astonished.


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