Eddy Current
Senior Member
I know that CFL's don't just go out they get dim as they get older, but by being dim are they actually using more energy to stay lit or less energy?
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Dim CFL using more energy?
- Thread starter Eddy Current
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- Location
- Placerville, CA, USA
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- Retired PV System Designer
I know that CFL's don't just go out they get dim as they get older, but by being dim are they actually using more energy to stay lit or less energy?
At least three effects:
1. Gas in tube gets contaminated, producing less light in the spectrum that the phosphorus is sensitive to.
2. Phosphor gets less efficient in producing visible light.
3. Current in arc goes down.
1 and 2 will reduce light output but not power consumed. 3 will reduce both.
And 4: electronic ballast could lose efficiency as components age. This could even increase power consumption while reducing output.
Which effects dominate may vary by manufacturer.
Eddy Current
Senior Member
Ok so i guess it mostly depends on the type of electronic ballast.
broadgage
Senior Member
- Location
- London, England
Measurements that I have made on a number of CFLs suggest that in practice, that the power consumed does vary much much during life.
At work I use large numbers of 15 watt CFLs, I have measured the power used by new and well used examples and found it to be a little under the nominal wattage for both new and used lamps.
I usually replace most of the lamps before failure.
For example if a toilet area contains 8 such lamps, I wait until 1 fails and then replace all 8. I sometimes re-use the old but functioning lamps in areas that are liable to lamp theft.
The light output declines noticeably as the lamps age. I dont go so far as to measure it, but an area lit by just replaced lamps is noticeably brighter.
These are 230/240 volt lamps, but I would expect that USA type 120 volt ones would behave similarly.
At work I use large numbers of 15 watt CFLs, I have measured the power used by new and well used examples and found it to be a little under the nominal wattage for both new and used lamps.
I usually replace most of the lamps before failure.
For example if a toilet area contains 8 such lamps, I wait until 1 fails and then replace all 8. I sometimes re-use the old but functioning lamps in areas that are liable to lamp theft.
The light output declines noticeably as the lamps age. I dont go so far as to measure it, but an area lit by just replaced lamps is noticeably brighter.
These are 230/240 volt lamps, but I would expect that USA type 120 volt ones would behave similarly.
RonEl
Member
- Location
- Defiance, Ohio USA
Measurements that I have made on a number of CFLs suggest that in practice, that the power consumed does vary much much during life.
At work I use large numbers of 15 watt CFLs, I have measured the power used by new and well used examples and found it to be a little under the nominal wattage for both new and used lamps.
The second sentence appears to say that power usage does not vary for new and used lamps; but the first sentence says "power consumed does vary much". They seem to be saying opposite things, am I missing something?
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RonEl
Member
- Location
- Defiance, Ohio USA
messed up.
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