Archive for November, 2010

CFL lifetime is short

Nov 2011 –
nvision (14 watt) Aug 09

Nov 2010 – original entry
Going to start tracking how often I replace CFLs as I”m starting to accumulate them. I write the install date on them as a way to make sure I’m not imagining that they don’t last very long. These are all typical household uses, nothing extreme. These are all the normal spiral CFLs (I also have the reflector type in some recessed fixtures – they are awful in that they take minutes to warm up to full brightness – some I replaced with normal incandescent because a hall light that takes minutes to be useful is pointless). There’s about 15 CFLs in use right now.

Looking in the recycle box (they shouldn’t go  in the trash, and they won’t take them back as hazardous waste…) I have 10 dead bulbs. Some of these have been in there for a year, the one I just added today was dated Feb 07.  The install dates:

  • Nov 07 (nvision)
  • Dec 06 (nvision)
  • Dec 07 (Sylvania)
  • Mar 10 (Sylvania)
  • May 08 (unmarked)
  • Feb 07 (commercial electric)

undated: 4 bulbs, but look to be of the same vintage as the dated ones.

So this is around a 50% failure rate in 4 years.  Now I haven’t kept track of incandescent bulbs, but I don’t think they fail more than this and there are bulbs in some (newer) fixtures where I know I have replaced 1 of 6 and it’s going on 8 years. Not really good enough sample sizes to draw solid conclusions, but it seems to be consistent with other anecdotal reports that CFLs don’t last anywhere near as long as the package says, and therefor the cost savings are going to be small to negative (and I would guess it takes more energy to make a CFL than incandescent? Are these things carbon neutral when they only last for half their rated life?)

Saturday, November 20th, 2010 CFL lifetime No Comments