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Science Forum Index » Engineering - Lighting Forum » Does altitude affect CFLs lifetime?...
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 Posted: Fri Jun 20, 2008 11:46 am |
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I have lived in Colorado, at 6300 feet (1920 meters) elevation, for
the past 7 years. In that time I have purchased CFLs, mostly from
Lowes (hardware store), but probably some from Walmart as well. My
experience has been that they do not last as long as advertised (6-7
years).
I've been trying to figure out why. Perhaps we are buying cheap bulbs
that are just not assembled well? Perhaps we have old wiring/fixtures
(our house is 39 yrs old) that is not providing constant voltage to
the bulbs, and thus wearing them out faster?
My guess is that the relatively high altitude has something to do with
it.
I haven't kept track, but in the 7 yrs we've been here, we've replaced
many of the CFLs we installed after moving here and it seems to be
almost as often as the cheaper incandescents. In the future, I hope
to actually track the lifetimes of all the bulbs in my house, but
until then I'm looking for answers from you.
Thanks in advance |
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| Andrew Gabriel... |
| Posted: Fri Jun 20, 2008 5:06 pm |
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In article <f4e0eb00-c636-4c6f-9745-97d4adeb675c at (no spam) a1g2000hsb.googlegroups.com>,
kettnernw at (no spam) yahoo.com writes:
Quote: I have lived in Colorado, at 6300 feet (1920 meters) elevation, for
the past 7 years. In that time I have purchased CFLs, mostly from
Lowes (hardware store), but probably some from Walmart as well. My
experience has been that they do not last as long as advertised (6-7
years).
I've been trying to figure out why. Perhaps we are buying cheap bulbs
that are just not assembled well? Perhaps we have old wiring/fixtures
(our house is 39 yrs old) that is not providing constant voltage to
the bulbs, and thus wearing them out faster?
My guess is that the relatively high altitude has something to do with
it.
I haven't kept track, but in the 7 yrs we've been here, we've replaced
many of the CFLs we installed after moving here and it seems to be
almost as often as the cheaper incandescents. In the future, I hope
to actually track the lifetimes of all the bulbs in my house, but
until then I'm looking for answers from you.
They aren't really rated in years -- they are rated in hours used.
If you look at the packaging (at least in the UK), you will find
the assumptions used to work that out, which are probably 3 hours
use per day. If you use them 9 hours a day, then you'll only get
1/3rd of the 7 years.
Convection cooling becomes less effective at higher altitudes.
This would cause electronics to operate at higher temperatures and
more likely to fail, particularly in [semi-]enclosed fittings.
--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup] |
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| Victor Roberts... |
| Posted: Sat Jun 21, 2008 9:08 am |
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Guest
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On Fri, 20 Jun 2008 14:46:33 -0700 (PDT),
kettnernw at (no spam) yahoo.com wrote:
Quote: I have lived in Colorado, at 6300 feet (1920 meters) elevation, for
the past 7 years. In that time I have purchased CFLs, mostly from
Lowes (hardware store), but probably some from Walmart as well. My
experience has been that they do not last as long as advertised (6-7
years).
I've been trying to figure out why. Perhaps we are buying cheap bulbs
that are just not assembled well? Perhaps we have old wiring/fixtures
(our house is 39 yrs old) that is not providing constant voltage to
the bulbs, and thus wearing them out faster?
My guess is that the relatively high altitude has something to do with
it.
I haven't kept track, but in the 7 yrs we've been here, we've replaced
many of the CFLs we installed after moving here and it seems to be
almost as often as the cheaper incandescents. In the future, I hope
to actually track the lifetimes of all the bulbs in my house, but
until then I'm looking for answers from you.
Thanks in advance
I was going to say that altitude does not have any impact on
CFL life, but Andrew makes an interesting point regarding
convection cooling. I'll have to check some data to find
out of the lower air pressure at 6300 feet makes a
significant difference.
The only other issue is your power line voltage. If it is
higher than normal then the lamps may run hotter than
normal, which would reduce life. The voltage is not related
to altitude.
Andrew is also correct that the lamps are rated in operating
hours. If you operate one for 24 hour a day, it may last
less than one calendar year, which is 8760 hours.
--
Vic Roberts
http://www.RobertsResearchInc.com
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| ... |
| Posted: Mon Jun 23, 2008 6:01 am |
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Guest
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Quote: They aren't really rated in years -- they are rated in hours used.
If you look at the packaging (at least in the UK), you will find
the assumptions used to work that out, which are probably 3 hours
use per day. If you use them 9 hours a day, then you'll only get
1/3rd of the 7 years.
Yeah, I realize the lifetime ratings are dependent on actual use, and
that's why I was comparing them to the lifetime of the incandesent
bulbs we use (often in the same fixture). Too bad we didn't actually
keep track of the lifetimes and could actually compare them to the
incandesents with real data. I keep wondering if it's just a
perception thing on our part. |
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