Don Klipstein wrote:

In article ,
wrote:

Has anyone noticed that Compact Florescent bulbs burn out at the same
time? The first time I thought it was a coincidense, but it just
happened again. The last time I had 2 of them in a kitchen ceiling
fixture. I installed both at the same time, same fixture, on the same
switch. One bulb burned out, a few days later the other one did.
(these were the ones that stick straight out of the base)

The explanation may be heat. A significant heatwave has
made the national news a little bit. Integral-ballast compact
fluorescents, especially 15 watts or more, often have problems with
ceiling fixtures and small enclosed fixtures and downlights. Philips SLS
non-dimmable versions up to 20 watts are better, and their 23 watt
non-dimmable version is also rated for use in recessed ceiling downlights.

Compact fluorescents do not take heat as well as incandescents, and
produce more non-radiant heat than incandescents of same wattage (but at
least normally less than incandescents of same light output). Compact
fluorescents produce little infrared, so almost all energy failing to
become visible light becomes heat in the fixture as opposed to a fair
amount materializing in the same room but outside the fixture.

Now, it's the bathroom. The bathroom has one switch that controls two
identical wall mounted fixtures on each side of the mirror. About 10
days ago I turned on the bathroom lights and one of the CF bulbs went
up in smoke (literally). There was a shower of sparks in the base of
the bulb, and a puff of smoke, which ended the bulb. I replaced that
one with a standard bulb. Today I went in the bathroom, flipped on
the lights and the other CF bulb started flashing on an off and
seconds later it got real dim and then died. (these were the twisted
type, and both were installed at the same time).

This is more than coincidense.

Maybe heat, maybe a line voltage surge from lightning damaging but not
outright killing the bulbs (line voltage surge damage is more often but
not necessarily either immediately fatal or negligible-zero).

Note: There is nothing wrong with the wiring, switch or fixtures.

I am going back to standard bulbs though. The CF bulbs do not have
anywhere near the life they state, in fact standard bulbs seem to last
much longer. For the price of these CF bulbs and their short lives, I
dont think I am saving any money. Sure they use about 60% less power,
but they cost ten times as much as regular bulbs. Besides that, after
watching that one go up in smoke, I think they are a fire hazzard.

I now see not-too-bad compact fluorescent bulbs for about $4-$5 apiece,
great ones for about $8, and frequent promotional specials at home centers
for ones at least "fair" amounting to $2 per bulb or less.

Power savings are more typically 65-70%, in good cases 75%.

Some compact fluorescents are bad and some situations do not call for
them:

* Dollar store compact fluorescents in my somewhat major experience are
lousy to outright rubbish. I buy them mainly to report on them.
Complaints are many, including color, light output, light output in
comparison to claims of light output, and a high rate of scary early
failures.

* I have seen a bad run or two of 25 watt spirals, of both GE and Lights
of America brands.

* Lights of America is a brand where I have had a disproportionate share
of early failures and other disappointments, although their spirals made
after 2001 may be as good as other brands of spirals.

* Compact fluorescents, especially of higher wattages and/or other than
non-dimmable Philips SLS types up to 23 watts, often do not do well in
small enclosed fixtures and downlights due to heat buildup.
Most commercial/institutional buildings with compact fluorescent ceiling
fixtures have different bulbs that do not include ballasts, and the
ballasts are located in the fixture usually out of view.

* Fluorescents in general, and especially ones smaller and of lower
wattage than 4-footers, tend to be uneconomical when on-time is short.
Low duty cycle makes payback of energy savings longer, and frequent
starts cause extra wear. Rated life is typically specified by the
manufacturer to be typically achieved with 3 hours average runtime per
start. I generally do not recommend compact fluorescents for motion
sensor lights, closet lights, refrigerator lights, nor for bathroom lights
that are mostly used for short trips.

Some more details in:

http://www.misty.com/~don/cfx.html

- Don Klipstein )

Thanks for the info

Lou