Sunday, October 12, 2014

When Flourescent Lights Go Bad

Fluorescent lights produce a lot of light for little power.  My kitchen lights, which use two T9 bulbs, are rated at 32W, 2400lm and 22W, 1400lm1.  The bulbs are expensive and not easy to find, but they supposedly last five years.

The problem is that the performance and longevity of fluorescent lights depends on the ballast.  This is an electrical module that conditions the current, and it's not 100% efficient.  Also the ballast will degrade and eventually need to be replaced.  Sometimes a faulty ballast makes itself evident when the light flickers, or when the light doesn't turn on immediately and you need to flip the light switch off and on to get it to light.  At this point the bulbs will burn out quickly.

The ballast is even more expensive and harder to find than the bulbs.  And replacing the ballast isn't meant to be done by the consumer, although a home owner who can replace a light switch or electrical outlet will be able to replace a ballast in about ten minutes if the fixture is designed well.

I mention all this because I again find it necessary to replace the ballasts in the two kitchen lights.  In fact, I was thinking of replacing these fixtures with new fixtures that have multiple sockets for standard (Edison screw) bulbs.  I figured this was a better long-range solution because it would allow me to use Compact Fluorescent Bulbs today and then eventually graduate to LED bulbs.  Never again would I need to search for the expensive ballasts and replace them.

But I did manage to find the ballasts for quite a reasonable price.  So it didn't make sense to replace them this time.  But in ten years, if I'm still in this house, I think I'll be buying new fixtures.


1 For a comparison of the lighting efficiency of various types of bulbs, please see https://en.wikipedia.org/wiki/Luminous_efficacy#Lighting_efficiency.

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