Compact Flourescent Lights & Soot

Would someone knowledgeable person please explain why soot in the air settles in a cone shape pattern above our wall lights and on the
ceiling? One argument is that compact flourescent tubes give off some negative ions that causes the soot that is in the air to settle while the other agrument is that the compact flourescent tubes give off smoke especially when they are failing.
Any help appreciated, Thanks, Al
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I suspect it's from the air currents generated because of the heat of the lamp.
Cold air from below is heated and because of reduced density, rises. As it rises and spreads out, it cools and the velocity reduces to the point where any "soot" drops out of suspension.
But that's just a WAG.

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Spot on. Also, real soot is quite sticky. The effect was well known long before CFL's were invented.
If you are seeing this and you have any gas or other combustion appliances in the building, you should get them checked out. Production of soot and carbon monoxide go hand-in-hand, and you might have an appliance which is a) generating these as a result of faulty combusion, and b) releasing the combusion products into the building.
If you are in a poluted urban area, the soot may simply be from engines and industry.
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Andrew Gabriel
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On Fri, 9 Oct 2009 09:24:48 +0000 (UTC), snipped-for-privacy@cucumber.demon.co.uk (Andrew Gabriel) wrote:

Thanks for the reponse. I think that is what is happening here, we live next to a truck route intersection and the soot from the diesel engines idling at the stop is the cause. I've been banging my head against the wall telling them that the cheap fibre glass furnance filters do not stop soot.
Al
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Alfred Kaufmann wrote:

When I lived in an apartment downtown next to a busy street I had this same problem. Not with CFLs, because they weren't in common use then, but the black soot from Diesel exhaust collected on things. Top of the refrigerator, inside the computer, above the baseboard heaters, wherever air was flowing.
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