Dark stains around the house

Hi, My sister is currently living in a home and has noticed dark stains appearing on many of the ceilings/wall (particularly at the interface).
The house is heated by forced hot water. The furnace burns natural gas. It is a 1 level house. Some candles are burned (tea lights, scented candles). She states that maybe twice a week she uses candles but for a relatively short amount of time.
Many of the stains are in rooms that do not have candles burning.
Please help,
David Walker
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http://pages.cthome.net/edhome
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It's called sooting or streaking. With all due respect to Sis, she probably is burning cheap imported candles from China.
I am looking for the report I had on it and will post it as soon as I find it.

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FOUND IT!
Sorry about the yelling.
It's called Ghosting. Here's the link. http://www.homeenergy.org/archive/hem.dis.anl.gov/eehem/98/980109.html

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Tom Baker

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snipped-for-privacy@nycap.rr.com (DaveWalker) wrote in message

http://hvac-talk.com/vbb/showthread.php?threadidG285
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