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a theoretical chimney question

geordief · 2009-05-12 19:24:19

I know that hot air drives the updraft but if the fire is not lit is there a natural movement of air up the flue? As long as the room is not airtight will there be a nutural updraft -and will it increase as the air outside above the chimney becomes windier?

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12-05-2009 8:24pm

#1

geordief

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I know that hot air drives the updraft but if the fire is not lit is there a natural movement of air up the flue? As long as the room is not airtight will there be a nutural updraft -and will it increase as the air outside above the chimney becomes windier?

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#2 12-05-2009 11:36pm
fmcc

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Geordie as long as the air in the room is hoter than the air outside it will rise up and create a draught fire on or not. It will also depend on the amount of fresh air into the room. Wind will increase the effect afaik but not as much as a hotter fire will.

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#3 15-05-2009 8:59am
anon1

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If hot air meets a cold chimney can condensation form and flow down the chimney?

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#4 15-05-2009 9:51am
demanufactured

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That would only happen if you had a smouldering fire going te whole time , say in a stove or ranger where you have the fire dampened down.

In an open fire once you have a good fire going it couldnt happen because 80% of the heat goes up the chimney.

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