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Fireplaces Stoves

chimneys and coal
by: lobo posted: Saturday - January 10, 2009
can you use double wall stainless chimney pipe when 
you burn coal? can coal cause a chimney fire?

Chimney fires
by: Loui421452 posted: Sunday - January 11, 2009

A major source of chimney fires is burning the wrong 
kind of wood in the fireplace.  What happens is that 
tar in the wood is not completely consumed in the 
fire.  It is carried up the chimney in particulate 
form, then cools and collects on the chimney walls 
before it exits the top.  Over a period of time, the 
collection of tar becomes thick.  Then, at some 
point, perhaps during a very strong fire in the 
hearth, heat is carried up the chimney to the point 
where the collected tar ignites and you have a 
chimney fire.  For this reason, fireplace owners are 
very selective of the type of wood they burn in the 
fireplace.  Most choose woods with a low tar content 
to limit the possibility of a chimney fire.  They try 
to stay away from soft woods that tend to have a high 
tar content.

As far as the type of chimney - Tar usually needs 
somehting rough to collect on like the surface of a 
brick of the rough surface of a ceramic flue liner.  
The structure of the stainless steel chimney pipe 
promotes the collection of tar even though it has a 
smooth surface.  It is designed with a double wall 
where air flows between the walls to carry off the 
heat and keep heat off the exterior wall.  This cools 
the interior wall and causes any tar vapor to 
condense and collect on the wall.  Therefore, the 
collection of tar from the fire is more prominant 
inside stainless steel chimney pipe than in brick 
chimneis and ceramic flue pipes.

Now then, to answer your question.  Coal is produced 
by a reduction heat on wood where little oxygen is 
present.  The reduction process changes the tar and 
wood fiber to carbon.  When coal is consumed in a 
fire, there is no tar vapor or particulate matter 
given off.  Therefore, burning coal will not cause 
chimney fires regardless of what material the chimney 
is constructed from.

I hope this helps.  Good luck,
Louis Whistler

by: Loui421452 posted: Sunday - January 11, 2009
I misread the question as concerning charcoal.  Like 
wood, coal contains tar content.  In fact, because of 
the way coal was created (mostly with soft woods in a 
marshy environment), coal contains a lot of tar.

My assesment is that coal and stainless steel chimney 
pipes will NOT go well together.

I hope this helps.  Good luck,
Louis Whistler

thanks Louis...
by: BayStateHandyman posted: Sunday - January 11, 2009
I thought I was learning something about Coal, that I 
never knew...I didn't answer the question because I 
only knew about Coal and not enough about double 
walled pipe and then I was getting an updated lesson 
on Coal and I was glad I didn't attempt to answer the 
posters glad you read over your 
responses, like I always try to do...No harm no 
foul...Take care...Geno...

chimneys and coal
by: lobo posted: Sunday - January 11, 2009
louis whistler, I got 3 replies what is your answer?
If there is tar in wood and coal why do they make do 
they make double wall chimneys and what do they burn 
in the stove? Is there a chemical reaction that 
destroys the pipe? If you dont know tell me. I dont 
want to burn my house down. I dont know is a suitable 

by: davekoe posted: Sunday - January 11, 2009
I think you are perfectly safe if you are burning hard coal (anthracite) 
which contains very little hydrocarbons. Look in the yellow pages for 
chimney sweeps and call a few of them and you will know.

Be careful...
by: Ronbo posted: Monday - January 12, 2009
The chimney is not the main concern here.  What type 
of stove are you planning on burning this coal in?  If 
it is not an "air tight" appliance, DO NOT burn coal 
in it.  

I concur
by: Loui421452 posted: Monday - January 12, 2009

I apologize for the confussion.  I concur with the 
comments on athracite.  The way to prevent chimney 
fires is to use the proper fuel to limit the amount 
of tar produced that can stick to the walls.  Then, 
use the services of a chimney sweep periodically to 
clean the collected material out of the chimney.  It 
has little to do with the type of chimney you have.

There is no chemical reaction that will damage the 
pipe.  The pipe is designed to keep the OUTSIDE cool 
to make it safe for installations with wood.  

I think you are ok provided you properly manage what 
you burn in the fire.

I know some about coal, but my experience is with 
wood fuels.  I am from the South and we do not use 
coal down here.

I hope this helps.  Good luck,
Louis Whistler

Talk To Your Local Code Office.
by: Pahoehoe posted: Friday - January 16, 2009
Talk to your local code office.

All you received here was a lot of double-talk from 
people who have no idea what they are talking about.

Double walled "vents" are typically listed and labled 
only for medium heat appliances with "L" type used 
only for oil or gas appliances and "B" vents for Type 
I gas appliances.

Type "HT" factory built chimneys listed under UL 103 
is the only type metal factory-built chimney system 
allowed for use with high heat coal burning 
appliances in the US.

Otherwise you need to construct a masonry chimney for 
coal burning purposes.

Talk to your mechanical code inspector at your 
municipal building code office for specific and 
correct advice.

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