Chimney length and creosote buildup. Longer pipe = more creosote?

[voland]

Im in the process of building a new home and will have a wood stove installed. The room that its going into will have 20 foot celling over where the stove sits. I expect that the total height of the pipe to likely be close to 40 feet... My concern is that due to the length of the pipe and the cooling of the gases towards the top of the chimney, I will have a lot of creosote buildup.

I understand that I can lessen this by burning dry wood and burning hotter fires, which I would do, but how much worse is this going to be vs say a 25 foot chimney? I might have a way to route it at a bit of an angle to make it shorter... Anything else I can do to help prevent this?

Thanks in advance!

 

[kborndale]

Use double wall pipe in the living area and switch to class A when you hit the ceiling and you will be fine. With 40 feet you will probably need a key damper or two for excessive draft.

 

[bholler]

Im in the process of building a new home and will have a wood stove installed. The room that its going into will have 20 foot celling over where the stove sits. I expect that the total height of the pipe to likely be close to 40 feet... My concern is that due to the length of the pipe and the cooling of the gases towards the top of the chimney, I will have a lot of creosote buildup.

I understand that I can lessen this by burning dry wood and burning hotter fires, which I would do, but how much worse is this going to be vs say a 25 foot chimney? I might have a way to route it at a bit of an angle to make it shorter... Anything else I can do to help prevent this?

Thanks in advance!

How would angling it make it shorter?

 

[voland]

How would angling it make it shorter?

yeah, looking at the proposed architecture, it actually wouldnt be any shorter. I was thinking of having it come out from the lower part of the roof but because it would need to go above the roof peak, it would end up being the same height anyway.

p.s. image is not representative of actual install. this was just an architect rendering... the pipe would be installed to correct height, distance, etc...

 

[voland]

Use double wall pipe in the living area and switch to class A when you hit the ceiling and you will be fine. With 40 feet you will probably need a key damper or two for excessive draft.

Thanks! Why would I need two key dampers? Wouldnt one do the job?

 

[moresnow]

Using the given dimension, It appears as if the roof top height from first floor to peak will be around 25 ish?
Unless I am missing something 40 doesn't really fit?

 

[voland]

Using the given dimension, It appears as if the roof top height from first floor to peak will be around 25 ish?
Unless I am missing something 40 doesn't really fit?

Heh, I dint read the dimensions right... Looks like 25 feet is going to be about right... Maybe im worried about nothing... I guess 25 is about average?

 

[kborndale]

Thanks! Why would I need two key dampers? Wouldnt one do the job?

Depends on the stove, some easy breathing stoves will still run away with 40' and one damper, especially on really cold days.

 

[voland]

Depends on the stove, some easy breathing stoves will still run away with 40' and one damper, especially on really cold days.

Im sorry if I am being thick and not getting it... My understanding, and its probably wrong, I should be able to control the airflow from 5%(allowing for some seepage) to 99%(wide open). What would the second air damper do?

If its 99% closed, would the long chimney still pull too much air requiring to... section off the air flow so break up the draft?

 

[bholler]

Im sorry if I am being thick and not getting it... My understanding, and its probably wrong, I should be able to control the airflow from 5%(allowing for some seepage) to 99%(wide open). What would the second air damper do?

If its 99% closed, would the long chimney still pull too much air requiring to... section off the air flow so break up the draft?

Yes if you actually did have 40' you would most likely need more restriction than the stoves air control and one damper could provide due to the drastically over spec draft strength.

But at 25' the stove might do it on its own especially with your higher temps in Texas. At worst you would need a single pipe damper

 

[voland]

Yes if you actually did have 40' you would most likely need more restriction than the stoves air control and one damper could provide due to the drastically over spec draft strength.

But at 25' the stove might do it on its own especially with your higher temps in Texas. At worst you would need a single pipe damper

Thank you for clearing that up! Ill ask them to install a single damper just in case...