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[jamesbodeis]

Was a little bored out deer hunting tonight and started wondering what effect chimney length has on a natural draft stove.

[BoilerHouse]

Definitely an effect.  Higher stack equals greater draft. 

[Pinehouse4]

I agree, that has been my experience using wood stoves for 35 years provided of course the diameter matches the stove.

Meaning you wood not put a 6 inch pipe from a stove into a 12 x 12 flue, you may think it better but it is not.

Bob

[jamesbodeis]

Is there then a point of diminishing returns? Too much draft?

[BoilerHouse]

Too much draft could be a bad thing. First the expense and bother of installing and maintaining extra lengths of chimney pipe.  Then, I would think that either you would run with the damper partly closed, or the fire would burn hard and fast and carry a lot of heat up the stack.

[Pinehouse4]

If it were an air tight stove then in theory you regulate the air that can be sucked up the chimney. It will ideally suck up whatever you choose to give it.

I see no point in adding length beyond what is needed ( although my wife may disagree ) 

Bob

[jamesbodeis]

All makes sense. I just wondered if additional stack would help the fire get going quicker. I put three feet on a bit ago and it seemed like the recovery time improved. I've noticed during the drive hunting a lot of stoves with tall chimneys and it got me thinking.

[MattyNH]

Not quite sure why a high stack is a bad thing.. As said on here.. A higher stack with a air draft boiler means a quicker ignition of the fire instead of smoking.. Quicker recovery time .. Dampers and all that is bs your not gonna draw air unless you got a air leak somewhere.. I'm 19ft up with forced air draft.. No affect on my end... If you thinking of going higher go for it.. So much better

[slimjim]

And watch your stack temps as well as wood consumption rise!

[jamesbodeis]

I can see where wood consumption could increase and understand that part. Being new to all this I don't know the importance of stack temps. Could you explain it to me?

[Jwood]

Higher stack temps just means the heat is not being absorbed through to your water jacket, higher stack temp equal more wasted heat think of it like a forced air furnace 80% efficient you must have class b venting due to the high vent temps 96% efficient you use PVC and the vents only get luke warm hope that helps

[jamesbodeis]

I see what your saying. Thanks.

[MattyNH]

And watch your stack temps as well as wood consumption rise!

There is no extreme like a wow.. Buddy of mine has the same boiler as me with no stack.. Pretty much burn the same.. We both have 1800sq foot homes

[slimjim]

Have you ever actually measured your stack temp?

[MattyNH]

Have you ever actually measured your stack temp?

No I haven't