I'm curious as to how you think it may not be optimal for burning wood? Are you thinking bigger? Insulated clay liner, insulated metal liner, bigger, etc.?
Honestly Larry, at this point it seems like my chimney is doing just fine. I was just wanting to try what I could to see if I could improve the draft which might enable me to run my stove at an even lower temperature in above 50F+ weather.
As Steve said though, I'm seeing the difference between what a coal stove needs and what a wood stove will need. It's almost for burning coal that there may be a point of no return...err...um...a point where adding height may not improve the draft but rather may impede it. I don't know. Does that make any sense? Seems if a chimney is too large it may draft up to a given height but past that the chimney could remain too cold? See what I'm thinking? I have no idea if I am wrong and I could be way off.
Burning wood, then I can see where adding more height may indeed be more beneficial because exhaust temps are so much higher. The tricky part for me is finding the middle ground for either fuel.
In the past, with an older pre-epa stove there was some smoke roll back into the room even when the chimney was hot. However, that could have simply been cause by a faulty smoke deflector and is why I removed the stove for repairs and to try coal.
Of course, to repair my broken liners, adding two more additional feet shouldn't hurt anything. I have a few choices. I can tear it out and re-line with clay myself which is the cheapest way possible to repair this chimney or, I can reline with metal, or I can add 2-4 feet and leave the cracked liners in place and have the chimney coated with Heatshield to fill all gaps and cracks and which also insulates it.
