I ran into a good deal at Lowes on UL 103ht chimney pipe, I Bought 12' for $210. The question is can I run all ul 103 chimney pipe from stove clean through to the cap. Using 6' inside and 6' outside. I wasn't sure if it could overfire or would have significant heat loss compared to using single wall in the house, Or if it could actually help draft better being that I am only going to have a 12' run. any advice would be great. I can take back the pipe and get single wall.