Hello, I'm a newb in this forum, go ahead and scold me all you want, but I heard that this is the best place to go for wood stove questions. I've tried searching around but couldn't find any info in the forum. After replacing my gas furnace with a hydronic furnace connected to a tankless water heater, I'm left with double-walled direct vent pipe going through two floors to the roof. I have been throwing around the idea of re-purposing this to an extra air intake source for the furnace OR using the pipe for a standing wood stove in a 500 sqft room. I didn't include the wet (mechanical) room to be supplied by the furnace so it can get cold in the night. In addition, I love natural fires, and thinking about making the space into an office. QUESTION: Can I use the double-wall gas exhaust pipe as my chimney pipe? I assume no, as I have read elsewhere because of temperature ratings. In which case, can replace the pipe and run stove pipe through floors? I assume no, since I read an article on Hearth.com here. Basically, Can I do what I want and re-use the existing holes in my house to allow heat and smoke to go through them with using a free-standing wood stove? Even a possibility? I'm sure this has been done before. Thanks a bunch, I think the answer is just NO. But I figured I'd ask some experts. I'm sure I'm not the first to ask nor the last so maybe this will help someone else too.