I have a Harman accentra insert with a zero clearance box. The back of the box is in my garage. I have a 3 inch exhaust pipe going up through the roof of the garage. My thought is to remove the exhaust pipe and Attach the Selkirk exhaust pipe and add the oak to that. I think thats the name of the pipe where you can attach it this way I dont have 2 pipes going through the roof plus i can have the benefit of heating up the air before going into the stove. What do you think.