will try two 45's first and if no change i'll trygoing the other route.this was my 1st stove and i guess to it seemed to run good with no issues till now.i'm pumped to get new one up and running. with this new wealth of knowledge i'll be sweatin my butt off.all this info is very much appreciated.before i retire ,on the simpson duravent,does it onl only come in 1ft increments or can i get an 18' length.that would help me push T 6' more away from the house helping me clear soffit.this way i can just go vertical right up past roof line