I just bought the pellet stove and having trouble with getting outside air . It is against a chimney in the center of the house I am going to run 3" pipe up to chimney opening then two elbows to 4" flex 20 feet to top of chimney then out about 10 inches above top. I have a 10 inch by 10" main beam under the floor where I was going to drill a hole to get into the basement to run the fresh air intake . So my thought is to drill a four inch hole in the same flue below the exhaust to pull outside air . My friend said I could get a condensation problem or pull exhaust fumes down . Is it possible to pull fumes down 20 feet , and does this sound like a bad idea . PLEASE HELP BEFORE MY WIFE KILLS ME !! THANKS CHRIS