Hi, i just got an EarthStove model 901/905 and had a few questions. First off, it has a 1" or 1 1/4" pipe going up in the middle of the 7" chimney pipe. I heard that this is for when you shut the air down it pulls air so it can keep the pipe from getting creosete build pu or something, what my question is is how long does it need to be(how far up the pipe does it need to go?) The second thing is its mobile home approved so it has the 8" opening under the bottom of the stove but i dont live in a mobile so i wasnt even going to mess with that just let it pull air from the house. any info on the length would be wonderful thanks.