I am about to put a 602 in a single room outbuilding. It is 180 square feet, well insulated and quite tight. a few questions: 1) chimney height will probably be about 13 ft from stove top to chimey top, six of which will be class-A. will this be enough for good draft? 2) I am concerned that the building may be too tight for adequate airflow. thoughts on this? If so, any suggestions for make-up air? the 602 doesn't seem to have an outside air kit option that I could find. 3) I am thinking of rear venting it. If I do this I will use double-wall pipe. do people out there have such a set-up? Does it still draft well? or does rear venting compromise draft?