I am considering installing a pellet stove (Enviro Mini or Jamestown) to go along with my wood stove. Is there a maximum vertical length that a pellet stoves flue can be? The stove would be in a room with high ceilings (around 14ft). The total vertical run, including outside would be roughly 20ft. Is this too long for a pellet stove flue? The majority of the run would be indoors (is black stovepipe acceptable for the indoor portion?) Thanks.