On page 5 of the 30NC manual it states the clearances to combustibles as below: Side and Rear shields, single wall chimney connector: = 19-in Side and Rear shields, double wall connector: = 20-in My question is, why would a set up with DOUBLE wall require more side clearance that a setup with SINGLE wall? The stove body is the same either way, right?? -------------------- Also, I do not see listed any side clearances for a stove that has NO side heat shields. Mine has a rear shield only. Since the side shields are an OPTION, why wouldn't the manual notate the info for a standard unit that has no side shields? I would imagine the clearance should increase, (with no side shields) but by how much? Thanks!!