The way I understand it Jerry is according to the vent connector sizing charts, all offsets begin with a 1 ft(12") rise.

As for the clearance, The 1" clearance is afforded by the double walled section of the B-vent. Therefore, any part of the vent including the single walled connector below the insulated portion and including the draft hood proper would carry a 6" clearance. Let's say you have a draft hood connector attached to B-vent and the distance from the insulated portion of the B-vent to the widest part of the draft hood where the air enters is 5". Then this 5" section carries a 6" clearance. However, once you reach that first roll in the Bvent, it drops to 1". So, from the opening inlet of the draft hood up about 5" I then measure 6" from there would mean the lowest combustibles could reach down a pipe towards the draft hood would be about 11-12". You have to remember this clearance is measured by swinging arcs so the single walled portion of the draft hood, which carries a 6" clearance is not measured perpendicular but tangential in all directions. This means the first 6" of so of the B-vent actually must be at a 6" clearanc for the single walled connector under it.
Is this confusing enough? Whew!
Bob

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