New to Forum . . . I recently purchased a Majestic Royal Superhearth 48" and will be installing in my soon-to-be-built cathedral ceilinged livingroom. I'm remodeling the entire house (90% gut job) with 2X6 new walls for the addition(s). Probably using Icynene in walls and rafter systems and envelope will be pretty tight. I'm considering one or two OAKs (AK-MST) for this large box. I see that OAK discussions have been all over the place . . .but am wondering if there is much of a difference when considering an OAK for a large-opening fireplace vs. for a wood burning stove. Also, having a little difficulty finding 11" double-wall venting for the unit. Any help would be GRATEly appreciated.