I had a local shop installer out to assess my basement for an install of a free standing Harman unit (maybe the 61 or 68, haven't decided yet) My basement is finished and below grade, so the topic of an OAK come up. The stove would be vertically vented up through the basement ceiling and then 90 out through the rim joist and up about a foot for termination. Since I have to run vertically I was told that I would have two vertical pipes visible if I added the OAK on the Harman, which aesthetically might be a total deal breaker. So not to beat a dead horse about the OAK, but can I get away with not having one? The installer says yes. It will only dry out the air in the basement, but pose no other issue with the function of the unit. I installed the 52i in my family room (upstairs) last fall and insisted on the OAK there for things I've read. Now I'm worried about doing this install without one. Doesn't Harman make a single vertical pipe that contains the OAK and vent for people that can't vent through the wall behind the stove!?