4" cap with hole is not a bad idea. I'll check that out. Thanks!
I've read the woodstove.org stuff. I don't think it necessary addresses very tightly sealed houses.
The connection is a "direct connection" but it is not intended to be an air tight connection. There are holes in the adapter that allow it to also pull air in through the room. It is basically just a connector that allows you to mount a pipe to the stove. And feeds the air where the stove would otherwise pull the air from the room. It is code here in new buildings, and it is being installed in a tight house with a balanced HRV, no clothes dryer exhaust (ventless).
So if you did not have any exhaust fans going, the wood stove would probably work great using room air.
If you had multiple bath fans and range fan going, I think you would not be able to get a proper draft going when starting a fire - they are something like 125CFM each (this is where I would just open a window), BUT the make up air is required for my energy certification, which I've worked hard to get, and this is the final requirement, so I'm going to follow through. I can always remove it later.
(I tried to get the certification without doing the supply air, because of all of the arguments against it... but it didn't slip by the energy guy).