gerryger said:
If you could elaborate about the specifics of the condensation problem....are you talking about condensation forming on the flex duct or condensation affecting the burn pot/combustion process.
Since I took the dealer's advice and didn't get the OAK, and since he was doing more of a shaking his head and mumbling "We've had a lot of problems with that ... condensation" than giving specifics, I don't know. What I'd be concerned about isn't the duct itself, but whether it would lead to rust in the back of the stove in the area where it would connect in.
It could be that the dealer just didn't figure they could charge much more for the installation by including an OAK, and only muttered about problems because it wasn't a money-maker to sell me one. But he more gave the impression it led to more warranty service calls, and that that's what he was trying to avoid. I was surprised, since I've always believed in outside air for a fire. He was strongly against it. I assumed he knew something, and it was more problematic for pellet stoves. Maybe not. So I ask if anyone's seen such problems.
Ah, I see Smokey says "Yes, any way for moist air to get into the plumbing will allow rust to take place during the off season." Is it only an off-season concern then? What about when the stove's on a set back thermostat and is mostly off overnight?