Many of you may remember the problems that we were having with our Oslo (
https://www.hearth.com/econtent/index.php/forums/viewthread/63944/,
https://www.hearth.com/econtent/index.php/forums/viewthread/54057/) mainly just an overall sluggish performance with the stove always feeling like it needed more air. We received TONS of helpful suggestions and advice on how to cure the problem, and that for that we are so thankful!
We tried just about everything, and in the end we sold the Oslo and replaced it with a Quadrafire Isle Royale which we absolutely love!!
After trying many things to get out Oslo working correctly, several people suggested that given the low usage on our stove, our chimney setup, and the vast majority of people who are very, very happy with their Oslo that perhaps we somehow got a "defective" stove that just wasn't working right. Frankly, I had begun to wonder the same thing but had a hard time getting my head around that as I had run a wire rod through all the air chambers so I knew that there were no blockages.
Well, I just got an email from the person who bought our Oslo, and he reports that the stove is working wonderfully for him! So, it would appear that the stove is not defective, but, as others surmised, the Oslo really needs a strong draft (especially here in the PNW with low barometric pressure and mild evening low temps) to work properly. While we had a 20' straight up shot of chimney/pipe and still had poor performance from our Oslo, the new owner has the stove installed in a ground level "great room" with 5' of single wall into a 90, then 28" of horizontal, another 90, and then straight up the gabled end of the house 31' to allow for all the correct clearances above the roof line, etc.
So, to me this confirms that at least for PNW conditions with lots of rain (and thus low barometric pressure) and average night time lows in the mid 30's to mid 40's, that an Oslo will probably only work well if you have 25+ feet of chimney.
NP