Longest I ever got when making an attempt was 37 hours, from cold stove start and ending at ~100 degree stove top.. was on 47.6lbs Scots pine.
BK claims 30 hours on 40lbs of softwood in the Chinook... I say their specs are correct.
Outside temps varied from ~30 in the day to ~20 at night. House stayed 74 during the day and dropped to 70 at in the morning, then rose back up slightly as noon time came before the fire died down.
792sq/ft home... Fans were on at the time.
If Fans are off, the house temp will be slightly lower. When it's 40-50 out I burn overnights using no fans, that way the house will stay about 72-74 and not overheat the place.
haven't tried doing a long burn with fans off.
I wouldn't normally expect to load up that much wood at one time. I dry fit every piece to make it as tight as I could, remembered how everything went in there, weighed it all, then crammed it back in. My pine splits are MAYBE 3" at most. 2" is more realistic. I don't have large splits of pine. I split all my pine before I bought my splitter, so I used a fiskars and turned all my pine in to tiny bits and pieces. So if anyone tells you that small splits of pine or anything will overheat a BK stove, they're full of trash. Same thing goes will pallet wood. I use a bunch of pallet wood, what I've got has been seasoned for over a year and is dry as can be. I'll stuff the stove as much as I can, and it's incredibly controllable and doesn't even seem to have a hint of wanting to overheat.
Generally my burn cycle is as follows... I'm working 12-14 hour days right now. So what I do, is when I get home I'll load the stove full of my cottonwood/willow/catalpa mix (yes, It's 10 degrees out and I'm still burning my softwood!!). I don't worry about packing it tight, I just throw some splits in there and whatever I can get in I get in. I do my usual char and turn it down... Then in the morning, I'll fill it with pallet wood. Usually not full again either... Usually Oak 1x4s and 4x4s. I'll just toss them in loosely, let it char... turn it down, and go to work. When I get home, there's usually plenty of wood left. Before I go to bed I repeat with throwing some softwood garbage on top, and so on. So I load twice a day, but realistically I could do it once.
I use pallet wood in the morning because I'm half awake, and pallet wood is all dimensional so it's VERY easy compared to my cordwood to get in the stove. All my softwood came from scrounges, so a lot of it is all knotty/twisted crotchy pieces... Which is part of the reason for I'm doing the cycle that I am lol
If I had cords of straight cordwood, I'd probably load once a day.
My pine is straight... and I've only got maybe 1/3 of a cord left.... so I save that for testing.