Last night, I cut the air to cruise setting in the dark, and set it a little too low; When I re-loaded I still had one intact but coaled split, and one that had broken into chunks. With the air set too low, room temp had dropped to 65. House is a little under 1000 sq.ft. total and we have the 250 sq.ft. mudroom/bedroom door closed to about 6" so it stays 5-7* cooler than the main room. The log structure has no wall insulation, just 1" of wallboard, and the house needs a good bit more air-sealing. It's probably like heating 1500 sq.ft. in an average house here, but that's a guess..
I couldn't jam the box with the coals still in there. Pic isn't great but I didn't want to open the door. Maybe I'll post another run at some point with the haze cleaned off the glass so I can get better pics.
I was able to load two decent Black Locust splits and one Red Oak, maybe 3/4 of a full load. Fire box I've measured at about 1.4 cu.ft. usable..andirons keep the wood back a little, reducing the fire box size slightly from what the maker states.
I ran the new load with the air set 1/4 open with a little flame, for about an hour. Then I cut the air to cruise, a bit above minimum, slightly above 1/8 open.
Starting OAT was 23*. Afternoon temp got up to 34 or so. Wind about 10 mph all day. Stove temp crested around 525.
At about 8 hrs. I had a couple of intact coaling splits left. STT was around 300, room temp 70. I upped the air to about 1/4 open. A couple of small, thin, barely visible blue flames began coming off the coaling splits. Temp went back up to 330, then back to 300 over a period of three hours.
So at 11 hrs. this is what's left in the stove. Hard to see the size of the chunks, but you can see the back of one that is close to the door, lower left. The others in the background are similar. I'd subtract an hour or two off the effective heat time if the load was all Red Oak, a medium-high output fuel. If it was warmer out, I could have cut the burn rate down a little further and added a couple hours. Black Locust raises peak stove temp a little bit and burning down BL coals yields a little more stove temp as well. I probably won't load for a couple more hours since it's 71 in here. Headed to the teens tonight but the wind is slacking off..
My firebox is only about 1 sq ft., Jotul 3cb.
Gotta be bigger than
that, doesn't it?
Did you ever measure actual usable space? Stove makers sometimes list inaccurate volumes.
Oh lawd that pic kills me! Here in softwood country after 8 hrs I wake up to just a couple small coals left In a bigger stove...
Yep, hardwoods produce a bunch of coals will last a good while and keep pumping heat. But if you need max heat, the coals get in the way of another full load, and must be dealt with. There's a 1/4" hole that they put in the back of the Keystone ash pan housing, which admits a little air. If I run a poker along the back of the fire box floor, ashes will fall through the grate in that area and the ash pan air will enter back there and eventually bore a hole through the coaling back splits, resulting in a hollow "coal cave" of glowing coals about the size of a cantaloupe.
This thread shows the value of having the stove make and model in the signature line.
This thread, and just about every other one where someone is asking questions of "stove temp, burn time, loading my stove, smoke roll-out," and on and on.....and on
forever! It's usually a case of TLI..Too Little Information.