He's pretty sick in the head..he does this not out of need but for pure fun.
lol... best answer yet. I should put that in my sig line, with your permission.
I'll try to summarize several years (somewhat painful experience) in a few sentences. Yes, the house is a little on the large side by 18th century standards, not so much by today's McMansion standards, but about half of it is completely un-insulated mud-stacked stone. The windows and doors date to the 1773 expansion of the house, but I do have storm windows on the windows, so radiant loss is not all that bad but they are a little drafty (esp. the doors). Total area I'm heating is about 8100 sq.ft., but of that total, only 4500'ish square feet is being heated by wood (hence the high oil and electron use).
I do this work of felling, processing, and handling firewood under the guise of saving money, or at least that's how I sell the time investment to my wife, but I believe it has cost me at least as much in stoves and equipment as I have saved in heating oil. While it's a poor use of my time, if saving money were the sole goal, I believe it's good for the mind, body, and soul.
I run two stoves 24/7, and each is installed in a large cooking fireplace (see my avatar) on an exterior exposure wall. The first stoves were Jotul Firelights, and I found they were dumping a very high fraction of the heat they produce into the exterior masonry, by noticing that oil savings were not correlating to my efficiency-corrected wood BTU usage. I also have Flir thermal images showing the exterior stonework of my house being alarmingly hot, over large areas behind each stove. It was during this time, with these stoves, that I hit those 10 cords per year numbers, while my oil usage was simultaneously over 1200 gallons per year. I also noticed that the Jotuls did not have much effect on room temperature, no matter how hard or light I rode them.
So, I switched to the BK Ashfords, being a convective design. I immediately noticed they "feel" better in the house, as they have a much more noticeable effect on room temperature. Significantly, I can get very repeatable 36 hour burn times (I burn mostly oak), and have been able to mark settings on my dial for predictable 12 and 24 hour burns. Being worn out from pushing insane amounts of fuel thru those Jotuls, I've been treating the BK's differently, loading them full on a schedule that suits my work, and letting the oil burner pick up the slack.
I am looking forward to having comparative data, between the Firelights and the Ashfords in this house, but a few factors have confounded me. First, it was very cold the three years I was running the Jotuls, and it has been unusually warm the two years I've had the Ashfords. I'm scaling for HDD's, but there is still error in this for such different conditions (eg. imperfect choice of base temperature). Also, whereas I had expected my oil usage to go up a bit, since I'm burning maybe 40% less wood in the Ashfords, all the data I have so far indicates my oil usage is going DOWN (yes, that's scaled to an "average HDD year").
So, that's the story for the few who haven't heard it before. My highest oil usage, since firing up the first Jotul Firelight 12 is 2600 gallons in one year. My highest wood usage in a single year is somewhere over 10 and less than 11 cords, and I believe I burned 1200 gallons that particular winter. I believe my current usage will fall in somewhere over 6 but less than 8 cords, with 1000 gallons of oil per year.
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