4. Not getting into %'s of efficiency, but once the draft is dialed in and and the coal is burning and settled in. I use about 29-30 lbs a day during winter.
Same BTU stove in a Keystoker, or Harman and I would be at 45-50 lbs to do the same job. Bigger grates on these has much do do with that as you MUST burn More at once with a square stove.
That's 34,800 to 36,000 BTU/day for one and
54,000 - 60,000 BTU per day for 2nd http://hyperphysics.phy-astr.gsu.edu/hb ... tloss.html
A sliver of info on house-loss BTU for southern house....
What would one expect for your house? Depends on many factors...but what would an ideal house BTU/day use be expected (for a given difference in outside v. inside temps)??? Anyone have idea?
Its very hard for me to get a real accurate number on the "R" value at my house. Its about 1,500 Sq ft. and 2 story built in 1862 ( Lincoln was President) It HAD no water or electricity when built and went 40+ years before those were installed. Some insulation blown in through clap boards 60 years ago has settled in the walls. I do have new windows.
That said, Its impossible to compare a Coal stove to a home heating furnace, and here is why. The BTU/day number is a 24/7 number as the Coal is ALWAYS on. An oil furnace has to play catch up, which gets difficult when it gets colder in an older house. The amount of BTU generated by Coal on paper usually does NOT equal what people "get out" of their stove. For example, IF you use a baro damper, you will suck heat out of your living space and Up the chimney...< If not, youll need to keep an Eye on your draft as winds and barometric pressure can affect usage.
Even with Coal Always on, it uses Less dollars than oil does, and can help dry out a damp house too.
Ideas are 20K BTU on days 20-40 degrees, and 45K on days 0-32 , and 65K on days -20-+10 For MY old house ....With Minimal Wind (<15 mph)
Right now I am in the 18-40 range