Time to poke the bear????
I rate my handfed at 70% burning pea coal. It's sticker rated at 50K which gives me an output of somewhere around 35K flat out. My house is 985 sq ft with newer windows, no wall insulation but the curtains don't move with a 25 knot wind blowing from the north east when it's 5 outside.
Using 40 BTU per sq ft I get a required BTU of 39K which explains why when it gets stupid cold out and I'm running my vig at 650 on the griddle, the oil boiler for the baseboard heat kicks on. I will burn about 60 lbs a day so if it's rated at 12,500 btu per lb then that comes to 31,250 BTU/HR. Numbers are not to far off are they? On really cold stupid cold days I will burn two hods a day or about 80 lbs. That puts me at about 41K but that is the far outside exception and I'm watching that vig closely and monitoring with the infrared gun
Oh yeah when it gets like that we hang a flowered fabric shower curtain across the kitchen doorway. Kitchen gets to about 60 but then I don't care because we aren't living in the kitchen. I set the oil boiler thermostat in the kitchen for 55. That's only for a few days a winter though.
I really have no opinion about efficiencies, heat transfer ratio's, round pot, square pot, rectangular pot, lined, pot unlined pot, BB, antique, modern, heat tubes, no heat tubes, blower, no blower. They are nice intelectual gymnastics but the only one tried and true test of a heating system is.....
Does it keep Momma warm and happy?
Because if Momma's Happy, I'm estatic