This is my four year firing a Mark II. This is what I learned to insure the longest, least expensive burn. Thank you members of the Forum.
First, if you don't have a barro, get one. That made the most difference in reducing my coal usage and retaining the heat for home use instead of losing it up the chimney. I don't really understand it but I'm willing to believe it works because I've seen a drastic reduction in my coal usage. Before anyone writes me to fully explain how the barro works, thanks but I don't care - I just believe. I feel the same way about knowing why you can’t divide by zero and most other mathematical questions. Oh, and Santa Claus
Second, use pea coal for "smoldering" fires that produce heat over a long period of time. This type of fire will not have a lot of the "blue ladies" dancing but it will last a long time and put out a lot of heat without attention or minimal attention. Do you have a thermometer on the stove front or top? If not, you need one to properly control your heat production.
Right now - 65* outside - with the stove idling, as long as I maintain a stove top temperature of 150* I know I have a fire no matter what it looks like (it looks pretty dead.) Remember, coal burns from the bottom up and can burn a long time without any actual flame. Sometimes I can only see a glimpse of red coals deep in the bed but as long as the stove is 150* I know my house will be 79 degrees. (Yes, that's warm but we need the heat at night. We open a window during mid day.) The air intake is adjusted to provide this temperature; too little air, no fire, to much air, too much fire i.e. wasting coal. Right now, to reach my perfect balance I have my Mark II air valve at 1/2 turn open. That will change as the outside temperature gets colder and I need more heat. Then I have to find a new perfect balance. That’s the art of burning coal in a hand fired stove.
The after barro temp on the chimney connector pipe should be about 100* less then the stove front or top. If its not you are losing heat up the chimney.
The pea coal will not need to be shaken as often nor as vigorously; it’s just something about pea coal. Some unburned pea coal will slip out of the grate along with the ash if you shake too hard. If you are shaking it just right you will have "crumbly" ash, not a powder but crumbles. With this type of pea coal "smoldering" fire you should only have to gently shake it once a day, if that.
The hardest part of burning a “smoldering” fire is trusting that the coal will do its thing. It looks dead but there is a fire. True story; last winter I had a 36 hour burn when we went away for the weekend. The house was the same temperature when we got back as when we left and there was only one ash pan of ashes to empty. A quick refresh and it was good to go.
A 24 hour burn without shaking is possible but you have to believe first; trust the thermometer - find your perfect balance between air and temperature. If you have any questions, ask! Someone in the Forum will have the answer or can find it fast.
Good luck, Lisa