The Eagle Husky is primarily designed to burn wood - coal fire boxes are typically taller and narrower. However, I have burned coal successfully. The advantage of coal is a longer burn, more than 12 hours instead of 4-5 with wood. The disadvantage is a much greater volume of ash to be removed, 20 times more than wood, and it's toxic - you can't throw it on the garden. So you must have a place to get rid of large amounts of coal ash.
My procedure is as follows. Fill the fire box with a full 50 lb sack of nut coal and spread evenly. Now place a few pieces of wood on top of that. Use the oil burner just long enough to light up the wood, which in turn will light up the coal as it burns down. (Lighting a coal fire from the top is actually the correct way.)
That's all - easy and reliable to light a coal fire this way.
About cost: In my area, wood (cut split and delivered) is about $200/cord and nut coal is about $320/ton. At these prices, the cost of burning wood and coal are roughly comparable.
Questions:
It is not clear if the secondary burn air inlet (the rotating disk) should be open or closed for coal.
I have read that burning of both oil and coal in the same flue creates strange chemistry in the creosote, but my flue does not accumulate much creosote in any case, so I have not confirmed this.
