i dont know the technical terms for output, but this is how ours works...
i live in a static caravan, early 80's (not much insulation).
i use pine off cuts (free in one ton bags for the collection

) i sort that into kindling and bigger bits.
this stuff burns hotter than nuclear i swear.
once the fire is burning well i use elm. there are so many dead elms that can be had for the asking round here, and they dont need to be stored.
i spent all last winter indoors in a bikini it was that hot
a really good sized elm log or a scant shovel of coal and the burner closed down will tick over all night, then a good load of pine the next morning and we start again.
i cook everything and heat all my water of my little burner

if you use elm wood, when you come to split it, use a proper splitting axe and turn your rounds upside down so you split with the growth direction not against it. it truly is a bugger to split otherwise
