Dave/Matt,

Could you review the procedures used to establish the btuh output for the WL110? I'm back calculating my heat loss, and would like to figure out how I'm going to go about squeezing more efficiency out of this system.

I recall that with coal this unit operates at 90% or so efficiency, what outlet temp is that based on? Does the efficiency change based on outlet temp? Is the calculation used factoring in the ash content (averaged) for the coal, or is that an additional loss that has to be calculated?

Is the stoker motor at max feed rate the max btuh? Or is there some kentucky windage built into it to account for different quality of coal (which I would expect)?

And some general questions for the board, when getting BTUH ratings for radiators which are based on water temperature, is that generally considered the temp of the water leaving the boiler or reaching the radiator? Any guides to what the heat loss per foot of pex would be?