Often wondered about these. I called these folks last year before I bought. One of their employees wants an AA to medal with to make a hybrid AA and P&M for himself. Price is way out of orbit, probably have to circulate the water 24/7, and have plate heat exchangers. It probably does work, but living this close to anthracite and Williamsport, plus folks digging used AA's out of there basements once in a while, made it a no brainier. Really happy with the axeman. It must be efficient because I still have a few dollars in my wallet and my wife isnt bitching at me for being cold.
I do like the ash remover.
Made me think about making something to do the task. Thought about the chained conveyors in concrete trough like old milk barns had to drag cow crap out. Never did it though. And now thinking about it, they go with a screw auger, it might help prevent cold air from blowing right into the unit.
No crap chains for me