I have a NCB-250 coal unit.
Bit coal in large is high in sulfur. I use anthrocite, which is more expansive but much higher BTU and no smell at all.
I have 4500sqft new well insulated house, with DHW; last year that was the worst winter in 50 years, I used
2 cords of wood, and 5.5 ton anthracite to keep the house at 75F.
I used to heat with coal inside, it is very dirty. You will like the outdoor unit, but you need shaker grates and a boiler made for coal burning.
Sometimes, I just don't have time and energy to split and haul 10 cords of wood. If I burned wood alone, I don't think 10 cords would be enough for me.
5 ton for $325 is probably very high in sulfur. KY low sulfur coal is about $100-120 / ton. I pay about the same for anthracite, but it's a special deal. For $600 keeping 4500sqft at 75 for 6 months, with little splitting, is a good deal for me. I spend more on my wood trailer and chain saws, and my time on cutting wood. If I had more time, I'd cut more wood, but right now, I have less time and I rather use more coal so I don't have to worry if have enough seasoned wood.
I also do not have a large barn to hold 20 cords to season for this year and some for next year. I have a 12x10x6high coal bin that they just fill up - free delivery, and I don't even have to lift a shovel. I keep the 2 cords under a tarp, so it's easy for me.
Splitting 2-3 cords is enough workout for my back after years of doing it.
Wow, I always thought i was getting a good deal. I always heated with a hotblast indoor stove and one semi load lasted me all winter with usually a pickup load or so left over. So for $500 a year to hear my house was pretty good. Now I'm going to get a heatmaster owb, and I hear they can use 7-10 cords a year. I plan on using some coal but I don't know how well it will work yet or how much I can mix or how much wood it'll save me. It's bituminous coal, that's all I've been using this year is coal only, got 5 ton for $325 and no cutting or spilting. I'm having good luck with it although cleaning the soot and controlling the dust and smell inside sucks. I'm sure it'll be better outside then inside.