I heat my shop with coal,960sq.ft.10 ft to the trusses,I am paying 200 a ton for antracite(sp?) coal,I get it from the Omish folk usally,3 ton will do it.
I know that does not answer your question,but I thought I should comment.
I start the season with small wood fires,then when the cold settles in the coal comes out,coal heat last (in my stove)for over 18 hours,so in the morning it is toasty just like I left it.
I belong to a coal forum ,it is call antracite somthing?but there are bituminous burners on there as well,if you search with proper spelling you will get data than you need,them boys and girls think of thier burners like we think of our machines,yep.
Off topic abit,but just yesterday the propane company came and took my 500 gallon tank and left me a 250 gallon tank,said i have been burning less than 300 gallons a year,they gave me no choice,i heat the house with wood,have for 30 years.
Buzzsaw on the back of the new holland,and being a shop rat,you all can imagine just what my splitter looks like,eh?
GW