I've been searching through the posts here to find some information on "mid-sized" coal furnaces. I have a 20,000 sq ft warehouse in Portland ME that is costing me a fortune to heat with natural gas. Looking online I have found tons of hits for house sized coal furnaces, and quite a few for massive industrial boilers, but I'm having trouble finding information on mid-sized coal furnaces. Does anyone have any suggestions as to manufacturers that serve this niche market? Thanks in advance.