Wood stove, originally belonged to my folks in a 1600' home, no idea what btu. Shop is 24x36, heated area 24x24, walls r19 and the ceiling is 2" fiber glass. Ceiling insulation is original to building and should be upgraded, not sure I'm up to that much high ladder work anymore:laughing:. Pole Building with steel siding, prior to insulating the walls had a barrel stove, on a cold day (around 30 - NW Wash. cold not what a lot of you consider cold) you could stay warm within 5' of stove and burn a couple of wheel barrow loads of wood doing so. Current stove and insulation an arm load or two.