Fireplace insert chimney stove surround steel power type ambient air independent heating power 135 kw efficiency 81 fuel consumption 3 9 maximum room size 387 m flue connection top flue connection diameter 200 mm diameter of combustion pipe 120 mm energy sources wood firewood exhaust gas temperature 282 c exhaust gas weight 674 mgs necessary pressure 0 12 mbar combustion systems primary air secondary air tertiary burn design 2 no multipl