The Vogelzang Norsemen Add-On Furnace provides either a primary or supplementary source of heat for your home or workshop. Connects to your furnace duct and plenum as a safe, efficient heat source. Furnace is fully firebrick lined and has a shaker grate for wood or bituminous coal firing. Accepts 24in. logs and delivers up to 8 hours of heating per load. Bi-metal thermostat controls combustion.Safety tested to UL 391 6 Round flue size Protective smoke curtain Heats up to 2,500 square feet Adjustable bi-metal thermostat Adjustable, cast iron spin draft Heavy-duty 7 gauge steel firebox Ash door and full-length ash tray Cast iron, 7-ga steel construction Furnace uses TWO 550 CFM blowers that blow through two raised 8 Ash door with large ash pan makes ash removal easyBlower (CFM): 1,100 Blower Included: Yes BTU Heat Output: 115,000 Collection: Norseman Depth: 39 Door Opening: 12W x 11-1 2H Firebox Capacity (cu. ft.): 8.75 Fuel Type: Wood coal Full Load Run Time (Hours): Up to 8 hours Heat Settings: Yes Heating Capability (sq. ft.): 2,500 Height: 32 Igniter: Manual Size: Large Thermostat Included: Yes Width: 24