Heater Rated at 35,000 Btu input, the Madison Multi-Sided system draws in outdoor air to support combustion and sends its exhaust directly outdoors, and must be located in a position that allows venting through an exterior wall or through the roof. Madison Multi-Sided fireplaces install using readily available 4 x 6 5/8 direct-vent pipe.Madison Multi-Sided systems include a built-in 24-inch Slope Glaze Vista Burner, large tempered-glass viewing windows, Banded Brick Liner, ceramic fiber floor liner, dimmer controlled lighting, and glowing embers. The 24-inch Rock Creek Log Set and barrier screens must be ordered to complete the fireplace. (Doors are not available for multi-sided fireplaces.) Options & Accessories Decorative Louvers Decorative Louver ArchDecorative Louver Mission Extruded Aluminum Frames Frame and Bottom Trim Colors Not available for Peninsula models.Matte Black (Shown on Cherry Mantel)Hammered Pewter (Shown on Oak Mantel)