Direct-vented gas fireplace

A zero clearance fireplace of the type adapted to be installed against an outside wall of an interior space to be heated, comprising:

• a box shaped fireplace having six walls comprising four substantially vertical walls, a top wall, and a bottom wall,
• at least one of said four vertical walls having a glass access door and one of said remaining walls having a horizontal exhaust pipe connected thereto for insertion through said outside wall of the space to be heated,
• a combustion chamber in said box shaped fireplace located within said six walls,
• said bottom wall comprising an inner, and an outer bottom plenum below said combustion chamber,
• the wall having said horizontal exhaust pipe connected thereto comprising an inner plenum, a middle plenum and an outer plenum,
• said outer plenums being connected to form an air passage for interior space air being circulated around the outside of said fireplace combustion chamber and exhausted as heated air into said interior space to be heated,
• said bottom inner plenum and said middle plenum being connected together and to a source of outside fresh air and connected to said combustion chamber to provide primary combustion air, and
• said horizontal exhaust pipe being connected to said inner plenum of said wall having said horizontal exhaust pipe connected thereto, said inner plenum being connected to said combustion chamber for receiving and exhausting exhaust gases from said combustion chamber.