Thermally balanced air flow chimney

An on demand air cooled three wall chimney system for a building sourcing cooling air from within said building comprising:

• a. a starter chimney member having a first inner sheet metal wall forming a first imperforate elongated open ended chamber for the passage of flue gases from a fire source;
• b. said starter chimney member having a first intermediate sheet metal wall surrounding and generally evenly spaced from said first inner wall and forming therewith a first insulation chamber;
• c. said starter chimney member having a first outer metal wall surrounding said first intermediate wall forming a first open ended air passage chamber;
• d. first insulation material substantially filling said first insulation chamber in said starter chimney member;
• e. air passage means formed only in said lower portion of said starter chimney member permitting said air within said building to enter said first air passage chamber aajacent the lower end of said starter chimney member for movement only upwardly through said first open ended air passage;
• f. an upper chimney member having a second inner sheet metal wall in over lapping registration with said first inner sheet metal wall forming a second imperforate elongated open ended chamber for the passage of flue gases from said first imperforate elongated open ended chamber to the atmosphere outside said building;
• g. said upper chimney member having an intermediate sheet metal wall surrounding and generally evenly spaced from said inner wall and forming therewith a second insulation chamber;
• h. said upper chimney member having a second outer metal wall surrounding said second intermediate wall forming a second open ended air passage chamber positioned for communication with said first open ended air passage chamber;
• i. second insulation material substantially filling said insulation chamber in said upper chimney member;
• and
• j. a chimney cap means mounted externally of said building having a conduit in conmunication only with said second imperforate open ended chamber of said upper chimney for venting flue gases to atmosphere and a passage in communication only with said second open ended air passage chamber of said upper chimney member for venting said cooling air to atmosphere separately from said flue gases.