For anybody who might know.
My Zero Clearance NZ6000 fireplace (epa classified as a furnace) needed a 35:1 air ratio to be EPA exempt. Above my damper there is a large 3x12inch hole which allows fresh combustion air to enter the firebox without any control by me ( I figure this was part of the 35:1). Thought was given to possibly blocking some of this off to gain control of a bigger part of the combustion air. However some thought that maybe this air was used to help cool the exhaust going up the chimney. Could this be true? I'm wondering because I didn't know if large wood stoves have any type of cooling going on before exhaust leaves the firebox and enters the stack (do they?). Mine is not a type of aluminum flex tube but a solid double walled insulated chimney inside an external wood framed and vynl sided outside chase.
For anyone interested the entire reason for this discussion is because my NZ6000 was an older model (2006) with no secondary air tubes. A year later they added a mod to the stove by drilling into the fresh air supply and adding a secondary air tube which helps give it a secondary burn. Napoleon sells the kit to mod this and we are contemplating having our certified installer do it. If done this kit would draw air from a spot 2 inches below the above mentioned cooling hole mentioned above. THanks for any thoughts - Joe
My Zero Clearance NZ6000 fireplace (epa classified as a furnace) needed a 35:1 air ratio to be EPA exempt. Above my damper there is a large 3x12inch hole which allows fresh combustion air to enter the firebox without any control by me ( I figure this was part of the 35:1). Thought was given to possibly blocking some of this off to gain control of a bigger part of the combustion air. However some thought that maybe this air was used to help cool the exhaust going up the chimney. Could this be true? I'm wondering because I didn't know if large wood stoves have any type of cooling going on before exhaust leaves the firebox and enters the stack (do they?). Mine is not a type of aluminum flex tube but a solid double walled insulated chimney inside an external wood framed and vynl sided outside chase.
For anyone interested the entire reason for this discussion is because my NZ6000 was an older model (2006) with no secondary air tubes. A year later they added a mod to the stove by drilling into the fresh air supply and adding a secondary air tube which helps give it a secondary burn. Napoleon sells the kit to mod this and we are contemplating having our certified installer do it. If done this kit would draw air from a spot 2 inches below the above mentioned cooling hole mentioned above. THanks for any thoughts - Joe
