Hi Everyone,
Not sure if this is the best place for this topic, but since I have a wood furnace I figured I would start here. I'm hoping the collective knowledge on this forum can help to clear something up for me.
My wood furnace (Harman 2500-A) has a 7" round flue outlet...and thus I have 7" stove pipe running to my chimney flue. I was reading the manual and it states to vent the furnace to a flue "not less than 8" x 8" in size." I was confused on why it would need to be vented to a flue larger than the exhaust pipe...and worried that I spent a bunch of money on a system that won't work with my setup as my chimney flue is 6.5" x 6.5"
Anyway, I was looking online and some sites suggest that the 8" x 8" refers to the Outside diameter...others say the internal diameter. When I measured the outside diameter of me flue, sure enough it is 8 x 8.
My question is, can anyone tell me if the measurements of a flue typically refer to the ID or the OD. In some ways the OD makes sense because an 8 x 8 OD with 6.5 x 6.5 ID measurements gives roughly the same cross-sectional area as a 7" round pipe (but maybe that's just my wishful thinking hoping that I have more than a $3000 paper weight in the basement.)
If more info is required please let me know.
Sean
Not sure if this is the best place for this topic, but since I have a wood furnace I figured I would start here. I'm hoping the collective knowledge on this forum can help to clear something up for me.
My wood furnace (Harman 2500-A) has a 7" round flue outlet...and thus I have 7" stove pipe running to my chimney flue. I was reading the manual and it states to vent the furnace to a flue "not less than 8" x 8" in size." I was confused on why it would need to be vented to a flue larger than the exhaust pipe...and worried that I spent a bunch of money on a system that won't work with my setup as my chimney flue is 6.5" x 6.5"
Anyway, I was looking online and some sites suggest that the 8" x 8" refers to the Outside diameter...others say the internal diameter. When I measured the outside diameter of me flue, sure enough it is 8 x 8.
My question is, can anyone tell me if the measurements of a flue typically refer to the ID or the OD. In some ways the OD makes sense because an 8 x 8 OD with 6.5 x 6.5 ID measurements gives roughly the same cross-sectional area as a 7" round pipe (but maybe that's just my wishful thinking hoping that I have more than a $3000 paper weight in the basement.)
If more info is required please let me know.
Sean
