I have a brick and masonry chimney that is built on the outside edge of our 1920s house. Originally, it was primarily heated by an oil furnace, and the fumes were vented through a second flue that is now decomissioned. The other flue connects to a fireplace in the living room, and still my family likes to sit around and burn a big fire and enjoy the flames. However, it does absolutely nothing to heat the house, it actually cools things down. I feel like I've reached a stalemate trying to improve how much heat we might actually get from this thing.

• According to city code, an insert or freestanding stove cannot legally be placed in there because no standard 8" pipe, even when ovalized, can fit through the very narrow double-bricked ledge leading into the first flue. http://www.seattle.gov/documents/Departments/SDCI/Codes/SeattleResidentialCode/2015SRCChapter10.pdf

• Even if a stove were vented directly into the smoke chamber to draft up the flue, the hot air doesn't draft through the house at all, it merely rises up and out of the flue. This also excludes something like a fireplace back which, while it might get hot, would simply sit in the dark, cold chimney chamber and slowly conduct heat upwards, out the flue

• The negative pressure of hot air rising out of the flue, and from burning is merely drawing cold air in from the windows all around the house.

I think I were an engineer, I would design a stove or insert that supplies cold air from outdoors via a separate line to burn the fire, vent it out of the chimney in a completely sealed system, and then use a separate electric fan to blow the hot air around the stove into the room.

I have a brick and masonry chimney that is built on the outside edge of our 1920s house. Originally, the house was primarily heated by an oil furnace, and the fumes were vented through a second flue that is now decomissioned. The other flue connects to a fireplace in the living room, and still my family likes to sit around and burn a big fire and enjoy the flames. However, it does absolutely nothing to heat the house, it actually cools things down. I feel like I've reached a stalemate trying to improve how much heat we might actually get from this thing.

• According to city code, an insert or freestanding stove cannot legally be placed in there because no standard 8" pipe, even when ovalized, can fit through the very narrow double-bricked ledge leading into the first flue. http://www.seattle.gov/documents/Departments/SDCI/Codes/SeattleResidentialCode/2015SRCChapter10.pdf

• Even if a stove were vented directly into the smoke chamber to draft up the flue, the hot air doesn't draft through the house at all, it merely rises up and out of the flue. This is particularly bad because the firebox is basically on the exterior of the house. My memories of "grandpa's little wood stove" heating the whole house (with no fan) was because the stove was centrally located with a stove pipe venting through the roof.

• For this reason, I'd be averse to trying something like a fireplace back which, while it might get really hot, would simply sit in the dark, cold chimney chamber and slowly conduct heat upwards, out the flue. I don't believe the claims that fireplace backs "reflect heat" into the house as stated here: https://www.owenschimneysystems.com/benefits-using-fireplace-fireback/

• The negative pressure of hot air rising out of the flue, and from burning is merely drawing cold air in from the windows all around the house.

I think I were an engineer, I would design a stove or insert that supplies cold air from outdoors via a separate line to burn the fire, vent it out of the chimney in a completely sealed system, and then use a separate electric fan to blow the hot air around the stove into the room.

My question is: am I completely out of options for moderately efficient wood burning heat?