Recovery of hot air in the chimney flue

[marco333]

Hello, thank you for opening my account. Following the installation of an insert in my open fireplace, I drilled the old chimney flue through which the exhaust pipe of my insert passes. I collect the hot air and with a hot air circulator, I send this air to the end of the corridor through a double insulated aluminum duct. The heat obtained is very good and even too much, so I regulate it by turning off the circulator. My concern is the smell and I cannot leave the system running because there is a possible risk of dangerous gases. What is the problem? The old duct in which heated soot must remain, the smoke duct of the insert which is not waterproof? Should this installation be removed because it is too dangerous, can we put filters? Thank you for possible solutions.

[Macro]

“The water in the firewood escapes as vapor, but as you cool your flue, this water vapor will condense on the walls of the flue.

From then on, droplets of water are deposited on the walls of the conduit, mixing with the soot to form a hard and sticky crust commonly called bistre."

[sicetaitsimple]

Hello, thank you for opening my account. Following the installation of an insert in my open fireplace, I drilled the old chimney flue through which the exhaust pipe of my insert passes. I collect the hot air and with a hot air circulator, I send this air to the end of the corridor through a double insulated aluminum duct. The heat obtained is very good and even too much, so I regulate it by turning off the circulator. My concern is the smell and I cannot leave the system running because there is a possible risk of dangerous gases. What is the problem? The old duct in which heated soot must remain, the smoke duct of the insert which is not waterproof? Should this installation be removed because it is too dangerous, can we put filters? Thank you for possible solutions.

according to the description of the problem, the most probable is indeed a conduit of the insert or its leaky connection. In which case it is absolutely necessary to shut down the system until repaired.

[Christophe]

A diagram please? Even freehand...

[Macro]

it recovers the hot air between the tubing and its old traditional conduit. Traditional conduit having already been used...It recovers smoke odors in my opinion not very dangerous but unpleasant. on the other hand the cooling of its fumes could be problematic...

[sicetaitsimple]

it recovers the hot air between the tubing and its old traditional conduit. Traditional conduit having already been used...It recovers smoke odors in my opinion not very dangerous but unpleasant. on the other hand the cooling of its fumes could be problematic...

This is also what I understood. If in doubt (between smoke leaks and just "smells"), personally I would refrain.