Hi All,
Firstly I can't claim any credit for this one, the BIL is an HVAC /control engineer and its his hard work.
Recently installed automatic air control (and log addition warning and online temperature monitoring) for our log burner that I thought I would share.
(This is the view under the log burner.)
The system takes flue temperature (via an external mounted thermocouple) and a room air temperature sensor to control a electrical actuator to drive the air damper.
The system is driven by a trend controller
Some clever software
Which drives the air damper via an electrical linear actuator
This is the temperature graph as the damper comes in and out. (Viewable from an app on the phone via the controller's IP address.)
The first hump is the initial kindling and log, then the next group of humps is the first filling, then the second filling and left to burn out.
(Disregard the actual temperature numbers, this is because the flue thermometer is external. Its mounted via an aluminum heat sink so a much lower rated thermocouple is needed, it just adds some lag to the system).
The system considers the flue temperature to control the damper. It also factors in the room air temperature and if the room is "cold" it burns harder until the room is up to temperature. There is also overheat control if the fire runs away it closes the damper and a emergency over-ride. Once the damper is open over 80% and the temperature drops below a set point and not increasing it triggers a red light meaning it needs another log.
Very effective, increases the length a log will last and no need to get off the sofa to adjust the fire :lol:
Cheers,
Richard B.
Firstly I can't claim any credit for this one, the BIL is an HVAC /control engineer and its his hard work.
Recently installed automatic air control (and log addition warning and online temperature monitoring) for our log burner that I thought I would share.
(This is the view under the log burner.)
The system takes flue temperature (via an external mounted thermocouple) and a room air temperature sensor to control a electrical actuator to drive the air damper.
The system is driven by a trend controller
Some clever software
Which drives the air damper via an electrical linear actuator
This is the temperature graph as the damper comes in and out. (Viewable from an app on the phone via the controller's IP address.)
The first hump is the initial kindling and log, then the next group of humps is the first filling, then the second filling and left to burn out.
(Disregard the actual temperature numbers, this is because the flue thermometer is external. Its mounted via an aluminum heat sink so a much lower rated thermocouple is needed, it just adds some lag to the system).
The system considers the flue temperature to control the damper. It also factors in the room air temperature and if the room is "cold" it burns harder until the room is up to temperature. There is also overheat control if the fire runs away it closes the damper and a emergency over-ride. Once the damper is open over 80% and the temperature drops below a set point and not increasing it triggers a red light meaning it needs another log.
Very effective, increases the length a log will last and no need to get off the sofa to adjust the fire :lol:
Cheers,
Richard B.