Control of Wood Burning Stoves?

[ericmark]

Particulate pollution it would seems means the pot bellied stove is now a thing of the past, and wood burning heating systems now have a number of methods to ensure a complete, controlled burn to the wood. With sophisticated baffles and air supply control, catalytic converters, electrostatic, or high pressure water these pollutants are removed. The main change seems to be a double burn where the air in the bottom of the stove controls how quickly the wood burns but a secondary air supply higher in the fire box ensures the burn is full with no tar or other waste products going up the flue and also the flue temperature is carefully controlled. Reading it would seem when wood is added to a fire there are two stages the first where the stove is allowed to get very hot reducing the logs into charcoal the second with the stove running cooler while the charcoal is burnt. Theory is great but in practice one does not sit monitoring the fire all day one just checks it from time to time. As the wood reaches the charcoal stage of the burn the air supply into the bottom of the stove needs closing and clearly this gives a need for automatic control. Be this timer or some sensor is really beyond my ken which is the reason for the post. Catalytic converters, electrostatic or high pressure water all need electric power and it would seem the sophisticated baffles and air supply control would also need some electric supply to shut down the air supply once the logs have become charcoal. Yet I read the adverts for wood stoves and there is no reference to electrical requirements. OK could be battery, but to ensure economically use of the wood I would expect some automation needing more than supplied by batteries. Also this two stage burn would it would seem also mean a two stage heat output. So some method of storing the heat during high output and then supplying it to the home during low output would also be required. This is of course done with solar panels with storage systems like the megaflow but it would also need some indication as to if low or high in energy so the user knows to add more or less fuel. Yet at the same time one would not really want the burner to go out. Look as I can I can’t see how the amount of heat stored is used to regulate the burn rate of the stove. Could anyone point me to the details on how the integrated system is controlled please? Easy to understand each part but not how it all comes together as a whole.

[stoneyboy]

Hi ericmark,

I’m not sure exactly what you are asking – what you describe does not relate to the domestic multifuel stoves I have used/fitted.

The more basic and cheaper ones have a controllable air supply fed under the grate and that’s it apart from an air wash supply for the glass.

The more expensive ones do indeed have a secondary air supply fed in above the normal burning area. I do not think this has anything to do with an improved burn and I suspect it is purely there to dilute the flue gases so that the fire meets European emission regulations.

The only time I have found an electric supply is needed is where the fire includes a convection chamber around the fire box and electric fans can be added to force air around the chamber.

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