Question about Coal+Wood stove vents

[KiloWatts]

My Old Mill stove was designed to burn both coal and wood:



Am I correct in thinking the top vents are to be used with wood, and the bottom vent for coal? The idea being that coal fires should have air coming from below, and wood fires do better with air coming from above-ish. Is this right?

 

[Bruce Miller]

Kind of Yes...

I burn coal as my primary heat source in my house.

I have a DS basement stove that also CAN burn wood but not ideal.
When loading and gassing down your coal you do want air over the coals so you would leave those upper spinners open some until you have good red bed from the coals.
Other wise your stove builds up gas and you get a bit of an explosion from the coal gasses. This is on reloads and shake downs.

Also when loading coal do it in stages, load some not a full fire chamber, leaving a little bit of fire exposed as to burn off gasses.

After your coal bed has been light up and the temperatures of the stove have gone through their fluctuations of firing up and settling down (for my stove it takes about 1,1/2 hours) and the coal has had a chance to gas off. then you can close the top spinners and just control the burn(heat) with the bottom spinners

Be patient in shutting the upper spinners down, down rush it.

 

[Bruce Miller]

BTW do you have shaker grates on that stove...It is a must for coal.

 

[KiloWatts]

Thank you. Yes, it has shaker grates. I will mostly be burning wood though. I've been using _only_ the bottom vent, and I was thinking maybe that's making the wood burn too fast. I'll try only using the top vents this time and see if I can slow things down a bit.

I've never burned coal before, but I've been gathering a lot of info from this forum. I'll give it a shot this winter and see how it goes.

 

[Bruce Miller]

Coal and wood are different animals, you do not control the burn the same way.

 

[begreen]

Yes, coal needs air below the coal bed. Wood is the opposite. Open all the vents on startup then close the bottom vent once the wood is burning and control the fire with the top vents.

 

[KiloWatts]

Thank you - I've got a fire going now with the lower vent closed and only using top vents. Already I can hear the airflow more this way, and it seems like I have much more control over the fire with the slightest adjustments. I'll continue playing with it. Does anyone ever close 1 side and only use the other? Currently I'm adjusting both sides the same.

Before when I was using only the bottom vent I was reloading every hour. I'm hoping doing the opposite will save me a significant amount of wood. It looks like most people are reloading every 3-4 hours, which would be a gigantic improvement.

 

[begreen]

Adjust both sides the same.

 

[KiloWatts]

Thanks - I'm finding I have the best control when the vents are just barely open to let a whisper of an air stream through. Amazing how sensitive it is. I know I can only expect so much out of a stove this age though. 3-4 hours will probably be the max here with wood, although I still have a few things to try.