I just built a new firebox door for my masonry offset smoker. I put a large vent low on the door for air to flow under the wood grate and another smaller vent up higher..... because I think that's a good thing. But I have to admit, I don't really understand exactly the function of the vents and how they might best work together.
I do of course know that the low vent is to provide air directly under the fire. But how best to use the upper vent - what conditions would prompt a knowledgeable operator to open or close it?
Any guidance would be greatly appreciated.
Terry on Tampa Bay, Florida, USA
Picture of my firebox door below: