To what is the rate of combustion directly related, concerning wood?

The rate of combustion concerning wood is directly related to the surface area of the wood. When wood burns, the combustion process requires oxygen, and the rate at which it can absorb oxygen is closely linked to its surface area. A larger surface area allows more oxygen to contact the wood, facilitating a faster and more intense burn.

For instance, small pieces of wood, like kindling, have a greater surface area to volume ratio compared to larger logs, which enables them to ignite more quickly and burn more rapidly. Conversely, when wood is in larger chunks, the combustion process is slower because less surface area is exposed to air.

Other factors, such as the age of the wood, the volume of ignition fuel supply, and the grain type, can influence combustion, but they do not directly determine the rate of combustion as significantly as surface area does. Age can affect moisture content and density, fuel supply impacts initial ignition, and grain type can alter burn characteristics but ultimately, it is the available surface area that plays the most crucial role in combustion rates.