Why are fire boxes small and not large?

[zandstrafarms]

Sounds crazy i know, but husband wants to know why arches use such small fire boxes and not a huge furnace? Why not make fire box full length of 6ft or 4ft or whatever your arch is.

My guess was it helps airflow upward to chimney and because most wood splitters don't split greater than 20in. , lol.

What's the real answer?

[wnybassman]

Efficiency. I think the design of an arch is to take the least amount of wood/fire and compress those heated exhaust gases (via the ramp) to heat the rest of the pans bottom.

[Schiefe4]

I'm pretty sure your newer gasification arch styles have fire boxes that are up to 50% the entire length.