Standard wood fired vs. airtight

[doocat]

Can anyone explain to me why the old wood arch has a ramp and why the new style aritights are flat back fireboxes with the rear of the arch not up tight to the flue pan to force fire through the flues?

Thanks

[Flat Lander Sugaring]

i honestly dont know but I'm guessing the old style arch relies on the ramp and air being let in by the draft door to get it going and ramp probably helps it. With the ait tight arches and the forced air the fire has no other way then to go up because of the squared up fire box area.