I love the ash pan in my Oslo . . . it's one of the outstanding features . . . it's very easy to dump the ashes in a 5-minute job . . . and that includes the walk outside to my ash can.
So how do I handle the ashes in the ash pan. When the ash pan is full I dump it. I have seen no change in the temps, fire behavior, etc.
Now what I do not do though is clean out all the ash and coals in the firebox . . . generally I stir up the ash and coals in the firebox before removing and dumping the ash pan . . . being sure to leave at least an inch or so of ash and coals in the firebox . . . this helps insulate the base to some degree (although I suspect the air space underneath the Oslo and the ash pan with the air space also help to insulate the base) . . . but just as important to me is that having a layer of ash helps preserve the coals after an overnight or overday burn.
So how do I handle the ashes in the ash pan. When the ash pan is full I dump it. I have seen no change in the temps, fire behavior, etc.
Now what I do not do though is clean out all the ash and coals in the firebox . . . generally I stir up the ash and coals in the firebox before removing and dumping the ash pan . . . being sure to leave at least an inch or so of ash and coals in the firebox . . . this helps insulate the base to some degree (although I suspect the air space underneath the Oslo and the ash pan with the air space also help to insulate the base) . . . but just as important to me is that having a layer of ash helps preserve the coals after an overnight or overday burn.