A friend asked this on another forum. “The problem I'm having is with coals. When I load up the empty firebox in the morning I get great heat out of the resulting roaring fire. Eventually of course, the logs burn down and the heat output lowers some and I then add more logs and the output rises again. Rinse and repeat. But after about 5 hours of this, eventually the level of red hot coals builds up quite high in the fire box thus physically limiting the amount of room available to add in more logs so therefore I get a reduction in heat output despite the box containing a large amount of coals.”
Many will recommend pine to burn down those coals. A single peice at a time. I think ultimately he needs to make his split sizes smaller.
Good advice...pine, or any fast burning/low coaling wood will do. Also, might go without saying here, but if he is a new burner he may not know that he can rake those coals into a nice pile toward the front of the stove, then open the air up some, they'll burn down some, while making some heat (not as much as reloading, but more than just letting them linger in the ashes) Also, if he is burning a high coaling wood, like Oak, mixing in something less dense on each load can help too.
What type of wood is he burning? Is he really burning logs? How many times is he reloading in a 5 hour period? I'd reccomend more air and or smaller splits. Also as was already suggested mix wood types.
I used to just open the stove door, let the heat radiate until the coals dissipated some. This was only on an extended burn from early morning til late afternoon and overnight. Never knew the pine trick then.
Most manufacturers specifically say not to...pretty easy to overheat stove internals/etc that way, it can turn a pile of semi hot coals into literal forge temps quickly.
Once the coals build up, load it a few times with only a stick or two and open the air up a little bit more. Or like mentioned, burn some softer wood mixed in
