Uh oh, not the coaling debate again! We can fill a firebox with coals, if pushing things. This morning it was around 10 degrees, and the large coal bed was able to maintain our home at 70 or above for a few hours, before reloading. I do what many others do, and rake coals forward and open the damper. They glow white hot and keep things warm, while burning down. If more heat is needed in this process, then we place one split east-west on top. Doing this once or twice manages to burn things down for another load. Here soon I'll be hitting more projects around the home, which will tighten things up. The more efficient the home, the less worry about too many coals. When a home stays warm off a nice coal bed, it's not a problem.