Rocket mass stoves are all the rage right now but we've seen the same concept in the past with Russian stoves and the like. John Seymour in one of his books has a detailed drawing of a massive stove/oven that is fed from the outside. It's a concept worth exploring. I'm actually searching for firebrick and salvaged brick for a project. Thought I had a source last weekend but it was gone by the time I got there. All good, I've increased my readiness this last week in all kinds of ways. Food, seeds, heat, sanitation, sewing and, hopefully communication. I'll know Saturday about the last.