Sometimes less is more
Today I'll be discussing construction styles, not channel layouts or firebox designs, but here I will give a brief overview of some ways that masonry stove durability has been addressed.
Masonry Heaters originate in many places around the world, and different cultures came up with different ways of overcoming the challenges faced when designing a masonry heater, which are pretty simple:
1. Effectively design a firebox to be the right size and shape to hold the right amount of fuel and optimize mixing of air with wood-gas.
2. Balance heat exchange area, firebox size, and wall thickness to absorb, store, and radiate that heat effectively while leaving enough heat in the gasses to allow chimney draft to keep the overall system under negative pressure.
3. Hold together under the stresses of expansion and contraction that are produced by the heating and cooling cycles inherent in the operation of the stove. Today we live in many different shapes and sizes of house so we take these things into account with each stove we design, but plenty of heaters have been built so it's just a question of which approach we want to use for which situation. Masonry Heaters in the United States In some parts of the world, there is an outer stove wall made of a 4- to 4.5-inch thick softer, higher porosity brick than we have in the USA. These walls have the room on one side and the exhaust gas on the other, with no firebrick except the firebox and area right around it (where the highest temperatures are found). In some cases the red brick is plastered, which adds a layer of air-tightness to the stove. In the USA, the most common construction I'll call “core and skin.” A firebox and heat exchange