Kachelofen
The kachelofen design, a relatively large home heater surrounded with ceramic tile, has existed for at least five centuries. During the Renaissance period, the builders of kachelofens were part of a distinct trade and were called hafnermeisters. A kachelofen uses a maze-like passage created out of firebrick to release gases and smoke from the wood fire slowly, allowing the firebrick to retain as much heat as possible from the gases and smoke. The ceramic tile surrounding the kachelofen also acts as insulation to retain heat. Kachelofens were carefully designed so that the minimum amount of heat would escape, only as much as needed to warm the flue to maintain a proper air draught. The firebrick used in kachelofen construction holds 80% more heat than ferrous metals such as cast iron, while its heat conductivity is 1/45 that of iron or steel. A kachelofen is efficient enough to warm a house for up to 6 to 12 hours after the fire has stopped burning.
Read more about this topic: Masonry Heater