We like well engineered stuff...

Utilising thermal mass to make wood-based heating is getting very popular with rocket mass stoves, etc.  Here in the colder climates this technology has existed since Neoglacial and Neolithic periods.  I just came in at 2pm and our 100yr old stove is as warm as a typical radiator would be, with the house at a comfortable 20°C and we only lit a very small fire over 12 hours ago.  It's 1 °C outside.  I just fired it up again and this small fire will see us through until tomorrow night.

Various models exist in older homes here, often very beautifully crafted.  There is a knack to learning it's temperaments, but they are highly efficient.  Often they sit as a ornate feature whilst electric radiators do the work these days, sad really.  One thing to be sure of is not to close the damper until the fire is totally out, otherwise you risk carbon monoxide poisoning which still kills a lot of folks every year.

These types of stove are usually made of masonry such as brick (firebrick), tile, stone, stucco, or a combination of materials, rather than steel or cast iron. It is freestanding, and usually requires special support to bear its weight. It consists of a firebox and heat-exchange channels or partitions that provide additional surface area. These absorb heat from the hot exhaust gases before the gases exit into the chimney. The fire in a masonry heater burns much hotter than in a metal stove. Very hot fires reduce emissions significantly. When not being fired, the connection from the masonry heater to the chimney sometimes has a damper to prevent heat from escaping up the chimney; the heat is then radiated from the masonry.

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Masonry takes longer to heat than metal; but once warm, the heater will radiate this heat over a much longer period of time and at a much lower temperature than a metal stove would use (the metal is hot only when there is a fire burning inside the stove and for a short time thereafter). A masonry heater is warmed by fires that burn for a short time; it is mostly the heat stored by the heater's mass that heats the living space. Both in Europe and in America seating and even beds are occasionally built adjoining the masonry stove; this is possible because the heater's exterior surfaces are cool enough to touch safely.

Heat stress is a major concern during the construction of masonry heaters. Differences in temperature inside the masonry core of the heater can result in differential expansion. A skilled heater mason knows how to provide for this stress when designing and constructing the heater, thereby preventing uneven expansion from causing cracking in the exterior.

Masonry heaters take a long time (from 3 hours up to two days) to get up to the right temperature and so are not always practical for taking the chill off a single cool evening or morning, but they are well-suited for long periods of cold weather because they store heat so well and provide dependable, even heat all day and night. Because the radiant heat is given off at a low level a masonry heater is not likely to overheat a home the way a metal stove might in warmer parts of the year like fall or spring.