Wood Burning Masonry Heaters
How it all works.
A Masonry Heater enables the pleasure and spectacular view of a roaring log fire to be a clean and efficient heating source for the home. The efficiency is accomplished by burning the wood fuel quickly at very high combustion temperatures combined with the large thermal mass of the structure.
Many types of Masonry can be used however Soapstone is the perfect natural material for production of these heaters as it is able to hold twice as much heat per tonne than most other fireplace materials and is able to absorb the heat seven times faster.
The wood is burned quickly in the firebox at temperatures between 1200 - 1800º F. The intense combustion temperatures produce superheated, clean gasses which rise up the central core before they are directed downwards through the contra-flow heat exchange chambers, transferring the energy into the Masonry mass.
The gasses are then vented at the bottom of the heater into the base of the chimney and released to the environment as clean very low emission exhaust. The Fire only burns for between 1 – 3 Hours and afterwards the dampers are closed to retain the heat inside the core. The Masonry mass then radiates the heat at an even rate for up to 24 hours. During extremely cold periods it may be necessary to have a second smaller top-up fire each day.
The exterior walls of the unit not only radiate heat but also warm the air surrounding the structure creating convection currents that distribute the warm air throughout the room. The heaters are also extremely safe as unlike iron woodstoves, the exterior of a Masonry Heater never becomes too hot to the touch.
Masonry heaters have far more benefits than the standard metal wood burning stoves, the only downfall being the much higher installation cost of a masonry heater due to its onsite construction and size. See "Comparison between Masonry heaters and Metal stoves".
Soapstone is a metamorphic rock formed hundreds of millions of years ago under intense high temperature and pressure. It is composed mainly of Talc which gives it softness to the touch and Magnesite which ensures its durability and heat retention characteristics. Soapstone comes in varying tones which also enhance its beauty.