If you are considering buying a wood burning stove you will probably come across mentions of soapstone and it's value in stove construction.
In essence soapstone helps store heat and then releases it gradually - in a small stove this can balance hotter and colder temperature differences and in a large stove construction soapstone can store this heat for many hours.
What Is Soapstone? Soapstone is a naturally forming rock that has outstanding thermal properties.
It has been used traditionally for heating for many thousands of years by indigenous peoples, including the Inuits, because it can be shaped easily and does not crack or fracture when exposed to heat.
Soapstone can be carved and shaped into bowls or slabs which can be placed in direct contact with a fire, it conducts heat well so that food can be cooked on it directly and it develops a natural patina from grease which protects the stone and makes it easy to clean.
Soapstone In A Wood Stove The same thermal properties that made it prized hundreds of years ago make it valuable in today's modern stove design.
Soapstone is very dense and has a high specific heat capacity.
It practice this means that a relatively small amount of soapstone can store large amounts of heat.
Soapstone wood stove use this to good effect.
During a normal fire the temperature in the firebox can change substantially over time, depending on many things: how long ago fuel was loaded, how much air is entering the firebox, the type of wood and how well seasoned it is and the design of stove.
The varying temperatures mean that the room can go from feeling too hot to too cold quite quickly.
Soapstone absorbs heat when the stove is hot and then releases it again when the fire is cooler, helping to regulate temperature.
It is far better at this regulation than steel or cast iron, the construction of most modern stoves, and usually gives a more consistent room temperature.
Small wood stoves can be made with specially designed soapstone insert panels, while specially built masonry stoves can incorporate many hundreds of kilos of soapstone.
The Aesthetics Of Soapstone Soapstone comes from many different sources world wide and has a huge variety of colouration and patterning, rather similar to marbling.
Particular quarries tend towards different effects and it is vital that you choose the pieces of stone that you want to incorporate very carefully.
Most dealers will either show you the exact pieces they have on offer, or show similar samples, however there is a lot of variation so try to get a look at the actual piece that will be used.
Thermal Mass Stoves The idea of using heavy materials to regulate heating (and cooling) is not a new one, in fact our prehistoric ancestors made use of it when they lived in caves.
Their small but regular cooking fires and body heat warmed the stones of the caves they lived in so that they enjoyed a stable year round temperature, never too hot or too cold.
Other examples of thermal mass stoves used today are.
- Rocket Stoves:- a clever if rustic design usually handmade from local material and weighing around 2 tonnes.
A single intense fire heats the mass over the space of a few hours but releases heat to the room for up to a day. - Masonry Stoves:- Clever brick work is used to ducked the hot flue gases around a heavy, overside chimney breast.
These can look very similar to traditional chimneys and usually form part of the structure of the home such as a stairway or supporting pillar.
They can be made to incorporate bread baking ovens or other cook stoves. - Russian Fireplaces:- These are similar to the more sophisticated Masonry Stoves in that they have a convoluted flue and the heat is stored in the brick work of the chimney.
They are less common today but could supposedly heat a home from a single load of wood each morning, releasing heat over the day. - Stone Surrounds:- simply having plenty of heavy stone work or concrete around your wood burning stove will go a long way to regulating temperatures.
It will heat up while the stove is hot and then gently warm the room while the stove is out.
Simple yet effective.