
Their fireboxes are lined with firebrick, refractory
concrete, or similar materials that can handle
temperatures of over 2,000°F (1,093°C).
A small hot fire built once or twice a day releases
heated gases into the long masonry heat tunnels. The
masonry absorbs the heat and then slowly releases it
into the house over a period of 12–20 hours. Masonry
heaters commonly reach a combustion efficiency of
90%.
Most are intended for burning wood, but they were
historically designed to burn almost any type of solid
fuel.
The relatively small, but intense fire also results in
very little air pollution and very little creosote buildup
in the chimney.
Because most of the heat from the fuel is transferred
to the masonry and slowly released into the room
over the day, this type of heater does not need to be
loaded with fuel as often as other types of wood
heating appliances.
In addition, if the masonry heater is built where
sunlight can directly shine on it in the winter, the
heater will absorb the sun's heat and release it slowly
into the room.
A wide variety of masonry heater designs and styles
are available. Larger models resemble conventional
fireplaces and may cover an entire wall.
Smaller models take up about as much space as a
wood or pellet stove. They can be custom-built or
purchased as prefabricated units.
Some large designs may cost $5,000 or more. Plans
and kits are available, but they are not easy do-it-
yourself projects and require experience in working
with masonry.
In addition to their expense, masonry heaters have
one significant disadvantage when compared to
conventional wood stoves and fireplaces: They cannot
provide heat quickly from a cold start.



Alternative-Heating-Info.com
Masonry Heaters
Masonry heaters are also
known as "Russian,"
"Siberian," and "Finnish"
fireplaces.
They produce more heat and
less pollution than any other
wood or pellet burning
appliance.
Masonry heaters include a
firebox, a large masonry
mass (such as bricks), and
long twisting smoke
channels that run through
the masonry mass.