David L. Basically our
Rocket Mass Heater is made from locally sourced materials, and was originally designed to be cheap! Personally,
I do not consider this to be a flaw !
Here is a generally complete list for an 8'' model-
Bricks,can be used 60-90, 1/2 could be soft fire brick
Clay or clay soil
Sand - builders sand preferred
Straw - many substitutions allowed
15-18 gal grease barrel -outside shell of
feed tube
30 -55 gal barrel - heat exchanger
8'' diameter stove pipe/ductwork
Insulation: vermiculite,perlite or pumice
a 4 cu.ft bag is
enough
Insulation retaining container tin shell or body of a
used
hot water heater !
scrapes of hardware cloth and- Rocks and bricks
old broke up pieces of
concrete
The clay, sand, and straw will be used to make
cob which is found in multiple story Buildings 100s of years old ! -You can thick of this
material as being virtually the same as adobe think of the Spanish Missions in the American SoWest some dating from the 1600s
The
rocket mass heater does burn at high temperatures and creates a zone where the eggheads start talking about fire as a plasma,
virtually a 4th state of matter In a well balanced
Rocket mass heater this 'plasma field' or 'perfect flame edge' occurs just before the hot
exhaust gases reach the 55 gallon barrel in a near Oxygen deficient state, because of this there can be no Oxidation or rusting on the
inside of the barrel !
There are 20 year old Rocket mass
heaters that have been in continuous use during their seasonal heating cycle that still have their
original barrel -Find me a conventional fossil fuel fired furnace with a warrantee on its heat exchanger longer then 20 yrs !
The stove pipe that snakes its way through the heat energy storing Thermal Mass is considered a sacrificial form to make gas passage
-ways a failure of this pipe will be totally backed-up by the dense cob mass that will only let heat energy travel through it not liquids or
gas !
If you are looking for more, in the way of "true facts,'' let me direct you to rocket stoves.com Where you can pick up a PDF Copy of
Evans' and Jackson's great book 'Rocket Mass Heaters' $15.
oo U.S.! There is no other source of
Rocket Stove-types information
in any other book in any language ! ( and I don't make a dime !) For the Good of the Craft ! PYRO Logical Big AL ! - As always, your
questions and comments are solicited and are Welcome ! A. L.
