History:
In many countrys the Finnish fireplaces, develloped by Heikki
Hyytiainen
during the 70ties, are well known.
It is from his work, and my own former work, as a advisor for the
Danish
Goverment in quistions of efficient combustion, that i have
carried on
develloping these stoves, during the last 25 years.
Today theese stoves are develloped to never the less than extreme performance.
Clean combustion: 0,13% CO at 7,5% CO2 (means no visibel smoke from the chimney).
High efficiency:
More than 87% (European standard) of the calories in the wood,
becomes
very nice and long lasting heat in the house. (This is about 10%
more,
than the ordinary Finnish Fireplaces, or Canadian Masonry
Heaters.)
10% of the calories is used to perform the nessesary draft in the
chimney.
That means, that allmost every calori in the wood, is made
usefull.
Furthermore, this happens without any kind of use of electric
equipment
at all.
As long as you have firewood in the shelter, you have a nice warm
house.
Outputvariaty: 0 to 8 kw without any loss of efficiency.
Variaty of temperature in the house: + - 2 degree C. during more
than
24 ours after a short fire.
(Easy to operate)
Creative adabtability to any home.
Great beuty (a matter of taste of course)
Tested and documented by the The Danish Institut of Tecnology
Materials:
Besides the doors and dampers, which are factory made from
castiron
in Denmark and Finland (Morsoe and UPO), everything is handmade
stone by
stone.
Inside we use the best fireproof and shock resistent bricks we can
find at any time. The mortar here, is the same material crushed
and mixed
with natriumsilica.
Outside we use ordinary bricks and claymortar (clay, sand and
water).
The clay mortar has the ability, that cementmortor lacks, to
stretch
and bend and this way absorb the forces that occur during the
heating up
and cooling down cykles. Furthermore, claymortar can be reused
again and
again. You would not notice, if the mortar you are using was part
of a
house centuries ago. Fore the same reason, you can allways, and
very easely,
repair any small cracs that might occur. We dont se mutch of them,
but
it happens, and is no problem at all.
We consider, that the lifetime of ours stoves very often will be mutch longer, than the lifetime of the house which they serve.
Technology:
Efficient combustion of wood needs 3 things:
High temperature (above 900 C.)
Good turbulence (mixture of gases and oxygen)
Time – (to finish the combustion before taking away the produced
heat).
We call it “The 3 T´s” just to remember.
If one T is missing, your fire will make smoke.
To obtain the 3 T´s as fast as possibel in a lot of relatively
cold bunch of stones, i develloped a new “device” called “the
centrifugal
carburator”.
In this “device”, the burning gasses are forced into a cirkular
movement,
and will this way be surrunded by new burning gasses. This way it
is eaisy
to kepp up high temperatures in the burningzone. Furthermore – the
heaviest
gasses, that are the most difficult to mix with oxygen, will be
forced
by the the centrifugal forces, to stay in this chamber and in the
cirkular
movement, untill they are mixed with oxygen, can burne, and that
way become
lighther, get into the mittel of the cirkel, and get out of the
chamber
to the downdraft channals.
You dont se this “device” in the stoves. It just looks like an
ordinary
bakeowen with a hole in the mittel of eatch side, but you se it
clearly
in the amount of carbondioxyd in the smoke.
The ordinary “hill” in the beginning of sutch messurings, is
extremely
short and low.
Heat transfere.
All the bricks in sutch a stove, obviusly gives the possibility to
store a lot of heat.
The bricks at the outside of the stove however, allso determine
how
fast you can get the heat out of the stove to heat the house.
If the way from the core to the surface of the stove is to long or
to difficult (many layers), you will get the heat out slower (less
heat
pr. our).
Some masonry heater builders thinks, that “ the bigger the
better”.
That is the biggest mistake you can make. I have seen to many
gigantic
stoves, that just could´nt heat up an ordinary house.
If you goes from just one layer of bricks between the
smokechannals
and the livingroom, to two layers, the output will fall drasticly
to less
than a thirdpart of just one layer. So take care about this,
wheater you
want to build a stove, ore buy one.
A masonry heater should allways be builded according to the
actual house
and the surroundings, where it shall function for many years. No
one will
ever move it, would they ?`
How to increase the output
The temperature of the surface, and the size of the surface, is
the
main factors to ajust the amount of heat you can get from a
masonry heater.
My partner and i wanted to se, how simpel we could build a stove,
without
selling out of the main qualitys (clean burning, high efficiency
and a
heating period of 24 ours pr. fire.
At the same time we wanted to make the period of a fire longer.
Many
of our custumors wanted more than just 1-2 ours of firing pr. day,
that
was the nessesary in the stoves we had builded untill then.
So one day we made “Gymse”.
A cute little stove, whitch showed surprising opportunities.
The burning chamber is smaller, so the fire can burne efficient
for
a longer period, without an unacceptabel rise in the temperature
of exhoust.
Even if the stove itself is smaller, the possibility of getting a
high
output is very mutch there. In fact, this stove can produce twice
as mutch
heat pr. our, than the ordinary stoves. To do this, it needs a
long (or
wide) hot beanch.
This way the stove can be placed up to 4 meters away from the
chimney
!
Most surprising, this stove can be fired with open door, or
without
the door at all. Off course without any smoke in the livingroom.
The efficiency is still reasonable good, allthough it is better
with
the door closed.
Hot beanches has been very popular. This combined with the
possibility
of an open, but efficient, fireplace, has made this litle stove
very popular,
even if we still dont have official testresults, as we do with the
big
stoves.
Hot water:
All the stoves meantioned here, can be made to supply your
hot-water-store.
Combined to a solarheating system, hot water is just there at all
time
(allmost).
Education:
Here at the little island Drejoe, we are right now building up an
education
– and develloping center for mainly masonry heaters.
This year 2009, we offer courses of 8 days in masonry heater
building.
I have been teatching in sutch courses for many years, but i have
allways
missed better circumstances to do this. (Several different stoves
in function,
laboratory equipment, possibility for the participants to build
without
consideration for the poor owner of the result, and so on).
If you schould be interested, please mail me at lars@stenovne.dk
as
soon as possibel.
More information at my homepage: www stenovne.dk (The English
version
have not been updated for a longer period, sorry, i hope to do
something
about it soon.)
(Thats why i put this on).