20
ENGLISH RAIS - manual for SIRA & SIRA SOAPSTONE
21
ENGLISH RAIS - manual for SIRA & SIRA SOAPSTONE
Regulating the combustion air
All RAIS stoves are equipped with a one-handed operating lever for regulating the damp-
er. The stove-specific regulating mechanisms can be seen on the diagrams.
Primary air is the combustion air added to the primary combustion zone, i.e. the bed of
glowing embers. This air, which is cold, is only used in the lighting stage.
Secondary air is the air which is added in the gas combustion zone, i.e. air which contrib-
utes to the combustion of the pyrolysis gases (preheated air, which is used for the cleaner
glass system and combustion). This air is drawn through the damper under the combus-
tion chamber and is pre-heated through the side channels and then emitted as hot air
onto the glass. The hot air rinses the glass and keeps it soot-free.
The tertiary channel, which can be seen at the the top of the combustion chamber to-
wards the back, serves to combust the final gas residues.
By setting the interval between position 1 and 2, the energy content in the firewood is
used optimally, as there is oxygen for combustion and for the burning of the pyrolysis
gases. When the flames are a clear yellow the damper has been set correctly. Finding the
correct position comes with time after you have used for stove for a while.
It is not recommended that you turn it down completely. A mistake commonly made is
shutting the damper too early because it feels too hot. This results in dark smoke ema-
nating from the chimney and in the calorific value of the firewood not being used to its
fullest.
Control
If the ash is white and the walls in the combustion chamber soot-free after the stove has
been used, the air regulation was set correctly and the wood was sufficiently dry.
Using the wood burning stove
Adjustment of the air damper.
The damper has 3 settings.
Position 1
The air damper is closed, which means no air supply.
Position 2
Pull the lever until first stop. This position gives full
secondary air.
During normal stoking the lever is set between posi-
tion 1 and 2.
When the flames are clear and yellow, the damper is
set correctly, i.e. resulting in a slow/optimal burning.
Position 3
Pull the lever until next stop.
The air damper is completely open and gives full
primary and secondary air.
The position is for the lighting stage and is not used
under normal operation.