Primary air is defined as the combustion air for burning “the mass of wood” and stipulates
the production of volatile.
Secondary air is used to burn off the volatile at high temperatures (above 1000 degrees
°F/540°C) and to keep the glass free of soot.
Basically, the primary air is used to start the fire, and the secondary air is used to maintain
the fire.
Firewood used should be split wood with an adequate low degree of moisture 15 – 22 %,
length 30 – 34 cm. In order to achieve this wood should be stored in a dry place under roof
with sufficient fresh air for at least one full year for soft tree sorts and minimum two full
years for harder wood sorts.
Building the fire
To start the fire lay 2 or 3 kindling blocks topped with twigs or dry kindling wood at the
back of the firebox (app. 2 kg). Build the wood directly on the stove hearth, and do not use
a grate or elevate the fire.
Pull out the handle for air control out to position 1. Light the fire – and during start up leave
the door slightly cracked (with supervision) about 1-2 inches/10-15 mm, until you have
clear flames. After 3 – 5 minutes close the door completely. After approx. 10 – 20 minutes
of burning, you may add 1 – 2 pieces of split logs. Again after app 10 minutes (or after the
logs have caught fire) the air control handle can be pushed in step by step to dampen the
fire. Never, however, completely reduce the air intake while logs are still burning. This will
cause incomplete combustion and soot up the glass.
Tip.
Always leave a few inches of ashes in the firebox for better insulation.
When firing with closed door and correct air intake you do not have to supervise your RAIS
wood-burning stove.
RAIS Malta/RAIS is developed to a nominal thermal output of 7 kW, which corresponds
app 2,0 kg wood/hour with a water content of 18 %. If the fire is fed more than
recommended (exceeding 7 – 9 kW) there is a danger that the stove will be overloaded
and might discolour. Over firing us unnecessary and will void the guarantee.
Firewood
Burn only wood that has been seasoned for at least one full year (2 years is best !). If the
wood has not been “seasoned” or dried, much of the energy of the fire will go into
evaporating the water.
