Yrittäjäntie 14, FI-27230 Lappi • tel. +358 0207 416 740 • fax +358 0207 416 743 • www.narvi.fi
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Yrittäjäntie 14, FI-27230 Lappi • tel. +358 0207 416 740 • fax +358 0207 416 743 • www.narvi.fi
FI
4. Using the sauna
heater
4.1 Firewood
Only use natural wood logs as fuel. Both hardwood and
softwood can be used to heat the sauna heater. The use of
chipboard, fibreboard, briquet, pellet, painted or impreg-
nated wood, waste or plastic is prohibited. To ensure clean
burning and the largest possible efficiency, the wood must
be dry. The moisture content of the wood must be less
than 20%. Normally good firewood is sticks of wood
the
diameter of which is around 5 cm, length around 33 cm
and weight around 0.5 kg.
Use of liquid fuel is strongly forbidden, also during ignition!
4.2 Heating
Before heating, make sure that there is no combustible
material within the safety clearances. Also make sure that
the ash drawer and fire grate are clean and if the sauna
heater is provided with a water tank, that it is filled with
clean water. Check if there is sufficient draft in the smoke
flue. If you hesitate regarding the draft, check it by burning
a small quantity of paper in the firebox first. During heating
the door of the firebox must be closed and the water tank
must be filled with water. The sauna heater must not be
covered with anything.
To start heating pile firewood over a sufficiently wide area
and ignite it from above. For ignition you may use birch
bark or paper. Ignition aid should be placed between the
upper firewood and it can be topped with some thinner
wood sticks or firewood (see drawing 9). Igniting from
above reduces pollution and ensures cleaner burning.
The power of the sauna heater can be regulated with the
ash drawer. If the ash drawer is closed, the power of the
sauna heater is at its lowest and the burning time is longer.
If the sauna heater soughs too much, reduce the draft. To
do this close the ash drawer half way or completely. This
way heat reaches better the sauna heater, stones can store
heat and you do not just heat up the flue. A calm flame is
a sign of a correct draft. Avoid heating the sauna heater so
that the channels of the stone basket glow red for a long
time because this will overload the firebox and the service life
of the sauna heater will be reduced. Overheating may also
cause excessive heating of the smoke flue and cause fire
hazard. The connective flue pipe must not be glowing red.
Figure 6.
Proper stacking of firewood.
The following table shows the recommended quantities of
firewood for different types of sauna heaters and positions
of the ash drawer. The values shown in the table meet the
values of the nominal power test pursuant to the standard
EN15821. In the test the size of the sauna was determined
based on the maximum area for the given sauna heater and
temperature of 90 °C was achieved in the sauna.
During first
times we recommend using less firewood for achieving
the desired temperature than the values presented in the
table. Maximum quantity of firewood per hour (max. kg/h)
indicated in the table must not be exceeded.
Narvi Black sauna heater
16
20
20VS
24
1. quantity
quantity of firewood (kg)
4
3,5
3,5
4,5
opening of the ash drawer (mm)
20
20
20
20
1. addition
quantity of firewood (kg)
3
3
3
3,5
opening of the ash drawer (mm)
10
10
10
10
2. addition
quantity of firewood (kg)
-
2,5
2,5
3,5
opening of the ash drawer (mm)
-
10
10
10
max kg/h
6
7
7
8
Heating of the sauna:
(The cleaved log that is about 5 cm in diameter and about 33 cm long weighs about 0.5 kg)
EN
