Yrittäjäntie 14, FI-27230 Lappi • tel. +358 0207 416 740 • fax +358 0207 416 743 • www.narvi.fi/en
99
Yrittäjäntie 14, FI-27230 Lappi • tel. +358 0207 416 740 • fax +358 0207 416 743 • www.narvi.fi/en
GB
4. Using the sauna
heater
4.1 firewood
Both hardwood and softwood can be used to heat the
sauna heater. The use of chipboard, fibreboard, painted
or impregnated 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%.
Usually 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 firing!
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 water 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 by 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 it
soughs too much in the sauna heater, reduce the draft. To
do this close the ash drawer halfway or completely. This
way heat reaches better in 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 compartment 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 a fire hazard. The connective flue
pipe must not be glowing red.
Figure 9.
Properly stacked firewood.
The following table shows the recommended quantities
of firewood for different types of sauna heaters and po-
sitions of the ash drawer. The values shown in the table
meet the values of the nominal power pursuant to standard
EN15821. In the test the size of the sauna was determined
based on the maximum area for the given sauna heater
NC sauna heater
16
20
20VS
24
1. firebox of firewood
quantity of firewood (kg)
3
3,5
3,5
4,5
opening of the ash drawer (mm)
20
20
20
25
1. addition
quantity of firewood (kg)
2
3
3
3,5
opening of the ash drawer (mm)
10
10
10
25
2. addition
quantity of firewood (kg)
2
2,5
2,5
3,5
opening of the ash drawer (mm)
10
10
10
10
max kg/h
6
7
7
8
Heating of the sauna:
Figure 9.
(sticks of firewood with a diameter around 5 cm, length around 33 cm and weight around 0.5 kg)