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1.9 Draught
If smoke comes out of the stove when the re door is opened, it will be due to the poor
draught in the chimney. This type of stove requires at least 12 PA of chimney draught to
achieve satisfactory combustion, and to prevent smoke from escaping. Smoke may, how-
ever, escape in any event, if the stove door is opened during very vigorous burning, so this
should be avoided.
The ue gas temperature at the rated output is 256°C relative to 20°C.
If in doubt, you may want to get your chimney sweep to measure the draught in the chimney.
Draught
The draught in the chimney is the result of the dierence between the high
temperature in the chimney and the cooler temperature outside. Other factors
that determine whether enough negative pressure can be produced to create a
draught include the length and insulation of the chimney, and wind and weather
conditions.
The draught will be reduced when:
- The temperature dierence is too low, e.g. in connection with a poorly insulated
chimney. If the chimney is cold, it may help to light (burn up) a rolled-up news-
paper in the chimney’s cleaning door.
- The outside temperature is too high, for example during the summer.
- There is no wind.
- The chimney is not tall enough, with the result that it sits in the lee of the roof
surface or tall trees. These conditions are also associated with the greatest risk
of smoke coming back down the chimney.
- Air is entering the chimney in undesired places, e.g. through cracked joints or
leaks in the cleaning door or the ue pipe.
- Unsealed, unused replaces are connected to the chimney.
- The ue pipe and chimney are clogged up with soot, due to inadequate cleaning.
- The house is too tightly sealed (please see the section on Fresh air supply).
- Too little air is getting in.
A good draught is achieved when:
- There is a big dierence between the temperature in the chimney and outside
during ring, i.e. when the need for heating is greatest.
- The weather is clear and there is a good wind.
- The chimney is of the proper height, i.e. at least 4 metres above the stove, and
clear of the spine of the roof.
N.B!
Wood is a material that contains a great deal of gas (approximately 75 %). The ga-
ses are released when the wood is lit and heated up. For this reason, it is important
that the gases are ignited quickly after stoking. If the wood just lies smouldering,
especially after re-stoking, a lot of smoke is created, which, in the worst case, may
cause an explosive ignition of the gasses, resulting in damage to the stove.
sting ames during the combustion process, it is important to let in the required
quantity of oxygen (air supply) at all times.
The setting of the air supply, the method of ignition and the lighting intervals de-
pend on the draught in the chimney, the wind and weather, the amount of heat re-
quired, the fuel, etc. This means that it may take some time before you get to know
the correct functioning of the stove under any given circumstances.
Although you can re your Morsø stove with almost all kinds of wood, you should
not re with wet wood, or unseasoned wood. Wood ought to be stored under
a roof for at least 1 year, and preferably 2 years, with free access to wind. Wood
should be chopped as soon as possible after felling if it is to dry quickly. The wood
can be used once the moisture content is less than 20%. During the EN test, all sto-
ves are tested with wood with a moisture content of (16 ± 4)%.
Never use driftwood, as it usually has a high salt content, which damages both the
stove and the chimney. Impregnated and painted wood and chipboard emit poi-
sonous smoke and fumes, so they should not be used as fuel either.
Please note that liquid fuel may not be used in the stove.
Pieces of wood with a diameter greater than 10 cm should always be chopped.
The pieces of wood should be short enough to be able to lie at over the layer of em-
bers, with air at both ends. The maximum length of fuel in the stove is 30 cm. The ma-
ximum quantity of fuel is 2.5 kg/hour (max. 3 pieces of wood each time you re-stoke).
The rst few times you light the stove, the re should be moderate, so that the heat-
resistant paint can harden before ring more vigorously. During the hardening pha-
se, the paint may develop obnoxious smoke and smell the rst time it is lit, which is
very normal. Make sure that the room is well ventilated during this period.
When heating up or cooling down, the material is exposed to major temperature
dierences that may cause the stove to give o creaking sounds.
2.0 Firing/using the stove
Your stove is constructed with air inlets in two places.
Pre-heated, fast-moving combustion air is added to the re above the glass window, and is
regulated using the handle above the door. The combustion air is let in when the handle is
pushed to the right, and shut o when the handle is pushed to the left.
Another air inlet provides a constant, pre-heated air supply which cannot be adjusted, and
which comes into the combustion chamber just above the re. This helps to burn o the
last few gasses emitted by the wood whilst it is being heated up.
The stove’s rated heat output is 6 kW. Your new Morsø stove is EN-tested for ring with
wood, and is suitable for intermittent use.