3
sponds to a diameter of 150 mm. If a
damper is fitted in the flue gas pipe,
there must always be at least 20 cm
2
of free passage, even when the damper is in its “closed” position. If local
regulations permit, two contained fireplaces can be connected to the same
chimney. However, you must abide
by local regulations regarding the distance between the two connections.
Wood-burning stoves must never be
connected to chimneys that are also
linked to a gasfired heater. An effi-
cient stove makes high demand on
chimney properties – so always have
your local chimney sweep evaluate
your chimney.
Connection to a brick chimney
Brick a thimble into the chimney and
seat the flue gas pipe in this. The
thimble and flue gas pipe must not
penetrate the chimney opening itself, but must be flush with the inside
of the chimney duct. Joins between
brickwork, the thimble and flue gas
pipe must be sealed with fireproof
material and/or beading
Connection to a steel chimney
When fitting a connection from a top
output stove directly to a steel chimney, we recommend fitting the chimney tube inside the flue gas spigot so
that any soot and condensation drops
into the stove itself rather than collecting on the exterior surface of the
stove.
Changing from top to back outlet - see
figure 2-11 on page XX.
For connections to chimneys that are
run through ceilings, all national and
local regulations regarding distance
to flammable material must be followed. It is important that the chimney
is fitted with roof support so that the
top panel of the stove is not required
to bear the entire weight of the chimney (excessive weight may damage
the stove).
Draft conditions
Poor draft may result in smoke being
emitted from the stove when the door
is opened. The minimum chimney
draft - see table on page 9. The flue
gas temperature at nominal output
is 257°C when expelled to an exterior
temperature of 20°C and the flue gas
mass flow - see table on page 9.
However, there will still be a risk of
smoke emission if the firing door is
opened during powerful firing. The
chimney draft is generated by the difference between the high temperature of the chimney and the low temperature of the fresh air. The length
and insulation of the chimney, wind
and weather conditions also have an
effect on the ability of the chimney to
generate appropriate under-pressure.
If the stove has not been used in a
while, check that the chimney and
stove are not blocked with soot, bird
nests, etc., before using it.
Reduced draft can occur when:
- The difference in temperature is too
small – due to insufficient chimney insulation, for example.
- The outdoor temperature is too
high – in summer, for example.
- No wind is blowing. - The chimney
is too low and sheltered. - The chimney contains false air.
- The chimney and flue gas pipe are
blocked.
- The house is too airtight (i.e. when
there is an insufficient supply of fresh
air).
- Poor smoke extraction (poor draft
conditions) due to a cold chimney or
bad weather conditions can be compensated for by increasing the airflow into the stove.
Good draft occurs when:
- The difference in temperature bet-
ween the chimney and outdoor air
is high.