2.2.2
Roof
extraction
by
means
of
a
traditional
flue
Pellet
combustion
fumes
may
be
extracted
also
using
a
pre
‐
existing
traditional
flue
(figure
2.5),
provided
that
it
is
made
to
standard
(refer
to
standard
UNI
10683).
Below
is
a
short
list
of
some
of
the
main
features
given
in
the
standard
that
characterise
a
good
chimney
(C):
‐
Suitable
insulation
and
proofing
particularly
in
its
outer
section
that
is
exposed
to
the
weather;
‐
Uniform
internal
section
(there
must
be
no
section
restrictions);
‐
Made
of
material
that
is
resistant
to
high
temperatures,
the
action
of
combustion
products
and
the
corrosive
action
of
any
condensation
formed;
‐
Predominantly
vertical
course
with
deviations
from
the
axis
of
no
more
than
45°;
It
is
advisable
to
provide
for
a
chamber
to
collect
solid
matter
and
any
condensation
(R)
that
can
be
inspected
by
means
of
an
airtight
window
(I).
Figure
2.5:
Extraction
by
means
of
a
traditional
flue.