19
Chimney
The
chimney
is a device crowning the flue, used to ease dispersion of
combustion products.
It must satisfy the following requisites:
Have a useful outlet section that is not less than the double
of that of the flue on which it is inserted;
Be conformed in a way to prevent the penetration of rain
and snow into the flue;
Be built in a way that, also in the case of winds from every
direction and inclination, to ensure combustion exhaust.
The outlet height (where height means that which corresponds to the
top of the flue, independently of any chimneys) must be outside of the
so-called reflow zone in order to prevent the formation of counter-
pressures, which prevent free exhaust of the combustion products into
the atmosphere.
It is therefore necessary that the minimum heights, indicated in the
following figures, are respected:
Technical
volume
0
,5
m
0
,5
m
Dista nce > 5 m
Dista nce < 5 m
Distanc e> 1,85 m
Distanc e< 1,85 m
0
,5
m
o
v
e
r
th
e
r
id
g
e
Reflow zone
1
m
m
in
im
u
m
1
5
°
