9
Smoke evacuation duct
The smoke discharge from the boiler is with
positive pressure in relation to the surrounding
environment, so it is essential to guarantee the
tightness of the various chimney joints. The
smoke evacuation duct must be independent
from other equipment.
To guarantee the correct extraction of the
smoke, it is mandatory that the first section of
the chimney be vertical with a height of not
less than 1.5 meters.
The horizontal sections must not be longer
than 1.5 meters with a slope of at least 5%.
The chimney outlet must comply with EN 1856-
2 for built-in masonry chimneys and EN 1856-1
for insulated outdoor chimneys. It must be in
0.5mm thick 316 stainless steel with
dimensions respecting what is indicated in the
equipment characteristics, regarding the smoke
outlet.
diam smoke outlet. 100. The smoke duct must
have a diameter of 100 mm for 2.5 meters
max and must pass through diam. 120 mm
immediately afterwards whose male/female
unions are fitted with a high temperature
silicone gasket (>200ºC) with inverted
installation (male downwards) to prevent
condensation from flowing out of the chimney.
For chimneys over 5 meters high, their section
must change to a diameter of 150 mm after 5
meters. The dimensioning of the smoke duct
must be done considering 0 P
a.
The piping used outdoors must be in double-
walled stainless steel, in order to avoid
condensation and corrosion of the same,
resulting from the thermal shock.
It is forbidden to install dampers, butterflies or
valves that strangle the chimney's draft
capacity.
The fume exhaust capacity depends on several
factors, including the height of the chimney.
Depending on these factors, it may be
necessary to make adjustments to the boiler
operating parameters. Excess draft when it is
not possible to correct it by changing
parameters such as air intake and pellet
loading, it will imply the installation of an air
intake valve to the chimney.
If necessary, contact the technical assistance
service.
7.5.1. Basic requirements
Below are some proposals for the execution of
a chimney, which should be understood as
schemes, not replacing a specialty project.
Figure 4- Example vertical installation
