Page | 18
2.2 Fume extraction flue features
The main features characterising the fume extraction flue are given. They are
based on what is set out in standards (See Section 2 INSTALLATION)
-
Inspection valves (I);
-
Maximum height of the pipe directly connected to the heater fume
extraction outlet must be between 2 - 3 m;
-
If it is necessary to have a horizontal section, it is advisable to make it with
a maximum length of 1.5 m and with an incline of 3 - 5% in order to help
the fumes to escape;
-
Use of a cowl that is wind-resistant and rain-resistant in order to avoid a
change in the slight condition of overpressure the flue is in;
i
The reduction in pressure in the flue is necessary so as to help the normal
flow of fumes from the combustion chamber towards the outside, in the
event of a mains power cut.
i
Remember that excess heat disposal is managed in an optimum way from
the electronic control panel (modulation, switch-off stage, etc.).
-
Flues must be made of appropriate materials to resist combustion
products and condensation;
-
Duct insulation particularly on the outside part exposed to the weather.
i
Avoid making completely horizontal sections.
INS