Ferroli Domina 80 E Installation, Service And User Instructions Manual page 31

3.08.2 Two pipe flue system
• Calculating maximum permissible flue length.
The calculation method is based on a standard reference parameter (1 metre of horizontal air flue 80
diameter 80) for the maximum length permissible for all the pipes + fittings flow resistance coefficient.
In other words, for all components and pipes in the different installation configurations (vertical or hori-
zontal, air or flue, etc.) and for all the fittings, a flow resistance (reduction) equivalent to x metre of
horizontal air induction pipe is indicated. For every boiler model a maximum pipe length is provided,
expressed in n metres of horizontal air pipe.
In this way, to calculate the length of a proposed 2 pipe air-flue system, add the flow resistance (reduction)
in equivalent metres-air. For every component and fitting present in the system, and to check that the total
is less than the maximum length the permissible for the boiler model.
IMPORTANT: the pipes and fittings flow resistance (reduction) have been summarised on the fol-
lowing pages. The flow resistance values written refer only to Ferroli pipes and fittings.
CALCULATION ROUTINE
1. Utilise the pipes and fittings flows resistance tables on the following pages and calculate the total
flow resistance in metres-air, by adding the flow resistances of the components in the whole air-flue
system, based on their position (vertical or horizontal, air inlet or flue outlet).
Please note that the same fitting, identified by a one code (i.e. 1 pipe diameter 80, code KWMA83A),
can offer different flow resistances if positioned as air inlet or flue outlet, if placed vertically or
horizontally.
The flow resistance of the special two pipe flue-air adapters do not have to be included in the
calculation as they are already included in the maximum length calculation.
2. For the restrictors, please refer to cap. 3.06 to determinate the correct diaphragm.
3. Check that the total flow resistance calculated is less or equal to 48 metre, the maximum permissible
for Domina 80E.
DOMINA 80 E
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