Fer FERSYSTEM TECH 31 C Instructions For Use, Installation And Maintenance page 19

FERSYSTEM TECH 31 C
Connection with coaxial pipes
fig. 22 - Examples of connection with coaxial pipes (
For coaxial connection, fit the unit with one of the following starting accessories. For the wall hole dimensions, refer to
sec. 4.1. Any horizontal sections of the fume exhaust must be kept sloping slightly towards the boiler, to prevent pos-
sible condensate from flowing back towards the outside and causing dripping.
Before proceeding with installation, check with table 2 that the maximum permissible length is not exceeded, bearing
in mind that every coaxial bend gives rise to the reduction indicated in the table. For example, a Ø 60/100 duct compris-
ing a 90° bend + 1 horizontal metre has a total equivalent length of 2 metres.
Table. 2 - Max. length coaxial ducts
Max. permissible length
Reduction factor 90° bend
Reduction factor 45° bend
Starting accessory for coaxial ducts
Coaxial 60/100
5 m
1 m
0.5 m
Cod. 3540U320 - 09/2009 (Rev. 00)
= Air / = Fumes)
Coaxial 80/125
15 m
0.5 m
0.25 m
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