Atag E 22S - Dimensions of the Flue Gas and Air Intake Duct

Installation & Servicing Instructions ATAG E-Series
17
6.7.1 Dimensioning of the flue gas and air intake duct
The flue diameter is determined by the total length of the run, including for the connection
pipe, elbows fittings and terminal covers etc and the type and number of boilers installed
into the system.
An undersized flue pipe can lead to disorders. Look at table 1 for the choice of the system
and the correct diameter. The table below shows the maximum flue lengths with the
different boiler outputs. A longer flue gas length can be achieved by increasing the
diameter to ø 100mm.
Explanation table 1:
Two pipe flue gas system: maximum noted length = distance between boiler and
roof terminal A
Concentric flue gas system: maximum noted length = distance between boiler and
roof terminal B
When using bends the noted value behind every bend should be deducted from the
maximum straight length.
ø80mm
A
in m
E22S Maximum straight lenth 80 30
E22C 87° bend resistance length -1,5
45° bend resistance length -0,8
E32S Maximum straight lenth 80 24
E32C 87° bend resistance length -1,5
45° bend resistance length -0,8
ø60/100mm
B
in m
ø80/125mm
B
in m
E22S Maximum straight lenth 60/100 12 Maximum straight lenth 80/125 30
E22C 87° bend resistance length -1 87° bend resistance length 6
45° bend resistance length -1 45° bend resistance length -2,8
E32S Maximum straight lenth 60/100 8 Maximum straight lenth 80/125 24
E32C 87° bend resistance length -1 87° bend resistance length 0
45° bend resistance length -1 45° bend resistance length 0
Concentric flue system
Two pipe flue system + chimney lining
Dimensions flue gas system and air supply system Table 5
Example:
A 22kW with a
concentric flue gas system
ø60/100mm has according
to the table a maximum flue
straight length of 12m In the
system that is going to be
put in there are 2 x 45°
bends, so the maximum flue
gas length is
12 – ( 2 x -1 ) = 10 meters.