Glow-worm Ultracom 18sxi Installation And Servicing page 23

10 Standard Flue - Length, Preparation and Installation
10.6 Flue Length
The maximum permissible horizontal flue length is 10 metres
plus the flue terminal assembly, this can be achieved by use
of the accessories, see diagram 10.12.
However should additional 87.5 o or 2 x 45 o elbows be used
then the length MUST be reduced by 1metre.
The diagram 10.10 shows the length achievable by using the
kit A2043400.
When extension pipes are used the flue system must be
designed to have a continuous fall to the boiler of at least 2.5 o
44mm/metre to allow condensate to run back into the boiler
and out via the condensate drain.
The flue can be installed from inside the building, when
access to the outside wall face is not practicable.
Multiple Boiler Chimney Flue Length
The flue length must be calculated and installed according to
the relevant standards EN 13384-1 and 2 (C43 flue systems
only) with reference to the table below and the manufacturers
instructions supplied.
The appliance maximum flue length must be included when
calculating the overall design of the flue system. NOTE: The
horizontal flue terminal must be removed, see diagram 10.11.
MODEL
Exhaust mass rate (g/s)
At Min Thermal
Load (40C°/30°C)
At Max Thermal
Load (80C°/60°C)
Exhaust temperature (ºC)
At Min Thermal
Load (40C°/30°C)
At Max Thermal
Load (80C°/60°C)
18sxi 30sxi
2.30 2.45
8.75 13.25
56.0 44.0
69.0 57.0
Standard Horizontal Flue
220
505mm
55mm
170
Diagram 10.10
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