Explanation flue systems
Category in accordance to CE
B23
A flue that evacuates the products of combustion to the outside of
the room containing the appliance. The combustion air is drawn directly from the room.
B33
A flue system which is connected to a common duct system. This common duct system
consists of a single natural draught flue. All pressurized parts of the appliance containing
products of combustion are completely enclosed by parts of the appliance supplying
combustion air. Combustion air is drawn into the appliance from the room by means of a
concentric duct, which encloses the flue. The air enters through defined orifices situated
in the surface of the duct.
C13
Horizontal flue system. Discharge in the outside wall.
Inlet opening for the air supply is in the same pressure zone as the discharge
C33
Vertical flue system. Flue gas discharge via the roof.
Inlet opening for the air supply is in the same pressure zone as the discharge
C43
Joint air supply and flue gas discharge duct (CLV system)
Twin-pipe or concentric
C53
Separate air supply and separate flue gas discharge duct.
Discharging into different pressure zones
C63
Free in the market available flue material with CE approval
C83
Joint air supply and flue gas discharge duct (CLV system)
Discharging into different pressure zones
C93
Air supply and flue gas discharge duct in shaft or ducted: Concentric. Air supply from
existing duct. Flue gas discharge via the roof. Air supply and flue gas discharge are in
the same pressure zone.
Make sure the air inlet is open
and complies to the demands
Make sure the air inlet is open
and complies to the demands
For example : a wall terminal
through the facede.
For example : a vertical roof
terminal.
Do not mix flue materials from
different suppliers.
Only as twin pipe system
Concentric flue system
between the boiler and the
duct.
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